xref: /openbmc/linux/net/core/dev.c (revision 9f7cc57f)
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_info(unsigned long val,
164 					 struct netdev_notifier_info *info);
165 static int call_netdevice_notifiers_extack(unsigned long val,
166 					   struct net_device *dev,
167 					   struct netlink_ext_ack *extack);
168 static struct napi_struct *napi_by_id(unsigned int napi_id);
169 
170 /*
171  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
172  * semaphore.
173  *
174  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
175  *
176  * Writers must hold the rtnl semaphore while they loop through the
177  * dev_base_head list, and hold dev_base_lock for writing when they do the
178  * actual updates.  This allows pure readers to access the list even
179  * while a writer is preparing to update it.
180  *
181  * To put it another way, dev_base_lock is held for writing only to
182  * protect against pure readers; the rtnl semaphore provides the
183  * protection against other writers.
184  *
185  * See, for example usages, register_netdevice() and
186  * unregister_netdevice(), which must be called with the rtnl
187  * semaphore held.
188  */
189 DEFINE_RWLOCK(dev_base_lock);
190 EXPORT_SYMBOL(dev_base_lock);
191 
192 static DEFINE_MUTEX(ifalias_mutex);
193 
194 /* protects napi_hash addition/deletion and napi_gen_id */
195 static DEFINE_SPINLOCK(napi_hash_lock);
196 
197 static unsigned int napi_gen_id = NR_CPUS;
198 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
199 
200 static DECLARE_RWSEM(devnet_rename_sem);
201 
202 static inline void dev_base_seq_inc(struct net *net)
203 {
204 	while (++net->dev_base_seq == 0)
205 		;
206 }
207 
208 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
209 {
210 	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
211 
212 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
213 }
214 
215 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
216 {
217 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
218 }
219 
220 static inline void rps_lock_irqsave(struct softnet_data *sd,
221 				    unsigned long *flags)
222 {
223 	if (IS_ENABLED(CONFIG_RPS))
224 		spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
225 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
226 		local_irq_save(*flags);
227 }
228 
229 static inline void rps_lock_irq_disable(struct softnet_data *sd)
230 {
231 	if (IS_ENABLED(CONFIG_RPS))
232 		spin_lock_irq(&sd->input_pkt_queue.lock);
233 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
234 		local_irq_disable();
235 }
236 
237 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
238 					  unsigned long *flags)
239 {
240 	if (IS_ENABLED(CONFIG_RPS))
241 		spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
242 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
243 		local_irq_restore(*flags);
244 }
245 
246 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
247 {
248 	if (IS_ENABLED(CONFIG_RPS))
249 		spin_unlock_irq(&sd->input_pkt_queue.lock);
250 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
251 		local_irq_enable();
252 }
253 
254 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
255 						       const char *name)
256 {
257 	struct netdev_name_node *name_node;
258 
259 	name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
260 	if (!name_node)
261 		return NULL;
262 	INIT_HLIST_NODE(&name_node->hlist);
263 	name_node->dev = dev;
264 	name_node->name = name;
265 	return name_node;
266 }
267 
268 static struct netdev_name_node *
269 netdev_name_node_head_alloc(struct net_device *dev)
270 {
271 	struct netdev_name_node *name_node;
272 
273 	name_node = netdev_name_node_alloc(dev, dev->name);
274 	if (!name_node)
275 		return NULL;
276 	INIT_LIST_HEAD(&name_node->list);
277 	return name_node;
278 }
279 
280 static void netdev_name_node_free(struct netdev_name_node *name_node)
281 {
282 	kfree(name_node);
283 }
284 
285 static void netdev_name_node_add(struct net *net,
286 				 struct netdev_name_node *name_node)
287 {
288 	hlist_add_head_rcu(&name_node->hlist,
289 			   dev_name_hash(net, name_node->name));
290 }
291 
292 static void netdev_name_node_del(struct netdev_name_node *name_node)
293 {
294 	hlist_del_rcu(&name_node->hlist);
295 }
296 
297 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
298 							const char *name)
299 {
300 	struct hlist_head *head = dev_name_hash(net, name);
301 	struct netdev_name_node *name_node;
302 
303 	hlist_for_each_entry(name_node, head, hlist)
304 		if (!strcmp(name_node->name, name))
305 			return name_node;
306 	return NULL;
307 }
308 
309 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
310 							    const char *name)
311 {
312 	struct hlist_head *head = dev_name_hash(net, name);
313 	struct netdev_name_node *name_node;
314 
315 	hlist_for_each_entry_rcu(name_node, head, hlist)
316 		if (!strcmp(name_node->name, name))
317 			return name_node;
318 	return NULL;
319 }
320 
321 bool netdev_name_in_use(struct net *net, const char *name)
322 {
323 	return netdev_name_node_lookup(net, name);
324 }
325 EXPORT_SYMBOL(netdev_name_in_use);
326 
327 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
328 {
329 	struct netdev_name_node *name_node;
330 	struct net *net = dev_net(dev);
331 
332 	name_node = netdev_name_node_lookup(net, name);
333 	if (name_node)
334 		return -EEXIST;
335 	name_node = netdev_name_node_alloc(dev, name);
336 	if (!name_node)
337 		return -ENOMEM;
338 	netdev_name_node_add(net, name_node);
339 	/* The node that holds dev->name acts as a head of per-device list. */
340 	list_add_tail(&name_node->list, &dev->name_node->list);
341 
342 	return 0;
343 }
344 
345 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
346 {
347 	list_del(&name_node->list);
348 	netdev_name_node_del(name_node);
349 	kfree(name_node->name);
350 	netdev_name_node_free(name_node);
351 }
352 
353 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
354 {
355 	struct netdev_name_node *name_node;
356 	struct net *net = dev_net(dev);
357 
358 	name_node = netdev_name_node_lookup(net, name);
359 	if (!name_node)
360 		return -ENOENT;
361 	/* lookup might have found our primary name or a name belonging
362 	 * to another device.
363 	 */
364 	if (name_node == dev->name_node || name_node->dev != dev)
365 		return -EINVAL;
366 
367 	__netdev_name_node_alt_destroy(name_node);
368 
369 	return 0;
370 }
371 
372 static void netdev_name_node_alt_flush(struct net_device *dev)
373 {
374 	struct netdev_name_node *name_node, *tmp;
375 
376 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
377 		__netdev_name_node_alt_destroy(name_node);
378 }
379 
380 /* Device list insertion */
381 static void list_netdevice(struct net_device *dev)
382 {
383 	struct net *net = dev_net(dev);
384 
385 	ASSERT_RTNL();
386 
387 	write_lock(&dev_base_lock);
388 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
389 	netdev_name_node_add(net, dev->name_node);
390 	hlist_add_head_rcu(&dev->index_hlist,
391 			   dev_index_hash(net, dev->ifindex));
392 	write_unlock(&dev_base_lock);
393 
394 	dev_base_seq_inc(net);
395 }
396 
397 /* Device list removal
398  * caller must respect a RCU grace period before freeing/reusing dev
399  */
400 static void unlist_netdevice(struct net_device *dev, bool lock)
401 {
402 	ASSERT_RTNL();
403 
404 	/* Unlink dev from the device chain */
405 	if (lock)
406 		write_lock(&dev_base_lock);
407 	list_del_rcu(&dev->dev_list);
408 	netdev_name_node_del(dev->name_node);
409 	hlist_del_rcu(&dev->index_hlist);
410 	if (lock)
411 		write_unlock(&dev_base_lock);
412 
413 	dev_base_seq_inc(dev_net(dev));
414 }
415 
416 /*
417  *	Our notifier list
418  */
419 
420 static RAW_NOTIFIER_HEAD(netdev_chain);
421 
422 /*
423  *	Device drivers call our routines to queue packets here. We empty the
424  *	queue in the local softnet handler.
425  */
426 
427 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
428 EXPORT_PER_CPU_SYMBOL(softnet_data);
429 
430 #ifdef CONFIG_LOCKDEP
431 /*
432  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
433  * according to dev->type
434  */
435 static const unsigned short netdev_lock_type[] = {
436 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
437 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
438 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
439 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
440 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
441 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
442 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
443 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
444 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
445 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
446 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
447 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
448 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
449 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
450 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
451 
452 static const char *const netdev_lock_name[] = {
453 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
454 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
455 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
456 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
457 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
458 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
459 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
460 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
461 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
462 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
463 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
464 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
465 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
466 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
467 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
468 
469 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
470 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
471 
472 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
473 {
474 	int i;
475 
476 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
477 		if (netdev_lock_type[i] == dev_type)
478 			return i;
479 	/* the last key is used by default */
480 	return ARRAY_SIZE(netdev_lock_type) - 1;
481 }
482 
483 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
484 						 unsigned short dev_type)
485 {
486 	int i;
487 
488 	i = netdev_lock_pos(dev_type);
489 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
490 				   netdev_lock_name[i]);
491 }
492 
493 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
494 {
495 	int i;
496 
497 	i = netdev_lock_pos(dev->type);
498 	lockdep_set_class_and_name(&dev->addr_list_lock,
499 				   &netdev_addr_lock_key[i],
500 				   netdev_lock_name[i]);
501 }
502 #else
503 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
504 						 unsigned short dev_type)
505 {
506 }
507 
508 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
509 {
510 }
511 #endif
512 
513 /*******************************************************************************
514  *
515  *		Protocol management and registration routines
516  *
517  *******************************************************************************/
518 
519 
520 /*
521  *	Add a protocol ID to the list. Now that the input handler is
522  *	smarter we can dispense with all the messy stuff that used to be
523  *	here.
524  *
525  *	BEWARE!!! Protocol handlers, mangling input packets,
526  *	MUST BE last in hash buckets and checking protocol handlers
527  *	MUST start from promiscuous ptype_all chain in net_bh.
528  *	It is true now, do not change it.
529  *	Explanation follows: if protocol handler, mangling packet, will
530  *	be the first on list, it is not able to sense, that packet
531  *	is cloned and should be copied-on-write, so that it will
532  *	change it and subsequent readers will get broken packet.
533  *							--ANK (980803)
534  */
535 
536 static inline struct list_head *ptype_head(const struct packet_type *pt)
537 {
538 	if (pt->type == htons(ETH_P_ALL))
539 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
540 	else
541 		return pt->dev ? &pt->dev->ptype_specific :
542 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
543 }
544 
545 /**
546  *	dev_add_pack - add packet handler
547  *	@pt: packet type declaration
548  *
549  *	Add a protocol handler to the networking stack. The passed &packet_type
550  *	is linked into kernel lists and may not be freed until it has been
551  *	removed from the kernel lists.
552  *
553  *	This call does not sleep therefore it can not
554  *	guarantee all CPU's that are in middle of receiving packets
555  *	will see the new packet type (until the next received packet).
556  */
557 
558 void dev_add_pack(struct packet_type *pt)
559 {
560 	struct list_head *head = ptype_head(pt);
561 
562 	spin_lock(&ptype_lock);
563 	list_add_rcu(&pt->list, head);
564 	spin_unlock(&ptype_lock);
565 }
566 EXPORT_SYMBOL(dev_add_pack);
567 
568 /**
569  *	__dev_remove_pack	 - remove packet handler
570  *	@pt: packet type declaration
571  *
572  *	Remove a protocol handler that was previously added to the kernel
573  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
574  *	from the kernel lists and can be freed or reused once this function
575  *	returns.
576  *
577  *      The packet type might still be in use by receivers
578  *	and must not be freed until after all the CPU's have gone
579  *	through a quiescent state.
580  */
581 void __dev_remove_pack(struct packet_type *pt)
582 {
583 	struct list_head *head = ptype_head(pt);
584 	struct packet_type *pt1;
585 
586 	spin_lock(&ptype_lock);
587 
588 	list_for_each_entry(pt1, head, list) {
589 		if (pt == pt1) {
590 			list_del_rcu(&pt->list);
591 			goto out;
592 		}
593 	}
594 
595 	pr_warn("dev_remove_pack: %p not found\n", pt);
596 out:
597 	spin_unlock(&ptype_lock);
598 }
599 EXPORT_SYMBOL(__dev_remove_pack);
600 
601 /**
602  *	dev_remove_pack	 - remove packet handler
603  *	@pt: packet type declaration
604  *
605  *	Remove a protocol handler that was previously added to the kernel
606  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
607  *	from the kernel lists and can be freed or reused once this function
608  *	returns.
609  *
610  *	This call sleeps to guarantee that no CPU is looking at the packet
611  *	type after return.
612  */
613 void dev_remove_pack(struct packet_type *pt)
614 {
615 	__dev_remove_pack(pt);
616 
617 	synchronize_net();
618 }
619 EXPORT_SYMBOL(dev_remove_pack);
620 
621 
622 /*******************************************************************************
623  *
624  *			    Device Interface Subroutines
625  *
626  *******************************************************************************/
627 
628 /**
629  *	dev_get_iflink	- get 'iflink' value of a interface
630  *	@dev: targeted interface
631  *
632  *	Indicates the ifindex the interface is linked to.
633  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
634  */
635 
636 int dev_get_iflink(const struct net_device *dev)
637 {
638 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
639 		return dev->netdev_ops->ndo_get_iflink(dev);
640 
641 	return dev->ifindex;
642 }
643 EXPORT_SYMBOL(dev_get_iflink);
644 
645 /**
646  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
647  *	@dev: targeted interface
648  *	@skb: The packet.
649  *
650  *	For better visibility of tunnel traffic OVS needs to retrieve
651  *	egress tunnel information for a packet. Following API allows
652  *	user to get this info.
653  */
654 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
655 {
656 	struct ip_tunnel_info *info;
657 
658 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
659 		return -EINVAL;
660 
661 	info = skb_tunnel_info_unclone(skb);
662 	if (!info)
663 		return -ENOMEM;
664 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
665 		return -EINVAL;
666 
667 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
668 }
669 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
670 
671 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
672 {
673 	int k = stack->num_paths++;
674 
675 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
676 		return NULL;
677 
678 	return &stack->path[k];
679 }
680 
681 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
682 			  struct net_device_path_stack *stack)
683 {
684 	const struct net_device *last_dev;
685 	struct net_device_path_ctx ctx = {
686 		.dev	= dev,
687 	};
688 	struct net_device_path *path;
689 	int ret = 0;
690 
691 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
692 	stack->num_paths = 0;
693 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
694 		last_dev = ctx.dev;
695 		path = dev_fwd_path(stack);
696 		if (!path)
697 			return -1;
698 
699 		memset(path, 0, sizeof(struct net_device_path));
700 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
701 		if (ret < 0)
702 			return -1;
703 
704 		if (WARN_ON_ONCE(last_dev == ctx.dev))
705 			return -1;
706 	}
707 
708 	if (!ctx.dev)
709 		return ret;
710 
711 	path = dev_fwd_path(stack);
712 	if (!path)
713 		return -1;
714 	path->type = DEV_PATH_ETHERNET;
715 	path->dev = ctx.dev;
716 
717 	return ret;
718 }
719 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
720 
721 /**
722  *	__dev_get_by_name	- find a device by its name
723  *	@net: the applicable net namespace
724  *	@name: name to find
725  *
726  *	Find an interface by name. Must be called under RTNL semaphore
727  *	or @dev_base_lock. If the name is found a pointer to the device
728  *	is returned. If the name is not found then %NULL is returned. The
729  *	reference counters are not incremented so the caller must be
730  *	careful with locks.
731  */
732 
733 struct net_device *__dev_get_by_name(struct net *net, const char *name)
734 {
735 	struct netdev_name_node *node_name;
736 
737 	node_name = netdev_name_node_lookup(net, name);
738 	return node_name ? node_name->dev : NULL;
739 }
740 EXPORT_SYMBOL(__dev_get_by_name);
741 
742 /**
743  * dev_get_by_name_rcu	- find a device by its name
744  * @net: the applicable net namespace
745  * @name: name to find
746  *
747  * Find an interface by name.
748  * If the name is found a pointer to the device is returned.
749  * If the name is not found then %NULL is returned.
750  * The reference counters are not incremented so the caller must be
751  * careful with locks. The caller must hold RCU lock.
752  */
753 
754 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
755 {
756 	struct netdev_name_node *node_name;
757 
758 	node_name = netdev_name_node_lookup_rcu(net, name);
759 	return node_name ? node_name->dev : NULL;
760 }
761 EXPORT_SYMBOL(dev_get_by_name_rcu);
762 
763 /**
764  *	dev_get_by_name		- find a device by its name
765  *	@net: the applicable net namespace
766  *	@name: name to find
767  *
768  *	Find an interface by name. This can be called from any
769  *	context and does its own locking. The returned handle has
770  *	the usage count incremented and the caller must use dev_put() to
771  *	release it when it is no longer needed. %NULL is returned if no
772  *	matching device is found.
773  */
774 
775 struct net_device *dev_get_by_name(struct net *net, const char *name)
776 {
777 	struct net_device *dev;
778 
779 	rcu_read_lock();
780 	dev = dev_get_by_name_rcu(net, name);
781 	dev_hold(dev);
782 	rcu_read_unlock();
783 	return dev;
784 }
785 EXPORT_SYMBOL(dev_get_by_name);
786 
787 /**
788  *	__dev_get_by_index - find a device by its ifindex
789  *	@net: the applicable net namespace
790  *	@ifindex: index of device
791  *
792  *	Search for an interface by index. Returns %NULL if the device
793  *	is not found or a pointer to the device. The device has not
794  *	had its reference counter increased so the caller must be careful
795  *	about locking. The caller must hold either the RTNL semaphore
796  *	or @dev_base_lock.
797  */
798 
799 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
800 {
801 	struct net_device *dev;
802 	struct hlist_head *head = dev_index_hash(net, ifindex);
803 
804 	hlist_for_each_entry(dev, head, index_hlist)
805 		if (dev->ifindex == ifindex)
806 			return dev;
807 
808 	return NULL;
809 }
810 EXPORT_SYMBOL(__dev_get_by_index);
811 
812 /**
813  *	dev_get_by_index_rcu - find a device by its ifindex
814  *	@net: the applicable net namespace
815  *	@ifindex: index of device
816  *
817  *	Search for an interface by index. Returns %NULL if the device
818  *	is not found or a pointer to the device. The device has not
819  *	had its reference counter increased so the caller must be careful
820  *	about locking. The caller must hold RCU lock.
821  */
822 
823 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
824 {
825 	struct net_device *dev;
826 	struct hlist_head *head = dev_index_hash(net, ifindex);
827 
828 	hlist_for_each_entry_rcu(dev, head, index_hlist)
829 		if (dev->ifindex == ifindex)
830 			return dev;
831 
832 	return NULL;
833 }
834 EXPORT_SYMBOL(dev_get_by_index_rcu);
835 
836 
837 /**
838  *	dev_get_by_index - find a device by its ifindex
839  *	@net: the applicable net namespace
840  *	@ifindex: index of device
841  *
842  *	Search for an interface by index. Returns NULL if the device
843  *	is not found or a pointer to the device. The device returned has
844  *	had a reference added and the pointer is safe until the user calls
845  *	dev_put to indicate they have finished with it.
846  */
847 
848 struct net_device *dev_get_by_index(struct net *net, int ifindex)
849 {
850 	struct net_device *dev;
851 
852 	rcu_read_lock();
853 	dev = dev_get_by_index_rcu(net, ifindex);
854 	dev_hold(dev);
855 	rcu_read_unlock();
856 	return dev;
857 }
858 EXPORT_SYMBOL(dev_get_by_index);
859 
860 /**
861  *	dev_get_by_napi_id - find a device by napi_id
862  *	@napi_id: ID of the NAPI struct
863  *
864  *	Search for an interface by NAPI ID. Returns %NULL if the device
865  *	is not found or a pointer to the device. The device has not had
866  *	its reference counter increased so the caller must be careful
867  *	about locking. The caller must hold RCU lock.
868  */
869 
870 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
871 {
872 	struct napi_struct *napi;
873 
874 	WARN_ON_ONCE(!rcu_read_lock_held());
875 
876 	if (napi_id < MIN_NAPI_ID)
877 		return NULL;
878 
879 	napi = napi_by_id(napi_id);
880 
881 	return napi ? napi->dev : NULL;
882 }
883 EXPORT_SYMBOL(dev_get_by_napi_id);
884 
885 /**
886  *	netdev_get_name - get a netdevice name, knowing its ifindex.
887  *	@net: network namespace
888  *	@name: a pointer to the buffer where the name will be stored.
889  *	@ifindex: the ifindex of the interface to get the name from.
890  */
891 int netdev_get_name(struct net *net, char *name, int ifindex)
892 {
893 	struct net_device *dev;
894 	int ret;
895 
896 	down_read(&devnet_rename_sem);
897 	rcu_read_lock();
898 
899 	dev = dev_get_by_index_rcu(net, ifindex);
900 	if (!dev) {
901 		ret = -ENODEV;
902 		goto out;
903 	}
904 
905 	strcpy(name, dev->name);
906 
907 	ret = 0;
908 out:
909 	rcu_read_unlock();
910 	up_read(&devnet_rename_sem);
911 	return ret;
912 }
913 
914 /**
915  *	dev_getbyhwaddr_rcu - find a device by its hardware address
916  *	@net: the applicable net namespace
917  *	@type: media type of device
918  *	@ha: hardware address
919  *
920  *	Search for an interface by MAC address. Returns NULL if the device
921  *	is not found or a pointer to the device.
922  *	The caller must hold RCU or RTNL.
923  *	The returned device has not had its ref count increased
924  *	and the caller must therefore be careful about locking
925  *
926  */
927 
928 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
929 				       const char *ha)
930 {
931 	struct net_device *dev;
932 
933 	for_each_netdev_rcu(net, dev)
934 		if (dev->type == type &&
935 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
936 			return dev;
937 
938 	return NULL;
939 }
940 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
941 
942 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
943 {
944 	struct net_device *dev, *ret = NULL;
945 
946 	rcu_read_lock();
947 	for_each_netdev_rcu(net, dev)
948 		if (dev->type == type) {
949 			dev_hold(dev);
950 			ret = dev;
951 			break;
952 		}
953 	rcu_read_unlock();
954 	return ret;
955 }
956 EXPORT_SYMBOL(dev_getfirstbyhwtype);
957 
958 /**
959  *	__dev_get_by_flags - find any device with given flags
960  *	@net: the applicable net namespace
961  *	@if_flags: IFF_* values
962  *	@mask: bitmask of bits in if_flags to check
963  *
964  *	Search for any interface with the given flags. Returns NULL if a device
965  *	is not found or a pointer to the device. Must be called inside
966  *	rtnl_lock(), and result refcount is unchanged.
967  */
968 
969 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
970 				      unsigned short mask)
971 {
972 	struct net_device *dev, *ret;
973 
974 	ASSERT_RTNL();
975 
976 	ret = NULL;
977 	for_each_netdev(net, dev) {
978 		if (((dev->flags ^ if_flags) & mask) == 0) {
979 			ret = dev;
980 			break;
981 		}
982 	}
983 	return ret;
984 }
985 EXPORT_SYMBOL(__dev_get_by_flags);
986 
987 /**
988  *	dev_valid_name - check if name is okay for network device
989  *	@name: name string
990  *
991  *	Network device names need to be valid file names to
992  *	allow sysfs to work.  We also disallow any kind of
993  *	whitespace.
994  */
995 bool dev_valid_name(const char *name)
996 {
997 	if (*name == '\0')
998 		return false;
999 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1000 		return false;
1001 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1002 		return false;
1003 
1004 	while (*name) {
1005 		if (*name == '/' || *name == ':' || isspace(*name))
1006 			return false;
1007 		name++;
1008 	}
1009 	return true;
1010 }
1011 EXPORT_SYMBOL(dev_valid_name);
1012 
1013 /**
1014  *	__dev_alloc_name - allocate a name for a device
1015  *	@net: network namespace to allocate the device name in
1016  *	@name: name format string
1017  *	@buf:  scratch buffer and result name string
1018  *
1019  *	Passed a format string - eg "lt%d" it will try and find a suitable
1020  *	id. It scans list of devices to build up a free map, then chooses
1021  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1022  *	while allocating the name and adding the device in order to avoid
1023  *	duplicates.
1024  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1025  *	Returns the number of the unit assigned or a negative errno code.
1026  */
1027 
1028 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1029 {
1030 	int i = 0;
1031 	const char *p;
1032 	const int max_netdevices = 8*PAGE_SIZE;
1033 	unsigned long *inuse;
1034 	struct net_device *d;
1035 
1036 	if (!dev_valid_name(name))
1037 		return -EINVAL;
1038 
1039 	p = strchr(name, '%');
1040 	if (p) {
1041 		/*
1042 		 * Verify the string as this thing may have come from
1043 		 * the user.  There must be either one "%d" and no other "%"
1044 		 * characters.
1045 		 */
1046 		if (p[1] != 'd' || strchr(p + 2, '%'))
1047 			return -EINVAL;
1048 
1049 		/* Use one page as a bit array of possible slots */
1050 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1051 		if (!inuse)
1052 			return -ENOMEM;
1053 
1054 		for_each_netdev(net, d) {
1055 			struct netdev_name_node *name_node;
1056 			list_for_each_entry(name_node, &d->name_node->list, list) {
1057 				if (!sscanf(name_node->name, name, &i))
1058 					continue;
1059 				if (i < 0 || i >= max_netdevices)
1060 					continue;
1061 
1062 				/*  avoid cases where sscanf is not exact inverse of printf */
1063 				snprintf(buf, IFNAMSIZ, name, i);
1064 				if (!strncmp(buf, name_node->name, IFNAMSIZ))
1065 					__set_bit(i, inuse);
1066 			}
1067 			if (!sscanf(d->name, name, &i))
1068 				continue;
1069 			if (i < 0 || i >= max_netdevices)
1070 				continue;
1071 
1072 			/*  avoid cases where sscanf is not exact inverse of printf */
1073 			snprintf(buf, IFNAMSIZ, name, i);
1074 			if (!strncmp(buf, d->name, IFNAMSIZ))
1075 				__set_bit(i, inuse);
1076 		}
1077 
1078 		i = find_first_zero_bit(inuse, max_netdevices);
1079 		free_page((unsigned long) inuse);
1080 	}
1081 
1082 	snprintf(buf, IFNAMSIZ, name, i);
1083 	if (!netdev_name_in_use(net, buf))
1084 		return i;
1085 
1086 	/* It is possible to run out of possible slots
1087 	 * when the name is long and there isn't enough space left
1088 	 * for the digits, or if all bits are used.
1089 	 */
1090 	return -ENFILE;
1091 }
1092 
1093 static int dev_alloc_name_ns(struct net *net,
1094 			     struct net_device *dev,
1095 			     const char *name)
1096 {
1097 	char buf[IFNAMSIZ];
1098 	int ret;
1099 
1100 	BUG_ON(!net);
1101 	ret = __dev_alloc_name(net, name, buf);
1102 	if (ret >= 0)
1103 		strscpy(dev->name, buf, IFNAMSIZ);
1104 	return ret;
1105 }
1106 
1107 /**
1108  *	dev_alloc_name - allocate a name for a device
1109  *	@dev: device
1110  *	@name: name format string
1111  *
1112  *	Passed a format string - eg "lt%d" it will try and find a suitable
1113  *	id. It scans list of devices to build up a free map, then chooses
1114  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1115  *	while allocating the name and adding the device in order to avoid
1116  *	duplicates.
1117  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1118  *	Returns the number of the unit assigned or a negative errno code.
1119  */
1120 
1121 int dev_alloc_name(struct net_device *dev, const char *name)
1122 {
1123 	return dev_alloc_name_ns(dev_net(dev), dev, name);
1124 }
1125 EXPORT_SYMBOL(dev_alloc_name);
1126 
1127 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1128 			      const char *name)
1129 {
1130 	BUG_ON(!net);
1131 
1132 	if (!dev_valid_name(name))
1133 		return -EINVAL;
1134 
1135 	if (strchr(name, '%'))
1136 		return dev_alloc_name_ns(net, dev, name);
1137 	else if (netdev_name_in_use(net, name))
1138 		return -EEXIST;
1139 	else if (dev->name != name)
1140 		strscpy(dev->name, name, IFNAMSIZ);
1141 
1142 	return 0;
1143 }
1144 
1145 /**
1146  *	dev_change_name - change name of a device
1147  *	@dev: device
1148  *	@newname: name (or format string) must be at least IFNAMSIZ
1149  *
1150  *	Change name of a device, can pass format strings "eth%d".
1151  *	for wildcarding.
1152  */
1153 int dev_change_name(struct net_device *dev, const char *newname)
1154 {
1155 	unsigned char old_assign_type;
1156 	char oldname[IFNAMSIZ];
1157 	int err = 0;
1158 	int ret;
1159 	struct net *net;
1160 
1161 	ASSERT_RTNL();
1162 	BUG_ON(!dev_net(dev));
1163 
1164 	net = dev_net(dev);
1165 
1166 	down_write(&devnet_rename_sem);
1167 
1168 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1169 		up_write(&devnet_rename_sem);
1170 		return 0;
1171 	}
1172 
1173 	memcpy(oldname, dev->name, IFNAMSIZ);
1174 
1175 	err = dev_get_valid_name(net, dev, newname);
1176 	if (err < 0) {
1177 		up_write(&devnet_rename_sem);
1178 		return err;
1179 	}
1180 
1181 	if (oldname[0] && !strchr(oldname, '%'))
1182 		netdev_info(dev, "renamed from %s%s\n", oldname,
1183 			    dev->flags & IFF_UP ? " (while UP)" : "");
1184 
1185 	old_assign_type = dev->name_assign_type;
1186 	dev->name_assign_type = NET_NAME_RENAMED;
1187 
1188 rollback:
1189 	ret = device_rename(&dev->dev, dev->name);
1190 	if (ret) {
1191 		memcpy(dev->name, oldname, IFNAMSIZ);
1192 		dev->name_assign_type = old_assign_type;
1193 		up_write(&devnet_rename_sem);
1194 		return ret;
1195 	}
1196 
1197 	up_write(&devnet_rename_sem);
1198 
1199 	netdev_adjacent_rename_links(dev, oldname);
1200 
1201 	write_lock(&dev_base_lock);
1202 	netdev_name_node_del(dev->name_node);
1203 	write_unlock(&dev_base_lock);
1204 
1205 	synchronize_rcu();
1206 
1207 	write_lock(&dev_base_lock);
1208 	netdev_name_node_add(net, dev->name_node);
1209 	write_unlock(&dev_base_lock);
1210 
1211 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1212 	ret = notifier_to_errno(ret);
1213 
1214 	if (ret) {
1215 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1216 		if (err >= 0) {
1217 			err = ret;
1218 			down_write(&devnet_rename_sem);
1219 			memcpy(dev->name, oldname, IFNAMSIZ);
1220 			memcpy(oldname, newname, IFNAMSIZ);
1221 			dev->name_assign_type = old_assign_type;
1222 			old_assign_type = NET_NAME_RENAMED;
1223 			goto rollback;
1224 		} else {
1225 			netdev_err(dev, "name change rollback failed: %d\n",
1226 				   ret);
1227 		}
1228 	}
1229 
1230 	return err;
1231 }
1232 
1233 /**
1234  *	dev_set_alias - change ifalias of a device
1235  *	@dev: device
1236  *	@alias: name up to IFALIASZ
1237  *	@len: limit of bytes to copy from info
1238  *
1239  *	Set ifalias for a device,
1240  */
1241 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1242 {
1243 	struct dev_ifalias *new_alias = NULL;
1244 
1245 	if (len >= IFALIASZ)
1246 		return -EINVAL;
1247 
1248 	if (len) {
1249 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1250 		if (!new_alias)
1251 			return -ENOMEM;
1252 
1253 		memcpy(new_alias->ifalias, alias, len);
1254 		new_alias->ifalias[len] = 0;
1255 	}
1256 
1257 	mutex_lock(&ifalias_mutex);
1258 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1259 					mutex_is_locked(&ifalias_mutex));
1260 	mutex_unlock(&ifalias_mutex);
1261 
1262 	if (new_alias)
1263 		kfree_rcu(new_alias, rcuhead);
1264 
1265 	return len;
1266 }
1267 EXPORT_SYMBOL(dev_set_alias);
1268 
1269 /**
1270  *	dev_get_alias - get ifalias of a device
1271  *	@dev: device
1272  *	@name: buffer to store name of ifalias
1273  *	@len: size of buffer
1274  *
1275  *	get ifalias for a device.  Caller must make sure dev cannot go
1276  *	away,  e.g. rcu read lock or own a reference count to device.
1277  */
1278 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1279 {
1280 	const struct dev_ifalias *alias;
1281 	int ret = 0;
1282 
1283 	rcu_read_lock();
1284 	alias = rcu_dereference(dev->ifalias);
1285 	if (alias)
1286 		ret = snprintf(name, len, "%s", alias->ifalias);
1287 	rcu_read_unlock();
1288 
1289 	return ret;
1290 }
1291 
1292 /**
1293  *	netdev_features_change - device changes features
1294  *	@dev: device to cause notification
1295  *
1296  *	Called to indicate a device has changed features.
1297  */
1298 void netdev_features_change(struct net_device *dev)
1299 {
1300 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1301 }
1302 EXPORT_SYMBOL(netdev_features_change);
1303 
1304 /**
1305  *	netdev_state_change - device changes state
1306  *	@dev: device to cause notification
1307  *
1308  *	Called to indicate a device has changed state. This function calls
1309  *	the notifier chains for netdev_chain and sends a NEWLINK message
1310  *	to the routing socket.
1311  */
1312 void netdev_state_change(struct net_device *dev)
1313 {
1314 	if (dev->flags & IFF_UP) {
1315 		struct netdev_notifier_change_info change_info = {
1316 			.info.dev = dev,
1317 		};
1318 
1319 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1320 					      &change_info.info);
1321 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1322 	}
1323 }
1324 EXPORT_SYMBOL(netdev_state_change);
1325 
1326 /**
1327  * __netdev_notify_peers - notify network peers about existence of @dev,
1328  * to be called when rtnl lock is already held.
1329  * @dev: network device
1330  *
1331  * Generate traffic such that interested network peers are aware of
1332  * @dev, such as by generating a gratuitous ARP. This may be used when
1333  * a device wants to inform the rest of the network about some sort of
1334  * reconfiguration such as a failover event or virtual machine
1335  * migration.
1336  */
1337 void __netdev_notify_peers(struct net_device *dev)
1338 {
1339 	ASSERT_RTNL();
1340 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1341 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1342 }
1343 EXPORT_SYMBOL(__netdev_notify_peers);
1344 
1345 /**
1346  * netdev_notify_peers - notify network peers about existence of @dev
1347  * @dev: network device
1348  *
1349  * Generate traffic such that interested network peers are aware of
1350  * @dev, such as by generating a gratuitous ARP. This may be used when
1351  * a device wants to inform the rest of the network about some sort of
1352  * reconfiguration such as a failover event or virtual machine
1353  * migration.
1354  */
1355 void netdev_notify_peers(struct net_device *dev)
1356 {
1357 	rtnl_lock();
1358 	__netdev_notify_peers(dev);
1359 	rtnl_unlock();
1360 }
1361 EXPORT_SYMBOL(netdev_notify_peers);
1362 
1363 static int napi_threaded_poll(void *data);
1364 
1365 static int napi_kthread_create(struct napi_struct *n)
1366 {
1367 	int err = 0;
1368 
1369 	/* Create and wake up the kthread once to put it in
1370 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1371 	 * warning and work with loadavg.
1372 	 */
1373 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1374 				n->dev->name, n->napi_id);
1375 	if (IS_ERR(n->thread)) {
1376 		err = PTR_ERR(n->thread);
1377 		pr_err("kthread_run failed with err %d\n", err);
1378 		n->thread = NULL;
1379 	}
1380 
1381 	return err;
1382 }
1383 
1384 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1385 {
1386 	const struct net_device_ops *ops = dev->netdev_ops;
1387 	int ret;
1388 
1389 	ASSERT_RTNL();
1390 	dev_addr_check(dev);
1391 
1392 	if (!netif_device_present(dev)) {
1393 		/* may be detached because parent is runtime-suspended */
1394 		if (dev->dev.parent)
1395 			pm_runtime_resume(dev->dev.parent);
1396 		if (!netif_device_present(dev))
1397 			return -ENODEV;
1398 	}
1399 
1400 	/* Block netpoll from trying to do any rx path servicing.
1401 	 * If we don't do this there is a chance ndo_poll_controller
1402 	 * or ndo_poll may be running while we open the device
1403 	 */
1404 	netpoll_poll_disable(dev);
1405 
1406 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1407 	ret = notifier_to_errno(ret);
1408 	if (ret)
1409 		return ret;
1410 
1411 	set_bit(__LINK_STATE_START, &dev->state);
1412 
1413 	if (ops->ndo_validate_addr)
1414 		ret = ops->ndo_validate_addr(dev);
1415 
1416 	if (!ret && ops->ndo_open)
1417 		ret = ops->ndo_open(dev);
1418 
1419 	netpoll_poll_enable(dev);
1420 
1421 	if (ret)
1422 		clear_bit(__LINK_STATE_START, &dev->state);
1423 	else {
1424 		dev->flags |= IFF_UP;
1425 		dev_set_rx_mode(dev);
1426 		dev_activate(dev);
1427 		add_device_randomness(dev->dev_addr, dev->addr_len);
1428 	}
1429 
1430 	return ret;
1431 }
1432 
1433 /**
1434  *	dev_open	- prepare an interface for use.
1435  *	@dev: device to open
1436  *	@extack: netlink extended ack
1437  *
1438  *	Takes a device from down to up state. The device's private open
1439  *	function is invoked and then the multicast lists are loaded. Finally
1440  *	the device is moved into the up state and a %NETDEV_UP message is
1441  *	sent to the netdev notifier chain.
1442  *
1443  *	Calling this function on an active interface is a nop. On a failure
1444  *	a negative errno code is returned.
1445  */
1446 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1447 {
1448 	int ret;
1449 
1450 	if (dev->flags & IFF_UP)
1451 		return 0;
1452 
1453 	ret = __dev_open(dev, extack);
1454 	if (ret < 0)
1455 		return ret;
1456 
1457 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1458 	call_netdevice_notifiers(NETDEV_UP, dev);
1459 
1460 	return ret;
1461 }
1462 EXPORT_SYMBOL(dev_open);
1463 
1464 static void __dev_close_many(struct list_head *head)
1465 {
1466 	struct net_device *dev;
1467 
1468 	ASSERT_RTNL();
1469 	might_sleep();
1470 
1471 	list_for_each_entry(dev, head, close_list) {
1472 		/* Temporarily disable netpoll until the interface is down */
1473 		netpoll_poll_disable(dev);
1474 
1475 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1476 
1477 		clear_bit(__LINK_STATE_START, &dev->state);
1478 
1479 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1480 		 * can be even on different cpu. So just clear netif_running().
1481 		 *
1482 		 * dev->stop() will invoke napi_disable() on all of it's
1483 		 * napi_struct instances on this device.
1484 		 */
1485 		smp_mb__after_atomic(); /* Commit netif_running(). */
1486 	}
1487 
1488 	dev_deactivate_many(head);
1489 
1490 	list_for_each_entry(dev, head, close_list) {
1491 		const struct net_device_ops *ops = dev->netdev_ops;
1492 
1493 		/*
1494 		 *	Call the device specific close. This cannot fail.
1495 		 *	Only if device is UP
1496 		 *
1497 		 *	We allow it to be called even after a DETACH hot-plug
1498 		 *	event.
1499 		 */
1500 		if (ops->ndo_stop)
1501 			ops->ndo_stop(dev);
1502 
1503 		dev->flags &= ~IFF_UP;
1504 		netpoll_poll_enable(dev);
1505 	}
1506 }
1507 
1508 static void __dev_close(struct net_device *dev)
1509 {
1510 	LIST_HEAD(single);
1511 
1512 	list_add(&dev->close_list, &single);
1513 	__dev_close_many(&single);
1514 	list_del(&single);
1515 }
1516 
1517 void dev_close_many(struct list_head *head, bool unlink)
1518 {
1519 	struct net_device *dev, *tmp;
1520 
1521 	/* Remove the devices that don't need to be closed */
1522 	list_for_each_entry_safe(dev, tmp, head, close_list)
1523 		if (!(dev->flags & IFF_UP))
1524 			list_del_init(&dev->close_list);
1525 
1526 	__dev_close_many(head);
1527 
1528 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1529 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1530 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1531 		if (unlink)
1532 			list_del_init(&dev->close_list);
1533 	}
1534 }
1535 EXPORT_SYMBOL(dev_close_many);
1536 
1537 /**
1538  *	dev_close - shutdown an interface.
1539  *	@dev: device to shutdown
1540  *
1541  *	This function moves an active device into down state. A
1542  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1543  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1544  *	chain.
1545  */
1546 void dev_close(struct net_device *dev)
1547 {
1548 	if (dev->flags & IFF_UP) {
1549 		LIST_HEAD(single);
1550 
1551 		list_add(&dev->close_list, &single);
1552 		dev_close_many(&single, true);
1553 		list_del(&single);
1554 	}
1555 }
1556 EXPORT_SYMBOL(dev_close);
1557 
1558 
1559 /**
1560  *	dev_disable_lro - disable Large Receive Offload on a device
1561  *	@dev: device
1562  *
1563  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1564  *	called under RTNL.  This is needed if received packets may be
1565  *	forwarded to another interface.
1566  */
1567 void dev_disable_lro(struct net_device *dev)
1568 {
1569 	struct net_device *lower_dev;
1570 	struct list_head *iter;
1571 
1572 	dev->wanted_features &= ~NETIF_F_LRO;
1573 	netdev_update_features(dev);
1574 
1575 	if (unlikely(dev->features & NETIF_F_LRO))
1576 		netdev_WARN(dev, "failed to disable LRO!\n");
1577 
1578 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1579 		dev_disable_lro(lower_dev);
1580 }
1581 EXPORT_SYMBOL(dev_disable_lro);
1582 
1583 /**
1584  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1585  *	@dev: device
1586  *
1587  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1588  *	called under RTNL.  This is needed if Generic XDP is installed on
1589  *	the device.
1590  */
1591 static void dev_disable_gro_hw(struct net_device *dev)
1592 {
1593 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1594 	netdev_update_features(dev);
1595 
1596 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1597 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1598 }
1599 
1600 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1601 {
1602 #define N(val) 						\
1603 	case NETDEV_##val:				\
1604 		return "NETDEV_" __stringify(val);
1605 	switch (cmd) {
1606 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1607 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1608 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1609 	N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1610 	N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1611 	N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1612 	N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1613 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1614 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1615 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1616 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1617 	N(XDP_FEAT_CHANGE)
1618 	}
1619 #undef N
1620 	return "UNKNOWN_NETDEV_EVENT";
1621 }
1622 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1623 
1624 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1625 				   struct net_device *dev)
1626 {
1627 	struct netdev_notifier_info info = {
1628 		.dev = dev,
1629 	};
1630 
1631 	return nb->notifier_call(nb, val, &info);
1632 }
1633 
1634 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1635 					     struct net_device *dev)
1636 {
1637 	int err;
1638 
1639 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1640 	err = notifier_to_errno(err);
1641 	if (err)
1642 		return err;
1643 
1644 	if (!(dev->flags & IFF_UP))
1645 		return 0;
1646 
1647 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1648 	return 0;
1649 }
1650 
1651 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1652 						struct net_device *dev)
1653 {
1654 	if (dev->flags & IFF_UP) {
1655 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1656 					dev);
1657 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1658 	}
1659 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1660 }
1661 
1662 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1663 						 struct net *net)
1664 {
1665 	struct net_device *dev;
1666 	int err;
1667 
1668 	for_each_netdev(net, dev) {
1669 		err = call_netdevice_register_notifiers(nb, dev);
1670 		if (err)
1671 			goto rollback;
1672 	}
1673 	return 0;
1674 
1675 rollback:
1676 	for_each_netdev_continue_reverse(net, dev)
1677 		call_netdevice_unregister_notifiers(nb, dev);
1678 	return err;
1679 }
1680 
1681 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1682 						    struct net *net)
1683 {
1684 	struct net_device *dev;
1685 
1686 	for_each_netdev(net, dev)
1687 		call_netdevice_unregister_notifiers(nb, dev);
1688 }
1689 
1690 static int dev_boot_phase = 1;
1691 
1692 /**
1693  * register_netdevice_notifier - register a network notifier block
1694  * @nb: notifier
1695  *
1696  * Register a notifier to be called when network device events occur.
1697  * The notifier passed is linked into the kernel structures and must
1698  * not be reused until it has been unregistered. A negative errno code
1699  * is returned on a failure.
1700  *
1701  * When registered all registration and up events are replayed
1702  * to the new notifier to allow device to have a race free
1703  * view of the network device list.
1704  */
1705 
1706 int register_netdevice_notifier(struct notifier_block *nb)
1707 {
1708 	struct net *net;
1709 	int err;
1710 
1711 	/* Close race with setup_net() and cleanup_net() */
1712 	down_write(&pernet_ops_rwsem);
1713 	rtnl_lock();
1714 	err = raw_notifier_chain_register(&netdev_chain, nb);
1715 	if (err)
1716 		goto unlock;
1717 	if (dev_boot_phase)
1718 		goto unlock;
1719 	for_each_net(net) {
1720 		err = call_netdevice_register_net_notifiers(nb, net);
1721 		if (err)
1722 			goto rollback;
1723 	}
1724 
1725 unlock:
1726 	rtnl_unlock();
1727 	up_write(&pernet_ops_rwsem);
1728 	return err;
1729 
1730 rollback:
1731 	for_each_net_continue_reverse(net)
1732 		call_netdevice_unregister_net_notifiers(nb, net);
1733 
1734 	raw_notifier_chain_unregister(&netdev_chain, nb);
1735 	goto unlock;
1736 }
1737 EXPORT_SYMBOL(register_netdevice_notifier);
1738 
1739 /**
1740  * unregister_netdevice_notifier - unregister a network notifier block
1741  * @nb: notifier
1742  *
1743  * Unregister a notifier previously registered by
1744  * register_netdevice_notifier(). The notifier is unlinked into the
1745  * kernel structures and may then be reused. A negative errno code
1746  * is returned on a failure.
1747  *
1748  * After unregistering unregister and down device events are synthesized
1749  * for all devices on the device list to the removed notifier to remove
1750  * the need for special case cleanup code.
1751  */
1752 
1753 int unregister_netdevice_notifier(struct notifier_block *nb)
1754 {
1755 	struct net *net;
1756 	int err;
1757 
1758 	/* Close race with setup_net() and cleanup_net() */
1759 	down_write(&pernet_ops_rwsem);
1760 	rtnl_lock();
1761 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1762 	if (err)
1763 		goto unlock;
1764 
1765 	for_each_net(net)
1766 		call_netdevice_unregister_net_notifiers(nb, net);
1767 
1768 unlock:
1769 	rtnl_unlock();
1770 	up_write(&pernet_ops_rwsem);
1771 	return err;
1772 }
1773 EXPORT_SYMBOL(unregister_netdevice_notifier);
1774 
1775 static int __register_netdevice_notifier_net(struct net *net,
1776 					     struct notifier_block *nb,
1777 					     bool ignore_call_fail)
1778 {
1779 	int err;
1780 
1781 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1782 	if (err)
1783 		return err;
1784 	if (dev_boot_phase)
1785 		return 0;
1786 
1787 	err = call_netdevice_register_net_notifiers(nb, net);
1788 	if (err && !ignore_call_fail)
1789 		goto chain_unregister;
1790 
1791 	return 0;
1792 
1793 chain_unregister:
1794 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1795 	return err;
1796 }
1797 
1798 static int __unregister_netdevice_notifier_net(struct net *net,
1799 					       struct notifier_block *nb)
1800 {
1801 	int err;
1802 
1803 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1804 	if (err)
1805 		return err;
1806 
1807 	call_netdevice_unregister_net_notifiers(nb, net);
1808 	return 0;
1809 }
1810 
1811 /**
1812  * register_netdevice_notifier_net - register a per-netns network notifier block
1813  * @net: network namespace
1814  * @nb: notifier
1815  *
1816  * Register a notifier to be called when network device events occur.
1817  * The notifier passed is linked into the kernel structures and must
1818  * not be reused until it has been unregistered. A negative errno code
1819  * is returned on a failure.
1820  *
1821  * When registered all registration and up events are replayed
1822  * to the new notifier to allow device to have a race free
1823  * view of the network device list.
1824  */
1825 
1826 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1827 {
1828 	int err;
1829 
1830 	rtnl_lock();
1831 	err = __register_netdevice_notifier_net(net, nb, false);
1832 	rtnl_unlock();
1833 	return err;
1834 }
1835 EXPORT_SYMBOL(register_netdevice_notifier_net);
1836 
1837 /**
1838  * unregister_netdevice_notifier_net - unregister a per-netns
1839  *                                     network notifier block
1840  * @net: network namespace
1841  * @nb: notifier
1842  *
1843  * Unregister a notifier previously registered by
1844  * register_netdevice_notifier_net(). The notifier is unlinked from the
1845  * kernel structures and may then be reused. A negative errno code
1846  * is returned on a failure.
1847  *
1848  * After unregistering unregister and down device events are synthesized
1849  * for all devices on the device list to the removed notifier to remove
1850  * the need for special case cleanup code.
1851  */
1852 
1853 int unregister_netdevice_notifier_net(struct net *net,
1854 				      struct notifier_block *nb)
1855 {
1856 	int err;
1857 
1858 	rtnl_lock();
1859 	err = __unregister_netdevice_notifier_net(net, nb);
1860 	rtnl_unlock();
1861 	return err;
1862 }
1863 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1864 
1865 static void __move_netdevice_notifier_net(struct net *src_net,
1866 					  struct net *dst_net,
1867 					  struct notifier_block *nb)
1868 {
1869 	__unregister_netdevice_notifier_net(src_net, nb);
1870 	__register_netdevice_notifier_net(dst_net, nb, true);
1871 }
1872 
1873 int register_netdevice_notifier_dev_net(struct net_device *dev,
1874 					struct notifier_block *nb,
1875 					struct netdev_net_notifier *nn)
1876 {
1877 	int err;
1878 
1879 	rtnl_lock();
1880 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1881 	if (!err) {
1882 		nn->nb = nb;
1883 		list_add(&nn->list, &dev->net_notifier_list);
1884 	}
1885 	rtnl_unlock();
1886 	return err;
1887 }
1888 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1889 
1890 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1891 					  struct notifier_block *nb,
1892 					  struct netdev_net_notifier *nn)
1893 {
1894 	int err;
1895 
1896 	rtnl_lock();
1897 	list_del(&nn->list);
1898 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1899 	rtnl_unlock();
1900 	return err;
1901 }
1902 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1903 
1904 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1905 					     struct net *net)
1906 {
1907 	struct netdev_net_notifier *nn;
1908 
1909 	list_for_each_entry(nn, &dev->net_notifier_list, list)
1910 		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1911 }
1912 
1913 /**
1914  *	call_netdevice_notifiers_info - call all network notifier blocks
1915  *	@val: value passed unmodified to notifier function
1916  *	@info: notifier information data
1917  *
1918  *	Call all network notifier blocks.  Parameters and return value
1919  *	are as for raw_notifier_call_chain().
1920  */
1921 
1922 static int call_netdevice_notifiers_info(unsigned long val,
1923 					 struct netdev_notifier_info *info)
1924 {
1925 	struct net *net = dev_net(info->dev);
1926 	int ret;
1927 
1928 	ASSERT_RTNL();
1929 
1930 	/* Run per-netns notifier block chain first, then run the global one.
1931 	 * Hopefully, one day, the global one is going to be removed after
1932 	 * all notifier block registrators get converted to be per-netns.
1933 	 */
1934 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1935 	if (ret & NOTIFY_STOP_MASK)
1936 		return ret;
1937 	return raw_notifier_call_chain(&netdev_chain, val, info);
1938 }
1939 
1940 /**
1941  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1942  *	                                       for and rollback on error
1943  *	@val_up: value passed unmodified to notifier function
1944  *	@val_down: value passed unmodified to the notifier function when
1945  *	           recovering from an error on @val_up
1946  *	@info: notifier information data
1947  *
1948  *	Call all per-netns network notifier blocks, but not notifier blocks on
1949  *	the global notifier chain. Parameters and return value are as for
1950  *	raw_notifier_call_chain_robust().
1951  */
1952 
1953 static int
1954 call_netdevice_notifiers_info_robust(unsigned long val_up,
1955 				     unsigned long val_down,
1956 				     struct netdev_notifier_info *info)
1957 {
1958 	struct net *net = dev_net(info->dev);
1959 
1960 	ASSERT_RTNL();
1961 
1962 	return raw_notifier_call_chain_robust(&net->netdev_chain,
1963 					      val_up, val_down, info);
1964 }
1965 
1966 static int call_netdevice_notifiers_extack(unsigned long val,
1967 					   struct net_device *dev,
1968 					   struct netlink_ext_ack *extack)
1969 {
1970 	struct netdev_notifier_info info = {
1971 		.dev = dev,
1972 		.extack = extack,
1973 	};
1974 
1975 	return call_netdevice_notifiers_info(val, &info);
1976 }
1977 
1978 /**
1979  *	call_netdevice_notifiers - call all network notifier blocks
1980  *      @val: value passed unmodified to notifier function
1981  *      @dev: net_device pointer passed unmodified to notifier function
1982  *
1983  *	Call all network notifier blocks.  Parameters and return value
1984  *	are as for raw_notifier_call_chain().
1985  */
1986 
1987 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1988 {
1989 	return call_netdevice_notifiers_extack(val, dev, NULL);
1990 }
1991 EXPORT_SYMBOL(call_netdevice_notifiers);
1992 
1993 /**
1994  *	call_netdevice_notifiers_mtu - call all network notifier blocks
1995  *	@val: value passed unmodified to notifier function
1996  *	@dev: net_device pointer passed unmodified to notifier function
1997  *	@arg: additional u32 argument passed to the notifier function
1998  *
1999  *	Call all network notifier blocks.  Parameters and return value
2000  *	are as for raw_notifier_call_chain().
2001  */
2002 static int call_netdevice_notifiers_mtu(unsigned long val,
2003 					struct net_device *dev, u32 arg)
2004 {
2005 	struct netdev_notifier_info_ext info = {
2006 		.info.dev = dev,
2007 		.ext.mtu = arg,
2008 	};
2009 
2010 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2011 
2012 	return call_netdevice_notifiers_info(val, &info.info);
2013 }
2014 
2015 #ifdef CONFIG_NET_INGRESS
2016 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2017 
2018 void net_inc_ingress_queue(void)
2019 {
2020 	static_branch_inc(&ingress_needed_key);
2021 }
2022 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2023 
2024 void net_dec_ingress_queue(void)
2025 {
2026 	static_branch_dec(&ingress_needed_key);
2027 }
2028 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2029 #endif
2030 
2031 #ifdef CONFIG_NET_EGRESS
2032 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2033 
2034 void net_inc_egress_queue(void)
2035 {
2036 	static_branch_inc(&egress_needed_key);
2037 }
2038 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2039 
2040 void net_dec_egress_queue(void)
2041 {
2042 	static_branch_dec(&egress_needed_key);
2043 }
2044 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2045 #endif
2046 
2047 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2048 EXPORT_SYMBOL(netstamp_needed_key);
2049 #ifdef CONFIG_JUMP_LABEL
2050 static atomic_t netstamp_needed_deferred;
2051 static atomic_t netstamp_wanted;
2052 static void netstamp_clear(struct work_struct *work)
2053 {
2054 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2055 	int wanted;
2056 
2057 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2058 	if (wanted > 0)
2059 		static_branch_enable(&netstamp_needed_key);
2060 	else
2061 		static_branch_disable(&netstamp_needed_key);
2062 }
2063 static DECLARE_WORK(netstamp_work, netstamp_clear);
2064 #endif
2065 
2066 void net_enable_timestamp(void)
2067 {
2068 #ifdef CONFIG_JUMP_LABEL
2069 	int wanted = atomic_read(&netstamp_wanted);
2070 
2071 	while (wanted > 0) {
2072 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2073 			return;
2074 	}
2075 	atomic_inc(&netstamp_needed_deferred);
2076 	schedule_work(&netstamp_work);
2077 #else
2078 	static_branch_inc(&netstamp_needed_key);
2079 #endif
2080 }
2081 EXPORT_SYMBOL(net_enable_timestamp);
2082 
2083 void net_disable_timestamp(void)
2084 {
2085 #ifdef CONFIG_JUMP_LABEL
2086 	int wanted = atomic_read(&netstamp_wanted);
2087 
2088 	while (wanted > 1) {
2089 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2090 			return;
2091 	}
2092 	atomic_dec(&netstamp_needed_deferred);
2093 	schedule_work(&netstamp_work);
2094 #else
2095 	static_branch_dec(&netstamp_needed_key);
2096 #endif
2097 }
2098 EXPORT_SYMBOL(net_disable_timestamp);
2099 
2100 static inline void net_timestamp_set(struct sk_buff *skb)
2101 {
2102 	skb->tstamp = 0;
2103 	skb->mono_delivery_time = 0;
2104 	if (static_branch_unlikely(&netstamp_needed_key))
2105 		skb->tstamp = ktime_get_real();
2106 }
2107 
2108 #define net_timestamp_check(COND, SKB)				\
2109 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2110 		if ((COND) && !(SKB)->tstamp)			\
2111 			(SKB)->tstamp = ktime_get_real();	\
2112 	}							\
2113 
2114 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2115 {
2116 	return __is_skb_forwardable(dev, skb, true);
2117 }
2118 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2119 
2120 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2121 			      bool check_mtu)
2122 {
2123 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2124 
2125 	if (likely(!ret)) {
2126 		skb->protocol = eth_type_trans(skb, dev);
2127 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2128 	}
2129 
2130 	return ret;
2131 }
2132 
2133 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2134 {
2135 	return __dev_forward_skb2(dev, skb, true);
2136 }
2137 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2138 
2139 /**
2140  * dev_forward_skb - loopback an skb to another netif
2141  *
2142  * @dev: destination network device
2143  * @skb: buffer to forward
2144  *
2145  * return values:
2146  *	NET_RX_SUCCESS	(no congestion)
2147  *	NET_RX_DROP     (packet was dropped, but freed)
2148  *
2149  * dev_forward_skb can be used for injecting an skb from the
2150  * start_xmit function of one device into the receive queue
2151  * of another device.
2152  *
2153  * The receiving device may be in another namespace, so
2154  * we have to clear all information in the skb that could
2155  * impact namespace isolation.
2156  */
2157 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2158 {
2159 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2160 }
2161 EXPORT_SYMBOL_GPL(dev_forward_skb);
2162 
2163 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2164 {
2165 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2166 }
2167 
2168 static inline int deliver_skb(struct sk_buff *skb,
2169 			      struct packet_type *pt_prev,
2170 			      struct net_device *orig_dev)
2171 {
2172 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2173 		return -ENOMEM;
2174 	refcount_inc(&skb->users);
2175 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2176 }
2177 
2178 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2179 					  struct packet_type **pt,
2180 					  struct net_device *orig_dev,
2181 					  __be16 type,
2182 					  struct list_head *ptype_list)
2183 {
2184 	struct packet_type *ptype, *pt_prev = *pt;
2185 
2186 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2187 		if (ptype->type != type)
2188 			continue;
2189 		if (pt_prev)
2190 			deliver_skb(skb, pt_prev, orig_dev);
2191 		pt_prev = ptype;
2192 	}
2193 	*pt = pt_prev;
2194 }
2195 
2196 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2197 {
2198 	if (!ptype->af_packet_priv || !skb->sk)
2199 		return false;
2200 
2201 	if (ptype->id_match)
2202 		return ptype->id_match(ptype, skb->sk);
2203 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2204 		return true;
2205 
2206 	return false;
2207 }
2208 
2209 /**
2210  * dev_nit_active - return true if any network interface taps are in use
2211  *
2212  * @dev: network device to check for the presence of taps
2213  */
2214 bool dev_nit_active(struct net_device *dev)
2215 {
2216 	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2217 }
2218 EXPORT_SYMBOL_GPL(dev_nit_active);
2219 
2220 /*
2221  *	Support routine. Sends outgoing frames to any network
2222  *	taps currently in use.
2223  */
2224 
2225 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2226 {
2227 	struct packet_type *ptype;
2228 	struct sk_buff *skb2 = NULL;
2229 	struct packet_type *pt_prev = NULL;
2230 	struct list_head *ptype_list = &ptype_all;
2231 
2232 	rcu_read_lock();
2233 again:
2234 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2235 		if (ptype->ignore_outgoing)
2236 			continue;
2237 
2238 		/* Never send packets back to the socket
2239 		 * they originated from - MvS (miquels@drinkel.ow.org)
2240 		 */
2241 		if (skb_loop_sk(ptype, skb))
2242 			continue;
2243 
2244 		if (pt_prev) {
2245 			deliver_skb(skb2, pt_prev, skb->dev);
2246 			pt_prev = ptype;
2247 			continue;
2248 		}
2249 
2250 		/* need to clone skb, done only once */
2251 		skb2 = skb_clone(skb, GFP_ATOMIC);
2252 		if (!skb2)
2253 			goto out_unlock;
2254 
2255 		net_timestamp_set(skb2);
2256 
2257 		/* skb->nh should be correctly
2258 		 * set by sender, so that the second statement is
2259 		 * just protection against buggy protocols.
2260 		 */
2261 		skb_reset_mac_header(skb2);
2262 
2263 		if (skb_network_header(skb2) < skb2->data ||
2264 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2265 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2266 					     ntohs(skb2->protocol),
2267 					     dev->name);
2268 			skb_reset_network_header(skb2);
2269 		}
2270 
2271 		skb2->transport_header = skb2->network_header;
2272 		skb2->pkt_type = PACKET_OUTGOING;
2273 		pt_prev = ptype;
2274 	}
2275 
2276 	if (ptype_list == &ptype_all) {
2277 		ptype_list = &dev->ptype_all;
2278 		goto again;
2279 	}
2280 out_unlock:
2281 	if (pt_prev) {
2282 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2283 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2284 		else
2285 			kfree_skb(skb2);
2286 	}
2287 	rcu_read_unlock();
2288 }
2289 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2290 
2291 /**
2292  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2293  * @dev: Network device
2294  * @txq: number of queues available
2295  *
2296  * If real_num_tx_queues is changed the tc mappings may no longer be
2297  * valid. To resolve this verify the tc mapping remains valid and if
2298  * not NULL the mapping. With no priorities mapping to this
2299  * offset/count pair it will no longer be used. In the worst case TC0
2300  * is invalid nothing can be done so disable priority mappings. If is
2301  * expected that drivers will fix this mapping if they can before
2302  * calling netif_set_real_num_tx_queues.
2303  */
2304 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2305 {
2306 	int i;
2307 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2308 
2309 	/* If TC0 is invalidated disable TC mapping */
2310 	if (tc->offset + tc->count > txq) {
2311 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2312 		dev->num_tc = 0;
2313 		return;
2314 	}
2315 
2316 	/* Invalidated prio to tc mappings set to TC0 */
2317 	for (i = 1; i < TC_BITMASK + 1; i++) {
2318 		int q = netdev_get_prio_tc_map(dev, i);
2319 
2320 		tc = &dev->tc_to_txq[q];
2321 		if (tc->offset + tc->count > txq) {
2322 			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",
2323 				    i, q);
2324 			netdev_set_prio_tc_map(dev, i, 0);
2325 		}
2326 	}
2327 }
2328 
2329 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2330 {
2331 	if (dev->num_tc) {
2332 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2333 		int i;
2334 
2335 		/* walk through the TCs and see if it falls into any of them */
2336 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2337 			if ((txq - tc->offset) < tc->count)
2338 				return i;
2339 		}
2340 
2341 		/* didn't find it, just return -1 to indicate no match */
2342 		return -1;
2343 	}
2344 
2345 	return 0;
2346 }
2347 EXPORT_SYMBOL(netdev_txq_to_tc);
2348 
2349 #ifdef CONFIG_XPS
2350 static struct static_key xps_needed __read_mostly;
2351 static struct static_key xps_rxqs_needed __read_mostly;
2352 static DEFINE_MUTEX(xps_map_mutex);
2353 #define xmap_dereference(P)		\
2354 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2355 
2356 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2357 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2358 {
2359 	struct xps_map *map = NULL;
2360 	int pos;
2361 
2362 	if (dev_maps)
2363 		map = xmap_dereference(dev_maps->attr_map[tci]);
2364 	if (!map)
2365 		return false;
2366 
2367 	for (pos = map->len; pos--;) {
2368 		if (map->queues[pos] != index)
2369 			continue;
2370 
2371 		if (map->len > 1) {
2372 			map->queues[pos] = map->queues[--map->len];
2373 			break;
2374 		}
2375 
2376 		if (old_maps)
2377 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2378 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2379 		kfree_rcu(map, rcu);
2380 		return false;
2381 	}
2382 
2383 	return true;
2384 }
2385 
2386 static bool remove_xps_queue_cpu(struct net_device *dev,
2387 				 struct xps_dev_maps *dev_maps,
2388 				 int cpu, u16 offset, u16 count)
2389 {
2390 	int num_tc = dev_maps->num_tc;
2391 	bool active = false;
2392 	int tci;
2393 
2394 	for (tci = cpu * num_tc; num_tc--; tci++) {
2395 		int i, j;
2396 
2397 		for (i = count, j = offset; i--; j++) {
2398 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2399 				break;
2400 		}
2401 
2402 		active |= i < 0;
2403 	}
2404 
2405 	return active;
2406 }
2407 
2408 static void reset_xps_maps(struct net_device *dev,
2409 			   struct xps_dev_maps *dev_maps,
2410 			   enum xps_map_type type)
2411 {
2412 	static_key_slow_dec_cpuslocked(&xps_needed);
2413 	if (type == XPS_RXQS)
2414 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2415 
2416 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2417 
2418 	kfree_rcu(dev_maps, rcu);
2419 }
2420 
2421 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2422 			   u16 offset, u16 count)
2423 {
2424 	struct xps_dev_maps *dev_maps;
2425 	bool active = false;
2426 	int i, j;
2427 
2428 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2429 	if (!dev_maps)
2430 		return;
2431 
2432 	for (j = 0; j < dev_maps->nr_ids; j++)
2433 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2434 	if (!active)
2435 		reset_xps_maps(dev, dev_maps, type);
2436 
2437 	if (type == XPS_CPUS) {
2438 		for (i = offset + (count - 1); count--; i--)
2439 			netdev_queue_numa_node_write(
2440 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2441 	}
2442 }
2443 
2444 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2445 				   u16 count)
2446 {
2447 	if (!static_key_false(&xps_needed))
2448 		return;
2449 
2450 	cpus_read_lock();
2451 	mutex_lock(&xps_map_mutex);
2452 
2453 	if (static_key_false(&xps_rxqs_needed))
2454 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2455 
2456 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2457 
2458 	mutex_unlock(&xps_map_mutex);
2459 	cpus_read_unlock();
2460 }
2461 
2462 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2463 {
2464 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2465 }
2466 
2467 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2468 				      u16 index, bool is_rxqs_map)
2469 {
2470 	struct xps_map *new_map;
2471 	int alloc_len = XPS_MIN_MAP_ALLOC;
2472 	int i, pos;
2473 
2474 	for (pos = 0; map && pos < map->len; pos++) {
2475 		if (map->queues[pos] != index)
2476 			continue;
2477 		return map;
2478 	}
2479 
2480 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2481 	if (map) {
2482 		if (pos < map->alloc_len)
2483 			return map;
2484 
2485 		alloc_len = map->alloc_len * 2;
2486 	}
2487 
2488 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2489 	 *  map
2490 	 */
2491 	if (is_rxqs_map)
2492 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2493 	else
2494 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2495 				       cpu_to_node(attr_index));
2496 	if (!new_map)
2497 		return NULL;
2498 
2499 	for (i = 0; i < pos; i++)
2500 		new_map->queues[i] = map->queues[i];
2501 	new_map->alloc_len = alloc_len;
2502 	new_map->len = pos;
2503 
2504 	return new_map;
2505 }
2506 
2507 /* Copy xps maps at a given index */
2508 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2509 			      struct xps_dev_maps *new_dev_maps, int index,
2510 			      int tc, bool skip_tc)
2511 {
2512 	int i, tci = index * dev_maps->num_tc;
2513 	struct xps_map *map;
2514 
2515 	/* copy maps belonging to foreign traffic classes */
2516 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2517 		if (i == tc && skip_tc)
2518 			continue;
2519 
2520 		/* fill in the new device map from the old device map */
2521 		map = xmap_dereference(dev_maps->attr_map[tci]);
2522 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2523 	}
2524 }
2525 
2526 /* Must be called under cpus_read_lock */
2527 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2528 			  u16 index, enum xps_map_type type)
2529 {
2530 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2531 	const unsigned long *online_mask = NULL;
2532 	bool active = false, copy = false;
2533 	int i, j, tci, numa_node_id = -2;
2534 	int maps_sz, num_tc = 1, tc = 0;
2535 	struct xps_map *map, *new_map;
2536 	unsigned int nr_ids;
2537 
2538 	WARN_ON_ONCE(index >= dev->num_tx_queues);
2539 
2540 	if (dev->num_tc) {
2541 		/* Do not allow XPS on subordinate device directly */
2542 		num_tc = dev->num_tc;
2543 		if (num_tc < 0)
2544 			return -EINVAL;
2545 
2546 		/* If queue belongs to subordinate dev use its map */
2547 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2548 
2549 		tc = netdev_txq_to_tc(dev, index);
2550 		if (tc < 0)
2551 			return -EINVAL;
2552 	}
2553 
2554 	mutex_lock(&xps_map_mutex);
2555 
2556 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2557 	if (type == XPS_RXQS) {
2558 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2559 		nr_ids = dev->num_rx_queues;
2560 	} else {
2561 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2562 		if (num_possible_cpus() > 1)
2563 			online_mask = cpumask_bits(cpu_online_mask);
2564 		nr_ids = nr_cpu_ids;
2565 	}
2566 
2567 	if (maps_sz < L1_CACHE_BYTES)
2568 		maps_sz = L1_CACHE_BYTES;
2569 
2570 	/* The old dev_maps could be larger or smaller than the one we're
2571 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2572 	 * between. We could try to be smart, but let's be safe instead and only
2573 	 * copy foreign traffic classes if the two map sizes match.
2574 	 */
2575 	if (dev_maps &&
2576 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2577 		copy = true;
2578 
2579 	/* allocate memory for queue storage */
2580 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2581 	     j < nr_ids;) {
2582 		if (!new_dev_maps) {
2583 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2584 			if (!new_dev_maps) {
2585 				mutex_unlock(&xps_map_mutex);
2586 				return -ENOMEM;
2587 			}
2588 
2589 			new_dev_maps->nr_ids = nr_ids;
2590 			new_dev_maps->num_tc = num_tc;
2591 		}
2592 
2593 		tci = j * num_tc + tc;
2594 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2595 
2596 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2597 		if (!map)
2598 			goto error;
2599 
2600 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2601 	}
2602 
2603 	if (!new_dev_maps)
2604 		goto out_no_new_maps;
2605 
2606 	if (!dev_maps) {
2607 		/* Increment static keys at most once per type */
2608 		static_key_slow_inc_cpuslocked(&xps_needed);
2609 		if (type == XPS_RXQS)
2610 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2611 	}
2612 
2613 	for (j = 0; j < nr_ids; j++) {
2614 		bool skip_tc = false;
2615 
2616 		tci = j * num_tc + tc;
2617 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2618 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2619 			/* add tx-queue to CPU/rx-queue maps */
2620 			int pos = 0;
2621 
2622 			skip_tc = true;
2623 
2624 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2625 			while ((pos < map->len) && (map->queues[pos] != index))
2626 				pos++;
2627 
2628 			if (pos == map->len)
2629 				map->queues[map->len++] = index;
2630 #ifdef CONFIG_NUMA
2631 			if (type == XPS_CPUS) {
2632 				if (numa_node_id == -2)
2633 					numa_node_id = cpu_to_node(j);
2634 				else if (numa_node_id != cpu_to_node(j))
2635 					numa_node_id = -1;
2636 			}
2637 #endif
2638 		}
2639 
2640 		if (copy)
2641 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2642 					  skip_tc);
2643 	}
2644 
2645 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2646 
2647 	/* Cleanup old maps */
2648 	if (!dev_maps)
2649 		goto out_no_old_maps;
2650 
2651 	for (j = 0; j < dev_maps->nr_ids; j++) {
2652 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2653 			map = xmap_dereference(dev_maps->attr_map[tci]);
2654 			if (!map)
2655 				continue;
2656 
2657 			if (copy) {
2658 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2659 				if (map == new_map)
2660 					continue;
2661 			}
2662 
2663 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2664 			kfree_rcu(map, rcu);
2665 		}
2666 	}
2667 
2668 	old_dev_maps = dev_maps;
2669 
2670 out_no_old_maps:
2671 	dev_maps = new_dev_maps;
2672 	active = true;
2673 
2674 out_no_new_maps:
2675 	if (type == XPS_CPUS)
2676 		/* update Tx queue numa node */
2677 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2678 					     (numa_node_id >= 0) ?
2679 					     numa_node_id : NUMA_NO_NODE);
2680 
2681 	if (!dev_maps)
2682 		goto out_no_maps;
2683 
2684 	/* removes tx-queue from unused CPUs/rx-queues */
2685 	for (j = 0; j < dev_maps->nr_ids; j++) {
2686 		tci = j * dev_maps->num_tc;
2687 
2688 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2689 			if (i == tc &&
2690 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2691 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2692 				continue;
2693 
2694 			active |= remove_xps_queue(dev_maps,
2695 						   copy ? old_dev_maps : NULL,
2696 						   tci, index);
2697 		}
2698 	}
2699 
2700 	if (old_dev_maps)
2701 		kfree_rcu(old_dev_maps, rcu);
2702 
2703 	/* free map if not active */
2704 	if (!active)
2705 		reset_xps_maps(dev, dev_maps, type);
2706 
2707 out_no_maps:
2708 	mutex_unlock(&xps_map_mutex);
2709 
2710 	return 0;
2711 error:
2712 	/* remove any maps that we added */
2713 	for (j = 0; j < nr_ids; j++) {
2714 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2715 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2716 			map = copy ?
2717 			      xmap_dereference(dev_maps->attr_map[tci]) :
2718 			      NULL;
2719 			if (new_map && new_map != map)
2720 				kfree(new_map);
2721 		}
2722 	}
2723 
2724 	mutex_unlock(&xps_map_mutex);
2725 
2726 	kfree(new_dev_maps);
2727 	return -ENOMEM;
2728 }
2729 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2730 
2731 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2732 			u16 index)
2733 {
2734 	int ret;
2735 
2736 	cpus_read_lock();
2737 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2738 	cpus_read_unlock();
2739 
2740 	return ret;
2741 }
2742 EXPORT_SYMBOL(netif_set_xps_queue);
2743 
2744 #endif
2745 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2746 {
2747 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2748 
2749 	/* Unbind any subordinate channels */
2750 	while (txq-- != &dev->_tx[0]) {
2751 		if (txq->sb_dev)
2752 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2753 	}
2754 }
2755 
2756 void netdev_reset_tc(struct net_device *dev)
2757 {
2758 #ifdef CONFIG_XPS
2759 	netif_reset_xps_queues_gt(dev, 0);
2760 #endif
2761 	netdev_unbind_all_sb_channels(dev);
2762 
2763 	/* Reset TC configuration of device */
2764 	dev->num_tc = 0;
2765 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2766 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2767 }
2768 EXPORT_SYMBOL(netdev_reset_tc);
2769 
2770 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2771 {
2772 	if (tc >= dev->num_tc)
2773 		return -EINVAL;
2774 
2775 #ifdef CONFIG_XPS
2776 	netif_reset_xps_queues(dev, offset, count);
2777 #endif
2778 	dev->tc_to_txq[tc].count = count;
2779 	dev->tc_to_txq[tc].offset = offset;
2780 	return 0;
2781 }
2782 EXPORT_SYMBOL(netdev_set_tc_queue);
2783 
2784 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2785 {
2786 	if (num_tc > TC_MAX_QUEUE)
2787 		return -EINVAL;
2788 
2789 #ifdef CONFIG_XPS
2790 	netif_reset_xps_queues_gt(dev, 0);
2791 #endif
2792 	netdev_unbind_all_sb_channels(dev);
2793 
2794 	dev->num_tc = num_tc;
2795 	return 0;
2796 }
2797 EXPORT_SYMBOL(netdev_set_num_tc);
2798 
2799 void netdev_unbind_sb_channel(struct net_device *dev,
2800 			      struct net_device *sb_dev)
2801 {
2802 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2803 
2804 #ifdef CONFIG_XPS
2805 	netif_reset_xps_queues_gt(sb_dev, 0);
2806 #endif
2807 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2808 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2809 
2810 	while (txq-- != &dev->_tx[0]) {
2811 		if (txq->sb_dev == sb_dev)
2812 			txq->sb_dev = NULL;
2813 	}
2814 }
2815 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2816 
2817 int netdev_bind_sb_channel_queue(struct net_device *dev,
2818 				 struct net_device *sb_dev,
2819 				 u8 tc, u16 count, u16 offset)
2820 {
2821 	/* Make certain the sb_dev and dev are already configured */
2822 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2823 		return -EINVAL;
2824 
2825 	/* We cannot hand out queues we don't have */
2826 	if ((offset + count) > dev->real_num_tx_queues)
2827 		return -EINVAL;
2828 
2829 	/* Record the mapping */
2830 	sb_dev->tc_to_txq[tc].count = count;
2831 	sb_dev->tc_to_txq[tc].offset = offset;
2832 
2833 	/* Provide a way for Tx queue to find the tc_to_txq map or
2834 	 * XPS map for itself.
2835 	 */
2836 	while (count--)
2837 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2838 
2839 	return 0;
2840 }
2841 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2842 
2843 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2844 {
2845 	/* Do not use a multiqueue device to represent a subordinate channel */
2846 	if (netif_is_multiqueue(dev))
2847 		return -ENODEV;
2848 
2849 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2850 	 * Channel 0 is meant to be "native" mode and used only to represent
2851 	 * the main root device. We allow writing 0 to reset the device back
2852 	 * to normal mode after being used as a subordinate channel.
2853 	 */
2854 	if (channel > S16_MAX)
2855 		return -EINVAL;
2856 
2857 	dev->num_tc = -channel;
2858 
2859 	return 0;
2860 }
2861 EXPORT_SYMBOL(netdev_set_sb_channel);
2862 
2863 /*
2864  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2865  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2866  */
2867 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2868 {
2869 	bool disabling;
2870 	int rc;
2871 
2872 	disabling = txq < dev->real_num_tx_queues;
2873 
2874 	if (txq < 1 || txq > dev->num_tx_queues)
2875 		return -EINVAL;
2876 
2877 	if (dev->reg_state == NETREG_REGISTERED ||
2878 	    dev->reg_state == NETREG_UNREGISTERING) {
2879 		ASSERT_RTNL();
2880 
2881 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2882 						  txq);
2883 		if (rc)
2884 			return rc;
2885 
2886 		if (dev->num_tc)
2887 			netif_setup_tc(dev, txq);
2888 
2889 		dev_qdisc_change_real_num_tx(dev, txq);
2890 
2891 		dev->real_num_tx_queues = txq;
2892 
2893 		if (disabling) {
2894 			synchronize_net();
2895 			qdisc_reset_all_tx_gt(dev, txq);
2896 #ifdef CONFIG_XPS
2897 			netif_reset_xps_queues_gt(dev, txq);
2898 #endif
2899 		}
2900 	} else {
2901 		dev->real_num_tx_queues = txq;
2902 	}
2903 
2904 	return 0;
2905 }
2906 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2907 
2908 #ifdef CONFIG_SYSFS
2909 /**
2910  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2911  *	@dev: Network device
2912  *	@rxq: Actual number of RX queues
2913  *
2914  *	This must be called either with the rtnl_lock held or before
2915  *	registration of the net device.  Returns 0 on success, or a
2916  *	negative error code.  If called before registration, it always
2917  *	succeeds.
2918  */
2919 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2920 {
2921 	int rc;
2922 
2923 	if (rxq < 1 || rxq > dev->num_rx_queues)
2924 		return -EINVAL;
2925 
2926 	if (dev->reg_state == NETREG_REGISTERED) {
2927 		ASSERT_RTNL();
2928 
2929 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2930 						  rxq);
2931 		if (rc)
2932 			return rc;
2933 	}
2934 
2935 	dev->real_num_rx_queues = rxq;
2936 	return 0;
2937 }
2938 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2939 #endif
2940 
2941 /**
2942  *	netif_set_real_num_queues - set actual number of RX and TX queues used
2943  *	@dev: Network device
2944  *	@txq: Actual number of TX queues
2945  *	@rxq: Actual number of RX queues
2946  *
2947  *	Set the real number of both TX and RX queues.
2948  *	Does nothing if the number of queues is already correct.
2949  */
2950 int netif_set_real_num_queues(struct net_device *dev,
2951 			      unsigned int txq, unsigned int rxq)
2952 {
2953 	unsigned int old_rxq = dev->real_num_rx_queues;
2954 	int err;
2955 
2956 	if (txq < 1 || txq > dev->num_tx_queues ||
2957 	    rxq < 1 || rxq > dev->num_rx_queues)
2958 		return -EINVAL;
2959 
2960 	/* Start from increases, so the error path only does decreases -
2961 	 * decreases can't fail.
2962 	 */
2963 	if (rxq > dev->real_num_rx_queues) {
2964 		err = netif_set_real_num_rx_queues(dev, rxq);
2965 		if (err)
2966 			return err;
2967 	}
2968 	if (txq > dev->real_num_tx_queues) {
2969 		err = netif_set_real_num_tx_queues(dev, txq);
2970 		if (err)
2971 			goto undo_rx;
2972 	}
2973 	if (rxq < dev->real_num_rx_queues)
2974 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
2975 	if (txq < dev->real_num_tx_queues)
2976 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
2977 
2978 	return 0;
2979 undo_rx:
2980 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
2981 	return err;
2982 }
2983 EXPORT_SYMBOL(netif_set_real_num_queues);
2984 
2985 /**
2986  * netif_set_tso_max_size() - set the max size of TSO frames supported
2987  * @dev:	netdev to update
2988  * @size:	max skb->len of a TSO frame
2989  *
2990  * Set the limit on the size of TSO super-frames the device can handle.
2991  * Unless explicitly set the stack will assume the value of
2992  * %GSO_LEGACY_MAX_SIZE.
2993  */
2994 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
2995 {
2996 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
2997 	if (size < READ_ONCE(dev->gso_max_size))
2998 		netif_set_gso_max_size(dev, size);
2999 	if (size < READ_ONCE(dev->gso_ipv4_max_size))
3000 		netif_set_gso_ipv4_max_size(dev, size);
3001 }
3002 EXPORT_SYMBOL(netif_set_tso_max_size);
3003 
3004 /**
3005  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3006  * @dev:	netdev to update
3007  * @segs:	max number of TCP segments
3008  *
3009  * Set the limit on the number of TCP segments the device can generate from
3010  * a single TSO super-frame.
3011  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3012  */
3013 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3014 {
3015 	dev->tso_max_segs = segs;
3016 	if (segs < READ_ONCE(dev->gso_max_segs))
3017 		netif_set_gso_max_segs(dev, segs);
3018 }
3019 EXPORT_SYMBOL(netif_set_tso_max_segs);
3020 
3021 /**
3022  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3023  * @to:		netdev to update
3024  * @from:	netdev from which to copy the limits
3025  */
3026 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3027 {
3028 	netif_set_tso_max_size(to, from->tso_max_size);
3029 	netif_set_tso_max_segs(to, from->tso_max_segs);
3030 }
3031 EXPORT_SYMBOL(netif_inherit_tso_max);
3032 
3033 /**
3034  * netif_get_num_default_rss_queues - default number of RSS queues
3035  *
3036  * Default value is the number of physical cores if there are only 1 or 2, or
3037  * divided by 2 if there are more.
3038  */
3039 int netif_get_num_default_rss_queues(void)
3040 {
3041 	cpumask_var_t cpus;
3042 	int cpu, count = 0;
3043 
3044 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3045 		return 1;
3046 
3047 	cpumask_copy(cpus, cpu_online_mask);
3048 	for_each_cpu(cpu, cpus) {
3049 		++count;
3050 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3051 	}
3052 	free_cpumask_var(cpus);
3053 
3054 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3055 }
3056 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3057 
3058 static void __netif_reschedule(struct Qdisc *q)
3059 {
3060 	struct softnet_data *sd;
3061 	unsigned long flags;
3062 
3063 	local_irq_save(flags);
3064 	sd = this_cpu_ptr(&softnet_data);
3065 	q->next_sched = NULL;
3066 	*sd->output_queue_tailp = q;
3067 	sd->output_queue_tailp = &q->next_sched;
3068 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3069 	local_irq_restore(flags);
3070 }
3071 
3072 void __netif_schedule(struct Qdisc *q)
3073 {
3074 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3075 		__netif_reschedule(q);
3076 }
3077 EXPORT_SYMBOL(__netif_schedule);
3078 
3079 struct dev_kfree_skb_cb {
3080 	enum skb_drop_reason reason;
3081 };
3082 
3083 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3084 {
3085 	return (struct dev_kfree_skb_cb *)skb->cb;
3086 }
3087 
3088 void netif_schedule_queue(struct netdev_queue *txq)
3089 {
3090 	rcu_read_lock();
3091 	if (!netif_xmit_stopped(txq)) {
3092 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3093 
3094 		__netif_schedule(q);
3095 	}
3096 	rcu_read_unlock();
3097 }
3098 EXPORT_SYMBOL(netif_schedule_queue);
3099 
3100 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3101 {
3102 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3103 		struct Qdisc *q;
3104 
3105 		rcu_read_lock();
3106 		q = rcu_dereference(dev_queue->qdisc);
3107 		__netif_schedule(q);
3108 		rcu_read_unlock();
3109 	}
3110 }
3111 EXPORT_SYMBOL(netif_tx_wake_queue);
3112 
3113 void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3114 {
3115 	unsigned long flags;
3116 
3117 	if (unlikely(!skb))
3118 		return;
3119 
3120 	if (likely(refcount_read(&skb->users) == 1)) {
3121 		smp_rmb();
3122 		refcount_set(&skb->users, 0);
3123 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3124 		return;
3125 	}
3126 	get_kfree_skb_cb(skb)->reason = reason;
3127 	local_irq_save(flags);
3128 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3129 	__this_cpu_write(softnet_data.completion_queue, skb);
3130 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3131 	local_irq_restore(flags);
3132 }
3133 EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
3134 
3135 void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3136 {
3137 	if (in_hardirq() || irqs_disabled())
3138 		dev_kfree_skb_irq_reason(skb, reason);
3139 	else
3140 		kfree_skb_reason(skb, reason);
3141 }
3142 EXPORT_SYMBOL(dev_kfree_skb_any_reason);
3143 
3144 
3145 /**
3146  * netif_device_detach - mark device as removed
3147  * @dev: network device
3148  *
3149  * Mark device as removed from system and therefore no longer available.
3150  */
3151 void netif_device_detach(struct net_device *dev)
3152 {
3153 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3154 	    netif_running(dev)) {
3155 		netif_tx_stop_all_queues(dev);
3156 	}
3157 }
3158 EXPORT_SYMBOL(netif_device_detach);
3159 
3160 /**
3161  * netif_device_attach - mark device as attached
3162  * @dev: network device
3163  *
3164  * Mark device as attached from system and restart if needed.
3165  */
3166 void netif_device_attach(struct net_device *dev)
3167 {
3168 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3169 	    netif_running(dev)) {
3170 		netif_tx_wake_all_queues(dev);
3171 		__netdev_watchdog_up(dev);
3172 	}
3173 }
3174 EXPORT_SYMBOL(netif_device_attach);
3175 
3176 /*
3177  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3178  * to be used as a distribution range.
3179  */
3180 static u16 skb_tx_hash(const struct net_device *dev,
3181 		       const struct net_device *sb_dev,
3182 		       struct sk_buff *skb)
3183 {
3184 	u32 hash;
3185 	u16 qoffset = 0;
3186 	u16 qcount = dev->real_num_tx_queues;
3187 
3188 	if (dev->num_tc) {
3189 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3190 
3191 		qoffset = sb_dev->tc_to_txq[tc].offset;
3192 		qcount = sb_dev->tc_to_txq[tc].count;
3193 		if (unlikely(!qcount)) {
3194 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3195 					     sb_dev->name, qoffset, tc);
3196 			qoffset = 0;
3197 			qcount = dev->real_num_tx_queues;
3198 		}
3199 	}
3200 
3201 	if (skb_rx_queue_recorded(skb)) {
3202 		hash = skb_get_rx_queue(skb);
3203 		if (hash >= qoffset)
3204 			hash -= qoffset;
3205 		while (unlikely(hash >= qcount))
3206 			hash -= qcount;
3207 		return hash + qoffset;
3208 	}
3209 
3210 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3211 }
3212 
3213 static void skb_warn_bad_offload(const struct sk_buff *skb)
3214 {
3215 	static const netdev_features_t null_features;
3216 	struct net_device *dev = skb->dev;
3217 	const char *name = "";
3218 
3219 	if (!net_ratelimit())
3220 		return;
3221 
3222 	if (dev) {
3223 		if (dev->dev.parent)
3224 			name = dev_driver_string(dev->dev.parent);
3225 		else
3226 			name = netdev_name(dev);
3227 	}
3228 	skb_dump(KERN_WARNING, skb, false);
3229 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3230 	     name, dev ? &dev->features : &null_features,
3231 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3232 }
3233 
3234 /*
3235  * Invalidate hardware checksum when packet is to be mangled, and
3236  * complete checksum manually on outgoing path.
3237  */
3238 int skb_checksum_help(struct sk_buff *skb)
3239 {
3240 	__wsum csum;
3241 	int ret = 0, offset;
3242 
3243 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3244 		goto out_set_summed;
3245 
3246 	if (unlikely(skb_is_gso(skb))) {
3247 		skb_warn_bad_offload(skb);
3248 		return -EINVAL;
3249 	}
3250 
3251 	/* Before computing a checksum, we should make sure no frag could
3252 	 * be modified by an external entity : checksum could be wrong.
3253 	 */
3254 	if (skb_has_shared_frag(skb)) {
3255 		ret = __skb_linearize(skb);
3256 		if (ret)
3257 			goto out;
3258 	}
3259 
3260 	offset = skb_checksum_start_offset(skb);
3261 	ret = -EINVAL;
3262 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3263 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3264 		goto out;
3265 	}
3266 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3267 
3268 	offset += skb->csum_offset;
3269 	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
3270 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3271 		goto out;
3272 	}
3273 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3274 	if (ret)
3275 		goto out;
3276 
3277 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3278 out_set_summed:
3279 	skb->ip_summed = CHECKSUM_NONE;
3280 out:
3281 	return ret;
3282 }
3283 EXPORT_SYMBOL(skb_checksum_help);
3284 
3285 int skb_crc32c_csum_help(struct sk_buff *skb)
3286 {
3287 	__le32 crc32c_csum;
3288 	int ret = 0, offset, start;
3289 
3290 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3291 		goto out;
3292 
3293 	if (unlikely(skb_is_gso(skb)))
3294 		goto out;
3295 
3296 	/* Before computing a checksum, we should make sure no frag could
3297 	 * be modified by an external entity : checksum could be wrong.
3298 	 */
3299 	if (unlikely(skb_has_shared_frag(skb))) {
3300 		ret = __skb_linearize(skb);
3301 		if (ret)
3302 			goto out;
3303 	}
3304 	start = skb_checksum_start_offset(skb);
3305 	offset = start + offsetof(struct sctphdr, checksum);
3306 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3307 		ret = -EINVAL;
3308 		goto out;
3309 	}
3310 
3311 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3312 	if (ret)
3313 		goto out;
3314 
3315 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3316 						  skb->len - start, ~(__u32)0,
3317 						  crc32c_csum_stub));
3318 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3319 	skb->ip_summed = CHECKSUM_NONE;
3320 	skb->csum_not_inet = 0;
3321 out:
3322 	return ret;
3323 }
3324 
3325 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3326 {
3327 	__be16 type = skb->protocol;
3328 
3329 	/* Tunnel gso handlers can set protocol to ethernet. */
3330 	if (type == htons(ETH_P_TEB)) {
3331 		struct ethhdr *eth;
3332 
3333 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3334 			return 0;
3335 
3336 		eth = (struct ethhdr *)skb->data;
3337 		type = eth->h_proto;
3338 	}
3339 
3340 	return __vlan_get_protocol(skb, type, depth);
3341 }
3342 
3343 /* openvswitch calls this on rx path, so we need a different check.
3344  */
3345 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3346 {
3347 	if (tx_path)
3348 		return skb->ip_summed != CHECKSUM_PARTIAL &&
3349 		       skb->ip_summed != CHECKSUM_UNNECESSARY;
3350 
3351 	return skb->ip_summed == CHECKSUM_NONE;
3352 }
3353 
3354 /**
3355  *	__skb_gso_segment - Perform segmentation on skb.
3356  *	@skb: buffer to segment
3357  *	@features: features for the output path (see dev->features)
3358  *	@tx_path: whether it is called in TX path
3359  *
3360  *	This function segments the given skb and returns a list of segments.
3361  *
3362  *	It may return NULL if the skb requires no segmentation.  This is
3363  *	only possible when GSO is used for verifying header integrity.
3364  *
3365  *	Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3366  */
3367 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3368 				  netdev_features_t features, bool tx_path)
3369 {
3370 	struct sk_buff *segs;
3371 
3372 	if (unlikely(skb_needs_check(skb, tx_path))) {
3373 		int err;
3374 
3375 		/* We're going to init ->check field in TCP or UDP header */
3376 		err = skb_cow_head(skb, 0);
3377 		if (err < 0)
3378 			return ERR_PTR(err);
3379 	}
3380 
3381 	/* Only report GSO partial support if it will enable us to
3382 	 * support segmentation on this frame without needing additional
3383 	 * work.
3384 	 */
3385 	if (features & NETIF_F_GSO_PARTIAL) {
3386 		netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3387 		struct net_device *dev = skb->dev;
3388 
3389 		partial_features |= dev->features & dev->gso_partial_features;
3390 		if (!skb_gso_ok(skb, features | partial_features))
3391 			features &= ~NETIF_F_GSO_PARTIAL;
3392 	}
3393 
3394 	BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3395 		     sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3396 
3397 	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3398 	SKB_GSO_CB(skb)->encap_level = 0;
3399 
3400 	skb_reset_mac_header(skb);
3401 	skb_reset_mac_len(skb);
3402 
3403 	segs = skb_mac_gso_segment(skb, features);
3404 
3405 	if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3406 		skb_warn_bad_offload(skb);
3407 
3408 	return segs;
3409 }
3410 EXPORT_SYMBOL(__skb_gso_segment);
3411 
3412 /* Take action when hardware reception checksum errors are detected. */
3413 #ifdef CONFIG_BUG
3414 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3415 {
3416 	netdev_err(dev, "hw csum failure\n");
3417 	skb_dump(KERN_ERR, skb, true);
3418 	dump_stack();
3419 }
3420 
3421 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3422 {
3423 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3424 }
3425 EXPORT_SYMBOL(netdev_rx_csum_fault);
3426 #endif
3427 
3428 /* XXX: check that highmem exists at all on the given machine. */
3429 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3430 {
3431 #ifdef CONFIG_HIGHMEM
3432 	int i;
3433 
3434 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3435 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3436 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3437 
3438 			if (PageHighMem(skb_frag_page(frag)))
3439 				return 1;
3440 		}
3441 	}
3442 #endif
3443 	return 0;
3444 }
3445 
3446 /* If MPLS offload request, verify we are testing hardware MPLS features
3447  * instead of standard features for the netdev.
3448  */
3449 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3450 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3451 					   netdev_features_t features,
3452 					   __be16 type)
3453 {
3454 	if (eth_p_mpls(type))
3455 		features &= skb->dev->mpls_features;
3456 
3457 	return features;
3458 }
3459 #else
3460 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3461 					   netdev_features_t features,
3462 					   __be16 type)
3463 {
3464 	return features;
3465 }
3466 #endif
3467 
3468 static netdev_features_t harmonize_features(struct sk_buff *skb,
3469 	netdev_features_t features)
3470 {
3471 	__be16 type;
3472 
3473 	type = skb_network_protocol(skb, NULL);
3474 	features = net_mpls_features(skb, features, type);
3475 
3476 	if (skb->ip_summed != CHECKSUM_NONE &&
3477 	    !can_checksum_protocol(features, type)) {
3478 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3479 	}
3480 	if (illegal_highdma(skb->dev, skb))
3481 		features &= ~NETIF_F_SG;
3482 
3483 	return features;
3484 }
3485 
3486 netdev_features_t passthru_features_check(struct sk_buff *skb,
3487 					  struct net_device *dev,
3488 					  netdev_features_t features)
3489 {
3490 	return features;
3491 }
3492 EXPORT_SYMBOL(passthru_features_check);
3493 
3494 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3495 					     struct net_device *dev,
3496 					     netdev_features_t features)
3497 {
3498 	return vlan_features_check(skb, features);
3499 }
3500 
3501 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3502 					    struct net_device *dev,
3503 					    netdev_features_t features)
3504 {
3505 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3506 
3507 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3508 		return features & ~NETIF_F_GSO_MASK;
3509 
3510 	if (!skb_shinfo(skb)->gso_type) {
3511 		skb_warn_bad_offload(skb);
3512 		return features & ~NETIF_F_GSO_MASK;
3513 	}
3514 
3515 	/* Support for GSO partial features requires software
3516 	 * intervention before we can actually process the packets
3517 	 * so we need to strip support for any partial features now
3518 	 * and we can pull them back in after we have partially
3519 	 * segmented the frame.
3520 	 */
3521 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3522 		features &= ~dev->gso_partial_features;
3523 
3524 	/* Make sure to clear the IPv4 ID mangling feature if the
3525 	 * IPv4 header has the potential to be fragmented.
3526 	 */
3527 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3528 		struct iphdr *iph = skb->encapsulation ?
3529 				    inner_ip_hdr(skb) : ip_hdr(skb);
3530 
3531 		if (!(iph->frag_off & htons(IP_DF)))
3532 			features &= ~NETIF_F_TSO_MANGLEID;
3533 	}
3534 
3535 	return features;
3536 }
3537 
3538 netdev_features_t netif_skb_features(struct sk_buff *skb)
3539 {
3540 	struct net_device *dev = skb->dev;
3541 	netdev_features_t features = dev->features;
3542 
3543 	if (skb_is_gso(skb))
3544 		features = gso_features_check(skb, dev, features);
3545 
3546 	/* If encapsulation offload request, verify we are testing
3547 	 * hardware encapsulation features instead of standard
3548 	 * features for the netdev
3549 	 */
3550 	if (skb->encapsulation)
3551 		features &= dev->hw_enc_features;
3552 
3553 	if (skb_vlan_tagged(skb))
3554 		features = netdev_intersect_features(features,
3555 						     dev->vlan_features |
3556 						     NETIF_F_HW_VLAN_CTAG_TX |
3557 						     NETIF_F_HW_VLAN_STAG_TX);
3558 
3559 	if (dev->netdev_ops->ndo_features_check)
3560 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3561 								features);
3562 	else
3563 		features &= dflt_features_check(skb, dev, features);
3564 
3565 	return harmonize_features(skb, features);
3566 }
3567 EXPORT_SYMBOL(netif_skb_features);
3568 
3569 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3570 		    struct netdev_queue *txq, bool more)
3571 {
3572 	unsigned int len;
3573 	int rc;
3574 
3575 	if (dev_nit_active(dev))
3576 		dev_queue_xmit_nit(skb, dev);
3577 
3578 	len = skb->len;
3579 	trace_net_dev_start_xmit(skb, dev);
3580 	rc = netdev_start_xmit(skb, dev, txq, more);
3581 	trace_net_dev_xmit(skb, rc, dev, len);
3582 
3583 	return rc;
3584 }
3585 
3586 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3587 				    struct netdev_queue *txq, int *ret)
3588 {
3589 	struct sk_buff *skb = first;
3590 	int rc = NETDEV_TX_OK;
3591 
3592 	while (skb) {
3593 		struct sk_buff *next = skb->next;
3594 
3595 		skb_mark_not_on_list(skb);
3596 		rc = xmit_one(skb, dev, txq, next != NULL);
3597 		if (unlikely(!dev_xmit_complete(rc))) {
3598 			skb->next = next;
3599 			goto out;
3600 		}
3601 
3602 		skb = next;
3603 		if (netif_tx_queue_stopped(txq) && skb) {
3604 			rc = NETDEV_TX_BUSY;
3605 			break;
3606 		}
3607 	}
3608 
3609 out:
3610 	*ret = rc;
3611 	return skb;
3612 }
3613 
3614 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3615 					  netdev_features_t features)
3616 {
3617 	if (skb_vlan_tag_present(skb) &&
3618 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3619 		skb = __vlan_hwaccel_push_inside(skb);
3620 	return skb;
3621 }
3622 
3623 int skb_csum_hwoffload_help(struct sk_buff *skb,
3624 			    const netdev_features_t features)
3625 {
3626 	if (unlikely(skb_csum_is_sctp(skb)))
3627 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3628 			skb_crc32c_csum_help(skb);
3629 
3630 	if (features & NETIF_F_HW_CSUM)
3631 		return 0;
3632 
3633 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3634 		switch (skb->csum_offset) {
3635 		case offsetof(struct tcphdr, check):
3636 		case offsetof(struct udphdr, check):
3637 			return 0;
3638 		}
3639 	}
3640 
3641 	return skb_checksum_help(skb);
3642 }
3643 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3644 
3645 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3646 {
3647 	netdev_features_t features;
3648 
3649 	features = netif_skb_features(skb);
3650 	skb = validate_xmit_vlan(skb, features);
3651 	if (unlikely(!skb))
3652 		goto out_null;
3653 
3654 	skb = sk_validate_xmit_skb(skb, dev);
3655 	if (unlikely(!skb))
3656 		goto out_null;
3657 
3658 	if (netif_needs_gso(skb, features)) {
3659 		struct sk_buff *segs;
3660 
3661 		segs = skb_gso_segment(skb, features);
3662 		if (IS_ERR(segs)) {
3663 			goto out_kfree_skb;
3664 		} else if (segs) {
3665 			consume_skb(skb);
3666 			skb = segs;
3667 		}
3668 	} else {
3669 		if (skb_needs_linearize(skb, features) &&
3670 		    __skb_linearize(skb))
3671 			goto out_kfree_skb;
3672 
3673 		/* If packet is not checksummed and device does not
3674 		 * support checksumming for this protocol, complete
3675 		 * checksumming here.
3676 		 */
3677 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3678 			if (skb->encapsulation)
3679 				skb_set_inner_transport_header(skb,
3680 							       skb_checksum_start_offset(skb));
3681 			else
3682 				skb_set_transport_header(skb,
3683 							 skb_checksum_start_offset(skb));
3684 			if (skb_csum_hwoffload_help(skb, features))
3685 				goto out_kfree_skb;
3686 		}
3687 	}
3688 
3689 	skb = validate_xmit_xfrm(skb, features, again);
3690 
3691 	return skb;
3692 
3693 out_kfree_skb:
3694 	kfree_skb(skb);
3695 out_null:
3696 	dev_core_stats_tx_dropped_inc(dev);
3697 	return NULL;
3698 }
3699 
3700 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3701 {
3702 	struct sk_buff *next, *head = NULL, *tail;
3703 
3704 	for (; skb != NULL; skb = next) {
3705 		next = skb->next;
3706 		skb_mark_not_on_list(skb);
3707 
3708 		/* in case skb wont be segmented, point to itself */
3709 		skb->prev = skb;
3710 
3711 		skb = validate_xmit_skb(skb, dev, again);
3712 		if (!skb)
3713 			continue;
3714 
3715 		if (!head)
3716 			head = skb;
3717 		else
3718 			tail->next = skb;
3719 		/* If skb was segmented, skb->prev points to
3720 		 * the last segment. If not, it still contains skb.
3721 		 */
3722 		tail = skb->prev;
3723 	}
3724 	return head;
3725 }
3726 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3727 
3728 static void qdisc_pkt_len_init(struct sk_buff *skb)
3729 {
3730 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3731 
3732 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3733 
3734 	/* To get more precise estimation of bytes sent on wire,
3735 	 * we add to pkt_len the headers size of all segments
3736 	 */
3737 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3738 		u16 gso_segs = shinfo->gso_segs;
3739 		unsigned int hdr_len;
3740 
3741 		/* mac layer + network layer */
3742 		hdr_len = skb_transport_offset(skb);
3743 
3744 		/* + transport layer */
3745 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3746 			const struct tcphdr *th;
3747 			struct tcphdr _tcphdr;
3748 
3749 			th = skb_header_pointer(skb, hdr_len,
3750 						sizeof(_tcphdr), &_tcphdr);
3751 			if (likely(th))
3752 				hdr_len += __tcp_hdrlen(th);
3753 		} else {
3754 			struct udphdr _udphdr;
3755 
3756 			if (skb_header_pointer(skb, hdr_len,
3757 					       sizeof(_udphdr), &_udphdr))
3758 				hdr_len += sizeof(struct udphdr);
3759 		}
3760 
3761 		if (shinfo->gso_type & SKB_GSO_DODGY)
3762 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3763 						shinfo->gso_size);
3764 
3765 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3766 	}
3767 }
3768 
3769 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3770 			     struct sk_buff **to_free,
3771 			     struct netdev_queue *txq)
3772 {
3773 	int rc;
3774 
3775 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3776 	if (rc == NET_XMIT_SUCCESS)
3777 		trace_qdisc_enqueue(q, txq, skb);
3778 	return rc;
3779 }
3780 
3781 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3782 				 struct net_device *dev,
3783 				 struct netdev_queue *txq)
3784 {
3785 	spinlock_t *root_lock = qdisc_lock(q);
3786 	struct sk_buff *to_free = NULL;
3787 	bool contended;
3788 	int rc;
3789 
3790 	qdisc_calculate_pkt_len(skb, q);
3791 
3792 	if (q->flags & TCQ_F_NOLOCK) {
3793 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3794 		    qdisc_run_begin(q)) {
3795 			/* Retest nolock_qdisc_is_empty() within the protection
3796 			 * of q->seqlock to protect from racing with requeuing.
3797 			 */
3798 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3799 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3800 				__qdisc_run(q);
3801 				qdisc_run_end(q);
3802 
3803 				goto no_lock_out;
3804 			}
3805 
3806 			qdisc_bstats_cpu_update(q, skb);
3807 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3808 			    !nolock_qdisc_is_empty(q))
3809 				__qdisc_run(q);
3810 
3811 			qdisc_run_end(q);
3812 			return NET_XMIT_SUCCESS;
3813 		}
3814 
3815 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3816 		qdisc_run(q);
3817 
3818 no_lock_out:
3819 		if (unlikely(to_free))
3820 			kfree_skb_list_reason(to_free,
3821 					      SKB_DROP_REASON_QDISC_DROP);
3822 		return rc;
3823 	}
3824 
3825 	/*
3826 	 * Heuristic to force contended enqueues to serialize on a
3827 	 * separate lock before trying to get qdisc main lock.
3828 	 * This permits qdisc->running owner to get the lock more
3829 	 * often and dequeue packets faster.
3830 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3831 	 * and then other tasks will only enqueue packets. The packets will be
3832 	 * sent after the qdisc owner is scheduled again. To prevent this
3833 	 * scenario the task always serialize on the lock.
3834 	 */
3835 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3836 	if (unlikely(contended))
3837 		spin_lock(&q->busylock);
3838 
3839 	spin_lock(root_lock);
3840 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3841 		__qdisc_drop(skb, &to_free);
3842 		rc = NET_XMIT_DROP;
3843 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3844 		   qdisc_run_begin(q)) {
3845 		/*
3846 		 * This is a work-conserving queue; there are no old skbs
3847 		 * waiting to be sent out; and the qdisc is not running -
3848 		 * xmit the skb directly.
3849 		 */
3850 
3851 		qdisc_bstats_update(q, skb);
3852 
3853 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3854 			if (unlikely(contended)) {
3855 				spin_unlock(&q->busylock);
3856 				contended = false;
3857 			}
3858 			__qdisc_run(q);
3859 		}
3860 
3861 		qdisc_run_end(q);
3862 		rc = NET_XMIT_SUCCESS;
3863 	} else {
3864 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3865 		if (qdisc_run_begin(q)) {
3866 			if (unlikely(contended)) {
3867 				spin_unlock(&q->busylock);
3868 				contended = false;
3869 			}
3870 			__qdisc_run(q);
3871 			qdisc_run_end(q);
3872 		}
3873 	}
3874 	spin_unlock(root_lock);
3875 	if (unlikely(to_free))
3876 		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3877 	if (unlikely(contended))
3878 		spin_unlock(&q->busylock);
3879 	return rc;
3880 }
3881 
3882 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3883 static void skb_update_prio(struct sk_buff *skb)
3884 {
3885 	const struct netprio_map *map;
3886 	const struct sock *sk;
3887 	unsigned int prioidx;
3888 
3889 	if (skb->priority)
3890 		return;
3891 	map = rcu_dereference_bh(skb->dev->priomap);
3892 	if (!map)
3893 		return;
3894 	sk = skb_to_full_sk(skb);
3895 	if (!sk)
3896 		return;
3897 
3898 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3899 
3900 	if (prioidx < map->priomap_len)
3901 		skb->priority = map->priomap[prioidx];
3902 }
3903 #else
3904 #define skb_update_prio(skb)
3905 #endif
3906 
3907 /**
3908  *	dev_loopback_xmit - loop back @skb
3909  *	@net: network namespace this loopback is happening in
3910  *	@sk:  sk needed to be a netfilter okfn
3911  *	@skb: buffer to transmit
3912  */
3913 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3914 {
3915 	skb_reset_mac_header(skb);
3916 	__skb_pull(skb, skb_network_offset(skb));
3917 	skb->pkt_type = PACKET_LOOPBACK;
3918 	if (skb->ip_summed == CHECKSUM_NONE)
3919 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3920 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3921 	skb_dst_force(skb);
3922 	netif_rx(skb);
3923 	return 0;
3924 }
3925 EXPORT_SYMBOL(dev_loopback_xmit);
3926 
3927 #ifdef CONFIG_NET_EGRESS
3928 static struct sk_buff *
3929 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3930 {
3931 #ifdef CONFIG_NET_CLS_ACT
3932 	struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3933 	struct tcf_result cl_res;
3934 
3935 	if (!miniq)
3936 		return skb;
3937 
3938 	/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3939 	tc_skb_cb(skb)->mru = 0;
3940 	tc_skb_cb(skb)->post_ct = false;
3941 	mini_qdisc_bstats_cpu_update(miniq, skb);
3942 
3943 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3944 	case TC_ACT_OK:
3945 	case TC_ACT_RECLASSIFY:
3946 		skb->tc_index = TC_H_MIN(cl_res.classid);
3947 		break;
3948 	case TC_ACT_SHOT:
3949 		mini_qdisc_qstats_cpu_drop(miniq);
3950 		*ret = NET_XMIT_DROP;
3951 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
3952 		return NULL;
3953 	case TC_ACT_STOLEN:
3954 	case TC_ACT_QUEUED:
3955 	case TC_ACT_TRAP:
3956 		*ret = NET_XMIT_SUCCESS;
3957 		consume_skb(skb);
3958 		return NULL;
3959 	case TC_ACT_REDIRECT:
3960 		/* No need to push/pop skb's mac_header here on egress! */
3961 		skb_do_redirect(skb);
3962 		*ret = NET_XMIT_SUCCESS;
3963 		return NULL;
3964 	default:
3965 		break;
3966 	}
3967 #endif /* CONFIG_NET_CLS_ACT */
3968 
3969 	return skb;
3970 }
3971 
3972 static struct netdev_queue *
3973 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3974 {
3975 	int qm = skb_get_queue_mapping(skb);
3976 
3977 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3978 }
3979 
3980 static bool netdev_xmit_txqueue_skipped(void)
3981 {
3982 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3983 }
3984 
3985 void netdev_xmit_skip_txqueue(bool skip)
3986 {
3987 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3988 }
3989 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3990 #endif /* CONFIG_NET_EGRESS */
3991 
3992 #ifdef CONFIG_XPS
3993 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
3994 			       struct xps_dev_maps *dev_maps, unsigned int tci)
3995 {
3996 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
3997 	struct xps_map *map;
3998 	int queue_index = -1;
3999 
4000 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4001 		return queue_index;
4002 
4003 	tci *= dev_maps->num_tc;
4004 	tci += tc;
4005 
4006 	map = rcu_dereference(dev_maps->attr_map[tci]);
4007 	if (map) {
4008 		if (map->len == 1)
4009 			queue_index = map->queues[0];
4010 		else
4011 			queue_index = map->queues[reciprocal_scale(
4012 						skb_get_hash(skb), map->len)];
4013 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4014 			queue_index = -1;
4015 	}
4016 	return queue_index;
4017 }
4018 #endif
4019 
4020 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4021 			 struct sk_buff *skb)
4022 {
4023 #ifdef CONFIG_XPS
4024 	struct xps_dev_maps *dev_maps;
4025 	struct sock *sk = skb->sk;
4026 	int queue_index = -1;
4027 
4028 	if (!static_key_false(&xps_needed))
4029 		return -1;
4030 
4031 	rcu_read_lock();
4032 	if (!static_key_false(&xps_rxqs_needed))
4033 		goto get_cpus_map;
4034 
4035 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4036 	if (dev_maps) {
4037 		int tci = sk_rx_queue_get(sk);
4038 
4039 		if (tci >= 0)
4040 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4041 							  tci);
4042 	}
4043 
4044 get_cpus_map:
4045 	if (queue_index < 0) {
4046 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4047 		if (dev_maps) {
4048 			unsigned int tci = skb->sender_cpu - 1;
4049 
4050 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4051 							  tci);
4052 		}
4053 	}
4054 	rcu_read_unlock();
4055 
4056 	return queue_index;
4057 #else
4058 	return -1;
4059 #endif
4060 }
4061 
4062 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4063 		     struct net_device *sb_dev)
4064 {
4065 	return 0;
4066 }
4067 EXPORT_SYMBOL(dev_pick_tx_zero);
4068 
4069 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4070 		       struct net_device *sb_dev)
4071 {
4072 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4073 }
4074 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4075 
4076 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4077 		     struct net_device *sb_dev)
4078 {
4079 	struct sock *sk = skb->sk;
4080 	int queue_index = sk_tx_queue_get(sk);
4081 
4082 	sb_dev = sb_dev ? : dev;
4083 
4084 	if (queue_index < 0 || skb->ooo_okay ||
4085 	    queue_index >= dev->real_num_tx_queues) {
4086 		int new_index = get_xps_queue(dev, sb_dev, skb);
4087 
4088 		if (new_index < 0)
4089 			new_index = skb_tx_hash(dev, sb_dev, skb);
4090 
4091 		if (queue_index != new_index && sk &&
4092 		    sk_fullsock(sk) &&
4093 		    rcu_access_pointer(sk->sk_dst_cache))
4094 			sk_tx_queue_set(sk, new_index);
4095 
4096 		queue_index = new_index;
4097 	}
4098 
4099 	return queue_index;
4100 }
4101 EXPORT_SYMBOL(netdev_pick_tx);
4102 
4103 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4104 					 struct sk_buff *skb,
4105 					 struct net_device *sb_dev)
4106 {
4107 	int queue_index = 0;
4108 
4109 #ifdef CONFIG_XPS
4110 	u32 sender_cpu = skb->sender_cpu - 1;
4111 
4112 	if (sender_cpu >= (u32)NR_CPUS)
4113 		skb->sender_cpu = raw_smp_processor_id() + 1;
4114 #endif
4115 
4116 	if (dev->real_num_tx_queues != 1) {
4117 		const struct net_device_ops *ops = dev->netdev_ops;
4118 
4119 		if (ops->ndo_select_queue)
4120 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4121 		else
4122 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4123 
4124 		queue_index = netdev_cap_txqueue(dev, queue_index);
4125 	}
4126 
4127 	skb_set_queue_mapping(skb, queue_index);
4128 	return netdev_get_tx_queue(dev, queue_index);
4129 }
4130 
4131 /**
4132  * __dev_queue_xmit() - transmit a buffer
4133  * @skb:	buffer to transmit
4134  * @sb_dev:	suboordinate device used for L2 forwarding offload
4135  *
4136  * Queue a buffer for transmission to a network device. The caller must
4137  * have set the device and priority and built the buffer before calling
4138  * this function. The function can be called from an interrupt.
4139  *
4140  * When calling this method, interrupts MUST be enabled. This is because
4141  * the BH enable code must have IRQs enabled so that it will not deadlock.
4142  *
4143  * Regardless of the return value, the skb is consumed, so it is currently
4144  * difficult to retry a send to this method. (You can bump the ref count
4145  * before sending to hold a reference for retry if you are careful.)
4146  *
4147  * Return:
4148  * * 0				- buffer successfully transmitted
4149  * * positive qdisc return code	- NET_XMIT_DROP etc.
4150  * * negative errno		- other errors
4151  */
4152 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4153 {
4154 	struct net_device *dev = skb->dev;
4155 	struct netdev_queue *txq = NULL;
4156 	struct Qdisc *q;
4157 	int rc = -ENOMEM;
4158 	bool again = false;
4159 
4160 	skb_reset_mac_header(skb);
4161 	skb_assert_len(skb);
4162 
4163 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4164 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4165 
4166 	/* Disable soft irqs for various locks below. Also
4167 	 * stops preemption for RCU.
4168 	 */
4169 	rcu_read_lock_bh();
4170 
4171 	skb_update_prio(skb);
4172 
4173 	qdisc_pkt_len_init(skb);
4174 #ifdef CONFIG_NET_CLS_ACT
4175 	skb->tc_at_ingress = 0;
4176 #endif
4177 #ifdef CONFIG_NET_EGRESS
4178 	if (static_branch_unlikely(&egress_needed_key)) {
4179 		if (nf_hook_egress_active()) {
4180 			skb = nf_hook_egress(skb, &rc, dev);
4181 			if (!skb)
4182 				goto out;
4183 		}
4184 
4185 		netdev_xmit_skip_txqueue(false);
4186 
4187 		nf_skip_egress(skb, true);
4188 		skb = sch_handle_egress(skb, &rc, dev);
4189 		if (!skb)
4190 			goto out;
4191 		nf_skip_egress(skb, false);
4192 
4193 		if (netdev_xmit_txqueue_skipped())
4194 			txq = netdev_tx_queue_mapping(dev, skb);
4195 	}
4196 #endif
4197 	/* If device/qdisc don't need skb->dst, release it right now while
4198 	 * its hot in this cpu cache.
4199 	 */
4200 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4201 		skb_dst_drop(skb);
4202 	else
4203 		skb_dst_force(skb);
4204 
4205 	if (!txq)
4206 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4207 
4208 	q = rcu_dereference_bh(txq->qdisc);
4209 
4210 	trace_net_dev_queue(skb);
4211 	if (q->enqueue) {
4212 		rc = __dev_xmit_skb(skb, q, dev, txq);
4213 		goto out;
4214 	}
4215 
4216 	/* The device has no queue. Common case for software devices:
4217 	 * loopback, all the sorts of tunnels...
4218 
4219 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4220 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4221 	 * counters.)
4222 	 * However, it is possible, that they rely on protection
4223 	 * made by us here.
4224 
4225 	 * Check this and shot the lock. It is not prone from deadlocks.
4226 	 *Either shot noqueue qdisc, it is even simpler 8)
4227 	 */
4228 	if (dev->flags & IFF_UP) {
4229 		int cpu = smp_processor_id(); /* ok because BHs are off */
4230 
4231 		/* Other cpus might concurrently change txq->xmit_lock_owner
4232 		 * to -1 or to their cpu id, but not to our id.
4233 		 */
4234 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4235 			if (dev_xmit_recursion())
4236 				goto recursion_alert;
4237 
4238 			skb = validate_xmit_skb(skb, dev, &again);
4239 			if (!skb)
4240 				goto out;
4241 
4242 			HARD_TX_LOCK(dev, txq, cpu);
4243 
4244 			if (!netif_xmit_stopped(txq)) {
4245 				dev_xmit_recursion_inc();
4246 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4247 				dev_xmit_recursion_dec();
4248 				if (dev_xmit_complete(rc)) {
4249 					HARD_TX_UNLOCK(dev, txq);
4250 					goto out;
4251 				}
4252 			}
4253 			HARD_TX_UNLOCK(dev, txq);
4254 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4255 					     dev->name);
4256 		} else {
4257 			/* Recursion is detected! It is possible,
4258 			 * unfortunately
4259 			 */
4260 recursion_alert:
4261 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4262 					     dev->name);
4263 		}
4264 	}
4265 
4266 	rc = -ENETDOWN;
4267 	rcu_read_unlock_bh();
4268 
4269 	dev_core_stats_tx_dropped_inc(dev);
4270 	kfree_skb_list(skb);
4271 	return rc;
4272 out:
4273 	rcu_read_unlock_bh();
4274 	return rc;
4275 }
4276 EXPORT_SYMBOL(__dev_queue_xmit);
4277 
4278 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4279 {
4280 	struct net_device *dev = skb->dev;
4281 	struct sk_buff *orig_skb = skb;
4282 	struct netdev_queue *txq;
4283 	int ret = NETDEV_TX_BUSY;
4284 	bool again = false;
4285 
4286 	if (unlikely(!netif_running(dev) ||
4287 		     !netif_carrier_ok(dev)))
4288 		goto drop;
4289 
4290 	skb = validate_xmit_skb_list(skb, dev, &again);
4291 	if (skb != orig_skb)
4292 		goto drop;
4293 
4294 	skb_set_queue_mapping(skb, queue_id);
4295 	txq = skb_get_tx_queue(dev, skb);
4296 
4297 	local_bh_disable();
4298 
4299 	dev_xmit_recursion_inc();
4300 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4301 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4302 		ret = netdev_start_xmit(skb, dev, txq, false);
4303 	HARD_TX_UNLOCK(dev, txq);
4304 	dev_xmit_recursion_dec();
4305 
4306 	local_bh_enable();
4307 	return ret;
4308 drop:
4309 	dev_core_stats_tx_dropped_inc(dev);
4310 	kfree_skb_list(skb);
4311 	return NET_XMIT_DROP;
4312 }
4313 EXPORT_SYMBOL(__dev_direct_xmit);
4314 
4315 /*************************************************************************
4316  *			Receiver routines
4317  *************************************************************************/
4318 
4319 int netdev_max_backlog __read_mostly = 1000;
4320 EXPORT_SYMBOL(netdev_max_backlog);
4321 
4322 int netdev_tstamp_prequeue __read_mostly = 1;
4323 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4324 int netdev_budget __read_mostly = 300;
4325 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4326 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4327 int weight_p __read_mostly = 64;           /* old backlog weight */
4328 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4329 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4330 int dev_rx_weight __read_mostly = 64;
4331 int dev_tx_weight __read_mostly = 64;
4332 
4333 /* Called with irq disabled */
4334 static inline void ____napi_schedule(struct softnet_data *sd,
4335 				     struct napi_struct *napi)
4336 {
4337 	struct task_struct *thread;
4338 
4339 	lockdep_assert_irqs_disabled();
4340 
4341 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4342 		/* Paired with smp_mb__before_atomic() in
4343 		 * napi_enable()/dev_set_threaded().
4344 		 * Use READ_ONCE() to guarantee a complete
4345 		 * read on napi->thread. Only call
4346 		 * wake_up_process() when it's not NULL.
4347 		 */
4348 		thread = READ_ONCE(napi->thread);
4349 		if (thread) {
4350 			/* Avoid doing set_bit() if the thread is in
4351 			 * INTERRUPTIBLE state, cause napi_thread_wait()
4352 			 * makes sure to proceed with napi polling
4353 			 * if the thread is explicitly woken from here.
4354 			 */
4355 			if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4356 				set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4357 			wake_up_process(thread);
4358 			return;
4359 		}
4360 	}
4361 
4362 	list_add_tail(&napi->poll_list, &sd->poll_list);
4363 	/* If not called from net_rx_action()
4364 	 * we have to raise NET_RX_SOFTIRQ.
4365 	 */
4366 	if (!sd->in_net_rx_action)
4367 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4368 }
4369 
4370 #ifdef CONFIG_RPS
4371 
4372 /* One global table that all flow-based protocols share. */
4373 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4374 EXPORT_SYMBOL(rps_sock_flow_table);
4375 u32 rps_cpu_mask __read_mostly;
4376 EXPORT_SYMBOL(rps_cpu_mask);
4377 
4378 struct static_key_false rps_needed __read_mostly;
4379 EXPORT_SYMBOL(rps_needed);
4380 struct static_key_false rfs_needed __read_mostly;
4381 EXPORT_SYMBOL(rfs_needed);
4382 
4383 static struct rps_dev_flow *
4384 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4385 	    struct rps_dev_flow *rflow, u16 next_cpu)
4386 {
4387 	if (next_cpu < nr_cpu_ids) {
4388 #ifdef CONFIG_RFS_ACCEL
4389 		struct netdev_rx_queue *rxqueue;
4390 		struct rps_dev_flow_table *flow_table;
4391 		struct rps_dev_flow *old_rflow;
4392 		u32 flow_id;
4393 		u16 rxq_index;
4394 		int rc;
4395 
4396 		/* Should we steer this flow to a different hardware queue? */
4397 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4398 		    !(dev->features & NETIF_F_NTUPLE))
4399 			goto out;
4400 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4401 		if (rxq_index == skb_get_rx_queue(skb))
4402 			goto out;
4403 
4404 		rxqueue = dev->_rx + rxq_index;
4405 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4406 		if (!flow_table)
4407 			goto out;
4408 		flow_id = skb_get_hash(skb) & flow_table->mask;
4409 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4410 							rxq_index, flow_id);
4411 		if (rc < 0)
4412 			goto out;
4413 		old_rflow = rflow;
4414 		rflow = &flow_table->flows[flow_id];
4415 		rflow->filter = rc;
4416 		if (old_rflow->filter == rflow->filter)
4417 			old_rflow->filter = RPS_NO_FILTER;
4418 	out:
4419 #endif
4420 		rflow->last_qtail =
4421 			per_cpu(softnet_data, next_cpu).input_queue_head;
4422 	}
4423 
4424 	rflow->cpu = next_cpu;
4425 	return rflow;
4426 }
4427 
4428 /*
4429  * get_rps_cpu is called from netif_receive_skb and returns the target
4430  * CPU from the RPS map of the receiving queue for a given skb.
4431  * rcu_read_lock must be held on entry.
4432  */
4433 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4434 		       struct rps_dev_flow **rflowp)
4435 {
4436 	const struct rps_sock_flow_table *sock_flow_table;
4437 	struct netdev_rx_queue *rxqueue = dev->_rx;
4438 	struct rps_dev_flow_table *flow_table;
4439 	struct rps_map *map;
4440 	int cpu = -1;
4441 	u32 tcpu;
4442 	u32 hash;
4443 
4444 	if (skb_rx_queue_recorded(skb)) {
4445 		u16 index = skb_get_rx_queue(skb);
4446 
4447 		if (unlikely(index >= dev->real_num_rx_queues)) {
4448 			WARN_ONCE(dev->real_num_rx_queues > 1,
4449 				  "%s received packet on queue %u, but number "
4450 				  "of RX queues is %u\n",
4451 				  dev->name, index, dev->real_num_rx_queues);
4452 			goto done;
4453 		}
4454 		rxqueue += index;
4455 	}
4456 
4457 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4458 
4459 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4460 	map = rcu_dereference(rxqueue->rps_map);
4461 	if (!flow_table && !map)
4462 		goto done;
4463 
4464 	skb_reset_network_header(skb);
4465 	hash = skb_get_hash(skb);
4466 	if (!hash)
4467 		goto done;
4468 
4469 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
4470 	if (flow_table && sock_flow_table) {
4471 		struct rps_dev_flow *rflow;
4472 		u32 next_cpu;
4473 		u32 ident;
4474 
4475 		/* First check into global flow table if there is a match */
4476 		ident = sock_flow_table->ents[hash & sock_flow_table->mask];
4477 		if ((ident ^ hash) & ~rps_cpu_mask)
4478 			goto try_rps;
4479 
4480 		next_cpu = ident & rps_cpu_mask;
4481 
4482 		/* OK, now we know there is a match,
4483 		 * we can look at the local (per receive queue) flow table
4484 		 */
4485 		rflow = &flow_table->flows[hash & flow_table->mask];
4486 		tcpu = rflow->cpu;
4487 
4488 		/*
4489 		 * If the desired CPU (where last recvmsg was done) is
4490 		 * different from current CPU (one in the rx-queue flow
4491 		 * table entry), switch if one of the following holds:
4492 		 *   - Current CPU is unset (>= nr_cpu_ids).
4493 		 *   - Current CPU is offline.
4494 		 *   - The current CPU's queue tail has advanced beyond the
4495 		 *     last packet that was enqueued using this table entry.
4496 		 *     This guarantees that all previous packets for the flow
4497 		 *     have been dequeued, thus preserving in order delivery.
4498 		 */
4499 		if (unlikely(tcpu != next_cpu) &&
4500 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4501 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4502 		      rflow->last_qtail)) >= 0)) {
4503 			tcpu = next_cpu;
4504 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4505 		}
4506 
4507 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4508 			*rflowp = rflow;
4509 			cpu = tcpu;
4510 			goto done;
4511 		}
4512 	}
4513 
4514 try_rps:
4515 
4516 	if (map) {
4517 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4518 		if (cpu_online(tcpu)) {
4519 			cpu = tcpu;
4520 			goto done;
4521 		}
4522 	}
4523 
4524 done:
4525 	return cpu;
4526 }
4527 
4528 #ifdef CONFIG_RFS_ACCEL
4529 
4530 /**
4531  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4532  * @dev: Device on which the filter was set
4533  * @rxq_index: RX queue index
4534  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4535  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4536  *
4537  * Drivers that implement ndo_rx_flow_steer() should periodically call
4538  * this function for each installed filter and remove the filters for
4539  * which it returns %true.
4540  */
4541 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4542 			 u32 flow_id, u16 filter_id)
4543 {
4544 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4545 	struct rps_dev_flow_table *flow_table;
4546 	struct rps_dev_flow *rflow;
4547 	bool expire = true;
4548 	unsigned int cpu;
4549 
4550 	rcu_read_lock();
4551 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4552 	if (flow_table && flow_id <= flow_table->mask) {
4553 		rflow = &flow_table->flows[flow_id];
4554 		cpu = READ_ONCE(rflow->cpu);
4555 		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4556 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4557 			   rflow->last_qtail) <
4558 		     (int)(10 * flow_table->mask)))
4559 			expire = false;
4560 	}
4561 	rcu_read_unlock();
4562 	return expire;
4563 }
4564 EXPORT_SYMBOL(rps_may_expire_flow);
4565 
4566 #endif /* CONFIG_RFS_ACCEL */
4567 
4568 /* Called from hardirq (IPI) context */
4569 static void rps_trigger_softirq(void *data)
4570 {
4571 	struct softnet_data *sd = data;
4572 
4573 	____napi_schedule(sd, &sd->backlog);
4574 	sd->received_rps++;
4575 }
4576 
4577 #endif /* CONFIG_RPS */
4578 
4579 /* Called from hardirq (IPI) context */
4580 static void trigger_rx_softirq(void *data)
4581 {
4582 	struct softnet_data *sd = data;
4583 
4584 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4585 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4586 }
4587 
4588 /*
4589  * After we queued a packet into sd->input_pkt_queue,
4590  * we need to make sure this queue is serviced soon.
4591  *
4592  * - If this is another cpu queue, link it to our rps_ipi_list,
4593  *   and make sure we will process rps_ipi_list from net_rx_action().
4594  *
4595  * - If this is our own queue, NAPI schedule our backlog.
4596  *   Note that this also raises NET_RX_SOFTIRQ.
4597  */
4598 static void napi_schedule_rps(struct softnet_data *sd)
4599 {
4600 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4601 
4602 #ifdef CONFIG_RPS
4603 	if (sd != mysd) {
4604 		sd->rps_ipi_next = mysd->rps_ipi_list;
4605 		mysd->rps_ipi_list = sd;
4606 
4607 		/* If not called from net_rx_action()
4608 		 * we have to raise NET_RX_SOFTIRQ.
4609 		 */
4610 		if (!mysd->in_net_rx_action)
4611 			__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4612 		return;
4613 	}
4614 #endif /* CONFIG_RPS */
4615 	__napi_schedule_irqoff(&mysd->backlog);
4616 }
4617 
4618 #ifdef CONFIG_NET_FLOW_LIMIT
4619 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4620 #endif
4621 
4622 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4623 {
4624 #ifdef CONFIG_NET_FLOW_LIMIT
4625 	struct sd_flow_limit *fl;
4626 	struct softnet_data *sd;
4627 	unsigned int old_flow, new_flow;
4628 
4629 	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4630 		return false;
4631 
4632 	sd = this_cpu_ptr(&softnet_data);
4633 
4634 	rcu_read_lock();
4635 	fl = rcu_dereference(sd->flow_limit);
4636 	if (fl) {
4637 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4638 		old_flow = fl->history[fl->history_head];
4639 		fl->history[fl->history_head] = new_flow;
4640 
4641 		fl->history_head++;
4642 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4643 
4644 		if (likely(fl->buckets[old_flow]))
4645 			fl->buckets[old_flow]--;
4646 
4647 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4648 			fl->count++;
4649 			rcu_read_unlock();
4650 			return true;
4651 		}
4652 	}
4653 	rcu_read_unlock();
4654 #endif
4655 	return false;
4656 }
4657 
4658 /*
4659  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4660  * queue (may be a remote CPU queue).
4661  */
4662 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4663 			      unsigned int *qtail)
4664 {
4665 	enum skb_drop_reason reason;
4666 	struct softnet_data *sd;
4667 	unsigned long flags;
4668 	unsigned int qlen;
4669 
4670 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
4671 	sd = &per_cpu(softnet_data, cpu);
4672 
4673 	rps_lock_irqsave(sd, &flags);
4674 	if (!netif_running(skb->dev))
4675 		goto drop;
4676 	qlen = skb_queue_len(&sd->input_pkt_queue);
4677 	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4678 		if (qlen) {
4679 enqueue:
4680 			__skb_queue_tail(&sd->input_pkt_queue, skb);
4681 			input_queue_tail_incr_save(sd, qtail);
4682 			rps_unlock_irq_restore(sd, &flags);
4683 			return NET_RX_SUCCESS;
4684 		}
4685 
4686 		/* Schedule NAPI for backlog device
4687 		 * We can use non atomic operation since we own the queue lock
4688 		 */
4689 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4690 			napi_schedule_rps(sd);
4691 		goto enqueue;
4692 	}
4693 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4694 
4695 drop:
4696 	sd->dropped++;
4697 	rps_unlock_irq_restore(sd, &flags);
4698 
4699 	dev_core_stats_rx_dropped_inc(skb->dev);
4700 	kfree_skb_reason(skb, reason);
4701 	return NET_RX_DROP;
4702 }
4703 
4704 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4705 {
4706 	struct net_device *dev = skb->dev;
4707 	struct netdev_rx_queue *rxqueue;
4708 
4709 	rxqueue = dev->_rx;
4710 
4711 	if (skb_rx_queue_recorded(skb)) {
4712 		u16 index = skb_get_rx_queue(skb);
4713 
4714 		if (unlikely(index >= dev->real_num_rx_queues)) {
4715 			WARN_ONCE(dev->real_num_rx_queues > 1,
4716 				  "%s received packet on queue %u, but number "
4717 				  "of RX queues is %u\n",
4718 				  dev->name, index, dev->real_num_rx_queues);
4719 
4720 			return rxqueue; /* Return first rxqueue */
4721 		}
4722 		rxqueue += index;
4723 	}
4724 	return rxqueue;
4725 }
4726 
4727 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4728 			     struct bpf_prog *xdp_prog)
4729 {
4730 	void *orig_data, *orig_data_end, *hard_start;
4731 	struct netdev_rx_queue *rxqueue;
4732 	bool orig_bcast, orig_host;
4733 	u32 mac_len, frame_sz;
4734 	__be16 orig_eth_type;
4735 	struct ethhdr *eth;
4736 	u32 metalen, act;
4737 	int off;
4738 
4739 	/* The XDP program wants to see the packet starting at the MAC
4740 	 * header.
4741 	 */
4742 	mac_len = skb->data - skb_mac_header(skb);
4743 	hard_start = skb->data - skb_headroom(skb);
4744 
4745 	/* SKB "head" area always have tailroom for skb_shared_info */
4746 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4747 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4748 
4749 	rxqueue = netif_get_rxqueue(skb);
4750 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4751 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4752 			 skb_headlen(skb) + mac_len, true);
4753 
4754 	orig_data_end = xdp->data_end;
4755 	orig_data = xdp->data;
4756 	eth = (struct ethhdr *)xdp->data;
4757 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4758 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4759 	orig_eth_type = eth->h_proto;
4760 
4761 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4762 
4763 	/* check if bpf_xdp_adjust_head was used */
4764 	off = xdp->data - orig_data;
4765 	if (off) {
4766 		if (off > 0)
4767 			__skb_pull(skb, off);
4768 		else if (off < 0)
4769 			__skb_push(skb, -off);
4770 
4771 		skb->mac_header += off;
4772 		skb_reset_network_header(skb);
4773 	}
4774 
4775 	/* check if bpf_xdp_adjust_tail was used */
4776 	off = xdp->data_end - orig_data_end;
4777 	if (off != 0) {
4778 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4779 		skb->len += off; /* positive on grow, negative on shrink */
4780 	}
4781 
4782 	/* check if XDP changed eth hdr such SKB needs update */
4783 	eth = (struct ethhdr *)xdp->data;
4784 	if ((orig_eth_type != eth->h_proto) ||
4785 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4786 						  skb->dev->dev_addr)) ||
4787 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4788 		__skb_push(skb, ETH_HLEN);
4789 		skb->pkt_type = PACKET_HOST;
4790 		skb->protocol = eth_type_trans(skb, skb->dev);
4791 	}
4792 
4793 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4794 	 * before calling us again on redirect path. We do not call do_redirect
4795 	 * as we leave that up to the caller.
4796 	 *
4797 	 * Caller is responsible for managing lifetime of skb (i.e. calling
4798 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
4799 	 */
4800 	switch (act) {
4801 	case XDP_REDIRECT:
4802 	case XDP_TX:
4803 		__skb_push(skb, mac_len);
4804 		break;
4805 	case XDP_PASS:
4806 		metalen = xdp->data - xdp->data_meta;
4807 		if (metalen)
4808 			skb_metadata_set(skb, metalen);
4809 		break;
4810 	}
4811 
4812 	return act;
4813 }
4814 
4815 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4816 				     struct xdp_buff *xdp,
4817 				     struct bpf_prog *xdp_prog)
4818 {
4819 	u32 act = XDP_DROP;
4820 
4821 	/* Reinjected packets coming from act_mirred or similar should
4822 	 * not get XDP generic processing.
4823 	 */
4824 	if (skb_is_redirected(skb))
4825 		return XDP_PASS;
4826 
4827 	/* XDP packets must be linear and must have sufficient headroom
4828 	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4829 	 * native XDP provides, thus we need to do it here as well.
4830 	 */
4831 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4832 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4833 		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4834 		int troom = skb->tail + skb->data_len - skb->end;
4835 
4836 		/* In case we have to go down the path and also linearize,
4837 		 * then lets do the pskb_expand_head() work just once here.
4838 		 */
4839 		if (pskb_expand_head(skb,
4840 				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4841 				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4842 			goto do_drop;
4843 		if (skb_linearize(skb))
4844 			goto do_drop;
4845 	}
4846 
4847 	act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4848 	switch (act) {
4849 	case XDP_REDIRECT:
4850 	case XDP_TX:
4851 	case XDP_PASS:
4852 		break;
4853 	default:
4854 		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4855 		fallthrough;
4856 	case XDP_ABORTED:
4857 		trace_xdp_exception(skb->dev, xdp_prog, act);
4858 		fallthrough;
4859 	case XDP_DROP:
4860 	do_drop:
4861 		kfree_skb(skb);
4862 		break;
4863 	}
4864 
4865 	return act;
4866 }
4867 
4868 /* When doing generic XDP we have to bypass the qdisc layer and the
4869  * network taps in order to match in-driver-XDP behavior. This also means
4870  * that XDP packets are able to starve other packets going through a qdisc,
4871  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
4872  * queues, so they do not have this starvation issue.
4873  */
4874 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4875 {
4876 	struct net_device *dev = skb->dev;
4877 	struct netdev_queue *txq;
4878 	bool free_skb = true;
4879 	int cpu, rc;
4880 
4881 	txq = netdev_core_pick_tx(dev, skb, NULL);
4882 	cpu = smp_processor_id();
4883 	HARD_TX_LOCK(dev, txq, cpu);
4884 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
4885 		rc = netdev_start_xmit(skb, dev, txq, 0);
4886 		if (dev_xmit_complete(rc))
4887 			free_skb = false;
4888 	}
4889 	HARD_TX_UNLOCK(dev, txq);
4890 	if (free_skb) {
4891 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
4892 		dev_core_stats_tx_dropped_inc(dev);
4893 		kfree_skb(skb);
4894 	}
4895 }
4896 
4897 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4898 
4899 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4900 {
4901 	if (xdp_prog) {
4902 		struct xdp_buff xdp;
4903 		u32 act;
4904 		int err;
4905 
4906 		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4907 		if (act != XDP_PASS) {
4908 			switch (act) {
4909 			case XDP_REDIRECT:
4910 				err = xdp_do_generic_redirect(skb->dev, skb,
4911 							      &xdp, xdp_prog);
4912 				if (err)
4913 					goto out_redir;
4914 				break;
4915 			case XDP_TX:
4916 				generic_xdp_tx(skb, xdp_prog);
4917 				break;
4918 			}
4919 			return XDP_DROP;
4920 		}
4921 	}
4922 	return XDP_PASS;
4923 out_redir:
4924 	kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
4925 	return XDP_DROP;
4926 }
4927 EXPORT_SYMBOL_GPL(do_xdp_generic);
4928 
4929 static int netif_rx_internal(struct sk_buff *skb)
4930 {
4931 	int ret;
4932 
4933 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
4934 
4935 	trace_netif_rx(skb);
4936 
4937 #ifdef CONFIG_RPS
4938 	if (static_branch_unlikely(&rps_needed)) {
4939 		struct rps_dev_flow voidflow, *rflow = &voidflow;
4940 		int cpu;
4941 
4942 		rcu_read_lock();
4943 
4944 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
4945 		if (cpu < 0)
4946 			cpu = smp_processor_id();
4947 
4948 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4949 
4950 		rcu_read_unlock();
4951 	} else
4952 #endif
4953 	{
4954 		unsigned int qtail;
4955 
4956 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
4957 	}
4958 	return ret;
4959 }
4960 
4961 /**
4962  *	__netif_rx	-	Slightly optimized version of netif_rx
4963  *	@skb: buffer to post
4964  *
4965  *	This behaves as netif_rx except that it does not disable bottom halves.
4966  *	As a result this function may only be invoked from the interrupt context
4967  *	(either hard or soft interrupt).
4968  */
4969 int __netif_rx(struct sk_buff *skb)
4970 {
4971 	int ret;
4972 
4973 	lockdep_assert_once(hardirq_count() | softirq_count());
4974 
4975 	trace_netif_rx_entry(skb);
4976 	ret = netif_rx_internal(skb);
4977 	trace_netif_rx_exit(ret);
4978 	return ret;
4979 }
4980 EXPORT_SYMBOL(__netif_rx);
4981 
4982 /**
4983  *	netif_rx	-	post buffer to the network code
4984  *	@skb: buffer to post
4985  *
4986  *	This function receives a packet from a device driver and queues it for
4987  *	the upper (protocol) levels to process via the backlog NAPI device. It
4988  *	always succeeds. The buffer may be dropped during processing for
4989  *	congestion control or by the protocol layers.
4990  *	The network buffer is passed via the backlog NAPI device. Modern NIC
4991  *	driver should use NAPI and GRO.
4992  *	This function can used from interrupt and from process context. The
4993  *	caller from process context must not disable interrupts before invoking
4994  *	this function.
4995  *
4996  *	return values:
4997  *	NET_RX_SUCCESS	(no congestion)
4998  *	NET_RX_DROP     (packet was dropped)
4999  *
5000  */
5001 int netif_rx(struct sk_buff *skb)
5002 {
5003 	bool need_bh_off = !(hardirq_count() | softirq_count());
5004 	int ret;
5005 
5006 	if (need_bh_off)
5007 		local_bh_disable();
5008 	trace_netif_rx_entry(skb);
5009 	ret = netif_rx_internal(skb);
5010 	trace_netif_rx_exit(ret);
5011 	if (need_bh_off)
5012 		local_bh_enable();
5013 	return ret;
5014 }
5015 EXPORT_SYMBOL(netif_rx);
5016 
5017 static __latent_entropy void net_tx_action(struct softirq_action *h)
5018 {
5019 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5020 
5021 	if (sd->completion_queue) {
5022 		struct sk_buff *clist;
5023 
5024 		local_irq_disable();
5025 		clist = sd->completion_queue;
5026 		sd->completion_queue = NULL;
5027 		local_irq_enable();
5028 
5029 		while (clist) {
5030 			struct sk_buff *skb = clist;
5031 
5032 			clist = clist->next;
5033 
5034 			WARN_ON(refcount_read(&skb->users));
5035 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
5036 				trace_consume_skb(skb, net_tx_action);
5037 			else
5038 				trace_kfree_skb(skb, net_tx_action,
5039 						get_kfree_skb_cb(skb)->reason);
5040 
5041 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5042 				__kfree_skb(skb);
5043 			else
5044 				__kfree_skb_defer(skb);
5045 		}
5046 	}
5047 
5048 	if (sd->output_queue) {
5049 		struct Qdisc *head;
5050 
5051 		local_irq_disable();
5052 		head = sd->output_queue;
5053 		sd->output_queue = NULL;
5054 		sd->output_queue_tailp = &sd->output_queue;
5055 		local_irq_enable();
5056 
5057 		rcu_read_lock();
5058 
5059 		while (head) {
5060 			struct Qdisc *q = head;
5061 			spinlock_t *root_lock = NULL;
5062 
5063 			head = head->next_sched;
5064 
5065 			/* We need to make sure head->next_sched is read
5066 			 * before clearing __QDISC_STATE_SCHED
5067 			 */
5068 			smp_mb__before_atomic();
5069 
5070 			if (!(q->flags & TCQ_F_NOLOCK)) {
5071 				root_lock = qdisc_lock(q);
5072 				spin_lock(root_lock);
5073 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5074 						     &q->state))) {
5075 				/* There is a synchronize_net() between
5076 				 * STATE_DEACTIVATED flag being set and
5077 				 * qdisc_reset()/some_qdisc_is_busy() in
5078 				 * dev_deactivate(), so we can safely bail out
5079 				 * early here to avoid data race between
5080 				 * qdisc_deactivate() and some_qdisc_is_busy()
5081 				 * for lockless qdisc.
5082 				 */
5083 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5084 				continue;
5085 			}
5086 
5087 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5088 			qdisc_run(q);
5089 			if (root_lock)
5090 				spin_unlock(root_lock);
5091 		}
5092 
5093 		rcu_read_unlock();
5094 	}
5095 
5096 	xfrm_dev_backlog(sd);
5097 }
5098 
5099 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5100 /* This hook is defined here for ATM LANE */
5101 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5102 			     unsigned char *addr) __read_mostly;
5103 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5104 #endif
5105 
5106 static inline struct sk_buff *
5107 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5108 		   struct net_device *orig_dev, bool *another)
5109 {
5110 #ifdef CONFIG_NET_CLS_ACT
5111 	struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5112 	struct tcf_result cl_res;
5113 
5114 	/* If there's at least one ingress present somewhere (so
5115 	 * we get here via enabled static key), remaining devices
5116 	 * that are not configured with an ingress qdisc will bail
5117 	 * out here.
5118 	 */
5119 	if (!miniq)
5120 		return skb;
5121 
5122 	if (*pt_prev) {
5123 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
5124 		*pt_prev = NULL;
5125 	}
5126 
5127 	qdisc_skb_cb(skb)->pkt_len = skb->len;
5128 	tc_skb_cb(skb)->mru = 0;
5129 	tc_skb_cb(skb)->post_ct = false;
5130 	skb->tc_at_ingress = 1;
5131 	mini_qdisc_bstats_cpu_update(miniq, skb);
5132 
5133 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5134 	case TC_ACT_OK:
5135 	case TC_ACT_RECLASSIFY:
5136 		skb->tc_index = TC_H_MIN(cl_res.classid);
5137 		break;
5138 	case TC_ACT_SHOT:
5139 		mini_qdisc_qstats_cpu_drop(miniq);
5140 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
5141 		*ret = NET_RX_DROP;
5142 		return NULL;
5143 	case TC_ACT_STOLEN:
5144 	case TC_ACT_QUEUED:
5145 	case TC_ACT_TRAP:
5146 		consume_skb(skb);
5147 		*ret = NET_RX_SUCCESS;
5148 		return NULL;
5149 	case TC_ACT_REDIRECT:
5150 		/* skb_mac_header check was done by cls/act_bpf, so
5151 		 * we can safely push the L2 header back before
5152 		 * redirecting to another netdev
5153 		 */
5154 		__skb_push(skb, skb->mac_len);
5155 		if (skb_do_redirect(skb) == -EAGAIN) {
5156 			__skb_pull(skb, skb->mac_len);
5157 			*another = true;
5158 			break;
5159 		}
5160 		*ret = NET_RX_SUCCESS;
5161 		return NULL;
5162 	case TC_ACT_CONSUMED:
5163 		*ret = NET_RX_SUCCESS;
5164 		return NULL;
5165 	default:
5166 		break;
5167 	}
5168 #endif /* CONFIG_NET_CLS_ACT */
5169 	return skb;
5170 }
5171 
5172 /**
5173  *	netdev_is_rx_handler_busy - check if receive handler is registered
5174  *	@dev: device to check
5175  *
5176  *	Check if a receive handler is already registered for a given device.
5177  *	Return true if there one.
5178  *
5179  *	The caller must hold the rtnl_mutex.
5180  */
5181 bool netdev_is_rx_handler_busy(struct net_device *dev)
5182 {
5183 	ASSERT_RTNL();
5184 	return dev && rtnl_dereference(dev->rx_handler);
5185 }
5186 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5187 
5188 /**
5189  *	netdev_rx_handler_register - register receive handler
5190  *	@dev: device to register a handler for
5191  *	@rx_handler: receive handler to register
5192  *	@rx_handler_data: data pointer that is used by rx handler
5193  *
5194  *	Register a receive handler for a device. This handler will then be
5195  *	called from __netif_receive_skb. A negative errno code is returned
5196  *	on a failure.
5197  *
5198  *	The caller must hold the rtnl_mutex.
5199  *
5200  *	For a general description of rx_handler, see enum rx_handler_result.
5201  */
5202 int netdev_rx_handler_register(struct net_device *dev,
5203 			       rx_handler_func_t *rx_handler,
5204 			       void *rx_handler_data)
5205 {
5206 	if (netdev_is_rx_handler_busy(dev))
5207 		return -EBUSY;
5208 
5209 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5210 		return -EINVAL;
5211 
5212 	/* Note: rx_handler_data must be set before rx_handler */
5213 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5214 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5215 
5216 	return 0;
5217 }
5218 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5219 
5220 /**
5221  *	netdev_rx_handler_unregister - unregister receive handler
5222  *	@dev: device to unregister a handler from
5223  *
5224  *	Unregister a receive handler from a device.
5225  *
5226  *	The caller must hold the rtnl_mutex.
5227  */
5228 void netdev_rx_handler_unregister(struct net_device *dev)
5229 {
5230 
5231 	ASSERT_RTNL();
5232 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5233 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5234 	 * section has a guarantee to see a non NULL rx_handler_data
5235 	 * as well.
5236 	 */
5237 	synchronize_net();
5238 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5239 }
5240 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5241 
5242 /*
5243  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5244  * the special handling of PFMEMALLOC skbs.
5245  */
5246 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5247 {
5248 	switch (skb->protocol) {
5249 	case htons(ETH_P_ARP):
5250 	case htons(ETH_P_IP):
5251 	case htons(ETH_P_IPV6):
5252 	case htons(ETH_P_8021Q):
5253 	case htons(ETH_P_8021AD):
5254 		return true;
5255 	default:
5256 		return false;
5257 	}
5258 }
5259 
5260 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5261 			     int *ret, struct net_device *orig_dev)
5262 {
5263 	if (nf_hook_ingress_active(skb)) {
5264 		int ingress_retval;
5265 
5266 		if (*pt_prev) {
5267 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5268 			*pt_prev = NULL;
5269 		}
5270 
5271 		rcu_read_lock();
5272 		ingress_retval = nf_hook_ingress(skb);
5273 		rcu_read_unlock();
5274 		return ingress_retval;
5275 	}
5276 	return 0;
5277 }
5278 
5279 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5280 				    struct packet_type **ppt_prev)
5281 {
5282 	struct packet_type *ptype, *pt_prev;
5283 	rx_handler_func_t *rx_handler;
5284 	struct sk_buff *skb = *pskb;
5285 	struct net_device *orig_dev;
5286 	bool deliver_exact = false;
5287 	int ret = NET_RX_DROP;
5288 	__be16 type;
5289 
5290 	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5291 
5292 	trace_netif_receive_skb(skb);
5293 
5294 	orig_dev = skb->dev;
5295 
5296 	skb_reset_network_header(skb);
5297 	if (!skb_transport_header_was_set(skb))
5298 		skb_reset_transport_header(skb);
5299 	skb_reset_mac_len(skb);
5300 
5301 	pt_prev = NULL;
5302 
5303 another_round:
5304 	skb->skb_iif = skb->dev->ifindex;
5305 
5306 	__this_cpu_inc(softnet_data.processed);
5307 
5308 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5309 		int ret2;
5310 
5311 		migrate_disable();
5312 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5313 		migrate_enable();
5314 
5315 		if (ret2 != XDP_PASS) {
5316 			ret = NET_RX_DROP;
5317 			goto out;
5318 		}
5319 	}
5320 
5321 	if (eth_type_vlan(skb->protocol)) {
5322 		skb = skb_vlan_untag(skb);
5323 		if (unlikely(!skb))
5324 			goto out;
5325 	}
5326 
5327 	if (skb_skip_tc_classify(skb))
5328 		goto skip_classify;
5329 
5330 	if (pfmemalloc)
5331 		goto skip_taps;
5332 
5333 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
5334 		if (pt_prev)
5335 			ret = deliver_skb(skb, pt_prev, orig_dev);
5336 		pt_prev = ptype;
5337 	}
5338 
5339 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5340 		if (pt_prev)
5341 			ret = deliver_skb(skb, pt_prev, orig_dev);
5342 		pt_prev = ptype;
5343 	}
5344 
5345 skip_taps:
5346 #ifdef CONFIG_NET_INGRESS
5347 	if (static_branch_unlikely(&ingress_needed_key)) {
5348 		bool another = false;
5349 
5350 		nf_skip_egress(skb, true);
5351 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5352 					 &another);
5353 		if (another)
5354 			goto another_round;
5355 		if (!skb)
5356 			goto out;
5357 
5358 		nf_skip_egress(skb, false);
5359 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5360 			goto out;
5361 	}
5362 #endif
5363 	skb_reset_redirect(skb);
5364 skip_classify:
5365 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5366 		goto drop;
5367 
5368 	if (skb_vlan_tag_present(skb)) {
5369 		if (pt_prev) {
5370 			ret = deliver_skb(skb, pt_prev, orig_dev);
5371 			pt_prev = NULL;
5372 		}
5373 		if (vlan_do_receive(&skb))
5374 			goto another_round;
5375 		else if (unlikely(!skb))
5376 			goto out;
5377 	}
5378 
5379 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5380 	if (rx_handler) {
5381 		if (pt_prev) {
5382 			ret = deliver_skb(skb, pt_prev, orig_dev);
5383 			pt_prev = NULL;
5384 		}
5385 		switch (rx_handler(&skb)) {
5386 		case RX_HANDLER_CONSUMED:
5387 			ret = NET_RX_SUCCESS;
5388 			goto out;
5389 		case RX_HANDLER_ANOTHER:
5390 			goto another_round;
5391 		case RX_HANDLER_EXACT:
5392 			deliver_exact = true;
5393 			break;
5394 		case RX_HANDLER_PASS:
5395 			break;
5396 		default:
5397 			BUG();
5398 		}
5399 	}
5400 
5401 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5402 check_vlan_id:
5403 		if (skb_vlan_tag_get_id(skb)) {
5404 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5405 			 * find vlan device.
5406 			 */
5407 			skb->pkt_type = PACKET_OTHERHOST;
5408 		} else if (eth_type_vlan(skb->protocol)) {
5409 			/* Outer header is 802.1P with vlan 0, inner header is
5410 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5411 			 * not find vlan dev for vlan id 0.
5412 			 */
5413 			__vlan_hwaccel_clear_tag(skb);
5414 			skb = skb_vlan_untag(skb);
5415 			if (unlikely(!skb))
5416 				goto out;
5417 			if (vlan_do_receive(&skb))
5418 				/* After stripping off 802.1P header with vlan 0
5419 				 * vlan dev is found for inner header.
5420 				 */
5421 				goto another_round;
5422 			else if (unlikely(!skb))
5423 				goto out;
5424 			else
5425 				/* We have stripped outer 802.1P vlan 0 header.
5426 				 * But could not find vlan dev.
5427 				 * check again for vlan id to set OTHERHOST.
5428 				 */
5429 				goto check_vlan_id;
5430 		}
5431 		/* Note: we might in the future use prio bits
5432 		 * and set skb->priority like in vlan_do_receive()
5433 		 * For the time being, just ignore Priority Code Point
5434 		 */
5435 		__vlan_hwaccel_clear_tag(skb);
5436 	}
5437 
5438 	type = skb->protocol;
5439 
5440 	/* deliver only exact match when indicated */
5441 	if (likely(!deliver_exact)) {
5442 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5443 				       &ptype_base[ntohs(type) &
5444 						   PTYPE_HASH_MASK]);
5445 	}
5446 
5447 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5448 			       &orig_dev->ptype_specific);
5449 
5450 	if (unlikely(skb->dev != orig_dev)) {
5451 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5452 				       &skb->dev->ptype_specific);
5453 	}
5454 
5455 	if (pt_prev) {
5456 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5457 			goto drop;
5458 		*ppt_prev = pt_prev;
5459 	} else {
5460 drop:
5461 		if (!deliver_exact)
5462 			dev_core_stats_rx_dropped_inc(skb->dev);
5463 		else
5464 			dev_core_stats_rx_nohandler_inc(skb->dev);
5465 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5466 		/* Jamal, now you will not able to escape explaining
5467 		 * me how you were going to use this. :-)
5468 		 */
5469 		ret = NET_RX_DROP;
5470 	}
5471 
5472 out:
5473 	/* The invariant here is that if *ppt_prev is not NULL
5474 	 * then skb should also be non-NULL.
5475 	 *
5476 	 * Apparently *ppt_prev assignment above holds this invariant due to
5477 	 * skb dereferencing near it.
5478 	 */
5479 	*pskb = skb;
5480 	return ret;
5481 }
5482 
5483 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5484 {
5485 	struct net_device *orig_dev = skb->dev;
5486 	struct packet_type *pt_prev = NULL;
5487 	int ret;
5488 
5489 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5490 	if (pt_prev)
5491 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5492 					 skb->dev, pt_prev, orig_dev);
5493 	return ret;
5494 }
5495 
5496 /**
5497  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5498  *	@skb: buffer to process
5499  *
5500  *	More direct receive version of netif_receive_skb().  It should
5501  *	only be used by callers that have a need to skip RPS and Generic XDP.
5502  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5503  *
5504  *	This function may only be called from softirq context and interrupts
5505  *	should be enabled.
5506  *
5507  *	Return values (usually ignored):
5508  *	NET_RX_SUCCESS: no congestion
5509  *	NET_RX_DROP: packet was dropped
5510  */
5511 int netif_receive_skb_core(struct sk_buff *skb)
5512 {
5513 	int ret;
5514 
5515 	rcu_read_lock();
5516 	ret = __netif_receive_skb_one_core(skb, false);
5517 	rcu_read_unlock();
5518 
5519 	return ret;
5520 }
5521 EXPORT_SYMBOL(netif_receive_skb_core);
5522 
5523 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5524 						  struct packet_type *pt_prev,
5525 						  struct net_device *orig_dev)
5526 {
5527 	struct sk_buff *skb, *next;
5528 
5529 	if (!pt_prev)
5530 		return;
5531 	if (list_empty(head))
5532 		return;
5533 	if (pt_prev->list_func != NULL)
5534 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5535 				   ip_list_rcv, head, pt_prev, orig_dev);
5536 	else
5537 		list_for_each_entry_safe(skb, next, head, list) {
5538 			skb_list_del_init(skb);
5539 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5540 		}
5541 }
5542 
5543 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5544 {
5545 	/* Fast-path assumptions:
5546 	 * - There is no RX handler.
5547 	 * - Only one packet_type matches.
5548 	 * If either of these fails, we will end up doing some per-packet
5549 	 * processing in-line, then handling the 'last ptype' for the whole
5550 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5551 	 * because the 'last ptype' must be constant across the sublist, and all
5552 	 * other ptypes are handled per-packet.
5553 	 */
5554 	/* Current (common) ptype of sublist */
5555 	struct packet_type *pt_curr = NULL;
5556 	/* Current (common) orig_dev of sublist */
5557 	struct net_device *od_curr = NULL;
5558 	struct list_head sublist;
5559 	struct sk_buff *skb, *next;
5560 
5561 	INIT_LIST_HEAD(&sublist);
5562 	list_for_each_entry_safe(skb, next, head, list) {
5563 		struct net_device *orig_dev = skb->dev;
5564 		struct packet_type *pt_prev = NULL;
5565 
5566 		skb_list_del_init(skb);
5567 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5568 		if (!pt_prev)
5569 			continue;
5570 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5571 			/* dispatch old sublist */
5572 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5573 			/* start new sublist */
5574 			INIT_LIST_HEAD(&sublist);
5575 			pt_curr = pt_prev;
5576 			od_curr = orig_dev;
5577 		}
5578 		list_add_tail(&skb->list, &sublist);
5579 	}
5580 
5581 	/* dispatch final sublist */
5582 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5583 }
5584 
5585 static int __netif_receive_skb(struct sk_buff *skb)
5586 {
5587 	int ret;
5588 
5589 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5590 		unsigned int noreclaim_flag;
5591 
5592 		/*
5593 		 * PFMEMALLOC skbs are special, they should
5594 		 * - be delivered to SOCK_MEMALLOC sockets only
5595 		 * - stay away from userspace
5596 		 * - have bounded memory usage
5597 		 *
5598 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5599 		 * context down to all allocation sites.
5600 		 */
5601 		noreclaim_flag = memalloc_noreclaim_save();
5602 		ret = __netif_receive_skb_one_core(skb, true);
5603 		memalloc_noreclaim_restore(noreclaim_flag);
5604 	} else
5605 		ret = __netif_receive_skb_one_core(skb, false);
5606 
5607 	return ret;
5608 }
5609 
5610 static void __netif_receive_skb_list(struct list_head *head)
5611 {
5612 	unsigned long noreclaim_flag = 0;
5613 	struct sk_buff *skb, *next;
5614 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5615 
5616 	list_for_each_entry_safe(skb, next, head, list) {
5617 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5618 			struct list_head sublist;
5619 
5620 			/* Handle the previous sublist */
5621 			list_cut_before(&sublist, head, &skb->list);
5622 			if (!list_empty(&sublist))
5623 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5624 			pfmemalloc = !pfmemalloc;
5625 			/* See comments in __netif_receive_skb */
5626 			if (pfmemalloc)
5627 				noreclaim_flag = memalloc_noreclaim_save();
5628 			else
5629 				memalloc_noreclaim_restore(noreclaim_flag);
5630 		}
5631 	}
5632 	/* Handle the remaining sublist */
5633 	if (!list_empty(head))
5634 		__netif_receive_skb_list_core(head, pfmemalloc);
5635 	/* Restore pflags */
5636 	if (pfmemalloc)
5637 		memalloc_noreclaim_restore(noreclaim_flag);
5638 }
5639 
5640 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5641 {
5642 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5643 	struct bpf_prog *new = xdp->prog;
5644 	int ret = 0;
5645 
5646 	switch (xdp->command) {
5647 	case XDP_SETUP_PROG:
5648 		rcu_assign_pointer(dev->xdp_prog, new);
5649 		if (old)
5650 			bpf_prog_put(old);
5651 
5652 		if (old && !new) {
5653 			static_branch_dec(&generic_xdp_needed_key);
5654 		} else if (new && !old) {
5655 			static_branch_inc(&generic_xdp_needed_key);
5656 			dev_disable_lro(dev);
5657 			dev_disable_gro_hw(dev);
5658 		}
5659 		break;
5660 
5661 	default:
5662 		ret = -EINVAL;
5663 		break;
5664 	}
5665 
5666 	return ret;
5667 }
5668 
5669 static int netif_receive_skb_internal(struct sk_buff *skb)
5670 {
5671 	int ret;
5672 
5673 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5674 
5675 	if (skb_defer_rx_timestamp(skb))
5676 		return NET_RX_SUCCESS;
5677 
5678 	rcu_read_lock();
5679 #ifdef CONFIG_RPS
5680 	if (static_branch_unlikely(&rps_needed)) {
5681 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5682 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5683 
5684 		if (cpu >= 0) {
5685 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5686 			rcu_read_unlock();
5687 			return ret;
5688 		}
5689 	}
5690 #endif
5691 	ret = __netif_receive_skb(skb);
5692 	rcu_read_unlock();
5693 	return ret;
5694 }
5695 
5696 void netif_receive_skb_list_internal(struct list_head *head)
5697 {
5698 	struct sk_buff *skb, *next;
5699 	struct list_head sublist;
5700 
5701 	INIT_LIST_HEAD(&sublist);
5702 	list_for_each_entry_safe(skb, next, head, list) {
5703 		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5704 		skb_list_del_init(skb);
5705 		if (!skb_defer_rx_timestamp(skb))
5706 			list_add_tail(&skb->list, &sublist);
5707 	}
5708 	list_splice_init(&sublist, head);
5709 
5710 	rcu_read_lock();
5711 #ifdef CONFIG_RPS
5712 	if (static_branch_unlikely(&rps_needed)) {
5713 		list_for_each_entry_safe(skb, next, head, list) {
5714 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5715 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5716 
5717 			if (cpu >= 0) {
5718 				/* Will be handled, remove from list */
5719 				skb_list_del_init(skb);
5720 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5721 			}
5722 		}
5723 	}
5724 #endif
5725 	__netif_receive_skb_list(head);
5726 	rcu_read_unlock();
5727 }
5728 
5729 /**
5730  *	netif_receive_skb - process receive buffer from network
5731  *	@skb: buffer to process
5732  *
5733  *	netif_receive_skb() is the main receive data processing function.
5734  *	It always succeeds. The buffer may be dropped during processing
5735  *	for congestion control or by the protocol layers.
5736  *
5737  *	This function may only be called from softirq context and interrupts
5738  *	should be enabled.
5739  *
5740  *	Return values (usually ignored):
5741  *	NET_RX_SUCCESS: no congestion
5742  *	NET_RX_DROP: packet was dropped
5743  */
5744 int netif_receive_skb(struct sk_buff *skb)
5745 {
5746 	int ret;
5747 
5748 	trace_netif_receive_skb_entry(skb);
5749 
5750 	ret = netif_receive_skb_internal(skb);
5751 	trace_netif_receive_skb_exit(ret);
5752 
5753 	return ret;
5754 }
5755 EXPORT_SYMBOL(netif_receive_skb);
5756 
5757 /**
5758  *	netif_receive_skb_list - process many receive buffers from network
5759  *	@head: list of skbs to process.
5760  *
5761  *	Since return value of netif_receive_skb() is normally ignored, and
5762  *	wouldn't be meaningful for a list, this function returns void.
5763  *
5764  *	This function may only be called from softirq context and interrupts
5765  *	should be enabled.
5766  */
5767 void netif_receive_skb_list(struct list_head *head)
5768 {
5769 	struct sk_buff *skb;
5770 
5771 	if (list_empty(head))
5772 		return;
5773 	if (trace_netif_receive_skb_list_entry_enabled()) {
5774 		list_for_each_entry(skb, head, list)
5775 			trace_netif_receive_skb_list_entry(skb);
5776 	}
5777 	netif_receive_skb_list_internal(head);
5778 	trace_netif_receive_skb_list_exit(0);
5779 }
5780 EXPORT_SYMBOL(netif_receive_skb_list);
5781 
5782 static DEFINE_PER_CPU(struct work_struct, flush_works);
5783 
5784 /* Network device is going away, flush any packets still pending */
5785 static void flush_backlog(struct work_struct *work)
5786 {
5787 	struct sk_buff *skb, *tmp;
5788 	struct softnet_data *sd;
5789 
5790 	local_bh_disable();
5791 	sd = this_cpu_ptr(&softnet_data);
5792 
5793 	rps_lock_irq_disable(sd);
5794 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5795 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5796 			__skb_unlink(skb, &sd->input_pkt_queue);
5797 			dev_kfree_skb_irq(skb);
5798 			input_queue_head_incr(sd);
5799 		}
5800 	}
5801 	rps_unlock_irq_enable(sd);
5802 
5803 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5804 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5805 			__skb_unlink(skb, &sd->process_queue);
5806 			kfree_skb(skb);
5807 			input_queue_head_incr(sd);
5808 		}
5809 	}
5810 	local_bh_enable();
5811 }
5812 
5813 static bool flush_required(int cpu)
5814 {
5815 #if IS_ENABLED(CONFIG_RPS)
5816 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5817 	bool do_flush;
5818 
5819 	rps_lock_irq_disable(sd);
5820 
5821 	/* as insertion into process_queue happens with the rps lock held,
5822 	 * process_queue access may race only with dequeue
5823 	 */
5824 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5825 		   !skb_queue_empty_lockless(&sd->process_queue);
5826 	rps_unlock_irq_enable(sd);
5827 
5828 	return do_flush;
5829 #endif
5830 	/* without RPS we can't safely check input_pkt_queue: during a
5831 	 * concurrent remote skb_queue_splice() we can detect as empty both
5832 	 * input_pkt_queue and process_queue even if the latter could end-up
5833 	 * containing a lot of packets.
5834 	 */
5835 	return true;
5836 }
5837 
5838 static void flush_all_backlogs(void)
5839 {
5840 	static cpumask_t flush_cpus;
5841 	unsigned int cpu;
5842 
5843 	/* since we are under rtnl lock protection we can use static data
5844 	 * for the cpumask and avoid allocating on stack the possibly
5845 	 * large mask
5846 	 */
5847 	ASSERT_RTNL();
5848 
5849 	cpus_read_lock();
5850 
5851 	cpumask_clear(&flush_cpus);
5852 	for_each_online_cpu(cpu) {
5853 		if (flush_required(cpu)) {
5854 			queue_work_on(cpu, system_highpri_wq,
5855 				      per_cpu_ptr(&flush_works, cpu));
5856 			cpumask_set_cpu(cpu, &flush_cpus);
5857 		}
5858 	}
5859 
5860 	/* we can have in flight packet[s] on the cpus we are not flushing,
5861 	 * synchronize_net() in unregister_netdevice_many() will take care of
5862 	 * them
5863 	 */
5864 	for_each_cpu(cpu, &flush_cpus)
5865 		flush_work(per_cpu_ptr(&flush_works, cpu));
5866 
5867 	cpus_read_unlock();
5868 }
5869 
5870 static void net_rps_send_ipi(struct softnet_data *remsd)
5871 {
5872 #ifdef CONFIG_RPS
5873 	while (remsd) {
5874 		struct softnet_data *next = remsd->rps_ipi_next;
5875 
5876 		if (cpu_online(remsd->cpu))
5877 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
5878 		remsd = next;
5879 	}
5880 #endif
5881 }
5882 
5883 /*
5884  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5885  * Note: called with local irq disabled, but exits with local irq enabled.
5886  */
5887 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5888 {
5889 #ifdef CONFIG_RPS
5890 	struct softnet_data *remsd = sd->rps_ipi_list;
5891 
5892 	if (remsd) {
5893 		sd->rps_ipi_list = NULL;
5894 
5895 		local_irq_enable();
5896 
5897 		/* Send pending IPI's to kick RPS processing on remote cpus. */
5898 		net_rps_send_ipi(remsd);
5899 	} else
5900 #endif
5901 		local_irq_enable();
5902 }
5903 
5904 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5905 {
5906 #ifdef CONFIG_RPS
5907 	return sd->rps_ipi_list != NULL;
5908 #else
5909 	return false;
5910 #endif
5911 }
5912 
5913 static int process_backlog(struct napi_struct *napi, int quota)
5914 {
5915 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5916 	bool again = true;
5917 	int work = 0;
5918 
5919 	/* Check if we have pending ipi, its better to send them now,
5920 	 * not waiting net_rx_action() end.
5921 	 */
5922 	if (sd_has_rps_ipi_waiting(sd)) {
5923 		local_irq_disable();
5924 		net_rps_action_and_irq_enable(sd);
5925 	}
5926 
5927 	napi->weight = READ_ONCE(dev_rx_weight);
5928 	while (again) {
5929 		struct sk_buff *skb;
5930 
5931 		while ((skb = __skb_dequeue(&sd->process_queue))) {
5932 			rcu_read_lock();
5933 			__netif_receive_skb(skb);
5934 			rcu_read_unlock();
5935 			input_queue_head_incr(sd);
5936 			if (++work >= quota)
5937 				return work;
5938 
5939 		}
5940 
5941 		rps_lock_irq_disable(sd);
5942 		if (skb_queue_empty(&sd->input_pkt_queue)) {
5943 			/*
5944 			 * Inline a custom version of __napi_complete().
5945 			 * only current cpu owns and manipulates this napi,
5946 			 * and NAPI_STATE_SCHED is the only possible flag set
5947 			 * on backlog.
5948 			 * We can use a plain write instead of clear_bit(),
5949 			 * and we dont need an smp_mb() memory barrier.
5950 			 */
5951 			napi->state = 0;
5952 			again = false;
5953 		} else {
5954 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
5955 						   &sd->process_queue);
5956 		}
5957 		rps_unlock_irq_enable(sd);
5958 	}
5959 
5960 	return work;
5961 }
5962 
5963 /**
5964  * __napi_schedule - schedule for receive
5965  * @n: entry to schedule
5966  *
5967  * The entry's receive function will be scheduled to run.
5968  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5969  */
5970 void __napi_schedule(struct napi_struct *n)
5971 {
5972 	unsigned long flags;
5973 
5974 	local_irq_save(flags);
5975 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
5976 	local_irq_restore(flags);
5977 }
5978 EXPORT_SYMBOL(__napi_schedule);
5979 
5980 /**
5981  *	napi_schedule_prep - check if napi can be scheduled
5982  *	@n: napi context
5983  *
5984  * Test if NAPI routine is already running, and if not mark
5985  * it as running.  This is used as a condition variable to
5986  * insure only one NAPI poll instance runs.  We also make
5987  * sure there is no pending NAPI disable.
5988  */
5989 bool napi_schedule_prep(struct napi_struct *n)
5990 {
5991 	unsigned long new, val = READ_ONCE(n->state);
5992 
5993 	do {
5994 		if (unlikely(val & NAPIF_STATE_DISABLE))
5995 			return false;
5996 		new = val | NAPIF_STATE_SCHED;
5997 
5998 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
5999 		 * This was suggested by Alexander Duyck, as compiler
6000 		 * emits better code than :
6001 		 * if (val & NAPIF_STATE_SCHED)
6002 		 *     new |= NAPIF_STATE_MISSED;
6003 		 */
6004 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6005 						   NAPIF_STATE_MISSED;
6006 	} while (!try_cmpxchg(&n->state, &val, new));
6007 
6008 	return !(val & NAPIF_STATE_SCHED);
6009 }
6010 EXPORT_SYMBOL(napi_schedule_prep);
6011 
6012 /**
6013  * __napi_schedule_irqoff - schedule for receive
6014  * @n: entry to schedule
6015  *
6016  * Variant of __napi_schedule() assuming hard irqs are masked.
6017  *
6018  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6019  * because the interrupt disabled assumption might not be true
6020  * due to force-threaded interrupts and spinlock substitution.
6021  */
6022 void __napi_schedule_irqoff(struct napi_struct *n)
6023 {
6024 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6025 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6026 	else
6027 		__napi_schedule(n);
6028 }
6029 EXPORT_SYMBOL(__napi_schedule_irqoff);
6030 
6031 bool napi_complete_done(struct napi_struct *n, int work_done)
6032 {
6033 	unsigned long flags, val, new, timeout = 0;
6034 	bool ret = true;
6035 
6036 	/*
6037 	 * 1) Don't let napi dequeue from the cpu poll list
6038 	 *    just in case its running on a different cpu.
6039 	 * 2) If we are busy polling, do nothing here, we have
6040 	 *    the guarantee we will be called later.
6041 	 */
6042 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6043 				 NAPIF_STATE_IN_BUSY_POLL)))
6044 		return false;
6045 
6046 	if (work_done) {
6047 		if (n->gro_bitmask)
6048 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6049 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6050 	}
6051 	if (n->defer_hard_irqs_count > 0) {
6052 		n->defer_hard_irqs_count--;
6053 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6054 		if (timeout)
6055 			ret = false;
6056 	}
6057 	if (n->gro_bitmask) {
6058 		/* When the NAPI instance uses a timeout and keeps postponing
6059 		 * it, we need to bound somehow the time packets are kept in
6060 		 * the GRO layer
6061 		 */
6062 		napi_gro_flush(n, !!timeout);
6063 	}
6064 
6065 	gro_normal_list(n);
6066 
6067 	if (unlikely(!list_empty(&n->poll_list))) {
6068 		/* If n->poll_list is not empty, we need to mask irqs */
6069 		local_irq_save(flags);
6070 		list_del_init(&n->poll_list);
6071 		local_irq_restore(flags);
6072 	}
6073 
6074 	val = READ_ONCE(n->state);
6075 	do {
6076 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6077 
6078 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6079 			      NAPIF_STATE_SCHED_THREADED |
6080 			      NAPIF_STATE_PREFER_BUSY_POLL);
6081 
6082 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6083 		 * because we will call napi->poll() one more time.
6084 		 * This C code was suggested by Alexander Duyck to help gcc.
6085 		 */
6086 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6087 						    NAPIF_STATE_SCHED;
6088 	} while (!try_cmpxchg(&n->state, &val, new));
6089 
6090 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6091 		__napi_schedule(n);
6092 		return false;
6093 	}
6094 
6095 	if (timeout)
6096 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6097 			      HRTIMER_MODE_REL_PINNED);
6098 	return ret;
6099 }
6100 EXPORT_SYMBOL(napi_complete_done);
6101 
6102 /* must be called under rcu_read_lock(), as we dont take a reference */
6103 static struct napi_struct *napi_by_id(unsigned int napi_id)
6104 {
6105 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6106 	struct napi_struct *napi;
6107 
6108 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6109 		if (napi->napi_id == napi_id)
6110 			return napi;
6111 
6112 	return NULL;
6113 }
6114 
6115 #if defined(CONFIG_NET_RX_BUSY_POLL)
6116 
6117 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6118 {
6119 	if (!skip_schedule) {
6120 		gro_normal_list(napi);
6121 		__napi_schedule(napi);
6122 		return;
6123 	}
6124 
6125 	if (napi->gro_bitmask) {
6126 		/* flush too old packets
6127 		 * If HZ < 1000, flush all packets.
6128 		 */
6129 		napi_gro_flush(napi, HZ >= 1000);
6130 	}
6131 
6132 	gro_normal_list(napi);
6133 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6134 }
6135 
6136 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6137 			   u16 budget)
6138 {
6139 	bool skip_schedule = false;
6140 	unsigned long timeout;
6141 	int rc;
6142 
6143 	/* Busy polling means there is a high chance device driver hard irq
6144 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6145 	 * set in napi_schedule_prep().
6146 	 * Since we are about to call napi->poll() once more, we can safely
6147 	 * clear NAPI_STATE_MISSED.
6148 	 *
6149 	 * Note: x86 could use a single "lock and ..." instruction
6150 	 * to perform these two clear_bit()
6151 	 */
6152 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6153 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6154 
6155 	local_bh_disable();
6156 
6157 	if (prefer_busy_poll) {
6158 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6159 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6160 		if (napi->defer_hard_irqs_count && timeout) {
6161 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6162 			skip_schedule = true;
6163 		}
6164 	}
6165 
6166 	/* All we really want here is to re-enable device interrupts.
6167 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6168 	 */
6169 	rc = napi->poll(napi, budget);
6170 	/* We can't gro_normal_list() here, because napi->poll() might have
6171 	 * rearmed the napi (napi_complete_done()) in which case it could
6172 	 * already be running on another CPU.
6173 	 */
6174 	trace_napi_poll(napi, rc, budget);
6175 	netpoll_poll_unlock(have_poll_lock);
6176 	if (rc == budget)
6177 		__busy_poll_stop(napi, skip_schedule);
6178 	local_bh_enable();
6179 }
6180 
6181 void napi_busy_loop(unsigned int napi_id,
6182 		    bool (*loop_end)(void *, unsigned long),
6183 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6184 {
6185 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6186 	int (*napi_poll)(struct napi_struct *napi, int budget);
6187 	void *have_poll_lock = NULL;
6188 	struct napi_struct *napi;
6189 
6190 restart:
6191 	napi_poll = NULL;
6192 
6193 	rcu_read_lock();
6194 
6195 	napi = napi_by_id(napi_id);
6196 	if (!napi)
6197 		goto out;
6198 
6199 	preempt_disable();
6200 	for (;;) {
6201 		int work = 0;
6202 
6203 		local_bh_disable();
6204 		if (!napi_poll) {
6205 			unsigned long val = READ_ONCE(napi->state);
6206 
6207 			/* If multiple threads are competing for this napi,
6208 			 * we avoid dirtying napi->state as much as we can.
6209 			 */
6210 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6211 				   NAPIF_STATE_IN_BUSY_POLL)) {
6212 				if (prefer_busy_poll)
6213 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6214 				goto count;
6215 			}
6216 			if (cmpxchg(&napi->state, val,
6217 				    val | NAPIF_STATE_IN_BUSY_POLL |
6218 					  NAPIF_STATE_SCHED) != val) {
6219 				if (prefer_busy_poll)
6220 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6221 				goto count;
6222 			}
6223 			have_poll_lock = netpoll_poll_lock(napi);
6224 			napi_poll = napi->poll;
6225 		}
6226 		work = napi_poll(napi, budget);
6227 		trace_napi_poll(napi, work, budget);
6228 		gro_normal_list(napi);
6229 count:
6230 		if (work > 0)
6231 			__NET_ADD_STATS(dev_net(napi->dev),
6232 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6233 		local_bh_enable();
6234 
6235 		if (!loop_end || loop_end(loop_end_arg, start_time))
6236 			break;
6237 
6238 		if (unlikely(need_resched())) {
6239 			if (napi_poll)
6240 				busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6241 			preempt_enable();
6242 			rcu_read_unlock();
6243 			cond_resched();
6244 			if (loop_end(loop_end_arg, start_time))
6245 				return;
6246 			goto restart;
6247 		}
6248 		cpu_relax();
6249 	}
6250 	if (napi_poll)
6251 		busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6252 	preempt_enable();
6253 out:
6254 	rcu_read_unlock();
6255 }
6256 EXPORT_SYMBOL(napi_busy_loop);
6257 
6258 #endif /* CONFIG_NET_RX_BUSY_POLL */
6259 
6260 static void napi_hash_add(struct napi_struct *napi)
6261 {
6262 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6263 		return;
6264 
6265 	spin_lock(&napi_hash_lock);
6266 
6267 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6268 	do {
6269 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6270 			napi_gen_id = MIN_NAPI_ID;
6271 	} while (napi_by_id(napi_gen_id));
6272 	napi->napi_id = napi_gen_id;
6273 
6274 	hlist_add_head_rcu(&napi->napi_hash_node,
6275 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6276 
6277 	spin_unlock(&napi_hash_lock);
6278 }
6279 
6280 /* Warning : caller is responsible to make sure rcu grace period
6281  * is respected before freeing memory containing @napi
6282  */
6283 static void napi_hash_del(struct napi_struct *napi)
6284 {
6285 	spin_lock(&napi_hash_lock);
6286 
6287 	hlist_del_init_rcu(&napi->napi_hash_node);
6288 
6289 	spin_unlock(&napi_hash_lock);
6290 }
6291 
6292 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6293 {
6294 	struct napi_struct *napi;
6295 
6296 	napi = container_of(timer, struct napi_struct, timer);
6297 
6298 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6299 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6300 	 */
6301 	if (!napi_disable_pending(napi) &&
6302 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6303 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6304 		__napi_schedule_irqoff(napi);
6305 	}
6306 
6307 	return HRTIMER_NORESTART;
6308 }
6309 
6310 static void init_gro_hash(struct napi_struct *napi)
6311 {
6312 	int i;
6313 
6314 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6315 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6316 		napi->gro_hash[i].count = 0;
6317 	}
6318 	napi->gro_bitmask = 0;
6319 }
6320 
6321 int dev_set_threaded(struct net_device *dev, bool threaded)
6322 {
6323 	struct napi_struct *napi;
6324 	int err = 0;
6325 
6326 	if (dev->threaded == threaded)
6327 		return 0;
6328 
6329 	if (threaded) {
6330 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6331 			if (!napi->thread) {
6332 				err = napi_kthread_create(napi);
6333 				if (err) {
6334 					threaded = false;
6335 					break;
6336 				}
6337 			}
6338 		}
6339 	}
6340 
6341 	dev->threaded = threaded;
6342 
6343 	/* Make sure kthread is created before THREADED bit
6344 	 * is set.
6345 	 */
6346 	smp_mb__before_atomic();
6347 
6348 	/* Setting/unsetting threaded mode on a napi might not immediately
6349 	 * take effect, if the current napi instance is actively being
6350 	 * polled. In this case, the switch between threaded mode and
6351 	 * softirq mode will happen in the next round of napi_schedule().
6352 	 * This should not cause hiccups/stalls to the live traffic.
6353 	 */
6354 	list_for_each_entry(napi, &dev->napi_list, dev_list) {
6355 		if (threaded)
6356 			set_bit(NAPI_STATE_THREADED, &napi->state);
6357 		else
6358 			clear_bit(NAPI_STATE_THREADED, &napi->state);
6359 	}
6360 
6361 	return err;
6362 }
6363 EXPORT_SYMBOL(dev_set_threaded);
6364 
6365 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6366 			   int (*poll)(struct napi_struct *, int), int weight)
6367 {
6368 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6369 		return;
6370 
6371 	INIT_LIST_HEAD(&napi->poll_list);
6372 	INIT_HLIST_NODE(&napi->napi_hash_node);
6373 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6374 	napi->timer.function = napi_watchdog;
6375 	init_gro_hash(napi);
6376 	napi->skb = NULL;
6377 	INIT_LIST_HEAD(&napi->rx_list);
6378 	napi->rx_count = 0;
6379 	napi->poll = poll;
6380 	if (weight > NAPI_POLL_WEIGHT)
6381 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6382 				weight);
6383 	napi->weight = weight;
6384 	napi->dev = dev;
6385 #ifdef CONFIG_NETPOLL
6386 	napi->poll_owner = -1;
6387 #endif
6388 	set_bit(NAPI_STATE_SCHED, &napi->state);
6389 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6390 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6391 	napi_hash_add(napi);
6392 	napi_get_frags_check(napi);
6393 	/* Create kthread for this napi if dev->threaded is set.
6394 	 * Clear dev->threaded if kthread creation failed so that
6395 	 * threaded mode will not be enabled in napi_enable().
6396 	 */
6397 	if (dev->threaded && napi_kthread_create(napi))
6398 		dev->threaded = 0;
6399 }
6400 EXPORT_SYMBOL(netif_napi_add_weight);
6401 
6402 void napi_disable(struct napi_struct *n)
6403 {
6404 	unsigned long val, new;
6405 
6406 	might_sleep();
6407 	set_bit(NAPI_STATE_DISABLE, &n->state);
6408 
6409 	val = READ_ONCE(n->state);
6410 	do {
6411 		while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6412 			usleep_range(20, 200);
6413 			val = READ_ONCE(n->state);
6414 		}
6415 
6416 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6417 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6418 	} while (!try_cmpxchg(&n->state, &val, new));
6419 
6420 	hrtimer_cancel(&n->timer);
6421 
6422 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6423 }
6424 EXPORT_SYMBOL(napi_disable);
6425 
6426 /**
6427  *	napi_enable - enable NAPI scheduling
6428  *	@n: NAPI context
6429  *
6430  * Resume NAPI from being scheduled on this context.
6431  * Must be paired with napi_disable.
6432  */
6433 void napi_enable(struct napi_struct *n)
6434 {
6435 	unsigned long new, val = READ_ONCE(n->state);
6436 
6437 	do {
6438 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6439 
6440 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6441 		if (n->dev->threaded && n->thread)
6442 			new |= NAPIF_STATE_THREADED;
6443 	} while (!try_cmpxchg(&n->state, &val, new));
6444 }
6445 EXPORT_SYMBOL(napi_enable);
6446 
6447 static void flush_gro_hash(struct napi_struct *napi)
6448 {
6449 	int i;
6450 
6451 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6452 		struct sk_buff *skb, *n;
6453 
6454 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6455 			kfree_skb(skb);
6456 		napi->gro_hash[i].count = 0;
6457 	}
6458 }
6459 
6460 /* Must be called in process context */
6461 void __netif_napi_del(struct napi_struct *napi)
6462 {
6463 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6464 		return;
6465 
6466 	napi_hash_del(napi);
6467 	list_del_rcu(&napi->dev_list);
6468 	napi_free_frags(napi);
6469 
6470 	flush_gro_hash(napi);
6471 	napi->gro_bitmask = 0;
6472 
6473 	if (napi->thread) {
6474 		kthread_stop(napi->thread);
6475 		napi->thread = NULL;
6476 	}
6477 }
6478 EXPORT_SYMBOL(__netif_napi_del);
6479 
6480 static int __napi_poll(struct napi_struct *n, bool *repoll)
6481 {
6482 	int work, weight;
6483 
6484 	weight = n->weight;
6485 
6486 	/* This NAPI_STATE_SCHED test is for avoiding a race
6487 	 * with netpoll's poll_napi().  Only the entity which
6488 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6489 	 * actually make the ->poll() call.  Therefore we avoid
6490 	 * accidentally calling ->poll() when NAPI is not scheduled.
6491 	 */
6492 	work = 0;
6493 	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6494 		work = n->poll(n, weight);
6495 		trace_napi_poll(n, work, weight);
6496 	}
6497 
6498 	if (unlikely(work > weight))
6499 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6500 				n->poll, work, weight);
6501 
6502 	if (likely(work < weight))
6503 		return work;
6504 
6505 	/* Drivers must not modify the NAPI state if they
6506 	 * consume the entire weight.  In such cases this code
6507 	 * still "owns" the NAPI instance and therefore can
6508 	 * move the instance around on the list at-will.
6509 	 */
6510 	if (unlikely(napi_disable_pending(n))) {
6511 		napi_complete(n);
6512 		return work;
6513 	}
6514 
6515 	/* The NAPI context has more processing work, but busy-polling
6516 	 * is preferred. Exit early.
6517 	 */
6518 	if (napi_prefer_busy_poll(n)) {
6519 		if (napi_complete_done(n, work)) {
6520 			/* If timeout is not set, we need to make sure
6521 			 * that the NAPI is re-scheduled.
6522 			 */
6523 			napi_schedule(n);
6524 		}
6525 		return work;
6526 	}
6527 
6528 	if (n->gro_bitmask) {
6529 		/* flush too old packets
6530 		 * If HZ < 1000, flush all packets.
6531 		 */
6532 		napi_gro_flush(n, HZ >= 1000);
6533 	}
6534 
6535 	gro_normal_list(n);
6536 
6537 	/* Some drivers may have called napi_schedule
6538 	 * prior to exhausting their budget.
6539 	 */
6540 	if (unlikely(!list_empty(&n->poll_list))) {
6541 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6542 			     n->dev ? n->dev->name : "backlog");
6543 		return work;
6544 	}
6545 
6546 	*repoll = true;
6547 
6548 	return work;
6549 }
6550 
6551 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6552 {
6553 	bool do_repoll = false;
6554 	void *have;
6555 	int work;
6556 
6557 	list_del_init(&n->poll_list);
6558 
6559 	have = netpoll_poll_lock(n);
6560 
6561 	work = __napi_poll(n, &do_repoll);
6562 
6563 	if (do_repoll)
6564 		list_add_tail(&n->poll_list, repoll);
6565 
6566 	netpoll_poll_unlock(have);
6567 
6568 	return work;
6569 }
6570 
6571 static int napi_thread_wait(struct napi_struct *napi)
6572 {
6573 	bool woken = false;
6574 
6575 	set_current_state(TASK_INTERRUPTIBLE);
6576 
6577 	while (!kthread_should_stop()) {
6578 		/* Testing SCHED_THREADED bit here to make sure the current
6579 		 * kthread owns this napi and could poll on this napi.
6580 		 * Testing SCHED bit is not enough because SCHED bit might be
6581 		 * set by some other busy poll thread or by napi_disable().
6582 		 */
6583 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6584 			WARN_ON(!list_empty(&napi->poll_list));
6585 			__set_current_state(TASK_RUNNING);
6586 			return 0;
6587 		}
6588 
6589 		schedule();
6590 		/* woken being true indicates this thread owns this napi. */
6591 		woken = true;
6592 		set_current_state(TASK_INTERRUPTIBLE);
6593 	}
6594 	__set_current_state(TASK_RUNNING);
6595 
6596 	return -1;
6597 }
6598 
6599 static int napi_threaded_poll(void *data)
6600 {
6601 	struct napi_struct *napi = data;
6602 	void *have;
6603 
6604 	while (!napi_thread_wait(napi)) {
6605 		for (;;) {
6606 			bool repoll = false;
6607 
6608 			local_bh_disable();
6609 
6610 			have = netpoll_poll_lock(napi);
6611 			__napi_poll(napi, &repoll);
6612 			netpoll_poll_unlock(have);
6613 
6614 			local_bh_enable();
6615 
6616 			if (!repoll)
6617 				break;
6618 
6619 			cond_resched();
6620 		}
6621 	}
6622 	return 0;
6623 }
6624 
6625 static void skb_defer_free_flush(struct softnet_data *sd)
6626 {
6627 	struct sk_buff *skb, *next;
6628 
6629 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6630 	if (!READ_ONCE(sd->defer_list))
6631 		return;
6632 
6633 	spin_lock_irq(&sd->defer_lock);
6634 	skb = sd->defer_list;
6635 	sd->defer_list = NULL;
6636 	sd->defer_count = 0;
6637 	spin_unlock_irq(&sd->defer_lock);
6638 
6639 	while (skb != NULL) {
6640 		next = skb->next;
6641 		napi_consume_skb(skb, 1);
6642 		skb = next;
6643 	}
6644 }
6645 
6646 static __latent_entropy void net_rx_action(struct softirq_action *h)
6647 {
6648 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6649 	unsigned long time_limit = jiffies +
6650 		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6651 	int budget = READ_ONCE(netdev_budget);
6652 	LIST_HEAD(list);
6653 	LIST_HEAD(repoll);
6654 
6655 start:
6656 	sd->in_net_rx_action = true;
6657 	local_irq_disable();
6658 	list_splice_init(&sd->poll_list, &list);
6659 	local_irq_enable();
6660 
6661 	for (;;) {
6662 		struct napi_struct *n;
6663 
6664 		skb_defer_free_flush(sd);
6665 
6666 		if (list_empty(&list)) {
6667 			if (list_empty(&repoll)) {
6668 				sd->in_net_rx_action = false;
6669 				barrier();
6670 				/* We need to check if ____napi_schedule()
6671 				 * had refilled poll_list while
6672 				 * sd->in_net_rx_action was true.
6673 				 */
6674 				if (!list_empty(&sd->poll_list))
6675 					goto start;
6676 				if (!sd_has_rps_ipi_waiting(sd))
6677 					goto end;
6678 			}
6679 			break;
6680 		}
6681 
6682 		n = list_first_entry(&list, struct napi_struct, poll_list);
6683 		budget -= napi_poll(n, &repoll);
6684 
6685 		/* If softirq window is exhausted then punt.
6686 		 * Allow this to run for 2 jiffies since which will allow
6687 		 * an average latency of 1.5/HZ.
6688 		 */
6689 		if (unlikely(budget <= 0 ||
6690 			     time_after_eq(jiffies, time_limit))) {
6691 			sd->time_squeeze++;
6692 			break;
6693 		}
6694 	}
6695 
6696 	local_irq_disable();
6697 
6698 	list_splice_tail_init(&sd->poll_list, &list);
6699 	list_splice_tail(&repoll, &list);
6700 	list_splice(&list, &sd->poll_list);
6701 	if (!list_empty(&sd->poll_list))
6702 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6703 	else
6704 		sd->in_net_rx_action = false;
6705 
6706 	net_rps_action_and_irq_enable(sd);
6707 end:;
6708 }
6709 
6710 struct netdev_adjacent {
6711 	struct net_device *dev;
6712 	netdevice_tracker dev_tracker;
6713 
6714 	/* upper master flag, there can only be one master device per list */
6715 	bool master;
6716 
6717 	/* lookup ignore flag */
6718 	bool ignore;
6719 
6720 	/* counter for the number of times this device was added to us */
6721 	u16 ref_nr;
6722 
6723 	/* private field for the users */
6724 	void *private;
6725 
6726 	struct list_head list;
6727 	struct rcu_head rcu;
6728 };
6729 
6730 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6731 						 struct list_head *adj_list)
6732 {
6733 	struct netdev_adjacent *adj;
6734 
6735 	list_for_each_entry(adj, adj_list, list) {
6736 		if (adj->dev == adj_dev)
6737 			return adj;
6738 	}
6739 	return NULL;
6740 }
6741 
6742 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6743 				    struct netdev_nested_priv *priv)
6744 {
6745 	struct net_device *dev = (struct net_device *)priv->data;
6746 
6747 	return upper_dev == dev;
6748 }
6749 
6750 /**
6751  * netdev_has_upper_dev - Check if device is linked to an upper device
6752  * @dev: device
6753  * @upper_dev: upper device to check
6754  *
6755  * Find out if a device is linked to specified upper device and return true
6756  * in case it is. Note that this checks only immediate upper device,
6757  * not through a complete stack of devices. The caller must hold the RTNL lock.
6758  */
6759 bool netdev_has_upper_dev(struct net_device *dev,
6760 			  struct net_device *upper_dev)
6761 {
6762 	struct netdev_nested_priv priv = {
6763 		.data = (void *)upper_dev,
6764 	};
6765 
6766 	ASSERT_RTNL();
6767 
6768 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6769 					     &priv);
6770 }
6771 EXPORT_SYMBOL(netdev_has_upper_dev);
6772 
6773 /**
6774  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6775  * @dev: device
6776  * @upper_dev: upper device to check
6777  *
6778  * Find out if a device is linked to specified upper device and return true
6779  * in case it is. Note that this checks the entire upper device chain.
6780  * The caller must hold rcu lock.
6781  */
6782 
6783 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6784 				  struct net_device *upper_dev)
6785 {
6786 	struct netdev_nested_priv priv = {
6787 		.data = (void *)upper_dev,
6788 	};
6789 
6790 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6791 					       &priv);
6792 }
6793 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6794 
6795 /**
6796  * netdev_has_any_upper_dev - Check if device is linked to some device
6797  * @dev: device
6798  *
6799  * Find out if a device is linked to an upper device and return true in case
6800  * it is. The caller must hold the RTNL lock.
6801  */
6802 bool netdev_has_any_upper_dev(struct net_device *dev)
6803 {
6804 	ASSERT_RTNL();
6805 
6806 	return !list_empty(&dev->adj_list.upper);
6807 }
6808 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6809 
6810 /**
6811  * netdev_master_upper_dev_get - Get master upper device
6812  * @dev: device
6813  *
6814  * Find a master upper device and return pointer to it or NULL in case
6815  * it's not there. The caller must hold the RTNL lock.
6816  */
6817 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6818 {
6819 	struct netdev_adjacent *upper;
6820 
6821 	ASSERT_RTNL();
6822 
6823 	if (list_empty(&dev->adj_list.upper))
6824 		return NULL;
6825 
6826 	upper = list_first_entry(&dev->adj_list.upper,
6827 				 struct netdev_adjacent, list);
6828 	if (likely(upper->master))
6829 		return upper->dev;
6830 	return NULL;
6831 }
6832 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6833 
6834 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6835 {
6836 	struct netdev_adjacent *upper;
6837 
6838 	ASSERT_RTNL();
6839 
6840 	if (list_empty(&dev->adj_list.upper))
6841 		return NULL;
6842 
6843 	upper = list_first_entry(&dev->adj_list.upper,
6844 				 struct netdev_adjacent, list);
6845 	if (likely(upper->master) && !upper->ignore)
6846 		return upper->dev;
6847 	return NULL;
6848 }
6849 
6850 /**
6851  * netdev_has_any_lower_dev - Check if device is linked to some device
6852  * @dev: device
6853  *
6854  * Find out if a device is linked to a lower device and return true in case
6855  * it is. The caller must hold the RTNL lock.
6856  */
6857 static bool netdev_has_any_lower_dev(struct net_device *dev)
6858 {
6859 	ASSERT_RTNL();
6860 
6861 	return !list_empty(&dev->adj_list.lower);
6862 }
6863 
6864 void *netdev_adjacent_get_private(struct list_head *adj_list)
6865 {
6866 	struct netdev_adjacent *adj;
6867 
6868 	adj = list_entry(adj_list, struct netdev_adjacent, list);
6869 
6870 	return adj->private;
6871 }
6872 EXPORT_SYMBOL(netdev_adjacent_get_private);
6873 
6874 /**
6875  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6876  * @dev: device
6877  * @iter: list_head ** of the current position
6878  *
6879  * Gets the next device from the dev's upper list, starting from iter
6880  * position. The caller must hold RCU read lock.
6881  */
6882 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6883 						 struct list_head **iter)
6884 {
6885 	struct netdev_adjacent *upper;
6886 
6887 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6888 
6889 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6890 
6891 	if (&upper->list == &dev->adj_list.upper)
6892 		return NULL;
6893 
6894 	*iter = &upper->list;
6895 
6896 	return upper->dev;
6897 }
6898 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6899 
6900 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6901 						  struct list_head **iter,
6902 						  bool *ignore)
6903 {
6904 	struct netdev_adjacent *upper;
6905 
6906 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6907 
6908 	if (&upper->list == &dev->adj_list.upper)
6909 		return NULL;
6910 
6911 	*iter = &upper->list;
6912 	*ignore = upper->ignore;
6913 
6914 	return upper->dev;
6915 }
6916 
6917 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6918 						    struct list_head **iter)
6919 {
6920 	struct netdev_adjacent *upper;
6921 
6922 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6923 
6924 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6925 
6926 	if (&upper->list == &dev->adj_list.upper)
6927 		return NULL;
6928 
6929 	*iter = &upper->list;
6930 
6931 	return upper->dev;
6932 }
6933 
6934 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6935 				       int (*fn)(struct net_device *dev,
6936 					 struct netdev_nested_priv *priv),
6937 				       struct netdev_nested_priv *priv)
6938 {
6939 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6940 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6941 	int ret, cur = 0;
6942 	bool ignore;
6943 
6944 	now = dev;
6945 	iter = &dev->adj_list.upper;
6946 
6947 	while (1) {
6948 		if (now != dev) {
6949 			ret = fn(now, priv);
6950 			if (ret)
6951 				return ret;
6952 		}
6953 
6954 		next = NULL;
6955 		while (1) {
6956 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
6957 			if (!udev)
6958 				break;
6959 			if (ignore)
6960 				continue;
6961 
6962 			next = udev;
6963 			niter = &udev->adj_list.upper;
6964 			dev_stack[cur] = now;
6965 			iter_stack[cur++] = iter;
6966 			break;
6967 		}
6968 
6969 		if (!next) {
6970 			if (!cur)
6971 				return 0;
6972 			next = dev_stack[--cur];
6973 			niter = iter_stack[cur];
6974 		}
6975 
6976 		now = next;
6977 		iter = niter;
6978 	}
6979 
6980 	return 0;
6981 }
6982 
6983 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6984 				  int (*fn)(struct net_device *dev,
6985 					    struct netdev_nested_priv *priv),
6986 				  struct netdev_nested_priv *priv)
6987 {
6988 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6989 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6990 	int ret, cur = 0;
6991 
6992 	now = dev;
6993 	iter = &dev->adj_list.upper;
6994 
6995 	while (1) {
6996 		if (now != dev) {
6997 			ret = fn(now, priv);
6998 			if (ret)
6999 				return ret;
7000 		}
7001 
7002 		next = NULL;
7003 		while (1) {
7004 			udev = netdev_next_upper_dev_rcu(now, &iter);
7005 			if (!udev)
7006 				break;
7007 
7008 			next = udev;
7009 			niter = &udev->adj_list.upper;
7010 			dev_stack[cur] = now;
7011 			iter_stack[cur++] = iter;
7012 			break;
7013 		}
7014 
7015 		if (!next) {
7016 			if (!cur)
7017 				return 0;
7018 			next = dev_stack[--cur];
7019 			niter = iter_stack[cur];
7020 		}
7021 
7022 		now = next;
7023 		iter = niter;
7024 	}
7025 
7026 	return 0;
7027 }
7028 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7029 
7030 static bool __netdev_has_upper_dev(struct net_device *dev,
7031 				   struct net_device *upper_dev)
7032 {
7033 	struct netdev_nested_priv priv = {
7034 		.flags = 0,
7035 		.data = (void *)upper_dev,
7036 	};
7037 
7038 	ASSERT_RTNL();
7039 
7040 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7041 					   &priv);
7042 }
7043 
7044 /**
7045  * netdev_lower_get_next_private - Get the next ->private from the
7046  *				   lower neighbour list
7047  * @dev: device
7048  * @iter: list_head ** of the current position
7049  *
7050  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7051  * list, starting from iter position. The caller must hold either hold the
7052  * RTNL lock or its own locking that guarantees that the neighbour lower
7053  * list will remain unchanged.
7054  */
7055 void *netdev_lower_get_next_private(struct net_device *dev,
7056 				    struct list_head **iter)
7057 {
7058 	struct netdev_adjacent *lower;
7059 
7060 	lower = list_entry(*iter, struct netdev_adjacent, list);
7061 
7062 	if (&lower->list == &dev->adj_list.lower)
7063 		return NULL;
7064 
7065 	*iter = lower->list.next;
7066 
7067 	return lower->private;
7068 }
7069 EXPORT_SYMBOL(netdev_lower_get_next_private);
7070 
7071 /**
7072  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7073  *				       lower neighbour list, RCU
7074  *				       variant
7075  * @dev: device
7076  * @iter: list_head ** of the current position
7077  *
7078  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7079  * list, starting from iter position. The caller must hold RCU read lock.
7080  */
7081 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7082 					struct list_head **iter)
7083 {
7084 	struct netdev_adjacent *lower;
7085 
7086 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7087 
7088 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7089 
7090 	if (&lower->list == &dev->adj_list.lower)
7091 		return NULL;
7092 
7093 	*iter = &lower->list;
7094 
7095 	return lower->private;
7096 }
7097 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7098 
7099 /**
7100  * netdev_lower_get_next - Get the next device from the lower neighbour
7101  *                         list
7102  * @dev: device
7103  * @iter: list_head ** of the current position
7104  *
7105  * Gets the next netdev_adjacent from the dev's lower neighbour
7106  * list, starting from iter position. The caller must hold RTNL lock or
7107  * its own locking that guarantees that the neighbour lower
7108  * list will remain unchanged.
7109  */
7110 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7111 {
7112 	struct netdev_adjacent *lower;
7113 
7114 	lower = list_entry(*iter, struct netdev_adjacent, list);
7115 
7116 	if (&lower->list == &dev->adj_list.lower)
7117 		return NULL;
7118 
7119 	*iter = lower->list.next;
7120 
7121 	return lower->dev;
7122 }
7123 EXPORT_SYMBOL(netdev_lower_get_next);
7124 
7125 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7126 						struct list_head **iter)
7127 {
7128 	struct netdev_adjacent *lower;
7129 
7130 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7131 
7132 	if (&lower->list == &dev->adj_list.lower)
7133 		return NULL;
7134 
7135 	*iter = &lower->list;
7136 
7137 	return lower->dev;
7138 }
7139 
7140 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7141 						  struct list_head **iter,
7142 						  bool *ignore)
7143 {
7144 	struct netdev_adjacent *lower;
7145 
7146 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7147 
7148 	if (&lower->list == &dev->adj_list.lower)
7149 		return NULL;
7150 
7151 	*iter = &lower->list;
7152 	*ignore = lower->ignore;
7153 
7154 	return lower->dev;
7155 }
7156 
7157 int netdev_walk_all_lower_dev(struct net_device *dev,
7158 			      int (*fn)(struct net_device *dev,
7159 					struct netdev_nested_priv *priv),
7160 			      struct netdev_nested_priv *priv)
7161 {
7162 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7163 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7164 	int ret, cur = 0;
7165 
7166 	now = dev;
7167 	iter = &dev->adj_list.lower;
7168 
7169 	while (1) {
7170 		if (now != dev) {
7171 			ret = fn(now, priv);
7172 			if (ret)
7173 				return ret;
7174 		}
7175 
7176 		next = NULL;
7177 		while (1) {
7178 			ldev = netdev_next_lower_dev(now, &iter);
7179 			if (!ldev)
7180 				break;
7181 
7182 			next = ldev;
7183 			niter = &ldev->adj_list.lower;
7184 			dev_stack[cur] = now;
7185 			iter_stack[cur++] = iter;
7186 			break;
7187 		}
7188 
7189 		if (!next) {
7190 			if (!cur)
7191 				return 0;
7192 			next = dev_stack[--cur];
7193 			niter = iter_stack[cur];
7194 		}
7195 
7196 		now = next;
7197 		iter = niter;
7198 	}
7199 
7200 	return 0;
7201 }
7202 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7203 
7204 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7205 				       int (*fn)(struct net_device *dev,
7206 					 struct netdev_nested_priv *priv),
7207 				       struct netdev_nested_priv *priv)
7208 {
7209 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7210 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7211 	int ret, cur = 0;
7212 	bool ignore;
7213 
7214 	now = dev;
7215 	iter = &dev->adj_list.lower;
7216 
7217 	while (1) {
7218 		if (now != dev) {
7219 			ret = fn(now, priv);
7220 			if (ret)
7221 				return ret;
7222 		}
7223 
7224 		next = NULL;
7225 		while (1) {
7226 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7227 			if (!ldev)
7228 				break;
7229 			if (ignore)
7230 				continue;
7231 
7232 			next = ldev;
7233 			niter = &ldev->adj_list.lower;
7234 			dev_stack[cur] = now;
7235 			iter_stack[cur++] = iter;
7236 			break;
7237 		}
7238 
7239 		if (!next) {
7240 			if (!cur)
7241 				return 0;
7242 			next = dev_stack[--cur];
7243 			niter = iter_stack[cur];
7244 		}
7245 
7246 		now = next;
7247 		iter = niter;
7248 	}
7249 
7250 	return 0;
7251 }
7252 
7253 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7254 					     struct list_head **iter)
7255 {
7256 	struct netdev_adjacent *lower;
7257 
7258 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7259 	if (&lower->list == &dev->adj_list.lower)
7260 		return NULL;
7261 
7262 	*iter = &lower->list;
7263 
7264 	return lower->dev;
7265 }
7266 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7267 
7268 static u8 __netdev_upper_depth(struct net_device *dev)
7269 {
7270 	struct net_device *udev;
7271 	struct list_head *iter;
7272 	u8 max_depth = 0;
7273 	bool ignore;
7274 
7275 	for (iter = &dev->adj_list.upper,
7276 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7277 	     udev;
7278 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7279 		if (ignore)
7280 			continue;
7281 		if (max_depth < udev->upper_level)
7282 			max_depth = udev->upper_level;
7283 	}
7284 
7285 	return max_depth;
7286 }
7287 
7288 static u8 __netdev_lower_depth(struct net_device *dev)
7289 {
7290 	struct net_device *ldev;
7291 	struct list_head *iter;
7292 	u8 max_depth = 0;
7293 	bool ignore;
7294 
7295 	for (iter = &dev->adj_list.lower,
7296 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7297 	     ldev;
7298 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7299 		if (ignore)
7300 			continue;
7301 		if (max_depth < ldev->lower_level)
7302 			max_depth = ldev->lower_level;
7303 	}
7304 
7305 	return max_depth;
7306 }
7307 
7308 static int __netdev_update_upper_level(struct net_device *dev,
7309 				       struct netdev_nested_priv *__unused)
7310 {
7311 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7312 	return 0;
7313 }
7314 
7315 #ifdef CONFIG_LOCKDEP
7316 static LIST_HEAD(net_unlink_list);
7317 
7318 static void net_unlink_todo(struct net_device *dev)
7319 {
7320 	if (list_empty(&dev->unlink_list))
7321 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7322 }
7323 #endif
7324 
7325 static int __netdev_update_lower_level(struct net_device *dev,
7326 				       struct netdev_nested_priv *priv)
7327 {
7328 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7329 
7330 #ifdef CONFIG_LOCKDEP
7331 	if (!priv)
7332 		return 0;
7333 
7334 	if (priv->flags & NESTED_SYNC_IMM)
7335 		dev->nested_level = dev->lower_level - 1;
7336 	if (priv->flags & NESTED_SYNC_TODO)
7337 		net_unlink_todo(dev);
7338 #endif
7339 	return 0;
7340 }
7341 
7342 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7343 				  int (*fn)(struct net_device *dev,
7344 					    struct netdev_nested_priv *priv),
7345 				  struct netdev_nested_priv *priv)
7346 {
7347 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7348 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7349 	int ret, cur = 0;
7350 
7351 	now = dev;
7352 	iter = &dev->adj_list.lower;
7353 
7354 	while (1) {
7355 		if (now != dev) {
7356 			ret = fn(now, priv);
7357 			if (ret)
7358 				return ret;
7359 		}
7360 
7361 		next = NULL;
7362 		while (1) {
7363 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7364 			if (!ldev)
7365 				break;
7366 
7367 			next = ldev;
7368 			niter = &ldev->adj_list.lower;
7369 			dev_stack[cur] = now;
7370 			iter_stack[cur++] = iter;
7371 			break;
7372 		}
7373 
7374 		if (!next) {
7375 			if (!cur)
7376 				return 0;
7377 			next = dev_stack[--cur];
7378 			niter = iter_stack[cur];
7379 		}
7380 
7381 		now = next;
7382 		iter = niter;
7383 	}
7384 
7385 	return 0;
7386 }
7387 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7388 
7389 /**
7390  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7391  *				       lower neighbour list, RCU
7392  *				       variant
7393  * @dev: device
7394  *
7395  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7396  * list. The caller must hold RCU read lock.
7397  */
7398 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7399 {
7400 	struct netdev_adjacent *lower;
7401 
7402 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7403 			struct netdev_adjacent, list);
7404 	if (lower)
7405 		return lower->private;
7406 	return NULL;
7407 }
7408 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7409 
7410 /**
7411  * netdev_master_upper_dev_get_rcu - Get master upper device
7412  * @dev: device
7413  *
7414  * Find a master upper device and return pointer to it or NULL in case
7415  * it's not there. The caller must hold the RCU read lock.
7416  */
7417 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7418 {
7419 	struct netdev_adjacent *upper;
7420 
7421 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7422 				       struct netdev_adjacent, list);
7423 	if (upper && likely(upper->master))
7424 		return upper->dev;
7425 	return NULL;
7426 }
7427 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7428 
7429 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7430 			      struct net_device *adj_dev,
7431 			      struct list_head *dev_list)
7432 {
7433 	char linkname[IFNAMSIZ+7];
7434 
7435 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7436 		"upper_%s" : "lower_%s", adj_dev->name);
7437 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7438 				 linkname);
7439 }
7440 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7441 			       char *name,
7442 			       struct list_head *dev_list)
7443 {
7444 	char linkname[IFNAMSIZ+7];
7445 
7446 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7447 		"upper_%s" : "lower_%s", name);
7448 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7449 }
7450 
7451 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7452 						 struct net_device *adj_dev,
7453 						 struct list_head *dev_list)
7454 {
7455 	return (dev_list == &dev->adj_list.upper ||
7456 		dev_list == &dev->adj_list.lower) &&
7457 		net_eq(dev_net(dev), dev_net(adj_dev));
7458 }
7459 
7460 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7461 					struct net_device *adj_dev,
7462 					struct list_head *dev_list,
7463 					void *private, bool master)
7464 {
7465 	struct netdev_adjacent *adj;
7466 	int ret;
7467 
7468 	adj = __netdev_find_adj(adj_dev, dev_list);
7469 
7470 	if (adj) {
7471 		adj->ref_nr += 1;
7472 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7473 			 dev->name, adj_dev->name, adj->ref_nr);
7474 
7475 		return 0;
7476 	}
7477 
7478 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7479 	if (!adj)
7480 		return -ENOMEM;
7481 
7482 	adj->dev = adj_dev;
7483 	adj->master = master;
7484 	adj->ref_nr = 1;
7485 	adj->private = private;
7486 	adj->ignore = false;
7487 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7488 
7489 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7490 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7491 
7492 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7493 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7494 		if (ret)
7495 			goto free_adj;
7496 	}
7497 
7498 	/* Ensure that master link is always the first item in list. */
7499 	if (master) {
7500 		ret = sysfs_create_link(&(dev->dev.kobj),
7501 					&(adj_dev->dev.kobj), "master");
7502 		if (ret)
7503 			goto remove_symlinks;
7504 
7505 		list_add_rcu(&adj->list, dev_list);
7506 	} else {
7507 		list_add_tail_rcu(&adj->list, dev_list);
7508 	}
7509 
7510 	return 0;
7511 
7512 remove_symlinks:
7513 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7514 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7515 free_adj:
7516 	netdev_put(adj_dev, &adj->dev_tracker);
7517 	kfree(adj);
7518 
7519 	return ret;
7520 }
7521 
7522 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7523 					 struct net_device *adj_dev,
7524 					 u16 ref_nr,
7525 					 struct list_head *dev_list)
7526 {
7527 	struct netdev_adjacent *adj;
7528 
7529 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7530 		 dev->name, adj_dev->name, ref_nr);
7531 
7532 	adj = __netdev_find_adj(adj_dev, dev_list);
7533 
7534 	if (!adj) {
7535 		pr_err("Adjacency does not exist for device %s from %s\n",
7536 		       dev->name, adj_dev->name);
7537 		WARN_ON(1);
7538 		return;
7539 	}
7540 
7541 	if (adj->ref_nr > ref_nr) {
7542 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7543 			 dev->name, adj_dev->name, ref_nr,
7544 			 adj->ref_nr - ref_nr);
7545 		adj->ref_nr -= ref_nr;
7546 		return;
7547 	}
7548 
7549 	if (adj->master)
7550 		sysfs_remove_link(&(dev->dev.kobj), "master");
7551 
7552 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7553 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7554 
7555 	list_del_rcu(&adj->list);
7556 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7557 		 adj_dev->name, dev->name, adj_dev->name);
7558 	netdev_put(adj_dev, &adj->dev_tracker);
7559 	kfree_rcu(adj, rcu);
7560 }
7561 
7562 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7563 					    struct net_device *upper_dev,
7564 					    struct list_head *up_list,
7565 					    struct list_head *down_list,
7566 					    void *private, bool master)
7567 {
7568 	int ret;
7569 
7570 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7571 					   private, master);
7572 	if (ret)
7573 		return ret;
7574 
7575 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7576 					   private, false);
7577 	if (ret) {
7578 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7579 		return ret;
7580 	}
7581 
7582 	return 0;
7583 }
7584 
7585 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7586 					       struct net_device *upper_dev,
7587 					       u16 ref_nr,
7588 					       struct list_head *up_list,
7589 					       struct list_head *down_list)
7590 {
7591 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7592 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7593 }
7594 
7595 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7596 						struct net_device *upper_dev,
7597 						void *private, bool master)
7598 {
7599 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7600 						&dev->adj_list.upper,
7601 						&upper_dev->adj_list.lower,
7602 						private, master);
7603 }
7604 
7605 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7606 						   struct net_device *upper_dev)
7607 {
7608 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7609 					   &dev->adj_list.upper,
7610 					   &upper_dev->adj_list.lower);
7611 }
7612 
7613 static int __netdev_upper_dev_link(struct net_device *dev,
7614 				   struct net_device *upper_dev, bool master,
7615 				   void *upper_priv, void *upper_info,
7616 				   struct netdev_nested_priv *priv,
7617 				   struct netlink_ext_ack *extack)
7618 {
7619 	struct netdev_notifier_changeupper_info changeupper_info = {
7620 		.info = {
7621 			.dev = dev,
7622 			.extack = extack,
7623 		},
7624 		.upper_dev = upper_dev,
7625 		.master = master,
7626 		.linking = true,
7627 		.upper_info = upper_info,
7628 	};
7629 	struct net_device *master_dev;
7630 	int ret = 0;
7631 
7632 	ASSERT_RTNL();
7633 
7634 	if (dev == upper_dev)
7635 		return -EBUSY;
7636 
7637 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7638 	if (__netdev_has_upper_dev(upper_dev, dev))
7639 		return -EBUSY;
7640 
7641 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7642 		return -EMLINK;
7643 
7644 	if (!master) {
7645 		if (__netdev_has_upper_dev(dev, upper_dev))
7646 			return -EEXIST;
7647 	} else {
7648 		master_dev = __netdev_master_upper_dev_get(dev);
7649 		if (master_dev)
7650 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7651 	}
7652 
7653 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7654 					    &changeupper_info.info);
7655 	ret = notifier_to_errno(ret);
7656 	if (ret)
7657 		return ret;
7658 
7659 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7660 						   master);
7661 	if (ret)
7662 		return ret;
7663 
7664 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7665 					    &changeupper_info.info);
7666 	ret = notifier_to_errno(ret);
7667 	if (ret)
7668 		goto rollback;
7669 
7670 	__netdev_update_upper_level(dev, NULL);
7671 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7672 
7673 	__netdev_update_lower_level(upper_dev, priv);
7674 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7675 				    priv);
7676 
7677 	return 0;
7678 
7679 rollback:
7680 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7681 
7682 	return ret;
7683 }
7684 
7685 /**
7686  * netdev_upper_dev_link - Add a link to the upper device
7687  * @dev: device
7688  * @upper_dev: new upper device
7689  * @extack: netlink extended ack
7690  *
7691  * Adds a link to device which is upper to this one. The caller must hold
7692  * the RTNL lock. On a failure a negative errno code is returned.
7693  * On success the reference counts are adjusted and the function
7694  * returns zero.
7695  */
7696 int netdev_upper_dev_link(struct net_device *dev,
7697 			  struct net_device *upper_dev,
7698 			  struct netlink_ext_ack *extack)
7699 {
7700 	struct netdev_nested_priv priv = {
7701 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7702 		.data = NULL,
7703 	};
7704 
7705 	return __netdev_upper_dev_link(dev, upper_dev, false,
7706 				       NULL, NULL, &priv, extack);
7707 }
7708 EXPORT_SYMBOL(netdev_upper_dev_link);
7709 
7710 /**
7711  * netdev_master_upper_dev_link - Add a master link to the upper device
7712  * @dev: device
7713  * @upper_dev: new upper device
7714  * @upper_priv: upper device private
7715  * @upper_info: upper info to be passed down via notifier
7716  * @extack: netlink extended ack
7717  *
7718  * Adds a link to device which is upper to this one. In this case, only
7719  * one master upper device can be linked, although other non-master devices
7720  * might be linked as well. The caller must hold the RTNL lock.
7721  * On a failure a negative errno code is returned. On success the reference
7722  * counts are adjusted and the function returns zero.
7723  */
7724 int netdev_master_upper_dev_link(struct net_device *dev,
7725 				 struct net_device *upper_dev,
7726 				 void *upper_priv, void *upper_info,
7727 				 struct netlink_ext_ack *extack)
7728 {
7729 	struct netdev_nested_priv priv = {
7730 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7731 		.data = NULL,
7732 	};
7733 
7734 	return __netdev_upper_dev_link(dev, upper_dev, true,
7735 				       upper_priv, upper_info, &priv, extack);
7736 }
7737 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7738 
7739 static void __netdev_upper_dev_unlink(struct net_device *dev,
7740 				      struct net_device *upper_dev,
7741 				      struct netdev_nested_priv *priv)
7742 {
7743 	struct netdev_notifier_changeupper_info changeupper_info = {
7744 		.info = {
7745 			.dev = dev,
7746 		},
7747 		.upper_dev = upper_dev,
7748 		.linking = false,
7749 	};
7750 
7751 	ASSERT_RTNL();
7752 
7753 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7754 
7755 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7756 				      &changeupper_info.info);
7757 
7758 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7759 
7760 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7761 				      &changeupper_info.info);
7762 
7763 	__netdev_update_upper_level(dev, NULL);
7764 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7765 
7766 	__netdev_update_lower_level(upper_dev, priv);
7767 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7768 				    priv);
7769 }
7770 
7771 /**
7772  * netdev_upper_dev_unlink - Removes a link to upper device
7773  * @dev: device
7774  * @upper_dev: new upper device
7775  *
7776  * Removes a link to device which is upper to this one. The caller must hold
7777  * the RTNL lock.
7778  */
7779 void netdev_upper_dev_unlink(struct net_device *dev,
7780 			     struct net_device *upper_dev)
7781 {
7782 	struct netdev_nested_priv priv = {
7783 		.flags = NESTED_SYNC_TODO,
7784 		.data = NULL,
7785 	};
7786 
7787 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
7788 }
7789 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7790 
7791 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7792 				      struct net_device *lower_dev,
7793 				      bool val)
7794 {
7795 	struct netdev_adjacent *adj;
7796 
7797 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7798 	if (adj)
7799 		adj->ignore = val;
7800 
7801 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7802 	if (adj)
7803 		adj->ignore = val;
7804 }
7805 
7806 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7807 					struct net_device *lower_dev)
7808 {
7809 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7810 }
7811 
7812 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7813 				       struct net_device *lower_dev)
7814 {
7815 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7816 }
7817 
7818 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7819 				   struct net_device *new_dev,
7820 				   struct net_device *dev,
7821 				   struct netlink_ext_ack *extack)
7822 {
7823 	struct netdev_nested_priv priv = {
7824 		.flags = 0,
7825 		.data = NULL,
7826 	};
7827 	int err;
7828 
7829 	if (!new_dev)
7830 		return 0;
7831 
7832 	if (old_dev && new_dev != old_dev)
7833 		netdev_adjacent_dev_disable(dev, old_dev);
7834 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7835 				      extack);
7836 	if (err) {
7837 		if (old_dev && new_dev != old_dev)
7838 			netdev_adjacent_dev_enable(dev, old_dev);
7839 		return err;
7840 	}
7841 
7842 	return 0;
7843 }
7844 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7845 
7846 void netdev_adjacent_change_commit(struct net_device *old_dev,
7847 				   struct net_device *new_dev,
7848 				   struct net_device *dev)
7849 {
7850 	struct netdev_nested_priv priv = {
7851 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7852 		.data = NULL,
7853 	};
7854 
7855 	if (!new_dev || !old_dev)
7856 		return;
7857 
7858 	if (new_dev == old_dev)
7859 		return;
7860 
7861 	netdev_adjacent_dev_enable(dev, old_dev);
7862 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
7863 }
7864 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7865 
7866 void netdev_adjacent_change_abort(struct net_device *old_dev,
7867 				  struct net_device *new_dev,
7868 				  struct net_device *dev)
7869 {
7870 	struct netdev_nested_priv priv = {
7871 		.flags = 0,
7872 		.data = NULL,
7873 	};
7874 
7875 	if (!new_dev)
7876 		return;
7877 
7878 	if (old_dev && new_dev != old_dev)
7879 		netdev_adjacent_dev_enable(dev, old_dev);
7880 
7881 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
7882 }
7883 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7884 
7885 /**
7886  * netdev_bonding_info_change - Dispatch event about slave change
7887  * @dev: device
7888  * @bonding_info: info to dispatch
7889  *
7890  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7891  * The caller must hold the RTNL lock.
7892  */
7893 void netdev_bonding_info_change(struct net_device *dev,
7894 				struct netdev_bonding_info *bonding_info)
7895 {
7896 	struct netdev_notifier_bonding_info info = {
7897 		.info.dev = dev,
7898 	};
7899 
7900 	memcpy(&info.bonding_info, bonding_info,
7901 	       sizeof(struct netdev_bonding_info));
7902 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7903 				      &info.info);
7904 }
7905 EXPORT_SYMBOL(netdev_bonding_info_change);
7906 
7907 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7908 					   struct netlink_ext_ack *extack)
7909 {
7910 	struct netdev_notifier_offload_xstats_info info = {
7911 		.info.dev = dev,
7912 		.info.extack = extack,
7913 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7914 	};
7915 	int err;
7916 	int rc;
7917 
7918 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7919 					 GFP_KERNEL);
7920 	if (!dev->offload_xstats_l3)
7921 		return -ENOMEM;
7922 
7923 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7924 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
7925 						  &info.info);
7926 	err = notifier_to_errno(rc);
7927 	if (err)
7928 		goto free_stats;
7929 
7930 	return 0;
7931 
7932 free_stats:
7933 	kfree(dev->offload_xstats_l3);
7934 	dev->offload_xstats_l3 = NULL;
7935 	return err;
7936 }
7937 
7938 int netdev_offload_xstats_enable(struct net_device *dev,
7939 				 enum netdev_offload_xstats_type type,
7940 				 struct netlink_ext_ack *extack)
7941 {
7942 	ASSERT_RTNL();
7943 
7944 	if (netdev_offload_xstats_enabled(dev, type))
7945 		return -EALREADY;
7946 
7947 	switch (type) {
7948 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7949 		return netdev_offload_xstats_enable_l3(dev, extack);
7950 	}
7951 
7952 	WARN_ON(1);
7953 	return -EINVAL;
7954 }
7955 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7956 
7957 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7958 {
7959 	struct netdev_notifier_offload_xstats_info info = {
7960 		.info.dev = dev,
7961 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7962 	};
7963 
7964 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
7965 				      &info.info);
7966 	kfree(dev->offload_xstats_l3);
7967 	dev->offload_xstats_l3 = NULL;
7968 }
7969 
7970 int netdev_offload_xstats_disable(struct net_device *dev,
7971 				  enum netdev_offload_xstats_type type)
7972 {
7973 	ASSERT_RTNL();
7974 
7975 	if (!netdev_offload_xstats_enabled(dev, type))
7976 		return -EALREADY;
7977 
7978 	switch (type) {
7979 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7980 		netdev_offload_xstats_disable_l3(dev);
7981 		return 0;
7982 	}
7983 
7984 	WARN_ON(1);
7985 	return -EINVAL;
7986 }
7987 EXPORT_SYMBOL(netdev_offload_xstats_disable);
7988 
7989 static void netdev_offload_xstats_disable_all(struct net_device *dev)
7990 {
7991 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
7992 }
7993 
7994 static struct rtnl_hw_stats64 *
7995 netdev_offload_xstats_get_ptr(const struct net_device *dev,
7996 			      enum netdev_offload_xstats_type type)
7997 {
7998 	switch (type) {
7999 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8000 		return dev->offload_xstats_l3;
8001 	}
8002 
8003 	WARN_ON(1);
8004 	return NULL;
8005 }
8006 
8007 bool netdev_offload_xstats_enabled(const struct net_device *dev,
8008 				   enum netdev_offload_xstats_type type)
8009 {
8010 	ASSERT_RTNL();
8011 
8012 	return netdev_offload_xstats_get_ptr(dev, type);
8013 }
8014 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8015 
8016 struct netdev_notifier_offload_xstats_ru {
8017 	bool used;
8018 };
8019 
8020 struct netdev_notifier_offload_xstats_rd {
8021 	struct rtnl_hw_stats64 stats;
8022 	bool used;
8023 };
8024 
8025 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8026 				  const struct rtnl_hw_stats64 *src)
8027 {
8028 	dest->rx_packets	  += src->rx_packets;
8029 	dest->tx_packets	  += src->tx_packets;
8030 	dest->rx_bytes		  += src->rx_bytes;
8031 	dest->tx_bytes		  += src->tx_bytes;
8032 	dest->rx_errors		  += src->rx_errors;
8033 	dest->tx_errors		  += src->tx_errors;
8034 	dest->rx_dropped	  += src->rx_dropped;
8035 	dest->tx_dropped	  += src->tx_dropped;
8036 	dest->multicast		  += src->multicast;
8037 }
8038 
8039 static int netdev_offload_xstats_get_used(struct net_device *dev,
8040 					  enum netdev_offload_xstats_type type,
8041 					  bool *p_used,
8042 					  struct netlink_ext_ack *extack)
8043 {
8044 	struct netdev_notifier_offload_xstats_ru report_used = {};
8045 	struct netdev_notifier_offload_xstats_info info = {
8046 		.info.dev = dev,
8047 		.info.extack = extack,
8048 		.type = type,
8049 		.report_used = &report_used,
8050 	};
8051 	int rc;
8052 
8053 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8054 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8055 					   &info.info);
8056 	*p_used = report_used.used;
8057 	return notifier_to_errno(rc);
8058 }
8059 
8060 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8061 					   enum netdev_offload_xstats_type type,
8062 					   struct rtnl_hw_stats64 *p_stats,
8063 					   bool *p_used,
8064 					   struct netlink_ext_ack *extack)
8065 {
8066 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8067 	struct netdev_notifier_offload_xstats_info info = {
8068 		.info.dev = dev,
8069 		.info.extack = extack,
8070 		.type = type,
8071 		.report_delta = &report_delta,
8072 	};
8073 	struct rtnl_hw_stats64 *stats;
8074 	int rc;
8075 
8076 	stats = netdev_offload_xstats_get_ptr(dev, type);
8077 	if (WARN_ON(!stats))
8078 		return -EINVAL;
8079 
8080 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8081 					   &info.info);
8082 
8083 	/* Cache whatever we got, even if there was an error, otherwise the
8084 	 * successful stats retrievals would get lost.
8085 	 */
8086 	netdev_hw_stats64_add(stats, &report_delta.stats);
8087 
8088 	if (p_stats)
8089 		*p_stats = *stats;
8090 	*p_used = report_delta.used;
8091 
8092 	return notifier_to_errno(rc);
8093 }
8094 
8095 int netdev_offload_xstats_get(struct net_device *dev,
8096 			      enum netdev_offload_xstats_type type,
8097 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8098 			      struct netlink_ext_ack *extack)
8099 {
8100 	ASSERT_RTNL();
8101 
8102 	if (p_stats)
8103 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8104 						       p_used, extack);
8105 	else
8106 		return netdev_offload_xstats_get_used(dev, type, p_used,
8107 						      extack);
8108 }
8109 EXPORT_SYMBOL(netdev_offload_xstats_get);
8110 
8111 void
8112 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8113 				   const struct rtnl_hw_stats64 *stats)
8114 {
8115 	report_delta->used = true;
8116 	netdev_hw_stats64_add(&report_delta->stats, stats);
8117 }
8118 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8119 
8120 void
8121 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8122 {
8123 	report_used->used = true;
8124 }
8125 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8126 
8127 void netdev_offload_xstats_push_delta(struct net_device *dev,
8128 				      enum netdev_offload_xstats_type type,
8129 				      const struct rtnl_hw_stats64 *p_stats)
8130 {
8131 	struct rtnl_hw_stats64 *stats;
8132 
8133 	ASSERT_RTNL();
8134 
8135 	stats = netdev_offload_xstats_get_ptr(dev, type);
8136 	if (WARN_ON(!stats))
8137 		return;
8138 
8139 	netdev_hw_stats64_add(stats, p_stats);
8140 }
8141 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8142 
8143 /**
8144  * netdev_get_xmit_slave - Get the xmit slave of master device
8145  * @dev: device
8146  * @skb: The packet
8147  * @all_slaves: assume all the slaves are active
8148  *
8149  * The reference counters are not incremented so the caller must be
8150  * careful with locks. The caller must hold RCU lock.
8151  * %NULL is returned if no slave is found.
8152  */
8153 
8154 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8155 					 struct sk_buff *skb,
8156 					 bool all_slaves)
8157 {
8158 	const struct net_device_ops *ops = dev->netdev_ops;
8159 
8160 	if (!ops->ndo_get_xmit_slave)
8161 		return NULL;
8162 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8163 }
8164 EXPORT_SYMBOL(netdev_get_xmit_slave);
8165 
8166 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8167 						  struct sock *sk)
8168 {
8169 	const struct net_device_ops *ops = dev->netdev_ops;
8170 
8171 	if (!ops->ndo_sk_get_lower_dev)
8172 		return NULL;
8173 	return ops->ndo_sk_get_lower_dev(dev, sk);
8174 }
8175 
8176 /**
8177  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8178  * @dev: device
8179  * @sk: the socket
8180  *
8181  * %NULL is returned if no lower device is found.
8182  */
8183 
8184 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8185 					    struct sock *sk)
8186 {
8187 	struct net_device *lower;
8188 
8189 	lower = netdev_sk_get_lower_dev(dev, sk);
8190 	while (lower) {
8191 		dev = lower;
8192 		lower = netdev_sk_get_lower_dev(dev, sk);
8193 	}
8194 
8195 	return dev;
8196 }
8197 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8198 
8199 static void netdev_adjacent_add_links(struct net_device *dev)
8200 {
8201 	struct netdev_adjacent *iter;
8202 
8203 	struct net *net = dev_net(dev);
8204 
8205 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8206 		if (!net_eq(net, dev_net(iter->dev)))
8207 			continue;
8208 		netdev_adjacent_sysfs_add(iter->dev, dev,
8209 					  &iter->dev->adj_list.lower);
8210 		netdev_adjacent_sysfs_add(dev, iter->dev,
8211 					  &dev->adj_list.upper);
8212 	}
8213 
8214 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8215 		if (!net_eq(net, dev_net(iter->dev)))
8216 			continue;
8217 		netdev_adjacent_sysfs_add(iter->dev, dev,
8218 					  &iter->dev->adj_list.upper);
8219 		netdev_adjacent_sysfs_add(dev, iter->dev,
8220 					  &dev->adj_list.lower);
8221 	}
8222 }
8223 
8224 static void netdev_adjacent_del_links(struct net_device *dev)
8225 {
8226 	struct netdev_adjacent *iter;
8227 
8228 	struct net *net = dev_net(dev);
8229 
8230 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8231 		if (!net_eq(net, dev_net(iter->dev)))
8232 			continue;
8233 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8234 					  &iter->dev->adj_list.lower);
8235 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8236 					  &dev->adj_list.upper);
8237 	}
8238 
8239 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8240 		if (!net_eq(net, dev_net(iter->dev)))
8241 			continue;
8242 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8243 					  &iter->dev->adj_list.upper);
8244 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8245 					  &dev->adj_list.lower);
8246 	}
8247 }
8248 
8249 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8250 {
8251 	struct netdev_adjacent *iter;
8252 
8253 	struct net *net = dev_net(dev);
8254 
8255 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8256 		if (!net_eq(net, dev_net(iter->dev)))
8257 			continue;
8258 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8259 					  &iter->dev->adj_list.lower);
8260 		netdev_adjacent_sysfs_add(iter->dev, dev,
8261 					  &iter->dev->adj_list.lower);
8262 	}
8263 
8264 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8265 		if (!net_eq(net, dev_net(iter->dev)))
8266 			continue;
8267 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8268 					  &iter->dev->adj_list.upper);
8269 		netdev_adjacent_sysfs_add(iter->dev, dev,
8270 					  &iter->dev->adj_list.upper);
8271 	}
8272 }
8273 
8274 void *netdev_lower_dev_get_private(struct net_device *dev,
8275 				   struct net_device *lower_dev)
8276 {
8277 	struct netdev_adjacent *lower;
8278 
8279 	if (!lower_dev)
8280 		return NULL;
8281 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8282 	if (!lower)
8283 		return NULL;
8284 
8285 	return lower->private;
8286 }
8287 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8288 
8289 
8290 /**
8291  * netdev_lower_state_changed - Dispatch event about lower device state change
8292  * @lower_dev: device
8293  * @lower_state_info: state to dispatch
8294  *
8295  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8296  * The caller must hold the RTNL lock.
8297  */
8298 void netdev_lower_state_changed(struct net_device *lower_dev,
8299 				void *lower_state_info)
8300 {
8301 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8302 		.info.dev = lower_dev,
8303 	};
8304 
8305 	ASSERT_RTNL();
8306 	changelowerstate_info.lower_state_info = lower_state_info;
8307 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8308 				      &changelowerstate_info.info);
8309 }
8310 EXPORT_SYMBOL(netdev_lower_state_changed);
8311 
8312 static void dev_change_rx_flags(struct net_device *dev, int flags)
8313 {
8314 	const struct net_device_ops *ops = dev->netdev_ops;
8315 
8316 	if (ops->ndo_change_rx_flags)
8317 		ops->ndo_change_rx_flags(dev, flags);
8318 }
8319 
8320 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8321 {
8322 	unsigned int old_flags = dev->flags;
8323 	kuid_t uid;
8324 	kgid_t gid;
8325 
8326 	ASSERT_RTNL();
8327 
8328 	dev->flags |= IFF_PROMISC;
8329 	dev->promiscuity += inc;
8330 	if (dev->promiscuity == 0) {
8331 		/*
8332 		 * Avoid overflow.
8333 		 * If inc causes overflow, untouch promisc and return error.
8334 		 */
8335 		if (inc < 0)
8336 			dev->flags &= ~IFF_PROMISC;
8337 		else {
8338 			dev->promiscuity -= inc;
8339 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8340 			return -EOVERFLOW;
8341 		}
8342 	}
8343 	if (dev->flags != old_flags) {
8344 		netdev_info(dev, "%s promiscuous mode\n",
8345 			    dev->flags & IFF_PROMISC ? "entered" : "left");
8346 		if (audit_enabled) {
8347 			current_uid_gid(&uid, &gid);
8348 			audit_log(audit_context(), GFP_ATOMIC,
8349 				  AUDIT_ANOM_PROMISCUOUS,
8350 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8351 				  dev->name, (dev->flags & IFF_PROMISC),
8352 				  (old_flags & IFF_PROMISC),
8353 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8354 				  from_kuid(&init_user_ns, uid),
8355 				  from_kgid(&init_user_ns, gid),
8356 				  audit_get_sessionid(current));
8357 		}
8358 
8359 		dev_change_rx_flags(dev, IFF_PROMISC);
8360 	}
8361 	if (notify)
8362 		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8363 	return 0;
8364 }
8365 
8366 /**
8367  *	dev_set_promiscuity	- update promiscuity count on a device
8368  *	@dev: device
8369  *	@inc: modifier
8370  *
8371  *	Add or remove promiscuity from a device. While the count in the device
8372  *	remains above zero the interface remains promiscuous. Once it hits zero
8373  *	the device reverts back to normal filtering operation. A negative inc
8374  *	value is used to drop promiscuity on the device.
8375  *	Return 0 if successful or a negative errno code on error.
8376  */
8377 int dev_set_promiscuity(struct net_device *dev, int inc)
8378 {
8379 	unsigned int old_flags = dev->flags;
8380 	int err;
8381 
8382 	err = __dev_set_promiscuity(dev, inc, true);
8383 	if (err < 0)
8384 		return err;
8385 	if (dev->flags != old_flags)
8386 		dev_set_rx_mode(dev);
8387 	return err;
8388 }
8389 EXPORT_SYMBOL(dev_set_promiscuity);
8390 
8391 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8392 {
8393 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8394 
8395 	ASSERT_RTNL();
8396 
8397 	dev->flags |= IFF_ALLMULTI;
8398 	dev->allmulti += inc;
8399 	if (dev->allmulti == 0) {
8400 		/*
8401 		 * Avoid overflow.
8402 		 * If inc causes overflow, untouch allmulti and return error.
8403 		 */
8404 		if (inc < 0)
8405 			dev->flags &= ~IFF_ALLMULTI;
8406 		else {
8407 			dev->allmulti -= inc;
8408 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8409 			return -EOVERFLOW;
8410 		}
8411 	}
8412 	if (dev->flags ^ old_flags) {
8413 		netdev_info(dev, "%s allmulticast mode\n",
8414 			    dev->flags & IFF_ALLMULTI ? "entered" : "left");
8415 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8416 		dev_set_rx_mode(dev);
8417 		if (notify)
8418 			__dev_notify_flags(dev, old_flags,
8419 					   dev->gflags ^ old_gflags, 0, NULL);
8420 	}
8421 	return 0;
8422 }
8423 
8424 /**
8425  *	dev_set_allmulti	- update allmulti count on a device
8426  *	@dev: device
8427  *	@inc: modifier
8428  *
8429  *	Add or remove reception of all multicast frames to a device. While the
8430  *	count in the device remains above zero the interface remains listening
8431  *	to all interfaces. Once it hits zero the device reverts back to normal
8432  *	filtering operation. A negative @inc value is used to drop the counter
8433  *	when releasing a resource needing all multicasts.
8434  *	Return 0 if successful or a negative errno code on error.
8435  */
8436 
8437 int dev_set_allmulti(struct net_device *dev, int inc)
8438 {
8439 	return __dev_set_allmulti(dev, inc, true);
8440 }
8441 EXPORT_SYMBOL(dev_set_allmulti);
8442 
8443 /*
8444  *	Upload unicast and multicast address lists to device and
8445  *	configure RX filtering. When the device doesn't support unicast
8446  *	filtering it is put in promiscuous mode while unicast addresses
8447  *	are present.
8448  */
8449 void __dev_set_rx_mode(struct net_device *dev)
8450 {
8451 	const struct net_device_ops *ops = dev->netdev_ops;
8452 
8453 	/* dev_open will call this function so the list will stay sane. */
8454 	if (!(dev->flags&IFF_UP))
8455 		return;
8456 
8457 	if (!netif_device_present(dev))
8458 		return;
8459 
8460 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8461 		/* Unicast addresses changes may only happen under the rtnl,
8462 		 * therefore calling __dev_set_promiscuity here is safe.
8463 		 */
8464 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8465 			__dev_set_promiscuity(dev, 1, false);
8466 			dev->uc_promisc = true;
8467 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8468 			__dev_set_promiscuity(dev, -1, false);
8469 			dev->uc_promisc = false;
8470 		}
8471 	}
8472 
8473 	if (ops->ndo_set_rx_mode)
8474 		ops->ndo_set_rx_mode(dev);
8475 }
8476 
8477 void dev_set_rx_mode(struct net_device *dev)
8478 {
8479 	netif_addr_lock_bh(dev);
8480 	__dev_set_rx_mode(dev);
8481 	netif_addr_unlock_bh(dev);
8482 }
8483 
8484 /**
8485  *	dev_get_flags - get flags reported to userspace
8486  *	@dev: device
8487  *
8488  *	Get the combination of flag bits exported through APIs to userspace.
8489  */
8490 unsigned int dev_get_flags(const struct net_device *dev)
8491 {
8492 	unsigned int flags;
8493 
8494 	flags = (dev->flags & ~(IFF_PROMISC |
8495 				IFF_ALLMULTI |
8496 				IFF_RUNNING |
8497 				IFF_LOWER_UP |
8498 				IFF_DORMANT)) |
8499 		(dev->gflags & (IFF_PROMISC |
8500 				IFF_ALLMULTI));
8501 
8502 	if (netif_running(dev)) {
8503 		if (netif_oper_up(dev))
8504 			flags |= IFF_RUNNING;
8505 		if (netif_carrier_ok(dev))
8506 			flags |= IFF_LOWER_UP;
8507 		if (netif_dormant(dev))
8508 			flags |= IFF_DORMANT;
8509 	}
8510 
8511 	return flags;
8512 }
8513 EXPORT_SYMBOL(dev_get_flags);
8514 
8515 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8516 		       struct netlink_ext_ack *extack)
8517 {
8518 	unsigned int old_flags = dev->flags;
8519 	int ret;
8520 
8521 	ASSERT_RTNL();
8522 
8523 	/*
8524 	 *	Set the flags on our device.
8525 	 */
8526 
8527 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8528 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8529 			       IFF_AUTOMEDIA)) |
8530 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8531 				    IFF_ALLMULTI));
8532 
8533 	/*
8534 	 *	Load in the correct multicast list now the flags have changed.
8535 	 */
8536 
8537 	if ((old_flags ^ flags) & IFF_MULTICAST)
8538 		dev_change_rx_flags(dev, IFF_MULTICAST);
8539 
8540 	dev_set_rx_mode(dev);
8541 
8542 	/*
8543 	 *	Have we downed the interface. We handle IFF_UP ourselves
8544 	 *	according to user attempts to set it, rather than blindly
8545 	 *	setting it.
8546 	 */
8547 
8548 	ret = 0;
8549 	if ((old_flags ^ flags) & IFF_UP) {
8550 		if (old_flags & IFF_UP)
8551 			__dev_close(dev);
8552 		else
8553 			ret = __dev_open(dev, extack);
8554 	}
8555 
8556 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8557 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8558 		unsigned int old_flags = dev->flags;
8559 
8560 		dev->gflags ^= IFF_PROMISC;
8561 
8562 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8563 			if (dev->flags != old_flags)
8564 				dev_set_rx_mode(dev);
8565 	}
8566 
8567 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8568 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8569 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8570 	 */
8571 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8572 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8573 
8574 		dev->gflags ^= IFF_ALLMULTI;
8575 		__dev_set_allmulti(dev, inc, false);
8576 	}
8577 
8578 	return ret;
8579 }
8580 
8581 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8582 			unsigned int gchanges, u32 portid,
8583 			const struct nlmsghdr *nlh)
8584 {
8585 	unsigned int changes = dev->flags ^ old_flags;
8586 
8587 	if (gchanges)
8588 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8589 
8590 	if (changes & IFF_UP) {
8591 		if (dev->flags & IFF_UP)
8592 			call_netdevice_notifiers(NETDEV_UP, dev);
8593 		else
8594 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8595 	}
8596 
8597 	if (dev->flags & IFF_UP &&
8598 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8599 		struct netdev_notifier_change_info change_info = {
8600 			.info = {
8601 				.dev = dev,
8602 			},
8603 			.flags_changed = changes,
8604 		};
8605 
8606 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8607 	}
8608 }
8609 
8610 /**
8611  *	dev_change_flags - change device settings
8612  *	@dev: device
8613  *	@flags: device state flags
8614  *	@extack: netlink extended ack
8615  *
8616  *	Change settings on device based state flags. The flags are
8617  *	in the userspace exported format.
8618  */
8619 int dev_change_flags(struct net_device *dev, unsigned int flags,
8620 		     struct netlink_ext_ack *extack)
8621 {
8622 	int ret;
8623 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8624 
8625 	ret = __dev_change_flags(dev, flags, extack);
8626 	if (ret < 0)
8627 		return ret;
8628 
8629 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8630 	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
8631 	return ret;
8632 }
8633 EXPORT_SYMBOL(dev_change_flags);
8634 
8635 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8636 {
8637 	const struct net_device_ops *ops = dev->netdev_ops;
8638 
8639 	if (ops->ndo_change_mtu)
8640 		return ops->ndo_change_mtu(dev, new_mtu);
8641 
8642 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8643 	WRITE_ONCE(dev->mtu, new_mtu);
8644 	return 0;
8645 }
8646 EXPORT_SYMBOL(__dev_set_mtu);
8647 
8648 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8649 		     struct netlink_ext_ack *extack)
8650 {
8651 	/* MTU must be positive, and in range */
8652 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8653 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8654 		return -EINVAL;
8655 	}
8656 
8657 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8658 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8659 		return -EINVAL;
8660 	}
8661 	return 0;
8662 }
8663 
8664 /**
8665  *	dev_set_mtu_ext - Change maximum transfer unit
8666  *	@dev: device
8667  *	@new_mtu: new transfer unit
8668  *	@extack: netlink extended ack
8669  *
8670  *	Change the maximum transfer size of the network device.
8671  */
8672 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8673 		    struct netlink_ext_ack *extack)
8674 {
8675 	int err, orig_mtu;
8676 
8677 	if (new_mtu == dev->mtu)
8678 		return 0;
8679 
8680 	err = dev_validate_mtu(dev, new_mtu, extack);
8681 	if (err)
8682 		return err;
8683 
8684 	if (!netif_device_present(dev))
8685 		return -ENODEV;
8686 
8687 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8688 	err = notifier_to_errno(err);
8689 	if (err)
8690 		return err;
8691 
8692 	orig_mtu = dev->mtu;
8693 	err = __dev_set_mtu(dev, new_mtu);
8694 
8695 	if (!err) {
8696 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8697 						   orig_mtu);
8698 		err = notifier_to_errno(err);
8699 		if (err) {
8700 			/* setting mtu back and notifying everyone again,
8701 			 * so that they have a chance to revert changes.
8702 			 */
8703 			__dev_set_mtu(dev, orig_mtu);
8704 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8705 						     new_mtu);
8706 		}
8707 	}
8708 	return err;
8709 }
8710 
8711 int dev_set_mtu(struct net_device *dev, int new_mtu)
8712 {
8713 	struct netlink_ext_ack extack;
8714 	int err;
8715 
8716 	memset(&extack, 0, sizeof(extack));
8717 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
8718 	if (err && extack._msg)
8719 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8720 	return err;
8721 }
8722 EXPORT_SYMBOL(dev_set_mtu);
8723 
8724 /**
8725  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
8726  *	@dev: device
8727  *	@new_len: new tx queue length
8728  */
8729 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8730 {
8731 	unsigned int orig_len = dev->tx_queue_len;
8732 	int res;
8733 
8734 	if (new_len != (unsigned int)new_len)
8735 		return -ERANGE;
8736 
8737 	if (new_len != orig_len) {
8738 		dev->tx_queue_len = new_len;
8739 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8740 		res = notifier_to_errno(res);
8741 		if (res)
8742 			goto err_rollback;
8743 		res = dev_qdisc_change_tx_queue_len(dev);
8744 		if (res)
8745 			goto err_rollback;
8746 	}
8747 
8748 	return 0;
8749 
8750 err_rollback:
8751 	netdev_err(dev, "refused to change device tx_queue_len\n");
8752 	dev->tx_queue_len = orig_len;
8753 	return res;
8754 }
8755 
8756 /**
8757  *	dev_set_group - Change group this device belongs to
8758  *	@dev: device
8759  *	@new_group: group this device should belong to
8760  */
8761 void dev_set_group(struct net_device *dev, int new_group)
8762 {
8763 	dev->group = new_group;
8764 }
8765 
8766 /**
8767  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8768  *	@dev: device
8769  *	@addr: new address
8770  *	@extack: netlink extended ack
8771  */
8772 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8773 			      struct netlink_ext_ack *extack)
8774 {
8775 	struct netdev_notifier_pre_changeaddr_info info = {
8776 		.info.dev = dev,
8777 		.info.extack = extack,
8778 		.dev_addr = addr,
8779 	};
8780 	int rc;
8781 
8782 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8783 	return notifier_to_errno(rc);
8784 }
8785 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8786 
8787 /**
8788  *	dev_set_mac_address - Change Media Access Control Address
8789  *	@dev: device
8790  *	@sa: new address
8791  *	@extack: netlink extended ack
8792  *
8793  *	Change the hardware (MAC) address of the device
8794  */
8795 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8796 			struct netlink_ext_ack *extack)
8797 {
8798 	const struct net_device_ops *ops = dev->netdev_ops;
8799 	int err;
8800 
8801 	if (!ops->ndo_set_mac_address)
8802 		return -EOPNOTSUPP;
8803 	if (sa->sa_family != dev->type)
8804 		return -EINVAL;
8805 	if (!netif_device_present(dev))
8806 		return -ENODEV;
8807 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8808 	if (err)
8809 		return err;
8810 	err = ops->ndo_set_mac_address(dev, sa);
8811 	if (err)
8812 		return err;
8813 	dev->addr_assign_type = NET_ADDR_SET;
8814 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8815 	add_device_randomness(dev->dev_addr, dev->addr_len);
8816 	return 0;
8817 }
8818 EXPORT_SYMBOL(dev_set_mac_address);
8819 
8820 static DECLARE_RWSEM(dev_addr_sem);
8821 
8822 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8823 			     struct netlink_ext_ack *extack)
8824 {
8825 	int ret;
8826 
8827 	down_write(&dev_addr_sem);
8828 	ret = dev_set_mac_address(dev, sa, extack);
8829 	up_write(&dev_addr_sem);
8830 	return ret;
8831 }
8832 EXPORT_SYMBOL(dev_set_mac_address_user);
8833 
8834 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8835 {
8836 	size_t size = sizeof(sa->sa_data_min);
8837 	struct net_device *dev;
8838 	int ret = 0;
8839 
8840 	down_read(&dev_addr_sem);
8841 	rcu_read_lock();
8842 
8843 	dev = dev_get_by_name_rcu(net, dev_name);
8844 	if (!dev) {
8845 		ret = -ENODEV;
8846 		goto unlock;
8847 	}
8848 	if (!dev->addr_len)
8849 		memset(sa->sa_data, 0, size);
8850 	else
8851 		memcpy(sa->sa_data, dev->dev_addr,
8852 		       min_t(size_t, size, dev->addr_len));
8853 	sa->sa_family = dev->type;
8854 
8855 unlock:
8856 	rcu_read_unlock();
8857 	up_read(&dev_addr_sem);
8858 	return ret;
8859 }
8860 EXPORT_SYMBOL(dev_get_mac_address);
8861 
8862 /**
8863  *	dev_change_carrier - Change device carrier
8864  *	@dev: device
8865  *	@new_carrier: new value
8866  *
8867  *	Change device carrier
8868  */
8869 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8870 {
8871 	const struct net_device_ops *ops = dev->netdev_ops;
8872 
8873 	if (!ops->ndo_change_carrier)
8874 		return -EOPNOTSUPP;
8875 	if (!netif_device_present(dev))
8876 		return -ENODEV;
8877 	return ops->ndo_change_carrier(dev, new_carrier);
8878 }
8879 
8880 /**
8881  *	dev_get_phys_port_id - Get device physical port ID
8882  *	@dev: device
8883  *	@ppid: port ID
8884  *
8885  *	Get device physical port ID
8886  */
8887 int dev_get_phys_port_id(struct net_device *dev,
8888 			 struct netdev_phys_item_id *ppid)
8889 {
8890 	const struct net_device_ops *ops = dev->netdev_ops;
8891 
8892 	if (!ops->ndo_get_phys_port_id)
8893 		return -EOPNOTSUPP;
8894 	return ops->ndo_get_phys_port_id(dev, ppid);
8895 }
8896 
8897 /**
8898  *	dev_get_phys_port_name - Get device physical port name
8899  *	@dev: device
8900  *	@name: port name
8901  *	@len: limit of bytes to copy to name
8902  *
8903  *	Get device physical port name
8904  */
8905 int dev_get_phys_port_name(struct net_device *dev,
8906 			   char *name, size_t len)
8907 {
8908 	const struct net_device_ops *ops = dev->netdev_ops;
8909 	int err;
8910 
8911 	if (ops->ndo_get_phys_port_name) {
8912 		err = ops->ndo_get_phys_port_name(dev, name, len);
8913 		if (err != -EOPNOTSUPP)
8914 			return err;
8915 	}
8916 	return devlink_compat_phys_port_name_get(dev, name, len);
8917 }
8918 
8919 /**
8920  *	dev_get_port_parent_id - Get the device's port parent identifier
8921  *	@dev: network device
8922  *	@ppid: pointer to a storage for the port's parent identifier
8923  *	@recurse: allow/disallow recursion to lower devices
8924  *
8925  *	Get the devices's port parent identifier
8926  */
8927 int dev_get_port_parent_id(struct net_device *dev,
8928 			   struct netdev_phys_item_id *ppid,
8929 			   bool recurse)
8930 {
8931 	const struct net_device_ops *ops = dev->netdev_ops;
8932 	struct netdev_phys_item_id first = { };
8933 	struct net_device *lower_dev;
8934 	struct list_head *iter;
8935 	int err;
8936 
8937 	if (ops->ndo_get_port_parent_id) {
8938 		err = ops->ndo_get_port_parent_id(dev, ppid);
8939 		if (err != -EOPNOTSUPP)
8940 			return err;
8941 	}
8942 
8943 	err = devlink_compat_switch_id_get(dev, ppid);
8944 	if (!recurse || err != -EOPNOTSUPP)
8945 		return err;
8946 
8947 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
8948 		err = dev_get_port_parent_id(lower_dev, ppid, true);
8949 		if (err)
8950 			break;
8951 		if (!first.id_len)
8952 			first = *ppid;
8953 		else if (memcmp(&first, ppid, sizeof(*ppid)))
8954 			return -EOPNOTSUPP;
8955 	}
8956 
8957 	return err;
8958 }
8959 EXPORT_SYMBOL(dev_get_port_parent_id);
8960 
8961 /**
8962  *	netdev_port_same_parent_id - Indicate if two network devices have
8963  *	the same port parent identifier
8964  *	@a: first network device
8965  *	@b: second network device
8966  */
8967 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
8968 {
8969 	struct netdev_phys_item_id a_id = { };
8970 	struct netdev_phys_item_id b_id = { };
8971 
8972 	if (dev_get_port_parent_id(a, &a_id, true) ||
8973 	    dev_get_port_parent_id(b, &b_id, true))
8974 		return false;
8975 
8976 	return netdev_phys_item_id_same(&a_id, &b_id);
8977 }
8978 EXPORT_SYMBOL(netdev_port_same_parent_id);
8979 
8980 /**
8981  *	dev_change_proto_down - set carrier according to proto_down.
8982  *
8983  *	@dev: device
8984  *	@proto_down: new value
8985  */
8986 int dev_change_proto_down(struct net_device *dev, bool proto_down)
8987 {
8988 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
8989 		return -EOPNOTSUPP;
8990 	if (!netif_device_present(dev))
8991 		return -ENODEV;
8992 	if (proto_down)
8993 		netif_carrier_off(dev);
8994 	else
8995 		netif_carrier_on(dev);
8996 	dev->proto_down = proto_down;
8997 	return 0;
8998 }
8999 
9000 /**
9001  *	dev_change_proto_down_reason - proto down reason
9002  *
9003  *	@dev: device
9004  *	@mask: proto down mask
9005  *	@value: proto down value
9006  */
9007 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9008 				  u32 value)
9009 {
9010 	int b;
9011 
9012 	if (!mask) {
9013 		dev->proto_down_reason = value;
9014 	} else {
9015 		for_each_set_bit(b, &mask, 32) {
9016 			if (value & (1 << b))
9017 				dev->proto_down_reason |= BIT(b);
9018 			else
9019 				dev->proto_down_reason &= ~BIT(b);
9020 		}
9021 	}
9022 }
9023 
9024 struct bpf_xdp_link {
9025 	struct bpf_link link;
9026 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9027 	int flags;
9028 };
9029 
9030 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9031 {
9032 	if (flags & XDP_FLAGS_HW_MODE)
9033 		return XDP_MODE_HW;
9034 	if (flags & XDP_FLAGS_DRV_MODE)
9035 		return XDP_MODE_DRV;
9036 	if (flags & XDP_FLAGS_SKB_MODE)
9037 		return XDP_MODE_SKB;
9038 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9039 }
9040 
9041 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9042 {
9043 	switch (mode) {
9044 	case XDP_MODE_SKB:
9045 		return generic_xdp_install;
9046 	case XDP_MODE_DRV:
9047 	case XDP_MODE_HW:
9048 		return dev->netdev_ops->ndo_bpf;
9049 	default:
9050 		return NULL;
9051 	}
9052 }
9053 
9054 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9055 					 enum bpf_xdp_mode mode)
9056 {
9057 	return dev->xdp_state[mode].link;
9058 }
9059 
9060 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9061 				     enum bpf_xdp_mode mode)
9062 {
9063 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9064 
9065 	if (link)
9066 		return link->link.prog;
9067 	return dev->xdp_state[mode].prog;
9068 }
9069 
9070 u8 dev_xdp_prog_count(struct net_device *dev)
9071 {
9072 	u8 count = 0;
9073 	int i;
9074 
9075 	for (i = 0; i < __MAX_XDP_MODE; i++)
9076 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9077 			count++;
9078 	return count;
9079 }
9080 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9081 
9082 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9083 {
9084 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9085 
9086 	return prog ? prog->aux->id : 0;
9087 }
9088 
9089 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9090 			     struct bpf_xdp_link *link)
9091 {
9092 	dev->xdp_state[mode].link = link;
9093 	dev->xdp_state[mode].prog = NULL;
9094 }
9095 
9096 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9097 			     struct bpf_prog *prog)
9098 {
9099 	dev->xdp_state[mode].link = NULL;
9100 	dev->xdp_state[mode].prog = prog;
9101 }
9102 
9103 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9104 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9105 			   u32 flags, struct bpf_prog *prog)
9106 {
9107 	struct netdev_bpf xdp;
9108 	int err;
9109 
9110 	memset(&xdp, 0, sizeof(xdp));
9111 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9112 	xdp.extack = extack;
9113 	xdp.flags = flags;
9114 	xdp.prog = prog;
9115 
9116 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9117 	 * "moved" into driver), so they don't increment it on their own, but
9118 	 * they do decrement refcnt when program is detached or replaced.
9119 	 * Given net_device also owns link/prog, we need to bump refcnt here
9120 	 * to prevent drivers from underflowing it.
9121 	 */
9122 	if (prog)
9123 		bpf_prog_inc(prog);
9124 	err = bpf_op(dev, &xdp);
9125 	if (err) {
9126 		if (prog)
9127 			bpf_prog_put(prog);
9128 		return err;
9129 	}
9130 
9131 	if (mode != XDP_MODE_HW)
9132 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9133 
9134 	return 0;
9135 }
9136 
9137 static void dev_xdp_uninstall(struct net_device *dev)
9138 {
9139 	struct bpf_xdp_link *link;
9140 	struct bpf_prog *prog;
9141 	enum bpf_xdp_mode mode;
9142 	bpf_op_t bpf_op;
9143 
9144 	ASSERT_RTNL();
9145 
9146 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9147 		prog = dev_xdp_prog(dev, mode);
9148 		if (!prog)
9149 			continue;
9150 
9151 		bpf_op = dev_xdp_bpf_op(dev, mode);
9152 		if (!bpf_op)
9153 			continue;
9154 
9155 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9156 
9157 		/* auto-detach link from net device */
9158 		link = dev_xdp_link(dev, mode);
9159 		if (link)
9160 			link->dev = NULL;
9161 		else
9162 			bpf_prog_put(prog);
9163 
9164 		dev_xdp_set_link(dev, mode, NULL);
9165 	}
9166 }
9167 
9168 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9169 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9170 			  struct bpf_prog *old_prog, u32 flags)
9171 {
9172 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9173 	struct bpf_prog *cur_prog;
9174 	struct net_device *upper;
9175 	struct list_head *iter;
9176 	enum bpf_xdp_mode mode;
9177 	bpf_op_t bpf_op;
9178 	int err;
9179 
9180 	ASSERT_RTNL();
9181 
9182 	/* either link or prog attachment, never both */
9183 	if (link && (new_prog || old_prog))
9184 		return -EINVAL;
9185 	/* link supports only XDP mode flags */
9186 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9187 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9188 		return -EINVAL;
9189 	}
9190 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9191 	if (num_modes > 1) {
9192 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9193 		return -EINVAL;
9194 	}
9195 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9196 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9197 		NL_SET_ERR_MSG(extack,
9198 			       "More than one program loaded, unset mode is ambiguous");
9199 		return -EINVAL;
9200 	}
9201 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9202 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9203 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9204 		return -EINVAL;
9205 	}
9206 
9207 	mode = dev_xdp_mode(dev, flags);
9208 	/* can't replace attached link */
9209 	if (dev_xdp_link(dev, mode)) {
9210 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9211 		return -EBUSY;
9212 	}
9213 
9214 	/* don't allow if an upper device already has a program */
9215 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9216 		if (dev_xdp_prog_count(upper) > 0) {
9217 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9218 			return -EEXIST;
9219 		}
9220 	}
9221 
9222 	cur_prog = dev_xdp_prog(dev, mode);
9223 	/* can't replace attached prog with link */
9224 	if (link && cur_prog) {
9225 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9226 		return -EBUSY;
9227 	}
9228 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9229 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9230 		return -EEXIST;
9231 	}
9232 
9233 	/* put effective new program into new_prog */
9234 	if (link)
9235 		new_prog = link->link.prog;
9236 
9237 	if (new_prog) {
9238 		bool offload = mode == XDP_MODE_HW;
9239 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9240 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9241 
9242 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9243 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9244 			return -EBUSY;
9245 		}
9246 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9247 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9248 			return -EEXIST;
9249 		}
9250 		if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
9251 			NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
9252 			return -EINVAL;
9253 		}
9254 		if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
9255 			NL_SET_ERR_MSG(extack, "Program bound to different device");
9256 			return -EINVAL;
9257 		}
9258 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9259 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9260 			return -EINVAL;
9261 		}
9262 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9263 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9264 			return -EINVAL;
9265 		}
9266 	}
9267 
9268 	/* don't call drivers if the effective program didn't change */
9269 	if (new_prog != cur_prog) {
9270 		bpf_op = dev_xdp_bpf_op(dev, mode);
9271 		if (!bpf_op) {
9272 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9273 			return -EOPNOTSUPP;
9274 		}
9275 
9276 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9277 		if (err)
9278 			return err;
9279 	}
9280 
9281 	if (link)
9282 		dev_xdp_set_link(dev, mode, link);
9283 	else
9284 		dev_xdp_set_prog(dev, mode, new_prog);
9285 	if (cur_prog)
9286 		bpf_prog_put(cur_prog);
9287 
9288 	return 0;
9289 }
9290 
9291 static int dev_xdp_attach_link(struct net_device *dev,
9292 			       struct netlink_ext_ack *extack,
9293 			       struct bpf_xdp_link *link)
9294 {
9295 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9296 }
9297 
9298 static int dev_xdp_detach_link(struct net_device *dev,
9299 			       struct netlink_ext_ack *extack,
9300 			       struct bpf_xdp_link *link)
9301 {
9302 	enum bpf_xdp_mode mode;
9303 	bpf_op_t bpf_op;
9304 
9305 	ASSERT_RTNL();
9306 
9307 	mode = dev_xdp_mode(dev, link->flags);
9308 	if (dev_xdp_link(dev, mode) != link)
9309 		return -EINVAL;
9310 
9311 	bpf_op = dev_xdp_bpf_op(dev, mode);
9312 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9313 	dev_xdp_set_link(dev, mode, NULL);
9314 	return 0;
9315 }
9316 
9317 static void bpf_xdp_link_release(struct bpf_link *link)
9318 {
9319 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9320 
9321 	rtnl_lock();
9322 
9323 	/* if racing with net_device's tear down, xdp_link->dev might be
9324 	 * already NULL, in which case link was already auto-detached
9325 	 */
9326 	if (xdp_link->dev) {
9327 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9328 		xdp_link->dev = NULL;
9329 	}
9330 
9331 	rtnl_unlock();
9332 }
9333 
9334 static int bpf_xdp_link_detach(struct bpf_link *link)
9335 {
9336 	bpf_xdp_link_release(link);
9337 	return 0;
9338 }
9339 
9340 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9341 {
9342 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9343 
9344 	kfree(xdp_link);
9345 }
9346 
9347 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9348 				     struct seq_file *seq)
9349 {
9350 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9351 	u32 ifindex = 0;
9352 
9353 	rtnl_lock();
9354 	if (xdp_link->dev)
9355 		ifindex = xdp_link->dev->ifindex;
9356 	rtnl_unlock();
9357 
9358 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9359 }
9360 
9361 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9362 				       struct bpf_link_info *info)
9363 {
9364 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9365 	u32 ifindex = 0;
9366 
9367 	rtnl_lock();
9368 	if (xdp_link->dev)
9369 		ifindex = xdp_link->dev->ifindex;
9370 	rtnl_unlock();
9371 
9372 	info->xdp.ifindex = ifindex;
9373 	return 0;
9374 }
9375 
9376 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9377 			       struct bpf_prog *old_prog)
9378 {
9379 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9380 	enum bpf_xdp_mode mode;
9381 	bpf_op_t bpf_op;
9382 	int err = 0;
9383 
9384 	rtnl_lock();
9385 
9386 	/* link might have been auto-released already, so fail */
9387 	if (!xdp_link->dev) {
9388 		err = -ENOLINK;
9389 		goto out_unlock;
9390 	}
9391 
9392 	if (old_prog && link->prog != old_prog) {
9393 		err = -EPERM;
9394 		goto out_unlock;
9395 	}
9396 	old_prog = link->prog;
9397 	if (old_prog->type != new_prog->type ||
9398 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9399 		err = -EINVAL;
9400 		goto out_unlock;
9401 	}
9402 
9403 	if (old_prog == new_prog) {
9404 		/* no-op, don't disturb drivers */
9405 		bpf_prog_put(new_prog);
9406 		goto out_unlock;
9407 	}
9408 
9409 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9410 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9411 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9412 			      xdp_link->flags, new_prog);
9413 	if (err)
9414 		goto out_unlock;
9415 
9416 	old_prog = xchg(&link->prog, new_prog);
9417 	bpf_prog_put(old_prog);
9418 
9419 out_unlock:
9420 	rtnl_unlock();
9421 	return err;
9422 }
9423 
9424 static const struct bpf_link_ops bpf_xdp_link_lops = {
9425 	.release = bpf_xdp_link_release,
9426 	.dealloc = bpf_xdp_link_dealloc,
9427 	.detach = bpf_xdp_link_detach,
9428 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9429 	.fill_link_info = bpf_xdp_link_fill_link_info,
9430 	.update_prog = bpf_xdp_link_update,
9431 };
9432 
9433 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9434 {
9435 	struct net *net = current->nsproxy->net_ns;
9436 	struct bpf_link_primer link_primer;
9437 	struct bpf_xdp_link *link;
9438 	struct net_device *dev;
9439 	int err, fd;
9440 
9441 	rtnl_lock();
9442 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9443 	if (!dev) {
9444 		rtnl_unlock();
9445 		return -EINVAL;
9446 	}
9447 
9448 	link = kzalloc(sizeof(*link), GFP_USER);
9449 	if (!link) {
9450 		err = -ENOMEM;
9451 		goto unlock;
9452 	}
9453 
9454 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9455 	link->dev = dev;
9456 	link->flags = attr->link_create.flags;
9457 
9458 	err = bpf_link_prime(&link->link, &link_primer);
9459 	if (err) {
9460 		kfree(link);
9461 		goto unlock;
9462 	}
9463 
9464 	err = dev_xdp_attach_link(dev, NULL, link);
9465 	rtnl_unlock();
9466 
9467 	if (err) {
9468 		link->dev = NULL;
9469 		bpf_link_cleanup(&link_primer);
9470 		goto out_put_dev;
9471 	}
9472 
9473 	fd = bpf_link_settle(&link_primer);
9474 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9475 	dev_put(dev);
9476 	return fd;
9477 
9478 unlock:
9479 	rtnl_unlock();
9480 
9481 out_put_dev:
9482 	dev_put(dev);
9483 	return err;
9484 }
9485 
9486 /**
9487  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9488  *	@dev: device
9489  *	@extack: netlink extended ack
9490  *	@fd: new program fd or negative value to clear
9491  *	@expected_fd: old program fd that userspace expects to replace or clear
9492  *	@flags: xdp-related flags
9493  *
9494  *	Set or clear a bpf program for a device
9495  */
9496 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9497 		      int fd, int expected_fd, u32 flags)
9498 {
9499 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9500 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9501 	int err;
9502 
9503 	ASSERT_RTNL();
9504 
9505 	if (fd >= 0) {
9506 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9507 						 mode != XDP_MODE_SKB);
9508 		if (IS_ERR(new_prog))
9509 			return PTR_ERR(new_prog);
9510 	}
9511 
9512 	if (expected_fd >= 0) {
9513 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9514 						 mode != XDP_MODE_SKB);
9515 		if (IS_ERR(old_prog)) {
9516 			err = PTR_ERR(old_prog);
9517 			old_prog = NULL;
9518 			goto err_out;
9519 		}
9520 	}
9521 
9522 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9523 
9524 err_out:
9525 	if (err && new_prog)
9526 		bpf_prog_put(new_prog);
9527 	if (old_prog)
9528 		bpf_prog_put(old_prog);
9529 	return err;
9530 }
9531 
9532 /**
9533  *	dev_new_index	-	allocate an ifindex
9534  *	@net: the applicable net namespace
9535  *
9536  *	Returns a suitable unique value for a new device interface
9537  *	number.  The caller must hold the rtnl semaphore or the
9538  *	dev_base_lock to be sure it remains unique.
9539  */
9540 static int dev_new_index(struct net *net)
9541 {
9542 	int ifindex = net->ifindex;
9543 
9544 	for (;;) {
9545 		if (++ifindex <= 0)
9546 			ifindex = 1;
9547 		if (!__dev_get_by_index(net, ifindex))
9548 			return net->ifindex = ifindex;
9549 	}
9550 }
9551 
9552 /* Delayed registration/unregisteration */
9553 LIST_HEAD(net_todo_list);
9554 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9555 
9556 static void net_set_todo(struct net_device *dev)
9557 {
9558 	list_add_tail(&dev->todo_list, &net_todo_list);
9559 	atomic_inc(&dev_net(dev)->dev_unreg_count);
9560 }
9561 
9562 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9563 	struct net_device *upper, netdev_features_t features)
9564 {
9565 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9566 	netdev_features_t feature;
9567 	int feature_bit;
9568 
9569 	for_each_netdev_feature(upper_disables, feature_bit) {
9570 		feature = __NETIF_F_BIT(feature_bit);
9571 		if (!(upper->wanted_features & feature)
9572 		    && (features & feature)) {
9573 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9574 				   &feature, upper->name);
9575 			features &= ~feature;
9576 		}
9577 	}
9578 
9579 	return features;
9580 }
9581 
9582 static void netdev_sync_lower_features(struct net_device *upper,
9583 	struct net_device *lower, netdev_features_t features)
9584 {
9585 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9586 	netdev_features_t feature;
9587 	int feature_bit;
9588 
9589 	for_each_netdev_feature(upper_disables, feature_bit) {
9590 		feature = __NETIF_F_BIT(feature_bit);
9591 		if (!(features & feature) && (lower->features & feature)) {
9592 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9593 				   &feature, lower->name);
9594 			lower->wanted_features &= ~feature;
9595 			__netdev_update_features(lower);
9596 
9597 			if (unlikely(lower->features & feature))
9598 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9599 					    &feature, lower->name);
9600 			else
9601 				netdev_features_change(lower);
9602 		}
9603 	}
9604 }
9605 
9606 static netdev_features_t netdev_fix_features(struct net_device *dev,
9607 	netdev_features_t features)
9608 {
9609 	/* Fix illegal checksum combinations */
9610 	if ((features & NETIF_F_HW_CSUM) &&
9611 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9612 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9613 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9614 	}
9615 
9616 	/* TSO requires that SG is present as well. */
9617 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9618 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9619 		features &= ~NETIF_F_ALL_TSO;
9620 	}
9621 
9622 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9623 					!(features & NETIF_F_IP_CSUM)) {
9624 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9625 		features &= ~NETIF_F_TSO;
9626 		features &= ~NETIF_F_TSO_ECN;
9627 	}
9628 
9629 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9630 					 !(features & NETIF_F_IPV6_CSUM)) {
9631 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9632 		features &= ~NETIF_F_TSO6;
9633 	}
9634 
9635 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9636 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9637 		features &= ~NETIF_F_TSO_MANGLEID;
9638 
9639 	/* TSO ECN requires that TSO is present as well. */
9640 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9641 		features &= ~NETIF_F_TSO_ECN;
9642 
9643 	/* Software GSO depends on SG. */
9644 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9645 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9646 		features &= ~NETIF_F_GSO;
9647 	}
9648 
9649 	/* GSO partial features require GSO partial be set */
9650 	if ((features & dev->gso_partial_features) &&
9651 	    !(features & NETIF_F_GSO_PARTIAL)) {
9652 		netdev_dbg(dev,
9653 			   "Dropping partially supported GSO features since no GSO partial.\n");
9654 		features &= ~dev->gso_partial_features;
9655 	}
9656 
9657 	if (!(features & NETIF_F_RXCSUM)) {
9658 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9659 		 * successfully merged by hardware must also have the
9660 		 * checksum verified by hardware.  If the user does not
9661 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9662 		 */
9663 		if (features & NETIF_F_GRO_HW) {
9664 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9665 			features &= ~NETIF_F_GRO_HW;
9666 		}
9667 	}
9668 
9669 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9670 	if (features & NETIF_F_RXFCS) {
9671 		if (features & NETIF_F_LRO) {
9672 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9673 			features &= ~NETIF_F_LRO;
9674 		}
9675 
9676 		if (features & NETIF_F_GRO_HW) {
9677 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9678 			features &= ~NETIF_F_GRO_HW;
9679 		}
9680 	}
9681 
9682 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9683 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9684 		features &= ~NETIF_F_LRO;
9685 	}
9686 
9687 	if (features & NETIF_F_HW_TLS_TX) {
9688 		bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9689 			(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9690 		bool hw_csum = features & NETIF_F_HW_CSUM;
9691 
9692 		if (!ip_csum && !hw_csum) {
9693 			netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9694 			features &= ~NETIF_F_HW_TLS_TX;
9695 		}
9696 	}
9697 
9698 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9699 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9700 		features &= ~NETIF_F_HW_TLS_RX;
9701 	}
9702 
9703 	return features;
9704 }
9705 
9706 int __netdev_update_features(struct net_device *dev)
9707 {
9708 	struct net_device *upper, *lower;
9709 	netdev_features_t features;
9710 	struct list_head *iter;
9711 	int err = -1;
9712 
9713 	ASSERT_RTNL();
9714 
9715 	features = netdev_get_wanted_features(dev);
9716 
9717 	if (dev->netdev_ops->ndo_fix_features)
9718 		features = dev->netdev_ops->ndo_fix_features(dev, features);
9719 
9720 	/* driver might be less strict about feature dependencies */
9721 	features = netdev_fix_features(dev, features);
9722 
9723 	/* some features can't be enabled if they're off on an upper device */
9724 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
9725 		features = netdev_sync_upper_features(dev, upper, features);
9726 
9727 	if (dev->features == features)
9728 		goto sync_lower;
9729 
9730 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9731 		&dev->features, &features);
9732 
9733 	if (dev->netdev_ops->ndo_set_features)
9734 		err = dev->netdev_ops->ndo_set_features(dev, features);
9735 	else
9736 		err = 0;
9737 
9738 	if (unlikely(err < 0)) {
9739 		netdev_err(dev,
9740 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
9741 			err, &features, &dev->features);
9742 		/* return non-0 since some features might have changed and
9743 		 * it's better to fire a spurious notification than miss it
9744 		 */
9745 		return -1;
9746 	}
9747 
9748 sync_lower:
9749 	/* some features must be disabled on lower devices when disabled
9750 	 * on an upper device (think: bonding master or bridge)
9751 	 */
9752 	netdev_for_each_lower_dev(dev, lower, iter)
9753 		netdev_sync_lower_features(dev, lower, features);
9754 
9755 	if (!err) {
9756 		netdev_features_t diff = features ^ dev->features;
9757 
9758 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9759 			/* udp_tunnel_{get,drop}_rx_info both need
9760 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9761 			 * device, or they won't do anything.
9762 			 * Thus we need to update dev->features
9763 			 * *before* calling udp_tunnel_get_rx_info,
9764 			 * but *after* calling udp_tunnel_drop_rx_info.
9765 			 */
9766 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9767 				dev->features = features;
9768 				udp_tunnel_get_rx_info(dev);
9769 			} else {
9770 				udp_tunnel_drop_rx_info(dev);
9771 			}
9772 		}
9773 
9774 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9775 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9776 				dev->features = features;
9777 				err |= vlan_get_rx_ctag_filter_info(dev);
9778 			} else {
9779 				vlan_drop_rx_ctag_filter_info(dev);
9780 			}
9781 		}
9782 
9783 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9784 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9785 				dev->features = features;
9786 				err |= vlan_get_rx_stag_filter_info(dev);
9787 			} else {
9788 				vlan_drop_rx_stag_filter_info(dev);
9789 			}
9790 		}
9791 
9792 		dev->features = features;
9793 	}
9794 
9795 	return err < 0 ? 0 : 1;
9796 }
9797 
9798 /**
9799  *	netdev_update_features - recalculate device features
9800  *	@dev: the device to check
9801  *
9802  *	Recalculate dev->features set and send notifications if it
9803  *	has changed. Should be called after driver or hardware dependent
9804  *	conditions might have changed that influence the features.
9805  */
9806 void netdev_update_features(struct net_device *dev)
9807 {
9808 	if (__netdev_update_features(dev))
9809 		netdev_features_change(dev);
9810 }
9811 EXPORT_SYMBOL(netdev_update_features);
9812 
9813 /**
9814  *	netdev_change_features - recalculate device features
9815  *	@dev: the device to check
9816  *
9817  *	Recalculate dev->features set and send notifications even
9818  *	if they have not changed. Should be called instead of
9819  *	netdev_update_features() if also dev->vlan_features might
9820  *	have changed to allow the changes to be propagated to stacked
9821  *	VLAN devices.
9822  */
9823 void netdev_change_features(struct net_device *dev)
9824 {
9825 	__netdev_update_features(dev);
9826 	netdev_features_change(dev);
9827 }
9828 EXPORT_SYMBOL(netdev_change_features);
9829 
9830 /**
9831  *	netif_stacked_transfer_operstate -	transfer operstate
9832  *	@rootdev: the root or lower level device to transfer state from
9833  *	@dev: the device to transfer operstate to
9834  *
9835  *	Transfer operational state from root to device. This is normally
9836  *	called when a stacking relationship exists between the root
9837  *	device and the device(a leaf device).
9838  */
9839 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9840 					struct net_device *dev)
9841 {
9842 	if (rootdev->operstate == IF_OPER_DORMANT)
9843 		netif_dormant_on(dev);
9844 	else
9845 		netif_dormant_off(dev);
9846 
9847 	if (rootdev->operstate == IF_OPER_TESTING)
9848 		netif_testing_on(dev);
9849 	else
9850 		netif_testing_off(dev);
9851 
9852 	if (netif_carrier_ok(rootdev))
9853 		netif_carrier_on(dev);
9854 	else
9855 		netif_carrier_off(dev);
9856 }
9857 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9858 
9859 static int netif_alloc_rx_queues(struct net_device *dev)
9860 {
9861 	unsigned int i, count = dev->num_rx_queues;
9862 	struct netdev_rx_queue *rx;
9863 	size_t sz = count * sizeof(*rx);
9864 	int err = 0;
9865 
9866 	BUG_ON(count < 1);
9867 
9868 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9869 	if (!rx)
9870 		return -ENOMEM;
9871 
9872 	dev->_rx = rx;
9873 
9874 	for (i = 0; i < count; i++) {
9875 		rx[i].dev = dev;
9876 
9877 		/* XDP RX-queue setup */
9878 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9879 		if (err < 0)
9880 			goto err_rxq_info;
9881 	}
9882 	return 0;
9883 
9884 err_rxq_info:
9885 	/* Rollback successful reg's and free other resources */
9886 	while (i--)
9887 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9888 	kvfree(dev->_rx);
9889 	dev->_rx = NULL;
9890 	return err;
9891 }
9892 
9893 static void netif_free_rx_queues(struct net_device *dev)
9894 {
9895 	unsigned int i, count = dev->num_rx_queues;
9896 
9897 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9898 	if (!dev->_rx)
9899 		return;
9900 
9901 	for (i = 0; i < count; i++)
9902 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9903 
9904 	kvfree(dev->_rx);
9905 }
9906 
9907 static void netdev_init_one_queue(struct net_device *dev,
9908 				  struct netdev_queue *queue, void *_unused)
9909 {
9910 	/* Initialize queue lock */
9911 	spin_lock_init(&queue->_xmit_lock);
9912 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9913 	queue->xmit_lock_owner = -1;
9914 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9915 	queue->dev = dev;
9916 #ifdef CONFIG_BQL
9917 	dql_init(&queue->dql, HZ);
9918 #endif
9919 }
9920 
9921 static void netif_free_tx_queues(struct net_device *dev)
9922 {
9923 	kvfree(dev->_tx);
9924 }
9925 
9926 static int netif_alloc_netdev_queues(struct net_device *dev)
9927 {
9928 	unsigned int count = dev->num_tx_queues;
9929 	struct netdev_queue *tx;
9930 	size_t sz = count * sizeof(*tx);
9931 
9932 	if (count < 1 || count > 0xffff)
9933 		return -EINVAL;
9934 
9935 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9936 	if (!tx)
9937 		return -ENOMEM;
9938 
9939 	dev->_tx = tx;
9940 
9941 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
9942 	spin_lock_init(&dev->tx_global_lock);
9943 
9944 	return 0;
9945 }
9946 
9947 void netif_tx_stop_all_queues(struct net_device *dev)
9948 {
9949 	unsigned int i;
9950 
9951 	for (i = 0; i < dev->num_tx_queues; i++) {
9952 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
9953 
9954 		netif_tx_stop_queue(txq);
9955 	}
9956 }
9957 EXPORT_SYMBOL(netif_tx_stop_all_queues);
9958 
9959 /**
9960  * register_netdevice() - register a network device
9961  * @dev: device to register
9962  *
9963  * Take a prepared network device structure and make it externally accessible.
9964  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
9965  * Callers must hold the rtnl lock - you may want register_netdev()
9966  * instead of this.
9967  */
9968 int register_netdevice(struct net_device *dev)
9969 {
9970 	int ret;
9971 	struct net *net = dev_net(dev);
9972 
9973 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
9974 		     NETDEV_FEATURE_COUNT);
9975 	BUG_ON(dev_boot_phase);
9976 	ASSERT_RTNL();
9977 
9978 	might_sleep();
9979 
9980 	/* When net_device's are persistent, this will be fatal. */
9981 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
9982 	BUG_ON(!net);
9983 
9984 	ret = ethtool_check_ops(dev->ethtool_ops);
9985 	if (ret)
9986 		return ret;
9987 
9988 	spin_lock_init(&dev->addr_list_lock);
9989 	netdev_set_addr_lockdep_class(dev);
9990 
9991 	ret = dev_get_valid_name(net, dev, dev->name);
9992 	if (ret < 0)
9993 		goto out;
9994 
9995 	ret = -ENOMEM;
9996 	dev->name_node = netdev_name_node_head_alloc(dev);
9997 	if (!dev->name_node)
9998 		goto out;
9999 
10000 	/* Init, if this function is available */
10001 	if (dev->netdev_ops->ndo_init) {
10002 		ret = dev->netdev_ops->ndo_init(dev);
10003 		if (ret) {
10004 			if (ret > 0)
10005 				ret = -EIO;
10006 			goto err_free_name;
10007 		}
10008 	}
10009 
10010 	if (((dev->hw_features | dev->features) &
10011 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
10012 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10013 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10014 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10015 		ret = -EINVAL;
10016 		goto err_uninit;
10017 	}
10018 
10019 	ret = -EBUSY;
10020 	if (!dev->ifindex)
10021 		dev->ifindex = dev_new_index(net);
10022 	else if (__dev_get_by_index(net, dev->ifindex))
10023 		goto err_uninit;
10024 
10025 	/* Transfer changeable features to wanted_features and enable
10026 	 * software offloads (GSO and GRO).
10027 	 */
10028 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10029 	dev->features |= NETIF_F_SOFT_FEATURES;
10030 
10031 	if (dev->udp_tunnel_nic_info) {
10032 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10033 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10034 	}
10035 
10036 	dev->wanted_features = dev->features & dev->hw_features;
10037 
10038 	if (!(dev->flags & IFF_LOOPBACK))
10039 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10040 
10041 	/* If IPv4 TCP segmentation offload is supported we should also
10042 	 * allow the device to enable segmenting the frame with the option
10043 	 * of ignoring a static IP ID value.  This doesn't enable the
10044 	 * feature itself but allows the user to enable it later.
10045 	 */
10046 	if (dev->hw_features & NETIF_F_TSO)
10047 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10048 	if (dev->vlan_features & NETIF_F_TSO)
10049 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10050 	if (dev->mpls_features & NETIF_F_TSO)
10051 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10052 	if (dev->hw_enc_features & NETIF_F_TSO)
10053 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10054 
10055 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10056 	 */
10057 	dev->vlan_features |= NETIF_F_HIGHDMA;
10058 
10059 	/* Make NETIF_F_SG inheritable to tunnel devices.
10060 	 */
10061 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10062 
10063 	/* Make NETIF_F_SG inheritable to MPLS.
10064 	 */
10065 	dev->mpls_features |= NETIF_F_SG;
10066 
10067 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10068 	ret = notifier_to_errno(ret);
10069 	if (ret)
10070 		goto err_uninit;
10071 
10072 	ret = netdev_register_kobject(dev);
10073 	write_lock(&dev_base_lock);
10074 	dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10075 	write_unlock(&dev_base_lock);
10076 	if (ret)
10077 		goto err_uninit_notify;
10078 
10079 	__netdev_update_features(dev);
10080 
10081 	/*
10082 	 *	Default initial state at registry is that the
10083 	 *	device is present.
10084 	 */
10085 
10086 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10087 
10088 	linkwatch_init_dev(dev);
10089 
10090 	dev_init_scheduler(dev);
10091 
10092 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10093 	list_netdevice(dev);
10094 
10095 	add_device_randomness(dev->dev_addr, dev->addr_len);
10096 
10097 	/* If the device has permanent device address, driver should
10098 	 * set dev_addr and also addr_assign_type should be set to
10099 	 * NET_ADDR_PERM (default value).
10100 	 */
10101 	if (dev->addr_assign_type == NET_ADDR_PERM)
10102 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10103 
10104 	/* Notify protocols, that a new device appeared. */
10105 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10106 	ret = notifier_to_errno(ret);
10107 	if (ret) {
10108 		/* Expect explicit free_netdev() on failure */
10109 		dev->needs_free_netdev = false;
10110 		unregister_netdevice_queue(dev, NULL);
10111 		goto out;
10112 	}
10113 	/*
10114 	 *	Prevent userspace races by waiting until the network
10115 	 *	device is fully setup before sending notifications.
10116 	 */
10117 	if (!dev->rtnl_link_ops ||
10118 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10119 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10120 
10121 out:
10122 	return ret;
10123 
10124 err_uninit_notify:
10125 	call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10126 err_uninit:
10127 	if (dev->netdev_ops->ndo_uninit)
10128 		dev->netdev_ops->ndo_uninit(dev);
10129 	if (dev->priv_destructor)
10130 		dev->priv_destructor(dev);
10131 err_free_name:
10132 	netdev_name_node_free(dev->name_node);
10133 	goto out;
10134 }
10135 EXPORT_SYMBOL(register_netdevice);
10136 
10137 /**
10138  *	init_dummy_netdev	- init a dummy network device for NAPI
10139  *	@dev: device to init
10140  *
10141  *	This takes a network device structure and initialize the minimum
10142  *	amount of fields so it can be used to schedule NAPI polls without
10143  *	registering a full blown interface. This is to be used by drivers
10144  *	that need to tie several hardware interfaces to a single NAPI
10145  *	poll scheduler due to HW limitations.
10146  */
10147 int init_dummy_netdev(struct net_device *dev)
10148 {
10149 	/* Clear everything. Note we don't initialize spinlocks
10150 	 * are they aren't supposed to be taken by any of the
10151 	 * NAPI code and this dummy netdev is supposed to be
10152 	 * only ever used for NAPI polls
10153 	 */
10154 	memset(dev, 0, sizeof(struct net_device));
10155 
10156 	/* make sure we BUG if trying to hit standard
10157 	 * register/unregister code path
10158 	 */
10159 	dev->reg_state = NETREG_DUMMY;
10160 
10161 	/* NAPI wants this */
10162 	INIT_LIST_HEAD(&dev->napi_list);
10163 
10164 	/* a dummy interface is started by default */
10165 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10166 	set_bit(__LINK_STATE_START, &dev->state);
10167 
10168 	/* napi_busy_loop stats accounting wants this */
10169 	dev_net_set(dev, &init_net);
10170 
10171 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10172 	 * because users of this 'device' dont need to change
10173 	 * its refcount.
10174 	 */
10175 
10176 	return 0;
10177 }
10178 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10179 
10180 
10181 /**
10182  *	register_netdev	- register a network device
10183  *	@dev: device to register
10184  *
10185  *	Take a completed network device structure and add it to the kernel
10186  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10187  *	chain. 0 is returned on success. A negative errno code is returned
10188  *	on a failure to set up the device, or if the name is a duplicate.
10189  *
10190  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10191  *	and expands the device name if you passed a format string to
10192  *	alloc_netdev.
10193  */
10194 int register_netdev(struct net_device *dev)
10195 {
10196 	int err;
10197 
10198 	if (rtnl_lock_killable())
10199 		return -EINTR;
10200 	err = register_netdevice(dev);
10201 	rtnl_unlock();
10202 	return err;
10203 }
10204 EXPORT_SYMBOL(register_netdev);
10205 
10206 int netdev_refcnt_read(const struct net_device *dev)
10207 {
10208 #ifdef CONFIG_PCPU_DEV_REFCNT
10209 	int i, refcnt = 0;
10210 
10211 	for_each_possible_cpu(i)
10212 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10213 	return refcnt;
10214 #else
10215 	return refcount_read(&dev->dev_refcnt);
10216 #endif
10217 }
10218 EXPORT_SYMBOL(netdev_refcnt_read);
10219 
10220 int netdev_unregister_timeout_secs __read_mostly = 10;
10221 
10222 #define WAIT_REFS_MIN_MSECS 1
10223 #define WAIT_REFS_MAX_MSECS 250
10224 /**
10225  * netdev_wait_allrefs_any - wait until all references are gone.
10226  * @list: list of net_devices to wait on
10227  *
10228  * This is called when unregistering network devices.
10229  *
10230  * Any protocol or device that holds a reference should register
10231  * for netdevice notification, and cleanup and put back the
10232  * reference if they receive an UNREGISTER event.
10233  * We can get stuck here if buggy protocols don't correctly
10234  * call dev_put.
10235  */
10236 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10237 {
10238 	unsigned long rebroadcast_time, warning_time;
10239 	struct net_device *dev;
10240 	int wait = 0;
10241 
10242 	rebroadcast_time = warning_time = jiffies;
10243 
10244 	list_for_each_entry(dev, list, todo_list)
10245 		if (netdev_refcnt_read(dev) == 1)
10246 			return dev;
10247 
10248 	while (true) {
10249 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10250 			rtnl_lock();
10251 
10252 			/* Rebroadcast unregister notification */
10253 			list_for_each_entry(dev, list, todo_list)
10254 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10255 
10256 			__rtnl_unlock();
10257 			rcu_barrier();
10258 			rtnl_lock();
10259 
10260 			list_for_each_entry(dev, list, todo_list)
10261 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10262 					     &dev->state)) {
10263 					/* We must not have linkwatch events
10264 					 * pending on unregister. If this
10265 					 * happens, we simply run the queue
10266 					 * unscheduled, resulting in a noop
10267 					 * for this device.
10268 					 */
10269 					linkwatch_run_queue();
10270 					break;
10271 				}
10272 
10273 			__rtnl_unlock();
10274 
10275 			rebroadcast_time = jiffies;
10276 		}
10277 
10278 		if (!wait) {
10279 			rcu_barrier();
10280 			wait = WAIT_REFS_MIN_MSECS;
10281 		} else {
10282 			msleep(wait);
10283 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10284 		}
10285 
10286 		list_for_each_entry(dev, list, todo_list)
10287 			if (netdev_refcnt_read(dev) == 1)
10288 				return dev;
10289 
10290 		if (time_after(jiffies, warning_time +
10291 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10292 			list_for_each_entry(dev, list, todo_list) {
10293 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10294 					 dev->name, netdev_refcnt_read(dev));
10295 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10296 			}
10297 
10298 			warning_time = jiffies;
10299 		}
10300 	}
10301 }
10302 
10303 /* The sequence is:
10304  *
10305  *	rtnl_lock();
10306  *	...
10307  *	register_netdevice(x1);
10308  *	register_netdevice(x2);
10309  *	...
10310  *	unregister_netdevice(y1);
10311  *	unregister_netdevice(y2);
10312  *      ...
10313  *	rtnl_unlock();
10314  *	free_netdev(y1);
10315  *	free_netdev(y2);
10316  *
10317  * We are invoked by rtnl_unlock().
10318  * This allows us to deal with problems:
10319  * 1) We can delete sysfs objects which invoke hotplug
10320  *    without deadlocking with linkwatch via keventd.
10321  * 2) Since we run with the RTNL semaphore not held, we can sleep
10322  *    safely in order to wait for the netdev refcnt to drop to zero.
10323  *
10324  * We must not return until all unregister events added during
10325  * the interval the lock was held have been completed.
10326  */
10327 void netdev_run_todo(void)
10328 {
10329 	struct net_device *dev, *tmp;
10330 	struct list_head list;
10331 #ifdef CONFIG_LOCKDEP
10332 	struct list_head unlink_list;
10333 
10334 	list_replace_init(&net_unlink_list, &unlink_list);
10335 
10336 	while (!list_empty(&unlink_list)) {
10337 		struct net_device *dev = list_first_entry(&unlink_list,
10338 							  struct net_device,
10339 							  unlink_list);
10340 		list_del_init(&dev->unlink_list);
10341 		dev->nested_level = dev->lower_level - 1;
10342 	}
10343 #endif
10344 
10345 	/* Snapshot list, allow later requests */
10346 	list_replace_init(&net_todo_list, &list);
10347 
10348 	__rtnl_unlock();
10349 
10350 	/* Wait for rcu callbacks to finish before next phase */
10351 	if (!list_empty(&list))
10352 		rcu_barrier();
10353 
10354 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10355 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10356 			netdev_WARN(dev, "run_todo but not unregistering\n");
10357 			list_del(&dev->todo_list);
10358 			continue;
10359 		}
10360 
10361 		write_lock(&dev_base_lock);
10362 		dev->reg_state = NETREG_UNREGISTERED;
10363 		write_unlock(&dev_base_lock);
10364 		linkwatch_forget_dev(dev);
10365 	}
10366 
10367 	while (!list_empty(&list)) {
10368 		dev = netdev_wait_allrefs_any(&list);
10369 		list_del(&dev->todo_list);
10370 
10371 		/* paranoia */
10372 		BUG_ON(netdev_refcnt_read(dev) != 1);
10373 		BUG_ON(!list_empty(&dev->ptype_all));
10374 		BUG_ON(!list_empty(&dev->ptype_specific));
10375 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10376 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10377 
10378 		if (dev->priv_destructor)
10379 			dev->priv_destructor(dev);
10380 		if (dev->needs_free_netdev)
10381 			free_netdev(dev);
10382 
10383 		if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10384 			wake_up(&netdev_unregistering_wq);
10385 
10386 		/* Free network device */
10387 		kobject_put(&dev->dev.kobj);
10388 	}
10389 }
10390 
10391 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10392  * all the same fields in the same order as net_device_stats, with only
10393  * the type differing, but rtnl_link_stats64 may have additional fields
10394  * at the end for newer counters.
10395  */
10396 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10397 			     const struct net_device_stats *netdev_stats)
10398 {
10399 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10400 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10401 	u64 *dst = (u64 *)stats64;
10402 
10403 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10404 	for (i = 0; i < n; i++)
10405 		dst[i] = (unsigned long)atomic_long_read(&src[i]);
10406 	/* zero out counters that only exist in rtnl_link_stats64 */
10407 	memset((char *)stats64 + n * sizeof(u64), 0,
10408 	       sizeof(*stats64) - n * sizeof(u64));
10409 }
10410 EXPORT_SYMBOL(netdev_stats_to_stats64);
10411 
10412 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10413 {
10414 	struct net_device_core_stats __percpu *p;
10415 
10416 	p = alloc_percpu_gfp(struct net_device_core_stats,
10417 			     GFP_ATOMIC | __GFP_NOWARN);
10418 
10419 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10420 		free_percpu(p);
10421 
10422 	/* This READ_ONCE() pairs with the cmpxchg() above */
10423 	return READ_ONCE(dev->core_stats);
10424 }
10425 EXPORT_SYMBOL(netdev_core_stats_alloc);
10426 
10427 /**
10428  *	dev_get_stats	- get network device statistics
10429  *	@dev: device to get statistics from
10430  *	@storage: place to store stats
10431  *
10432  *	Get network statistics from device. Return @storage.
10433  *	The device driver may provide its own method by setting
10434  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10435  *	otherwise the internal statistics structure is used.
10436  */
10437 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10438 					struct rtnl_link_stats64 *storage)
10439 {
10440 	const struct net_device_ops *ops = dev->netdev_ops;
10441 	const struct net_device_core_stats __percpu *p;
10442 
10443 	if (ops->ndo_get_stats64) {
10444 		memset(storage, 0, sizeof(*storage));
10445 		ops->ndo_get_stats64(dev, storage);
10446 	} else if (ops->ndo_get_stats) {
10447 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10448 	} else {
10449 		netdev_stats_to_stats64(storage, &dev->stats);
10450 	}
10451 
10452 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10453 	p = READ_ONCE(dev->core_stats);
10454 	if (p) {
10455 		const struct net_device_core_stats *core_stats;
10456 		int i;
10457 
10458 		for_each_possible_cpu(i) {
10459 			core_stats = per_cpu_ptr(p, i);
10460 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10461 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10462 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10463 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10464 		}
10465 	}
10466 	return storage;
10467 }
10468 EXPORT_SYMBOL(dev_get_stats);
10469 
10470 /**
10471  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10472  *	@s: place to store stats
10473  *	@netstats: per-cpu network stats to read from
10474  *
10475  *	Read per-cpu network statistics and populate the related fields in @s.
10476  */
10477 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10478 			   const struct pcpu_sw_netstats __percpu *netstats)
10479 {
10480 	int cpu;
10481 
10482 	for_each_possible_cpu(cpu) {
10483 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10484 		const struct pcpu_sw_netstats *stats;
10485 		unsigned int start;
10486 
10487 		stats = per_cpu_ptr(netstats, cpu);
10488 		do {
10489 			start = u64_stats_fetch_begin(&stats->syncp);
10490 			rx_packets = u64_stats_read(&stats->rx_packets);
10491 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10492 			tx_packets = u64_stats_read(&stats->tx_packets);
10493 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10494 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10495 
10496 		s->rx_packets += rx_packets;
10497 		s->rx_bytes   += rx_bytes;
10498 		s->tx_packets += tx_packets;
10499 		s->tx_bytes   += tx_bytes;
10500 	}
10501 }
10502 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10503 
10504 /**
10505  *	dev_get_tstats64 - ndo_get_stats64 implementation
10506  *	@dev: device to get statistics from
10507  *	@s: place to store stats
10508  *
10509  *	Populate @s from dev->stats and dev->tstats. Can be used as
10510  *	ndo_get_stats64() callback.
10511  */
10512 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10513 {
10514 	netdev_stats_to_stats64(s, &dev->stats);
10515 	dev_fetch_sw_netstats(s, dev->tstats);
10516 }
10517 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10518 
10519 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10520 {
10521 	struct netdev_queue *queue = dev_ingress_queue(dev);
10522 
10523 #ifdef CONFIG_NET_CLS_ACT
10524 	if (queue)
10525 		return queue;
10526 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10527 	if (!queue)
10528 		return NULL;
10529 	netdev_init_one_queue(dev, queue, NULL);
10530 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10531 	queue->qdisc_sleeping = &noop_qdisc;
10532 	rcu_assign_pointer(dev->ingress_queue, queue);
10533 #endif
10534 	return queue;
10535 }
10536 
10537 static const struct ethtool_ops default_ethtool_ops;
10538 
10539 void netdev_set_default_ethtool_ops(struct net_device *dev,
10540 				    const struct ethtool_ops *ops)
10541 {
10542 	if (dev->ethtool_ops == &default_ethtool_ops)
10543 		dev->ethtool_ops = ops;
10544 }
10545 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10546 
10547 /**
10548  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
10549  * @dev: netdev to enable the IRQ coalescing on
10550  *
10551  * Sets a conservative default for SW IRQ coalescing. Users can use
10552  * sysfs attributes to override the default values.
10553  */
10554 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
10555 {
10556 	WARN_ON(dev->reg_state == NETREG_REGISTERED);
10557 
10558 	dev->gro_flush_timeout = 20000;
10559 	dev->napi_defer_hard_irqs = 1;
10560 }
10561 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
10562 
10563 void netdev_freemem(struct net_device *dev)
10564 {
10565 	char *addr = (char *)dev - dev->padded;
10566 
10567 	kvfree(addr);
10568 }
10569 
10570 /**
10571  * alloc_netdev_mqs - allocate network device
10572  * @sizeof_priv: size of private data to allocate space for
10573  * @name: device name format string
10574  * @name_assign_type: origin of device name
10575  * @setup: callback to initialize device
10576  * @txqs: the number of TX subqueues to allocate
10577  * @rxqs: the number of RX subqueues to allocate
10578  *
10579  * Allocates a struct net_device with private data area for driver use
10580  * and performs basic initialization.  Also allocates subqueue structs
10581  * for each queue on the device.
10582  */
10583 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10584 		unsigned char name_assign_type,
10585 		void (*setup)(struct net_device *),
10586 		unsigned int txqs, unsigned int rxqs)
10587 {
10588 	struct net_device *dev;
10589 	unsigned int alloc_size;
10590 	struct net_device *p;
10591 
10592 	BUG_ON(strlen(name) >= sizeof(dev->name));
10593 
10594 	if (txqs < 1) {
10595 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10596 		return NULL;
10597 	}
10598 
10599 	if (rxqs < 1) {
10600 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10601 		return NULL;
10602 	}
10603 
10604 	alloc_size = sizeof(struct net_device);
10605 	if (sizeof_priv) {
10606 		/* ensure 32-byte alignment of private area */
10607 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10608 		alloc_size += sizeof_priv;
10609 	}
10610 	/* ensure 32-byte alignment of whole construct */
10611 	alloc_size += NETDEV_ALIGN - 1;
10612 
10613 	p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10614 	if (!p)
10615 		return NULL;
10616 
10617 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
10618 	dev->padded = (char *)dev - (char *)p;
10619 
10620 	ref_tracker_dir_init(&dev->refcnt_tracker, 128);
10621 #ifdef CONFIG_PCPU_DEV_REFCNT
10622 	dev->pcpu_refcnt = alloc_percpu(int);
10623 	if (!dev->pcpu_refcnt)
10624 		goto free_dev;
10625 	__dev_hold(dev);
10626 #else
10627 	refcount_set(&dev->dev_refcnt, 1);
10628 #endif
10629 
10630 	if (dev_addr_init(dev))
10631 		goto free_pcpu;
10632 
10633 	dev_mc_init(dev);
10634 	dev_uc_init(dev);
10635 
10636 	dev_net_set(dev, &init_net);
10637 
10638 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10639 	dev->gso_max_segs = GSO_MAX_SEGS;
10640 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10641 	dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
10642 	dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
10643 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10644 	dev->tso_max_segs = TSO_MAX_SEGS;
10645 	dev->upper_level = 1;
10646 	dev->lower_level = 1;
10647 #ifdef CONFIG_LOCKDEP
10648 	dev->nested_level = 0;
10649 	INIT_LIST_HEAD(&dev->unlink_list);
10650 #endif
10651 
10652 	INIT_LIST_HEAD(&dev->napi_list);
10653 	INIT_LIST_HEAD(&dev->unreg_list);
10654 	INIT_LIST_HEAD(&dev->close_list);
10655 	INIT_LIST_HEAD(&dev->link_watch_list);
10656 	INIT_LIST_HEAD(&dev->adj_list.upper);
10657 	INIT_LIST_HEAD(&dev->adj_list.lower);
10658 	INIT_LIST_HEAD(&dev->ptype_all);
10659 	INIT_LIST_HEAD(&dev->ptype_specific);
10660 	INIT_LIST_HEAD(&dev->net_notifier_list);
10661 #ifdef CONFIG_NET_SCHED
10662 	hash_init(dev->qdisc_hash);
10663 #endif
10664 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10665 	setup(dev);
10666 
10667 	if (!dev->tx_queue_len) {
10668 		dev->priv_flags |= IFF_NO_QUEUE;
10669 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10670 	}
10671 
10672 	dev->num_tx_queues = txqs;
10673 	dev->real_num_tx_queues = txqs;
10674 	if (netif_alloc_netdev_queues(dev))
10675 		goto free_all;
10676 
10677 	dev->num_rx_queues = rxqs;
10678 	dev->real_num_rx_queues = rxqs;
10679 	if (netif_alloc_rx_queues(dev))
10680 		goto free_all;
10681 
10682 	strcpy(dev->name, name);
10683 	dev->name_assign_type = name_assign_type;
10684 	dev->group = INIT_NETDEV_GROUP;
10685 	if (!dev->ethtool_ops)
10686 		dev->ethtool_ops = &default_ethtool_ops;
10687 
10688 	nf_hook_netdev_init(dev);
10689 
10690 	return dev;
10691 
10692 free_all:
10693 	free_netdev(dev);
10694 	return NULL;
10695 
10696 free_pcpu:
10697 #ifdef CONFIG_PCPU_DEV_REFCNT
10698 	free_percpu(dev->pcpu_refcnt);
10699 free_dev:
10700 #endif
10701 	netdev_freemem(dev);
10702 	return NULL;
10703 }
10704 EXPORT_SYMBOL(alloc_netdev_mqs);
10705 
10706 /**
10707  * free_netdev - free network device
10708  * @dev: device
10709  *
10710  * This function does the last stage of destroying an allocated device
10711  * interface. The reference to the device object is released. If this
10712  * is the last reference then it will be freed.Must be called in process
10713  * context.
10714  */
10715 void free_netdev(struct net_device *dev)
10716 {
10717 	struct napi_struct *p, *n;
10718 
10719 	might_sleep();
10720 
10721 	/* When called immediately after register_netdevice() failed the unwind
10722 	 * handling may still be dismantling the device. Handle that case by
10723 	 * deferring the free.
10724 	 */
10725 	if (dev->reg_state == NETREG_UNREGISTERING) {
10726 		ASSERT_RTNL();
10727 		dev->needs_free_netdev = true;
10728 		return;
10729 	}
10730 
10731 	netif_free_tx_queues(dev);
10732 	netif_free_rx_queues(dev);
10733 
10734 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10735 
10736 	/* Flush device addresses */
10737 	dev_addr_flush(dev);
10738 
10739 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10740 		netif_napi_del(p);
10741 
10742 	ref_tracker_dir_exit(&dev->refcnt_tracker);
10743 #ifdef CONFIG_PCPU_DEV_REFCNT
10744 	free_percpu(dev->pcpu_refcnt);
10745 	dev->pcpu_refcnt = NULL;
10746 #endif
10747 	free_percpu(dev->core_stats);
10748 	dev->core_stats = NULL;
10749 	free_percpu(dev->xdp_bulkq);
10750 	dev->xdp_bulkq = NULL;
10751 
10752 	/*  Compatibility with error handling in drivers */
10753 	if (dev->reg_state == NETREG_UNINITIALIZED) {
10754 		netdev_freemem(dev);
10755 		return;
10756 	}
10757 
10758 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10759 	dev->reg_state = NETREG_RELEASED;
10760 
10761 	/* will free via device release */
10762 	put_device(&dev->dev);
10763 }
10764 EXPORT_SYMBOL(free_netdev);
10765 
10766 /**
10767  *	synchronize_net -  Synchronize with packet receive processing
10768  *
10769  *	Wait for packets currently being received to be done.
10770  *	Does not block later packets from starting.
10771  */
10772 void synchronize_net(void)
10773 {
10774 	might_sleep();
10775 	if (rtnl_is_locked())
10776 		synchronize_rcu_expedited();
10777 	else
10778 		synchronize_rcu();
10779 }
10780 EXPORT_SYMBOL(synchronize_net);
10781 
10782 /**
10783  *	unregister_netdevice_queue - remove device from the kernel
10784  *	@dev: device
10785  *	@head: list
10786  *
10787  *	This function shuts down a device interface and removes it
10788  *	from the kernel tables.
10789  *	If head not NULL, device is queued to be unregistered later.
10790  *
10791  *	Callers must hold the rtnl semaphore.  You may want
10792  *	unregister_netdev() instead of this.
10793  */
10794 
10795 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10796 {
10797 	ASSERT_RTNL();
10798 
10799 	if (head) {
10800 		list_move_tail(&dev->unreg_list, head);
10801 	} else {
10802 		LIST_HEAD(single);
10803 
10804 		list_add(&dev->unreg_list, &single);
10805 		unregister_netdevice_many(&single);
10806 	}
10807 }
10808 EXPORT_SYMBOL(unregister_netdevice_queue);
10809 
10810 void unregister_netdevice_many_notify(struct list_head *head,
10811 				      u32 portid, const struct nlmsghdr *nlh)
10812 {
10813 	struct net_device *dev, *tmp;
10814 	LIST_HEAD(close_head);
10815 
10816 	BUG_ON(dev_boot_phase);
10817 	ASSERT_RTNL();
10818 
10819 	if (list_empty(head))
10820 		return;
10821 
10822 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10823 		/* Some devices call without registering
10824 		 * for initialization unwind. Remove those
10825 		 * devices and proceed with the remaining.
10826 		 */
10827 		if (dev->reg_state == NETREG_UNINITIALIZED) {
10828 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10829 				 dev->name, dev);
10830 
10831 			WARN_ON(1);
10832 			list_del(&dev->unreg_list);
10833 			continue;
10834 		}
10835 		dev->dismantle = true;
10836 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
10837 	}
10838 
10839 	/* If device is running, close it first. */
10840 	list_for_each_entry(dev, head, unreg_list)
10841 		list_add_tail(&dev->close_list, &close_head);
10842 	dev_close_many(&close_head, true);
10843 
10844 	list_for_each_entry(dev, head, unreg_list) {
10845 		/* And unlink it from device chain. */
10846 		write_lock(&dev_base_lock);
10847 		unlist_netdevice(dev, false);
10848 		dev->reg_state = NETREG_UNREGISTERING;
10849 		write_unlock(&dev_base_lock);
10850 	}
10851 	flush_all_backlogs();
10852 
10853 	synchronize_net();
10854 
10855 	list_for_each_entry(dev, head, unreg_list) {
10856 		struct sk_buff *skb = NULL;
10857 
10858 		/* Shutdown queueing discipline. */
10859 		dev_shutdown(dev);
10860 
10861 		dev_xdp_uninstall(dev);
10862 		bpf_dev_bound_netdev_unregister(dev);
10863 
10864 		netdev_offload_xstats_disable_all(dev);
10865 
10866 		/* Notify protocols, that we are about to destroy
10867 		 * this device. They should clean all the things.
10868 		 */
10869 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10870 
10871 		if (!dev->rtnl_link_ops ||
10872 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10873 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10874 						     GFP_KERNEL, NULL, 0,
10875 						     portid, nlmsg_seq(nlh));
10876 
10877 		/*
10878 		 *	Flush the unicast and multicast chains
10879 		 */
10880 		dev_uc_flush(dev);
10881 		dev_mc_flush(dev);
10882 
10883 		netdev_name_node_alt_flush(dev);
10884 		netdev_name_node_free(dev->name_node);
10885 
10886 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10887 
10888 		if (dev->netdev_ops->ndo_uninit)
10889 			dev->netdev_ops->ndo_uninit(dev);
10890 
10891 		if (skb)
10892 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
10893 
10894 		/* Notifier chain MUST detach us all upper devices. */
10895 		WARN_ON(netdev_has_any_upper_dev(dev));
10896 		WARN_ON(netdev_has_any_lower_dev(dev));
10897 
10898 		/* Remove entries from kobject tree */
10899 		netdev_unregister_kobject(dev);
10900 #ifdef CONFIG_XPS
10901 		/* Remove XPS queueing entries */
10902 		netif_reset_xps_queues_gt(dev, 0);
10903 #endif
10904 	}
10905 
10906 	synchronize_net();
10907 
10908 	list_for_each_entry(dev, head, unreg_list) {
10909 		netdev_put(dev, &dev->dev_registered_tracker);
10910 		net_set_todo(dev);
10911 	}
10912 
10913 	list_del(head);
10914 }
10915 
10916 /**
10917  *	unregister_netdevice_many - unregister many devices
10918  *	@head: list of devices
10919  *
10920  *  Note: As most callers use a stack allocated list_head,
10921  *  we force a list_del() to make sure stack wont be corrupted later.
10922  */
10923 void unregister_netdevice_many(struct list_head *head)
10924 {
10925 	unregister_netdevice_many_notify(head, 0, NULL);
10926 }
10927 EXPORT_SYMBOL(unregister_netdevice_many);
10928 
10929 /**
10930  *	unregister_netdev - remove device from the kernel
10931  *	@dev: device
10932  *
10933  *	This function shuts down a device interface and removes it
10934  *	from the kernel tables.
10935  *
10936  *	This is just a wrapper for unregister_netdevice that takes
10937  *	the rtnl semaphore.  In general you want to use this and not
10938  *	unregister_netdevice.
10939  */
10940 void unregister_netdev(struct net_device *dev)
10941 {
10942 	rtnl_lock();
10943 	unregister_netdevice(dev);
10944 	rtnl_unlock();
10945 }
10946 EXPORT_SYMBOL(unregister_netdev);
10947 
10948 /**
10949  *	__dev_change_net_namespace - move device to different nethost namespace
10950  *	@dev: device
10951  *	@net: network namespace
10952  *	@pat: If not NULL name pattern to try if the current device name
10953  *	      is already taken in the destination network namespace.
10954  *	@new_ifindex: If not zero, specifies device index in the target
10955  *	              namespace.
10956  *
10957  *	This function shuts down a device interface and moves it
10958  *	to a new network namespace. On success 0 is returned, on
10959  *	a failure a netagive errno code is returned.
10960  *
10961  *	Callers must hold the rtnl semaphore.
10962  */
10963 
10964 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
10965 			       const char *pat, int new_ifindex)
10966 {
10967 	struct net *net_old = dev_net(dev);
10968 	int err, new_nsid;
10969 
10970 	ASSERT_RTNL();
10971 
10972 	/* Don't allow namespace local devices to be moved. */
10973 	err = -EINVAL;
10974 	if (dev->features & NETIF_F_NETNS_LOCAL)
10975 		goto out;
10976 
10977 	/* Ensure the device has been registrered */
10978 	if (dev->reg_state != NETREG_REGISTERED)
10979 		goto out;
10980 
10981 	/* Get out if there is nothing todo */
10982 	err = 0;
10983 	if (net_eq(net_old, net))
10984 		goto out;
10985 
10986 	/* Pick the destination device name, and ensure
10987 	 * we can use it in the destination network namespace.
10988 	 */
10989 	err = -EEXIST;
10990 	if (netdev_name_in_use(net, dev->name)) {
10991 		/* We get here if we can't use the current device name */
10992 		if (!pat)
10993 			goto out;
10994 		err = dev_get_valid_name(net, dev, pat);
10995 		if (err < 0)
10996 			goto out;
10997 	}
10998 
10999 	/* Check that new_ifindex isn't used yet. */
11000 	err = -EBUSY;
11001 	if (new_ifindex && __dev_get_by_index(net, new_ifindex))
11002 		goto out;
11003 
11004 	/*
11005 	 * And now a mini version of register_netdevice unregister_netdevice.
11006 	 */
11007 
11008 	/* If device is running close it first. */
11009 	dev_close(dev);
11010 
11011 	/* And unlink it from device chain */
11012 	unlist_netdevice(dev, true);
11013 
11014 	synchronize_net();
11015 
11016 	/* Shutdown queueing discipline. */
11017 	dev_shutdown(dev);
11018 
11019 	/* Notify protocols, that we are about to destroy
11020 	 * this device. They should clean all the things.
11021 	 *
11022 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
11023 	 * This is wanted because this way 8021q and macvlan know
11024 	 * the device is just moving and can keep their slaves up.
11025 	 */
11026 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11027 	rcu_barrier();
11028 
11029 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11030 	/* If there is an ifindex conflict assign a new one */
11031 	if (!new_ifindex) {
11032 		if (__dev_get_by_index(net, dev->ifindex))
11033 			new_ifindex = dev_new_index(net);
11034 		else
11035 			new_ifindex = dev->ifindex;
11036 	}
11037 
11038 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11039 			    new_ifindex);
11040 
11041 	/*
11042 	 *	Flush the unicast and multicast chains
11043 	 */
11044 	dev_uc_flush(dev);
11045 	dev_mc_flush(dev);
11046 
11047 	/* Send a netdev-removed uevent to the old namespace */
11048 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11049 	netdev_adjacent_del_links(dev);
11050 
11051 	/* Move per-net netdevice notifiers that are following the netdevice */
11052 	move_netdevice_notifiers_dev_net(dev, net);
11053 
11054 	/* Actually switch the network namespace */
11055 	dev_net_set(dev, net);
11056 	dev->ifindex = new_ifindex;
11057 
11058 	/* Send a netdev-add uevent to the new namespace */
11059 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11060 	netdev_adjacent_add_links(dev);
11061 
11062 	/* Fixup kobjects */
11063 	err = device_rename(&dev->dev, dev->name);
11064 	WARN_ON(err);
11065 
11066 	/* Adapt owner in case owning user namespace of target network
11067 	 * namespace is different from the original one.
11068 	 */
11069 	err = netdev_change_owner(dev, net_old, net);
11070 	WARN_ON(err);
11071 
11072 	/* Add the device back in the hashes */
11073 	list_netdevice(dev);
11074 
11075 	/* Notify protocols, that a new device appeared. */
11076 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11077 
11078 	/*
11079 	 *	Prevent userspace races by waiting until the network
11080 	 *	device is fully setup before sending notifications.
11081 	 */
11082 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11083 
11084 	synchronize_net();
11085 	err = 0;
11086 out:
11087 	return err;
11088 }
11089 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11090 
11091 static int dev_cpu_dead(unsigned int oldcpu)
11092 {
11093 	struct sk_buff **list_skb;
11094 	struct sk_buff *skb;
11095 	unsigned int cpu;
11096 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11097 
11098 	local_irq_disable();
11099 	cpu = smp_processor_id();
11100 	sd = &per_cpu(softnet_data, cpu);
11101 	oldsd = &per_cpu(softnet_data, oldcpu);
11102 
11103 	/* Find end of our completion_queue. */
11104 	list_skb = &sd->completion_queue;
11105 	while (*list_skb)
11106 		list_skb = &(*list_skb)->next;
11107 	/* Append completion queue from offline CPU. */
11108 	*list_skb = oldsd->completion_queue;
11109 	oldsd->completion_queue = NULL;
11110 
11111 	/* Append output queue from offline CPU. */
11112 	if (oldsd->output_queue) {
11113 		*sd->output_queue_tailp = oldsd->output_queue;
11114 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11115 		oldsd->output_queue = NULL;
11116 		oldsd->output_queue_tailp = &oldsd->output_queue;
11117 	}
11118 	/* Append NAPI poll list from offline CPU, with one exception :
11119 	 * process_backlog() must be called by cpu owning percpu backlog.
11120 	 * We properly handle process_queue & input_pkt_queue later.
11121 	 */
11122 	while (!list_empty(&oldsd->poll_list)) {
11123 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11124 							    struct napi_struct,
11125 							    poll_list);
11126 
11127 		list_del_init(&napi->poll_list);
11128 		if (napi->poll == process_backlog)
11129 			napi->state = 0;
11130 		else
11131 			____napi_schedule(sd, napi);
11132 	}
11133 
11134 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11135 	local_irq_enable();
11136 
11137 #ifdef CONFIG_RPS
11138 	remsd = oldsd->rps_ipi_list;
11139 	oldsd->rps_ipi_list = NULL;
11140 #endif
11141 	/* send out pending IPI's on offline CPU */
11142 	net_rps_send_ipi(remsd);
11143 
11144 	/* Process offline CPU's input_pkt_queue */
11145 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11146 		netif_rx(skb);
11147 		input_queue_head_incr(oldsd);
11148 	}
11149 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11150 		netif_rx(skb);
11151 		input_queue_head_incr(oldsd);
11152 	}
11153 
11154 	return 0;
11155 }
11156 
11157 /**
11158  *	netdev_increment_features - increment feature set by one
11159  *	@all: current feature set
11160  *	@one: new feature set
11161  *	@mask: mask feature set
11162  *
11163  *	Computes a new feature set after adding a device with feature set
11164  *	@one to the master device with current feature set @all.  Will not
11165  *	enable anything that is off in @mask. Returns the new feature set.
11166  */
11167 netdev_features_t netdev_increment_features(netdev_features_t all,
11168 	netdev_features_t one, netdev_features_t mask)
11169 {
11170 	if (mask & NETIF_F_HW_CSUM)
11171 		mask |= NETIF_F_CSUM_MASK;
11172 	mask |= NETIF_F_VLAN_CHALLENGED;
11173 
11174 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11175 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11176 
11177 	/* If one device supports hw checksumming, set for all. */
11178 	if (all & NETIF_F_HW_CSUM)
11179 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11180 
11181 	return all;
11182 }
11183 EXPORT_SYMBOL(netdev_increment_features);
11184 
11185 static struct hlist_head * __net_init netdev_create_hash(void)
11186 {
11187 	int i;
11188 	struct hlist_head *hash;
11189 
11190 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11191 	if (hash != NULL)
11192 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11193 			INIT_HLIST_HEAD(&hash[i]);
11194 
11195 	return hash;
11196 }
11197 
11198 /* Initialize per network namespace state */
11199 static int __net_init netdev_init(struct net *net)
11200 {
11201 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11202 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11203 
11204 	INIT_LIST_HEAD(&net->dev_base_head);
11205 
11206 	net->dev_name_head = netdev_create_hash();
11207 	if (net->dev_name_head == NULL)
11208 		goto err_name;
11209 
11210 	net->dev_index_head = netdev_create_hash();
11211 	if (net->dev_index_head == NULL)
11212 		goto err_idx;
11213 
11214 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11215 
11216 	return 0;
11217 
11218 err_idx:
11219 	kfree(net->dev_name_head);
11220 err_name:
11221 	return -ENOMEM;
11222 }
11223 
11224 /**
11225  *	netdev_drivername - network driver for the device
11226  *	@dev: network device
11227  *
11228  *	Determine network driver for device.
11229  */
11230 const char *netdev_drivername(const struct net_device *dev)
11231 {
11232 	const struct device_driver *driver;
11233 	const struct device *parent;
11234 	const char *empty = "";
11235 
11236 	parent = dev->dev.parent;
11237 	if (!parent)
11238 		return empty;
11239 
11240 	driver = parent->driver;
11241 	if (driver && driver->name)
11242 		return driver->name;
11243 	return empty;
11244 }
11245 
11246 static void __netdev_printk(const char *level, const struct net_device *dev,
11247 			    struct va_format *vaf)
11248 {
11249 	if (dev && dev->dev.parent) {
11250 		dev_printk_emit(level[1] - '0',
11251 				dev->dev.parent,
11252 				"%s %s %s%s: %pV",
11253 				dev_driver_string(dev->dev.parent),
11254 				dev_name(dev->dev.parent),
11255 				netdev_name(dev), netdev_reg_state(dev),
11256 				vaf);
11257 	} else if (dev) {
11258 		printk("%s%s%s: %pV",
11259 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11260 	} else {
11261 		printk("%s(NULL net_device): %pV", level, vaf);
11262 	}
11263 }
11264 
11265 void netdev_printk(const char *level, const struct net_device *dev,
11266 		   const char *format, ...)
11267 {
11268 	struct va_format vaf;
11269 	va_list args;
11270 
11271 	va_start(args, format);
11272 
11273 	vaf.fmt = format;
11274 	vaf.va = &args;
11275 
11276 	__netdev_printk(level, dev, &vaf);
11277 
11278 	va_end(args);
11279 }
11280 EXPORT_SYMBOL(netdev_printk);
11281 
11282 #define define_netdev_printk_level(func, level)			\
11283 void func(const struct net_device *dev, const char *fmt, ...)	\
11284 {								\
11285 	struct va_format vaf;					\
11286 	va_list args;						\
11287 								\
11288 	va_start(args, fmt);					\
11289 								\
11290 	vaf.fmt = fmt;						\
11291 	vaf.va = &args;						\
11292 								\
11293 	__netdev_printk(level, dev, &vaf);			\
11294 								\
11295 	va_end(args);						\
11296 }								\
11297 EXPORT_SYMBOL(func);
11298 
11299 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11300 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11301 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11302 define_netdev_printk_level(netdev_err, KERN_ERR);
11303 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11304 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11305 define_netdev_printk_level(netdev_info, KERN_INFO);
11306 
11307 static void __net_exit netdev_exit(struct net *net)
11308 {
11309 	kfree(net->dev_name_head);
11310 	kfree(net->dev_index_head);
11311 	if (net != &init_net)
11312 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11313 }
11314 
11315 static struct pernet_operations __net_initdata netdev_net_ops = {
11316 	.init = netdev_init,
11317 	.exit = netdev_exit,
11318 };
11319 
11320 static void __net_exit default_device_exit_net(struct net *net)
11321 {
11322 	struct net_device *dev, *aux;
11323 	/*
11324 	 * Push all migratable network devices back to the
11325 	 * initial network namespace
11326 	 */
11327 	ASSERT_RTNL();
11328 	for_each_netdev_safe(net, dev, aux) {
11329 		int err;
11330 		char fb_name[IFNAMSIZ];
11331 
11332 		/* Ignore unmoveable devices (i.e. loopback) */
11333 		if (dev->features & NETIF_F_NETNS_LOCAL)
11334 			continue;
11335 
11336 		/* Leave virtual devices for the generic cleanup */
11337 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11338 			continue;
11339 
11340 		/* Push remaining network devices to init_net */
11341 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11342 		if (netdev_name_in_use(&init_net, fb_name))
11343 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11344 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11345 		if (err) {
11346 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11347 				 __func__, dev->name, err);
11348 			BUG();
11349 		}
11350 	}
11351 }
11352 
11353 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11354 {
11355 	/* At exit all network devices most be removed from a network
11356 	 * namespace.  Do this in the reverse order of registration.
11357 	 * Do this across as many network namespaces as possible to
11358 	 * improve batching efficiency.
11359 	 */
11360 	struct net_device *dev;
11361 	struct net *net;
11362 	LIST_HEAD(dev_kill_list);
11363 
11364 	rtnl_lock();
11365 	list_for_each_entry(net, net_list, exit_list) {
11366 		default_device_exit_net(net);
11367 		cond_resched();
11368 	}
11369 
11370 	list_for_each_entry(net, net_list, exit_list) {
11371 		for_each_netdev_reverse(net, dev) {
11372 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11373 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11374 			else
11375 				unregister_netdevice_queue(dev, &dev_kill_list);
11376 		}
11377 	}
11378 	unregister_netdevice_many(&dev_kill_list);
11379 	rtnl_unlock();
11380 }
11381 
11382 static struct pernet_operations __net_initdata default_device_ops = {
11383 	.exit_batch = default_device_exit_batch,
11384 };
11385 
11386 /*
11387  *	Initialize the DEV module. At boot time this walks the device list and
11388  *	unhooks any devices that fail to initialise (normally hardware not
11389  *	present) and leaves us with a valid list of present and active devices.
11390  *
11391  */
11392 
11393 /*
11394  *       This is called single threaded during boot, so no need
11395  *       to take the rtnl semaphore.
11396  */
11397 static int __init net_dev_init(void)
11398 {
11399 	int i, rc = -ENOMEM;
11400 
11401 	BUG_ON(!dev_boot_phase);
11402 
11403 	if (dev_proc_init())
11404 		goto out;
11405 
11406 	if (netdev_kobject_init())
11407 		goto out;
11408 
11409 	INIT_LIST_HEAD(&ptype_all);
11410 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
11411 		INIT_LIST_HEAD(&ptype_base[i]);
11412 
11413 	if (register_pernet_subsys(&netdev_net_ops))
11414 		goto out;
11415 
11416 	/*
11417 	 *	Initialise the packet receive queues.
11418 	 */
11419 
11420 	for_each_possible_cpu(i) {
11421 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11422 		struct softnet_data *sd = &per_cpu(softnet_data, i);
11423 
11424 		INIT_WORK(flush, flush_backlog);
11425 
11426 		skb_queue_head_init(&sd->input_pkt_queue);
11427 		skb_queue_head_init(&sd->process_queue);
11428 #ifdef CONFIG_XFRM_OFFLOAD
11429 		skb_queue_head_init(&sd->xfrm_backlog);
11430 #endif
11431 		INIT_LIST_HEAD(&sd->poll_list);
11432 		sd->output_queue_tailp = &sd->output_queue;
11433 #ifdef CONFIG_RPS
11434 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11435 		sd->cpu = i;
11436 #endif
11437 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11438 		spin_lock_init(&sd->defer_lock);
11439 
11440 		init_gro_hash(&sd->backlog);
11441 		sd->backlog.poll = process_backlog;
11442 		sd->backlog.weight = weight_p;
11443 	}
11444 
11445 	dev_boot_phase = 0;
11446 
11447 	/* The loopback device is special if any other network devices
11448 	 * is present in a network namespace the loopback device must
11449 	 * be present. Since we now dynamically allocate and free the
11450 	 * loopback device ensure this invariant is maintained by
11451 	 * keeping the loopback device as the first device on the
11452 	 * list of network devices.  Ensuring the loopback devices
11453 	 * is the first device that appears and the last network device
11454 	 * that disappears.
11455 	 */
11456 	if (register_pernet_device(&loopback_net_ops))
11457 		goto out;
11458 
11459 	if (register_pernet_device(&default_device_ops))
11460 		goto out;
11461 
11462 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11463 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11464 
11465 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11466 				       NULL, dev_cpu_dead);
11467 	WARN_ON(rc < 0);
11468 	rc = 0;
11469 out:
11470 	return rc;
11471 }
11472 
11473 subsys_initcall(net_dev_init);
11474