xref: /openbmc/linux/net/core/dev.c (revision ad4455c6)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      NET3    Protocol independent device support routines.
4  *
5  *	Derived from the non IP parts of dev.c 1.0.19
6  *              Authors:	Ross Biro
7  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
8  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
9  *
10  *	Additional Authors:
11  *		Florian la Roche <rzsfl@rz.uni-sb.de>
12  *		Alan Cox <gw4pts@gw4pts.ampr.org>
13  *		David Hinds <dahinds@users.sourceforge.net>
14  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
15  *		Adam Sulmicki <adam@cfar.umd.edu>
16  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
17  *
18  *	Changes:
19  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
20  *                                      to 2 if register_netdev gets called
21  *                                      before net_dev_init & also removed a
22  *                                      few lines of code in the process.
23  *		Alan Cox	:	device private ioctl copies fields back.
24  *		Alan Cox	:	Transmit queue code does relevant
25  *					stunts to keep the queue safe.
26  *		Alan Cox	:	Fixed double lock.
27  *		Alan Cox	:	Fixed promisc NULL pointer trap
28  *		????????	:	Support the full private ioctl range
29  *		Alan Cox	:	Moved ioctl permission check into
30  *					drivers
31  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
32  *		Alan Cox	:	100 backlog just doesn't cut it when
33  *					you start doing multicast video 8)
34  *		Alan Cox	:	Rewrote net_bh and list manager.
35  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
36  *		Alan Cox	:	Took out transmit every packet pass
37  *					Saved a few bytes in the ioctl handler
38  *		Alan Cox	:	Network driver sets packet type before
39  *					calling netif_rx. Saves a function
40  *					call a packet.
41  *		Alan Cox	:	Hashed net_bh()
42  *		Richard Kooijman:	Timestamp fixes.
43  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
44  *		Alan Cox	:	Device lock protection.
45  *              Alan Cox        :       Fixed nasty side effect of device close
46  *					changes.
47  *		Rudi Cilibrasi	:	Pass the right thing to
48  *					set_mac_address()
49  *		Dave Miller	:	32bit quantity for the device lock to
50  *					make it work out on a Sparc.
51  *		Bjorn Ekwall	:	Added KERNELD hack.
52  *		Alan Cox	:	Cleaned up the backlog initialise.
53  *		Craig Metz	:	SIOCGIFCONF fix if space for under
54  *					1 device.
55  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
56  *					is no device open function.
57  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
58  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
59  *		Cyrus Durgin	:	Cleaned for KMOD
60  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
61  *					A network device unload needs to purge
62  *					the backlog queue.
63  *	Paul Rusty Russell	:	SIOCSIFNAME
64  *              Pekka Riikonen  :	Netdev boot-time settings code
65  *              Andrew Morton   :       Make unregister_netdevice wait
66  *                                      indefinitely on dev->refcnt
67  *              J Hadi Salim    :       - Backlog queue sampling
68  *				        - netif_rx() feedback
69  */
70 
71 #include <linux/uaccess.h>
72 #include <linux/bitops.h>
73 #include <linux/capability.h>
74 #include <linux/cpu.h>
75 #include <linux/types.h>
76 #include <linux/kernel.h>
77 #include <linux/hash.h>
78 #include <linux/slab.h>
79 #include <linux/sched.h>
80 #include <linux/sched/mm.h>
81 #include <linux/mutex.h>
82 #include <linux/rwsem.h>
83 #include <linux/string.h>
84 #include <linux/mm.h>
85 #include <linux/socket.h>
86 #include <linux/sockios.h>
87 #include <linux/errno.h>
88 #include <linux/interrupt.h>
89 #include <linux/if_ether.h>
90 #include <linux/netdevice.h>
91 #include <linux/etherdevice.h>
92 #include <linux/ethtool.h>
93 #include <linux/skbuff.h>
94 #include <linux/kthread.h>
95 #include <linux/bpf.h>
96 #include <linux/bpf_trace.h>
97 #include <net/net_namespace.h>
98 #include <net/sock.h>
99 #include <net/busy_poll.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/stat.h>
102 #include <net/dsa.h>
103 #include <net/dst.h>
104 #include <net/dst_metadata.h>
105 #include <net/gro.h>
106 #include <net/pkt_sched.h>
107 #include <net/pkt_cls.h>
108 #include <net/checksum.h>
109 #include <net/xfrm.h>
110 #include <linux/highmem.h>
111 #include <linux/init.h>
112 #include <linux/module.h>
113 #include <linux/netpoll.h>
114 #include <linux/rcupdate.h>
115 #include <linux/delay.h>
116 #include <net/iw_handler.h>
117 #include <asm/current.h>
118 #include <linux/audit.h>
119 #include <linux/dmaengine.h>
120 #include <linux/err.h>
121 #include <linux/ctype.h>
122 #include <linux/if_arp.h>
123 #include <linux/if_vlan.h>
124 #include <linux/ip.h>
125 #include <net/ip.h>
126 #include <net/mpls.h>
127 #include <linux/ipv6.h>
128 #include <linux/in.h>
129 #include <linux/jhash.h>
130 #include <linux/random.h>
131 #include <trace/events/napi.h>
132 #include <trace/events/net.h>
133 #include <trace/events/skb.h>
134 #include <trace/events/qdisc.h>
135 #include <linux/inetdevice.h>
136 #include <linux/cpu_rmap.h>
137 #include <linux/static_key.h>
138 #include <linux/hashtable.h>
139 #include <linux/vmalloc.h>
140 #include <linux/if_macvlan.h>
141 #include <linux/errqueue.h>
142 #include <linux/hrtimer.h>
143 #include <linux/netfilter_netdev.h>
144 #include <linux/crash_dump.h>
145 #include <linux/sctp.h>
146 #include <net/udp_tunnel.h>
147 #include <linux/net_namespace.h>
148 #include <linux/indirect_call_wrapper.h>
149 #include <net/devlink.h>
150 #include <linux/pm_runtime.h>
151 #include <linux/prandom.h>
152 #include <linux/once_lite.h>
153 
154 #include "dev.h"
155 #include "net-sysfs.h"
156 
157 
158 static DEFINE_SPINLOCK(ptype_lock);
159 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
160 struct list_head ptype_all __read_mostly;	/* Taps */
161 
162 static int netif_rx_internal(struct sk_buff *skb);
163 static int call_netdevice_notifiers_extack(unsigned long val,
164 					   struct net_device *dev,
165 					   struct netlink_ext_ack *extack);
166 static struct napi_struct *napi_by_id(unsigned int napi_id);
167 
168 /*
169  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
170  * semaphore.
171  *
172  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
173  *
174  * Writers must hold the rtnl semaphore while they loop through the
175  * dev_base_head list, and hold dev_base_lock for writing when they do the
176  * actual updates.  This allows pure readers to access the list even
177  * while a writer is preparing to update it.
178  *
179  * To put it another way, dev_base_lock is held for writing only to
180  * protect against pure readers; the rtnl semaphore provides the
181  * protection against other writers.
182  *
183  * See, for example usages, register_netdevice() and
184  * unregister_netdevice(), which must be called with the rtnl
185  * semaphore held.
186  */
187 DEFINE_RWLOCK(dev_base_lock);
188 EXPORT_SYMBOL(dev_base_lock);
189 
190 static DEFINE_MUTEX(ifalias_mutex);
191 
192 /* protects napi_hash addition/deletion and napi_gen_id */
193 static DEFINE_SPINLOCK(napi_hash_lock);
194 
195 static unsigned int napi_gen_id = NR_CPUS;
196 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
197 
198 static DECLARE_RWSEM(devnet_rename_sem);
199 
200 static inline void dev_base_seq_inc(struct net *net)
201 {
202 	while (++net->dev_base_seq == 0)
203 		;
204 }
205 
206 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
207 {
208 	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
209 
210 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
211 }
212 
213 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
214 {
215 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
216 }
217 
218 static inline void rps_lock_irqsave(struct softnet_data *sd,
219 				    unsigned long *flags)
220 {
221 	if (IS_ENABLED(CONFIG_RPS))
222 		spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
223 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
224 		local_irq_save(*flags);
225 }
226 
227 static inline void rps_lock_irq_disable(struct softnet_data *sd)
228 {
229 	if (IS_ENABLED(CONFIG_RPS))
230 		spin_lock_irq(&sd->input_pkt_queue.lock);
231 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
232 		local_irq_disable();
233 }
234 
235 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
236 					  unsigned long *flags)
237 {
238 	if (IS_ENABLED(CONFIG_RPS))
239 		spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
240 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
241 		local_irq_restore(*flags);
242 }
243 
244 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
245 {
246 	if (IS_ENABLED(CONFIG_RPS))
247 		spin_unlock_irq(&sd->input_pkt_queue.lock);
248 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
249 		local_irq_enable();
250 }
251 
252 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
253 						       const char *name)
254 {
255 	struct netdev_name_node *name_node;
256 
257 	name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
258 	if (!name_node)
259 		return NULL;
260 	INIT_HLIST_NODE(&name_node->hlist);
261 	name_node->dev = dev;
262 	name_node->name = name;
263 	return name_node;
264 }
265 
266 static struct netdev_name_node *
267 netdev_name_node_head_alloc(struct net_device *dev)
268 {
269 	struct netdev_name_node *name_node;
270 
271 	name_node = netdev_name_node_alloc(dev, dev->name);
272 	if (!name_node)
273 		return NULL;
274 	INIT_LIST_HEAD(&name_node->list);
275 	return name_node;
276 }
277 
278 static void netdev_name_node_free(struct netdev_name_node *name_node)
279 {
280 	kfree(name_node);
281 }
282 
283 static void netdev_name_node_add(struct net *net,
284 				 struct netdev_name_node *name_node)
285 {
286 	hlist_add_head_rcu(&name_node->hlist,
287 			   dev_name_hash(net, name_node->name));
288 }
289 
290 static void netdev_name_node_del(struct netdev_name_node *name_node)
291 {
292 	hlist_del_rcu(&name_node->hlist);
293 }
294 
295 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
296 							const char *name)
297 {
298 	struct hlist_head *head = dev_name_hash(net, name);
299 	struct netdev_name_node *name_node;
300 
301 	hlist_for_each_entry(name_node, head, hlist)
302 		if (!strcmp(name_node->name, name))
303 			return name_node;
304 	return NULL;
305 }
306 
307 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
308 							    const char *name)
309 {
310 	struct hlist_head *head = dev_name_hash(net, name);
311 	struct netdev_name_node *name_node;
312 
313 	hlist_for_each_entry_rcu(name_node, head, hlist)
314 		if (!strcmp(name_node->name, name))
315 			return name_node;
316 	return NULL;
317 }
318 
319 bool netdev_name_in_use(struct net *net, const char *name)
320 {
321 	return netdev_name_node_lookup(net, name);
322 }
323 EXPORT_SYMBOL(netdev_name_in_use);
324 
325 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
326 {
327 	struct netdev_name_node *name_node;
328 	struct net *net = dev_net(dev);
329 
330 	name_node = netdev_name_node_lookup(net, name);
331 	if (name_node)
332 		return -EEXIST;
333 	name_node = netdev_name_node_alloc(dev, name);
334 	if (!name_node)
335 		return -ENOMEM;
336 	netdev_name_node_add(net, name_node);
337 	/* The node that holds dev->name acts as a head of per-device list. */
338 	list_add_tail(&name_node->list, &dev->name_node->list);
339 
340 	return 0;
341 }
342 
343 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
344 {
345 	list_del(&name_node->list);
346 	netdev_name_node_del(name_node);
347 	kfree(name_node->name);
348 	netdev_name_node_free(name_node);
349 }
350 
351 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
352 {
353 	struct netdev_name_node *name_node;
354 	struct net *net = dev_net(dev);
355 
356 	name_node = netdev_name_node_lookup(net, name);
357 	if (!name_node)
358 		return -ENOENT;
359 	/* lookup might have found our primary name or a name belonging
360 	 * to another device.
361 	 */
362 	if (name_node == dev->name_node || name_node->dev != dev)
363 		return -EINVAL;
364 
365 	__netdev_name_node_alt_destroy(name_node);
366 
367 	return 0;
368 }
369 
370 static void netdev_name_node_alt_flush(struct net_device *dev)
371 {
372 	struct netdev_name_node *name_node, *tmp;
373 
374 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
375 		__netdev_name_node_alt_destroy(name_node);
376 }
377 
378 /* Device list insertion */
379 static void list_netdevice(struct net_device *dev)
380 {
381 	struct net *net = dev_net(dev);
382 
383 	ASSERT_RTNL();
384 
385 	write_lock(&dev_base_lock);
386 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
387 	netdev_name_node_add(net, dev->name_node);
388 	hlist_add_head_rcu(&dev->index_hlist,
389 			   dev_index_hash(net, dev->ifindex));
390 	write_unlock(&dev_base_lock);
391 
392 	dev_base_seq_inc(net);
393 }
394 
395 /* Device list removal
396  * caller must respect a RCU grace period before freeing/reusing dev
397  */
398 static void unlist_netdevice(struct net_device *dev, bool lock)
399 {
400 	ASSERT_RTNL();
401 
402 	/* Unlink dev from the device chain */
403 	if (lock)
404 		write_lock(&dev_base_lock);
405 	list_del_rcu(&dev->dev_list);
406 	netdev_name_node_del(dev->name_node);
407 	hlist_del_rcu(&dev->index_hlist);
408 	if (lock)
409 		write_unlock(&dev_base_lock);
410 
411 	dev_base_seq_inc(dev_net(dev));
412 }
413 
414 /*
415  *	Our notifier list
416  */
417 
418 static RAW_NOTIFIER_HEAD(netdev_chain);
419 
420 /*
421  *	Device drivers call our routines to queue packets here. We empty the
422  *	queue in the local softnet handler.
423  */
424 
425 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
426 EXPORT_PER_CPU_SYMBOL(softnet_data);
427 
428 #ifdef CONFIG_LOCKDEP
429 /*
430  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
431  * according to dev->type
432  */
433 static const unsigned short netdev_lock_type[] = {
434 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
435 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
436 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
437 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
438 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
439 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
440 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
441 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
442 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
443 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
444 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
445 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
446 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
447 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
448 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
449 
450 static const char *const netdev_lock_name[] = {
451 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
452 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
453 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
454 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
455 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
456 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
457 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
458 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
459 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
460 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
461 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
462 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
463 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
464 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
465 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
466 
467 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
468 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
469 
470 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
471 {
472 	int i;
473 
474 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
475 		if (netdev_lock_type[i] == dev_type)
476 			return i;
477 	/* the last key is used by default */
478 	return ARRAY_SIZE(netdev_lock_type) - 1;
479 }
480 
481 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
482 						 unsigned short dev_type)
483 {
484 	int i;
485 
486 	i = netdev_lock_pos(dev_type);
487 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
488 				   netdev_lock_name[i]);
489 }
490 
491 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
492 {
493 	int i;
494 
495 	i = netdev_lock_pos(dev->type);
496 	lockdep_set_class_and_name(&dev->addr_list_lock,
497 				   &netdev_addr_lock_key[i],
498 				   netdev_lock_name[i]);
499 }
500 #else
501 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
502 						 unsigned short dev_type)
503 {
504 }
505 
506 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
507 {
508 }
509 #endif
510 
511 /*******************************************************************************
512  *
513  *		Protocol management and registration routines
514  *
515  *******************************************************************************/
516 
517 
518 /*
519  *	Add a protocol ID to the list. Now that the input handler is
520  *	smarter we can dispense with all the messy stuff that used to be
521  *	here.
522  *
523  *	BEWARE!!! Protocol handlers, mangling input packets,
524  *	MUST BE last in hash buckets and checking protocol handlers
525  *	MUST start from promiscuous ptype_all chain in net_bh.
526  *	It is true now, do not change it.
527  *	Explanation follows: if protocol handler, mangling packet, will
528  *	be the first on list, it is not able to sense, that packet
529  *	is cloned and should be copied-on-write, so that it will
530  *	change it and subsequent readers will get broken packet.
531  *							--ANK (980803)
532  */
533 
534 static inline struct list_head *ptype_head(const struct packet_type *pt)
535 {
536 	if (pt->type == htons(ETH_P_ALL))
537 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
538 	else
539 		return pt->dev ? &pt->dev->ptype_specific :
540 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
541 }
542 
543 /**
544  *	dev_add_pack - add packet handler
545  *	@pt: packet type declaration
546  *
547  *	Add a protocol handler to the networking stack. The passed &packet_type
548  *	is linked into kernel lists and may not be freed until it has been
549  *	removed from the kernel lists.
550  *
551  *	This call does not sleep therefore it can not
552  *	guarantee all CPU's that are in middle of receiving packets
553  *	will see the new packet type (until the next received packet).
554  */
555 
556 void dev_add_pack(struct packet_type *pt)
557 {
558 	struct list_head *head = ptype_head(pt);
559 
560 	spin_lock(&ptype_lock);
561 	list_add_rcu(&pt->list, head);
562 	spin_unlock(&ptype_lock);
563 }
564 EXPORT_SYMBOL(dev_add_pack);
565 
566 /**
567  *	__dev_remove_pack	 - remove packet handler
568  *	@pt: packet type declaration
569  *
570  *	Remove a protocol handler that was previously added to the kernel
571  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
572  *	from the kernel lists and can be freed or reused once this function
573  *	returns.
574  *
575  *      The packet type might still be in use by receivers
576  *	and must not be freed until after all the CPU's have gone
577  *	through a quiescent state.
578  */
579 void __dev_remove_pack(struct packet_type *pt)
580 {
581 	struct list_head *head = ptype_head(pt);
582 	struct packet_type *pt1;
583 
584 	spin_lock(&ptype_lock);
585 
586 	list_for_each_entry(pt1, head, list) {
587 		if (pt == pt1) {
588 			list_del_rcu(&pt->list);
589 			goto out;
590 		}
591 	}
592 
593 	pr_warn("dev_remove_pack: %p not found\n", pt);
594 out:
595 	spin_unlock(&ptype_lock);
596 }
597 EXPORT_SYMBOL(__dev_remove_pack);
598 
599 /**
600  *	dev_remove_pack	 - remove packet handler
601  *	@pt: packet type declaration
602  *
603  *	Remove a protocol handler that was previously added to the kernel
604  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
605  *	from the kernel lists and can be freed or reused once this function
606  *	returns.
607  *
608  *	This call sleeps to guarantee that no CPU is looking at the packet
609  *	type after return.
610  */
611 void dev_remove_pack(struct packet_type *pt)
612 {
613 	__dev_remove_pack(pt);
614 
615 	synchronize_net();
616 }
617 EXPORT_SYMBOL(dev_remove_pack);
618 
619 
620 /*******************************************************************************
621  *
622  *			    Device Interface Subroutines
623  *
624  *******************************************************************************/
625 
626 /**
627  *	dev_get_iflink	- get 'iflink' value of a interface
628  *	@dev: targeted interface
629  *
630  *	Indicates the ifindex the interface is linked to.
631  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
632  */
633 
634 int dev_get_iflink(const struct net_device *dev)
635 {
636 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
637 		return dev->netdev_ops->ndo_get_iflink(dev);
638 
639 	return dev->ifindex;
640 }
641 EXPORT_SYMBOL(dev_get_iflink);
642 
643 /**
644  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
645  *	@dev: targeted interface
646  *	@skb: The packet.
647  *
648  *	For better visibility of tunnel traffic OVS needs to retrieve
649  *	egress tunnel information for a packet. Following API allows
650  *	user to get this info.
651  */
652 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
653 {
654 	struct ip_tunnel_info *info;
655 
656 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
657 		return -EINVAL;
658 
659 	info = skb_tunnel_info_unclone(skb);
660 	if (!info)
661 		return -ENOMEM;
662 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
663 		return -EINVAL;
664 
665 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
666 }
667 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
668 
669 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
670 {
671 	int k = stack->num_paths++;
672 
673 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
674 		return NULL;
675 
676 	return &stack->path[k];
677 }
678 
679 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
680 			  struct net_device_path_stack *stack)
681 {
682 	const struct net_device *last_dev;
683 	struct net_device_path_ctx ctx = {
684 		.dev	= dev,
685 	};
686 	struct net_device_path *path;
687 	int ret = 0;
688 
689 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
690 	stack->num_paths = 0;
691 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
692 		last_dev = ctx.dev;
693 		path = dev_fwd_path(stack);
694 		if (!path)
695 			return -1;
696 
697 		memset(path, 0, sizeof(struct net_device_path));
698 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
699 		if (ret < 0)
700 			return -1;
701 
702 		if (WARN_ON_ONCE(last_dev == ctx.dev))
703 			return -1;
704 	}
705 
706 	if (!ctx.dev)
707 		return ret;
708 
709 	path = dev_fwd_path(stack);
710 	if (!path)
711 		return -1;
712 	path->type = DEV_PATH_ETHERNET;
713 	path->dev = ctx.dev;
714 
715 	return ret;
716 }
717 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
718 
719 /**
720  *	__dev_get_by_name	- find a device by its name
721  *	@net: the applicable net namespace
722  *	@name: name to find
723  *
724  *	Find an interface by name. Must be called under RTNL semaphore
725  *	or @dev_base_lock. If the name is found a pointer to the device
726  *	is returned. If the name is not found then %NULL is returned. The
727  *	reference counters are not incremented so the caller must be
728  *	careful with locks.
729  */
730 
731 struct net_device *__dev_get_by_name(struct net *net, const char *name)
732 {
733 	struct netdev_name_node *node_name;
734 
735 	node_name = netdev_name_node_lookup(net, name);
736 	return node_name ? node_name->dev : NULL;
737 }
738 EXPORT_SYMBOL(__dev_get_by_name);
739 
740 /**
741  * dev_get_by_name_rcu	- find a device by its name
742  * @net: the applicable net namespace
743  * @name: name to find
744  *
745  * Find an interface by name.
746  * If the name is found a pointer to the device is returned.
747  * If the name is not found then %NULL is returned.
748  * The reference counters are not incremented so the caller must be
749  * careful with locks. The caller must hold RCU lock.
750  */
751 
752 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
753 {
754 	struct netdev_name_node *node_name;
755 
756 	node_name = netdev_name_node_lookup_rcu(net, name);
757 	return node_name ? node_name->dev : NULL;
758 }
759 EXPORT_SYMBOL(dev_get_by_name_rcu);
760 
761 /**
762  *	dev_get_by_name		- find a device by its name
763  *	@net: the applicable net namespace
764  *	@name: name to find
765  *
766  *	Find an interface by name. This can be called from any
767  *	context and does its own locking. The returned handle has
768  *	the usage count incremented and the caller must use dev_put() to
769  *	release it when it is no longer needed. %NULL is returned if no
770  *	matching device is found.
771  */
772 
773 struct net_device *dev_get_by_name(struct net *net, const char *name)
774 {
775 	struct net_device *dev;
776 
777 	rcu_read_lock();
778 	dev = dev_get_by_name_rcu(net, name);
779 	dev_hold(dev);
780 	rcu_read_unlock();
781 	return dev;
782 }
783 EXPORT_SYMBOL(dev_get_by_name);
784 
785 /**
786  *	__dev_get_by_index - find a device by its ifindex
787  *	@net: the applicable net namespace
788  *	@ifindex: index of device
789  *
790  *	Search for an interface by index. Returns %NULL if the device
791  *	is not found or a pointer to the device. The device has not
792  *	had its reference counter increased so the caller must be careful
793  *	about locking. The caller must hold either the RTNL semaphore
794  *	or @dev_base_lock.
795  */
796 
797 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
798 {
799 	struct net_device *dev;
800 	struct hlist_head *head = dev_index_hash(net, ifindex);
801 
802 	hlist_for_each_entry(dev, head, index_hlist)
803 		if (dev->ifindex == ifindex)
804 			return dev;
805 
806 	return NULL;
807 }
808 EXPORT_SYMBOL(__dev_get_by_index);
809 
810 /**
811  *	dev_get_by_index_rcu - find a device by its ifindex
812  *	@net: the applicable net namespace
813  *	@ifindex: index of device
814  *
815  *	Search for an interface by index. Returns %NULL if the device
816  *	is not found or a pointer to the device. The device has not
817  *	had its reference counter increased so the caller must be careful
818  *	about locking. The caller must hold RCU lock.
819  */
820 
821 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
822 {
823 	struct net_device *dev;
824 	struct hlist_head *head = dev_index_hash(net, ifindex);
825 
826 	hlist_for_each_entry_rcu(dev, head, index_hlist)
827 		if (dev->ifindex == ifindex)
828 			return dev;
829 
830 	return NULL;
831 }
832 EXPORT_SYMBOL(dev_get_by_index_rcu);
833 
834 
835 /**
836  *	dev_get_by_index - find a device by its ifindex
837  *	@net: the applicable net namespace
838  *	@ifindex: index of device
839  *
840  *	Search for an interface by index. Returns NULL if the device
841  *	is not found or a pointer to the device. The device returned has
842  *	had a reference added and the pointer is safe until the user calls
843  *	dev_put to indicate they have finished with it.
844  */
845 
846 struct net_device *dev_get_by_index(struct net *net, int ifindex)
847 {
848 	struct net_device *dev;
849 
850 	rcu_read_lock();
851 	dev = dev_get_by_index_rcu(net, ifindex);
852 	dev_hold(dev);
853 	rcu_read_unlock();
854 	return dev;
855 }
856 EXPORT_SYMBOL(dev_get_by_index);
857 
858 /**
859  *	dev_get_by_napi_id - find a device by napi_id
860  *	@napi_id: ID of the NAPI struct
861  *
862  *	Search for an interface by NAPI ID. Returns %NULL if the device
863  *	is not found or a pointer to the device. The device has not had
864  *	its reference counter increased so the caller must be careful
865  *	about locking. The caller must hold RCU lock.
866  */
867 
868 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
869 {
870 	struct napi_struct *napi;
871 
872 	WARN_ON_ONCE(!rcu_read_lock_held());
873 
874 	if (napi_id < MIN_NAPI_ID)
875 		return NULL;
876 
877 	napi = napi_by_id(napi_id);
878 
879 	return napi ? napi->dev : NULL;
880 }
881 EXPORT_SYMBOL(dev_get_by_napi_id);
882 
883 /**
884  *	netdev_get_name - get a netdevice name, knowing its ifindex.
885  *	@net: network namespace
886  *	@name: a pointer to the buffer where the name will be stored.
887  *	@ifindex: the ifindex of the interface to get the name from.
888  */
889 int netdev_get_name(struct net *net, char *name, int ifindex)
890 {
891 	struct net_device *dev;
892 	int ret;
893 
894 	down_read(&devnet_rename_sem);
895 	rcu_read_lock();
896 
897 	dev = dev_get_by_index_rcu(net, ifindex);
898 	if (!dev) {
899 		ret = -ENODEV;
900 		goto out;
901 	}
902 
903 	strcpy(name, dev->name);
904 
905 	ret = 0;
906 out:
907 	rcu_read_unlock();
908 	up_read(&devnet_rename_sem);
909 	return ret;
910 }
911 
912 /**
913  *	dev_getbyhwaddr_rcu - find a device by its hardware address
914  *	@net: the applicable net namespace
915  *	@type: media type of device
916  *	@ha: hardware address
917  *
918  *	Search for an interface by MAC address. Returns NULL if the device
919  *	is not found or a pointer to the device.
920  *	The caller must hold RCU or RTNL.
921  *	The returned device has not had its ref count increased
922  *	and the caller must therefore be careful about locking
923  *
924  */
925 
926 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
927 				       const char *ha)
928 {
929 	struct net_device *dev;
930 
931 	for_each_netdev_rcu(net, dev)
932 		if (dev->type == type &&
933 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
934 			return dev;
935 
936 	return NULL;
937 }
938 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
939 
940 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
941 {
942 	struct net_device *dev, *ret = NULL;
943 
944 	rcu_read_lock();
945 	for_each_netdev_rcu(net, dev)
946 		if (dev->type == type) {
947 			dev_hold(dev);
948 			ret = dev;
949 			break;
950 		}
951 	rcu_read_unlock();
952 	return ret;
953 }
954 EXPORT_SYMBOL(dev_getfirstbyhwtype);
955 
956 /**
957  *	__dev_get_by_flags - find any device with given flags
958  *	@net: the applicable net namespace
959  *	@if_flags: IFF_* values
960  *	@mask: bitmask of bits in if_flags to check
961  *
962  *	Search for any interface with the given flags. Returns NULL if a device
963  *	is not found or a pointer to the device. Must be called inside
964  *	rtnl_lock(), and result refcount is unchanged.
965  */
966 
967 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
968 				      unsigned short mask)
969 {
970 	struct net_device *dev, *ret;
971 
972 	ASSERT_RTNL();
973 
974 	ret = NULL;
975 	for_each_netdev(net, dev) {
976 		if (((dev->flags ^ if_flags) & mask) == 0) {
977 			ret = dev;
978 			break;
979 		}
980 	}
981 	return ret;
982 }
983 EXPORT_SYMBOL(__dev_get_by_flags);
984 
985 /**
986  *	dev_valid_name - check if name is okay for network device
987  *	@name: name string
988  *
989  *	Network device names need to be valid file names to
990  *	allow sysfs to work.  We also disallow any kind of
991  *	whitespace.
992  */
993 bool dev_valid_name(const char *name)
994 {
995 	if (*name == '\0')
996 		return false;
997 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
998 		return false;
999 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1000 		return false;
1001 
1002 	while (*name) {
1003 		if (*name == '/' || *name == ':' || isspace(*name))
1004 			return false;
1005 		name++;
1006 	}
1007 	return true;
1008 }
1009 EXPORT_SYMBOL(dev_valid_name);
1010 
1011 /**
1012  *	__dev_alloc_name - allocate a name for a device
1013  *	@net: network namespace to allocate the device name in
1014  *	@name: name format string
1015  *	@buf:  scratch buffer and result name string
1016  *
1017  *	Passed a format string - eg "lt%d" it will try and find a suitable
1018  *	id. It scans list of devices to build up a free map, then chooses
1019  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1020  *	while allocating the name and adding the device in order to avoid
1021  *	duplicates.
1022  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1023  *	Returns the number of the unit assigned or a negative errno code.
1024  */
1025 
1026 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1027 {
1028 	int i = 0;
1029 	const char *p;
1030 	const int max_netdevices = 8*PAGE_SIZE;
1031 	unsigned long *inuse;
1032 	struct net_device *d;
1033 
1034 	if (!dev_valid_name(name))
1035 		return -EINVAL;
1036 
1037 	p = strchr(name, '%');
1038 	if (p) {
1039 		/*
1040 		 * Verify the string as this thing may have come from
1041 		 * the user.  There must be either one "%d" and no other "%"
1042 		 * characters.
1043 		 */
1044 		if (p[1] != 'd' || strchr(p + 2, '%'))
1045 			return -EINVAL;
1046 
1047 		/* Use one page as a bit array of possible slots */
1048 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1049 		if (!inuse)
1050 			return -ENOMEM;
1051 
1052 		for_each_netdev(net, d) {
1053 			struct netdev_name_node *name_node;
1054 			list_for_each_entry(name_node, &d->name_node->list, list) {
1055 				if (!sscanf(name_node->name, name, &i))
1056 					continue;
1057 				if (i < 0 || i >= max_netdevices)
1058 					continue;
1059 
1060 				/*  avoid cases where sscanf is not exact inverse of printf */
1061 				snprintf(buf, IFNAMSIZ, name, i);
1062 				if (!strncmp(buf, name_node->name, IFNAMSIZ))
1063 					__set_bit(i, inuse);
1064 			}
1065 			if (!sscanf(d->name, name, &i))
1066 				continue;
1067 			if (i < 0 || i >= max_netdevices)
1068 				continue;
1069 
1070 			/*  avoid cases where sscanf is not exact inverse of printf */
1071 			snprintf(buf, IFNAMSIZ, name, i);
1072 			if (!strncmp(buf, d->name, IFNAMSIZ))
1073 				__set_bit(i, inuse);
1074 		}
1075 
1076 		i = find_first_zero_bit(inuse, max_netdevices);
1077 		free_page((unsigned long) inuse);
1078 	}
1079 
1080 	snprintf(buf, IFNAMSIZ, name, i);
1081 	if (!netdev_name_in_use(net, buf))
1082 		return i;
1083 
1084 	/* It is possible to run out of possible slots
1085 	 * when the name is long and there isn't enough space left
1086 	 * for the digits, or if all bits are used.
1087 	 */
1088 	return -ENFILE;
1089 }
1090 
1091 static int dev_alloc_name_ns(struct net *net,
1092 			     struct net_device *dev,
1093 			     const char *name)
1094 {
1095 	char buf[IFNAMSIZ];
1096 	int ret;
1097 
1098 	BUG_ON(!net);
1099 	ret = __dev_alloc_name(net, name, buf);
1100 	if (ret >= 0)
1101 		strscpy(dev->name, buf, IFNAMSIZ);
1102 	return ret;
1103 }
1104 
1105 /**
1106  *	dev_alloc_name - allocate a name for a device
1107  *	@dev: device
1108  *	@name: name format string
1109  *
1110  *	Passed a format string - eg "lt%d" it will try and find a suitable
1111  *	id. It scans list of devices to build up a free map, then chooses
1112  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1113  *	while allocating the name and adding the device in order to avoid
1114  *	duplicates.
1115  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1116  *	Returns the number of the unit assigned or a negative errno code.
1117  */
1118 
1119 int dev_alloc_name(struct net_device *dev, const char *name)
1120 {
1121 	return dev_alloc_name_ns(dev_net(dev), dev, name);
1122 }
1123 EXPORT_SYMBOL(dev_alloc_name);
1124 
1125 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1126 			      const char *name)
1127 {
1128 	BUG_ON(!net);
1129 
1130 	if (!dev_valid_name(name))
1131 		return -EINVAL;
1132 
1133 	if (strchr(name, '%'))
1134 		return dev_alloc_name_ns(net, dev, name);
1135 	else if (netdev_name_in_use(net, name))
1136 		return -EEXIST;
1137 	else if (dev->name != name)
1138 		strscpy(dev->name, name, IFNAMSIZ);
1139 
1140 	return 0;
1141 }
1142 
1143 /**
1144  *	dev_change_name - change name of a device
1145  *	@dev: device
1146  *	@newname: name (or format string) must be at least IFNAMSIZ
1147  *
1148  *	Change name of a device, can pass format strings "eth%d".
1149  *	for wildcarding.
1150  */
1151 int dev_change_name(struct net_device *dev, const char *newname)
1152 {
1153 	unsigned char old_assign_type;
1154 	char oldname[IFNAMSIZ];
1155 	int err = 0;
1156 	int ret;
1157 	struct net *net;
1158 
1159 	ASSERT_RTNL();
1160 	BUG_ON(!dev_net(dev));
1161 
1162 	net = dev_net(dev);
1163 
1164 	down_write(&devnet_rename_sem);
1165 
1166 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1167 		up_write(&devnet_rename_sem);
1168 		return 0;
1169 	}
1170 
1171 	memcpy(oldname, dev->name, IFNAMSIZ);
1172 
1173 	err = dev_get_valid_name(net, dev, newname);
1174 	if (err < 0) {
1175 		up_write(&devnet_rename_sem);
1176 		return err;
1177 	}
1178 
1179 	if (oldname[0] && !strchr(oldname, '%'))
1180 		netdev_info(dev, "renamed from %s%s\n", oldname,
1181 			    dev->flags & IFF_UP ? " (while UP)" : "");
1182 
1183 	old_assign_type = dev->name_assign_type;
1184 	dev->name_assign_type = NET_NAME_RENAMED;
1185 
1186 rollback:
1187 	ret = device_rename(&dev->dev, dev->name);
1188 	if (ret) {
1189 		memcpy(dev->name, oldname, IFNAMSIZ);
1190 		dev->name_assign_type = old_assign_type;
1191 		up_write(&devnet_rename_sem);
1192 		return ret;
1193 	}
1194 
1195 	up_write(&devnet_rename_sem);
1196 
1197 	netdev_adjacent_rename_links(dev, oldname);
1198 
1199 	write_lock(&dev_base_lock);
1200 	netdev_name_node_del(dev->name_node);
1201 	write_unlock(&dev_base_lock);
1202 
1203 	synchronize_rcu();
1204 
1205 	write_lock(&dev_base_lock);
1206 	netdev_name_node_add(net, dev->name_node);
1207 	write_unlock(&dev_base_lock);
1208 
1209 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1210 	ret = notifier_to_errno(ret);
1211 
1212 	if (ret) {
1213 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1214 		if (err >= 0) {
1215 			err = ret;
1216 			down_write(&devnet_rename_sem);
1217 			memcpy(dev->name, oldname, IFNAMSIZ);
1218 			memcpy(oldname, newname, IFNAMSIZ);
1219 			dev->name_assign_type = old_assign_type;
1220 			old_assign_type = NET_NAME_RENAMED;
1221 			goto rollback;
1222 		} else {
1223 			netdev_err(dev, "name change rollback failed: %d\n",
1224 				   ret);
1225 		}
1226 	}
1227 
1228 	return err;
1229 }
1230 
1231 /**
1232  *	dev_set_alias - change ifalias of a device
1233  *	@dev: device
1234  *	@alias: name up to IFALIASZ
1235  *	@len: limit of bytes to copy from info
1236  *
1237  *	Set ifalias for a device,
1238  */
1239 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1240 {
1241 	struct dev_ifalias *new_alias = NULL;
1242 
1243 	if (len >= IFALIASZ)
1244 		return -EINVAL;
1245 
1246 	if (len) {
1247 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1248 		if (!new_alias)
1249 			return -ENOMEM;
1250 
1251 		memcpy(new_alias->ifalias, alias, len);
1252 		new_alias->ifalias[len] = 0;
1253 	}
1254 
1255 	mutex_lock(&ifalias_mutex);
1256 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1257 					mutex_is_locked(&ifalias_mutex));
1258 	mutex_unlock(&ifalias_mutex);
1259 
1260 	if (new_alias)
1261 		kfree_rcu(new_alias, rcuhead);
1262 
1263 	return len;
1264 }
1265 EXPORT_SYMBOL(dev_set_alias);
1266 
1267 /**
1268  *	dev_get_alias - get ifalias of a device
1269  *	@dev: device
1270  *	@name: buffer to store name of ifalias
1271  *	@len: size of buffer
1272  *
1273  *	get ifalias for a device.  Caller must make sure dev cannot go
1274  *	away,  e.g. rcu read lock or own a reference count to device.
1275  */
1276 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1277 {
1278 	const struct dev_ifalias *alias;
1279 	int ret = 0;
1280 
1281 	rcu_read_lock();
1282 	alias = rcu_dereference(dev->ifalias);
1283 	if (alias)
1284 		ret = snprintf(name, len, "%s", alias->ifalias);
1285 	rcu_read_unlock();
1286 
1287 	return ret;
1288 }
1289 
1290 /**
1291  *	netdev_features_change - device changes features
1292  *	@dev: device to cause notification
1293  *
1294  *	Called to indicate a device has changed features.
1295  */
1296 void netdev_features_change(struct net_device *dev)
1297 {
1298 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1299 }
1300 EXPORT_SYMBOL(netdev_features_change);
1301 
1302 /**
1303  *	netdev_state_change - device changes state
1304  *	@dev: device to cause notification
1305  *
1306  *	Called to indicate a device has changed state. This function calls
1307  *	the notifier chains for netdev_chain and sends a NEWLINK message
1308  *	to the routing socket.
1309  */
1310 void netdev_state_change(struct net_device *dev)
1311 {
1312 	if (dev->flags & IFF_UP) {
1313 		struct netdev_notifier_change_info change_info = {
1314 			.info.dev = dev,
1315 		};
1316 
1317 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1318 					      &change_info.info);
1319 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1320 	}
1321 }
1322 EXPORT_SYMBOL(netdev_state_change);
1323 
1324 /**
1325  * __netdev_notify_peers - notify network peers about existence of @dev,
1326  * to be called when rtnl lock is already held.
1327  * @dev: network device
1328  *
1329  * Generate traffic such that interested network peers are aware of
1330  * @dev, such as by generating a gratuitous ARP. This may be used when
1331  * a device wants to inform the rest of the network about some sort of
1332  * reconfiguration such as a failover event or virtual machine
1333  * migration.
1334  */
1335 void __netdev_notify_peers(struct net_device *dev)
1336 {
1337 	ASSERT_RTNL();
1338 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1339 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1340 }
1341 EXPORT_SYMBOL(__netdev_notify_peers);
1342 
1343 /**
1344  * netdev_notify_peers - notify network peers about existence of @dev
1345  * @dev: network device
1346  *
1347  * Generate traffic such that interested network peers are aware of
1348  * @dev, such as by generating a gratuitous ARP. This may be used when
1349  * a device wants to inform the rest of the network about some sort of
1350  * reconfiguration such as a failover event or virtual machine
1351  * migration.
1352  */
1353 void netdev_notify_peers(struct net_device *dev)
1354 {
1355 	rtnl_lock();
1356 	__netdev_notify_peers(dev);
1357 	rtnl_unlock();
1358 }
1359 EXPORT_SYMBOL(netdev_notify_peers);
1360 
1361 static int napi_threaded_poll(void *data);
1362 
1363 static int napi_kthread_create(struct napi_struct *n)
1364 {
1365 	int err = 0;
1366 
1367 	/* Create and wake up the kthread once to put it in
1368 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1369 	 * warning and work with loadavg.
1370 	 */
1371 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1372 				n->dev->name, n->napi_id);
1373 	if (IS_ERR(n->thread)) {
1374 		err = PTR_ERR(n->thread);
1375 		pr_err("kthread_run failed with err %d\n", err);
1376 		n->thread = NULL;
1377 	}
1378 
1379 	return err;
1380 }
1381 
1382 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1383 {
1384 	const struct net_device_ops *ops = dev->netdev_ops;
1385 	int ret;
1386 
1387 	ASSERT_RTNL();
1388 	dev_addr_check(dev);
1389 
1390 	if (!netif_device_present(dev)) {
1391 		/* may be detached because parent is runtime-suspended */
1392 		if (dev->dev.parent)
1393 			pm_runtime_resume(dev->dev.parent);
1394 		if (!netif_device_present(dev))
1395 			return -ENODEV;
1396 	}
1397 
1398 	/* Block netpoll from trying to do any rx path servicing.
1399 	 * If we don't do this there is a chance ndo_poll_controller
1400 	 * or ndo_poll may be running while we open the device
1401 	 */
1402 	netpoll_poll_disable(dev);
1403 
1404 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1405 	ret = notifier_to_errno(ret);
1406 	if (ret)
1407 		return ret;
1408 
1409 	set_bit(__LINK_STATE_START, &dev->state);
1410 
1411 	if (ops->ndo_validate_addr)
1412 		ret = ops->ndo_validate_addr(dev);
1413 
1414 	if (!ret && ops->ndo_open)
1415 		ret = ops->ndo_open(dev);
1416 
1417 	netpoll_poll_enable(dev);
1418 
1419 	if (ret)
1420 		clear_bit(__LINK_STATE_START, &dev->state);
1421 	else {
1422 		dev->flags |= IFF_UP;
1423 		dev_set_rx_mode(dev);
1424 		dev_activate(dev);
1425 		add_device_randomness(dev->dev_addr, dev->addr_len);
1426 	}
1427 
1428 	return ret;
1429 }
1430 
1431 /**
1432  *	dev_open	- prepare an interface for use.
1433  *	@dev: device to open
1434  *	@extack: netlink extended ack
1435  *
1436  *	Takes a device from down to up state. The device's private open
1437  *	function is invoked and then the multicast lists are loaded. Finally
1438  *	the device is moved into the up state and a %NETDEV_UP message is
1439  *	sent to the netdev notifier chain.
1440  *
1441  *	Calling this function on an active interface is a nop. On a failure
1442  *	a negative errno code is returned.
1443  */
1444 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1445 {
1446 	int ret;
1447 
1448 	if (dev->flags & IFF_UP)
1449 		return 0;
1450 
1451 	ret = __dev_open(dev, extack);
1452 	if (ret < 0)
1453 		return ret;
1454 
1455 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1456 	call_netdevice_notifiers(NETDEV_UP, dev);
1457 
1458 	return ret;
1459 }
1460 EXPORT_SYMBOL(dev_open);
1461 
1462 static void __dev_close_many(struct list_head *head)
1463 {
1464 	struct net_device *dev;
1465 
1466 	ASSERT_RTNL();
1467 	might_sleep();
1468 
1469 	list_for_each_entry(dev, head, close_list) {
1470 		/* Temporarily disable netpoll until the interface is down */
1471 		netpoll_poll_disable(dev);
1472 
1473 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1474 
1475 		clear_bit(__LINK_STATE_START, &dev->state);
1476 
1477 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1478 		 * can be even on different cpu. So just clear netif_running().
1479 		 *
1480 		 * dev->stop() will invoke napi_disable() on all of it's
1481 		 * napi_struct instances on this device.
1482 		 */
1483 		smp_mb__after_atomic(); /* Commit netif_running(). */
1484 	}
1485 
1486 	dev_deactivate_many(head);
1487 
1488 	list_for_each_entry(dev, head, close_list) {
1489 		const struct net_device_ops *ops = dev->netdev_ops;
1490 
1491 		/*
1492 		 *	Call the device specific close. This cannot fail.
1493 		 *	Only if device is UP
1494 		 *
1495 		 *	We allow it to be called even after a DETACH hot-plug
1496 		 *	event.
1497 		 */
1498 		if (ops->ndo_stop)
1499 			ops->ndo_stop(dev);
1500 
1501 		dev->flags &= ~IFF_UP;
1502 		netpoll_poll_enable(dev);
1503 	}
1504 }
1505 
1506 static void __dev_close(struct net_device *dev)
1507 {
1508 	LIST_HEAD(single);
1509 
1510 	list_add(&dev->close_list, &single);
1511 	__dev_close_many(&single);
1512 	list_del(&single);
1513 }
1514 
1515 void dev_close_many(struct list_head *head, bool unlink)
1516 {
1517 	struct net_device *dev, *tmp;
1518 
1519 	/* Remove the devices that don't need to be closed */
1520 	list_for_each_entry_safe(dev, tmp, head, close_list)
1521 		if (!(dev->flags & IFF_UP))
1522 			list_del_init(&dev->close_list);
1523 
1524 	__dev_close_many(head);
1525 
1526 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1527 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1528 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1529 		if (unlink)
1530 			list_del_init(&dev->close_list);
1531 	}
1532 }
1533 EXPORT_SYMBOL(dev_close_many);
1534 
1535 /**
1536  *	dev_close - shutdown an interface.
1537  *	@dev: device to shutdown
1538  *
1539  *	This function moves an active device into down state. A
1540  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1541  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1542  *	chain.
1543  */
1544 void dev_close(struct net_device *dev)
1545 {
1546 	if (dev->flags & IFF_UP) {
1547 		LIST_HEAD(single);
1548 
1549 		list_add(&dev->close_list, &single);
1550 		dev_close_many(&single, true);
1551 		list_del(&single);
1552 	}
1553 }
1554 EXPORT_SYMBOL(dev_close);
1555 
1556 
1557 /**
1558  *	dev_disable_lro - disable Large Receive Offload on a device
1559  *	@dev: device
1560  *
1561  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1562  *	called under RTNL.  This is needed if received packets may be
1563  *	forwarded to another interface.
1564  */
1565 void dev_disable_lro(struct net_device *dev)
1566 {
1567 	struct net_device *lower_dev;
1568 	struct list_head *iter;
1569 
1570 	dev->wanted_features &= ~NETIF_F_LRO;
1571 	netdev_update_features(dev);
1572 
1573 	if (unlikely(dev->features & NETIF_F_LRO))
1574 		netdev_WARN(dev, "failed to disable LRO!\n");
1575 
1576 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1577 		dev_disable_lro(lower_dev);
1578 }
1579 EXPORT_SYMBOL(dev_disable_lro);
1580 
1581 /**
1582  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1583  *	@dev: device
1584  *
1585  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1586  *	called under RTNL.  This is needed if Generic XDP is installed on
1587  *	the device.
1588  */
1589 static void dev_disable_gro_hw(struct net_device *dev)
1590 {
1591 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1592 	netdev_update_features(dev);
1593 
1594 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1595 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1596 }
1597 
1598 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1599 {
1600 #define N(val) 						\
1601 	case NETDEV_##val:				\
1602 		return "NETDEV_" __stringify(val);
1603 	switch (cmd) {
1604 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1605 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1606 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1607 	N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1608 	N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1609 	N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1610 	N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1611 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1612 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1613 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1614 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1615 	N(XDP_FEAT_CHANGE)
1616 	}
1617 #undef N
1618 	return "UNKNOWN_NETDEV_EVENT";
1619 }
1620 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1621 
1622 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1623 				   struct net_device *dev)
1624 {
1625 	struct netdev_notifier_info info = {
1626 		.dev = dev,
1627 	};
1628 
1629 	return nb->notifier_call(nb, val, &info);
1630 }
1631 
1632 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1633 					     struct net_device *dev)
1634 {
1635 	int err;
1636 
1637 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1638 	err = notifier_to_errno(err);
1639 	if (err)
1640 		return err;
1641 
1642 	if (!(dev->flags & IFF_UP))
1643 		return 0;
1644 
1645 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1646 	return 0;
1647 }
1648 
1649 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1650 						struct net_device *dev)
1651 {
1652 	if (dev->flags & IFF_UP) {
1653 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1654 					dev);
1655 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1656 	}
1657 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1658 }
1659 
1660 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1661 						 struct net *net)
1662 {
1663 	struct net_device *dev;
1664 	int err;
1665 
1666 	for_each_netdev(net, dev) {
1667 		err = call_netdevice_register_notifiers(nb, dev);
1668 		if (err)
1669 			goto rollback;
1670 	}
1671 	return 0;
1672 
1673 rollback:
1674 	for_each_netdev_continue_reverse(net, dev)
1675 		call_netdevice_unregister_notifiers(nb, dev);
1676 	return err;
1677 }
1678 
1679 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1680 						    struct net *net)
1681 {
1682 	struct net_device *dev;
1683 
1684 	for_each_netdev(net, dev)
1685 		call_netdevice_unregister_notifiers(nb, dev);
1686 }
1687 
1688 static int dev_boot_phase = 1;
1689 
1690 /**
1691  * register_netdevice_notifier - register a network notifier block
1692  * @nb: notifier
1693  *
1694  * Register a notifier to be called when network device events occur.
1695  * The notifier passed is linked into the kernel structures and must
1696  * not be reused until it has been unregistered. A negative errno code
1697  * is returned on a failure.
1698  *
1699  * When registered all registration and up events are replayed
1700  * to the new notifier to allow device to have a race free
1701  * view of the network device list.
1702  */
1703 
1704 int register_netdevice_notifier(struct notifier_block *nb)
1705 {
1706 	struct net *net;
1707 	int err;
1708 
1709 	/* Close race with setup_net() and cleanup_net() */
1710 	down_write(&pernet_ops_rwsem);
1711 	rtnl_lock();
1712 	err = raw_notifier_chain_register(&netdev_chain, nb);
1713 	if (err)
1714 		goto unlock;
1715 	if (dev_boot_phase)
1716 		goto unlock;
1717 	for_each_net(net) {
1718 		err = call_netdevice_register_net_notifiers(nb, net);
1719 		if (err)
1720 			goto rollback;
1721 	}
1722 
1723 unlock:
1724 	rtnl_unlock();
1725 	up_write(&pernet_ops_rwsem);
1726 	return err;
1727 
1728 rollback:
1729 	for_each_net_continue_reverse(net)
1730 		call_netdevice_unregister_net_notifiers(nb, net);
1731 
1732 	raw_notifier_chain_unregister(&netdev_chain, nb);
1733 	goto unlock;
1734 }
1735 EXPORT_SYMBOL(register_netdevice_notifier);
1736 
1737 /**
1738  * unregister_netdevice_notifier - unregister a network notifier block
1739  * @nb: notifier
1740  *
1741  * Unregister a notifier previously registered by
1742  * register_netdevice_notifier(). The notifier is unlinked into the
1743  * kernel structures and may then be reused. A negative errno code
1744  * is returned on a failure.
1745  *
1746  * After unregistering unregister and down device events are synthesized
1747  * for all devices on the device list to the removed notifier to remove
1748  * the need for special case cleanup code.
1749  */
1750 
1751 int unregister_netdevice_notifier(struct notifier_block *nb)
1752 {
1753 	struct net *net;
1754 	int err;
1755 
1756 	/* Close race with setup_net() and cleanup_net() */
1757 	down_write(&pernet_ops_rwsem);
1758 	rtnl_lock();
1759 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1760 	if (err)
1761 		goto unlock;
1762 
1763 	for_each_net(net)
1764 		call_netdevice_unregister_net_notifiers(nb, net);
1765 
1766 unlock:
1767 	rtnl_unlock();
1768 	up_write(&pernet_ops_rwsem);
1769 	return err;
1770 }
1771 EXPORT_SYMBOL(unregister_netdevice_notifier);
1772 
1773 static int __register_netdevice_notifier_net(struct net *net,
1774 					     struct notifier_block *nb,
1775 					     bool ignore_call_fail)
1776 {
1777 	int err;
1778 
1779 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1780 	if (err)
1781 		return err;
1782 	if (dev_boot_phase)
1783 		return 0;
1784 
1785 	err = call_netdevice_register_net_notifiers(nb, net);
1786 	if (err && !ignore_call_fail)
1787 		goto chain_unregister;
1788 
1789 	return 0;
1790 
1791 chain_unregister:
1792 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1793 	return err;
1794 }
1795 
1796 static int __unregister_netdevice_notifier_net(struct net *net,
1797 					       struct notifier_block *nb)
1798 {
1799 	int err;
1800 
1801 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1802 	if (err)
1803 		return err;
1804 
1805 	call_netdevice_unregister_net_notifiers(nb, net);
1806 	return 0;
1807 }
1808 
1809 /**
1810  * register_netdevice_notifier_net - register a per-netns network notifier block
1811  * @net: network namespace
1812  * @nb: notifier
1813  *
1814  * Register a notifier to be called when network device events occur.
1815  * The notifier passed is linked into the kernel structures and must
1816  * not be reused until it has been unregistered. A negative errno code
1817  * is returned on a failure.
1818  *
1819  * When registered all registration and up events are replayed
1820  * to the new notifier to allow device to have a race free
1821  * view of the network device list.
1822  */
1823 
1824 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1825 {
1826 	int err;
1827 
1828 	rtnl_lock();
1829 	err = __register_netdevice_notifier_net(net, nb, false);
1830 	rtnl_unlock();
1831 	return err;
1832 }
1833 EXPORT_SYMBOL(register_netdevice_notifier_net);
1834 
1835 /**
1836  * unregister_netdevice_notifier_net - unregister a per-netns
1837  *                                     network notifier block
1838  * @net: network namespace
1839  * @nb: notifier
1840  *
1841  * Unregister a notifier previously registered by
1842  * register_netdevice_notifier_net(). The notifier is unlinked from the
1843  * kernel structures and may then be reused. A negative errno code
1844  * is returned on a failure.
1845  *
1846  * After unregistering unregister and down device events are synthesized
1847  * for all devices on the device list to the removed notifier to remove
1848  * the need for special case cleanup code.
1849  */
1850 
1851 int unregister_netdevice_notifier_net(struct net *net,
1852 				      struct notifier_block *nb)
1853 {
1854 	int err;
1855 
1856 	rtnl_lock();
1857 	err = __unregister_netdevice_notifier_net(net, nb);
1858 	rtnl_unlock();
1859 	return err;
1860 }
1861 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1862 
1863 static void __move_netdevice_notifier_net(struct net *src_net,
1864 					  struct net *dst_net,
1865 					  struct notifier_block *nb)
1866 {
1867 	__unregister_netdevice_notifier_net(src_net, nb);
1868 	__register_netdevice_notifier_net(dst_net, nb, true);
1869 }
1870 
1871 int register_netdevice_notifier_dev_net(struct net_device *dev,
1872 					struct notifier_block *nb,
1873 					struct netdev_net_notifier *nn)
1874 {
1875 	int err;
1876 
1877 	rtnl_lock();
1878 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1879 	if (!err) {
1880 		nn->nb = nb;
1881 		list_add(&nn->list, &dev->net_notifier_list);
1882 	}
1883 	rtnl_unlock();
1884 	return err;
1885 }
1886 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1887 
1888 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1889 					  struct notifier_block *nb,
1890 					  struct netdev_net_notifier *nn)
1891 {
1892 	int err;
1893 
1894 	rtnl_lock();
1895 	list_del(&nn->list);
1896 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1897 	rtnl_unlock();
1898 	return err;
1899 }
1900 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1901 
1902 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1903 					     struct net *net)
1904 {
1905 	struct netdev_net_notifier *nn;
1906 
1907 	list_for_each_entry(nn, &dev->net_notifier_list, list)
1908 		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1909 }
1910 
1911 /**
1912  *	call_netdevice_notifiers_info - call all network notifier blocks
1913  *	@val: value passed unmodified to notifier function
1914  *	@info: notifier information data
1915  *
1916  *	Call all network notifier blocks.  Parameters and return value
1917  *	are as for raw_notifier_call_chain().
1918  */
1919 
1920 int call_netdevice_notifiers_info(unsigned long val,
1921 				  struct netdev_notifier_info *info)
1922 {
1923 	struct net *net = dev_net(info->dev);
1924 	int ret;
1925 
1926 	ASSERT_RTNL();
1927 
1928 	/* Run per-netns notifier block chain first, then run the global one.
1929 	 * Hopefully, one day, the global one is going to be removed after
1930 	 * all notifier block registrators get converted to be per-netns.
1931 	 */
1932 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1933 	if (ret & NOTIFY_STOP_MASK)
1934 		return ret;
1935 	return raw_notifier_call_chain(&netdev_chain, val, info);
1936 }
1937 
1938 /**
1939  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1940  *	                                       for and rollback on error
1941  *	@val_up: value passed unmodified to notifier function
1942  *	@val_down: value passed unmodified to the notifier function when
1943  *	           recovering from an error on @val_up
1944  *	@info: notifier information data
1945  *
1946  *	Call all per-netns network notifier blocks, but not notifier blocks on
1947  *	the global notifier chain. Parameters and return value are as for
1948  *	raw_notifier_call_chain_robust().
1949  */
1950 
1951 static int
1952 call_netdevice_notifiers_info_robust(unsigned long val_up,
1953 				     unsigned long val_down,
1954 				     struct netdev_notifier_info *info)
1955 {
1956 	struct net *net = dev_net(info->dev);
1957 
1958 	ASSERT_RTNL();
1959 
1960 	return raw_notifier_call_chain_robust(&net->netdev_chain,
1961 					      val_up, val_down, info);
1962 }
1963 
1964 static int call_netdevice_notifiers_extack(unsigned long val,
1965 					   struct net_device *dev,
1966 					   struct netlink_ext_ack *extack)
1967 {
1968 	struct netdev_notifier_info info = {
1969 		.dev = dev,
1970 		.extack = extack,
1971 	};
1972 
1973 	return call_netdevice_notifiers_info(val, &info);
1974 }
1975 
1976 /**
1977  *	call_netdevice_notifiers - call all network notifier blocks
1978  *      @val: value passed unmodified to notifier function
1979  *      @dev: net_device pointer passed unmodified to notifier function
1980  *
1981  *	Call all network notifier blocks.  Parameters and return value
1982  *	are as for raw_notifier_call_chain().
1983  */
1984 
1985 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1986 {
1987 	return call_netdevice_notifiers_extack(val, dev, NULL);
1988 }
1989 EXPORT_SYMBOL(call_netdevice_notifiers);
1990 
1991 /**
1992  *	call_netdevice_notifiers_mtu - call all network notifier blocks
1993  *	@val: value passed unmodified to notifier function
1994  *	@dev: net_device pointer passed unmodified to notifier function
1995  *	@arg: additional u32 argument passed to the notifier function
1996  *
1997  *	Call all network notifier blocks.  Parameters and return value
1998  *	are as for raw_notifier_call_chain().
1999  */
2000 static int call_netdevice_notifiers_mtu(unsigned long val,
2001 					struct net_device *dev, u32 arg)
2002 {
2003 	struct netdev_notifier_info_ext info = {
2004 		.info.dev = dev,
2005 		.ext.mtu = arg,
2006 	};
2007 
2008 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2009 
2010 	return call_netdevice_notifiers_info(val, &info.info);
2011 }
2012 
2013 #ifdef CONFIG_NET_INGRESS
2014 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2015 
2016 void net_inc_ingress_queue(void)
2017 {
2018 	static_branch_inc(&ingress_needed_key);
2019 }
2020 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2021 
2022 void net_dec_ingress_queue(void)
2023 {
2024 	static_branch_dec(&ingress_needed_key);
2025 }
2026 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2027 #endif
2028 
2029 #ifdef CONFIG_NET_EGRESS
2030 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2031 
2032 void net_inc_egress_queue(void)
2033 {
2034 	static_branch_inc(&egress_needed_key);
2035 }
2036 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2037 
2038 void net_dec_egress_queue(void)
2039 {
2040 	static_branch_dec(&egress_needed_key);
2041 }
2042 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2043 #endif
2044 
2045 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2046 EXPORT_SYMBOL(netstamp_needed_key);
2047 #ifdef CONFIG_JUMP_LABEL
2048 static atomic_t netstamp_needed_deferred;
2049 static atomic_t netstamp_wanted;
2050 static void netstamp_clear(struct work_struct *work)
2051 {
2052 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2053 	int wanted;
2054 
2055 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2056 	if (wanted > 0)
2057 		static_branch_enable(&netstamp_needed_key);
2058 	else
2059 		static_branch_disable(&netstamp_needed_key);
2060 }
2061 static DECLARE_WORK(netstamp_work, netstamp_clear);
2062 #endif
2063 
2064 void net_enable_timestamp(void)
2065 {
2066 #ifdef CONFIG_JUMP_LABEL
2067 	int wanted = atomic_read(&netstamp_wanted);
2068 
2069 	while (wanted > 0) {
2070 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2071 			return;
2072 	}
2073 	atomic_inc(&netstamp_needed_deferred);
2074 	schedule_work(&netstamp_work);
2075 #else
2076 	static_branch_inc(&netstamp_needed_key);
2077 #endif
2078 }
2079 EXPORT_SYMBOL(net_enable_timestamp);
2080 
2081 void net_disable_timestamp(void)
2082 {
2083 #ifdef CONFIG_JUMP_LABEL
2084 	int wanted = atomic_read(&netstamp_wanted);
2085 
2086 	while (wanted > 1) {
2087 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2088 			return;
2089 	}
2090 	atomic_dec(&netstamp_needed_deferred);
2091 	schedule_work(&netstamp_work);
2092 #else
2093 	static_branch_dec(&netstamp_needed_key);
2094 #endif
2095 }
2096 EXPORT_SYMBOL(net_disable_timestamp);
2097 
2098 static inline void net_timestamp_set(struct sk_buff *skb)
2099 {
2100 	skb->tstamp = 0;
2101 	skb->mono_delivery_time = 0;
2102 	if (static_branch_unlikely(&netstamp_needed_key))
2103 		skb->tstamp = ktime_get_real();
2104 }
2105 
2106 #define net_timestamp_check(COND, SKB)				\
2107 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2108 		if ((COND) && !(SKB)->tstamp)			\
2109 			(SKB)->tstamp = ktime_get_real();	\
2110 	}							\
2111 
2112 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2113 {
2114 	return __is_skb_forwardable(dev, skb, true);
2115 }
2116 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2117 
2118 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2119 			      bool check_mtu)
2120 {
2121 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2122 
2123 	if (likely(!ret)) {
2124 		skb->protocol = eth_type_trans(skb, dev);
2125 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2126 	}
2127 
2128 	return ret;
2129 }
2130 
2131 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2132 {
2133 	return __dev_forward_skb2(dev, skb, true);
2134 }
2135 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2136 
2137 /**
2138  * dev_forward_skb - loopback an skb to another netif
2139  *
2140  * @dev: destination network device
2141  * @skb: buffer to forward
2142  *
2143  * return values:
2144  *	NET_RX_SUCCESS	(no congestion)
2145  *	NET_RX_DROP     (packet was dropped, but freed)
2146  *
2147  * dev_forward_skb can be used for injecting an skb from the
2148  * start_xmit function of one device into the receive queue
2149  * of another device.
2150  *
2151  * The receiving device may be in another namespace, so
2152  * we have to clear all information in the skb that could
2153  * impact namespace isolation.
2154  */
2155 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2156 {
2157 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2158 }
2159 EXPORT_SYMBOL_GPL(dev_forward_skb);
2160 
2161 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2162 {
2163 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2164 }
2165 
2166 static inline int deliver_skb(struct sk_buff *skb,
2167 			      struct packet_type *pt_prev,
2168 			      struct net_device *orig_dev)
2169 {
2170 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2171 		return -ENOMEM;
2172 	refcount_inc(&skb->users);
2173 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2174 }
2175 
2176 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2177 					  struct packet_type **pt,
2178 					  struct net_device *orig_dev,
2179 					  __be16 type,
2180 					  struct list_head *ptype_list)
2181 {
2182 	struct packet_type *ptype, *pt_prev = *pt;
2183 
2184 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2185 		if (ptype->type != type)
2186 			continue;
2187 		if (pt_prev)
2188 			deliver_skb(skb, pt_prev, orig_dev);
2189 		pt_prev = ptype;
2190 	}
2191 	*pt = pt_prev;
2192 }
2193 
2194 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2195 {
2196 	if (!ptype->af_packet_priv || !skb->sk)
2197 		return false;
2198 
2199 	if (ptype->id_match)
2200 		return ptype->id_match(ptype, skb->sk);
2201 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2202 		return true;
2203 
2204 	return false;
2205 }
2206 
2207 /**
2208  * dev_nit_active - return true if any network interface taps are in use
2209  *
2210  * @dev: network device to check for the presence of taps
2211  */
2212 bool dev_nit_active(struct net_device *dev)
2213 {
2214 	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2215 }
2216 EXPORT_SYMBOL_GPL(dev_nit_active);
2217 
2218 /*
2219  *	Support routine. Sends outgoing frames to any network
2220  *	taps currently in use.
2221  */
2222 
2223 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2224 {
2225 	struct packet_type *ptype;
2226 	struct sk_buff *skb2 = NULL;
2227 	struct packet_type *pt_prev = NULL;
2228 	struct list_head *ptype_list = &ptype_all;
2229 
2230 	rcu_read_lock();
2231 again:
2232 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2233 		if (ptype->ignore_outgoing)
2234 			continue;
2235 
2236 		/* Never send packets back to the socket
2237 		 * they originated from - MvS (miquels@drinkel.ow.org)
2238 		 */
2239 		if (skb_loop_sk(ptype, skb))
2240 			continue;
2241 
2242 		if (pt_prev) {
2243 			deliver_skb(skb2, pt_prev, skb->dev);
2244 			pt_prev = ptype;
2245 			continue;
2246 		}
2247 
2248 		/* need to clone skb, done only once */
2249 		skb2 = skb_clone(skb, GFP_ATOMIC);
2250 		if (!skb2)
2251 			goto out_unlock;
2252 
2253 		net_timestamp_set(skb2);
2254 
2255 		/* skb->nh should be correctly
2256 		 * set by sender, so that the second statement is
2257 		 * just protection against buggy protocols.
2258 		 */
2259 		skb_reset_mac_header(skb2);
2260 
2261 		if (skb_network_header(skb2) < skb2->data ||
2262 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2263 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2264 					     ntohs(skb2->protocol),
2265 					     dev->name);
2266 			skb_reset_network_header(skb2);
2267 		}
2268 
2269 		skb2->transport_header = skb2->network_header;
2270 		skb2->pkt_type = PACKET_OUTGOING;
2271 		pt_prev = ptype;
2272 	}
2273 
2274 	if (ptype_list == &ptype_all) {
2275 		ptype_list = &dev->ptype_all;
2276 		goto again;
2277 	}
2278 out_unlock:
2279 	if (pt_prev) {
2280 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2281 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2282 		else
2283 			kfree_skb(skb2);
2284 	}
2285 	rcu_read_unlock();
2286 }
2287 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2288 
2289 /**
2290  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2291  * @dev: Network device
2292  * @txq: number of queues available
2293  *
2294  * If real_num_tx_queues is changed the tc mappings may no longer be
2295  * valid. To resolve this verify the tc mapping remains valid and if
2296  * not NULL the mapping. With no priorities mapping to this
2297  * offset/count pair it will no longer be used. In the worst case TC0
2298  * is invalid nothing can be done so disable priority mappings. If is
2299  * expected that drivers will fix this mapping if they can before
2300  * calling netif_set_real_num_tx_queues.
2301  */
2302 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2303 {
2304 	int i;
2305 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2306 
2307 	/* If TC0 is invalidated disable TC mapping */
2308 	if (tc->offset + tc->count > txq) {
2309 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2310 		dev->num_tc = 0;
2311 		return;
2312 	}
2313 
2314 	/* Invalidated prio to tc mappings set to TC0 */
2315 	for (i = 1; i < TC_BITMASK + 1; i++) {
2316 		int q = netdev_get_prio_tc_map(dev, i);
2317 
2318 		tc = &dev->tc_to_txq[q];
2319 		if (tc->offset + tc->count > txq) {
2320 			netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2321 				    i, q);
2322 			netdev_set_prio_tc_map(dev, i, 0);
2323 		}
2324 	}
2325 }
2326 
2327 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2328 {
2329 	if (dev->num_tc) {
2330 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2331 		int i;
2332 
2333 		/* walk through the TCs and see if it falls into any of them */
2334 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2335 			if ((txq - tc->offset) < tc->count)
2336 				return i;
2337 		}
2338 
2339 		/* didn't find it, just return -1 to indicate no match */
2340 		return -1;
2341 	}
2342 
2343 	return 0;
2344 }
2345 EXPORT_SYMBOL(netdev_txq_to_tc);
2346 
2347 #ifdef CONFIG_XPS
2348 static struct static_key xps_needed __read_mostly;
2349 static struct static_key xps_rxqs_needed __read_mostly;
2350 static DEFINE_MUTEX(xps_map_mutex);
2351 #define xmap_dereference(P)		\
2352 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2353 
2354 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2355 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2356 {
2357 	struct xps_map *map = NULL;
2358 	int pos;
2359 
2360 	if (dev_maps)
2361 		map = xmap_dereference(dev_maps->attr_map[tci]);
2362 	if (!map)
2363 		return false;
2364 
2365 	for (pos = map->len; pos--;) {
2366 		if (map->queues[pos] != index)
2367 			continue;
2368 
2369 		if (map->len > 1) {
2370 			map->queues[pos] = map->queues[--map->len];
2371 			break;
2372 		}
2373 
2374 		if (old_maps)
2375 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2376 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2377 		kfree_rcu(map, rcu);
2378 		return false;
2379 	}
2380 
2381 	return true;
2382 }
2383 
2384 static bool remove_xps_queue_cpu(struct net_device *dev,
2385 				 struct xps_dev_maps *dev_maps,
2386 				 int cpu, u16 offset, u16 count)
2387 {
2388 	int num_tc = dev_maps->num_tc;
2389 	bool active = false;
2390 	int tci;
2391 
2392 	for (tci = cpu * num_tc; num_tc--; tci++) {
2393 		int i, j;
2394 
2395 		for (i = count, j = offset; i--; j++) {
2396 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2397 				break;
2398 		}
2399 
2400 		active |= i < 0;
2401 	}
2402 
2403 	return active;
2404 }
2405 
2406 static void reset_xps_maps(struct net_device *dev,
2407 			   struct xps_dev_maps *dev_maps,
2408 			   enum xps_map_type type)
2409 {
2410 	static_key_slow_dec_cpuslocked(&xps_needed);
2411 	if (type == XPS_RXQS)
2412 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2413 
2414 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2415 
2416 	kfree_rcu(dev_maps, rcu);
2417 }
2418 
2419 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2420 			   u16 offset, u16 count)
2421 {
2422 	struct xps_dev_maps *dev_maps;
2423 	bool active = false;
2424 	int i, j;
2425 
2426 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2427 	if (!dev_maps)
2428 		return;
2429 
2430 	for (j = 0; j < dev_maps->nr_ids; j++)
2431 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2432 	if (!active)
2433 		reset_xps_maps(dev, dev_maps, type);
2434 
2435 	if (type == XPS_CPUS) {
2436 		for (i = offset + (count - 1); count--; i--)
2437 			netdev_queue_numa_node_write(
2438 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2439 	}
2440 }
2441 
2442 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2443 				   u16 count)
2444 {
2445 	if (!static_key_false(&xps_needed))
2446 		return;
2447 
2448 	cpus_read_lock();
2449 	mutex_lock(&xps_map_mutex);
2450 
2451 	if (static_key_false(&xps_rxqs_needed))
2452 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2453 
2454 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2455 
2456 	mutex_unlock(&xps_map_mutex);
2457 	cpus_read_unlock();
2458 }
2459 
2460 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2461 {
2462 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2463 }
2464 
2465 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2466 				      u16 index, bool is_rxqs_map)
2467 {
2468 	struct xps_map *new_map;
2469 	int alloc_len = XPS_MIN_MAP_ALLOC;
2470 	int i, pos;
2471 
2472 	for (pos = 0; map && pos < map->len; pos++) {
2473 		if (map->queues[pos] != index)
2474 			continue;
2475 		return map;
2476 	}
2477 
2478 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2479 	if (map) {
2480 		if (pos < map->alloc_len)
2481 			return map;
2482 
2483 		alloc_len = map->alloc_len * 2;
2484 	}
2485 
2486 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2487 	 *  map
2488 	 */
2489 	if (is_rxqs_map)
2490 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2491 	else
2492 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2493 				       cpu_to_node(attr_index));
2494 	if (!new_map)
2495 		return NULL;
2496 
2497 	for (i = 0; i < pos; i++)
2498 		new_map->queues[i] = map->queues[i];
2499 	new_map->alloc_len = alloc_len;
2500 	new_map->len = pos;
2501 
2502 	return new_map;
2503 }
2504 
2505 /* Copy xps maps at a given index */
2506 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2507 			      struct xps_dev_maps *new_dev_maps, int index,
2508 			      int tc, bool skip_tc)
2509 {
2510 	int i, tci = index * dev_maps->num_tc;
2511 	struct xps_map *map;
2512 
2513 	/* copy maps belonging to foreign traffic classes */
2514 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2515 		if (i == tc && skip_tc)
2516 			continue;
2517 
2518 		/* fill in the new device map from the old device map */
2519 		map = xmap_dereference(dev_maps->attr_map[tci]);
2520 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2521 	}
2522 }
2523 
2524 /* Must be called under cpus_read_lock */
2525 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2526 			  u16 index, enum xps_map_type type)
2527 {
2528 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2529 	const unsigned long *online_mask = NULL;
2530 	bool active = false, copy = false;
2531 	int i, j, tci, numa_node_id = -2;
2532 	int maps_sz, num_tc = 1, tc = 0;
2533 	struct xps_map *map, *new_map;
2534 	unsigned int nr_ids;
2535 
2536 	WARN_ON_ONCE(index >= dev->num_tx_queues);
2537 
2538 	if (dev->num_tc) {
2539 		/* Do not allow XPS on subordinate device directly */
2540 		num_tc = dev->num_tc;
2541 		if (num_tc < 0)
2542 			return -EINVAL;
2543 
2544 		/* If queue belongs to subordinate dev use its map */
2545 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2546 
2547 		tc = netdev_txq_to_tc(dev, index);
2548 		if (tc < 0)
2549 			return -EINVAL;
2550 	}
2551 
2552 	mutex_lock(&xps_map_mutex);
2553 
2554 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2555 	if (type == XPS_RXQS) {
2556 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2557 		nr_ids = dev->num_rx_queues;
2558 	} else {
2559 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2560 		if (num_possible_cpus() > 1)
2561 			online_mask = cpumask_bits(cpu_online_mask);
2562 		nr_ids = nr_cpu_ids;
2563 	}
2564 
2565 	if (maps_sz < L1_CACHE_BYTES)
2566 		maps_sz = L1_CACHE_BYTES;
2567 
2568 	/* The old dev_maps could be larger or smaller than the one we're
2569 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2570 	 * between. We could try to be smart, but let's be safe instead and only
2571 	 * copy foreign traffic classes if the two map sizes match.
2572 	 */
2573 	if (dev_maps &&
2574 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2575 		copy = true;
2576 
2577 	/* allocate memory for queue storage */
2578 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2579 	     j < nr_ids;) {
2580 		if (!new_dev_maps) {
2581 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2582 			if (!new_dev_maps) {
2583 				mutex_unlock(&xps_map_mutex);
2584 				return -ENOMEM;
2585 			}
2586 
2587 			new_dev_maps->nr_ids = nr_ids;
2588 			new_dev_maps->num_tc = num_tc;
2589 		}
2590 
2591 		tci = j * num_tc + tc;
2592 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2593 
2594 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2595 		if (!map)
2596 			goto error;
2597 
2598 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2599 	}
2600 
2601 	if (!new_dev_maps)
2602 		goto out_no_new_maps;
2603 
2604 	if (!dev_maps) {
2605 		/* Increment static keys at most once per type */
2606 		static_key_slow_inc_cpuslocked(&xps_needed);
2607 		if (type == XPS_RXQS)
2608 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2609 	}
2610 
2611 	for (j = 0; j < nr_ids; j++) {
2612 		bool skip_tc = false;
2613 
2614 		tci = j * num_tc + tc;
2615 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2616 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2617 			/* add tx-queue to CPU/rx-queue maps */
2618 			int pos = 0;
2619 
2620 			skip_tc = true;
2621 
2622 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2623 			while ((pos < map->len) && (map->queues[pos] != index))
2624 				pos++;
2625 
2626 			if (pos == map->len)
2627 				map->queues[map->len++] = index;
2628 #ifdef CONFIG_NUMA
2629 			if (type == XPS_CPUS) {
2630 				if (numa_node_id == -2)
2631 					numa_node_id = cpu_to_node(j);
2632 				else if (numa_node_id != cpu_to_node(j))
2633 					numa_node_id = -1;
2634 			}
2635 #endif
2636 		}
2637 
2638 		if (copy)
2639 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2640 					  skip_tc);
2641 	}
2642 
2643 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2644 
2645 	/* Cleanup old maps */
2646 	if (!dev_maps)
2647 		goto out_no_old_maps;
2648 
2649 	for (j = 0; j < dev_maps->nr_ids; j++) {
2650 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2651 			map = xmap_dereference(dev_maps->attr_map[tci]);
2652 			if (!map)
2653 				continue;
2654 
2655 			if (copy) {
2656 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2657 				if (map == new_map)
2658 					continue;
2659 			}
2660 
2661 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2662 			kfree_rcu(map, rcu);
2663 		}
2664 	}
2665 
2666 	old_dev_maps = dev_maps;
2667 
2668 out_no_old_maps:
2669 	dev_maps = new_dev_maps;
2670 	active = true;
2671 
2672 out_no_new_maps:
2673 	if (type == XPS_CPUS)
2674 		/* update Tx queue numa node */
2675 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2676 					     (numa_node_id >= 0) ?
2677 					     numa_node_id : NUMA_NO_NODE);
2678 
2679 	if (!dev_maps)
2680 		goto out_no_maps;
2681 
2682 	/* removes tx-queue from unused CPUs/rx-queues */
2683 	for (j = 0; j < dev_maps->nr_ids; j++) {
2684 		tci = j * dev_maps->num_tc;
2685 
2686 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2687 			if (i == tc &&
2688 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2689 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2690 				continue;
2691 
2692 			active |= remove_xps_queue(dev_maps,
2693 						   copy ? old_dev_maps : NULL,
2694 						   tci, index);
2695 		}
2696 	}
2697 
2698 	if (old_dev_maps)
2699 		kfree_rcu(old_dev_maps, rcu);
2700 
2701 	/* free map if not active */
2702 	if (!active)
2703 		reset_xps_maps(dev, dev_maps, type);
2704 
2705 out_no_maps:
2706 	mutex_unlock(&xps_map_mutex);
2707 
2708 	return 0;
2709 error:
2710 	/* remove any maps that we added */
2711 	for (j = 0; j < nr_ids; j++) {
2712 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2713 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2714 			map = copy ?
2715 			      xmap_dereference(dev_maps->attr_map[tci]) :
2716 			      NULL;
2717 			if (new_map && new_map != map)
2718 				kfree(new_map);
2719 		}
2720 	}
2721 
2722 	mutex_unlock(&xps_map_mutex);
2723 
2724 	kfree(new_dev_maps);
2725 	return -ENOMEM;
2726 }
2727 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2728 
2729 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2730 			u16 index)
2731 {
2732 	int ret;
2733 
2734 	cpus_read_lock();
2735 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2736 	cpus_read_unlock();
2737 
2738 	return ret;
2739 }
2740 EXPORT_SYMBOL(netif_set_xps_queue);
2741 
2742 #endif
2743 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2744 {
2745 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2746 
2747 	/* Unbind any subordinate channels */
2748 	while (txq-- != &dev->_tx[0]) {
2749 		if (txq->sb_dev)
2750 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2751 	}
2752 }
2753 
2754 void netdev_reset_tc(struct net_device *dev)
2755 {
2756 #ifdef CONFIG_XPS
2757 	netif_reset_xps_queues_gt(dev, 0);
2758 #endif
2759 	netdev_unbind_all_sb_channels(dev);
2760 
2761 	/* Reset TC configuration of device */
2762 	dev->num_tc = 0;
2763 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2764 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2765 }
2766 EXPORT_SYMBOL(netdev_reset_tc);
2767 
2768 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2769 {
2770 	if (tc >= dev->num_tc)
2771 		return -EINVAL;
2772 
2773 #ifdef CONFIG_XPS
2774 	netif_reset_xps_queues(dev, offset, count);
2775 #endif
2776 	dev->tc_to_txq[tc].count = count;
2777 	dev->tc_to_txq[tc].offset = offset;
2778 	return 0;
2779 }
2780 EXPORT_SYMBOL(netdev_set_tc_queue);
2781 
2782 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2783 {
2784 	if (num_tc > TC_MAX_QUEUE)
2785 		return -EINVAL;
2786 
2787 #ifdef CONFIG_XPS
2788 	netif_reset_xps_queues_gt(dev, 0);
2789 #endif
2790 	netdev_unbind_all_sb_channels(dev);
2791 
2792 	dev->num_tc = num_tc;
2793 	return 0;
2794 }
2795 EXPORT_SYMBOL(netdev_set_num_tc);
2796 
2797 void netdev_unbind_sb_channel(struct net_device *dev,
2798 			      struct net_device *sb_dev)
2799 {
2800 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2801 
2802 #ifdef CONFIG_XPS
2803 	netif_reset_xps_queues_gt(sb_dev, 0);
2804 #endif
2805 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2806 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2807 
2808 	while (txq-- != &dev->_tx[0]) {
2809 		if (txq->sb_dev == sb_dev)
2810 			txq->sb_dev = NULL;
2811 	}
2812 }
2813 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2814 
2815 int netdev_bind_sb_channel_queue(struct net_device *dev,
2816 				 struct net_device *sb_dev,
2817 				 u8 tc, u16 count, u16 offset)
2818 {
2819 	/* Make certain the sb_dev and dev are already configured */
2820 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2821 		return -EINVAL;
2822 
2823 	/* We cannot hand out queues we don't have */
2824 	if ((offset + count) > dev->real_num_tx_queues)
2825 		return -EINVAL;
2826 
2827 	/* Record the mapping */
2828 	sb_dev->tc_to_txq[tc].count = count;
2829 	sb_dev->tc_to_txq[tc].offset = offset;
2830 
2831 	/* Provide a way for Tx queue to find the tc_to_txq map or
2832 	 * XPS map for itself.
2833 	 */
2834 	while (count--)
2835 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2836 
2837 	return 0;
2838 }
2839 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2840 
2841 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2842 {
2843 	/* Do not use a multiqueue device to represent a subordinate channel */
2844 	if (netif_is_multiqueue(dev))
2845 		return -ENODEV;
2846 
2847 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2848 	 * Channel 0 is meant to be "native" mode and used only to represent
2849 	 * the main root device. We allow writing 0 to reset the device back
2850 	 * to normal mode after being used as a subordinate channel.
2851 	 */
2852 	if (channel > S16_MAX)
2853 		return -EINVAL;
2854 
2855 	dev->num_tc = -channel;
2856 
2857 	return 0;
2858 }
2859 EXPORT_SYMBOL(netdev_set_sb_channel);
2860 
2861 /*
2862  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2863  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2864  */
2865 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2866 {
2867 	bool disabling;
2868 	int rc;
2869 
2870 	disabling = txq < dev->real_num_tx_queues;
2871 
2872 	if (txq < 1 || txq > dev->num_tx_queues)
2873 		return -EINVAL;
2874 
2875 	if (dev->reg_state == NETREG_REGISTERED ||
2876 	    dev->reg_state == NETREG_UNREGISTERING) {
2877 		ASSERT_RTNL();
2878 
2879 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2880 						  txq);
2881 		if (rc)
2882 			return rc;
2883 
2884 		if (dev->num_tc)
2885 			netif_setup_tc(dev, txq);
2886 
2887 		dev_qdisc_change_real_num_tx(dev, txq);
2888 
2889 		dev->real_num_tx_queues = txq;
2890 
2891 		if (disabling) {
2892 			synchronize_net();
2893 			qdisc_reset_all_tx_gt(dev, txq);
2894 #ifdef CONFIG_XPS
2895 			netif_reset_xps_queues_gt(dev, txq);
2896 #endif
2897 		}
2898 	} else {
2899 		dev->real_num_tx_queues = txq;
2900 	}
2901 
2902 	return 0;
2903 }
2904 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2905 
2906 #ifdef CONFIG_SYSFS
2907 /**
2908  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2909  *	@dev: Network device
2910  *	@rxq: Actual number of RX queues
2911  *
2912  *	This must be called either with the rtnl_lock held or before
2913  *	registration of the net device.  Returns 0 on success, or a
2914  *	negative error code.  If called before registration, it always
2915  *	succeeds.
2916  */
2917 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2918 {
2919 	int rc;
2920 
2921 	if (rxq < 1 || rxq > dev->num_rx_queues)
2922 		return -EINVAL;
2923 
2924 	if (dev->reg_state == NETREG_REGISTERED) {
2925 		ASSERT_RTNL();
2926 
2927 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2928 						  rxq);
2929 		if (rc)
2930 			return rc;
2931 	}
2932 
2933 	dev->real_num_rx_queues = rxq;
2934 	return 0;
2935 }
2936 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2937 #endif
2938 
2939 /**
2940  *	netif_set_real_num_queues - set actual number of RX and TX queues used
2941  *	@dev: Network device
2942  *	@txq: Actual number of TX queues
2943  *	@rxq: Actual number of RX queues
2944  *
2945  *	Set the real number of both TX and RX queues.
2946  *	Does nothing if the number of queues is already correct.
2947  */
2948 int netif_set_real_num_queues(struct net_device *dev,
2949 			      unsigned int txq, unsigned int rxq)
2950 {
2951 	unsigned int old_rxq = dev->real_num_rx_queues;
2952 	int err;
2953 
2954 	if (txq < 1 || txq > dev->num_tx_queues ||
2955 	    rxq < 1 || rxq > dev->num_rx_queues)
2956 		return -EINVAL;
2957 
2958 	/* Start from increases, so the error path only does decreases -
2959 	 * decreases can't fail.
2960 	 */
2961 	if (rxq > dev->real_num_rx_queues) {
2962 		err = netif_set_real_num_rx_queues(dev, rxq);
2963 		if (err)
2964 			return err;
2965 	}
2966 	if (txq > dev->real_num_tx_queues) {
2967 		err = netif_set_real_num_tx_queues(dev, txq);
2968 		if (err)
2969 			goto undo_rx;
2970 	}
2971 	if (rxq < dev->real_num_rx_queues)
2972 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
2973 	if (txq < dev->real_num_tx_queues)
2974 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
2975 
2976 	return 0;
2977 undo_rx:
2978 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
2979 	return err;
2980 }
2981 EXPORT_SYMBOL(netif_set_real_num_queues);
2982 
2983 /**
2984  * netif_set_tso_max_size() - set the max size of TSO frames supported
2985  * @dev:	netdev to update
2986  * @size:	max skb->len of a TSO frame
2987  *
2988  * Set the limit on the size of TSO super-frames the device can handle.
2989  * Unless explicitly set the stack will assume the value of
2990  * %GSO_LEGACY_MAX_SIZE.
2991  */
2992 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
2993 {
2994 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
2995 	if (size < READ_ONCE(dev->gso_max_size))
2996 		netif_set_gso_max_size(dev, size);
2997 	if (size < READ_ONCE(dev->gso_ipv4_max_size))
2998 		netif_set_gso_ipv4_max_size(dev, size);
2999 }
3000 EXPORT_SYMBOL(netif_set_tso_max_size);
3001 
3002 /**
3003  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3004  * @dev:	netdev to update
3005  * @segs:	max number of TCP segments
3006  *
3007  * Set the limit on the number of TCP segments the device can generate from
3008  * a single TSO super-frame.
3009  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3010  */
3011 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3012 {
3013 	dev->tso_max_segs = segs;
3014 	if (segs < READ_ONCE(dev->gso_max_segs))
3015 		netif_set_gso_max_segs(dev, segs);
3016 }
3017 EXPORT_SYMBOL(netif_set_tso_max_segs);
3018 
3019 /**
3020  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3021  * @to:		netdev to update
3022  * @from:	netdev from which to copy the limits
3023  */
3024 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3025 {
3026 	netif_set_tso_max_size(to, from->tso_max_size);
3027 	netif_set_tso_max_segs(to, from->tso_max_segs);
3028 }
3029 EXPORT_SYMBOL(netif_inherit_tso_max);
3030 
3031 /**
3032  * netif_get_num_default_rss_queues - default number of RSS queues
3033  *
3034  * Default value is the number of physical cores if there are only 1 or 2, or
3035  * divided by 2 if there are more.
3036  */
3037 int netif_get_num_default_rss_queues(void)
3038 {
3039 	cpumask_var_t cpus;
3040 	int cpu, count = 0;
3041 
3042 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3043 		return 1;
3044 
3045 	cpumask_copy(cpus, cpu_online_mask);
3046 	for_each_cpu(cpu, cpus) {
3047 		++count;
3048 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3049 	}
3050 	free_cpumask_var(cpus);
3051 
3052 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3053 }
3054 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3055 
3056 static void __netif_reschedule(struct Qdisc *q)
3057 {
3058 	struct softnet_data *sd;
3059 	unsigned long flags;
3060 
3061 	local_irq_save(flags);
3062 	sd = this_cpu_ptr(&softnet_data);
3063 	q->next_sched = NULL;
3064 	*sd->output_queue_tailp = q;
3065 	sd->output_queue_tailp = &q->next_sched;
3066 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3067 	local_irq_restore(flags);
3068 }
3069 
3070 void __netif_schedule(struct Qdisc *q)
3071 {
3072 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3073 		__netif_reschedule(q);
3074 }
3075 EXPORT_SYMBOL(__netif_schedule);
3076 
3077 struct dev_kfree_skb_cb {
3078 	enum skb_drop_reason reason;
3079 };
3080 
3081 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3082 {
3083 	return (struct dev_kfree_skb_cb *)skb->cb;
3084 }
3085 
3086 void netif_schedule_queue(struct netdev_queue *txq)
3087 {
3088 	rcu_read_lock();
3089 	if (!netif_xmit_stopped(txq)) {
3090 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3091 
3092 		__netif_schedule(q);
3093 	}
3094 	rcu_read_unlock();
3095 }
3096 EXPORT_SYMBOL(netif_schedule_queue);
3097 
3098 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3099 {
3100 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3101 		struct Qdisc *q;
3102 
3103 		rcu_read_lock();
3104 		q = rcu_dereference(dev_queue->qdisc);
3105 		__netif_schedule(q);
3106 		rcu_read_unlock();
3107 	}
3108 }
3109 EXPORT_SYMBOL(netif_tx_wake_queue);
3110 
3111 void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3112 {
3113 	unsigned long flags;
3114 
3115 	if (unlikely(!skb))
3116 		return;
3117 
3118 	if (likely(refcount_read(&skb->users) == 1)) {
3119 		smp_rmb();
3120 		refcount_set(&skb->users, 0);
3121 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3122 		return;
3123 	}
3124 	get_kfree_skb_cb(skb)->reason = reason;
3125 	local_irq_save(flags);
3126 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3127 	__this_cpu_write(softnet_data.completion_queue, skb);
3128 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3129 	local_irq_restore(flags);
3130 }
3131 EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
3132 
3133 void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3134 {
3135 	if (in_hardirq() || irqs_disabled())
3136 		dev_kfree_skb_irq_reason(skb, reason);
3137 	else
3138 		kfree_skb_reason(skb, reason);
3139 }
3140 EXPORT_SYMBOL(dev_kfree_skb_any_reason);
3141 
3142 
3143 /**
3144  * netif_device_detach - mark device as removed
3145  * @dev: network device
3146  *
3147  * Mark device as removed from system and therefore no longer available.
3148  */
3149 void netif_device_detach(struct net_device *dev)
3150 {
3151 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3152 	    netif_running(dev)) {
3153 		netif_tx_stop_all_queues(dev);
3154 	}
3155 }
3156 EXPORT_SYMBOL(netif_device_detach);
3157 
3158 /**
3159  * netif_device_attach - mark device as attached
3160  * @dev: network device
3161  *
3162  * Mark device as attached from system and restart if needed.
3163  */
3164 void netif_device_attach(struct net_device *dev)
3165 {
3166 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3167 	    netif_running(dev)) {
3168 		netif_tx_wake_all_queues(dev);
3169 		__netdev_watchdog_up(dev);
3170 	}
3171 }
3172 EXPORT_SYMBOL(netif_device_attach);
3173 
3174 /*
3175  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3176  * to be used as a distribution range.
3177  */
3178 static u16 skb_tx_hash(const struct net_device *dev,
3179 		       const struct net_device *sb_dev,
3180 		       struct sk_buff *skb)
3181 {
3182 	u32 hash;
3183 	u16 qoffset = 0;
3184 	u16 qcount = dev->real_num_tx_queues;
3185 
3186 	if (dev->num_tc) {
3187 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3188 
3189 		qoffset = sb_dev->tc_to_txq[tc].offset;
3190 		qcount = sb_dev->tc_to_txq[tc].count;
3191 		if (unlikely(!qcount)) {
3192 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3193 					     sb_dev->name, qoffset, tc);
3194 			qoffset = 0;
3195 			qcount = dev->real_num_tx_queues;
3196 		}
3197 	}
3198 
3199 	if (skb_rx_queue_recorded(skb)) {
3200 		DEBUG_NET_WARN_ON_ONCE(qcount == 0);
3201 		hash = skb_get_rx_queue(skb);
3202 		if (hash >= qoffset)
3203 			hash -= qoffset;
3204 		while (unlikely(hash >= qcount))
3205 			hash -= qcount;
3206 		return hash + qoffset;
3207 	}
3208 
3209 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3210 }
3211 
3212 static void skb_warn_bad_offload(const struct sk_buff *skb)
3213 {
3214 	static const netdev_features_t null_features;
3215 	struct net_device *dev = skb->dev;
3216 	const char *name = "";
3217 
3218 	if (!net_ratelimit())
3219 		return;
3220 
3221 	if (dev) {
3222 		if (dev->dev.parent)
3223 			name = dev_driver_string(dev->dev.parent);
3224 		else
3225 			name = netdev_name(dev);
3226 	}
3227 	skb_dump(KERN_WARNING, skb, false);
3228 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3229 	     name, dev ? &dev->features : &null_features,
3230 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3231 }
3232 
3233 /*
3234  * Invalidate hardware checksum when packet is to be mangled, and
3235  * complete checksum manually on outgoing path.
3236  */
3237 int skb_checksum_help(struct sk_buff *skb)
3238 {
3239 	__wsum csum;
3240 	int ret = 0, offset;
3241 
3242 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3243 		goto out_set_summed;
3244 
3245 	if (unlikely(skb_is_gso(skb))) {
3246 		skb_warn_bad_offload(skb);
3247 		return -EINVAL;
3248 	}
3249 
3250 	/* Before computing a checksum, we should make sure no frag could
3251 	 * be modified by an external entity : checksum could be wrong.
3252 	 */
3253 	if (skb_has_shared_frag(skb)) {
3254 		ret = __skb_linearize(skb);
3255 		if (ret)
3256 			goto out;
3257 	}
3258 
3259 	offset = skb_checksum_start_offset(skb);
3260 	ret = -EINVAL;
3261 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3262 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3263 		goto out;
3264 	}
3265 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3266 
3267 	offset += skb->csum_offset;
3268 	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
3269 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3270 		goto out;
3271 	}
3272 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3273 	if (ret)
3274 		goto out;
3275 
3276 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3277 out_set_summed:
3278 	skb->ip_summed = CHECKSUM_NONE;
3279 out:
3280 	return ret;
3281 }
3282 EXPORT_SYMBOL(skb_checksum_help);
3283 
3284 int skb_crc32c_csum_help(struct sk_buff *skb)
3285 {
3286 	__le32 crc32c_csum;
3287 	int ret = 0, offset, start;
3288 
3289 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3290 		goto out;
3291 
3292 	if (unlikely(skb_is_gso(skb)))
3293 		goto out;
3294 
3295 	/* Before computing a checksum, we should make sure no frag could
3296 	 * be modified by an external entity : checksum could be wrong.
3297 	 */
3298 	if (unlikely(skb_has_shared_frag(skb))) {
3299 		ret = __skb_linearize(skb);
3300 		if (ret)
3301 			goto out;
3302 	}
3303 	start = skb_checksum_start_offset(skb);
3304 	offset = start + offsetof(struct sctphdr, checksum);
3305 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3306 		ret = -EINVAL;
3307 		goto out;
3308 	}
3309 
3310 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3311 	if (ret)
3312 		goto out;
3313 
3314 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3315 						  skb->len - start, ~(__u32)0,
3316 						  crc32c_csum_stub));
3317 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3318 	skb_reset_csum_not_inet(skb);
3319 out:
3320 	return ret;
3321 }
3322 
3323 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3324 {
3325 	__be16 type = skb->protocol;
3326 
3327 	/* Tunnel gso handlers can set protocol to ethernet. */
3328 	if (type == htons(ETH_P_TEB)) {
3329 		struct ethhdr *eth;
3330 
3331 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3332 			return 0;
3333 
3334 		eth = (struct ethhdr *)skb->data;
3335 		type = eth->h_proto;
3336 	}
3337 
3338 	return vlan_get_protocol_and_depth(skb, type, depth);
3339 }
3340 
3341 /* openvswitch calls this on rx path, so we need a different check.
3342  */
3343 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3344 {
3345 	if (tx_path)
3346 		return skb->ip_summed != CHECKSUM_PARTIAL &&
3347 		       skb->ip_summed != CHECKSUM_UNNECESSARY;
3348 
3349 	return skb->ip_summed == CHECKSUM_NONE;
3350 }
3351 
3352 /**
3353  *	__skb_gso_segment - Perform segmentation on skb.
3354  *	@skb: buffer to segment
3355  *	@features: features for the output path (see dev->features)
3356  *	@tx_path: whether it is called in TX path
3357  *
3358  *	This function segments the given skb and returns a list of segments.
3359  *
3360  *	It may return NULL if the skb requires no segmentation.  This is
3361  *	only possible when GSO is used for verifying header integrity.
3362  *
3363  *	Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3364  */
3365 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3366 				  netdev_features_t features, bool tx_path)
3367 {
3368 	struct sk_buff *segs;
3369 
3370 	if (unlikely(skb_needs_check(skb, tx_path))) {
3371 		int err;
3372 
3373 		/* We're going to init ->check field in TCP or UDP header */
3374 		err = skb_cow_head(skb, 0);
3375 		if (err < 0)
3376 			return ERR_PTR(err);
3377 	}
3378 
3379 	/* Only report GSO partial support if it will enable us to
3380 	 * support segmentation on this frame without needing additional
3381 	 * work.
3382 	 */
3383 	if (features & NETIF_F_GSO_PARTIAL) {
3384 		netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3385 		struct net_device *dev = skb->dev;
3386 
3387 		partial_features |= dev->features & dev->gso_partial_features;
3388 		if (!skb_gso_ok(skb, features | partial_features))
3389 			features &= ~NETIF_F_GSO_PARTIAL;
3390 	}
3391 
3392 	BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3393 		     sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3394 
3395 	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3396 	SKB_GSO_CB(skb)->encap_level = 0;
3397 
3398 	skb_reset_mac_header(skb);
3399 	skb_reset_mac_len(skb);
3400 
3401 	segs = skb_mac_gso_segment(skb, features);
3402 
3403 	if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3404 		skb_warn_bad_offload(skb);
3405 
3406 	return segs;
3407 }
3408 EXPORT_SYMBOL(__skb_gso_segment);
3409 
3410 /* Take action when hardware reception checksum errors are detected. */
3411 #ifdef CONFIG_BUG
3412 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3413 {
3414 	netdev_err(dev, "hw csum failure\n");
3415 	skb_dump(KERN_ERR, skb, true);
3416 	dump_stack();
3417 }
3418 
3419 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3420 {
3421 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3422 }
3423 EXPORT_SYMBOL(netdev_rx_csum_fault);
3424 #endif
3425 
3426 /* XXX: check that highmem exists at all on the given machine. */
3427 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3428 {
3429 #ifdef CONFIG_HIGHMEM
3430 	int i;
3431 
3432 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3433 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3434 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3435 
3436 			if (PageHighMem(skb_frag_page(frag)))
3437 				return 1;
3438 		}
3439 	}
3440 #endif
3441 	return 0;
3442 }
3443 
3444 /* If MPLS offload request, verify we are testing hardware MPLS features
3445  * instead of standard features for the netdev.
3446  */
3447 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3448 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3449 					   netdev_features_t features,
3450 					   __be16 type)
3451 {
3452 	if (eth_p_mpls(type))
3453 		features &= skb->dev->mpls_features;
3454 
3455 	return features;
3456 }
3457 #else
3458 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3459 					   netdev_features_t features,
3460 					   __be16 type)
3461 {
3462 	return features;
3463 }
3464 #endif
3465 
3466 static netdev_features_t harmonize_features(struct sk_buff *skb,
3467 	netdev_features_t features)
3468 {
3469 	__be16 type;
3470 
3471 	type = skb_network_protocol(skb, NULL);
3472 	features = net_mpls_features(skb, features, type);
3473 
3474 	if (skb->ip_summed != CHECKSUM_NONE &&
3475 	    !can_checksum_protocol(features, type)) {
3476 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3477 	}
3478 	if (illegal_highdma(skb->dev, skb))
3479 		features &= ~NETIF_F_SG;
3480 
3481 	return features;
3482 }
3483 
3484 netdev_features_t passthru_features_check(struct sk_buff *skb,
3485 					  struct net_device *dev,
3486 					  netdev_features_t features)
3487 {
3488 	return features;
3489 }
3490 EXPORT_SYMBOL(passthru_features_check);
3491 
3492 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3493 					     struct net_device *dev,
3494 					     netdev_features_t features)
3495 {
3496 	return vlan_features_check(skb, features);
3497 }
3498 
3499 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3500 					    struct net_device *dev,
3501 					    netdev_features_t features)
3502 {
3503 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3504 
3505 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3506 		return features & ~NETIF_F_GSO_MASK;
3507 
3508 	if (!skb_shinfo(skb)->gso_type) {
3509 		skb_warn_bad_offload(skb);
3510 		return features & ~NETIF_F_GSO_MASK;
3511 	}
3512 
3513 	/* Support for GSO partial features requires software
3514 	 * intervention before we can actually process the packets
3515 	 * so we need to strip support for any partial features now
3516 	 * and we can pull them back in after we have partially
3517 	 * segmented the frame.
3518 	 */
3519 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3520 		features &= ~dev->gso_partial_features;
3521 
3522 	/* Make sure to clear the IPv4 ID mangling feature if the
3523 	 * IPv4 header has the potential to be fragmented.
3524 	 */
3525 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3526 		struct iphdr *iph = skb->encapsulation ?
3527 				    inner_ip_hdr(skb) : ip_hdr(skb);
3528 
3529 		if (!(iph->frag_off & htons(IP_DF)))
3530 			features &= ~NETIF_F_TSO_MANGLEID;
3531 	}
3532 
3533 	return features;
3534 }
3535 
3536 netdev_features_t netif_skb_features(struct sk_buff *skb)
3537 {
3538 	struct net_device *dev = skb->dev;
3539 	netdev_features_t features = dev->features;
3540 
3541 	if (skb_is_gso(skb))
3542 		features = gso_features_check(skb, dev, features);
3543 
3544 	/* If encapsulation offload request, verify we are testing
3545 	 * hardware encapsulation features instead of standard
3546 	 * features for the netdev
3547 	 */
3548 	if (skb->encapsulation)
3549 		features &= dev->hw_enc_features;
3550 
3551 	if (skb_vlan_tagged(skb))
3552 		features = netdev_intersect_features(features,
3553 						     dev->vlan_features |
3554 						     NETIF_F_HW_VLAN_CTAG_TX |
3555 						     NETIF_F_HW_VLAN_STAG_TX);
3556 
3557 	if (dev->netdev_ops->ndo_features_check)
3558 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3559 								features);
3560 	else
3561 		features &= dflt_features_check(skb, dev, features);
3562 
3563 	return harmonize_features(skb, features);
3564 }
3565 EXPORT_SYMBOL(netif_skb_features);
3566 
3567 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3568 		    struct netdev_queue *txq, bool more)
3569 {
3570 	unsigned int len;
3571 	int rc;
3572 
3573 	if (dev_nit_active(dev))
3574 		dev_queue_xmit_nit(skb, dev);
3575 
3576 	len = skb->len;
3577 	trace_net_dev_start_xmit(skb, dev);
3578 	rc = netdev_start_xmit(skb, dev, txq, more);
3579 	trace_net_dev_xmit(skb, rc, dev, len);
3580 
3581 	return rc;
3582 }
3583 
3584 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3585 				    struct netdev_queue *txq, int *ret)
3586 {
3587 	struct sk_buff *skb = first;
3588 	int rc = NETDEV_TX_OK;
3589 
3590 	while (skb) {
3591 		struct sk_buff *next = skb->next;
3592 
3593 		skb_mark_not_on_list(skb);
3594 		rc = xmit_one(skb, dev, txq, next != NULL);
3595 		if (unlikely(!dev_xmit_complete(rc))) {
3596 			skb->next = next;
3597 			goto out;
3598 		}
3599 
3600 		skb = next;
3601 		if (netif_tx_queue_stopped(txq) && skb) {
3602 			rc = NETDEV_TX_BUSY;
3603 			break;
3604 		}
3605 	}
3606 
3607 out:
3608 	*ret = rc;
3609 	return skb;
3610 }
3611 
3612 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3613 					  netdev_features_t features)
3614 {
3615 	if (skb_vlan_tag_present(skb) &&
3616 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3617 		skb = __vlan_hwaccel_push_inside(skb);
3618 	return skb;
3619 }
3620 
3621 int skb_csum_hwoffload_help(struct sk_buff *skb,
3622 			    const netdev_features_t features)
3623 {
3624 	if (unlikely(skb_csum_is_sctp(skb)))
3625 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3626 			skb_crc32c_csum_help(skb);
3627 
3628 	if (features & NETIF_F_HW_CSUM)
3629 		return 0;
3630 
3631 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3632 		switch (skb->csum_offset) {
3633 		case offsetof(struct tcphdr, check):
3634 		case offsetof(struct udphdr, check):
3635 			return 0;
3636 		}
3637 	}
3638 
3639 	return skb_checksum_help(skb);
3640 }
3641 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3642 
3643 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3644 {
3645 	netdev_features_t features;
3646 
3647 	features = netif_skb_features(skb);
3648 	skb = validate_xmit_vlan(skb, features);
3649 	if (unlikely(!skb))
3650 		goto out_null;
3651 
3652 	skb = sk_validate_xmit_skb(skb, dev);
3653 	if (unlikely(!skb))
3654 		goto out_null;
3655 
3656 	if (netif_needs_gso(skb, features)) {
3657 		struct sk_buff *segs;
3658 
3659 		segs = skb_gso_segment(skb, features);
3660 		if (IS_ERR(segs)) {
3661 			goto out_kfree_skb;
3662 		} else if (segs) {
3663 			consume_skb(skb);
3664 			skb = segs;
3665 		}
3666 	} else {
3667 		if (skb_needs_linearize(skb, features) &&
3668 		    __skb_linearize(skb))
3669 			goto out_kfree_skb;
3670 
3671 		/* If packet is not checksummed and device does not
3672 		 * support checksumming for this protocol, complete
3673 		 * checksumming here.
3674 		 */
3675 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3676 			if (skb->encapsulation)
3677 				skb_set_inner_transport_header(skb,
3678 							       skb_checksum_start_offset(skb));
3679 			else
3680 				skb_set_transport_header(skb,
3681 							 skb_checksum_start_offset(skb));
3682 			if (skb_csum_hwoffload_help(skb, features))
3683 				goto out_kfree_skb;
3684 		}
3685 	}
3686 
3687 	skb = validate_xmit_xfrm(skb, features, again);
3688 
3689 	return skb;
3690 
3691 out_kfree_skb:
3692 	kfree_skb(skb);
3693 out_null:
3694 	dev_core_stats_tx_dropped_inc(dev);
3695 	return NULL;
3696 }
3697 
3698 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3699 {
3700 	struct sk_buff *next, *head = NULL, *tail;
3701 
3702 	for (; skb != NULL; skb = next) {
3703 		next = skb->next;
3704 		skb_mark_not_on_list(skb);
3705 
3706 		/* in case skb wont be segmented, point to itself */
3707 		skb->prev = skb;
3708 
3709 		skb = validate_xmit_skb(skb, dev, again);
3710 		if (!skb)
3711 			continue;
3712 
3713 		if (!head)
3714 			head = skb;
3715 		else
3716 			tail->next = skb;
3717 		/* If skb was segmented, skb->prev points to
3718 		 * the last segment. If not, it still contains skb.
3719 		 */
3720 		tail = skb->prev;
3721 	}
3722 	return head;
3723 }
3724 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3725 
3726 static void qdisc_pkt_len_init(struct sk_buff *skb)
3727 {
3728 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3729 
3730 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3731 
3732 	/* To get more precise estimation of bytes sent on wire,
3733 	 * we add to pkt_len the headers size of all segments
3734 	 */
3735 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3736 		u16 gso_segs = shinfo->gso_segs;
3737 		unsigned int hdr_len;
3738 
3739 		/* mac layer + network layer */
3740 		hdr_len = skb_transport_offset(skb);
3741 
3742 		/* + transport layer */
3743 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3744 			const struct tcphdr *th;
3745 			struct tcphdr _tcphdr;
3746 
3747 			th = skb_header_pointer(skb, hdr_len,
3748 						sizeof(_tcphdr), &_tcphdr);
3749 			if (likely(th))
3750 				hdr_len += __tcp_hdrlen(th);
3751 		} else {
3752 			struct udphdr _udphdr;
3753 
3754 			if (skb_header_pointer(skb, hdr_len,
3755 					       sizeof(_udphdr), &_udphdr))
3756 				hdr_len += sizeof(struct udphdr);
3757 		}
3758 
3759 		if (shinfo->gso_type & SKB_GSO_DODGY)
3760 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3761 						shinfo->gso_size);
3762 
3763 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3764 	}
3765 }
3766 
3767 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3768 			     struct sk_buff **to_free,
3769 			     struct netdev_queue *txq)
3770 {
3771 	int rc;
3772 
3773 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3774 	if (rc == NET_XMIT_SUCCESS)
3775 		trace_qdisc_enqueue(q, txq, skb);
3776 	return rc;
3777 }
3778 
3779 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3780 				 struct net_device *dev,
3781 				 struct netdev_queue *txq)
3782 {
3783 	spinlock_t *root_lock = qdisc_lock(q);
3784 	struct sk_buff *to_free = NULL;
3785 	bool contended;
3786 	int rc;
3787 
3788 	qdisc_calculate_pkt_len(skb, q);
3789 
3790 	if (q->flags & TCQ_F_NOLOCK) {
3791 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3792 		    qdisc_run_begin(q)) {
3793 			/* Retest nolock_qdisc_is_empty() within the protection
3794 			 * of q->seqlock to protect from racing with requeuing.
3795 			 */
3796 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3797 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3798 				__qdisc_run(q);
3799 				qdisc_run_end(q);
3800 
3801 				goto no_lock_out;
3802 			}
3803 
3804 			qdisc_bstats_cpu_update(q, skb);
3805 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3806 			    !nolock_qdisc_is_empty(q))
3807 				__qdisc_run(q);
3808 
3809 			qdisc_run_end(q);
3810 			return NET_XMIT_SUCCESS;
3811 		}
3812 
3813 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3814 		qdisc_run(q);
3815 
3816 no_lock_out:
3817 		if (unlikely(to_free))
3818 			kfree_skb_list_reason(to_free,
3819 					      SKB_DROP_REASON_QDISC_DROP);
3820 		return rc;
3821 	}
3822 
3823 	/*
3824 	 * Heuristic to force contended enqueues to serialize on a
3825 	 * separate lock before trying to get qdisc main lock.
3826 	 * This permits qdisc->running owner to get the lock more
3827 	 * often and dequeue packets faster.
3828 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3829 	 * and then other tasks will only enqueue packets. The packets will be
3830 	 * sent after the qdisc owner is scheduled again. To prevent this
3831 	 * scenario the task always serialize on the lock.
3832 	 */
3833 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3834 	if (unlikely(contended))
3835 		spin_lock(&q->busylock);
3836 
3837 	spin_lock(root_lock);
3838 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3839 		__qdisc_drop(skb, &to_free);
3840 		rc = NET_XMIT_DROP;
3841 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3842 		   qdisc_run_begin(q)) {
3843 		/*
3844 		 * This is a work-conserving queue; there are no old skbs
3845 		 * waiting to be sent out; and the qdisc is not running -
3846 		 * xmit the skb directly.
3847 		 */
3848 
3849 		qdisc_bstats_update(q, skb);
3850 
3851 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3852 			if (unlikely(contended)) {
3853 				spin_unlock(&q->busylock);
3854 				contended = false;
3855 			}
3856 			__qdisc_run(q);
3857 		}
3858 
3859 		qdisc_run_end(q);
3860 		rc = NET_XMIT_SUCCESS;
3861 	} else {
3862 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3863 		if (qdisc_run_begin(q)) {
3864 			if (unlikely(contended)) {
3865 				spin_unlock(&q->busylock);
3866 				contended = false;
3867 			}
3868 			__qdisc_run(q);
3869 			qdisc_run_end(q);
3870 		}
3871 	}
3872 	spin_unlock(root_lock);
3873 	if (unlikely(to_free))
3874 		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3875 	if (unlikely(contended))
3876 		spin_unlock(&q->busylock);
3877 	return rc;
3878 }
3879 
3880 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3881 static void skb_update_prio(struct sk_buff *skb)
3882 {
3883 	const struct netprio_map *map;
3884 	const struct sock *sk;
3885 	unsigned int prioidx;
3886 
3887 	if (skb->priority)
3888 		return;
3889 	map = rcu_dereference_bh(skb->dev->priomap);
3890 	if (!map)
3891 		return;
3892 	sk = skb_to_full_sk(skb);
3893 	if (!sk)
3894 		return;
3895 
3896 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3897 
3898 	if (prioidx < map->priomap_len)
3899 		skb->priority = map->priomap[prioidx];
3900 }
3901 #else
3902 #define skb_update_prio(skb)
3903 #endif
3904 
3905 /**
3906  *	dev_loopback_xmit - loop back @skb
3907  *	@net: network namespace this loopback is happening in
3908  *	@sk:  sk needed to be a netfilter okfn
3909  *	@skb: buffer to transmit
3910  */
3911 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3912 {
3913 	skb_reset_mac_header(skb);
3914 	__skb_pull(skb, skb_network_offset(skb));
3915 	skb->pkt_type = PACKET_LOOPBACK;
3916 	if (skb->ip_summed == CHECKSUM_NONE)
3917 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3918 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3919 	skb_dst_force(skb);
3920 	netif_rx(skb);
3921 	return 0;
3922 }
3923 EXPORT_SYMBOL(dev_loopback_xmit);
3924 
3925 #ifdef CONFIG_NET_EGRESS
3926 static struct sk_buff *
3927 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3928 {
3929 #ifdef CONFIG_NET_CLS_ACT
3930 	struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3931 	struct tcf_result cl_res;
3932 
3933 	if (!miniq)
3934 		return skb;
3935 
3936 	/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3937 	tc_skb_cb(skb)->mru = 0;
3938 	tc_skb_cb(skb)->post_ct = false;
3939 	mini_qdisc_bstats_cpu_update(miniq, skb);
3940 
3941 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3942 	case TC_ACT_OK:
3943 	case TC_ACT_RECLASSIFY:
3944 		skb->tc_index = TC_H_MIN(cl_res.classid);
3945 		break;
3946 	case TC_ACT_SHOT:
3947 		mini_qdisc_qstats_cpu_drop(miniq);
3948 		*ret = NET_XMIT_DROP;
3949 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
3950 		return NULL;
3951 	case TC_ACT_STOLEN:
3952 	case TC_ACT_QUEUED:
3953 	case TC_ACT_TRAP:
3954 		*ret = NET_XMIT_SUCCESS;
3955 		consume_skb(skb);
3956 		return NULL;
3957 	case TC_ACT_REDIRECT:
3958 		/* No need to push/pop skb's mac_header here on egress! */
3959 		skb_do_redirect(skb);
3960 		*ret = NET_XMIT_SUCCESS;
3961 		return NULL;
3962 	default:
3963 		break;
3964 	}
3965 #endif /* CONFIG_NET_CLS_ACT */
3966 
3967 	return skb;
3968 }
3969 
3970 static struct netdev_queue *
3971 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3972 {
3973 	int qm = skb_get_queue_mapping(skb);
3974 
3975 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3976 }
3977 
3978 static bool netdev_xmit_txqueue_skipped(void)
3979 {
3980 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3981 }
3982 
3983 void netdev_xmit_skip_txqueue(bool skip)
3984 {
3985 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3986 }
3987 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3988 #endif /* CONFIG_NET_EGRESS */
3989 
3990 #ifdef CONFIG_XPS
3991 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
3992 			       struct xps_dev_maps *dev_maps, unsigned int tci)
3993 {
3994 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
3995 	struct xps_map *map;
3996 	int queue_index = -1;
3997 
3998 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
3999 		return queue_index;
4000 
4001 	tci *= dev_maps->num_tc;
4002 	tci += tc;
4003 
4004 	map = rcu_dereference(dev_maps->attr_map[tci]);
4005 	if (map) {
4006 		if (map->len == 1)
4007 			queue_index = map->queues[0];
4008 		else
4009 			queue_index = map->queues[reciprocal_scale(
4010 						skb_get_hash(skb), map->len)];
4011 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4012 			queue_index = -1;
4013 	}
4014 	return queue_index;
4015 }
4016 #endif
4017 
4018 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4019 			 struct sk_buff *skb)
4020 {
4021 #ifdef CONFIG_XPS
4022 	struct xps_dev_maps *dev_maps;
4023 	struct sock *sk = skb->sk;
4024 	int queue_index = -1;
4025 
4026 	if (!static_key_false(&xps_needed))
4027 		return -1;
4028 
4029 	rcu_read_lock();
4030 	if (!static_key_false(&xps_rxqs_needed))
4031 		goto get_cpus_map;
4032 
4033 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4034 	if (dev_maps) {
4035 		int tci = sk_rx_queue_get(sk);
4036 
4037 		if (tci >= 0)
4038 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4039 							  tci);
4040 	}
4041 
4042 get_cpus_map:
4043 	if (queue_index < 0) {
4044 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4045 		if (dev_maps) {
4046 			unsigned int tci = skb->sender_cpu - 1;
4047 
4048 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4049 							  tci);
4050 		}
4051 	}
4052 	rcu_read_unlock();
4053 
4054 	return queue_index;
4055 #else
4056 	return -1;
4057 #endif
4058 }
4059 
4060 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4061 		     struct net_device *sb_dev)
4062 {
4063 	return 0;
4064 }
4065 EXPORT_SYMBOL(dev_pick_tx_zero);
4066 
4067 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4068 		       struct net_device *sb_dev)
4069 {
4070 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4071 }
4072 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4073 
4074 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4075 		     struct net_device *sb_dev)
4076 {
4077 	struct sock *sk = skb->sk;
4078 	int queue_index = sk_tx_queue_get(sk);
4079 
4080 	sb_dev = sb_dev ? : dev;
4081 
4082 	if (queue_index < 0 || skb->ooo_okay ||
4083 	    queue_index >= dev->real_num_tx_queues) {
4084 		int new_index = get_xps_queue(dev, sb_dev, skb);
4085 
4086 		if (new_index < 0)
4087 			new_index = skb_tx_hash(dev, sb_dev, skb);
4088 
4089 		if (queue_index != new_index && sk &&
4090 		    sk_fullsock(sk) &&
4091 		    rcu_access_pointer(sk->sk_dst_cache))
4092 			sk_tx_queue_set(sk, new_index);
4093 
4094 		queue_index = new_index;
4095 	}
4096 
4097 	return queue_index;
4098 }
4099 EXPORT_SYMBOL(netdev_pick_tx);
4100 
4101 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4102 					 struct sk_buff *skb,
4103 					 struct net_device *sb_dev)
4104 {
4105 	int queue_index = 0;
4106 
4107 #ifdef CONFIG_XPS
4108 	u32 sender_cpu = skb->sender_cpu - 1;
4109 
4110 	if (sender_cpu >= (u32)NR_CPUS)
4111 		skb->sender_cpu = raw_smp_processor_id() + 1;
4112 #endif
4113 
4114 	if (dev->real_num_tx_queues != 1) {
4115 		const struct net_device_ops *ops = dev->netdev_ops;
4116 
4117 		if (ops->ndo_select_queue)
4118 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4119 		else
4120 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4121 
4122 		queue_index = netdev_cap_txqueue(dev, queue_index);
4123 	}
4124 
4125 	skb_set_queue_mapping(skb, queue_index);
4126 	return netdev_get_tx_queue(dev, queue_index);
4127 }
4128 
4129 /**
4130  * __dev_queue_xmit() - transmit a buffer
4131  * @skb:	buffer to transmit
4132  * @sb_dev:	suboordinate device used for L2 forwarding offload
4133  *
4134  * Queue a buffer for transmission to a network device. The caller must
4135  * have set the device and priority and built the buffer before calling
4136  * this function. The function can be called from an interrupt.
4137  *
4138  * When calling this method, interrupts MUST be enabled. This is because
4139  * the BH enable code must have IRQs enabled so that it will not deadlock.
4140  *
4141  * Regardless of the return value, the skb is consumed, so it is currently
4142  * difficult to retry a send to this method. (You can bump the ref count
4143  * before sending to hold a reference for retry if you are careful.)
4144  *
4145  * Return:
4146  * * 0				- buffer successfully transmitted
4147  * * positive qdisc return code	- NET_XMIT_DROP etc.
4148  * * negative errno		- other errors
4149  */
4150 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4151 {
4152 	struct net_device *dev = skb->dev;
4153 	struct netdev_queue *txq = NULL;
4154 	struct Qdisc *q;
4155 	int rc = -ENOMEM;
4156 	bool again = false;
4157 
4158 	skb_reset_mac_header(skb);
4159 	skb_assert_len(skb);
4160 
4161 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4162 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4163 
4164 	/* Disable soft irqs for various locks below. Also
4165 	 * stops preemption for RCU.
4166 	 */
4167 	rcu_read_lock_bh();
4168 
4169 	skb_update_prio(skb);
4170 
4171 	qdisc_pkt_len_init(skb);
4172 #ifdef CONFIG_NET_CLS_ACT
4173 	skb->tc_at_ingress = 0;
4174 #endif
4175 #ifdef CONFIG_NET_EGRESS
4176 	if (static_branch_unlikely(&egress_needed_key)) {
4177 		if (nf_hook_egress_active()) {
4178 			skb = nf_hook_egress(skb, &rc, dev);
4179 			if (!skb)
4180 				goto out;
4181 		}
4182 
4183 		netdev_xmit_skip_txqueue(false);
4184 
4185 		nf_skip_egress(skb, true);
4186 		skb = sch_handle_egress(skb, &rc, dev);
4187 		if (!skb)
4188 			goto out;
4189 		nf_skip_egress(skb, false);
4190 
4191 		if (netdev_xmit_txqueue_skipped())
4192 			txq = netdev_tx_queue_mapping(dev, skb);
4193 	}
4194 #endif
4195 	/* If device/qdisc don't need skb->dst, release it right now while
4196 	 * its hot in this cpu cache.
4197 	 */
4198 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4199 		skb_dst_drop(skb);
4200 	else
4201 		skb_dst_force(skb);
4202 
4203 	if (!txq)
4204 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4205 
4206 	q = rcu_dereference_bh(txq->qdisc);
4207 
4208 	trace_net_dev_queue(skb);
4209 	if (q->enqueue) {
4210 		rc = __dev_xmit_skb(skb, q, dev, txq);
4211 		goto out;
4212 	}
4213 
4214 	/* The device has no queue. Common case for software devices:
4215 	 * loopback, all the sorts of tunnels...
4216 
4217 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4218 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4219 	 * counters.)
4220 	 * However, it is possible, that they rely on protection
4221 	 * made by us here.
4222 
4223 	 * Check this and shot the lock. It is not prone from deadlocks.
4224 	 *Either shot noqueue qdisc, it is even simpler 8)
4225 	 */
4226 	if (dev->flags & IFF_UP) {
4227 		int cpu = smp_processor_id(); /* ok because BHs are off */
4228 
4229 		/* Other cpus might concurrently change txq->xmit_lock_owner
4230 		 * to -1 or to their cpu id, but not to our id.
4231 		 */
4232 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4233 			if (dev_xmit_recursion())
4234 				goto recursion_alert;
4235 
4236 			skb = validate_xmit_skb(skb, dev, &again);
4237 			if (!skb)
4238 				goto out;
4239 
4240 			HARD_TX_LOCK(dev, txq, cpu);
4241 
4242 			if (!netif_xmit_stopped(txq)) {
4243 				dev_xmit_recursion_inc();
4244 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4245 				dev_xmit_recursion_dec();
4246 				if (dev_xmit_complete(rc)) {
4247 					HARD_TX_UNLOCK(dev, txq);
4248 					goto out;
4249 				}
4250 			}
4251 			HARD_TX_UNLOCK(dev, txq);
4252 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4253 					     dev->name);
4254 		} else {
4255 			/* Recursion is detected! It is possible,
4256 			 * unfortunately
4257 			 */
4258 recursion_alert:
4259 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4260 					     dev->name);
4261 		}
4262 	}
4263 
4264 	rc = -ENETDOWN;
4265 	rcu_read_unlock_bh();
4266 
4267 	dev_core_stats_tx_dropped_inc(dev);
4268 	kfree_skb_list(skb);
4269 	return rc;
4270 out:
4271 	rcu_read_unlock_bh();
4272 	return rc;
4273 }
4274 EXPORT_SYMBOL(__dev_queue_xmit);
4275 
4276 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4277 {
4278 	struct net_device *dev = skb->dev;
4279 	struct sk_buff *orig_skb = skb;
4280 	struct netdev_queue *txq;
4281 	int ret = NETDEV_TX_BUSY;
4282 	bool again = false;
4283 
4284 	if (unlikely(!netif_running(dev) ||
4285 		     !netif_carrier_ok(dev)))
4286 		goto drop;
4287 
4288 	skb = validate_xmit_skb_list(skb, dev, &again);
4289 	if (skb != orig_skb)
4290 		goto drop;
4291 
4292 	skb_set_queue_mapping(skb, queue_id);
4293 	txq = skb_get_tx_queue(dev, skb);
4294 
4295 	local_bh_disable();
4296 
4297 	dev_xmit_recursion_inc();
4298 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4299 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4300 		ret = netdev_start_xmit(skb, dev, txq, false);
4301 	HARD_TX_UNLOCK(dev, txq);
4302 	dev_xmit_recursion_dec();
4303 
4304 	local_bh_enable();
4305 	return ret;
4306 drop:
4307 	dev_core_stats_tx_dropped_inc(dev);
4308 	kfree_skb_list(skb);
4309 	return NET_XMIT_DROP;
4310 }
4311 EXPORT_SYMBOL(__dev_direct_xmit);
4312 
4313 /*************************************************************************
4314  *			Receiver routines
4315  *************************************************************************/
4316 
4317 int netdev_max_backlog __read_mostly = 1000;
4318 EXPORT_SYMBOL(netdev_max_backlog);
4319 
4320 int netdev_tstamp_prequeue __read_mostly = 1;
4321 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4322 int netdev_budget __read_mostly = 300;
4323 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4324 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4325 int weight_p __read_mostly = 64;           /* old backlog weight */
4326 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4327 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4328 int dev_rx_weight __read_mostly = 64;
4329 int dev_tx_weight __read_mostly = 64;
4330 
4331 /* Called with irq disabled */
4332 static inline void ____napi_schedule(struct softnet_data *sd,
4333 				     struct napi_struct *napi)
4334 {
4335 	struct task_struct *thread;
4336 
4337 	lockdep_assert_irqs_disabled();
4338 
4339 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4340 		/* Paired with smp_mb__before_atomic() in
4341 		 * napi_enable()/dev_set_threaded().
4342 		 * Use READ_ONCE() to guarantee a complete
4343 		 * read on napi->thread. Only call
4344 		 * wake_up_process() when it's not NULL.
4345 		 */
4346 		thread = READ_ONCE(napi->thread);
4347 		if (thread) {
4348 			/* Avoid doing set_bit() if the thread is in
4349 			 * INTERRUPTIBLE state, cause napi_thread_wait()
4350 			 * makes sure to proceed with napi polling
4351 			 * if the thread is explicitly woken from here.
4352 			 */
4353 			if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4354 				set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4355 			wake_up_process(thread);
4356 			return;
4357 		}
4358 	}
4359 
4360 	list_add_tail(&napi->poll_list, &sd->poll_list);
4361 	WRITE_ONCE(napi->list_owner, smp_processor_id());
4362 	/* If not called from net_rx_action()
4363 	 * we have to raise NET_RX_SOFTIRQ.
4364 	 */
4365 	if (!sd->in_net_rx_action)
4366 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4367 }
4368 
4369 #ifdef CONFIG_RPS
4370 
4371 /* One global table that all flow-based protocols share. */
4372 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4373 EXPORT_SYMBOL(rps_sock_flow_table);
4374 u32 rps_cpu_mask __read_mostly;
4375 EXPORT_SYMBOL(rps_cpu_mask);
4376 
4377 struct static_key_false rps_needed __read_mostly;
4378 EXPORT_SYMBOL(rps_needed);
4379 struct static_key_false rfs_needed __read_mostly;
4380 EXPORT_SYMBOL(rfs_needed);
4381 
4382 static struct rps_dev_flow *
4383 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4384 	    struct rps_dev_flow *rflow, u16 next_cpu)
4385 {
4386 	if (next_cpu < nr_cpu_ids) {
4387 #ifdef CONFIG_RFS_ACCEL
4388 		struct netdev_rx_queue *rxqueue;
4389 		struct rps_dev_flow_table *flow_table;
4390 		struct rps_dev_flow *old_rflow;
4391 		u32 flow_id;
4392 		u16 rxq_index;
4393 		int rc;
4394 
4395 		/* Should we steer this flow to a different hardware queue? */
4396 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4397 		    !(dev->features & NETIF_F_NTUPLE))
4398 			goto out;
4399 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4400 		if (rxq_index == skb_get_rx_queue(skb))
4401 			goto out;
4402 
4403 		rxqueue = dev->_rx + rxq_index;
4404 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4405 		if (!flow_table)
4406 			goto out;
4407 		flow_id = skb_get_hash(skb) & flow_table->mask;
4408 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4409 							rxq_index, flow_id);
4410 		if (rc < 0)
4411 			goto out;
4412 		old_rflow = rflow;
4413 		rflow = &flow_table->flows[flow_id];
4414 		rflow->filter = rc;
4415 		if (old_rflow->filter == rflow->filter)
4416 			old_rflow->filter = RPS_NO_FILTER;
4417 	out:
4418 #endif
4419 		rflow->last_qtail =
4420 			per_cpu(softnet_data, next_cpu).input_queue_head;
4421 	}
4422 
4423 	rflow->cpu = next_cpu;
4424 	return rflow;
4425 }
4426 
4427 /*
4428  * get_rps_cpu is called from netif_receive_skb and returns the target
4429  * CPU from the RPS map of the receiving queue for a given skb.
4430  * rcu_read_lock must be held on entry.
4431  */
4432 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4433 		       struct rps_dev_flow **rflowp)
4434 {
4435 	const struct rps_sock_flow_table *sock_flow_table;
4436 	struct netdev_rx_queue *rxqueue = dev->_rx;
4437 	struct rps_dev_flow_table *flow_table;
4438 	struct rps_map *map;
4439 	int cpu = -1;
4440 	u32 tcpu;
4441 	u32 hash;
4442 
4443 	if (skb_rx_queue_recorded(skb)) {
4444 		u16 index = skb_get_rx_queue(skb);
4445 
4446 		if (unlikely(index >= dev->real_num_rx_queues)) {
4447 			WARN_ONCE(dev->real_num_rx_queues > 1,
4448 				  "%s received packet on queue %u, but number "
4449 				  "of RX queues is %u\n",
4450 				  dev->name, index, dev->real_num_rx_queues);
4451 			goto done;
4452 		}
4453 		rxqueue += index;
4454 	}
4455 
4456 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4457 
4458 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4459 	map = rcu_dereference(rxqueue->rps_map);
4460 	if (!flow_table && !map)
4461 		goto done;
4462 
4463 	skb_reset_network_header(skb);
4464 	hash = skb_get_hash(skb);
4465 	if (!hash)
4466 		goto done;
4467 
4468 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
4469 	if (flow_table && sock_flow_table) {
4470 		struct rps_dev_flow *rflow;
4471 		u32 next_cpu;
4472 		u32 ident;
4473 
4474 		/* First check into global flow table if there is a match.
4475 		 * This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow().
4476 		 */
4477 		ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]);
4478 		if ((ident ^ hash) & ~rps_cpu_mask)
4479 			goto try_rps;
4480 
4481 		next_cpu = ident & rps_cpu_mask;
4482 
4483 		/* OK, now we know there is a match,
4484 		 * we can look at the local (per receive queue) flow table
4485 		 */
4486 		rflow = &flow_table->flows[hash & flow_table->mask];
4487 		tcpu = rflow->cpu;
4488 
4489 		/*
4490 		 * If the desired CPU (where last recvmsg was done) is
4491 		 * different from current CPU (one in the rx-queue flow
4492 		 * table entry), switch if one of the following holds:
4493 		 *   - Current CPU is unset (>= nr_cpu_ids).
4494 		 *   - Current CPU is offline.
4495 		 *   - The current CPU's queue tail has advanced beyond the
4496 		 *     last packet that was enqueued using this table entry.
4497 		 *     This guarantees that all previous packets for the flow
4498 		 *     have been dequeued, thus preserving in order delivery.
4499 		 */
4500 		if (unlikely(tcpu != next_cpu) &&
4501 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4502 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4503 		      rflow->last_qtail)) >= 0)) {
4504 			tcpu = next_cpu;
4505 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4506 		}
4507 
4508 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4509 			*rflowp = rflow;
4510 			cpu = tcpu;
4511 			goto done;
4512 		}
4513 	}
4514 
4515 try_rps:
4516 
4517 	if (map) {
4518 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4519 		if (cpu_online(tcpu)) {
4520 			cpu = tcpu;
4521 			goto done;
4522 		}
4523 	}
4524 
4525 done:
4526 	return cpu;
4527 }
4528 
4529 #ifdef CONFIG_RFS_ACCEL
4530 
4531 /**
4532  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4533  * @dev: Device on which the filter was set
4534  * @rxq_index: RX queue index
4535  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4536  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4537  *
4538  * Drivers that implement ndo_rx_flow_steer() should periodically call
4539  * this function for each installed filter and remove the filters for
4540  * which it returns %true.
4541  */
4542 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4543 			 u32 flow_id, u16 filter_id)
4544 {
4545 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4546 	struct rps_dev_flow_table *flow_table;
4547 	struct rps_dev_flow *rflow;
4548 	bool expire = true;
4549 	unsigned int cpu;
4550 
4551 	rcu_read_lock();
4552 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4553 	if (flow_table && flow_id <= flow_table->mask) {
4554 		rflow = &flow_table->flows[flow_id];
4555 		cpu = READ_ONCE(rflow->cpu);
4556 		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4557 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4558 			   rflow->last_qtail) <
4559 		     (int)(10 * flow_table->mask)))
4560 			expire = false;
4561 	}
4562 	rcu_read_unlock();
4563 	return expire;
4564 }
4565 EXPORT_SYMBOL(rps_may_expire_flow);
4566 
4567 #endif /* CONFIG_RFS_ACCEL */
4568 
4569 /* Called from hardirq (IPI) context */
4570 static void rps_trigger_softirq(void *data)
4571 {
4572 	struct softnet_data *sd = data;
4573 
4574 	____napi_schedule(sd, &sd->backlog);
4575 	sd->received_rps++;
4576 }
4577 
4578 #endif /* CONFIG_RPS */
4579 
4580 /* Called from hardirq (IPI) context */
4581 static void trigger_rx_softirq(void *data)
4582 {
4583 	struct softnet_data *sd = data;
4584 
4585 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4586 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4587 }
4588 
4589 /*
4590  * After we queued a packet into sd->input_pkt_queue,
4591  * we need to make sure this queue is serviced soon.
4592  *
4593  * - If this is another cpu queue, link it to our rps_ipi_list,
4594  *   and make sure we will process rps_ipi_list from net_rx_action().
4595  *
4596  * - If this is our own queue, NAPI schedule our backlog.
4597  *   Note that this also raises NET_RX_SOFTIRQ.
4598  */
4599 static void napi_schedule_rps(struct softnet_data *sd)
4600 {
4601 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4602 
4603 #ifdef CONFIG_RPS
4604 	if (sd != mysd) {
4605 		sd->rps_ipi_next = mysd->rps_ipi_list;
4606 		mysd->rps_ipi_list = sd;
4607 
4608 		/* If not called from net_rx_action() or napi_threaded_poll()
4609 		 * we have to raise NET_RX_SOFTIRQ.
4610 		 */
4611 		if (!mysd->in_net_rx_action && !mysd->in_napi_threaded_poll)
4612 			__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4613 		return;
4614 	}
4615 #endif /* CONFIG_RPS */
4616 	__napi_schedule_irqoff(&mysd->backlog);
4617 }
4618 
4619 #ifdef CONFIG_NET_FLOW_LIMIT
4620 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4621 #endif
4622 
4623 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4624 {
4625 #ifdef CONFIG_NET_FLOW_LIMIT
4626 	struct sd_flow_limit *fl;
4627 	struct softnet_data *sd;
4628 	unsigned int old_flow, new_flow;
4629 
4630 	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4631 		return false;
4632 
4633 	sd = this_cpu_ptr(&softnet_data);
4634 
4635 	rcu_read_lock();
4636 	fl = rcu_dereference(sd->flow_limit);
4637 	if (fl) {
4638 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4639 		old_flow = fl->history[fl->history_head];
4640 		fl->history[fl->history_head] = new_flow;
4641 
4642 		fl->history_head++;
4643 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4644 
4645 		if (likely(fl->buckets[old_flow]))
4646 			fl->buckets[old_flow]--;
4647 
4648 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4649 			fl->count++;
4650 			rcu_read_unlock();
4651 			return true;
4652 		}
4653 	}
4654 	rcu_read_unlock();
4655 #endif
4656 	return false;
4657 }
4658 
4659 /*
4660  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4661  * queue (may be a remote CPU queue).
4662  */
4663 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4664 			      unsigned int *qtail)
4665 {
4666 	enum skb_drop_reason reason;
4667 	struct softnet_data *sd;
4668 	unsigned long flags;
4669 	unsigned int qlen;
4670 
4671 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
4672 	sd = &per_cpu(softnet_data, cpu);
4673 
4674 	rps_lock_irqsave(sd, &flags);
4675 	if (!netif_running(skb->dev))
4676 		goto drop;
4677 	qlen = skb_queue_len(&sd->input_pkt_queue);
4678 	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4679 		if (qlen) {
4680 enqueue:
4681 			__skb_queue_tail(&sd->input_pkt_queue, skb);
4682 			input_queue_tail_incr_save(sd, qtail);
4683 			rps_unlock_irq_restore(sd, &flags);
4684 			return NET_RX_SUCCESS;
4685 		}
4686 
4687 		/* Schedule NAPI for backlog device
4688 		 * We can use non atomic operation since we own the queue lock
4689 		 */
4690 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4691 			napi_schedule_rps(sd);
4692 		goto enqueue;
4693 	}
4694 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4695 
4696 drop:
4697 	sd->dropped++;
4698 	rps_unlock_irq_restore(sd, &flags);
4699 
4700 	dev_core_stats_rx_dropped_inc(skb->dev);
4701 	kfree_skb_reason(skb, reason);
4702 	return NET_RX_DROP;
4703 }
4704 
4705 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4706 {
4707 	struct net_device *dev = skb->dev;
4708 	struct netdev_rx_queue *rxqueue;
4709 
4710 	rxqueue = dev->_rx;
4711 
4712 	if (skb_rx_queue_recorded(skb)) {
4713 		u16 index = skb_get_rx_queue(skb);
4714 
4715 		if (unlikely(index >= dev->real_num_rx_queues)) {
4716 			WARN_ONCE(dev->real_num_rx_queues > 1,
4717 				  "%s received packet on queue %u, but number "
4718 				  "of RX queues is %u\n",
4719 				  dev->name, index, dev->real_num_rx_queues);
4720 
4721 			return rxqueue; /* Return first rxqueue */
4722 		}
4723 		rxqueue += index;
4724 	}
4725 	return rxqueue;
4726 }
4727 
4728 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4729 			     struct bpf_prog *xdp_prog)
4730 {
4731 	void *orig_data, *orig_data_end, *hard_start;
4732 	struct netdev_rx_queue *rxqueue;
4733 	bool orig_bcast, orig_host;
4734 	u32 mac_len, frame_sz;
4735 	__be16 orig_eth_type;
4736 	struct ethhdr *eth;
4737 	u32 metalen, act;
4738 	int off;
4739 
4740 	/* The XDP program wants to see the packet starting at the MAC
4741 	 * header.
4742 	 */
4743 	mac_len = skb->data - skb_mac_header(skb);
4744 	hard_start = skb->data - skb_headroom(skb);
4745 
4746 	/* SKB "head" area always have tailroom for skb_shared_info */
4747 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4748 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4749 
4750 	rxqueue = netif_get_rxqueue(skb);
4751 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4752 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4753 			 skb_headlen(skb) + mac_len, true);
4754 
4755 	orig_data_end = xdp->data_end;
4756 	orig_data = xdp->data;
4757 	eth = (struct ethhdr *)xdp->data;
4758 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4759 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4760 	orig_eth_type = eth->h_proto;
4761 
4762 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4763 
4764 	/* check if bpf_xdp_adjust_head was used */
4765 	off = xdp->data - orig_data;
4766 	if (off) {
4767 		if (off > 0)
4768 			__skb_pull(skb, off);
4769 		else if (off < 0)
4770 			__skb_push(skb, -off);
4771 
4772 		skb->mac_header += off;
4773 		skb_reset_network_header(skb);
4774 	}
4775 
4776 	/* check if bpf_xdp_adjust_tail was used */
4777 	off = xdp->data_end - orig_data_end;
4778 	if (off != 0) {
4779 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4780 		skb->len += off; /* positive on grow, negative on shrink */
4781 	}
4782 
4783 	/* check if XDP changed eth hdr such SKB needs update */
4784 	eth = (struct ethhdr *)xdp->data;
4785 	if ((orig_eth_type != eth->h_proto) ||
4786 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4787 						  skb->dev->dev_addr)) ||
4788 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4789 		__skb_push(skb, ETH_HLEN);
4790 		skb->pkt_type = PACKET_HOST;
4791 		skb->protocol = eth_type_trans(skb, skb->dev);
4792 	}
4793 
4794 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4795 	 * before calling us again on redirect path. We do not call do_redirect
4796 	 * as we leave that up to the caller.
4797 	 *
4798 	 * Caller is responsible for managing lifetime of skb (i.e. calling
4799 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
4800 	 */
4801 	switch (act) {
4802 	case XDP_REDIRECT:
4803 	case XDP_TX:
4804 		__skb_push(skb, mac_len);
4805 		break;
4806 	case XDP_PASS:
4807 		metalen = xdp->data - xdp->data_meta;
4808 		if (metalen)
4809 			skb_metadata_set(skb, metalen);
4810 		break;
4811 	}
4812 
4813 	return act;
4814 }
4815 
4816 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4817 				     struct xdp_buff *xdp,
4818 				     struct bpf_prog *xdp_prog)
4819 {
4820 	u32 act = XDP_DROP;
4821 
4822 	/* Reinjected packets coming from act_mirred or similar should
4823 	 * not get XDP generic processing.
4824 	 */
4825 	if (skb_is_redirected(skb))
4826 		return XDP_PASS;
4827 
4828 	/* XDP packets must be linear and must have sufficient headroom
4829 	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4830 	 * native XDP provides, thus we need to do it here as well.
4831 	 */
4832 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4833 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4834 		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4835 		int troom = skb->tail + skb->data_len - skb->end;
4836 
4837 		/* In case we have to go down the path and also linearize,
4838 		 * then lets do the pskb_expand_head() work just once here.
4839 		 */
4840 		if (pskb_expand_head(skb,
4841 				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4842 				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4843 			goto do_drop;
4844 		if (skb_linearize(skb))
4845 			goto do_drop;
4846 	}
4847 
4848 	act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4849 	switch (act) {
4850 	case XDP_REDIRECT:
4851 	case XDP_TX:
4852 	case XDP_PASS:
4853 		break;
4854 	default:
4855 		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4856 		fallthrough;
4857 	case XDP_ABORTED:
4858 		trace_xdp_exception(skb->dev, xdp_prog, act);
4859 		fallthrough;
4860 	case XDP_DROP:
4861 	do_drop:
4862 		kfree_skb(skb);
4863 		break;
4864 	}
4865 
4866 	return act;
4867 }
4868 
4869 /* When doing generic XDP we have to bypass the qdisc layer and the
4870  * network taps in order to match in-driver-XDP behavior. This also means
4871  * that XDP packets are able to starve other packets going through a qdisc,
4872  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
4873  * queues, so they do not have this starvation issue.
4874  */
4875 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4876 {
4877 	struct net_device *dev = skb->dev;
4878 	struct netdev_queue *txq;
4879 	bool free_skb = true;
4880 	int cpu, rc;
4881 
4882 	txq = netdev_core_pick_tx(dev, skb, NULL);
4883 	cpu = smp_processor_id();
4884 	HARD_TX_LOCK(dev, txq, cpu);
4885 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
4886 		rc = netdev_start_xmit(skb, dev, txq, 0);
4887 		if (dev_xmit_complete(rc))
4888 			free_skb = false;
4889 	}
4890 	HARD_TX_UNLOCK(dev, txq);
4891 	if (free_skb) {
4892 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
4893 		dev_core_stats_tx_dropped_inc(dev);
4894 		kfree_skb(skb);
4895 	}
4896 }
4897 
4898 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4899 
4900 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4901 {
4902 	if (xdp_prog) {
4903 		struct xdp_buff xdp;
4904 		u32 act;
4905 		int err;
4906 
4907 		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4908 		if (act != XDP_PASS) {
4909 			switch (act) {
4910 			case XDP_REDIRECT:
4911 				err = xdp_do_generic_redirect(skb->dev, skb,
4912 							      &xdp, xdp_prog);
4913 				if (err)
4914 					goto out_redir;
4915 				break;
4916 			case XDP_TX:
4917 				generic_xdp_tx(skb, xdp_prog);
4918 				break;
4919 			}
4920 			return XDP_DROP;
4921 		}
4922 	}
4923 	return XDP_PASS;
4924 out_redir:
4925 	kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
4926 	return XDP_DROP;
4927 }
4928 EXPORT_SYMBOL_GPL(do_xdp_generic);
4929 
4930 static int netif_rx_internal(struct sk_buff *skb)
4931 {
4932 	int ret;
4933 
4934 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
4935 
4936 	trace_netif_rx(skb);
4937 
4938 #ifdef CONFIG_RPS
4939 	if (static_branch_unlikely(&rps_needed)) {
4940 		struct rps_dev_flow voidflow, *rflow = &voidflow;
4941 		int cpu;
4942 
4943 		rcu_read_lock();
4944 
4945 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
4946 		if (cpu < 0)
4947 			cpu = smp_processor_id();
4948 
4949 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4950 
4951 		rcu_read_unlock();
4952 	} else
4953 #endif
4954 	{
4955 		unsigned int qtail;
4956 
4957 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
4958 	}
4959 	return ret;
4960 }
4961 
4962 /**
4963  *	__netif_rx	-	Slightly optimized version of netif_rx
4964  *	@skb: buffer to post
4965  *
4966  *	This behaves as netif_rx except that it does not disable bottom halves.
4967  *	As a result this function may only be invoked from the interrupt context
4968  *	(either hard or soft interrupt).
4969  */
4970 int __netif_rx(struct sk_buff *skb)
4971 {
4972 	int ret;
4973 
4974 	lockdep_assert_once(hardirq_count() | softirq_count());
4975 
4976 	trace_netif_rx_entry(skb);
4977 	ret = netif_rx_internal(skb);
4978 	trace_netif_rx_exit(ret);
4979 	return ret;
4980 }
4981 EXPORT_SYMBOL(__netif_rx);
4982 
4983 /**
4984  *	netif_rx	-	post buffer to the network code
4985  *	@skb: buffer to post
4986  *
4987  *	This function receives a packet from a device driver and queues it for
4988  *	the upper (protocol) levels to process via the backlog NAPI device. It
4989  *	always succeeds. The buffer may be dropped during processing for
4990  *	congestion control or by the protocol layers.
4991  *	The network buffer is passed via the backlog NAPI device. Modern NIC
4992  *	driver should use NAPI and GRO.
4993  *	This function can used from interrupt and from process context. The
4994  *	caller from process context must not disable interrupts before invoking
4995  *	this function.
4996  *
4997  *	return values:
4998  *	NET_RX_SUCCESS	(no congestion)
4999  *	NET_RX_DROP     (packet was dropped)
5000  *
5001  */
5002 int netif_rx(struct sk_buff *skb)
5003 {
5004 	bool need_bh_off = !(hardirq_count() | softirq_count());
5005 	int ret;
5006 
5007 	if (need_bh_off)
5008 		local_bh_disable();
5009 	trace_netif_rx_entry(skb);
5010 	ret = netif_rx_internal(skb);
5011 	trace_netif_rx_exit(ret);
5012 	if (need_bh_off)
5013 		local_bh_enable();
5014 	return ret;
5015 }
5016 EXPORT_SYMBOL(netif_rx);
5017 
5018 static __latent_entropy void net_tx_action(struct softirq_action *h)
5019 {
5020 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5021 
5022 	if (sd->completion_queue) {
5023 		struct sk_buff *clist;
5024 
5025 		local_irq_disable();
5026 		clist = sd->completion_queue;
5027 		sd->completion_queue = NULL;
5028 		local_irq_enable();
5029 
5030 		while (clist) {
5031 			struct sk_buff *skb = clist;
5032 
5033 			clist = clist->next;
5034 
5035 			WARN_ON(refcount_read(&skb->users));
5036 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
5037 				trace_consume_skb(skb, net_tx_action);
5038 			else
5039 				trace_kfree_skb(skb, net_tx_action,
5040 						get_kfree_skb_cb(skb)->reason);
5041 
5042 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5043 				__kfree_skb(skb);
5044 			else
5045 				__napi_kfree_skb(skb,
5046 						 get_kfree_skb_cb(skb)->reason);
5047 		}
5048 	}
5049 
5050 	if (sd->output_queue) {
5051 		struct Qdisc *head;
5052 
5053 		local_irq_disable();
5054 		head = sd->output_queue;
5055 		sd->output_queue = NULL;
5056 		sd->output_queue_tailp = &sd->output_queue;
5057 		local_irq_enable();
5058 
5059 		rcu_read_lock();
5060 
5061 		while (head) {
5062 			struct Qdisc *q = head;
5063 			spinlock_t *root_lock = NULL;
5064 
5065 			head = head->next_sched;
5066 
5067 			/* We need to make sure head->next_sched is read
5068 			 * before clearing __QDISC_STATE_SCHED
5069 			 */
5070 			smp_mb__before_atomic();
5071 
5072 			if (!(q->flags & TCQ_F_NOLOCK)) {
5073 				root_lock = qdisc_lock(q);
5074 				spin_lock(root_lock);
5075 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5076 						     &q->state))) {
5077 				/* There is a synchronize_net() between
5078 				 * STATE_DEACTIVATED flag being set and
5079 				 * qdisc_reset()/some_qdisc_is_busy() in
5080 				 * dev_deactivate(), so we can safely bail out
5081 				 * early here to avoid data race between
5082 				 * qdisc_deactivate() and some_qdisc_is_busy()
5083 				 * for lockless qdisc.
5084 				 */
5085 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5086 				continue;
5087 			}
5088 
5089 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5090 			qdisc_run(q);
5091 			if (root_lock)
5092 				spin_unlock(root_lock);
5093 		}
5094 
5095 		rcu_read_unlock();
5096 	}
5097 
5098 	xfrm_dev_backlog(sd);
5099 }
5100 
5101 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5102 /* This hook is defined here for ATM LANE */
5103 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5104 			     unsigned char *addr) __read_mostly;
5105 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5106 #endif
5107 
5108 static inline struct sk_buff *
5109 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5110 		   struct net_device *orig_dev, bool *another)
5111 {
5112 #ifdef CONFIG_NET_CLS_ACT
5113 	struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5114 	struct tcf_result cl_res;
5115 
5116 	/* If there's at least one ingress present somewhere (so
5117 	 * we get here via enabled static key), remaining devices
5118 	 * that are not configured with an ingress qdisc will bail
5119 	 * out here.
5120 	 */
5121 	if (!miniq)
5122 		return skb;
5123 
5124 	if (*pt_prev) {
5125 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
5126 		*pt_prev = NULL;
5127 	}
5128 
5129 	qdisc_skb_cb(skb)->pkt_len = skb->len;
5130 	tc_skb_cb(skb)->mru = 0;
5131 	tc_skb_cb(skb)->post_ct = false;
5132 	skb->tc_at_ingress = 1;
5133 	mini_qdisc_bstats_cpu_update(miniq, skb);
5134 
5135 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5136 	case TC_ACT_OK:
5137 	case TC_ACT_RECLASSIFY:
5138 		skb->tc_index = TC_H_MIN(cl_res.classid);
5139 		break;
5140 	case TC_ACT_SHOT:
5141 		mini_qdisc_qstats_cpu_drop(miniq);
5142 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
5143 		*ret = NET_RX_DROP;
5144 		return NULL;
5145 	case TC_ACT_STOLEN:
5146 	case TC_ACT_QUEUED:
5147 	case TC_ACT_TRAP:
5148 		consume_skb(skb);
5149 		*ret = NET_RX_SUCCESS;
5150 		return NULL;
5151 	case TC_ACT_REDIRECT:
5152 		/* skb_mac_header check was done by cls/act_bpf, so
5153 		 * we can safely push the L2 header back before
5154 		 * redirecting to another netdev
5155 		 */
5156 		__skb_push(skb, skb->mac_len);
5157 		if (skb_do_redirect(skb) == -EAGAIN) {
5158 			__skb_pull(skb, skb->mac_len);
5159 			*another = true;
5160 			break;
5161 		}
5162 		*ret = NET_RX_SUCCESS;
5163 		return NULL;
5164 	case TC_ACT_CONSUMED:
5165 		*ret = NET_RX_SUCCESS;
5166 		return NULL;
5167 	default:
5168 		break;
5169 	}
5170 #endif /* CONFIG_NET_CLS_ACT */
5171 	return skb;
5172 }
5173 
5174 /**
5175  *	netdev_is_rx_handler_busy - check if receive handler is registered
5176  *	@dev: device to check
5177  *
5178  *	Check if a receive handler is already registered for a given device.
5179  *	Return true if there one.
5180  *
5181  *	The caller must hold the rtnl_mutex.
5182  */
5183 bool netdev_is_rx_handler_busy(struct net_device *dev)
5184 {
5185 	ASSERT_RTNL();
5186 	return dev && rtnl_dereference(dev->rx_handler);
5187 }
5188 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5189 
5190 /**
5191  *	netdev_rx_handler_register - register receive handler
5192  *	@dev: device to register a handler for
5193  *	@rx_handler: receive handler to register
5194  *	@rx_handler_data: data pointer that is used by rx handler
5195  *
5196  *	Register a receive handler for a device. This handler will then be
5197  *	called from __netif_receive_skb. A negative errno code is returned
5198  *	on a failure.
5199  *
5200  *	The caller must hold the rtnl_mutex.
5201  *
5202  *	For a general description of rx_handler, see enum rx_handler_result.
5203  */
5204 int netdev_rx_handler_register(struct net_device *dev,
5205 			       rx_handler_func_t *rx_handler,
5206 			       void *rx_handler_data)
5207 {
5208 	if (netdev_is_rx_handler_busy(dev))
5209 		return -EBUSY;
5210 
5211 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5212 		return -EINVAL;
5213 
5214 	/* Note: rx_handler_data must be set before rx_handler */
5215 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5216 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5217 
5218 	return 0;
5219 }
5220 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5221 
5222 /**
5223  *	netdev_rx_handler_unregister - unregister receive handler
5224  *	@dev: device to unregister a handler from
5225  *
5226  *	Unregister a receive handler from a device.
5227  *
5228  *	The caller must hold the rtnl_mutex.
5229  */
5230 void netdev_rx_handler_unregister(struct net_device *dev)
5231 {
5232 
5233 	ASSERT_RTNL();
5234 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5235 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5236 	 * section has a guarantee to see a non NULL rx_handler_data
5237 	 * as well.
5238 	 */
5239 	synchronize_net();
5240 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5241 }
5242 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5243 
5244 /*
5245  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5246  * the special handling of PFMEMALLOC skbs.
5247  */
5248 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5249 {
5250 	switch (skb->protocol) {
5251 	case htons(ETH_P_ARP):
5252 	case htons(ETH_P_IP):
5253 	case htons(ETH_P_IPV6):
5254 	case htons(ETH_P_8021Q):
5255 	case htons(ETH_P_8021AD):
5256 		return true;
5257 	default:
5258 		return false;
5259 	}
5260 }
5261 
5262 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5263 			     int *ret, struct net_device *orig_dev)
5264 {
5265 	if (nf_hook_ingress_active(skb)) {
5266 		int ingress_retval;
5267 
5268 		if (*pt_prev) {
5269 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5270 			*pt_prev = NULL;
5271 		}
5272 
5273 		rcu_read_lock();
5274 		ingress_retval = nf_hook_ingress(skb);
5275 		rcu_read_unlock();
5276 		return ingress_retval;
5277 	}
5278 	return 0;
5279 }
5280 
5281 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5282 				    struct packet_type **ppt_prev)
5283 {
5284 	struct packet_type *ptype, *pt_prev;
5285 	rx_handler_func_t *rx_handler;
5286 	struct sk_buff *skb = *pskb;
5287 	struct net_device *orig_dev;
5288 	bool deliver_exact = false;
5289 	int ret = NET_RX_DROP;
5290 	__be16 type;
5291 
5292 	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5293 
5294 	trace_netif_receive_skb(skb);
5295 
5296 	orig_dev = skb->dev;
5297 
5298 	skb_reset_network_header(skb);
5299 	if (!skb_transport_header_was_set(skb))
5300 		skb_reset_transport_header(skb);
5301 	skb_reset_mac_len(skb);
5302 
5303 	pt_prev = NULL;
5304 
5305 another_round:
5306 	skb->skb_iif = skb->dev->ifindex;
5307 
5308 	__this_cpu_inc(softnet_data.processed);
5309 
5310 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5311 		int ret2;
5312 
5313 		migrate_disable();
5314 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5315 		migrate_enable();
5316 
5317 		if (ret2 != XDP_PASS) {
5318 			ret = NET_RX_DROP;
5319 			goto out;
5320 		}
5321 	}
5322 
5323 	if (eth_type_vlan(skb->protocol)) {
5324 		skb = skb_vlan_untag(skb);
5325 		if (unlikely(!skb))
5326 			goto out;
5327 	}
5328 
5329 	if (skb_skip_tc_classify(skb))
5330 		goto skip_classify;
5331 
5332 	if (pfmemalloc)
5333 		goto skip_taps;
5334 
5335 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
5336 		if (pt_prev)
5337 			ret = deliver_skb(skb, pt_prev, orig_dev);
5338 		pt_prev = ptype;
5339 	}
5340 
5341 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5342 		if (pt_prev)
5343 			ret = deliver_skb(skb, pt_prev, orig_dev);
5344 		pt_prev = ptype;
5345 	}
5346 
5347 skip_taps:
5348 #ifdef CONFIG_NET_INGRESS
5349 	if (static_branch_unlikely(&ingress_needed_key)) {
5350 		bool another = false;
5351 
5352 		nf_skip_egress(skb, true);
5353 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5354 					 &another);
5355 		if (another)
5356 			goto another_round;
5357 		if (!skb)
5358 			goto out;
5359 
5360 		nf_skip_egress(skb, false);
5361 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5362 			goto out;
5363 	}
5364 #endif
5365 	skb_reset_redirect(skb);
5366 skip_classify:
5367 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5368 		goto drop;
5369 
5370 	if (skb_vlan_tag_present(skb)) {
5371 		if (pt_prev) {
5372 			ret = deliver_skb(skb, pt_prev, orig_dev);
5373 			pt_prev = NULL;
5374 		}
5375 		if (vlan_do_receive(&skb))
5376 			goto another_round;
5377 		else if (unlikely(!skb))
5378 			goto out;
5379 	}
5380 
5381 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5382 	if (rx_handler) {
5383 		if (pt_prev) {
5384 			ret = deliver_skb(skb, pt_prev, orig_dev);
5385 			pt_prev = NULL;
5386 		}
5387 		switch (rx_handler(&skb)) {
5388 		case RX_HANDLER_CONSUMED:
5389 			ret = NET_RX_SUCCESS;
5390 			goto out;
5391 		case RX_HANDLER_ANOTHER:
5392 			goto another_round;
5393 		case RX_HANDLER_EXACT:
5394 			deliver_exact = true;
5395 			break;
5396 		case RX_HANDLER_PASS:
5397 			break;
5398 		default:
5399 			BUG();
5400 		}
5401 	}
5402 
5403 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5404 check_vlan_id:
5405 		if (skb_vlan_tag_get_id(skb)) {
5406 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5407 			 * find vlan device.
5408 			 */
5409 			skb->pkt_type = PACKET_OTHERHOST;
5410 		} else if (eth_type_vlan(skb->protocol)) {
5411 			/* Outer header is 802.1P with vlan 0, inner header is
5412 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5413 			 * not find vlan dev for vlan id 0.
5414 			 */
5415 			__vlan_hwaccel_clear_tag(skb);
5416 			skb = skb_vlan_untag(skb);
5417 			if (unlikely(!skb))
5418 				goto out;
5419 			if (vlan_do_receive(&skb))
5420 				/* After stripping off 802.1P header with vlan 0
5421 				 * vlan dev is found for inner header.
5422 				 */
5423 				goto another_round;
5424 			else if (unlikely(!skb))
5425 				goto out;
5426 			else
5427 				/* We have stripped outer 802.1P vlan 0 header.
5428 				 * But could not find vlan dev.
5429 				 * check again for vlan id to set OTHERHOST.
5430 				 */
5431 				goto check_vlan_id;
5432 		}
5433 		/* Note: we might in the future use prio bits
5434 		 * and set skb->priority like in vlan_do_receive()
5435 		 * For the time being, just ignore Priority Code Point
5436 		 */
5437 		__vlan_hwaccel_clear_tag(skb);
5438 	}
5439 
5440 	type = skb->protocol;
5441 
5442 	/* deliver only exact match when indicated */
5443 	if (likely(!deliver_exact)) {
5444 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5445 				       &ptype_base[ntohs(type) &
5446 						   PTYPE_HASH_MASK]);
5447 	}
5448 
5449 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5450 			       &orig_dev->ptype_specific);
5451 
5452 	if (unlikely(skb->dev != orig_dev)) {
5453 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5454 				       &skb->dev->ptype_specific);
5455 	}
5456 
5457 	if (pt_prev) {
5458 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5459 			goto drop;
5460 		*ppt_prev = pt_prev;
5461 	} else {
5462 drop:
5463 		if (!deliver_exact)
5464 			dev_core_stats_rx_dropped_inc(skb->dev);
5465 		else
5466 			dev_core_stats_rx_nohandler_inc(skb->dev);
5467 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5468 		/* Jamal, now you will not able to escape explaining
5469 		 * me how you were going to use this. :-)
5470 		 */
5471 		ret = NET_RX_DROP;
5472 	}
5473 
5474 out:
5475 	/* The invariant here is that if *ppt_prev is not NULL
5476 	 * then skb should also be non-NULL.
5477 	 *
5478 	 * Apparently *ppt_prev assignment above holds this invariant due to
5479 	 * skb dereferencing near it.
5480 	 */
5481 	*pskb = skb;
5482 	return ret;
5483 }
5484 
5485 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5486 {
5487 	struct net_device *orig_dev = skb->dev;
5488 	struct packet_type *pt_prev = NULL;
5489 	int ret;
5490 
5491 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5492 	if (pt_prev)
5493 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5494 					 skb->dev, pt_prev, orig_dev);
5495 	return ret;
5496 }
5497 
5498 /**
5499  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5500  *	@skb: buffer to process
5501  *
5502  *	More direct receive version of netif_receive_skb().  It should
5503  *	only be used by callers that have a need to skip RPS and Generic XDP.
5504  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5505  *
5506  *	This function may only be called from softirq context and interrupts
5507  *	should be enabled.
5508  *
5509  *	Return values (usually ignored):
5510  *	NET_RX_SUCCESS: no congestion
5511  *	NET_RX_DROP: packet was dropped
5512  */
5513 int netif_receive_skb_core(struct sk_buff *skb)
5514 {
5515 	int ret;
5516 
5517 	rcu_read_lock();
5518 	ret = __netif_receive_skb_one_core(skb, false);
5519 	rcu_read_unlock();
5520 
5521 	return ret;
5522 }
5523 EXPORT_SYMBOL(netif_receive_skb_core);
5524 
5525 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5526 						  struct packet_type *pt_prev,
5527 						  struct net_device *orig_dev)
5528 {
5529 	struct sk_buff *skb, *next;
5530 
5531 	if (!pt_prev)
5532 		return;
5533 	if (list_empty(head))
5534 		return;
5535 	if (pt_prev->list_func != NULL)
5536 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5537 				   ip_list_rcv, head, pt_prev, orig_dev);
5538 	else
5539 		list_for_each_entry_safe(skb, next, head, list) {
5540 			skb_list_del_init(skb);
5541 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5542 		}
5543 }
5544 
5545 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5546 {
5547 	/* Fast-path assumptions:
5548 	 * - There is no RX handler.
5549 	 * - Only one packet_type matches.
5550 	 * If either of these fails, we will end up doing some per-packet
5551 	 * processing in-line, then handling the 'last ptype' for the whole
5552 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5553 	 * because the 'last ptype' must be constant across the sublist, and all
5554 	 * other ptypes are handled per-packet.
5555 	 */
5556 	/* Current (common) ptype of sublist */
5557 	struct packet_type *pt_curr = NULL;
5558 	/* Current (common) orig_dev of sublist */
5559 	struct net_device *od_curr = NULL;
5560 	struct list_head sublist;
5561 	struct sk_buff *skb, *next;
5562 
5563 	INIT_LIST_HEAD(&sublist);
5564 	list_for_each_entry_safe(skb, next, head, list) {
5565 		struct net_device *orig_dev = skb->dev;
5566 		struct packet_type *pt_prev = NULL;
5567 
5568 		skb_list_del_init(skb);
5569 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5570 		if (!pt_prev)
5571 			continue;
5572 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5573 			/* dispatch old sublist */
5574 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5575 			/* start new sublist */
5576 			INIT_LIST_HEAD(&sublist);
5577 			pt_curr = pt_prev;
5578 			od_curr = orig_dev;
5579 		}
5580 		list_add_tail(&skb->list, &sublist);
5581 	}
5582 
5583 	/* dispatch final sublist */
5584 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5585 }
5586 
5587 static int __netif_receive_skb(struct sk_buff *skb)
5588 {
5589 	int ret;
5590 
5591 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5592 		unsigned int noreclaim_flag;
5593 
5594 		/*
5595 		 * PFMEMALLOC skbs are special, they should
5596 		 * - be delivered to SOCK_MEMALLOC sockets only
5597 		 * - stay away from userspace
5598 		 * - have bounded memory usage
5599 		 *
5600 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5601 		 * context down to all allocation sites.
5602 		 */
5603 		noreclaim_flag = memalloc_noreclaim_save();
5604 		ret = __netif_receive_skb_one_core(skb, true);
5605 		memalloc_noreclaim_restore(noreclaim_flag);
5606 	} else
5607 		ret = __netif_receive_skb_one_core(skb, false);
5608 
5609 	return ret;
5610 }
5611 
5612 static void __netif_receive_skb_list(struct list_head *head)
5613 {
5614 	unsigned long noreclaim_flag = 0;
5615 	struct sk_buff *skb, *next;
5616 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5617 
5618 	list_for_each_entry_safe(skb, next, head, list) {
5619 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5620 			struct list_head sublist;
5621 
5622 			/* Handle the previous sublist */
5623 			list_cut_before(&sublist, head, &skb->list);
5624 			if (!list_empty(&sublist))
5625 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5626 			pfmemalloc = !pfmemalloc;
5627 			/* See comments in __netif_receive_skb */
5628 			if (pfmemalloc)
5629 				noreclaim_flag = memalloc_noreclaim_save();
5630 			else
5631 				memalloc_noreclaim_restore(noreclaim_flag);
5632 		}
5633 	}
5634 	/* Handle the remaining sublist */
5635 	if (!list_empty(head))
5636 		__netif_receive_skb_list_core(head, pfmemalloc);
5637 	/* Restore pflags */
5638 	if (pfmemalloc)
5639 		memalloc_noreclaim_restore(noreclaim_flag);
5640 }
5641 
5642 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5643 {
5644 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5645 	struct bpf_prog *new = xdp->prog;
5646 	int ret = 0;
5647 
5648 	switch (xdp->command) {
5649 	case XDP_SETUP_PROG:
5650 		rcu_assign_pointer(dev->xdp_prog, new);
5651 		if (old)
5652 			bpf_prog_put(old);
5653 
5654 		if (old && !new) {
5655 			static_branch_dec(&generic_xdp_needed_key);
5656 		} else if (new && !old) {
5657 			static_branch_inc(&generic_xdp_needed_key);
5658 			dev_disable_lro(dev);
5659 			dev_disable_gro_hw(dev);
5660 		}
5661 		break;
5662 
5663 	default:
5664 		ret = -EINVAL;
5665 		break;
5666 	}
5667 
5668 	return ret;
5669 }
5670 
5671 static int netif_receive_skb_internal(struct sk_buff *skb)
5672 {
5673 	int ret;
5674 
5675 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5676 
5677 	if (skb_defer_rx_timestamp(skb))
5678 		return NET_RX_SUCCESS;
5679 
5680 	rcu_read_lock();
5681 #ifdef CONFIG_RPS
5682 	if (static_branch_unlikely(&rps_needed)) {
5683 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5684 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5685 
5686 		if (cpu >= 0) {
5687 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5688 			rcu_read_unlock();
5689 			return ret;
5690 		}
5691 	}
5692 #endif
5693 	ret = __netif_receive_skb(skb);
5694 	rcu_read_unlock();
5695 	return ret;
5696 }
5697 
5698 void netif_receive_skb_list_internal(struct list_head *head)
5699 {
5700 	struct sk_buff *skb, *next;
5701 	struct list_head sublist;
5702 
5703 	INIT_LIST_HEAD(&sublist);
5704 	list_for_each_entry_safe(skb, next, head, list) {
5705 		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5706 		skb_list_del_init(skb);
5707 		if (!skb_defer_rx_timestamp(skb))
5708 			list_add_tail(&skb->list, &sublist);
5709 	}
5710 	list_splice_init(&sublist, head);
5711 
5712 	rcu_read_lock();
5713 #ifdef CONFIG_RPS
5714 	if (static_branch_unlikely(&rps_needed)) {
5715 		list_for_each_entry_safe(skb, next, head, list) {
5716 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5717 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5718 
5719 			if (cpu >= 0) {
5720 				/* Will be handled, remove from list */
5721 				skb_list_del_init(skb);
5722 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5723 			}
5724 		}
5725 	}
5726 #endif
5727 	__netif_receive_skb_list(head);
5728 	rcu_read_unlock();
5729 }
5730 
5731 /**
5732  *	netif_receive_skb - process receive buffer from network
5733  *	@skb: buffer to process
5734  *
5735  *	netif_receive_skb() is the main receive data processing function.
5736  *	It always succeeds. The buffer may be dropped during processing
5737  *	for congestion control or by the protocol layers.
5738  *
5739  *	This function may only be called from softirq context and interrupts
5740  *	should be enabled.
5741  *
5742  *	Return values (usually ignored):
5743  *	NET_RX_SUCCESS: no congestion
5744  *	NET_RX_DROP: packet was dropped
5745  */
5746 int netif_receive_skb(struct sk_buff *skb)
5747 {
5748 	int ret;
5749 
5750 	trace_netif_receive_skb_entry(skb);
5751 
5752 	ret = netif_receive_skb_internal(skb);
5753 	trace_netif_receive_skb_exit(ret);
5754 
5755 	return ret;
5756 }
5757 EXPORT_SYMBOL(netif_receive_skb);
5758 
5759 /**
5760  *	netif_receive_skb_list - process many receive buffers from network
5761  *	@head: list of skbs to process.
5762  *
5763  *	Since return value of netif_receive_skb() is normally ignored, and
5764  *	wouldn't be meaningful for a list, this function returns void.
5765  *
5766  *	This function may only be called from softirq context and interrupts
5767  *	should be enabled.
5768  */
5769 void netif_receive_skb_list(struct list_head *head)
5770 {
5771 	struct sk_buff *skb;
5772 
5773 	if (list_empty(head))
5774 		return;
5775 	if (trace_netif_receive_skb_list_entry_enabled()) {
5776 		list_for_each_entry(skb, head, list)
5777 			trace_netif_receive_skb_list_entry(skb);
5778 	}
5779 	netif_receive_skb_list_internal(head);
5780 	trace_netif_receive_skb_list_exit(0);
5781 }
5782 EXPORT_SYMBOL(netif_receive_skb_list);
5783 
5784 static DEFINE_PER_CPU(struct work_struct, flush_works);
5785 
5786 /* Network device is going away, flush any packets still pending */
5787 static void flush_backlog(struct work_struct *work)
5788 {
5789 	struct sk_buff *skb, *tmp;
5790 	struct softnet_data *sd;
5791 
5792 	local_bh_disable();
5793 	sd = this_cpu_ptr(&softnet_data);
5794 
5795 	rps_lock_irq_disable(sd);
5796 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5797 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5798 			__skb_unlink(skb, &sd->input_pkt_queue);
5799 			dev_kfree_skb_irq(skb);
5800 			input_queue_head_incr(sd);
5801 		}
5802 	}
5803 	rps_unlock_irq_enable(sd);
5804 
5805 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5806 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5807 			__skb_unlink(skb, &sd->process_queue);
5808 			kfree_skb(skb);
5809 			input_queue_head_incr(sd);
5810 		}
5811 	}
5812 	local_bh_enable();
5813 }
5814 
5815 static bool flush_required(int cpu)
5816 {
5817 #if IS_ENABLED(CONFIG_RPS)
5818 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5819 	bool do_flush;
5820 
5821 	rps_lock_irq_disable(sd);
5822 
5823 	/* as insertion into process_queue happens with the rps lock held,
5824 	 * process_queue access may race only with dequeue
5825 	 */
5826 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5827 		   !skb_queue_empty_lockless(&sd->process_queue);
5828 	rps_unlock_irq_enable(sd);
5829 
5830 	return do_flush;
5831 #endif
5832 	/* without RPS we can't safely check input_pkt_queue: during a
5833 	 * concurrent remote skb_queue_splice() we can detect as empty both
5834 	 * input_pkt_queue and process_queue even if the latter could end-up
5835 	 * containing a lot of packets.
5836 	 */
5837 	return true;
5838 }
5839 
5840 static void flush_all_backlogs(void)
5841 {
5842 	static cpumask_t flush_cpus;
5843 	unsigned int cpu;
5844 
5845 	/* since we are under rtnl lock protection we can use static data
5846 	 * for the cpumask and avoid allocating on stack the possibly
5847 	 * large mask
5848 	 */
5849 	ASSERT_RTNL();
5850 
5851 	cpus_read_lock();
5852 
5853 	cpumask_clear(&flush_cpus);
5854 	for_each_online_cpu(cpu) {
5855 		if (flush_required(cpu)) {
5856 			queue_work_on(cpu, system_highpri_wq,
5857 				      per_cpu_ptr(&flush_works, cpu));
5858 			cpumask_set_cpu(cpu, &flush_cpus);
5859 		}
5860 	}
5861 
5862 	/* we can have in flight packet[s] on the cpus we are not flushing,
5863 	 * synchronize_net() in unregister_netdevice_many() will take care of
5864 	 * them
5865 	 */
5866 	for_each_cpu(cpu, &flush_cpus)
5867 		flush_work(per_cpu_ptr(&flush_works, cpu));
5868 
5869 	cpus_read_unlock();
5870 }
5871 
5872 static void net_rps_send_ipi(struct softnet_data *remsd)
5873 {
5874 #ifdef CONFIG_RPS
5875 	while (remsd) {
5876 		struct softnet_data *next = remsd->rps_ipi_next;
5877 
5878 		if (cpu_online(remsd->cpu))
5879 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
5880 		remsd = next;
5881 	}
5882 #endif
5883 }
5884 
5885 /*
5886  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5887  * Note: called with local irq disabled, but exits with local irq enabled.
5888  */
5889 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5890 {
5891 #ifdef CONFIG_RPS
5892 	struct softnet_data *remsd = sd->rps_ipi_list;
5893 
5894 	if (remsd) {
5895 		sd->rps_ipi_list = NULL;
5896 
5897 		local_irq_enable();
5898 
5899 		/* Send pending IPI's to kick RPS processing on remote cpus. */
5900 		net_rps_send_ipi(remsd);
5901 	} else
5902 #endif
5903 		local_irq_enable();
5904 }
5905 
5906 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5907 {
5908 #ifdef CONFIG_RPS
5909 	return sd->rps_ipi_list != NULL;
5910 #else
5911 	return false;
5912 #endif
5913 }
5914 
5915 static int process_backlog(struct napi_struct *napi, int quota)
5916 {
5917 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5918 	bool again = true;
5919 	int work = 0;
5920 
5921 	/* Check if we have pending ipi, its better to send them now,
5922 	 * not waiting net_rx_action() end.
5923 	 */
5924 	if (sd_has_rps_ipi_waiting(sd)) {
5925 		local_irq_disable();
5926 		net_rps_action_and_irq_enable(sd);
5927 	}
5928 
5929 	napi->weight = READ_ONCE(dev_rx_weight);
5930 	while (again) {
5931 		struct sk_buff *skb;
5932 
5933 		while ((skb = __skb_dequeue(&sd->process_queue))) {
5934 			rcu_read_lock();
5935 			__netif_receive_skb(skb);
5936 			rcu_read_unlock();
5937 			input_queue_head_incr(sd);
5938 			if (++work >= quota)
5939 				return work;
5940 
5941 		}
5942 
5943 		rps_lock_irq_disable(sd);
5944 		if (skb_queue_empty(&sd->input_pkt_queue)) {
5945 			/*
5946 			 * Inline a custom version of __napi_complete().
5947 			 * only current cpu owns and manipulates this napi,
5948 			 * and NAPI_STATE_SCHED is the only possible flag set
5949 			 * on backlog.
5950 			 * We can use a plain write instead of clear_bit(),
5951 			 * and we dont need an smp_mb() memory barrier.
5952 			 */
5953 			napi->state = 0;
5954 			again = false;
5955 		} else {
5956 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
5957 						   &sd->process_queue);
5958 		}
5959 		rps_unlock_irq_enable(sd);
5960 	}
5961 
5962 	return work;
5963 }
5964 
5965 /**
5966  * __napi_schedule - schedule for receive
5967  * @n: entry to schedule
5968  *
5969  * The entry's receive function will be scheduled to run.
5970  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5971  */
5972 void __napi_schedule(struct napi_struct *n)
5973 {
5974 	unsigned long flags;
5975 
5976 	local_irq_save(flags);
5977 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
5978 	local_irq_restore(flags);
5979 }
5980 EXPORT_SYMBOL(__napi_schedule);
5981 
5982 /**
5983  *	napi_schedule_prep - check if napi can be scheduled
5984  *	@n: napi context
5985  *
5986  * Test if NAPI routine is already running, and if not mark
5987  * it as running.  This is used as a condition variable to
5988  * insure only one NAPI poll instance runs.  We also make
5989  * sure there is no pending NAPI disable.
5990  */
5991 bool napi_schedule_prep(struct napi_struct *n)
5992 {
5993 	unsigned long new, val = READ_ONCE(n->state);
5994 
5995 	do {
5996 		if (unlikely(val & NAPIF_STATE_DISABLE))
5997 			return false;
5998 		new = val | NAPIF_STATE_SCHED;
5999 
6000 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
6001 		 * This was suggested by Alexander Duyck, as compiler
6002 		 * emits better code than :
6003 		 * if (val & NAPIF_STATE_SCHED)
6004 		 *     new |= NAPIF_STATE_MISSED;
6005 		 */
6006 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6007 						   NAPIF_STATE_MISSED;
6008 	} while (!try_cmpxchg(&n->state, &val, new));
6009 
6010 	return !(val & NAPIF_STATE_SCHED);
6011 }
6012 EXPORT_SYMBOL(napi_schedule_prep);
6013 
6014 /**
6015  * __napi_schedule_irqoff - schedule for receive
6016  * @n: entry to schedule
6017  *
6018  * Variant of __napi_schedule() assuming hard irqs are masked.
6019  *
6020  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6021  * because the interrupt disabled assumption might not be true
6022  * due to force-threaded interrupts and spinlock substitution.
6023  */
6024 void __napi_schedule_irqoff(struct napi_struct *n)
6025 {
6026 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6027 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6028 	else
6029 		__napi_schedule(n);
6030 }
6031 EXPORT_SYMBOL(__napi_schedule_irqoff);
6032 
6033 bool napi_complete_done(struct napi_struct *n, int work_done)
6034 {
6035 	unsigned long flags, val, new, timeout = 0;
6036 	bool ret = true;
6037 
6038 	/*
6039 	 * 1) Don't let napi dequeue from the cpu poll list
6040 	 *    just in case its running on a different cpu.
6041 	 * 2) If we are busy polling, do nothing here, we have
6042 	 *    the guarantee we will be called later.
6043 	 */
6044 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6045 				 NAPIF_STATE_IN_BUSY_POLL)))
6046 		return false;
6047 
6048 	if (work_done) {
6049 		if (n->gro_bitmask)
6050 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6051 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6052 	}
6053 	if (n->defer_hard_irqs_count > 0) {
6054 		n->defer_hard_irqs_count--;
6055 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6056 		if (timeout)
6057 			ret = false;
6058 	}
6059 	if (n->gro_bitmask) {
6060 		/* When the NAPI instance uses a timeout and keeps postponing
6061 		 * it, we need to bound somehow the time packets are kept in
6062 		 * the GRO layer
6063 		 */
6064 		napi_gro_flush(n, !!timeout);
6065 	}
6066 
6067 	gro_normal_list(n);
6068 
6069 	if (unlikely(!list_empty(&n->poll_list))) {
6070 		/* If n->poll_list is not empty, we need to mask irqs */
6071 		local_irq_save(flags);
6072 		list_del_init(&n->poll_list);
6073 		local_irq_restore(flags);
6074 	}
6075 	WRITE_ONCE(n->list_owner, -1);
6076 
6077 	val = READ_ONCE(n->state);
6078 	do {
6079 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6080 
6081 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6082 			      NAPIF_STATE_SCHED_THREADED |
6083 			      NAPIF_STATE_PREFER_BUSY_POLL);
6084 
6085 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6086 		 * because we will call napi->poll() one more time.
6087 		 * This C code was suggested by Alexander Duyck to help gcc.
6088 		 */
6089 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6090 						    NAPIF_STATE_SCHED;
6091 	} while (!try_cmpxchg(&n->state, &val, new));
6092 
6093 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6094 		__napi_schedule(n);
6095 		return false;
6096 	}
6097 
6098 	if (timeout)
6099 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6100 			      HRTIMER_MODE_REL_PINNED);
6101 	return ret;
6102 }
6103 EXPORT_SYMBOL(napi_complete_done);
6104 
6105 /* must be called under rcu_read_lock(), as we dont take a reference */
6106 static struct napi_struct *napi_by_id(unsigned int napi_id)
6107 {
6108 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6109 	struct napi_struct *napi;
6110 
6111 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6112 		if (napi->napi_id == napi_id)
6113 			return napi;
6114 
6115 	return NULL;
6116 }
6117 
6118 #if defined(CONFIG_NET_RX_BUSY_POLL)
6119 
6120 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6121 {
6122 	if (!skip_schedule) {
6123 		gro_normal_list(napi);
6124 		__napi_schedule(napi);
6125 		return;
6126 	}
6127 
6128 	if (napi->gro_bitmask) {
6129 		/* flush too old packets
6130 		 * If HZ < 1000, flush all packets.
6131 		 */
6132 		napi_gro_flush(napi, HZ >= 1000);
6133 	}
6134 
6135 	gro_normal_list(napi);
6136 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6137 }
6138 
6139 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6140 			   u16 budget)
6141 {
6142 	bool skip_schedule = false;
6143 	unsigned long timeout;
6144 	int rc;
6145 
6146 	/* Busy polling means there is a high chance device driver hard irq
6147 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6148 	 * set in napi_schedule_prep().
6149 	 * Since we are about to call napi->poll() once more, we can safely
6150 	 * clear NAPI_STATE_MISSED.
6151 	 *
6152 	 * Note: x86 could use a single "lock and ..." instruction
6153 	 * to perform these two clear_bit()
6154 	 */
6155 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6156 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6157 
6158 	local_bh_disable();
6159 
6160 	if (prefer_busy_poll) {
6161 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6162 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6163 		if (napi->defer_hard_irqs_count && timeout) {
6164 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6165 			skip_schedule = true;
6166 		}
6167 	}
6168 
6169 	/* All we really want here is to re-enable device interrupts.
6170 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6171 	 */
6172 	rc = napi->poll(napi, budget);
6173 	/* We can't gro_normal_list() here, because napi->poll() might have
6174 	 * rearmed the napi (napi_complete_done()) in which case it could
6175 	 * already be running on another CPU.
6176 	 */
6177 	trace_napi_poll(napi, rc, budget);
6178 	netpoll_poll_unlock(have_poll_lock);
6179 	if (rc == budget)
6180 		__busy_poll_stop(napi, skip_schedule);
6181 	local_bh_enable();
6182 }
6183 
6184 void napi_busy_loop(unsigned int napi_id,
6185 		    bool (*loop_end)(void *, unsigned long),
6186 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6187 {
6188 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6189 	int (*napi_poll)(struct napi_struct *napi, int budget);
6190 	void *have_poll_lock = NULL;
6191 	struct napi_struct *napi;
6192 
6193 restart:
6194 	napi_poll = NULL;
6195 
6196 	rcu_read_lock();
6197 
6198 	napi = napi_by_id(napi_id);
6199 	if (!napi)
6200 		goto out;
6201 
6202 	preempt_disable();
6203 	for (;;) {
6204 		int work = 0;
6205 
6206 		local_bh_disable();
6207 		if (!napi_poll) {
6208 			unsigned long val = READ_ONCE(napi->state);
6209 
6210 			/* If multiple threads are competing for this napi,
6211 			 * we avoid dirtying napi->state as much as we can.
6212 			 */
6213 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6214 				   NAPIF_STATE_IN_BUSY_POLL)) {
6215 				if (prefer_busy_poll)
6216 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6217 				goto count;
6218 			}
6219 			if (cmpxchg(&napi->state, val,
6220 				    val | NAPIF_STATE_IN_BUSY_POLL |
6221 					  NAPIF_STATE_SCHED) != val) {
6222 				if (prefer_busy_poll)
6223 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6224 				goto count;
6225 			}
6226 			have_poll_lock = netpoll_poll_lock(napi);
6227 			napi_poll = napi->poll;
6228 		}
6229 		work = napi_poll(napi, budget);
6230 		trace_napi_poll(napi, work, budget);
6231 		gro_normal_list(napi);
6232 count:
6233 		if (work > 0)
6234 			__NET_ADD_STATS(dev_net(napi->dev),
6235 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6236 		local_bh_enable();
6237 
6238 		if (!loop_end || loop_end(loop_end_arg, start_time))
6239 			break;
6240 
6241 		if (unlikely(need_resched())) {
6242 			if (napi_poll)
6243 				busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6244 			preempt_enable();
6245 			rcu_read_unlock();
6246 			cond_resched();
6247 			if (loop_end(loop_end_arg, start_time))
6248 				return;
6249 			goto restart;
6250 		}
6251 		cpu_relax();
6252 	}
6253 	if (napi_poll)
6254 		busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6255 	preempt_enable();
6256 out:
6257 	rcu_read_unlock();
6258 }
6259 EXPORT_SYMBOL(napi_busy_loop);
6260 
6261 #endif /* CONFIG_NET_RX_BUSY_POLL */
6262 
6263 static void napi_hash_add(struct napi_struct *napi)
6264 {
6265 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6266 		return;
6267 
6268 	spin_lock(&napi_hash_lock);
6269 
6270 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6271 	do {
6272 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6273 			napi_gen_id = MIN_NAPI_ID;
6274 	} while (napi_by_id(napi_gen_id));
6275 	napi->napi_id = napi_gen_id;
6276 
6277 	hlist_add_head_rcu(&napi->napi_hash_node,
6278 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6279 
6280 	spin_unlock(&napi_hash_lock);
6281 }
6282 
6283 /* Warning : caller is responsible to make sure rcu grace period
6284  * is respected before freeing memory containing @napi
6285  */
6286 static void napi_hash_del(struct napi_struct *napi)
6287 {
6288 	spin_lock(&napi_hash_lock);
6289 
6290 	hlist_del_init_rcu(&napi->napi_hash_node);
6291 
6292 	spin_unlock(&napi_hash_lock);
6293 }
6294 
6295 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6296 {
6297 	struct napi_struct *napi;
6298 
6299 	napi = container_of(timer, struct napi_struct, timer);
6300 
6301 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6302 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6303 	 */
6304 	if (!napi_disable_pending(napi) &&
6305 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6306 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6307 		__napi_schedule_irqoff(napi);
6308 	}
6309 
6310 	return HRTIMER_NORESTART;
6311 }
6312 
6313 static void init_gro_hash(struct napi_struct *napi)
6314 {
6315 	int i;
6316 
6317 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6318 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6319 		napi->gro_hash[i].count = 0;
6320 	}
6321 	napi->gro_bitmask = 0;
6322 }
6323 
6324 int dev_set_threaded(struct net_device *dev, bool threaded)
6325 {
6326 	struct napi_struct *napi;
6327 	int err = 0;
6328 
6329 	if (dev->threaded == threaded)
6330 		return 0;
6331 
6332 	if (threaded) {
6333 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6334 			if (!napi->thread) {
6335 				err = napi_kthread_create(napi);
6336 				if (err) {
6337 					threaded = false;
6338 					break;
6339 				}
6340 			}
6341 		}
6342 	}
6343 
6344 	dev->threaded = threaded;
6345 
6346 	/* Make sure kthread is created before THREADED bit
6347 	 * is set.
6348 	 */
6349 	smp_mb__before_atomic();
6350 
6351 	/* Setting/unsetting threaded mode on a napi might not immediately
6352 	 * take effect, if the current napi instance is actively being
6353 	 * polled. In this case, the switch between threaded mode and
6354 	 * softirq mode will happen in the next round of napi_schedule().
6355 	 * This should not cause hiccups/stalls to the live traffic.
6356 	 */
6357 	list_for_each_entry(napi, &dev->napi_list, dev_list) {
6358 		if (threaded)
6359 			set_bit(NAPI_STATE_THREADED, &napi->state);
6360 		else
6361 			clear_bit(NAPI_STATE_THREADED, &napi->state);
6362 	}
6363 
6364 	return err;
6365 }
6366 EXPORT_SYMBOL(dev_set_threaded);
6367 
6368 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6369 			   int (*poll)(struct napi_struct *, int), int weight)
6370 {
6371 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6372 		return;
6373 
6374 	INIT_LIST_HEAD(&napi->poll_list);
6375 	INIT_HLIST_NODE(&napi->napi_hash_node);
6376 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6377 	napi->timer.function = napi_watchdog;
6378 	init_gro_hash(napi);
6379 	napi->skb = NULL;
6380 	INIT_LIST_HEAD(&napi->rx_list);
6381 	napi->rx_count = 0;
6382 	napi->poll = poll;
6383 	if (weight > NAPI_POLL_WEIGHT)
6384 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6385 				weight);
6386 	napi->weight = weight;
6387 	napi->dev = dev;
6388 #ifdef CONFIG_NETPOLL
6389 	napi->poll_owner = -1;
6390 #endif
6391 	napi->list_owner = -1;
6392 	set_bit(NAPI_STATE_SCHED, &napi->state);
6393 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6394 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6395 	napi_hash_add(napi);
6396 	napi_get_frags_check(napi);
6397 	/* Create kthread for this napi if dev->threaded is set.
6398 	 * Clear dev->threaded if kthread creation failed so that
6399 	 * threaded mode will not be enabled in napi_enable().
6400 	 */
6401 	if (dev->threaded && napi_kthread_create(napi))
6402 		dev->threaded = 0;
6403 }
6404 EXPORT_SYMBOL(netif_napi_add_weight);
6405 
6406 void napi_disable(struct napi_struct *n)
6407 {
6408 	unsigned long val, new;
6409 
6410 	might_sleep();
6411 	set_bit(NAPI_STATE_DISABLE, &n->state);
6412 
6413 	val = READ_ONCE(n->state);
6414 	do {
6415 		while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6416 			usleep_range(20, 200);
6417 			val = READ_ONCE(n->state);
6418 		}
6419 
6420 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6421 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6422 	} while (!try_cmpxchg(&n->state, &val, new));
6423 
6424 	hrtimer_cancel(&n->timer);
6425 
6426 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6427 }
6428 EXPORT_SYMBOL(napi_disable);
6429 
6430 /**
6431  *	napi_enable - enable NAPI scheduling
6432  *	@n: NAPI context
6433  *
6434  * Resume NAPI from being scheduled on this context.
6435  * Must be paired with napi_disable.
6436  */
6437 void napi_enable(struct napi_struct *n)
6438 {
6439 	unsigned long new, val = READ_ONCE(n->state);
6440 
6441 	do {
6442 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6443 
6444 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6445 		if (n->dev->threaded && n->thread)
6446 			new |= NAPIF_STATE_THREADED;
6447 	} while (!try_cmpxchg(&n->state, &val, new));
6448 }
6449 EXPORT_SYMBOL(napi_enable);
6450 
6451 static void flush_gro_hash(struct napi_struct *napi)
6452 {
6453 	int i;
6454 
6455 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6456 		struct sk_buff *skb, *n;
6457 
6458 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6459 			kfree_skb(skb);
6460 		napi->gro_hash[i].count = 0;
6461 	}
6462 }
6463 
6464 /* Must be called in process context */
6465 void __netif_napi_del(struct napi_struct *napi)
6466 {
6467 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6468 		return;
6469 
6470 	napi_hash_del(napi);
6471 	list_del_rcu(&napi->dev_list);
6472 	napi_free_frags(napi);
6473 
6474 	flush_gro_hash(napi);
6475 	napi->gro_bitmask = 0;
6476 
6477 	if (napi->thread) {
6478 		kthread_stop(napi->thread);
6479 		napi->thread = NULL;
6480 	}
6481 }
6482 EXPORT_SYMBOL(__netif_napi_del);
6483 
6484 static int __napi_poll(struct napi_struct *n, bool *repoll)
6485 {
6486 	int work, weight;
6487 
6488 	weight = n->weight;
6489 
6490 	/* This NAPI_STATE_SCHED test is for avoiding a race
6491 	 * with netpoll's poll_napi().  Only the entity which
6492 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6493 	 * actually make the ->poll() call.  Therefore we avoid
6494 	 * accidentally calling ->poll() when NAPI is not scheduled.
6495 	 */
6496 	work = 0;
6497 	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6498 		work = n->poll(n, weight);
6499 		trace_napi_poll(n, work, weight);
6500 	}
6501 
6502 	if (unlikely(work > weight))
6503 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6504 				n->poll, work, weight);
6505 
6506 	if (likely(work < weight))
6507 		return work;
6508 
6509 	/* Drivers must not modify the NAPI state if they
6510 	 * consume the entire weight.  In such cases this code
6511 	 * still "owns" the NAPI instance and therefore can
6512 	 * move the instance around on the list at-will.
6513 	 */
6514 	if (unlikely(napi_disable_pending(n))) {
6515 		napi_complete(n);
6516 		return work;
6517 	}
6518 
6519 	/* The NAPI context has more processing work, but busy-polling
6520 	 * is preferred. Exit early.
6521 	 */
6522 	if (napi_prefer_busy_poll(n)) {
6523 		if (napi_complete_done(n, work)) {
6524 			/* If timeout is not set, we need to make sure
6525 			 * that the NAPI is re-scheduled.
6526 			 */
6527 			napi_schedule(n);
6528 		}
6529 		return work;
6530 	}
6531 
6532 	if (n->gro_bitmask) {
6533 		/* flush too old packets
6534 		 * If HZ < 1000, flush all packets.
6535 		 */
6536 		napi_gro_flush(n, HZ >= 1000);
6537 	}
6538 
6539 	gro_normal_list(n);
6540 
6541 	/* Some drivers may have called napi_schedule
6542 	 * prior to exhausting their budget.
6543 	 */
6544 	if (unlikely(!list_empty(&n->poll_list))) {
6545 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6546 			     n->dev ? n->dev->name : "backlog");
6547 		return work;
6548 	}
6549 
6550 	*repoll = true;
6551 
6552 	return work;
6553 }
6554 
6555 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6556 {
6557 	bool do_repoll = false;
6558 	void *have;
6559 	int work;
6560 
6561 	list_del_init(&n->poll_list);
6562 
6563 	have = netpoll_poll_lock(n);
6564 
6565 	work = __napi_poll(n, &do_repoll);
6566 
6567 	if (do_repoll)
6568 		list_add_tail(&n->poll_list, repoll);
6569 
6570 	netpoll_poll_unlock(have);
6571 
6572 	return work;
6573 }
6574 
6575 static int napi_thread_wait(struct napi_struct *napi)
6576 {
6577 	bool woken = false;
6578 
6579 	set_current_state(TASK_INTERRUPTIBLE);
6580 
6581 	while (!kthread_should_stop()) {
6582 		/* Testing SCHED_THREADED bit here to make sure the current
6583 		 * kthread owns this napi and could poll on this napi.
6584 		 * Testing SCHED bit is not enough because SCHED bit might be
6585 		 * set by some other busy poll thread or by napi_disable().
6586 		 */
6587 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6588 			WARN_ON(!list_empty(&napi->poll_list));
6589 			__set_current_state(TASK_RUNNING);
6590 			return 0;
6591 		}
6592 
6593 		schedule();
6594 		/* woken being true indicates this thread owns this napi. */
6595 		woken = true;
6596 		set_current_state(TASK_INTERRUPTIBLE);
6597 	}
6598 	__set_current_state(TASK_RUNNING);
6599 
6600 	return -1;
6601 }
6602 
6603 static void skb_defer_free_flush(struct softnet_data *sd)
6604 {
6605 	struct sk_buff *skb, *next;
6606 
6607 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6608 	if (!READ_ONCE(sd->defer_list))
6609 		return;
6610 
6611 	spin_lock(&sd->defer_lock);
6612 	skb = sd->defer_list;
6613 	sd->defer_list = NULL;
6614 	sd->defer_count = 0;
6615 	spin_unlock(&sd->defer_lock);
6616 
6617 	while (skb != NULL) {
6618 		next = skb->next;
6619 		napi_consume_skb(skb, 1);
6620 		skb = next;
6621 	}
6622 }
6623 
6624 static int napi_threaded_poll(void *data)
6625 {
6626 	struct napi_struct *napi = data;
6627 	struct softnet_data *sd;
6628 	void *have;
6629 
6630 	while (!napi_thread_wait(napi)) {
6631 		for (;;) {
6632 			bool repoll = false;
6633 
6634 			local_bh_disable();
6635 			sd = this_cpu_ptr(&softnet_data);
6636 			sd->in_napi_threaded_poll = true;
6637 
6638 			have = netpoll_poll_lock(napi);
6639 			__napi_poll(napi, &repoll);
6640 			netpoll_poll_unlock(have);
6641 
6642 			sd->in_napi_threaded_poll = false;
6643 			barrier();
6644 
6645 			if (sd_has_rps_ipi_waiting(sd)) {
6646 				local_irq_disable();
6647 				net_rps_action_and_irq_enable(sd);
6648 			}
6649 			skb_defer_free_flush(sd);
6650 			local_bh_enable();
6651 
6652 			if (!repoll)
6653 				break;
6654 
6655 			cond_resched();
6656 		}
6657 	}
6658 	return 0;
6659 }
6660 
6661 static __latent_entropy void net_rx_action(struct softirq_action *h)
6662 {
6663 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6664 	unsigned long time_limit = jiffies +
6665 		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6666 	int budget = READ_ONCE(netdev_budget);
6667 	LIST_HEAD(list);
6668 	LIST_HEAD(repoll);
6669 
6670 start:
6671 	sd->in_net_rx_action = true;
6672 	local_irq_disable();
6673 	list_splice_init(&sd->poll_list, &list);
6674 	local_irq_enable();
6675 
6676 	for (;;) {
6677 		struct napi_struct *n;
6678 
6679 		skb_defer_free_flush(sd);
6680 
6681 		if (list_empty(&list)) {
6682 			if (list_empty(&repoll)) {
6683 				sd->in_net_rx_action = false;
6684 				barrier();
6685 				/* We need to check if ____napi_schedule()
6686 				 * had refilled poll_list while
6687 				 * sd->in_net_rx_action was true.
6688 				 */
6689 				if (!list_empty(&sd->poll_list))
6690 					goto start;
6691 				if (!sd_has_rps_ipi_waiting(sd))
6692 					goto end;
6693 			}
6694 			break;
6695 		}
6696 
6697 		n = list_first_entry(&list, struct napi_struct, poll_list);
6698 		budget -= napi_poll(n, &repoll);
6699 
6700 		/* If softirq window is exhausted then punt.
6701 		 * Allow this to run for 2 jiffies since which will allow
6702 		 * an average latency of 1.5/HZ.
6703 		 */
6704 		if (unlikely(budget <= 0 ||
6705 			     time_after_eq(jiffies, time_limit))) {
6706 			sd->time_squeeze++;
6707 			break;
6708 		}
6709 	}
6710 
6711 	local_irq_disable();
6712 
6713 	list_splice_tail_init(&sd->poll_list, &list);
6714 	list_splice_tail(&repoll, &list);
6715 	list_splice(&list, &sd->poll_list);
6716 	if (!list_empty(&sd->poll_list))
6717 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6718 	else
6719 		sd->in_net_rx_action = false;
6720 
6721 	net_rps_action_and_irq_enable(sd);
6722 end:;
6723 }
6724 
6725 struct netdev_adjacent {
6726 	struct net_device *dev;
6727 	netdevice_tracker dev_tracker;
6728 
6729 	/* upper master flag, there can only be one master device per list */
6730 	bool master;
6731 
6732 	/* lookup ignore flag */
6733 	bool ignore;
6734 
6735 	/* counter for the number of times this device was added to us */
6736 	u16 ref_nr;
6737 
6738 	/* private field for the users */
6739 	void *private;
6740 
6741 	struct list_head list;
6742 	struct rcu_head rcu;
6743 };
6744 
6745 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6746 						 struct list_head *adj_list)
6747 {
6748 	struct netdev_adjacent *adj;
6749 
6750 	list_for_each_entry(adj, adj_list, list) {
6751 		if (adj->dev == adj_dev)
6752 			return adj;
6753 	}
6754 	return NULL;
6755 }
6756 
6757 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6758 				    struct netdev_nested_priv *priv)
6759 {
6760 	struct net_device *dev = (struct net_device *)priv->data;
6761 
6762 	return upper_dev == dev;
6763 }
6764 
6765 /**
6766  * netdev_has_upper_dev - Check if device is linked to an upper device
6767  * @dev: device
6768  * @upper_dev: upper device to check
6769  *
6770  * Find out if a device is linked to specified upper device and return true
6771  * in case it is. Note that this checks only immediate upper device,
6772  * not through a complete stack of devices. The caller must hold the RTNL lock.
6773  */
6774 bool netdev_has_upper_dev(struct net_device *dev,
6775 			  struct net_device *upper_dev)
6776 {
6777 	struct netdev_nested_priv priv = {
6778 		.data = (void *)upper_dev,
6779 	};
6780 
6781 	ASSERT_RTNL();
6782 
6783 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6784 					     &priv);
6785 }
6786 EXPORT_SYMBOL(netdev_has_upper_dev);
6787 
6788 /**
6789  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6790  * @dev: device
6791  * @upper_dev: upper device to check
6792  *
6793  * Find out if a device is linked to specified upper device and return true
6794  * in case it is. Note that this checks the entire upper device chain.
6795  * The caller must hold rcu lock.
6796  */
6797 
6798 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6799 				  struct net_device *upper_dev)
6800 {
6801 	struct netdev_nested_priv priv = {
6802 		.data = (void *)upper_dev,
6803 	};
6804 
6805 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6806 					       &priv);
6807 }
6808 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6809 
6810 /**
6811  * netdev_has_any_upper_dev - Check if device is linked to some device
6812  * @dev: device
6813  *
6814  * Find out if a device is linked to an upper device and return true in case
6815  * it is. The caller must hold the RTNL lock.
6816  */
6817 bool netdev_has_any_upper_dev(struct net_device *dev)
6818 {
6819 	ASSERT_RTNL();
6820 
6821 	return !list_empty(&dev->adj_list.upper);
6822 }
6823 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6824 
6825 /**
6826  * netdev_master_upper_dev_get - Get master upper device
6827  * @dev: device
6828  *
6829  * Find a master upper device and return pointer to it or NULL in case
6830  * it's not there. The caller must hold the RTNL lock.
6831  */
6832 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6833 {
6834 	struct netdev_adjacent *upper;
6835 
6836 	ASSERT_RTNL();
6837 
6838 	if (list_empty(&dev->adj_list.upper))
6839 		return NULL;
6840 
6841 	upper = list_first_entry(&dev->adj_list.upper,
6842 				 struct netdev_adjacent, list);
6843 	if (likely(upper->master))
6844 		return upper->dev;
6845 	return NULL;
6846 }
6847 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6848 
6849 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6850 {
6851 	struct netdev_adjacent *upper;
6852 
6853 	ASSERT_RTNL();
6854 
6855 	if (list_empty(&dev->adj_list.upper))
6856 		return NULL;
6857 
6858 	upper = list_first_entry(&dev->adj_list.upper,
6859 				 struct netdev_adjacent, list);
6860 	if (likely(upper->master) && !upper->ignore)
6861 		return upper->dev;
6862 	return NULL;
6863 }
6864 
6865 /**
6866  * netdev_has_any_lower_dev - Check if device is linked to some device
6867  * @dev: device
6868  *
6869  * Find out if a device is linked to a lower device and return true in case
6870  * it is. The caller must hold the RTNL lock.
6871  */
6872 static bool netdev_has_any_lower_dev(struct net_device *dev)
6873 {
6874 	ASSERT_RTNL();
6875 
6876 	return !list_empty(&dev->adj_list.lower);
6877 }
6878 
6879 void *netdev_adjacent_get_private(struct list_head *adj_list)
6880 {
6881 	struct netdev_adjacent *adj;
6882 
6883 	adj = list_entry(adj_list, struct netdev_adjacent, list);
6884 
6885 	return adj->private;
6886 }
6887 EXPORT_SYMBOL(netdev_adjacent_get_private);
6888 
6889 /**
6890  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6891  * @dev: device
6892  * @iter: list_head ** of the current position
6893  *
6894  * Gets the next device from the dev's upper list, starting from iter
6895  * position. The caller must hold RCU read lock.
6896  */
6897 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6898 						 struct list_head **iter)
6899 {
6900 	struct netdev_adjacent *upper;
6901 
6902 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6903 
6904 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6905 
6906 	if (&upper->list == &dev->adj_list.upper)
6907 		return NULL;
6908 
6909 	*iter = &upper->list;
6910 
6911 	return upper->dev;
6912 }
6913 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6914 
6915 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6916 						  struct list_head **iter,
6917 						  bool *ignore)
6918 {
6919 	struct netdev_adjacent *upper;
6920 
6921 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6922 
6923 	if (&upper->list == &dev->adj_list.upper)
6924 		return NULL;
6925 
6926 	*iter = &upper->list;
6927 	*ignore = upper->ignore;
6928 
6929 	return upper->dev;
6930 }
6931 
6932 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6933 						    struct list_head **iter)
6934 {
6935 	struct netdev_adjacent *upper;
6936 
6937 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6938 
6939 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6940 
6941 	if (&upper->list == &dev->adj_list.upper)
6942 		return NULL;
6943 
6944 	*iter = &upper->list;
6945 
6946 	return upper->dev;
6947 }
6948 
6949 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6950 				       int (*fn)(struct net_device *dev,
6951 					 struct netdev_nested_priv *priv),
6952 				       struct netdev_nested_priv *priv)
6953 {
6954 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6955 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6956 	int ret, cur = 0;
6957 	bool ignore;
6958 
6959 	now = dev;
6960 	iter = &dev->adj_list.upper;
6961 
6962 	while (1) {
6963 		if (now != dev) {
6964 			ret = fn(now, priv);
6965 			if (ret)
6966 				return ret;
6967 		}
6968 
6969 		next = NULL;
6970 		while (1) {
6971 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
6972 			if (!udev)
6973 				break;
6974 			if (ignore)
6975 				continue;
6976 
6977 			next = udev;
6978 			niter = &udev->adj_list.upper;
6979 			dev_stack[cur] = now;
6980 			iter_stack[cur++] = iter;
6981 			break;
6982 		}
6983 
6984 		if (!next) {
6985 			if (!cur)
6986 				return 0;
6987 			next = dev_stack[--cur];
6988 			niter = iter_stack[cur];
6989 		}
6990 
6991 		now = next;
6992 		iter = niter;
6993 	}
6994 
6995 	return 0;
6996 }
6997 
6998 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6999 				  int (*fn)(struct net_device *dev,
7000 					    struct netdev_nested_priv *priv),
7001 				  struct netdev_nested_priv *priv)
7002 {
7003 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7004 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7005 	int ret, cur = 0;
7006 
7007 	now = dev;
7008 	iter = &dev->adj_list.upper;
7009 
7010 	while (1) {
7011 		if (now != dev) {
7012 			ret = fn(now, priv);
7013 			if (ret)
7014 				return ret;
7015 		}
7016 
7017 		next = NULL;
7018 		while (1) {
7019 			udev = netdev_next_upper_dev_rcu(now, &iter);
7020 			if (!udev)
7021 				break;
7022 
7023 			next = udev;
7024 			niter = &udev->adj_list.upper;
7025 			dev_stack[cur] = now;
7026 			iter_stack[cur++] = iter;
7027 			break;
7028 		}
7029 
7030 		if (!next) {
7031 			if (!cur)
7032 				return 0;
7033 			next = dev_stack[--cur];
7034 			niter = iter_stack[cur];
7035 		}
7036 
7037 		now = next;
7038 		iter = niter;
7039 	}
7040 
7041 	return 0;
7042 }
7043 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7044 
7045 static bool __netdev_has_upper_dev(struct net_device *dev,
7046 				   struct net_device *upper_dev)
7047 {
7048 	struct netdev_nested_priv priv = {
7049 		.flags = 0,
7050 		.data = (void *)upper_dev,
7051 	};
7052 
7053 	ASSERT_RTNL();
7054 
7055 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7056 					   &priv);
7057 }
7058 
7059 /**
7060  * netdev_lower_get_next_private - Get the next ->private from the
7061  *				   lower neighbour list
7062  * @dev: device
7063  * @iter: list_head ** of the current position
7064  *
7065  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7066  * list, starting from iter position. The caller must hold either hold the
7067  * RTNL lock or its own locking that guarantees that the neighbour lower
7068  * list will remain unchanged.
7069  */
7070 void *netdev_lower_get_next_private(struct net_device *dev,
7071 				    struct list_head **iter)
7072 {
7073 	struct netdev_adjacent *lower;
7074 
7075 	lower = list_entry(*iter, struct netdev_adjacent, list);
7076 
7077 	if (&lower->list == &dev->adj_list.lower)
7078 		return NULL;
7079 
7080 	*iter = lower->list.next;
7081 
7082 	return lower->private;
7083 }
7084 EXPORT_SYMBOL(netdev_lower_get_next_private);
7085 
7086 /**
7087  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7088  *				       lower neighbour list, RCU
7089  *				       variant
7090  * @dev: device
7091  * @iter: list_head ** of the current position
7092  *
7093  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7094  * list, starting from iter position. The caller must hold RCU read lock.
7095  */
7096 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7097 					struct list_head **iter)
7098 {
7099 	struct netdev_adjacent *lower;
7100 
7101 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7102 
7103 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7104 
7105 	if (&lower->list == &dev->adj_list.lower)
7106 		return NULL;
7107 
7108 	*iter = &lower->list;
7109 
7110 	return lower->private;
7111 }
7112 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7113 
7114 /**
7115  * netdev_lower_get_next - Get the next device from the lower neighbour
7116  *                         list
7117  * @dev: device
7118  * @iter: list_head ** of the current position
7119  *
7120  * Gets the next netdev_adjacent from the dev's lower neighbour
7121  * list, starting from iter position. The caller must hold RTNL lock or
7122  * its own locking that guarantees that the neighbour lower
7123  * list will remain unchanged.
7124  */
7125 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7126 {
7127 	struct netdev_adjacent *lower;
7128 
7129 	lower = list_entry(*iter, struct netdev_adjacent, list);
7130 
7131 	if (&lower->list == &dev->adj_list.lower)
7132 		return NULL;
7133 
7134 	*iter = lower->list.next;
7135 
7136 	return lower->dev;
7137 }
7138 EXPORT_SYMBOL(netdev_lower_get_next);
7139 
7140 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7141 						struct list_head **iter)
7142 {
7143 	struct netdev_adjacent *lower;
7144 
7145 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7146 
7147 	if (&lower->list == &dev->adj_list.lower)
7148 		return NULL;
7149 
7150 	*iter = &lower->list;
7151 
7152 	return lower->dev;
7153 }
7154 
7155 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7156 						  struct list_head **iter,
7157 						  bool *ignore)
7158 {
7159 	struct netdev_adjacent *lower;
7160 
7161 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7162 
7163 	if (&lower->list == &dev->adj_list.lower)
7164 		return NULL;
7165 
7166 	*iter = &lower->list;
7167 	*ignore = lower->ignore;
7168 
7169 	return lower->dev;
7170 }
7171 
7172 int netdev_walk_all_lower_dev(struct net_device *dev,
7173 			      int (*fn)(struct net_device *dev,
7174 					struct netdev_nested_priv *priv),
7175 			      struct netdev_nested_priv *priv)
7176 {
7177 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7178 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7179 	int ret, cur = 0;
7180 
7181 	now = dev;
7182 	iter = &dev->adj_list.lower;
7183 
7184 	while (1) {
7185 		if (now != dev) {
7186 			ret = fn(now, priv);
7187 			if (ret)
7188 				return ret;
7189 		}
7190 
7191 		next = NULL;
7192 		while (1) {
7193 			ldev = netdev_next_lower_dev(now, &iter);
7194 			if (!ldev)
7195 				break;
7196 
7197 			next = ldev;
7198 			niter = &ldev->adj_list.lower;
7199 			dev_stack[cur] = now;
7200 			iter_stack[cur++] = iter;
7201 			break;
7202 		}
7203 
7204 		if (!next) {
7205 			if (!cur)
7206 				return 0;
7207 			next = dev_stack[--cur];
7208 			niter = iter_stack[cur];
7209 		}
7210 
7211 		now = next;
7212 		iter = niter;
7213 	}
7214 
7215 	return 0;
7216 }
7217 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7218 
7219 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7220 				       int (*fn)(struct net_device *dev,
7221 					 struct netdev_nested_priv *priv),
7222 				       struct netdev_nested_priv *priv)
7223 {
7224 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7225 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7226 	int ret, cur = 0;
7227 	bool ignore;
7228 
7229 	now = dev;
7230 	iter = &dev->adj_list.lower;
7231 
7232 	while (1) {
7233 		if (now != dev) {
7234 			ret = fn(now, priv);
7235 			if (ret)
7236 				return ret;
7237 		}
7238 
7239 		next = NULL;
7240 		while (1) {
7241 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7242 			if (!ldev)
7243 				break;
7244 			if (ignore)
7245 				continue;
7246 
7247 			next = ldev;
7248 			niter = &ldev->adj_list.lower;
7249 			dev_stack[cur] = now;
7250 			iter_stack[cur++] = iter;
7251 			break;
7252 		}
7253 
7254 		if (!next) {
7255 			if (!cur)
7256 				return 0;
7257 			next = dev_stack[--cur];
7258 			niter = iter_stack[cur];
7259 		}
7260 
7261 		now = next;
7262 		iter = niter;
7263 	}
7264 
7265 	return 0;
7266 }
7267 
7268 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7269 					     struct list_head **iter)
7270 {
7271 	struct netdev_adjacent *lower;
7272 
7273 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7274 	if (&lower->list == &dev->adj_list.lower)
7275 		return NULL;
7276 
7277 	*iter = &lower->list;
7278 
7279 	return lower->dev;
7280 }
7281 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7282 
7283 static u8 __netdev_upper_depth(struct net_device *dev)
7284 {
7285 	struct net_device *udev;
7286 	struct list_head *iter;
7287 	u8 max_depth = 0;
7288 	bool ignore;
7289 
7290 	for (iter = &dev->adj_list.upper,
7291 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7292 	     udev;
7293 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7294 		if (ignore)
7295 			continue;
7296 		if (max_depth < udev->upper_level)
7297 			max_depth = udev->upper_level;
7298 	}
7299 
7300 	return max_depth;
7301 }
7302 
7303 static u8 __netdev_lower_depth(struct net_device *dev)
7304 {
7305 	struct net_device *ldev;
7306 	struct list_head *iter;
7307 	u8 max_depth = 0;
7308 	bool ignore;
7309 
7310 	for (iter = &dev->adj_list.lower,
7311 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7312 	     ldev;
7313 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7314 		if (ignore)
7315 			continue;
7316 		if (max_depth < ldev->lower_level)
7317 			max_depth = ldev->lower_level;
7318 	}
7319 
7320 	return max_depth;
7321 }
7322 
7323 static int __netdev_update_upper_level(struct net_device *dev,
7324 				       struct netdev_nested_priv *__unused)
7325 {
7326 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7327 	return 0;
7328 }
7329 
7330 #ifdef CONFIG_LOCKDEP
7331 static LIST_HEAD(net_unlink_list);
7332 
7333 static void net_unlink_todo(struct net_device *dev)
7334 {
7335 	if (list_empty(&dev->unlink_list))
7336 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7337 }
7338 #endif
7339 
7340 static int __netdev_update_lower_level(struct net_device *dev,
7341 				       struct netdev_nested_priv *priv)
7342 {
7343 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7344 
7345 #ifdef CONFIG_LOCKDEP
7346 	if (!priv)
7347 		return 0;
7348 
7349 	if (priv->flags & NESTED_SYNC_IMM)
7350 		dev->nested_level = dev->lower_level - 1;
7351 	if (priv->flags & NESTED_SYNC_TODO)
7352 		net_unlink_todo(dev);
7353 #endif
7354 	return 0;
7355 }
7356 
7357 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7358 				  int (*fn)(struct net_device *dev,
7359 					    struct netdev_nested_priv *priv),
7360 				  struct netdev_nested_priv *priv)
7361 {
7362 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7363 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7364 	int ret, cur = 0;
7365 
7366 	now = dev;
7367 	iter = &dev->adj_list.lower;
7368 
7369 	while (1) {
7370 		if (now != dev) {
7371 			ret = fn(now, priv);
7372 			if (ret)
7373 				return ret;
7374 		}
7375 
7376 		next = NULL;
7377 		while (1) {
7378 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7379 			if (!ldev)
7380 				break;
7381 
7382 			next = ldev;
7383 			niter = &ldev->adj_list.lower;
7384 			dev_stack[cur] = now;
7385 			iter_stack[cur++] = iter;
7386 			break;
7387 		}
7388 
7389 		if (!next) {
7390 			if (!cur)
7391 				return 0;
7392 			next = dev_stack[--cur];
7393 			niter = iter_stack[cur];
7394 		}
7395 
7396 		now = next;
7397 		iter = niter;
7398 	}
7399 
7400 	return 0;
7401 }
7402 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7403 
7404 /**
7405  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7406  *				       lower neighbour list, RCU
7407  *				       variant
7408  * @dev: device
7409  *
7410  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7411  * list. The caller must hold RCU read lock.
7412  */
7413 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7414 {
7415 	struct netdev_adjacent *lower;
7416 
7417 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7418 			struct netdev_adjacent, list);
7419 	if (lower)
7420 		return lower->private;
7421 	return NULL;
7422 }
7423 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7424 
7425 /**
7426  * netdev_master_upper_dev_get_rcu - Get master upper device
7427  * @dev: device
7428  *
7429  * Find a master upper device and return pointer to it or NULL in case
7430  * it's not there. The caller must hold the RCU read lock.
7431  */
7432 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7433 {
7434 	struct netdev_adjacent *upper;
7435 
7436 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7437 				       struct netdev_adjacent, list);
7438 	if (upper && likely(upper->master))
7439 		return upper->dev;
7440 	return NULL;
7441 }
7442 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7443 
7444 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7445 			      struct net_device *adj_dev,
7446 			      struct list_head *dev_list)
7447 {
7448 	char linkname[IFNAMSIZ+7];
7449 
7450 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7451 		"upper_%s" : "lower_%s", adj_dev->name);
7452 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7453 				 linkname);
7454 }
7455 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7456 			       char *name,
7457 			       struct list_head *dev_list)
7458 {
7459 	char linkname[IFNAMSIZ+7];
7460 
7461 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7462 		"upper_%s" : "lower_%s", name);
7463 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7464 }
7465 
7466 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7467 						 struct net_device *adj_dev,
7468 						 struct list_head *dev_list)
7469 {
7470 	return (dev_list == &dev->adj_list.upper ||
7471 		dev_list == &dev->adj_list.lower) &&
7472 		net_eq(dev_net(dev), dev_net(adj_dev));
7473 }
7474 
7475 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7476 					struct net_device *adj_dev,
7477 					struct list_head *dev_list,
7478 					void *private, bool master)
7479 {
7480 	struct netdev_adjacent *adj;
7481 	int ret;
7482 
7483 	adj = __netdev_find_adj(adj_dev, dev_list);
7484 
7485 	if (adj) {
7486 		adj->ref_nr += 1;
7487 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7488 			 dev->name, adj_dev->name, adj->ref_nr);
7489 
7490 		return 0;
7491 	}
7492 
7493 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7494 	if (!adj)
7495 		return -ENOMEM;
7496 
7497 	adj->dev = adj_dev;
7498 	adj->master = master;
7499 	adj->ref_nr = 1;
7500 	adj->private = private;
7501 	adj->ignore = false;
7502 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7503 
7504 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7505 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7506 
7507 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7508 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7509 		if (ret)
7510 			goto free_adj;
7511 	}
7512 
7513 	/* Ensure that master link is always the first item in list. */
7514 	if (master) {
7515 		ret = sysfs_create_link(&(dev->dev.kobj),
7516 					&(adj_dev->dev.kobj), "master");
7517 		if (ret)
7518 			goto remove_symlinks;
7519 
7520 		list_add_rcu(&adj->list, dev_list);
7521 	} else {
7522 		list_add_tail_rcu(&adj->list, dev_list);
7523 	}
7524 
7525 	return 0;
7526 
7527 remove_symlinks:
7528 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7529 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7530 free_adj:
7531 	netdev_put(adj_dev, &adj->dev_tracker);
7532 	kfree(adj);
7533 
7534 	return ret;
7535 }
7536 
7537 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7538 					 struct net_device *adj_dev,
7539 					 u16 ref_nr,
7540 					 struct list_head *dev_list)
7541 {
7542 	struct netdev_adjacent *adj;
7543 
7544 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7545 		 dev->name, adj_dev->name, ref_nr);
7546 
7547 	adj = __netdev_find_adj(adj_dev, dev_list);
7548 
7549 	if (!adj) {
7550 		pr_err("Adjacency does not exist for device %s from %s\n",
7551 		       dev->name, adj_dev->name);
7552 		WARN_ON(1);
7553 		return;
7554 	}
7555 
7556 	if (adj->ref_nr > ref_nr) {
7557 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7558 			 dev->name, adj_dev->name, ref_nr,
7559 			 adj->ref_nr - ref_nr);
7560 		adj->ref_nr -= ref_nr;
7561 		return;
7562 	}
7563 
7564 	if (adj->master)
7565 		sysfs_remove_link(&(dev->dev.kobj), "master");
7566 
7567 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7568 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7569 
7570 	list_del_rcu(&adj->list);
7571 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7572 		 adj_dev->name, dev->name, adj_dev->name);
7573 	netdev_put(adj_dev, &adj->dev_tracker);
7574 	kfree_rcu(adj, rcu);
7575 }
7576 
7577 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7578 					    struct net_device *upper_dev,
7579 					    struct list_head *up_list,
7580 					    struct list_head *down_list,
7581 					    void *private, bool master)
7582 {
7583 	int ret;
7584 
7585 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7586 					   private, master);
7587 	if (ret)
7588 		return ret;
7589 
7590 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7591 					   private, false);
7592 	if (ret) {
7593 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7594 		return ret;
7595 	}
7596 
7597 	return 0;
7598 }
7599 
7600 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7601 					       struct net_device *upper_dev,
7602 					       u16 ref_nr,
7603 					       struct list_head *up_list,
7604 					       struct list_head *down_list)
7605 {
7606 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7607 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7608 }
7609 
7610 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7611 						struct net_device *upper_dev,
7612 						void *private, bool master)
7613 {
7614 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7615 						&dev->adj_list.upper,
7616 						&upper_dev->adj_list.lower,
7617 						private, master);
7618 }
7619 
7620 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7621 						   struct net_device *upper_dev)
7622 {
7623 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7624 					   &dev->adj_list.upper,
7625 					   &upper_dev->adj_list.lower);
7626 }
7627 
7628 static int __netdev_upper_dev_link(struct net_device *dev,
7629 				   struct net_device *upper_dev, bool master,
7630 				   void *upper_priv, void *upper_info,
7631 				   struct netdev_nested_priv *priv,
7632 				   struct netlink_ext_ack *extack)
7633 {
7634 	struct netdev_notifier_changeupper_info changeupper_info = {
7635 		.info = {
7636 			.dev = dev,
7637 			.extack = extack,
7638 		},
7639 		.upper_dev = upper_dev,
7640 		.master = master,
7641 		.linking = true,
7642 		.upper_info = upper_info,
7643 	};
7644 	struct net_device *master_dev;
7645 	int ret = 0;
7646 
7647 	ASSERT_RTNL();
7648 
7649 	if (dev == upper_dev)
7650 		return -EBUSY;
7651 
7652 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7653 	if (__netdev_has_upper_dev(upper_dev, dev))
7654 		return -EBUSY;
7655 
7656 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7657 		return -EMLINK;
7658 
7659 	if (!master) {
7660 		if (__netdev_has_upper_dev(dev, upper_dev))
7661 			return -EEXIST;
7662 	} else {
7663 		master_dev = __netdev_master_upper_dev_get(dev);
7664 		if (master_dev)
7665 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7666 	}
7667 
7668 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7669 					    &changeupper_info.info);
7670 	ret = notifier_to_errno(ret);
7671 	if (ret)
7672 		return ret;
7673 
7674 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7675 						   master);
7676 	if (ret)
7677 		return ret;
7678 
7679 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7680 					    &changeupper_info.info);
7681 	ret = notifier_to_errno(ret);
7682 	if (ret)
7683 		goto rollback;
7684 
7685 	__netdev_update_upper_level(dev, NULL);
7686 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7687 
7688 	__netdev_update_lower_level(upper_dev, priv);
7689 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7690 				    priv);
7691 
7692 	return 0;
7693 
7694 rollback:
7695 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7696 
7697 	return ret;
7698 }
7699 
7700 /**
7701  * netdev_upper_dev_link - Add a link to the upper device
7702  * @dev: device
7703  * @upper_dev: new upper device
7704  * @extack: netlink extended ack
7705  *
7706  * Adds a link to device which is upper to this one. The caller must hold
7707  * the RTNL lock. On a failure a negative errno code is returned.
7708  * On success the reference counts are adjusted and the function
7709  * returns zero.
7710  */
7711 int netdev_upper_dev_link(struct net_device *dev,
7712 			  struct net_device *upper_dev,
7713 			  struct netlink_ext_ack *extack)
7714 {
7715 	struct netdev_nested_priv priv = {
7716 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7717 		.data = NULL,
7718 	};
7719 
7720 	return __netdev_upper_dev_link(dev, upper_dev, false,
7721 				       NULL, NULL, &priv, extack);
7722 }
7723 EXPORT_SYMBOL(netdev_upper_dev_link);
7724 
7725 /**
7726  * netdev_master_upper_dev_link - Add a master link to the upper device
7727  * @dev: device
7728  * @upper_dev: new upper device
7729  * @upper_priv: upper device private
7730  * @upper_info: upper info to be passed down via notifier
7731  * @extack: netlink extended ack
7732  *
7733  * Adds a link to device which is upper to this one. In this case, only
7734  * one master upper device can be linked, although other non-master devices
7735  * might be linked as well. The caller must hold the RTNL lock.
7736  * On a failure a negative errno code is returned. On success the reference
7737  * counts are adjusted and the function returns zero.
7738  */
7739 int netdev_master_upper_dev_link(struct net_device *dev,
7740 				 struct net_device *upper_dev,
7741 				 void *upper_priv, void *upper_info,
7742 				 struct netlink_ext_ack *extack)
7743 {
7744 	struct netdev_nested_priv priv = {
7745 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7746 		.data = NULL,
7747 	};
7748 
7749 	return __netdev_upper_dev_link(dev, upper_dev, true,
7750 				       upper_priv, upper_info, &priv, extack);
7751 }
7752 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7753 
7754 static void __netdev_upper_dev_unlink(struct net_device *dev,
7755 				      struct net_device *upper_dev,
7756 				      struct netdev_nested_priv *priv)
7757 {
7758 	struct netdev_notifier_changeupper_info changeupper_info = {
7759 		.info = {
7760 			.dev = dev,
7761 		},
7762 		.upper_dev = upper_dev,
7763 		.linking = false,
7764 	};
7765 
7766 	ASSERT_RTNL();
7767 
7768 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7769 
7770 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7771 				      &changeupper_info.info);
7772 
7773 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7774 
7775 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7776 				      &changeupper_info.info);
7777 
7778 	__netdev_update_upper_level(dev, NULL);
7779 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7780 
7781 	__netdev_update_lower_level(upper_dev, priv);
7782 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7783 				    priv);
7784 }
7785 
7786 /**
7787  * netdev_upper_dev_unlink - Removes a link to upper device
7788  * @dev: device
7789  * @upper_dev: new upper device
7790  *
7791  * Removes a link to device which is upper to this one. The caller must hold
7792  * the RTNL lock.
7793  */
7794 void netdev_upper_dev_unlink(struct net_device *dev,
7795 			     struct net_device *upper_dev)
7796 {
7797 	struct netdev_nested_priv priv = {
7798 		.flags = NESTED_SYNC_TODO,
7799 		.data = NULL,
7800 	};
7801 
7802 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
7803 }
7804 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7805 
7806 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7807 				      struct net_device *lower_dev,
7808 				      bool val)
7809 {
7810 	struct netdev_adjacent *adj;
7811 
7812 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7813 	if (adj)
7814 		adj->ignore = val;
7815 
7816 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7817 	if (adj)
7818 		adj->ignore = val;
7819 }
7820 
7821 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7822 					struct net_device *lower_dev)
7823 {
7824 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7825 }
7826 
7827 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7828 				       struct net_device *lower_dev)
7829 {
7830 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7831 }
7832 
7833 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7834 				   struct net_device *new_dev,
7835 				   struct net_device *dev,
7836 				   struct netlink_ext_ack *extack)
7837 {
7838 	struct netdev_nested_priv priv = {
7839 		.flags = 0,
7840 		.data = NULL,
7841 	};
7842 	int err;
7843 
7844 	if (!new_dev)
7845 		return 0;
7846 
7847 	if (old_dev && new_dev != old_dev)
7848 		netdev_adjacent_dev_disable(dev, old_dev);
7849 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7850 				      extack);
7851 	if (err) {
7852 		if (old_dev && new_dev != old_dev)
7853 			netdev_adjacent_dev_enable(dev, old_dev);
7854 		return err;
7855 	}
7856 
7857 	return 0;
7858 }
7859 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7860 
7861 void netdev_adjacent_change_commit(struct net_device *old_dev,
7862 				   struct net_device *new_dev,
7863 				   struct net_device *dev)
7864 {
7865 	struct netdev_nested_priv priv = {
7866 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7867 		.data = NULL,
7868 	};
7869 
7870 	if (!new_dev || !old_dev)
7871 		return;
7872 
7873 	if (new_dev == old_dev)
7874 		return;
7875 
7876 	netdev_adjacent_dev_enable(dev, old_dev);
7877 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
7878 }
7879 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7880 
7881 void netdev_adjacent_change_abort(struct net_device *old_dev,
7882 				  struct net_device *new_dev,
7883 				  struct net_device *dev)
7884 {
7885 	struct netdev_nested_priv priv = {
7886 		.flags = 0,
7887 		.data = NULL,
7888 	};
7889 
7890 	if (!new_dev)
7891 		return;
7892 
7893 	if (old_dev && new_dev != old_dev)
7894 		netdev_adjacent_dev_enable(dev, old_dev);
7895 
7896 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
7897 }
7898 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7899 
7900 /**
7901  * netdev_bonding_info_change - Dispatch event about slave change
7902  * @dev: device
7903  * @bonding_info: info to dispatch
7904  *
7905  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7906  * The caller must hold the RTNL lock.
7907  */
7908 void netdev_bonding_info_change(struct net_device *dev,
7909 				struct netdev_bonding_info *bonding_info)
7910 {
7911 	struct netdev_notifier_bonding_info info = {
7912 		.info.dev = dev,
7913 	};
7914 
7915 	memcpy(&info.bonding_info, bonding_info,
7916 	       sizeof(struct netdev_bonding_info));
7917 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7918 				      &info.info);
7919 }
7920 EXPORT_SYMBOL(netdev_bonding_info_change);
7921 
7922 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7923 					   struct netlink_ext_ack *extack)
7924 {
7925 	struct netdev_notifier_offload_xstats_info info = {
7926 		.info.dev = dev,
7927 		.info.extack = extack,
7928 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7929 	};
7930 	int err;
7931 	int rc;
7932 
7933 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7934 					 GFP_KERNEL);
7935 	if (!dev->offload_xstats_l3)
7936 		return -ENOMEM;
7937 
7938 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7939 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
7940 						  &info.info);
7941 	err = notifier_to_errno(rc);
7942 	if (err)
7943 		goto free_stats;
7944 
7945 	return 0;
7946 
7947 free_stats:
7948 	kfree(dev->offload_xstats_l3);
7949 	dev->offload_xstats_l3 = NULL;
7950 	return err;
7951 }
7952 
7953 int netdev_offload_xstats_enable(struct net_device *dev,
7954 				 enum netdev_offload_xstats_type type,
7955 				 struct netlink_ext_ack *extack)
7956 {
7957 	ASSERT_RTNL();
7958 
7959 	if (netdev_offload_xstats_enabled(dev, type))
7960 		return -EALREADY;
7961 
7962 	switch (type) {
7963 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7964 		return netdev_offload_xstats_enable_l3(dev, extack);
7965 	}
7966 
7967 	WARN_ON(1);
7968 	return -EINVAL;
7969 }
7970 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7971 
7972 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7973 {
7974 	struct netdev_notifier_offload_xstats_info info = {
7975 		.info.dev = dev,
7976 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7977 	};
7978 
7979 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
7980 				      &info.info);
7981 	kfree(dev->offload_xstats_l3);
7982 	dev->offload_xstats_l3 = NULL;
7983 }
7984 
7985 int netdev_offload_xstats_disable(struct net_device *dev,
7986 				  enum netdev_offload_xstats_type type)
7987 {
7988 	ASSERT_RTNL();
7989 
7990 	if (!netdev_offload_xstats_enabled(dev, type))
7991 		return -EALREADY;
7992 
7993 	switch (type) {
7994 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7995 		netdev_offload_xstats_disable_l3(dev);
7996 		return 0;
7997 	}
7998 
7999 	WARN_ON(1);
8000 	return -EINVAL;
8001 }
8002 EXPORT_SYMBOL(netdev_offload_xstats_disable);
8003 
8004 static void netdev_offload_xstats_disable_all(struct net_device *dev)
8005 {
8006 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
8007 }
8008 
8009 static struct rtnl_hw_stats64 *
8010 netdev_offload_xstats_get_ptr(const struct net_device *dev,
8011 			      enum netdev_offload_xstats_type type)
8012 {
8013 	switch (type) {
8014 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8015 		return dev->offload_xstats_l3;
8016 	}
8017 
8018 	WARN_ON(1);
8019 	return NULL;
8020 }
8021 
8022 bool netdev_offload_xstats_enabled(const struct net_device *dev,
8023 				   enum netdev_offload_xstats_type type)
8024 {
8025 	ASSERT_RTNL();
8026 
8027 	return netdev_offload_xstats_get_ptr(dev, type);
8028 }
8029 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8030 
8031 struct netdev_notifier_offload_xstats_ru {
8032 	bool used;
8033 };
8034 
8035 struct netdev_notifier_offload_xstats_rd {
8036 	struct rtnl_hw_stats64 stats;
8037 	bool used;
8038 };
8039 
8040 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8041 				  const struct rtnl_hw_stats64 *src)
8042 {
8043 	dest->rx_packets	  += src->rx_packets;
8044 	dest->tx_packets	  += src->tx_packets;
8045 	dest->rx_bytes		  += src->rx_bytes;
8046 	dest->tx_bytes		  += src->tx_bytes;
8047 	dest->rx_errors		  += src->rx_errors;
8048 	dest->tx_errors		  += src->tx_errors;
8049 	dest->rx_dropped	  += src->rx_dropped;
8050 	dest->tx_dropped	  += src->tx_dropped;
8051 	dest->multicast		  += src->multicast;
8052 }
8053 
8054 static int netdev_offload_xstats_get_used(struct net_device *dev,
8055 					  enum netdev_offload_xstats_type type,
8056 					  bool *p_used,
8057 					  struct netlink_ext_ack *extack)
8058 {
8059 	struct netdev_notifier_offload_xstats_ru report_used = {};
8060 	struct netdev_notifier_offload_xstats_info info = {
8061 		.info.dev = dev,
8062 		.info.extack = extack,
8063 		.type = type,
8064 		.report_used = &report_used,
8065 	};
8066 	int rc;
8067 
8068 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8069 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8070 					   &info.info);
8071 	*p_used = report_used.used;
8072 	return notifier_to_errno(rc);
8073 }
8074 
8075 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8076 					   enum netdev_offload_xstats_type type,
8077 					   struct rtnl_hw_stats64 *p_stats,
8078 					   bool *p_used,
8079 					   struct netlink_ext_ack *extack)
8080 {
8081 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8082 	struct netdev_notifier_offload_xstats_info info = {
8083 		.info.dev = dev,
8084 		.info.extack = extack,
8085 		.type = type,
8086 		.report_delta = &report_delta,
8087 	};
8088 	struct rtnl_hw_stats64 *stats;
8089 	int rc;
8090 
8091 	stats = netdev_offload_xstats_get_ptr(dev, type);
8092 	if (WARN_ON(!stats))
8093 		return -EINVAL;
8094 
8095 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8096 					   &info.info);
8097 
8098 	/* Cache whatever we got, even if there was an error, otherwise the
8099 	 * successful stats retrievals would get lost.
8100 	 */
8101 	netdev_hw_stats64_add(stats, &report_delta.stats);
8102 
8103 	if (p_stats)
8104 		*p_stats = *stats;
8105 	*p_used = report_delta.used;
8106 
8107 	return notifier_to_errno(rc);
8108 }
8109 
8110 int netdev_offload_xstats_get(struct net_device *dev,
8111 			      enum netdev_offload_xstats_type type,
8112 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8113 			      struct netlink_ext_ack *extack)
8114 {
8115 	ASSERT_RTNL();
8116 
8117 	if (p_stats)
8118 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8119 						       p_used, extack);
8120 	else
8121 		return netdev_offload_xstats_get_used(dev, type, p_used,
8122 						      extack);
8123 }
8124 EXPORT_SYMBOL(netdev_offload_xstats_get);
8125 
8126 void
8127 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8128 				   const struct rtnl_hw_stats64 *stats)
8129 {
8130 	report_delta->used = true;
8131 	netdev_hw_stats64_add(&report_delta->stats, stats);
8132 }
8133 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8134 
8135 void
8136 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8137 {
8138 	report_used->used = true;
8139 }
8140 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8141 
8142 void netdev_offload_xstats_push_delta(struct net_device *dev,
8143 				      enum netdev_offload_xstats_type type,
8144 				      const struct rtnl_hw_stats64 *p_stats)
8145 {
8146 	struct rtnl_hw_stats64 *stats;
8147 
8148 	ASSERT_RTNL();
8149 
8150 	stats = netdev_offload_xstats_get_ptr(dev, type);
8151 	if (WARN_ON(!stats))
8152 		return;
8153 
8154 	netdev_hw_stats64_add(stats, p_stats);
8155 }
8156 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8157 
8158 /**
8159  * netdev_get_xmit_slave - Get the xmit slave of master device
8160  * @dev: device
8161  * @skb: The packet
8162  * @all_slaves: assume all the slaves are active
8163  *
8164  * The reference counters are not incremented so the caller must be
8165  * careful with locks. The caller must hold RCU lock.
8166  * %NULL is returned if no slave is found.
8167  */
8168 
8169 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8170 					 struct sk_buff *skb,
8171 					 bool all_slaves)
8172 {
8173 	const struct net_device_ops *ops = dev->netdev_ops;
8174 
8175 	if (!ops->ndo_get_xmit_slave)
8176 		return NULL;
8177 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8178 }
8179 EXPORT_SYMBOL(netdev_get_xmit_slave);
8180 
8181 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8182 						  struct sock *sk)
8183 {
8184 	const struct net_device_ops *ops = dev->netdev_ops;
8185 
8186 	if (!ops->ndo_sk_get_lower_dev)
8187 		return NULL;
8188 	return ops->ndo_sk_get_lower_dev(dev, sk);
8189 }
8190 
8191 /**
8192  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8193  * @dev: device
8194  * @sk: the socket
8195  *
8196  * %NULL is returned if no lower device is found.
8197  */
8198 
8199 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8200 					    struct sock *sk)
8201 {
8202 	struct net_device *lower;
8203 
8204 	lower = netdev_sk_get_lower_dev(dev, sk);
8205 	while (lower) {
8206 		dev = lower;
8207 		lower = netdev_sk_get_lower_dev(dev, sk);
8208 	}
8209 
8210 	return dev;
8211 }
8212 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8213 
8214 static void netdev_adjacent_add_links(struct net_device *dev)
8215 {
8216 	struct netdev_adjacent *iter;
8217 
8218 	struct net *net = dev_net(dev);
8219 
8220 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8221 		if (!net_eq(net, dev_net(iter->dev)))
8222 			continue;
8223 		netdev_adjacent_sysfs_add(iter->dev, dev,
8224 					  &iter->dev->adj_list.lower);
8225 		netdev_adjacent_sysfs_add(dev, iter->dev,
8226 					  &dev->adj_list.upper);
8227 	}
8228 
8229 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8230 		if (!net_eq(net, dev_net(iter->dev)))
8231 			continue;
8232 		netdev_adjacent_sysfs_add(iter->dev, dev,
8233 					  &iter->dev->adj_list.upper);
8234 		netdev_adjacent_sysfs_add(dev, iter->dev,
8235 					  &dev->adj_list.lower);
8236 	}
8237 }
8238 
8239 static void netdev_adjacent_del_links(struct net_device *dev)
8240 {
8241 	struct netdev_adjacent *iter;
8242 
8243 	struct net *net = dev_net(dev);
8244 
8245 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8246 		if (!net_eq(net, dev_net(iter->dev)))
8247 			continue;
8248 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8249 					  &iter->dev->adj_list.lower);
8250 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8251 					  &dev->adj_list.upper);
8252 	}
8253 
8254 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8255 		if (!net_eq(net, dev_net(iter->dev)))
8256 			continue;
8257 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8258 					  &iter->dev->adj_list.upper);
8259 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8260 					  &dev->adj_list.lower);
8261 	}
8262 }
8263 
8264 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8265 {
8266 	struct netdev_adjacent *iter;
8267 
8268 	struct net *net = dev_net(dev);
8269 
8270 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8271 		if (!net_eq(net, dev_net(iter->dev)))
8272 			continue;
8273 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8274 					  &iter->dev->adj_list.lower);
8275 		netdev_adjacent_sysfs_add(iter->dev, dev,
8276 					  &iter->dev->adj_list.lower);
8277 	}
8278 
8279 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8280 		if (!net_eq(net, dev_net(iter->dev)))
8281 			continue;
8282 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8283 					  &iter->dev->adj_list.upper);
8284 		netdev_adjacent_sysfs_add(iter->dev, dev,
8285 					  &iter->dev->adj_list.upper);
8286 	}
8287 }
8288 
8289 void *netdev_lower_dev_get_private(struct net_device *dev,
8290 				   struct net_device *lower_dev)
8291 {
8292 	struct netdev_adjacent *lower;
8293 
8294 	if (!lower_dev)
8295 		return NULL;
8296 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8297 	if (!lower)
8298 		return NULL;
8299 
8300 	return lower->private;
8301 }
8302 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8303 
8304 
8305 /**
8306  * netdev_lower_state_changed - Dispatch event about lower device state change
8307  * @lower_dev: device
8308  * @lower_state_info: state to dispatch
8309  *
8310  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8311  * The caller must hold the RTNL lock.
8312  */
8313 void netdev_lower_state_changed(struct net_device *lower_dev,
8314 				void *lower_state_info)
8315 {
8316 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8317 		.info.dev = lower_dev,
8318 	};
8319 
8320 	ASSERT_RTNL();
8321 	changelowerstate_info.lower_state_info = lower_state_info;
8322 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8323 				      &changelowerstate_info.info);
8324 }
8325 EXPORT_SYMBOL(netdev_lower_state_changed);
8326 
8327 static void dev_change_rx_flags(struct net_device *dev, int flags)
8328 {
8329 	const struct net_device_ops *ops = dev->netdev_ops;
8330 
8331 	if (ops->ndo_change_rx_flags)
8332 		ops->ndo_change_rx_flags(dev, flags);
8333 }
8334 
8335 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8336 {
8337 	unsigned int old_flags = dev->flags;
8338 	kuid_t uid;
8339 	kgid_t gid;
8340 
8341 	ASSERT_RTNL();
8342 
8343 	dev->flags |= IFF_PROMISC;
8344 	dev->promiscuity += inc;
8345 	if (dev->promiscuity == 0) {
8346 		/*
8347 		 * Avoid overflow.
8348 		 * If inc causes overflow, untouch promisc and return error.
8349 		 */
8350 		if (inc < 0)
8351 			dev->flags &= ~IFF_PROMISC;
8352 		else {
8353 			dev->promiscuity -= inc;
8354 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8355 			return -EOVERFLOW;
8356 		}
8357 	}
8358 	if (dev->flags != old_flags) {
8359 		netdev_info(dev, "%s promiscuous mode\n",
8360 			    dev->flags & IFF_PROMISC ? "entered" : "left");
8361 		if (audit_enabled) {
8362 			current_uid_gid(&uid, &gid);
8363 			audit_log(audit_context(), GFP_ATOMIC,
8364 				  AUDIT_ANOM_PROMISCUOUS,
8365 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8366 				  dev->name, (dev->flags & IFF_PROMISC),
8367 				  (old_flags & IFF_PROMISC),
8368 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8369 				  from_kuid(&init_user_ns, uid),
8370 				  from_kgid(&init_user_ns, gid),
8371 				  audit_get_sessionid(current));
8372 		}
8373 
8374 		dev_change_rx_flags(dev, IFF_PROMISC);
8375 	}
8376 	if (notify)
8377 		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8378 	return 0;
8379 }
8380 
8381 /**
8382  *	dev_set_promiscuity	- update promiscuity count on a device
8383  *	@dev: device
8384  *	@inc: modifier
8385  *
8386  *	Add or remove promiscuity from a device. While the count in the device
8387  *	remains above zero the interface remains promiscuous. Once it hits zero
8388  *	the device reverts back to normal filtering operation. A negative inc
8389  *	value is used to drop promiscuity on the device.
8390  *	Return 0 if successful or a negative errno code on error.
8391  */
8392 int dev_set_promiscuity(struct net_device *dev, int inc)
8393 {
8394 	unsigned int old_flags = dev->flags;
8395 	int err;
8396 
8397 	err = __dev_set_promiscuity(dev, inc, true);
8398 	if (err < 0)
8399 		return err;
8400 	if (dev->flags != old_flags)
8401 		dev_set_rx_mode(dev);
8402 	return err;
8403 }
8404 EXPORT_SYMBOL(dev_set_promiscuity);
8405 
8406 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8407 {
8408 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8409 
8410 	ASSERT_RTNL();
8411 
8412 	dev->flags |= IFF_ALLMULTI;
8413 	dev->allmulti += inc;
8414 	if (dev->allmulti == 0) {
8415 		/*
8416 		 * Avoid overflow.
8417 		 * If inc causes overflow, untouch allmulti and return error.
8418 		 */
8419 		if (inc < 0)
8420 			dev->flags &= ~IFF_ALLMULTI;
8421 		else {
8422 			dev->allmulti -= inc;
8423 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8424 			return -EOVERFLOW;
8425 		}
8426 	}
8427 	if (dev->flags ^ old_flags) {
8428 		netdev_info(dev, "%s allmulticast mode\n",
8429 			    dev->flags & IFF_ALLMULTI ? "entered" : "left");
8430 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8431 		dev_set_rx_mode(dev);
8432 		if (notify)
8433 			__dev_notify_flags(dev, old_flags,
8434 					   dev->gflags ^ old_gflags, 0, NULL);
8435 	}
8436 	return 0;
8437 }
8438 
8439 /**
8440  *	dev_set_allmulti	- update allmulti count on a device
8441  *	@dev: device
8442  *	@inc: modifier
8443  *
8444  *	Add or remove reception of all multicast frames to a device. While the
8445  *	count in the device remains above zero the interface remains listening
8446  *	to all interfaces. Once it hits zero the device reverts back to normal
8447  *	filtering operation. A negative @inc value is used to drop the counter
8448  *	when releasing a resource needing all multicasts.
8449  *	Return 0 if successful or a negative errno code on error.
8450  */
8451 
8452 int dev_set_allmulti(struct net_device *dev, int inc)
8453 {
8454 	return __dev_set_allmulti(dev, inc, true);
8455 }
8456 EXPORT_SYMBOL(dev_set_allmulti);
8457 
8458 /*
8459  *	Upload unicast and multicast address lists to device and
8460  *	configure RX filtering. When the device doesn't support unicast
8461  *	filtering it is put in promiscuous mode while unicast addresses
8462  *	are present.
8463  */
8464 void __dev_set_rx_mode(struct net_device *dev)
8465 {
8466 	const struct net_device_ops *ops = dev->netdev_ops;
8467 
8468 	/* dev_open will call this function so the list will stay sane. */
8469 	if (!(dev->flags&IFF_UP))
8470 		return;
8471 
8472 	if (!netif_device_present(dev))
8473 		return;
8474 
8475 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8476 		/* Unicast addresses changes may only happen under the rtnl,
8477 		 * therefore calling __dev_set_promiscuity here is safe.
8478 		 */
8479 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8480 			__dev_set_promiscuity(dev, 1, false);
8481 			dev->uc_promisc = true;
8482 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8483 			__dev_set_promiscuity(dev, -1, false);
8484 			dev->uc_promisc = false;
8485 		}
8486 	}
8487 
8488 	if (ops->ndo_set_rx_mode)
8489 		ops->ndo_set_rx_mode(dev);
8490 }
8491 
8492 void dev_set_rx_mode(struct net_device *dev)
8493 {
8494 	netif_addr_lock_bh(dev);
8495 	__dev_set_rx_mode(dev);
8496 	netif_addr_unlock_bh(dev);
8497 }
8498 
8499 /**
8500  *	dev_get_flags - get flags reported to userspace
8501  *	@dev: device
8502  *
8503  *	Get the combination of flag bits exported through APIs to userspace.
8504  */
8505 unsigned int dev_get_flags(const struct net_device *dev)
8506 {
8507 	unsigned int flags;
8508 
8509 	flags = (dev->flags & ~(IFF_PROMISC |
8510 				IFF_ALLMULTI |
8511 				IFF_RUNNING |
8512 				IFF_LOWER_UP |
8513 				IFF_DORMANT)) |
8514 		(dev->gflags & (IFF_PROMISC |
8515 				IFF_ALLMULTI));
8516 
8517 	if (netif_running(dev)) {
8518 		if (netif_oper_up(dev))
8519 			flags |= IFF_RUNNING;
8520 		if (netif_carrier_ok(dev))
8521 			flags |= IFF_LOWER_UP;
8522 		if (netif_dormant(dev))
8523 			flags |= IFF_DORMANT;
8524 	}
8525 
8526 	return flags;
8527 }
8528 EXPORT_SYMBOL(dev_get_flags);
8529 
8530 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8531 		       struct netlink_ext_ack *extack)
8532 {
8533 	unsigned int old_flags = dev->flags;
8534 	int ret;
8535 
8536 	ASSERT_RTNL();
8537 
8538 	/*
8539 	 *	Set the flags on our device.
8540 	 */
8541 
8542 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8543 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8544 			       IFF_AUTOMEDIA)) |
8545 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8546 				    IFF_ALLMULTI));
8547 
8548 	/*
8549 	 *	Load in the correct multicast list now the flags have changed.
8550 	 */
8551 
8552 	if ((old_flags ^ flags) & IFF_MULTICAST)
8553 		dev_change_rx_flags(dev, IFF_MULTICAST);
8554 
8555 	dev_set_rx_mode(dev);
8556 
8557 	/*
8558 	 *	Have we downed the interface. We handle IFF_UP ourselves
8559 	 *	according to user attempts to set it, rather than blindly
8560 	 *	setting it.
8561 	 */
8562 
8563 	ret = 0;
8564 	if ((old_flags ^ flags) & IFF_UP) {
8565 		if (old_flags & IFF_UP)
8566 			__dev_close(dev);
8567 		else
8568 			ret = __dev_open(dev, extack);
8569 	}
8570 
8571 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8572 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8573 		unsigned int old_flags = dev->flags;
8574 
8575 		dev->gflags ^= IFF_PROMISC;
8576 
8577 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8578 			if (dev->flags != old_flags)
8579 				dev_set_rx_mode(dev);
8580 	}
8581 
8582 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8583 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8584 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8585 	 */
8586 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8587 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8588 
8589 		dev->gflags ^= IFF_ALLMULTI;
8590 		__dev_set_allmulti(dev, inc, false);
8591 	}
8592 
8593 	return ret;
8594 }
8595 
8596 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8597 			unsigned int gchanges, u32 portid,
8598 			const struct nlmsghdr *nlh)
8599 {
8600 	unsigned int changes = dev->flags ^ old_flags;
8601 
8602 	if (gchanges)
8603 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8604 
8605 	if (changes & IFF_UP) {
8606 		if (dev->flags & IFF_UP)
8607 			call_netdevice_notifiers(NETDEV_UP, dev);
8608 		else
8609 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8610 	}
8611 
8612 	if (dev->flags & IFF_UP &&
8613 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8614 		struct netdev_notifier_change_info change_info = {
8615 			.info = {
8616 				.dev = dev,
8617 			},
8618 			.flags_changed = changes,
8619 		};
8620 
8621 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8622 	}
8623 }
8624 
8625 /**
8626  *	dev_change_flags - change device settings
8627  *	@dev: device
8628  *	@flags: device state flags
8629  *	@extack: netlink extended ack
8630  *
8631  *	Change settings on device based state flags. The flags are
8632  *	in the userspace exported format.
8633  */
8634 int dev_change_flags(struct net_device *dev, unsigned int flags,
8635 		     struct netlink_ext_ack *extack)
8636 {
8637 	int ret;
8638 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8639 
8640 	ret = __dev_change_flags(dev, flags, extack);
8641 	if (ret < 0)
8642 		return ret;
8643 
8644 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8645 	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
8646 	return ret;
8647 }
8648 EXPORT_SYMBOL(dev_change_flags);
8649 
8650 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8651 {
8652 	const struct net_device_ops *ops = dev->netdev_ops;
8653 
8654 	if (ops->ndo_change_mtu)
8655 		return ops->ndo_change_mtu(dev, new_mtu);
8656 
8657 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8658 	WRITE_ONCE(dev->mtu, new_mtu);
8659 	return 0;
8660 }
8661 EXPORT_SYMBOL(__dev_set_mtu);
8662 
8663 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8664 		     struct netlink_ext_ack *extack)
8665 {
8666 	/* MTU must be positive, and in range */
8667 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8668 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8669 		return -EINVAL;
8670 	}
8671 
8672 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8673 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8674 		return -EINVAL;
8675 	}
8676 	return 0;
8677 }
8678 
8679 /**
8680  *	dev_set_mtu_ext - Change maximum transfer unit
8681  *	@dev: device
8682  *	@new_mtu: new transfer unit
8683  *	@extack: netlink extended ack
8684  *
8685  *	Change the maximum transfer size of the network device.
8686  */
8687 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8688 		    struct netlink_ext_ack *extack)
8689 {
8690 	int err, orig_mtu;
8691 
8692 	if (new_mtu == dev->mtu)
8693 		return 0;
8694 
8695 	err = dev_validate_mtu(dev, new_mtu, extack);
8696 	if (err)
8697 		return err;
8698 
8699 	if (!netif_device_present(dev))
8700 		return -ENODEV;
8701 
8702 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8703 	err = notifier_to_errno(err);
8704 	if (err)
8705 		return err;
8706 
8707 	orig_mtu = dev->mtu;
8708 	err = __dev_set_mtu(dev, new_mtu);
8709 
8710 	if (!err) {
8711 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8712 						   orig_mtu);
8713 		err = notifier_to_errno(err);
8714 		if (err) {
8715 			/* setting mtu back and notifying everyone again,
8716 			 * so that they have a chance to revert changes.
8717 			 */
8718 			__dev_set_mtu(dev, orig_mtu);
8719 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8720 						     new_mtu);
8721 		}
8722 	}
8723 	return err;
8724 }
8725 
8726 int dev_set_mtu(struct net_device *dev, int new_mtu)
8727 {
8728 	struct netlink_ext_ack extack;
8729 	int err;
8730 
8731 	memset(&extack, 0, sizeof(extack));
8732 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
8733 	if (err && extack._msg)
8734 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8735 	return err;
8736 }
8737 EXPORT_SYMBOL(dev_set_mtu);
8738 
8739 /**
8740  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
8741  *	@dev: device
8742  *	@new_len: new tx queue length
8743  */
8744 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8745 {
8746 	unsigned int orig_len = dev->tx_queue_len;
8747 	int res;
8748 
8749 	if (new_len != (unsigned int)new_len)
8750 		return -ERANGE;
8751 
8752 	if (new_len != orig_len) {
8753 		dev->tx_queue_len = new_len;
8754 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8755 		res = notifier_to_errno(res);
8756 		if (res)
8757 			goto err_rollback;
8758 		res = dev_qdisc_change_tx_queue_len(dev);
8759 		if (res)
8760 			goto err_rollback;
8761 	}
8762 
8763 	return 0;
8764 
8765 err_rollback:
8766 	netdev_err(dev, "refused to change device tx_queue_len\n");
8767 	dev->tx_queue_len = orig_len;
8768 	return res;
8769 }
8770 
8771 /**
8772  *	dev_set_group - Change group this device belongs to
8773  *	@dev: device
8774  *	@new_group: group this device should belong to
8775  */
8776 void dev_set_group(struct net_device *dev, int new_group)
8777 {
8778 	dev->group = new_group;
8779 }
8780 
8781 /**
8782  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8783  *	@dev: device
8784  *	@addr: new address
8785  *	@extack: netlink extended ack
8786  */
8787 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8788 			      struct netlink_ext_ack *extack)
8789 {
8790 	struct netdev_notifier_pre_changeaddr_info info = {
8791 		.info.dev = dev,
8792 		.info.extack = extack,
8793 		.dev_addr = addr,
8794 	};
8795 	int rc;
8796 
8797 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8798 	return notifier_to_errno(rc);
8799 }
8800 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8801 
8802 /**
8803  *	dev_set_mac_address - Change Media Access Control Address
8804  *	@dev: device
8805  *	@sa: new address
8806  *	@extack: netlink extended ack
8807  *
8808  *	Change the hardware (MAC) address of the device
8809  */
8810 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8811 			struct netlink_ext_ack *extack)
8812 {
8813 	const struct net_device_ops *ops = dev->netdev_ops;
8814 	int err;
8815 
8816 	if (!ops->ndo_set_mac_address)
8817 		return -EOPNOTSUPP;
8818 	if (sa->sa_family != dev->type)
8819 		return -EINVAL;
8820 	if (!netif_device_present(dev))
8821 		return -ENODEV;
8822 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8823 	if (err)
8824 		return err;
8825 	err = ops->ndo_set_mac_address(dev, sa);
8826 	if (err)
8827 		return err;
8828 	dev->addr_assign_type = NET_ADDR_SET;
8829 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8830 	add_device_randomness(dev->dev_addr, dev->addr_len);
8831 	return 0;
8832 }
8833 EXPORT_SYMBOL(dev_set_mac_address);
8834 
8835 static DECLARE_RWSEM(dev_addr_sem);
8836 
8837 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8838 			     struct netlink_ext_ack *extack)
8839 {
8840 	int ret;
8841 
8842 	down_write(&dev_addr_sem);
8843 	ret = dev_set_mac_address(dev, sa, extack);
8844 	up_write(&dev_addr_sem);
8845 	return ret;
8846 }
8847 EXPORT_SYMBOL(dev_set_mac_address_user);
8848 
8849 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8850 {
8851 	size_t size = sizeof(sa->sa_data_min);
8852 	struct net_device *dev;
8853 	int ret = 0;
8854 
8855 	down_read(&dev_addr_sem);
8856 	rcu_read_lock();
8857 
8858 	dev = dev_get_by_name_rcu(net, dev_name);
8859 	if (!dev) {
8860 		ret = -ENODEV;
8861 		goto unlock;
8862 	}
8863 	if (!dev->addr_len)
8864 		memset(sa->sa_data, 0, size);
8865 	else
8866 		memcpy(sa->sa_data, dev->dev_addr,
8867 		       min_t(size_t, size, dev->addr_len));
8868 	sa->sa_family = dev->type;
8869 
8870 unlock:
8871 	rcu_read_unlock();
8872 	up_read(&dev_addr_sem);
8873 	return ret;
8874 }
8875 EXPORT_SYMBOL(dev_get_mac_address);
8876 
8877 /**
8878  *	dev_change_carrier - Change device carrier
8879  *	@dev: device
8880  *	@new_carrier: new value
8881  *
8882  *	Change device carrier
8883  */
8884 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8885 {
8886 	const struct net_device_ops *ops = dev->netdev_ops;
8887 
8888 	if (!ops->ndo_change_carrier)
8889 		return -EOPNOTSUPP;
8890 	if (!netif_device_present(dev))
8891 		return -ENODEV;
8892 	return ops->ndo_change_carrier(dev, new_carrier);
8893 }
8894 
8895 /**
8896  *	dev_get_phys_port_id - Get device physical port ID
8897  *	@dev: device
8898  *	@ppid: port ID
8899  *
8900  *	Get device physical port ID
8901  */
8902 int dev_get_phys_port_id(struct net_device *dev,
8903 			 struct netdev_phys_item_id *ppid)
8904 {
8905 	const struct net_device_ops *ops = dev->netdev_ops;
8906 
8907 	if (!ops->ndo_get_phys_port_id)
8908 		return -EOPNOTSUPP;
8909 	return ops->ndo_get_phys_port_id(dev, ppid);
8910 }
8911 
8912 /**
8913  *	dev_get_phys_port_name - Get device physical port name
8914  *	@dev: device
8915  *	@name: port name
8916  *	@len: limit of bytes to copy to name
8917  *
8918  *	Get device physical port name
8919  */
8920 int dev_get_phys_port_name(struct net_device *dev,
8921 			   char *name, size_t len)
8922 {
8923 	const struct net_device_ops *ops = dev->netdev_ops;
8924 	int err;
8925 
8926 	if (ops->ndo_get_phys_port_name) {
8927 		err = ops->ndo_get_phys_port_name(dev, name, len);
8928 		if (err != -EOPNOTSUPP)
8929 			return err;
8930 	}
8931 	return devlink_compat_phys_port_name_get(dev, name, len);
8932 }
8933 
8934 /**
8935  *	dev_get_port_parent_id - Get the device's port parent identifier
8936  *	@dev: network device
8937  *	@ppid: pointer to a storage for the port's parent identifier
8938  *	@recurse: allow/disallow recursion to lower devices
8939  *
8940  *	Get the devices's port parent identifier
8941  */
8942 int dev_get_port_parent_id(struct net_device *dev,
8943 			   struct netdev_phys_item_id *ppid,
8944 			   bool recurse)
8945 {
8946 	const struct net_device_ops *ops = dev->netdev_ops;
8947 	struct netdev_phys_item_id first = { };
8948 	struct net_device *lower_dev;
8949 	struct list_head *iter;
8950 	int err;
8951 
8952 	if (ops->ndo_get_port_parent_id) {
8953 		err = ops->ndo_get_port_parent_id(dev, ppid);
8954 		if (err != -EOPNOTSUPP)
8955 			return err;
8956 	}
8957 
8958 	err = devlink_compat_switch_id_get(dev, ppid);
8959 	if (!recurse || err != -EOPNOTSUPP)
8960 		return err;
8961 
8962 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
8963 		err = dev_get_port_parent_id(lower_dev, ppid, true);
8964 		if (err)
8965 			break;
8966 		if (!first.id_len)
8967 			first = *ppid;
8968 		else if (memcmp(&first, ppid, sizeof(*ppid)))
8969 			return -EOPNOTSUPP;
8970 	}
8971 
8972 	return err;
8973 }
8974 EXPORT_SYMBOL(dev_get_port_parent_id);
8975 
8976 /**
8977  *	netdev_port_same_parent_id - Indicate if two network devices have
8978  *	the same port parent identifier
8979  *	@a: first network device
8980  *	@b: second network device
8981  */
8982 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
8983 {
8984 	struct netdev_phys_item_id a_id = { };
8985 	struct netdev_phys_item_id b_id = { };
8986 
8987 	if (dev_get_port_parent_id(a, &a_id, true) ||
8988 	    dev_get_port_parent_id(b, &b_id, true))
8989 		return false;
8990 
8991 	return netdev_phys_item_id_same(&a_id, &b_id);
8992 }
8993 EXPORT_SYMBOL(netdev_port_same_parent_id);
8994 
8995 /**
8996  *	dev_change_proto_down - set carrier according to proto_down.
8997  *
8998  *	@dev: device
8999  *	@proto_down: new value
9000  */
9001 int dev_change_proto_down(struct net_device *dev, bool proto_down)
9002 {
9003 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
9004 		return -EOPNOTSUPP;
9005 	if (!netif_device_present(dev))
9006 		return -ENODEV;
9007 	if (proto_down)
9008 		netif_carrier_off(dev);
9009 	else
9010 		netif_carrier_on(dev);
9011 	dev->proto_down = proto_down;
9012 	return 0;
9013 }
9014 
9015 /**
9016  *	dev_change_proto_down_reason - proto down reason
9017  *
9018  *	@dev: device
9019  *	@mask: proto down mask
9020  *	@value: proto down value
9021  */
9022 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9023 				  u32 value)
9024 {
9025 	int b;
9026 
9027 	if (!mask) {
9028 		dev->proto_down_reason = value;
9029 	} else {
9030 		for_each_set_bit(b, &mask, 32) {
9031 			if (value & (1 << b))
9032 				dev->proto_down_reason |= BIT(b);
9033 			else
9034 				dev->proto_down_reason &= ~BIT(b);
9035 		}
9036 	}
9037 }
9038 
9039 struct bpf_xdp_link {
9040 	struct bpf_link link;
9041 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9042 	int flags;
9043 };
9044 
9045 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9046 {
9047 	if (flags & XDP_FLAGS_HW_MODE)
9048 		return XDP_MODE_HW;
9049 	if (flags & XDP_FLAGS_DRV_MODE)
9050 		return XDP_MODE_DRV;
9051 	if (flags & XDP_FLAGS_SKB_MODE)
9052 		return XDP_MODE_SKB;
9053 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9054 }
9055 
9056 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9057 {
9058 	switch (mode) {
9059 	case XDP_MODE_SKB:
9060 		return generic_xdp_install;
9061 	case XDP_MODE_DRV:
9062 	case XDP_MODE_HW:
9063 		return dev->netdev_ops->ndo_bpf;
9064 	default:
9065 		return NULL;
9066 	}
9067 }
9068 
9069 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9070 					 enum bpf_xdp_mode mode)
9071 {
9072 	return dev->xdp_state[mode].link;
9073 }
9074 
9075 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9076 				     enum bpf_xdp_mode mode)
9077 {
9078 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9079 
9080 	if (link)
9081 		return link->link.prog;
9082 	return dev->xdp_state[mode].prog;
9083 }
9084 
9085 u8 dev_xdp_prog_count(struct net_device *dev)
9086 {
9087 	u8 count = 0;
9088 	int i;
9089 
9090 	for (i = 0; i < __MAX_XDP_MODE; i++)
9091 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9092 			count++;
9093 	return count;
9094 }
9095 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9096 
9097 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9098 {
9099 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9100 
9101 	return prog ? prog->aux->id : 0;
9102 }
9103 
9104 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9105 			     struct bpf_xdp_link *link)
9106 {
9107 	dev->xdp_state[mode].link = link;
9108 	dev->xdp_state[mode].prog = NULL;
9109 }
9110 
9111 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9112 			     struct bpf_prog *prog)
9113 {
9114 	dev->xdp_state[mode].link = NULL;
9115 	dev->xdp_state[mode].prog = prog;
9116 }
9117 
9118 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9119 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9120 			   u32 flags, struct bpf_prog *prog)
9121 {
9122 	struct netdev_bpf xdp;
9123 	int err;
9124 
9125 	memset(&xdp, 0, sizeof(xdp));
9126 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9127 	xdp.extack = extack;
9128 	xdp.flags = flags;
9129 	xdp.prog = prog;
9130 
9131 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9132 	 * "moved" into driver), so they don't increment it on their own, but
9133 	 * they do decrement refcnt when program is detached or replaced.
9134 	 * Given net_device also owns link/prog, we need to bump refcnt here
9135 	 * to prevent drivers from underflowing it.
9136 	 */
9137 	if (prog)
9138 		bpf_prog_inc(prog);
9139 	err = bpf_op(dev, &xdp);
9140 	if (err) {
9141 		if (prog)
9142 			bpf_prog_put(prog);
9143 		return err;
9144 	}
9145 
9146 	if (mode != XDP_MODE_HW)
9147 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9148 
9149 	return 0;
9150 }
9151 
9152 static void dev_xdp_uninstall(struct net_device *dev)
9153 {
9154 	struct bpf_xdp_link *link;
9155 	struct bpf_prog *prog;
9156 	enum bpf_xdp_mode mode;
9157 	bpf_op_t bpf_op;
9158 
9159 	ASSERT_RTNL();
9160 
9161 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9162 		prog = dev_xdp_prog(dev, mode);
9163 		if (!prog)
9164 			continue;
9165 
9166 		bpf_op = dev_xdp_bpf_op(dev, mode);
9167 		if (!bpf_op)
9168 			continue;
9169 
9170 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9171 
9172 		/* auto-detach link from net device */
9173 		link = dev_xdp_link(dev, mode);
9174 		if (link)
9175 			link->dev = NULL;
9176 		else
9177 			bpf_prog_put(prog);
9178 
9179 		dev_xdp_set_link(dev, mode, NULL);
9180 	}
9181 }
9182 
9183 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9184 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9185 			  struct bpf_prog *old_prog, u32 flags)
9186 {
9187 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9188 	struct bpf_prog *cur_prog;
9189 	struct net_device *upper;
9190 	struct list_head *iter;
9191 	enum bpf_xdp_mode mode;
9192 	bpf_op_t bpf_op;
9193 	int err;
9194 
9195 	ASSERT_RTNL();
9196 
9197 	/* either link or prog attachment, never both */
9198 	if (link && (new_prog || old_prog))
9199 		return -EINVAL;
9200 	/* link supports only XDP mode flags */
9201 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9202 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9203 		return -EINVAL;
9204 	}
9205 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9206 	if (num_modes > 1) {
9207 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9208 		return -EINVAL;
9209 	}
9210 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9211 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9212 		NL_SET_ERR_MSG(extack,
9213 			       "More than one program loaded, unset mode is ambiguous");
9214 		return -EINVAL;
9215 	}
9216 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9217 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9218 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9219 		return -EINVAL;
9220 	}
9221 
9222 	mode = dev_xdp_mode(dev, flags);
9223 	/* can't replace attached link */
9224 	if (dev_xdp_link(dev, mode)) {
9225 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9226 		return -EBUSY;
9227 	}
9228 
9229 	/* don't allow if an upper device already has a program */
9230 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9231 		if (dev_xdp_prog_count(upper) > 0) {
9232 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9233 			return -EEXIST;
9234 		}
9235 	}
9236 
9237 	cur_prog = dev_xdp_prog(dev, mode);
9238 	/* can't replace attached prog with link */
9239 	if (link && cur_prog) {
9240 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9241 		return -EBUSY;
9242 	}
9243 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9244 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9245 		return -EEXIST;
9246 	}
9247 
9248 	/* put effective new program into new_prog */
9249 	if (link)
9250 		new_prog = link->link.prog;
9251 
9252 	if (new_prog) {
9253 		bool offload = mode == XDP_MODE_HW;
9254 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9255 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9256 
9257 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9258 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9259 			return -EBUSY;
9260 		}
9261 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9262 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9263 			return -EEXIST;
9264 		}
9265 		if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
9266 			NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
9267 			return -EINVAL;
9268 		}
9269 		if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
9270 			NL_SET_ERR_MSG(extack, "Program bound to different device");
9271 			return -EINVAL;
9272 		}
9273 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9274 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9275 			return -EINVAL;
9276 		}
9277 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9278 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9279 			return -EINVAL;
9280 		}
9281 	}
9282 
9283 	/* don't call drivers if the effective program didn't change */
9284 	if (new_prog != cur_prog) {
9285 		bpf_op = dev_xdp_bpf_op(dev, mode);
9286 		if (!bpf_op) {
9287 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9288 			return -EOPNOTSUPP;
9289 		}
9290 
9291 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9292 		if (err)
9293 			return err;
9294 	}
9295 
9296 	if (link)
9297 		dev_xdp_set_link(dev, mode, link);
9298 	else
9299 		dev_xdp_set_prog(dev, mode, new_prog);
9300 	if (cur_prog)
9301 		bpf_prog_put(cur_prog);
9302 
9303 	return 0;
9304 }
9305 
9306 static int dev_xdp_attach_link(struct net_device *dev,
9307 			       struct netlink_ext_ack *extack,
9308 			       struct bpf_xdp_link *link)
9309 {
9310 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9311 }
9312 
9313 static int dev_xdp_detach_link(struct net_device *dev,
9314 			       struct netlink_ext_ack *extack,
9315 			       struct bpf_xdp_link *link)
9316 {
9317 	enum bpf_xdp_mode mode;
9318 	bpf_op_t bpf_op;
9319 
9320 	ASSERT_RTNL();
9321 
9322 	mode = dev_xdp_mode(dev, link->flags);
9323 	if (dev_xdp_link(dev, mode) != link)
9324 		return -EINVAL;
9325 
9326 	bpf_op = dev_xdp_bpf_op(dev, mode);
9327 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9328 	dev_xdp_set_link(dev, mode, NULL);
9329 	return 0;
9330 }
9331 
9332 static void bpf_xdp_link_release(struct bpf_link *link)
9333 {
9334 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9335 
9336 	rtnl_lock();
9337 
9338 	/* if racing with net_device's tear down, xdp_link->dev might be
9339 	 * already NULL, in which case link was already auto-detached
9340 	 */
9341 	if (xdp_link->dev) {
9342 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9343 		xdp_link->dev = NULL;
9344 	}
9345 
9346 	rtnl_unlock();
9347 }
9348 
9349 static int bpf_xdp_link_detach(struct bpf_link *link)
9350 {
9351 	bpf_xdp_link_release(link);
9352 	return 0;
9353 }
9354 
9355 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9356 {
9357 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9358 
9359 	kfree(xdp_link);
9360 }
9361 
9362 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9363 				     struct seq_file *seq)
9364 {
9365 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9366 	u32 ifindex = 0;
9367 
9368 	rtnl_lock();
9369 	if (xdp_link->dev)
9370 		ifindex = xdp_link->dev->ifindex;
9371 	rtnl_unlock();
9372 
9373 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9374 }
9375 
9376 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9377 				       struct bpf_link_info *info)
9378 {
9379 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9380 	u32 ifindex = 0;
9381 
9382 	rtnl_lock();
9383 	if (xdp_link->dev)
9384 		ifindex = xdp_link->dev->ifindex;
9385 	rtnl_unlock();
9386 
9387 	info->xdp.ifindex = ifindex;
9388 	return 0;
9389 }
9390 
9391 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9392 			       struct bpf_prog *old_prog)
9393 {
9394 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9395 	enum bpf_xdp_mode mode;
9396 	bpf_op_t bpf_op;
9397 	int err = 0;
9398 
9399 	rtnl_lock();
9400 
9401 	/* link might have been auto-released already, so fail */
9402 	if (!xdp_link->dev) {
9403 		err = -ENOLINK;
9404 		goto out_unlock;
9405 	}
9406 
9407 	if (old_prog && link->prog != old_prog) {
9408 		err = -EPERM;
9409 		goto out_unlock;
9410 	}
9411 	old_prog = link->prog;
9412 	if (old_prog->type != new_prog->type ||
9413 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9414 		err = -EINVAL;
9415 		goto out_unlock;
9416 	}
9417 
9418 	if (old_prog == new_prog) {
9419 		/* no-op, don't disturb drivers */
9420 		bpf_prog_put(new_prog);
9421 		goto out_unlock;
9422 	}
9423 
9424 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9425 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9426 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9427 			      xdp_link->flags, new_prog);
9428 	if (err)
9429 		goto out_unlock;
9430 
9431 	old_prog = xchg(&link->prog, new_prog);
9432 	bpf_prog_put(old_prog);
9433 
9434 out_unlock:
9435 	rtnl_unlock();
9436 	return err;
9437 }
9438 
9439 static const struct bpf_link_ops bpf_xdp_link_lops = {
9440 	.release = bpf_xdp_link_release,
9441 	.dealloc = bpf_xdp_link_dealloc,
9442 	.detach = bpf_xdp_link_detach,
9443 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9444 	.fill_link_info = bpf_xdp_link_fill_link_info,
9445 	.update_prog = bpf_xdp_link_update,
9446 };
9447 
9448 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9449 {
9450 	struct net *net = current->nsproxy->net_ns;
9451 	struct bpf_link_primer link_primer;
9452 	struct bpf_xdp_link *link;
9453 	struct net_device *dev;
9454 	int err, fd;
9455 
9456 	rtnl_lock();
9457 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9458 	if (!dev) {
9459 		rtnl_unlock();
9460 		return -EINVAL;
9461 	}
9462 
9463 	link = kzalloc(sizeof(*link), GFP_USER);
9464 	if (!link) {
9465 		err = -ENOMEM;
9466 		goto unlock;
9467 	}
9468 
9469 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9470 	link->dev = dev;
9471 	link->flags = attr->link_create.flags;
9472 
9473 	err = bpf_link_prime(&link->link, &link_primer);
9474 	if (err) {
9475 		kfree(link);
9476 		goto unlock;
9477 	}
9478 
9479 	err = dev_xdp_attach_link(dev, NULL, link);
9480 	rtnl_unlock();
9481 
9482 	if (err) {
9483 		link->dev = NULL;
9484 		bpf_link_cleanup(&link_primer);
9485 		goto out_put_dev;
9486 	}
9487 
9488 	fd = bpf_link_settle(&link_primer);
9489 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9490 	dev_put(dev);
9491 	return fd;
9492 
9493 unlock:
9494 	rtnl_unlock();
9495 
9496 out_put_dev:
9497 	dev_put(dev);
9498 	return err;
9499 }
9500 
9501 /**
9502  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9503  *	@dev: device
9504  *	@extack: netlink extended ack
9505  *	@fd: new program fd or negative value to clear
9506  *	@expected_fd: old program fd that userspace expects to replace or clear
9507  *	@flags: xdp-related flags
9508  *
9509  *	Set or clear a bpf program for a device
9510  */
9511 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9512 		      int fd, int expected_fd, u32 flags)
9513 {
9514 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9515 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9516 	int err;
9517 
9518 	ASSERT_RTNL();
9519 
9520 	if (fd >= 0) {
9521 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9522 						 mode != XDP_MODE_SKB);
9523 		if (IS_ERR(new_prog))
9524 			return PTR_ERR(new_prog);
9525 	}
9526 
9527 	if (expected_fd >= 0) {
9528 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9529 						 mode != XDP_MODE_SKB);
9530 		if (IS_ERR(old_prog)) {
9531 			err = PTR_ERR(old_prog);
9532 			old_prog = NULL;
9533 			goto err_out;
9534 		}
9535 	}
9536 
9537 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9538 
9539 err_out:
9540 	if (err && new_prog)
9541 		bpf_prog_put(new_prog);
9542 	if (old_prog)
9543 		bpf_prog_put(old_prog);
9544 	return err;
9545 }
9546 
9547 /**
9548  *	dev_new_index	-	allocate an ifindex
9549  *	@net: the applicable net namespace
9550  *
9551  *	Returns a suitable unique value for a new device interface
9552  *	number.  The caller must hold the rtnl semaphore or the
9553  *	dev_base_lock to be sure it remains unique.
9554  */
9555 static int dev_new_index(struct net *net)
9556 {
9557 	int ifindex = net->ifindex;
9558 
9559 	for (;;) {
9560 		if (++ifindex <= 0)
9561 			ifindex = 1;
9562 		if (!__dev_get_by_index(net, ifindex))
9563 			return net->ifindex = ifindex;
9564 	}
9565 }
9566 
9567 /* Delayed registration/unregisteration */
9568 LIST_HEAD(net_todo_list);
9569 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9570 
9571 static void net_set_todo(struct net_device *dev)
9572 {
9573 	list_add_tail(&dev->todo_list, &net_todo_list);
9574 	atomic_inc(&dev_net(dev)->dev_unreg_count);
9575 }
9576 
9577 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9578 	struct net_device *upper, netdev_features_t features)
9579 {
9580 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9581 	netdev_features_t feature;
9582 	int feature_bit;
9583 
9584 	for_each_netdev_feature(upper_disables, feature_bit) {
9585 		feature = __NETIF_F_BIT(feature_bit);
9586 		if (!(upper->wanted_features & feature)
9587 		    && (features & feature)) {
9588 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9589 				   &feature, upper->name);
9590 			features &= ~feature;
9591 		}
9592 	}
9593 
9594 	return features;
9595 }
9596 
9597 static void netdev_sync_lower_features(struct net_device *upper,
9598 	struct net_device *lower, netdev_features_t features)
9599 {
9600 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9601 	netdev_features_t feature;
9602 	int feature_bit;
9603 
9604 	for_each_netdev_feature(upper_disables, feature_bit) {
9605 		feature = __NETIF_F_BIT(feature_bit);
9606 		if (!(features & feature) && (lower->features & feature)) {
9607 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9608 				   &feature, lower->name);
9609 			lower->wanted_features &= ~feature;
9610 			__netdev_update_features(lower);
9611 
9612 			if (unlikely(lower->features & feature))
9613 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9614 					    &feature, lower->name);
9615 			else
9616 				netdev_features_change(lower);
9617 		}
9618 	}
9619 }
9620 
9621 static netdev_features_t netdev_fix_features(struct net_device *dev,
9622 	netdev_features_t features)
9623 {
9624 	/* Fix illegal checksum combinations */
9625 	if ((features & NETIF_F_HW_CSUM) &&
9626 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9627 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9628 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9629 	}
9630 
9631 	/* TSO requires that SG is present as well. */
9632 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9633 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9634 		features &= ~NETIF_F_ALL_TSO;
9635 	}
9636 
9637 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9638 					!(features & NETIF_F_IP_CSUM)) {
9639 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9640 		features &= ~NETIF_F_TSO;
9641 		features &= ~NETIF_F_TSO_ECN;
9642 	}
9643 
9644 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9645 					 !(features & NETIF_F_IPV6_CSUM)) {
9646 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9647 		features &= ~NETIF_F_TSO6;
9648 	}
9649 
9650 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9651 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9652 		features &= ~NETIF_F_TSO_MANGLEID;
9653 
9654 	/* TSO ECN requires that TSO is present as well. */
9655 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9656 		features &= ~NETIF_F_TSO_ECN;
9657 
9658 	/* Software GSO depends on SG. */
9659 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9660 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9661 		features &= ~NETIF_F_GSO;
9662 	}
9663 
9664 	/* GSO partial features require GSO partial be set */
9665 	if ((features & dev->gso_partial_features) &&
9666 	    !(features & NETIF_F_GSO_PARTIAL)) {
9667 		netdev_dbg(dev,
9668 			   "Dropping partially supported GSO features since no GSO partial.\n");
9669 		features &= ~dev->gso_partial_features;
9670 	}
9671 
9672 	if (!(features & NETIF_F_RXCSUM)) {
9673 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9674 		 * successfully merged by hardware must also have the
9675 		 * checksum verified by hardware.  If the user does not
9676 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9677 		 */
9678 		if (features & NETIF_F_GRO_HW) {
9679 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9680 			features &= ~NETIF_F_GRO_HW;
9681 		}
9682 	}
9683 
9684 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9685 	if (features & NETIF_F_RXFCS) {
9686 		if (features & NETIF_F_LRO) {
9687 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9688 			features &= ~NETIF_F_LRO;
9689 		}
9690 
9691 		if (features & NETIF_F_GRO_HW) {
9692 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9693 			features &= ~NETIF_F_GRO_HW;
9694 		}
9695 	}
9696 
9697 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9698 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9699 		features &= ~NETIF_F_LRO;
9700 	}
9701 
9702 	if (features & NETIF_F_HW_TLS_TX) {
9703 		bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9704 			(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9705 		bool hw_csum = features & NETIF_F_HW_CSUM;
9706 
9707 		if (!ip_csum && !hw_csum) {
9708 			netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9709 			features &= ~NETIF_F_HW_TLS_TX;
9710 		}
9711 	}
9712 
9713 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9714 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9715 		features &= ~NETIF_F_HW_TLS_RX;
9716 	}
9717 
9718 	return features;
9719 }
9720 
9721 int __netdev_update_features(struct net_device *dev)
9722 {
9723 	struct net_device *upper, *lower;
9724 	netdev_features_t features;
9725 	struct list_head *iter;
9726 	int err = -1;
9727 
9728 	ASSERT_RTNL();
9729 
9730 	features = netdev_get_wanted_features(dev);
9731 
9732 	if (dev->netdev_ops->ndo_fix_features)
9733 		features = dev->netdev_ops->ndo_fix_features(dev, features);
9734 
9735 	/* driver might be less strict about feature dependencies */
9736 	features = netdev_fix_features(dev, features);
9737 
9738 	/* some features can't be enabled if they're off on an upper device */
9739 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
9740 		features = netdev_sync_upper_features(dev, upper, features);
9741 
9742 	if (dev->features == features)
9743 		goto sync_lower;
9744 
9745 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9746 		&dev->features, &features);
9747 
9748 	if (dev->netdev_ops->ndo_set_features)
9749 		err = dev->netdev_ops->ndo_set_features(dev, features);
9750 	else
9751 		err = 0;
9752 
9753 	if (unlikely(err < 0)) {
9754 		netdev_err(dev,
9755 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
9756 			err, &features, &dev->features);
9757 		/* return non-0 since some features might have changed and
9758 		 * it's better to fire a spurious notification than miss it
9759 		 */
9760 		return -1;
9761 	}
9762 
9763 sync_lower:
9764 	/* some features must be disabled on lower devices when disabled
9765 	 * on an upper device (think: bonding master or bridge)
9766 	 */
9767 	netdev_for_each_lower_dev(dev, lower, iter)
9768 		netdev_sync_lower_features(dev, lower, features);
9769 
9770 	if (!err) {
9771 		netdev_features_t diff = features ^ dev->features;
9772 
9773 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9774 			/* udp_tunnel_{get,drop}_rx_info both need
9775 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9776 			 * device, or they won't do anything.
9777 			 * Thus we need to update dev->features
9778 			 * *before* calling udp_tunnel_get_rx_info,
9779 			 * but *after* calling udp_tunnel_drop_rx_info.
9780 			 */
9781 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9782 				dev->features = features;
9783 				udp_tunnel_get_rx_info(dev);
9784 			} else {
9785 				udp_tunnel_drop_rx_info(dev);
9786 			}
9787 		}
9788 
9789 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9790 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9791 				dev->features = features;
9792 				err |= vlan_get_rx_ctag_filter_info(dev);
9793 			} else {
9794 				vlan_drop_rx_ctag_filter_info(dev);
9795 			}
9796 		}
9797 
9798 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9799 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9800 				dev->features = features;
9801 				err |= vlan_get_rx_stag_filter_info(dev);
9802 			} else {
9803 				vlan_drop_rx_stag_filter_info(dev);
9804 			}
9805 		}
9806 
9807 		dev->features = features;
9808 	}
9809 
9810 	return err < 0 ? 0 : 1;
9811 }
9812 
9813 /**
9814  *	netdev_update_features - recalculate device features
9815  *	@dev: the device to check
9816  *
9817  *	Recalculate dev->features set and send notifications if it
9818  *	has changed. Should be called after driver or hardware dependent
9819  *	conditions might have changed that influence the features.
9820  */
9821 void netdev_update_features(struct net_device *dev)
9822 {
9823 	if (__netdev_update_features(dev))
9824 		netdev_features_change(dev);
9825 }
9826 EXPORT_SYMBOL(netdev_update_features);
9827 
9828 /**
9829  *	netdev_change_features - recalculate device features
9830  *	@dev: the device to check
9831  *
9832  *	Recalculate dev->features set and send notifications even
9833  *	if they have not changed. Should be called instead of
9834  *	netdev_update_features() if also dev->vlan_features might
9835  *	have changed to allow the changes to be propagated to stacked
9836  *	VLAN devices.
9837  */
9838 void netdev_change_features(struct net_device *dev)
9839 {
9840 	__netdev_update_features(dev);
9841 	netdev_features_change(dev);
9842 }
9843 EXPORT_SYMBOL(netdev_change_features);
9844 
9845 /**
9846  *	netif_stacked_transfer_operstate -	transfer operstate
9847  *	@rootdev: the root or lower level device to transfer state from
9848  *	@dev: the device to transfer operstate to
9849  *
9850  *	Transfer operational state from root to device. This is normally
9851  *	called when a stacking relationship exists between the root
9852  *	device and the device(a leaf device).
9853  */
9854 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9855 					struct net_device *dev)
9856 {
9857 	if (rootdev->operstate == IF_OPER_DORMANT)
9858 		netif_dormant_on(dev);
9859 	else
9860 		netif_dormant_off(dev);
9861 
9862 	if (rootdev->operstate == IF_OPER_TESTING)
9863 		netif_testing_on(dev);
9864 	else
9865 		netif_testing_off(dev);
9866 
9867 	if (netif_carrier_ok(rootdev))
9868 		netif_carrier_on(dev);
9869 	else
9870 		netif_carrier_off(dev);
9871 }
9872 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9873 
9874 static int netif_alloc_rx_queues(struct net_device *dev)
9875 {
9876 	unsigned int i, count = dev->num_rx_queues;
9877 	struct netdev_rx_queue *rx;
9878 	size_t sz = count * sizeof(*rx);
9879 	int err = 0;
9880 
9881 	BUG_ON(count < 1);
9882 
9883 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9884 	if (!rx)
9885 		return -ENOMEM;
9886 
9887 	dev->_rx = rx;
9888 
9889 	for (i = 0; i < count; i++) {
9890 		rx[i].dev = dev;
9891 
9892 		/* XDP RX-queue setup */
9893 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9894 		if (err < 0)
9895 			goto err_rxq_info;
9896 	}
9897 	return 0;
9898 
9899 err_rxq_info:
9900 	/* Rollback successful reg's and free other resources */
9901 	while (i--)
9902 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9903 	kvfree(dev->_rx);
9904 	dev->_rx = NULL;
9905 	return err;
9906 }
9907 
9908 static void netif_free_rx_queues(struct net_device *dev)
9909 {
9910 	unsigned int i, count = dev->num_rx_queues;
9911 
9912 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9913 	if (!dev->_rx)
9914 		return;
9915 
9916 	for (i = 0; i < count; i++)
9917 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9918 
9919 	kvfree(dev->_rx);
9920 }
9921 
9922 static void netdev_init_one_queue(struct net_device *dev,
9923 				  struct netdev_queue *queue, void *_unused)
9924 {
9925 	/* Initialize queue lock */
9926 	spin_lock_init(&queue->_xmit_lock);
9927 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9928 	queue->xmit_lock_owner = -1;
9929 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9930 	queue->dev = dev;
9931 #ifdef CONFIG_BQL
9932 	dql_init(&queue->dql, HZ);
9933 #endif
9934 }
9935 
9936 static void netif_free_tx_queues(struct net_device *dev)
9937 {
9938 	kvfree(dev->_tx);
9939 }
9940 
9941 static int netif_alloc_netdev_queues(struct net_device *dev)
9942 {
9943 	unsigned int count = dev->num_tx_queues;
9944 	struct netdev_queue *tx;
9945 	size_t sz = count * sizeof(*tx);
9946 
9947 	if (count < 1 || count > 0xffff)
9948 		return -EINVAL;
9949 
9950 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9951 	if (!tx)
9952 		return -ENOMEM;
9953 
9954 	dev->_tx = tx;
9955 
9956 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
9957 	spin_lock_init(&dev->tx_global_lock);
9958 
9959 	return 0;
9960 }
9961 
9962 void netif_tx_stop_all_queues(struct net_device *dev)
9963 {
9964 	unsigned int i;
9965 
9966 	for (i = 0; i < dev->num_tx_queues; i++) {
9967 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
9968 
9969 		netif_tx_stop_queue(txq);
9970 	}
9971 }
9972 EXPORT_SYMBOL(netif_tx_stop_all_queues);
9973 
9974 /**
9975  * register_netdevice() - register a network device
9976  * @dev: device to register
9977  *
9978  * Take a prepared network device structure and make it externally accessible.
9979  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
9980  * Callers must hold the rtnl lock - you may want register_netdev()
9981  * instead of this.
9982  */
9983 int register_netdevice(struct net_device *dev)
9984 {
9985 	int ret;
9986 	struct net *net = dev_net(dev);
9987 
9988 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
9989 		     NETDEV_FEATURE_COUNT);
9990 	BUG_ON(dev_boot_phase);
9991 	ASSERT_RTNL();
9992 
9993 	might_sleep();
9994 
9995 	/* When net_device's are persistent, this will be fatal. */
9996 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
9997 	BUG_ON(!net);
9998 
9999 	ret = ethtool_check_ops(dev->ethtool_ops);
10000 	if (ret)
10001 		return ret;
10002 
10003 	spin_lock_init(&dev->addr_list_lock);
10004 	netdev_set_addr_lockdep_class(dev);
10005 
10006 	ret = dev_get_valid_name(net, dev, dev->name);
10007 	if (ret < 0)
10008 		goto out;
10009 
10010 	ret = -ENOMEM;
10011 	dev->name_node = netdev_name_node_head_alloc(dev);
10012 	if (!dev->name_node)
10013 		goto out;
10014 
10015 	/* Init, if this function is available */
10016 	if (dev->netdev_ops->ndo_init) {
10017 		ret = dev->netdev_ops->ndo_init(dev);
10018 		if (ret) {
10019 			if (ret > 0)
10020 				ret = -EIO;
10021 			goto err_free_name;
10022 		}
10023 	}
10024 
10025 	if (((dev->hw_features | dev->features) &
10026 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
10027 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10028 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10029 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10030 		ret = -EINVAL;
10031 		goto err_uninit;
10032 	}
10033 
10034 	ret = -EBUSY;
10035 	if (!dev->ifindex)
10036 		dev->ifindex = dev_new_index(net);
10037 	else if (__dev_get_by_index(net, dev->ifindex))
10038 		goto err_uninit;
10039 
10040 	/* Transfer changeable features to wanted_features and enable
10041 	 * software offloads (GSO and GRO).
10042 	 */
10043 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10044 	dev->features |= NETIF_F_SOFT_FEATURES;
10045 
10046 	if (dev->udp_tunnel_nic_info) {
10047 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10048 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10049 	}
10050 
10051 	dev->wanted_features = dev->features & dev->hw_features;
10052 
10053 	if (!(dev->flags & IFF_LOOPBACK))
10054 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10055 
10056 	/* If IPv4 TCP segmentation offload is supported we should also
10057 	 * allow the device to enable segmenting the frame with the option
10058 	 * of ignoring a static IP ID value.  This doesn't enable the
10059 	 * feature itself but allows the user to enable it later.
10060 	 */
10061 	if (dev->hw_features & NETIF_F_TSO)
10062 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10063 	if (dev->vlan_features & NETIF_F_TSO)
10064 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10065 	if (dev->mpls_features & NETIF_F_TSO)
10066 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10067 	if (dev->hw_enc_features & NETIF_F_TSO)
10068 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10069 
10070 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10071 	 */
10072 	dev->vlan_features |= NETIF_F_HIGHDMA;
10073 
10074 	/* Make NETIF_F_SG inheritable to tunnel devices.
10075 	 */
10076 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10077 
10078 	/* Make NETIF_F_SG inheritable to MPLS.
10079 	 */
10080 	dev->mpls_features |= NETIF_F_SG;
10081 
10082 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10083 	ret = notifier_to_errno(ret);
10084 	if (ret)
10085 		goto err_uninit;
10086 
10087 	ret = netdev_register_kobject(dev);
10088 	write_lock(&dev_base_lock);
10089 	dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10090 	write_unlock(&dev_base_lock);
10091 	if (ret)
10092 		goto err_uninit_notify;
10093 
10094 	__netdev_update_features(dev);
10095 
10096 	/*
10097 	 *	Default initial state at registry is that the
10098 	 *	device is present.
10099 	 */
10100 
10101 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10102 
10103 	linkwatch_init_dev(dev);
10104 
10105 	dev_init_scheduler(dev);
10106 
10107 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10108 	list_netdevice(dev);
10109 
10110 	add_device_randomness(dev->dev_addr, dev->addr_len);
10111 
10112 	/* If the device has permanent device address, driver should
10113 	 * set dev_addr and also addr_assign_type should be set to
10114 	 * NET_ADDR_PERM (default value).
10115 	 */
10116 	if (dev->addr_assign_type == NET_ADDR_PERM)
10117 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10118 
10119 	/* Notify protocols, that a new device appeared. */
10120 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10121 	ret = notifier_to_errno(ret);
10122 	if (ret) {
10123 		/* Expect explicit free_netdev() on failure */
10124 		dev->needs_free_netdev = false;
10125 		unregister_netdevice_queue(dev, NULL);
10126 		goto out;
10127 	}
10128 	/*
10129 	 *	Prevent userspace races by waiting until the network
10130 	 *	device is fully setup before sending notifications.
10131 	 */
10132 	if (!dev->rtnl_link_ops ||
10133 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10134 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10135 
10136 out:
10137 	return ret;
10138 
10139 err_uninit_notify:
10140 	call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10141 err_uninit:
10142 	if (dev->netdev_ops->ndo_uninit)
10143 		dev->netdev_ops->ndo_uninit(dev);
10144 	if (dev->priv_destructor)
10145 		dev->priv_destructor(dev);
10146 err_free_name:
10147 	netdev_name_node_free(dev->name_node);
10148 	goto out;
10149 }
10150 EXPORT_SYMBOL(register_netdevice);
10151 
10152 /**
10153  *	init_dummy_netdev	- init a dummy network device for NAPI
10154  *	@dev: device to init
10155  *
10156  *	This takes a network device structure and initialize the minimum
10157  *	amount of fields so it can be used to schedule NAPI polls without
10158  *	registering a full blown interface. This is to be used by drivers
10159  *	that need to tie several hardware interfaces to a single NAPI
10160  *	poll scheduler due to HW limitations.
10161  */
10162 int init_dummy_netdev(struct net_device *dev)
10163 {
10164 	/* Clear everything. Note we don't initialize spinlocks
10165 	 * are they aren't supposed to be taken by any of the
10166 	 * NAPI code and this dummy netdev is supposed to be
10167 	 * only ever used for NAPI polls
10168 	 */
10169 	memset(dev, 0, sizeof(struct net_device));
10170 
10171 	/* make sure we BUG if trying to hit standard
10172 	 * register/unregister code path
10173 	 */
10174 	dev->reg_state = NETREG_DUMMY;
10175 
10176 	/* NAPI wants this */
10177 	INIT_LIST_HEAD(&dev->napi_list);
10178 
10179 	/* a dummy interface is started by default */
10180 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10181 	set_bit(__LINK_STATE_START, &dev->state);
10182 
10183 	/* napi_busy_loop stats accounting wants this */
10184 	dev_net_set(dev, &init_net);
10185 
10186 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10187 	 * because users of this 'device' dont need to change
10188 	 * its refcount.
10189 	 */
10190 
10191 	return 0;
10192 }
10193 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10194 
10195 
10196 /**
10197  *	register_netdev	- register a network device
10198  *	@dev: device to register
10199  *
10200  *	Take a completed network device structure and add it to the kernel
10201  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10202  *	chain. 0 is returned on success. A negative errno code is returned
10203  *	on a failure to set up the device, or if the name is a duplicate.
10204  *
10205  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10206  *	and expands the device name if you passed a format string to
10207  *	alloc_netdev.
10208  */
10209 int register_netdev(struct net_device *dev)
10210 {
10211 	int err;
10212 
10213 	if (rtnl_lock_killable())
10214 		return -EINTR;
10215 	err = register_netdevice(dev);
10216 	rtnl_unlock();
10217 	return err;
10218 }
10219 EXPORT_SYMBOL(register_netdev);
10220 
10221 int netdev_refcnt_read(const struct net_device *dev)
10222 {
10223 #ifdef CONFIG_PCPU_DEV_REFCNT
10224 	int i, refcnt = 0;
10225 
10226 	for_each_possible_cpu(i)
10227 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10228 	return refcnt;
10229 #else
10230 	return refcount_read(&dev->dev_refcnt);
10231 #endif
10232 }
10233 EXPORT_SYMBOL(netdev_refcnt_read);
10234 
10235 int netdev_unregister_timeout_secs __read_mostly = 10;
10236 
10237 #define WAIT_REFS_MIN_MSECS 1
10238 #define WAIT_REFS_MAX_MSECS 250
10239 /**
10240  * netdev_wait_allrefs_any - wait until all references are gone.
10241  * @list: list of net_devices to wait on
10242  *
10243  * This is called when unregistering network devices.
10244  *
10245  * Any protocol or device that holds a reference should register
10246  * for netdevice notification, and cleanup and put back the
10247  * reference if they receive an UNREGISTER event.
10248  * We can get stuck here if buggy protocols don't correctly
10249  * call dev_put.
10250  */
10251 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10252 {
10253 	unsigned long rebroadcast_time, warning_time;
10254 	struct net_device *dev;
10255 	int wait = 0;
10256 
10257 	rebroadcast_time = warning_time = jiffies;
10258 
10259 	list_for_each_entry(dev, list, todo_list)
10260 		if (netdev_refcnt_read(dev) == 1)
10261 			return dev;
10262 
10263 	while (true) {
10264 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10265 			rtnl_lock();
10266 
10267 			/* Rebroadcast unregister notification */
10268 			list_for_each_entry(dev, list, todo_list)
10269 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10270 
10271 			__rtnl_unlock();
10272 			rcu_barrier();
10273 			rtnl_lock();
10274 
10275 			list_for_each_entry(dev, list, todo_list)
10276 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10277 					     &dev->state)) {
10278 					/* We must not have linkwatch events
10279 					 * pending on unregister. If this
10280 					 * happens, we simply run the queue
10281 					 * unscheduled, resulting in a noop
10282 					 * for this device.
10283 					 */
10284 					linkwatch_run_queue();
10285 					break;
10286 				}
10287 
10288 			__rtnl_unlock();
10289 
10290 			rebroadcast_time = jiffies;
10291 		}
10292 
10293 		if (!wait) {
10294 			rcu_barrier();
10295 			wait = WAIT_REFS_MIN_MSECS;
10296 		} else {
10297 			msleep(wait);
10298 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10299 		}
10300 
10301 		list_for_each_entry(dev, list, todo_list)
10302 			if (netdev_refcnt_read(dev) == 1)
10303 				return dev;
10304 
10305 		if (time_after(jiffies, warning_time +
10306 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10307 			list_for_each_entry(dev, list, todo_list) {
10308 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10309 					 dev->name, netdev_refcnt_read(dev));
10310 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10311 			}
10312 
10313 			warning_time = jiffies;
10314 		}
10315 	}
10316 }
10317 
10318 /* The sequence is:
10319  *
10320  *	rtnl_lock();
10321  *	...
10322  *	register_netdevice(x1);
10323  *	register_netdevice(x2);
10324  *	...
10325  *	unregister_netdevice(y1);
10326  *	unregister_netdevice(y2);
10327  *      ...
10328  *	rtnl_unlock();
10329  *	free_netdev(y1);
10330  *	free_netdev(y2);
10331  *
10332  * We are invoked by rtnl_unlock().
10333  * This allows us to deal with problems:
10334  * 1) We can delete sysfs objects which invoke hotplug
10335  *    without deadlocking with linkwatch via keventd.
10336  * 2) Since we run with the RTNL semaphore not held, we can sleep
10337  *    safely in order to wait for the netdev refcnt to drop to zero.
10338  *
10339  * We must not return until all unregister events added during
10340  * the interval the lock was held have been completed.
10341  */
10342 void netdev_run_todo(void)
10343 {
10344 	struct net_device *dev, *tmp;
10345 	struct list_head list;
10346 #ifdef CONFIG_LOCKDEP
10347 	struct list_head unlink_list;
10348 
10349 	list_replace_init(&net_unlink_list, &unlink_list);
10350 
10351 	while (!list_empty(&unlink_list)) {
10352 		struct net_device *dev = list_first_entry(&unlink_list,
10353 							  struct net_device,
10354 							  unlink_list);
10355 		list_del_init(&dev->unlink_list);
10356 		dev->nested_level = dev->lower_level - 1;
10357 	}
10358 #endif
10359 
10360 	/* Snapshot list, allow later requests */
10361 	list_replace_init(&net_todo_list, &list);
10362 
10363 	__rtnl_unlock();
10364 
10365 	/* Wait for rcu callbacks to finish before next phase */
10366 	if (!list_empty(&list))
10367 		rcu_barrier();
10368 
10369 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10370 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10371 			netdev_WARN(dev, "run_todo but not unregistering\n");
10372 			list_del(&dev->todo_list);
10373 			continue;
10374 		}
10375 
10376 		write_lock(&dev_base_lock);
10377 		dev->reg_state = NETREG_UNREGISTERED;
10378 		write_unlock(&dev_base_lock);
10379 		linkwatch_forget_dev(dev);
10380 	}
10381 
10382 	while (!list_empty(&list)) {
10383 		dev = netdev_wait_allrefs_any(&list);
10384 		list_del(&dev->todo_list);
10385 
10386 		/* paranoia */
10387 		BUG_ON(netdev_refcnt_read(dev) != 1);
10388 		BUG_ON(!list_empty(&dev->ptype_all));
10389 		BUG_ON(!list_empty(&dev->ptype_specific));
10390 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10391 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10392 
10393 		if (dev->priv_destructor)
10394 			dev->priv_destructor(dev);
10395 		if (dev->needs_free_netdev)
10396 			free_netdev(dev);
10397 
10398 		if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10399 			wake_up(&netdev_unregistering_wq);
10400 
10401 		/* Free network device */
10402 		kobject_put(&dev->dev.kobj);
10403 	}
10404 }
10405 
10406 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10407  * all the same fields in the same order as net_device_stats, with only
10408  * the type differing, but rtnl_link_stats64 may have additional fields
10409  * at the end for newer counters.
10410  */
10411 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10412 			     const struct net_device_stats *netdev_stats)
10413 {
10414 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10415 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10416 	u64 *dst = (u64 *)stats64;
10417 
10418 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10419 	for (i = 0; i < n; i++)
10420 		dst[i] = (unsigned long)atomic_long_read(&src[i]);
10421 	/* zero out counters that only exist in rtnl_link_stats64 */
10422 	memset((char *)stats64 + n * sizeof(u64), 0,
10423 	       sizeof(*stats64) - n * sizeof(u64));
10424 }
10425 EXPORT_SYMBOL(netdev_stats_to_stats64);
10426 
10427 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10428 {
10429 	struct net_device_core_stats __percpu *p;
10430 
10431 	p = alloc_percpu_gfp(struct net_device_core_stats,
10432 			     GFP_ATOMIC | __GFP_NOWARN);
10433 
10434 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10435 		free_percpu(p);
10436 
10437 	/* This READ_ONCE() pairs with the cmpxchg() above */
10438 	return READ_ONCE(dev->core_stats);
10439 }
10440 EXPORT_SYMBOL(netdev_core_stats_alloc);
10441 
10442 /**
10443  *	dev_get_stats	- get network device statistics
10444  *	@dev: device to get statistics from
10445  *	@storage: place to store stats
10446  *
10447  *	Get network statistics from device. Return @storage.
10448  *	The device driver may provide its own method by setting
10449  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10450  *	otherwise the internal statistics structure is used.
10451  */
10452 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10453 					struct rtnl_link_stats64 *storage)
10454 {
10455 	const struct net_device_ops *ops = dev->netdev_ops;
10456 	const struct net_device_core_stats __percpu *p;
10457 
10458 	if (ops->ndo_get_stats64) {
10459 		memset(storage, 0, sizeof(*storage));
10460 		ops->ndo_get_stats64(dev, storage);
10461 	} else if (ops->ndo_get_stats) {
10462 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10463 	} else {
10464 		netdev_stats_to_stats64(storage, &dev->stats);
10465 	}
10466 
10467 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10468 	p = READ_ONCE(dev->core_stats);
10469 	if (p) {
10470 		const struct net_device_core_stats *core_stats;
10471 		int i;
10472 
10473 		for_each_possible_cpu(i) {
10474 			core_stats = per_cpu_ptr(p, i);
10475 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10476 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10477 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10478 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10479 		}
10480 	}
10481 	return storage;
10482 }
10483 EXPORT_SYMBOL(dev_get_stats);
10484 
10485 /**
10486  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10487  *	@s: place to store stats
10488  *	@netstats: per-cpu network stats to read from
10489  *
10490  *	Read per-cpu network statistics and populate the related fields in @s.
10491  */
10492 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10493 			   const struct pcpu_sw_netstats __percpu *netstats)
10494 {
10495 	int cpu;
10496 
10497 	for_each_possible_cpu(cpu) {
10498 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10499 		const struct pcpu_sw_netstats *stats;
10500 		unsigned int start;
10501 
10502 		stats = per_cpu_ptr(netstats, cpu);
10503 		do {
10504 			start = u64_stats_fetch_begin(&stats->syncp);
10505 			rx_packets = u64_stats_read(&stats->rx_packets);
10506 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10507 			tx_packets = u64_stats_read(&stats->tx_packets);
10508 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10509 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10510 
10511 		s->rx_packets += rx_packets;
10512 		s->rx_bytes   += rx_bytes;
10513 		s->tx_packets += tx_packets;
10514 		s->tx_bytes   += tx_bytes;
10515 	}
10516 }
10517 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10518 
10519 /**
10520  *	dev_get_tstats64 - ndo_get_stats64 implementation
10521  *	@dev: device to get statistics from
10522  *	@s: place to store stats
10523  *
10524  *	Populate @s from dev->stats and dev->tstats. Can be used as
10525  *	ndo_get_stats64() callback.
10526  */
10527 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10528 {
10529 	netdev_stats_to_stats64(s, &dev->stats);
10530 	dev_fetch_sw_netstats(s, dev->tstats);
10531 }
10532 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10533 
10534 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10535 {
10536 	struct netdev_queue *queue = dev_ingress_queue(dev);
10537 
10538 #ifdef CONFIG_NET_CLS_ACT
10539 	if (queue)
10540 		return queue;
10541 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10542 	if (!queue)
10543 		return NULL;
10544 	netdev_init_one_queue(dev, queue, NULL);
10545 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10546 	RCU_INIT_POINTER(queue->qdisc_sleeping, &noop_qdisc);
10547 	rcu_assign_pointer(dev->ingress_queue, queue);
10548 #endif
10549 	return queue;
10550 }
10551 
10552 static const struct ethtool_ops default_ethtool_ops;
10553 
10554 void netdev_set_default_ethtool_ops(struct net_device *dev,
10555 				    const struct ethtool_ops *ops)
10556 {
10557 	if (dev->ethtool_ops == &default_ethtool_ops)
10558 		dev->ethtool_ops = ops;
10559 }
10560 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10561 
10562 /**
10563  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
10564  * @dev: netdev to enable the IRQ coalescing on
10565  *
10566  * Sets a conservative default for SW IRQ coalescing. Users can use
10567  * sysfs attributes to override the default values.
10568  */
10569 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
10570 {
10571 	WARN_ON(dev->reg_state == NETREG_REGISTERED);
10572 
10573 	dev->gro_flush_timeout = 20000;
10574 	dev->napi_defer_hard_irqs = 1;
10575 }
10576 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
10577 
10578 void netdev_freemem(struct net_device *dev)
10579 {
10580 	char *addr = (char *)dev - dev->padded;
10581 
10582 	kvfree(addr);
10583 }
10584 
10585 /**
10586  * alloc_netdev_mqs - allocate network device
10587  * @sizeof_priv: size of private data to allocate space for
10588  * @name: device name format string
10589  * @name_assign_type: origin of device name
10590  * @setup: callback to initialize device
10591  * @txqs: the number of TX subqueues to allocate
10592  * @rxqs: the number of RX subqueues to allocate
10593  *
10594  * Allocates a struct net_device with private data area for driver use
10595  * and performs basic initialization.  Also allocates subqueue structs
10596  * for each queue on the device.
10597  */
10598 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10599 		unsigned char name_assign_type,
10600 		void (*setup)(struct net_device *),
10601 		unsigned int txqs, unsigned int rxqs)
10602 {
10603 	struct net_device *dev;
10604 	unsigned int alloc_size;
10605 	struct net_device *p;
10606 
10607 	BUG_ON(strlen(name) >= sizeof(dev->name));
10608 
10609 	if (txqs < 1) {
10610 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10611 		return NULL;
10612 	}
10613 
10614 	if (rxqs < 1) {
10615 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10616 		return NULL;
10617 	}
10618 
10619 	alloc_size = sizeof(struct net_device);
10620 	if (sizeof_priv) {
10621 		/* ensure 32-byte alignment of private area */
10622 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10623 		alloc_size += sizeof_priv;
10624 	}
10625 	/* ensure 32-byte alignment of whole construct */
10626 	alloc_size += NETDEV_ALIGN - 1;
10627 
10628 	p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10629 	if (!p)
10630 		return NULL;
10631 
10632 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
10633 	dev->padded = (char *)dev - (char *)p;
10634 
10635 	ref_tracker_dir_init(&dev->refcnt_tracker, 128);
10636 #ifdef CONFIG_PCPU_DEV_REFCNT
10637 	dev->pcpu_refcnt = alloc_percpu(int);
10638 	if (!dev->pcpu_refcnt)
10639 		goto free_dev;
10640 	__dev_hold(dev);
10641 #else
10642 	refcount_set(&dev->dev_refcnt, 1);
10643 #endif
10644 
10645 	if (dev_addr_init(dev))
10646 		goto free_pcpu;
10647 
10648 	dev_mc_init(dev);
10649 	dev_uc_init(dev);
10650 
10651 	dev_net_set(dev, &init_net);
10652 
10653 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10654 	dev->gso_max_segs = GSO_MAX_SEGS;
10655 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10656 	dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
10657 	dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
10658 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10659 	dev->tso_max_segs = TSO_MAX_SEGS;
10660 	dev->upper_level = 1;
10661 	dev->lower_level = 1;
10662 #ifdef CONFIG_LOCKDEP
10663 	dev->nested_level = 0;
10664 	INIT_LIST_HEAD(&dev->unlink_list);
10665 #endif
10666 
10667 	INIT_LIST_HEAD(&dev->napi_list);
10668 	INIT_LIST_HEAD(&dev->unreg_list);
10669 	INIT_LIST_HEAD(&dev->close_list);
10670 	INIT_LIST_HEAD(&dev->link_watch_list);
10671 	INIT_LIST_HEAD(&dev->adj_list.upper);
10672 	INIT_LIST_HEAD(&dev->adj_list.lower);
10673 	INIT_LIST_HEAD(&dev->ptype_all);
10674 	INIT_LIST_HEAD(&dev->ptype_specific);
10675 	INIT_LIST_HEAD(&dev->net_notifier_list);
10676 #ifdef CONFIG_NET_SCHED
10677 	hash_init(dev->qdisc_hash);
10678 #endif
10679 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10680 	setup(dev);
10681 
10682 	if (!dev->tx_queue_len) {
10683 		dev->priv_flags |= IFF_NO_QUEUE;
10684 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10685 	}
10686 
10687 	dev->num_tx_queues = txqs;
10688 	dev->real_num_tx_queues = txqs;
10689 	if (netif_alloc_netdev_queues(dev))
10690 		goto free_all;
10691 
10692 	dev->num_rx_queues = rxqs;
10693 	dev->real_num_rx_queues = rxqs;
10694 	if (netif_alloc_rx_queues(dev))
10695 		goto free_all;
10696 
10697 	strcpy(dev->name, name);
10698 	dev->name_assign_type = name_assign_type;
10699 	dev->group = INIT_NETDEV_GROUP;
10700 	if (!dev->ethtool_ops)
10701 		dev->ethtool_ops = &default_ethtool_ops;
10702 
10703 	nf_hook_netdev_init(dev);
10704 
10705 	return dev;
10706 
10707 free_all:
10708 	free_netdev(dev);
10709 	return NULL;
10710 
10711 free_pcpu:
10712 #ifdef CONFIG_PCPU_DEV_REFCNT
10713 	free_percpu(dev->pcpu_refcnt);
10714 free_dev:
10715 #endif
10716 	netdev_freemem(dev);
10717 	return NULL;
10718 }
10719 EXPORT_SYMBOL(alloc_netdev_mqs);
10720 
10721 /**
10722  * free_netdev - free network device
10723  * @dev: device
10724  *
10725  * This function does the last stage of destroying an allocated device
10726  * interface. The reference to the device object is released. If this
10727  * is the last reference then it will be freed.Must be called in process
10728  * context.
10729  */
10730 void free_netdev(struct net_device *dev)
10731 {
10732 	struct napi_struct *p, *n;
10733 
10734 	might_sleep();
10735 
10736 	/* When called immediately after register_netdevice() failed the unwind
10737 	 * handling may still be dismantling the device. Handle that case by
10738 	 * deferring the free.
10739 	 */
10740 	if (dev->reg_state == NETREG_UNREGISTERING) {
10741 		ASSERT_RTNL();
10742 		dev->needs_free_netdev = true;
10743 		return;
10744 	}
10745 
10746 	netif_free_tx_queues(dev);
10747 	netif_free_rx_queues(dev);
10748 
10749 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10750 
10751 	/* Flush device addresses */
10752 	dev_addr_flush(dev);
10753 
10754 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10755 		netif_napi_del(p);
10756 
10757 	ref_tracker_dir_exit(&dev->refcnt_tracker);
10758 #ifdef CONFIG_PCPU_DEV_REFCNT
10759 	free_percpu(dev->pcpu_refcnt);
10760 	dev->pcpu_refcnt = NULL;
10761 #endif
10762 	free_percpu(dev->core_stats);
10763 	dev->core_stats = NULL;
10764 	free_percpu(dev->xdp_bulkq);
10765 	dev->xdp_bulkq = NULL;
10766 
10767 	/*  Compatibility with error handling in drivers */
10768 	if (dev->reg_state == NETREG_UNINITIALIZED) {
10769 		netdev_freemem(dev);
10770 		return;
10771 	}
10772 
10773 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10774 	dev->reg_state = NETREG_RELEASED;
10775 
10776 	/* will free via device release */
10777 	put_device(&dev->dev);
10778 }
10779 EXPORT_SYMBOL(free_netdev);
10780 
10781 /**
10782  *	synchronize_net -  Synchronize with packet receive processing
10783  *
10784  *	Wait for packets currently being received to be done.
10785  *	Does not block later packets from starting.
10786  */
10787 void synchronize_net(void)
10788 {
10789 	might_sleep();
10790 	if (rtnl_is_locked())
10791 		synchronize_rcu_expedited();
10792 	else
10793 		synchronize_rcu();
10794 }
10795 EXPORT_SYMBOL(synchronize_net);
10796 
10797 /**
10798  *	unregister_netdevice_queue - remove device from the kernel
10799  *	@dev: device
10800  *	@head: list
10801  *
10802  *	This function shuts down a device interface and removes it
10803  *	from the kernel tables.
10804  *	If head not NULL, device is queued to be unregistered later.
10805  *
10806  *	Callers must hold the rtnl semaphore.  You may want
10807  *	unregister_netdev() instead of this.
10808  */
10809 
10810 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10811 {
10812 	ASSERT_RTNL();
10813 
10814 	if (head) {
10815 		list_move_tail(&dev->unreg_list, head);
10816 	} else {
10817 		LIST_HEAD(single);
10818 
10819 		list_add(&dev->unreg_list, &single);
10820 		unregister_netdevice_many(&single);
10821 	}
10822 }
10823 EXPORT_SYMBOL(unregister_netdevice_queue);
10824 
10825 void unregister_netdevice_many_notify(struct list_head *head,
10826 				      u32 portid, const struct nlmsghdr *nlh)
10827 {
10828 	struct net_device *dev, *tmp;
10829 	LIST_HEAD(close_head);
10830 
10831 	BUG_ON(dev_boot_phase);
10832 	ASSERT_RTNL();
10833 
10834 	if (list_empty(head))
10835 		return;
10836 
10837 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10838 		/* Some devices call without registering
10839 		 * for initialization unwind. Remove those
10840 		 * devices and proceed with the remaining.
10841 		 */
10842 		if (dev->reg_state == NETREG_UNINITIALIZED) {
10843 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10844 				 dev->name, dev);
10845 
10846 			WARN_ON(1);
10847 			list_del(&dev->unreg_list);
10848 			continue;
10849 		}
10850 		dev->dismantle = true;
10851 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
10852 	}
10853 
10854 	/* If device is running, close it first. */
10855 	list_for_each_entry(dev, head, unreg_list)
10856 		list_add_tail(&dev->close_list, &close_head);
10857 	dev_close_many(&close_head, true);
10858 
10859 	list_for_each_entry(dev, head, unreg_list) {
10860 		/* And unlink it from device chain. */
10861 		write_lock(&dev_base_lock);
10862 		unlist_netdevice(dev, false);
10863 		dev->reg_state = NETREG_UNREGISTERING;
10864 		write_unlock(&dev_base_lock);
10865 	}
10866 	flush_all_backlogs();
10867 
10868 	synchronize_net();
10869 
10870 	list_for_each_entry(dev, head, unreg_list) {
10871 		struct sk_buff *skb = NULL;
10872 
10873 		/* Shutdown queueing discipline. */
10874 		dev_shutdown(dev);
10875 
10876 		dev_xdp_uninstall(dev);
10877 		bpf_dev_bound_netdev_unregister(dev);
10878 
10879 		netdev_offload_xstats_disable_all(dev);
10880 
10881 		/* Notify protocols, that we are about to destroy
10882 		 * this device. They should clean all the things.
10883 		 */
10884 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10885 
10886 		if (!dev->rtnl_link_ops ||
10887 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10888 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10889 						     GFP_KERNEL, NULL, 0,
10890 						     portid, nlh);
10891 
10892 		/*
10893 		 *	Flush the unicast and multicast chains
10894 		 */
10895 		dev_uc_flush(dev);
10896 		dev_mc_flush(dev);
10897 
10898 		netdev_name_node_alt_flush(dev);
10899 		netdev_name_node_free(dev->name_node);
10900 
10901 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10902 
10903 		if (dev->netdev_ops->ndo_uninit)
10904 			dev->netdev_ops->ndo_uninit(dev);
10905 
10906 		if (skb)
10907 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
10908 
10909 		/* Notifier chain MUST detach us all upper devices. */
10910 		WARN_ON(netdev_has_any_upper_dev(dev));
10911 		WARN_ON(netdev_has_any_lower_dev(dev));
10912 
10913 		/* Remove entries from kobject tree */
10914 		netdev_unregister_kobject(dev);
10915 #ifdef CONFIG_XPS
10916 		/* Remove XPS queueing entries */
10917 		netif_reset_xps_queues_gt(dev, 0);
10918 #endif
10919 	}
10920 
10921 	synchronize_net();
10922 
10923 	list_for_each_entry(dev, head, unreg_list) {
10924 		netdev_put(dev, &dev->dev_registered_tracker);
10925 		net_set_todo(dev);
10926 	}
10927 
10928 	list_del(head);
10929 }
10930 
10931 /**
10932  *	unregister_netdevice_many - unregister many devices
10933  *	@head: list of devices
10934  *
10935  *  Note: As most callers use a stack allocated list_head,
10936  *  we force a list_del() to make sure stack wont be corrupted later.
10937  */
10938 void unregister_netdevice_many(struct list_head *head)
10939 {
10940 	unregister_netdevice_many_notify(head, 0, NULL);
10941 }
10942 EXPORT_SYMBOL(unregister_netdevice_many);
10943 
10944 /**
10945  *	unregister_netdev - remove device from the kernel
10946  *	@dev: device
10947  *
10948  *	This function shuts down a device interface and removes it
10949  *	from the kernel tables.
10950  *
10951  *	This is just a wrapper for unregister_netdevice that takes
10952  *	the rtnl semaphore.  In general you want to use this and not
10953  *	unregister_netdevice.
10954  */
10955 void unregister_netdev(struct net_device *dev)
10956 {
10957 	rtnl_lock();
10958 	unregister_netdevice(dev);
10959 	rtnl_unlock();
10960 }
10961 EXPORT_SYMBOL(unregister_netdev);
10962 
10963 /**
10964  *	__dev_change_net_namespace - move device to different nethost namespace
10965  *	@dev: device
10966  *	@net: network namespace
10967  *	@pat: If not NULL name pattern to try if the current device name
10968  *	      is already taken in the destination network namespace.
10969  *	@new_ifindex: If not zero, specifies device index in the target
10970  *	              namespace.
10971  *
10972  *	This function shuts down a device interface and moves it
10973  *	to a new network namespace. On success 0 is returned, on
10974  *	a failure a netagive errno code is returned.
10975  *
10976  *	Callers must hold the rtnl semaphore.
10977  */
10978 
10979 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
10980 			       const char *pat, int new_ifindex)
10981 {
10982 	struct net *net_old = dev_net(dev);
10983 	int err, new_nsid;
10984 
10985 	ASSERT_RTNL();
10986 
10987 	/* Don't allow namespace local devices to be moved. */
10988 	err = -EINVAL;
10989 	if (dev->features & NETIF_F_NETNS_LOCAL)
10990 		goto out;
10991 
10992 	/* Ensure the device has been registrered */
10993 	if (dev->reg_state != NETREG_REGISTERED)
10994 		goto out;
10995 
10996 	/* Get out if there is nothing todo */
10997 	err = 0;
10998 	if (net_eq(net_old, net))
10999 		goto out;
11000 
11001 	/* Pick the destination device name, and ensure
11002 	 * we can use it in the destination network namespace.
11003 	 */
11004 	err = -EEXIST;
11005 	if (netdev_name_in_use(net, dev->name)) {
11006 		/* We get here if we can't use the current device name */
11007 		if (!pat)
11008 			goto out;
11009 		err = dev_get_valid_name(net, dev, pat);
11010 		if (err < 0)
11011 			goto out;
11012 	}
11013 
11014 	/* Check that new_ifindex isn't used yet. */
11015 	err = -EBUSY;
11016 	if (new_ifindex && __dev_get_by_index(net, new_ifindex))
11017 		goto out;
11018 
11019 	/*
11020 	 * And now a mini version of register_netdevice unregister_netdevice.
11021 	 */
11022 
11023 	/* If device is running close it first. */
11024 	dev_close(dev);
11025 
11026 	/* And unlink it from device chain */
11027 	unlist_netdevice(dev, true);
11028 
11029 	synchronize_net();
11030 
11031 	/* Shutdown queueing discipline. */
11032 	dev_shutdown(dev);
11033 
11034 	/* Notify protocols, that we are about to destroy
11035 	 * this device. They should clean all the things.
11036 	 *
11037 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
11038 	 * This is wanted because this way 8021q and macvlan know
11039 	 * the device is just moving and can keep their slaves up.
11040 	 */
11041 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11042 	rcu_barrier();
11043 
11044 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11045 	/* If there is an ifindex conflict assign a new one */
11046 	if (!new_ifindex) {
11047 		if (__dev_get_by_index(net, dev->ifindex))
11048 			new_ifindex = dev_new_index(net);
11049 		else
11050 			new_ifindex = dev->ifindex;
11051 	}
11052 
11053 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11054 			    new_ifindex);
11055 
11056 	/*
11057 	 *	Flush the unicast and multicast chains
11058 	 */
11059 	dev_uc_flush(dev);
11060 	dev_mc_flush(dev);
11061 
11062 	/* Send a netdev-removed uevent to the old namespace */
11063 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11064 	netdev_adjacent_del_links(dev);
11065 
11066 	/* Move per-net netdevice notifiers that are following the netdevice */
11067 	move_netdevice_notifiers_dev_net(dev, net);
11068 
11069 	/* Actually switch the network namespace */
11070 	dev_net_set(dev, net);
11071 	dev->ifindex = new_ifindex;
11072 
11073 	/* Send a netdev-add uevent to the new namespace */
11074 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11075 	netdev_adjacent_add_links(dev);
11076 
11077 	/* Fixup kobjects */
11078 	err = device_rename(&dev->dev, dev->name);
11079 	WARN_ON(err);
11080 
11081 	/* Adapt owner in case owning user namespace of target network
11082 	 * namespace is different from the original one.
11083 	 */
11084 	err = netdev_change_owner(dev, net_old, net);
11085 	WARN_ON(err);
11086 
11087 	/* Add the device back in the hashes */
11088 	list_netdevice(dev);
11089 
11090 	/* Notify protocols, that a new device appeared. */
11091 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11092 
11093 	/*
11094 	 *	Prevent userspace races by waiting until the network
11095 	 *	device is fully setup before sending notifications.
11096 	 */
11097 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11098 
11099 	synchronize_net();
11100 	err = 0;
11101 out:
11102 	return err;
11103 }
11104 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11105 
11106 static int dev_cpu_dead(unsigned int oldcpu)
11107 {
11108 	struct sk_buff **list_skb;
11109 	struct sk_buff *skb;
11110 	unsigned int cpu;
11111 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11112 
11113 	local_irq_disable();
11114 	cpu = smp_processor_id();
11115 	sd = &per_cpu(softnet_data, cpu);
11116 	oldsd = &per_cpu(softnet_data, oldcpu);
11117 
11118 	/* Find end of our completion_queue. */
11119 	list_skb = &sd->completion_queue;
11120 	while (*list_skb)
11121 		list_skb = &(*list_skb)->next;
11122 	/* Append completion queue from offline CPU. */
11123 	*list_skb = oldsd->completion_queue;
11124 	oldsd->completion_queue = NULL;
11125 
11126 	/* Append output queue from offline CPU. */
11127 	if (oldsd->output_queue) {
11128 		*sd->output_queue_tailp = oldsd->output_queue;
11129 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11130 		oldsd->output_queue = NULL;
11131 		oldsd->output_queue_tailp = &oldsd->output_queue;
11132 	}
11133 	/* Append NAPI poll list from offline CPU, with one exception :
11134 	 * process_backlog() must be called by cpu owning percpu backlog.
11135 	 * We properly handle process_queue & input_pkt_queue later.
11136 	 */
11137 	while (!list_empty(&oldsd->poll_list)) {
11138 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11139 							    struct napi_struct,
11140 							    poll_list);
11141 
11142 		list_del_init(&napi->poll_list);
11143 		if (napi->poll == process_backlog)
11144 			napi->state = 0;
11145 		else
11146 			____napi_schedule(sd, napi);
11147 	}
11148 
11149 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11150 	local_irq_enable();
11151 
11152 #ifdef CONFIG_RPS
11153 	remsd = oldsd->rps_ipi_list;
11154 	oldsd->rps_ipi_list = NULL;
11155 #endif
11156 	/* send out pending IPI's on offline CPU */
11157 	net_rps_send_ipi(remsd);
11158 
11159 	/* Process offline CPU's input_pkt_queue */
11160 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11161 		netif_rx(skb);
11162 		input_queue_head_incr(oldsd);
11163 	}
11164 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11165 		netif_rx(skb);
11166 		input_queue_head_incr(oldsd);
11167 	}
11168 
11169 	return 0;
11170 }
11171 
11172 /**
11173  *	netdev_increment_features - increment feature set by one
11174  *	@all: current feature set
11175  *	@one: new feature set
11176  *	@mask: mask feature set
11177  *
11178  *	Computes a new feature set after adding a device with feature set
11179  *	@one to the master device with current feature set @all.  Will not
11180  *	enable anything that is off in @mask. Returns the new feature set.
11181  */
11182 netdev_features_t netdev_increment_features(netdev_features_t all,
11183 	netdev_features_t one, netdev_features_t mask)
11184 {
11185 	if (mask & NETIF_F_HW_CSUM)
11186 		mask |= NETIF_F_CSUM_MASK;
11187 	mask |= NETIF_F_VLAN_CHALLENGED;
11188 
11189 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11190 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11191 
11192 	/* If one device supports hw checksumming, set for all. */
11193 	if (all & NETIF_F_HW_CSUM)
11194 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11195 
11196 	return all;
11197 }
11198 EXPORT_SYMBOL(netdev_increment_features);
11199 
11200 static struct hlist_head * __net_init netdev_create_hash(void)
11201 {
11202 	int i;
11203 	struct hlist_head *hash;
11204 
11205 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11206 	if (hash != NULL)
11207 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11208 			INIT_HLIST_HEAD(&hash[i]);
11209 
11210 	return hash;
11211 }
11212 
11213 /* Initialize per network namespace state */
11214 static int __net_init netdev_init(struct net *net)
11215 {
11216 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11217 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11218 
11219 	INIT_LIST_HEAD(&net->dev_base_head);
11220 
11221 	net->dev_name_head = netdev_create_hash();
11222 	if (net->dev_name_head == NULL)
11223 		goto err_name;
11224 
11225 	net->dev_index_head = netdev_create_hash();
11226 	if (net->dev_index_head == NULL)
11227 		goto err_idx;
11228 
11229 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11230 
11231 	return 0;
11232 
11233 err_idx:
11234 	kfree(net->dev_name_head);
11235 err_name:
11236 	return -ENOMEM;
11237 }
11238 
11239 /**
11240  *	netdev_drivername - network driver for the device
11241  *	@dev: network device
11242  *
11243  *	Determine network driver for device.
11244  */
11245 const char *netdev_drivername(const struct net_device *dev)
11246 {
11247 	const struct device_driver *driver;
11248 	const struct device *parent;
11249 	const char *empty = "";
11250 
11251 	parent = dev->dev.parent;
11252 	if (!parent)
11253 		return empty;
11254 
11255 	driver = parent->driver;
11256 	if (driver && driver->name)
11257 		return driver->name;
11258 	return empty;
11259 }
11260 
11261 static void __netdev_printk(const char *level, const struct net_device *dev,
11262 			    struct va_format *vaf)
11263 {
11264 	if (dev && dev->dev.parent) {
11265 		dev_printk_emit(level[1] - '0',
11266 				dev->dev.parent,
11267 				"%s %s %s%s: %pV",
11268 				dev_driver_string(dev->dev.parent),
11269 				dev_name(dev->dev.parent),
11270 				netdev_name(dev), netdev_reg_state(dev),
11271 				vaf);
11272 	} else if (dev) {
11273 		printk("%s%s%s: %pV",
11274 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11275 	} else {
11276 		printk("%s(NULL net_device): %pV", level, vaf);
11277 	}
11278 }
11279 
11280 void netdev_printk(const char *level, const struct net_device *dev,
11281 		   const char *format, ...)
11282 {
11283 	struct va_format vaf;
11284 	va_list args;
11285 
11286 	va_start(args, format);
11287 
11288 	vaf.fmt = format;
11289 	vaf.va = &args;
11290 
11291 	__netdev_printk(level, dev, &vaf);
11292 
11293 	va_end(args);
11294 }
11295 EXPORT_SYMBOL(netdev_printk);
11296 
11297 #define define_netdev_printk_level(func, level)			\
11298 void func(const struct net_device *dev, const char *fmt, ...)	\
11299 {								\
11300 	struct va_format vaf;					\
11301 	va_list args;						\
11302 								\
11303 	va_start(args, fmt);					\
11304 								\
11305 	vaf.fmt = fmt;						\
11306 	vaf.va = &args;						\
11307 								\
11308 	__netdev_printk(level, dev, &vaf);			\
11309 								\
11310 	va_end(args);						\
11311 }								\
11312 EXPORT_SYMBOL(func);
11313 
11314 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11315 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11316 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11317 define_netdev_printk_level(netdev_err, KERN_ERR);
11318 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11319 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11320 define_netdev_printk_level(netdev_info, KERN_INFO);
11321 
11322 static void __net_exit netdev_exit(struct net *net)
11323 {
11324 	kfree(net->dev_name_head);
11325 	kfree(net->dev_index_head);
11326 	if (net != &init_net)
11327 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11328 }
11329 
11330 static struct pernet_operations __net_initdata netdev_net_ops = {
11331 	.init = netdev_init,
11332 	.exit = netdev_exit,
11333 };
11334 
11335 static void __net_exit default_device_exit_net(struct net *net)
11336 {
11337 	struct net_device *dev, *aux;
11338 	/*
11339 	 * Push all migratable network devices back to the
11340 	 * initial network namespace
11341 	 */
11342 	ASSERT_RTNL();
11343 	for_each_netdev_safe(net, dev, aux) {
11344 		int err;
11345 		char fb_name[IFNAMSIZ];
11346 
11347 		/* Ignore unmoveable devices (i.e. loopback) */
11348 		if (dev->features & NETIF_F_NETNS_LOCAL)
11349 			continue;
11350 
11351 		/* Leave virtual devices for the generic cleanup */
11352 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11353 			continue;
11354 
11355 		/* Push remaining network devices to init_net */
11356 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11357 		if (netdev_name_in_use(&init_net, fb_name))
11358 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11359 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11360 		if (err) {
11361 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11362 				 __func__, dev->name, err);
11363 			BUG();
11364 		}
11365 	}
11366 }
11367 
11368 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11369 {
11370 	/* At exit all network devices most be removed from a network
11371 	 * namespace.  Do this in the reverse order of registration.
11372 	 * Do this across as many network namespaces as possible to
11373 	 * improve batching efficiency.
11374 	 */
11375 	struct net_device *dev;
11376 	struct net *net;
11377 	LIST_HEAD(dev_kill_list);
11378 
11379 	rtnl_lock();
11380 	list_for_each_entry(net, net_list, exit_list) {
11381 		default_device_exit_net(net);
11382 		cond_resched();
11383 	}
11384 
11385 	list_for_each_entry(net, net_list, exit_list) {
11386 		for_each_netdev_reverse(net, dev) {
11387 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11388 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11389 			else
11390 				unregister_netdevice_queue(dev, &dev_kill_list);
11391 		}
11392 	}
11393 	unregister_netdevice_many(&dev_kill_list);
11394 	rtnl_unlock();
11395 }
11396 
11397 static struct pernet_operations __net_initdata default_device_ops = {
11398 	.exit_batch = default_device_exit_batch,
11399 };
11400 
11401 /*
11402  *	Initialize the DEV module. At boot time this walks the device list and
11403  *	unhooks any devices that fail to initialise (normally hardware not
11404  *	present) and leaves us with a valid list of present and active devices.
11405  *
11406  */
11407 
11408 /*
11409  *       This is called single threaded during boot, so no need
11410  *       to take the rtnl semaphore.
11411  */
11412 static int __init net_dev_init(void)
11413 {
11414 	int i, rc = -ENOMEM;
11415 
11416 	BUG_ON(!dev_boot_phase);
11417 
11418 	if (dev_proc_init())
11419 		goto out;
11420 
11421 	if (netdev_kobject_init())
11422 		goto out;
11423 
11424 	INIT_LIST_HEAD(&ptype_all);
11425 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
11426 		INIT_LIST_HEAD(&ptype_base[i]);
11427 
11428 	if (register_pernet_subsys(&netdev_net_ops))
11429 		goto out;
11430 
11431 	/*
11432 	 *	Initialise the packet receive queues.
11433 	 */
11434 
11435 	for_each_possible_cpu(i) {
11436 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11437 		struct softnet_data *sd = &per_cpu(softnet_data, i);
11438 
11439 		INIT_WORK(flush, flush_backlog);
11440 
11441 		skb_queue_head_init(&sd->input_pkt_queue);
11442 		skb_queue_head_init(&sd->process_queue);
11443 #ifdef CONFIG_XFRM_OFFLOAD
11444 		skb_queue_head_init(&sd->xfrm_backlog);
11445 #endif
11446 		INIT_LIST_HEAD(&sd->poll_list);
11447 		sd->output_queue_tailp = &sd->output_queue;
11448 #ifdef CONFIG_RPS
11449 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11450 		sd->cpu = i;
11451 #endif
11452 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11453 		spin_lock_init(&sd->defer_lock);
11454 
11455 		init_gro_hash(&sd->backlog);
11456 		sd->backlog.poll = process_backlog;
11457 		sd->backlog.weight = weight_p;
11458 	}
11459 
11460 	dev_boot_phase = 0;
11461 
11462 	/* The loopback device is special if any other network devices
11463 	 * is present in a network namespace the loopback device must
11464 	 * be present. Since we now dynamically allocate and free the
11465 	 * loopback device ensure this invariant is maintained by
11466 	 * keeping the loopback device as the first device on the
11467 	 * list of network devices.  Ensuring the loopback devices
11468 	 * is the first device that appears and the last network device
11469 	 * that disappears.
11470 	 */
11471 	if (register_pernet_device(&loopback_net_ops))
11472 		goto out;
11473 
11474 	if (register_pernet_device(&default_device_ops))
11475 		goto out;
11476 
11477 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11478 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11479 
11480 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11481 				       NULL, dev_cpu_dead);
11482 	WARN_ON(rc < 0);
11483 	rc = 0;
11484 out:
11485 	return rc;
11486 }
11487 
11488 subsys_initcall(net_dev_init);
11489