xref: /openbmc/linux/net/core/dev.c (revision d2237d35748e7f448a9c2d9dc6a85ef637466e24)
1 /*
2  * 	NET3	Protocol independent device support routines.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *	Derived from the non IP parts of dev.c 1.0.19
10  * 		Authors:	Ross Biro
11  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
13  *
14  *	Additional Authors:
15  *		Florian la Roche <rzsfl@rz.uni-sb.de>
16  *		Alan Cox <gw4pts@gw4pts.ampr.org>
17  *		David Hinds <dahinds@users.sourceforge.net>
18  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
19  *		Adam Sulmicki <adam@cfar.umd.edu>
20  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
21  *
22  *	Changes:
23  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
24  *              			to 2 if register_netdev gets called
25  *              			before net_dev_init & also removed a
26  *              			few lines of code in the process.
27  *		Alan Cox	:	device private ioctl copies fields back.
28  *		Alan Cox	:	Transmit queue code does relevant
29  *					stunts to keep the queue safe.
30  *		Alan Cox	:	Fixed double lock.
31  *		Alan Cox	:	Fixed promisc NULL pointer trap
32  *		????????	:	Support the full private ioctl range
33  *		Alan Cox	:	Moved ioctl permission check into
34  *					drivers
35  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
36  *		Alan Cox	:	100 backlog just doesn't cut it when
37  *					you start doing multicast video 8)
38  *		Alan Cox	:	Rewrote net_bh and list manager.
39  *		Alan Cox	: 	Fix ETH_P_ALL echoback lengths.
40  *		Alan Cox	:	Took out transmit every packet pass
41  *					Saved a few bytes in the ioctl handler
42  *		Alan Cox	:	Network driver sets packet type before
43  *					calling netif_rx. Saves a function
44  *					call a packet.
45  *		Alan Cox	:	Hashed net_bh()
46  *		Richard Kooijman:	Timestamp fixes.
47  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
48  *		Alan Cox	:	Device lock protection.
49  *		Alan Cox	: 	Fixed nasty side effect of device close
50  *					changes.
51  *		Rudi Cilibrasi	:	Pass the right thing to
52  *					set_mac_address()
53  *		Dave Miller	:	32bit quantity for the device lock to
54  *					make it work out on a Sparc.
55  *		Bjorn Ekwall	:	Added KERNELD hack.
56  *		Alan Cox	:	Cleaned up the backlog initialise.
57  *		Craig Metz	:	SIOCGIFCONF fix if space for under
58  *					1 device.
59  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
60  *					is no device open function.
61  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
62  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
63  *		Cyrus Durgin	:	Cleaned for KMOD
64  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
65  *					A network device unload needs to purge
66  *					the backlog queue.
67  *	Paul Rusty Russell	:	SIOCSIFNAME
68  *              Pekka Riikonen  :	Netdev boot-time settings code
69  *              Andrew Morton   :       Make unregister_netdevice wait
70  *              			indefinitely on dev->refcnt
71  * 		J Hadi Salim	:	- Backlog queue sampling
72  *				        - netif_rx() feedback
73  */
74 
75 #include <asm/uaccess.h>
76 #include <asm/system.h>
77 #include <linux/bitops.h>
78 #include <linux/capability.h>
79 #include <linux/cpu.h>
80 #include <linux/types.h>
81 #include <linux/kernel.h>
82 #include <linux/hash.h>
83 #include <linux/slab.h>
84 #include <linux/sched.h>
85 #include <linux/mutex.h>
86 #include <linux/string.h>
87 #include <linux/mm.h>
88 #include <linux/socket.h>
89 #include <linux/sockios.h>
90 #include <linux/errno.h>
91 #include <linux/interrupt.h>
92 #include <linux/if_ether.h>
93 #include <linux/netdevice.h>
94 #include <linux/etherdevice.h>
95 #include <linux/ethtool.h>
96 #include <linux/notifier.h>
97 #include <linux/skbuff.h>
98 #include <net/net_namespace.h>
99 #include <net/sock.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <linux/stat.h>
104 #include <net/dst.h>
105 #include <net/pkt_sched.h>
106 #include <net/checksum.h>
107 #include <net/xfrm.h>
108 #include <linux/highmem.h>
109 #include <linux/init.h>
110 #include <linux/kmod.h>
111 #include <linux/module.h>
112 #include <linux/netpoll.h>
113 #include <linux/rcupdate.h>
114 #include <linux/delay.h>
115 #include <net/wext.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 <linux/ipv6.h>
127 #include <linux/in.h>
128 #include <linux/jhash.h>
129 #include <linux/random.h>
130 #include <trace/events/napi.h>
131 #include <trace/events/net.h>
132 #include <trace/events/skb.h>
133 #include <linux/pci.h>
134 #include <linux/inetdevice.h>
135 #include <linux/cpu_rmap.h>
136 
137 #include "net-sysfs.h"
138 
139 /* Instead of increasing this, you should create a hash table. */
140 #define MAX_GRO_SKBS 8
141 
142 /* This should be increased if a protocol with a bigger head is added. */
143 #define GRO_MAX_HEAD (MAX_HEADER + 128)
144 
145 /*
146  *	The list of packet types we will receive (as opposed to discard)
147  *	and the routines to invoke.
148  *
149  *	Why 16. Because with 16 the only overlap we get on a hash of the
150  *	low nibble of the protocol value is RARP/SNAP/X.25.
151  *
152  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
153  *             sure which should go first, but I bet it won't make much
154  *             difference if we are running VLANs.  The good news is that
155  *             this protocol won't be in the list unless compiled in, so
156  *             the average user (w/out VLANs) will not be adversely affected.
157  *             --BLG
158  *
159  *		0800	IP
160  *		8100    802.1Q VLAN
161  *		0001	802.3
162  *		0002	AX.25
163  *		0004	802.2
164  *		8035	RARP
165  *		0005	SNAP
166  *		0805	X.25
167  *		0806	ARP
168  *		8137	IPX
169  *		0009	Localtalk
170  *		86DD	IPv6
171  */
172 
173 #define PTYPE_HASH_SIZE	(16)
174 #define PTYPE_HASH_MASK	(PTYPE_HASH_SIZE - 1)
175 
176 static DEFINE_SPINLOCK(ptype_lock);
177 static struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
178 static struct list_head ptype_all __read_mostly;	/* Taps */
179 
180 /*
181  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
182  * semaphore.
183  *
184  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
185  *
186  * Writers must hold the rtnl semaphore while they loop through the
187  * dev_base_head list, and hold dev_base_lock for writing when they do the
188  * actual updates.  This allows pure readers to access the list even
189  * while a writer is preparing to update it.
190  *
191  * To put it another way, dev_base_lock is held for writing only to
192  * protect against pure readers; the rtnl semaphore provides the
193  * protection against other writers.
194  *
195  * See, for example usages, register_netdevice() and
196  * unregister_netdevice(), which must be called with the rtnl
197  * semaphore held.
198  */
199 DEFINE_RWLOCK(dev_base_lock);
200 EXPORT_SYMBOL(dev_base_lock);
201 
202 static inline void dev_base_seq_inc(struct net *net)
203 {
204 	while (++net->dev_base_seq == 0);
205 }
206 
207 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
208 {
209 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
210 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
211 }
212 
213 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
214 {
215 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
216 }
217 
218 static inline void rps_lock(struct softnet_data *sd)
219 {
220 #ifdef CONFIG_RPS
221 	spin_lock(&sd->input_pkt_queue.lock);
222 #endif
223 }
224 
225 static inline void rps_unlock(struct softnet_data *sd)
226 {
227 #ifdef CONFIG_RPS
228 	spin_unlock(&sd->input_pkt_queue.lock);
229 #endif
230 }
231 
232 /* Device list insertion */
233 static int list_netdevice(struct net_device *dev)
234 {
235 	struct net *net = dev_net(dev);
236 
237 	ASSERT_RTNL();
238 
239 	write_lock_bh(&dev_base_lock);
240 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
241 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
242 	hlist_add_head_rcu(&dev->index_hlist,
243 			   dev_index_hash(net, dev->ifindex));
244 	write_unlock_bh(&dev_base_lock);
245 
246 	dev_base_seq_inc(net);
247 
248 	return 0;
249 }
250 
251 /* Device list removal
252  * caller must respect a RCU grace period before freeing/reusing dev
253  */
254 static void unlist_netdevice(struct net_device *dev)
255 {
256 	ASSERT_RTNL();
257 
258 	/* Unlink dev from the device chain */
259 	write_lock_bh(&dev_base_lock);
260 	list_del_rcu(&dev->dev_list);
261 	hlist_del_rcu(&dev->name_hlist);
262 	hlist_del_rcu(&dev->index_hlist);
263 	write_unlock_bh(&dev_base_lock);
264 
265 	dev_base_seq_inc(dev_net(dev));
266 }
267 
268 /*
269  *	Our notifier list
270  */
271 
272 static RAW_NOTIFIER_HEAD(netdev_chain);
273 
274 /*
275  *	Device drivers call our routines to queue packets here. We empty the
276  *	queue in the local softnet handler.
277  */
278 
279 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
280 EXPORT_PER_CPU_SYMBOL(softnet_data);
281 
282 #ifdef CONFIG_LOCKDEP
283 /*
284  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
285  * according to dev->type
286  */
287 static const unsigned short netdev_lock_type[] =
288 	{ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
289 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
290 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
291 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
292 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
293 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
294 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
295 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
296 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
297 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
298 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
299 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
300 	 ARPHRD_FCFABRIC, ARPHRD_IEEE802_TR, ARPHRD_IEEE80211,
301 	 ARPHRD_IEEE80211_PRISM, ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET,
302 	 ARPHRD_PHONET_PIPE, ARPHRD_IEEE802154,
303 	 ARPHRD_VOID, ARPHRD_NONE};
304 
305 static const char *const netdev_lock_name[] =
306 	{"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
307 	 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
308 	 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
309 	 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
310 	 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
311 	 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
312 	 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
313 	 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
314 	 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
315 	 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
316 	 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
317 	 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
318 	 "_xmit_FCFABRIC", "_xmit_IEEE802_TR", "_xmit_IEEE80211",
319 	 "_xmit_IEEE80211_PRISM", "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET",
320 	 "_xmit_PHONET_PIPE", "_xmit_IEEE802154",
321 	 "_xmit_VOID", "_xmit_NONE"};
322 
323 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
324 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
325 
326 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
327 {
328 	int i;
329 
330 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
331 		if (netdev_lock_type[i] == dev_type)
332 			return i;
333 	/* the last key is used by default */
334 	return ARRAY_SIZE(netdev_lock_type) - 1;
335 }
336 
337 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
338 						 unsigned short dev_type)
339 {
340 	int i;
341 
342 	i = netdev_lock_pos(dev_type);
343 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
344 				   netdev_lock_name[i]);
345 }
346 
347 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
348 {
349 	int i;
350 
351 	i = netdev_lock_pos(dev->type);
352 	lockdep_set_class_and_name(&dev->addr_list_lock,
353 				   &netdev_addr_lock_key[i],
354 				   netdev_lock_name[i]);
355 }
356 #else
357 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
358 						 unsigned short dev_type)
359 {
360 }
361 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
362 {
363 }
364 #endif
365 
366 /*******************************************************************************
367 
368 		Protocol management and registration routines
369 
370 *******************************************************************************/
371 
372 /*
373  *	Add a protocol ID to the list. Now that the input handler is
374  *	smarter we can dispense with all the messy stuff that used to be
375  *	here.
376  *
377  *	BEWARE!!! Protocol handlers, mangling input packets,
378  *	MUST BE last in hash buckets and checking protocol handlers
379  *	MUST start from promiscuous ptype_all chain in net_bh.
380  *	It is true now, do not change it.
381  *	Explanation follows: if protocol handler, mangling packet, will
382  *	be the first on list, it is not able to sense, that packet
383  *	is cloned and should be copied-on-write, so that it will
384  *	change it and subsequent readers will get broken packet.
385  *							--ANK (980803)
386  */
387 
388 static inline struct list_head *ptype_head(const struct packet_type *pt)
389 {
390 	if (pt->type == htons(ETH_P_ALL))
391 		return &ptype_all;
392 	else
393 		return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
394 }
395 
396 /**
397  *	dev_add_pack - add packet handler
398  *	@pt: packet type declaration
399  *
400  *	Add a protocol handler to the networking stack. The passed &packet_type
401  *	is linked into kernel lists and may not be freed until it has been
402  *	removed from the kernel lists.
403  *
404  *	This call does not sleep therefore it can not
405  *	guarantee all CPU's that are in middle of receiving packets
406  *	will see the new packet type (until the next received packet).
407  */
408 
409 void dev_add_pack(struct packet_type *pt)
410 {
411 	struct list_head *head = ptype_head(pt);
412 
413 	spin_lock(&ptype_lock);
414 	list_add_rcu(&pt->list, head);
415 	spin_unlock(&ptype_lock);
416 }
417 EXPORT_SYMBOL(dev_add_pack);
418 
419 /**
420  *	__dev_remove_pack	 - remove packet handler
421  *	@pt: packet type declaration
422  *
423  *	Remove a protocol handler that was previously added to the kernel
424  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
425  *	from the kernel lists and can be freed or reused once this function
426  *	returns.
427  *
428  *      The packet type might still be in use by receivers
429  *	and must not be freed until after all the CPU's have gone
430  *	through a quiescent state.
431  */
432 void __dev_remove_pack(struct packet_type *pt)
433 {
434 	struct list_head *head = ptype_head(pt);
435 	struct packet_type *pt1;
436 
437 	spin_lock(&ptype_lock);
438 
439 	list_for_each_entry(pt1, head, list) {
440 		if (pt == pt1) {
441 			list_del_rcu(&pt->list);
442 			goto out;
443 		}
444 	}
445 
446 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
447 out:
448 	spin_unlock(&ptype_lock);
449 }
450 EXPORT_SYMBOL(__dev_remove_pack);
451 
452 /**
453  *	dev_remove_pack	 - remove packet handler
454  *	@pt: packet type declaration
455  *
456  *	Remove a protocol handler that was previously added to the kernel
457  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
458  *	from the kernel lists and can be freed or reused once this function
459  *	returns.
460  *
461  *	This call sleeps to guarantee that no CPU is looking at the packet
462  *	type after return.
463  */
464 void dev_remove_pack(struct packet_type *pt)
465 {
466 	__dev_remove_pack(pt);
467 
468 	synchronize_net();
469 }
470 EXPORT_SYMBOL(dev_remove_pack);
471 
472 /******************************************************************************
473 
474 		      Device Boot-time Settings Routines
475 
476 *******************************************************************************/
477 
478 /* Boot time configuration table */
479 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
480 
481 /**
482  *	netdev_boot_setup_add	- add new setup entry
483  *	@name: name of the device
484  *	@map: configured settings for the device
485  *
486  *	Adds new setup entry to the dev_boot_setup list.  The function
487  *	returns 0 on error and 1 on success.  This is a generic routine to
488  *	all netdevices.
489  */
490 static int netdev_boot_setup_add(char *name, struct ifmap *map)
491 {
492 	struct netdev_boot_setup *s;
493 	int i;
494 
495 	s = dev_boot_setup;
496 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
497 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
498 			memset(s[i].name, 0, sizeof(s[i].name));
499 			strlcpy(s[i].name, name, IFNAMSIZ);
500 			memcpy(&s[i].map, map, sizeof(s[i].map));
501 			break;
502 		}
503 	}
504 
505 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
506 }
507 
508 /**
509  *	netdev_boot_setup_check	- check boot time settings
510  *	@dev: the netdevice
511  *
512  * 	Check boot time settings for the device.
513  *	The found settings are set for the device to be used
514  *	later in the device probing.
515  *	Returns 0 if no settings found, 1 if they are.
516  */
517 int netdev_boot_setup_check(struct net_device *dev)
518 {
519 	struct netdev_boot_setup *s = dev_boot_setup;
520 	int i;
521 
522 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
523 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
524 		    !strcmp(dev->name, s[i].name)) {
525 			dev->irq 	= s[i].map.irq;
526 			dev->base_addr 	= s[i].map.base_addr;
527 			dev->mem_start 	= s[i].map.mem_start;
528 			dev->mem_end 	= s[i].map.mem_end;
529 			return 1;
530 		}
531 	}
532 	return 0;
533 }
534 EXPORT_SYMBOL(netdev_boot_setup_check);
535 
536 
537 /**
538  *	netdev_boot_base	- get address from boot time settings
539  *	@prefix: prefix for network device
540  *	@unit: id for network device
541  *
542  * 	Check boot time settings for the base address of device.
543  *	The found settings are set for the device to be used
544  *	later in the device probing.
545  *	Returns 0 if no settings found.
546  */
547 unsigned long netdev_boot_base(const char *prefix, int unit)
548 {
549 	const struct netdev_boot_setup *s = dev_boot_setup;
550 	char name[IFNAMSIZ];
551 	int i;
552 
553 	sprintf(name, "%s%d", prefix, unit);
554 
555 	/*
556 	 * If device already registered then return base of 1
557 	 * to indicate not to probe for this interface
558 	 */
559 	if (__dev_get_by_name(&init_net, name))
560 		return 1;
561 
562 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
563 		if (!strcmp(name, s[i].name))
564 			return s[i].map.base_addr;
565 	return 0;
566 }
567 
568 /*
569  * Saves at boot time configured settings for any netdevice.
570  */
571 int __init netdev_boot_setup(char *str)
572 {
573 	int ints[5];
574 	struct ifmap map;
575 
576 	str = get_options(str, ARRAY_SIZE(ints), ints);
577 	if (!str || !*str)
578 		return 0;
579 
580 	/* Save settings */
581 	memset(&map, 0, sizeof(map));
582 	if (ints[0] > 0)
583 		map.irq = ints[1];
584 	if (ints[0] > 1)
585 		map.base_addr = ints[2];
586 	if (ints[0] > 2)
587 		map.mem_start = ints[3];
588 	if (ints[0] > 3)
589 		map.mem_end = ints[4];
590 
591 	/* Add new entry to the list */
592 	return netdev_boot_setup_add(str, &map);
593 }
594 
595 __setup("netdev=", netdev_boot_setup);
596 
597 /*******************************************************************************
598 
599 			    Device Interface Subroutines
600 
601 *******************************************************************************/
602 
603 /**
604  *	__dev_get_by_name	- find a device by its name
605  *	@net: the applicable net namespace
606  *	@name: name to find
607  *
608  *	Find an interface by name. Must be called under RTNL semaphore
609  *	or @dev_base_lock. If the name is found a pointer to the device
610  *	is returned. If the name is not found then %NULL is returned. The
611  *	reference counters are not incremented so the caller must be
612  *	careful with locks.
613  */
614 
615 struct net_device *__dev_get_by_name(struct net *net, const char *name)
616 {
617 	struct hlist_node *p;
618 	struct net_device *dev;
619 	struct hlist_head *head = dev_name_hash(net, name);
620 
621 	hlist_for_each_entry(dev, p, head, name_hlist)
622 		if (!strncmp(dev->name, name, IFNAMSIZ))
623 			return dev;
624 
625 	return NULL;
626 }
627 EXPORT_SYMBOL(__dev_get_by_name);
628 
629 /**
630  *	dev_get_by_name_rcu	- find a device by its name
631  *	@net: the applicable net namespace
632  *	@name: name to find
633  *
634  *	Find an interface by name.
635  *	If the name is found a pointer to the device is returned.
636  * 	If the name is not found then %NULL is returned.
637  *	The reference counters are not incremented so the caller must be
638  *	careful with locks. The caller must hold RCU lock.
639  */
640 
641 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
642 {
643 	struct hlist_node *p;
644 	struct net_device *dev;
645 	struct hlist_head *head = dev_name_hash(net, name);
646 
647 	hlist_for_each_entry_rcu(dev, p, head, name_hlist)
648 		if (!strncmp(dev->name, name, IFNAMSIZ))
649 			return dev;
650 
651 	return NULL;
652 }
653 EXPORT_SYMBOL(dev_get_by_name_rcu);
654 
655 /**
656  *	dev_get_by_name		- find a device by its name
657  *	@net: the applicable net namespace
658  *	@name: name to find
659  *
660  *	Find an interface by name. This can be called from any
661  *	context and does its own locking. The returned handle has
662  *	the usage count incremented and the caller must use dev_put() to
663  *	release it when it is no longer needed. %NULL is returned if no
664  *	matching device is found.
665  */
666 
667 struct net_device *dev_get_by_name(struct net *net, const char *name)
668 {
669 	struct net_device *dev;
670 
671 	rcu_read_lock();
672 	dev = dev_get_by_name_rcu(net, name);
673 	if (dev)
674 		dev_hold(dev);
675 	rcu_read_unlock();
676 	return dev;
677 }
678 EXPORT_SYMBOL(dev_get_by_name);
679 
680 /**
681  *	__dev_get_by_index - find a device by its ifindex
682  *	@net: the applicable net namespace
683  *	@ifindex: index of device
684  *
685  *	Search for an interface by index. Returns %NULL if the device
686  *	is not found or a pointer to the device. The device has not
687  *	had its reference counter increased so the caller must be careful
688  *	about locking. The caller must hold either the RTNL semaphore
689  *	or @dev_base_lock.
690  */
691 
692 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
693 {
694 	struct hlist_node *p;
695 	struct net_device *dev;
696 	struct hlist_head *head = dev_index_hash(net, ifindex);
697 
698 	hlist_for_each_entry(dev, p, head, index_hlist)
699 		if (dev->ifindex == ifindex)
700 			return dev;
701 
702 	return NULL;
703 }
704 EXPORT_SYMBOL(__dev_get_by_index);
705 
706 /**
707  *	dev_get_by_index_rcu - find a device by its ifindex
708  *	@net: the applicable net namespace
709  *	@ifindex: index of device
710  *
711  *	Search for an interface by index. Returns %NULL if the device
712  *	is not found or a pointer to the device. The device has not
713  *	had its reference counter increased so the caller must be careful
714  *	about locking. The caller must hold RCU lock.
715  */
716 
717 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
718 {
719 	struct hlist_node *p;
720 	struct net_device *dev;
721 	struct hlist_head *head = dev_index_hash(net, ifindex);
722 
723 	hlist_for_each_entry_rcu(dev, p, head, index_hlist)
724 		if (dev->ifindex == ifindex)
725 			return dev;
726 
727 	return NULL;
728 }
729 EXPORT_SYMBOL(dev_get_by_index_rcu);
730 
731 
732 /**
733  *	dev_get_by_index - find a device by its ifindex
734  *	@net: the applicable net namespace
735  *	@ifindex: index of device
736  *
737  *	Search for an interface by index. Returns NULL if the device
738  *	is not found or a pointer to the device. The device returned has
739  *	had a reference added and the pointer is safe until the user calls
740  *	dev_put to indicate they have finished with it.
741  */
742 
743 struct net_device *dev_get_by_index(struct net *net, int ifindex)
744 {
745 	struct net_device *dev;
746 
747 	rcu_read_lock();
748 	dev = dev_get_by_index_rcu(net, ifindex);
749 	if (dev)
750 		dev_hold(dev);
751 	rcu_read_unlock();
752 	return dev;
753 }
754 EXPORT_SYMBOL(dev_get_by_index);
755 
756 /**
757  *	dev_getbyhwaddr_rcu - find a device by its hardware address
758  *	@net: the applicable net namespace
759  *	@type: media type of device
760  *	@ha: hardware address
761  *
762  *	Search for an interface by MAC address. Returns NULL if the device
763  *	is not found or a pointer to the device.
764  *	The caller must hold RCU or RTNL.
765  *	The returned device has not had its ref count increased
766  *	and the caller must therefore be careful about locking
767  *
768  */
769 
770 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
771 				       const char *ha)
772 {
773 	struct net_device *dev;
774 
775 	for_each_netdev_rcu(net, dev)
776 		if (dev->type == type &&
777 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
778 			return dev;
779 
780 	return NULL;
781 }
782 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
783 
784 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
785 {
786 	struct net_device *dev;
787 
788 	ASSERT_RTNL();
789 	for_each_netdev(net, dev)
790 		if (dev->type == type)
791 			return dev;
792 
793 	return NULL;
794 }
795 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
796 
797 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
798 {
799 	struct net_device *dev, *ret = NULL;
800 
801 	rcu_read_lock();
802 	for_each_netdev_rcu(net, dev)
803 		if (dev->type == type) {
804 			dev_hold(dev);
805 			ret = dev;
806 			break;
807 		}
808 	rcu_read_unlock();
809 	return ret;
810 }
811 EXPORT_SYMBOL(dev_getfirstbyhwtype);
812 
813 /**
814  *	dev_get_by_flags_rcu - find any device with given flags
815  *	@net: the applicable net namespace
816  *	@if_flags: IFF_* values
817  *	@mask: bitmask of bits in if_flags to check
818  *
819  *	Search for any interface with the given flags. Returns NULL if a device
820  *	is not found or a pointer to the device. Must be called inside
821  *	rcu_read_lock(), and result refcount is unchanged.
822  */
823 
824 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
825 				    unsigned short mask)
826 {
827 	struct net_device *dev, *ret;
828 
829 	ret = NULL;
830 	for_each_netdev_rcu(net, dev) {
831 		if (((dev->flags ^ if_flags) & mask) == 0) {
832 			ret = dev;
833 			break;
834 		}
835 	}
836 	return ret;
837 }
838 EXPORT_SYMBOL(dev_get_by_flags_rcu);
839 
840 /**
841  *	dev_valid_name - check if name is okay for network device
842  *	@name: name string
843  *
844  *	Network device names need to be valid file names to
845  *	to allow sysfs to work.  We also disallow any kind of
846  *	whitespace.
847  */
848 int dev_valid_name(const char *name)
849 {
850 	if (*name == '\0')
851 		return 0;
852 	if (strlen(name) >= IFNAMSIZ)
853 		return 0;
854 	if (!strcmp(name, ".") || !strcmp(name, ".."))
855 		return 0;
856 
857 	while (*name) {
858 		if (*name == '/' || isspace(*name))
859 			return 0;
860 		name++;
861 	}
862 	return 1;
863 }
864 EXPORT_SYMBOL(dev_valid_name);
865 
866 /**
867  *	__dev_alloc_name - allocate a name for a device
868  *	@net: network namespace to allocate the device name in
869  *	@name: name format string
870  *	@buf:  scratch buffer and result name string
871  *
872  *	Passed a format string - eg "lt%d" it will try and find a suitable
873  *	id. It scans list of devices to build up a free map, then chooses
874  *	the first empty slot. The caller must hold the dev_base or rtnl lock
875  *	while allocating the name and adding the device in order to avoid
876  *	duplicates.
877  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
878  *	Returns the number of the unit assigned or a negative errno code.
879  */
880 
881 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
882 {
883 	int i = 0;
884 	const char *p;
885 	const int max_netdevices = 8*PAGE_SIZE;
886 	unsigned long *inuse;
887 	struct net_device *d;
888 
889 	p = strnchr(name, IFNAMSIZ-1, '%');
890 	if (p) {
891 		/*
892 		 * Verify the string as this thing may have come from
893 		 * the user.  There must be either one "%d" and no other "%"
894 		 * characters.
895 		 */
896 		if (p[1] != 'd' || strchr(p + 2, '%'))
897 			return -EINVAL;
898 
899 		/* Use one page as a bit array of possible slots */
900 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
901 		if (!inuse)
902 			return -ENOMEM;
903 
904 		for_each_netdev(net, d) {
905 			if (!sscanf(d->name, name, &i))
906 				continue;
907 			if (i < 0 || i >= max_netdevices)
908 				continue;
909 
910 			/*  avoid cases where sscanf is not exact inverse of printf */
911 			snprintf(buf, IFNAMSIZ, name, i);
912 			if (!strncmp(buf, d->name, IFNAMSIZ))
913 				set_bit(i, inuse);
914 		}
915 
916 		i = find_first_zero_bit(inuse, max_netdevices);
917 		free_page((unsigned long) inuse);
918 	}
919 
920 	if (buf != name)
921 		snprintf(buf, IFNAMSIZ, name, i);
922 	if (!__dev_get_by_name(net, buf))
923 		return i;
924 
925 	/* It is possible to run out of possible slots
926 	 * when the name is long and there isn't enough space left
927 	 * for the digits, or if all bits are used.
928 	 */
929 	return -ENFILE;
930 }
931 
932 /**
933  *	dev_alloc_name - allocate a name for a device
934  *	@dev: device
935  *	@name: name format string
936  *
937  *	Passed a format string - eg "lt%d" it will try and find a suitable
938  *	id. It scans list of devices to build up a free map, then chooses
939  *	the first empty slot. The caller must hold the dev_base or rtnl lock
940  *	while allocating the name and adding the device in order to avoid
941  *	duplicates.
942  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
943  *	Returns the number of the unit assigned or a negative errno code.
944  */
945 
946 int dev_alloc_name(struct net_device *dev, const char *name)
947 {
948 	char buf[IFNAMSIZ];
949 	struct net *net;
950 	int ret;
951 
952 	BUG_ON(!dev_net(dev));
953 	net = dev_net(dev);
954 	ret = __dev_alloc_name(net, name, buf);
955 	if (ret >= 0)
956 		strlcpy(dev->name, buf, IFNAMSIZ);
957 	return ret;
958 }
959 EXPORT_SYMBOL(dev_alloc_name);
960 
961 static int dev_get_valid_name(struct net_device *dev, const char *name)
962 {
963 	struct net *net;
964 
965 	BUG_ON(!dev_net(dev));
966 	net = dev_net(dev);
967 
968 	if (!dev_valid_name(name))
969 		return -EINVAL;
970 
971 	if (strchr(name, '%'))
972 		return dev_alloc_name(dev, name);
973 	else if (__dev_get_by_name(net, name))
974 		return -EEXIST;
975 	else if (dev->name != name)
976 		strlcpy(dev->name, name, IFNAMSIZ);
977 
978 	return 0;
979 }
980 
981 /**
982  *	dev_change_name - change name of a device
983  *	@dev: device
984  *	@newname: name (or format string) must be at least IFNAMSIZ
985  *
986  *	Change name of a device, can pass format strings "eth%d".
987  *	for wildcarding.
988  */
989 int dev_change_name(struct net_device *dev, const char *newname)
990 {
991 	char oldname[IFNAMSIZ];
992 	int err = 0;
993 	int ret;
994 	struct net *net;
995 
996 	ASSERT_RTNL();
997 	BUG_ON(!dev_net(dev));
998 
999 	net = dev_net(dev);
1000 	if (dev->flags & IFF_UP)
1001 		return -EBUSY;
1002 
1003 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
1004 		return 0;
1005 
1006 	memcpy(oldname, dev->name, IFNAMSIZ);
1007 
1008 	err = dev_get_valid_name(dev, newname);
1009 	if (err < 0)
1010 		return err;
1011 
1012 rollback:
1013 	ret = device_rename(&dev->dev, dev->name);
1014 	if (ret) {
1015 		memcpy(dev->name, oldname, IFNAMSIZ);
1016 		return ret;
1017 	}
1018 
1019 	write_lock_bh(&dev_base_lock);
1020 	hlist_del_rcu(&dev->name_hlist);
1021 	write_unlock_bh(&dev_base_lock);
1022 
1023 	synchronize_rcu();
1024 
1025 	write_lock_bh(&dev_base_lock);
1026 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1027 	write_unlock_bh(&dev_base_lock);
1028 
1029 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1030 	ret = notifier_to_errno(ret);
1031 
1032 	if (ret) {
1033 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1034 		if (err >= 0) {
1035 			err = ret;
1036 			memcpy(dev->name, oldname, IFNAMSIZ);
1037 			goto rollback;
1038 		} else {
1039 			printk(KERN_ERR
1040 			       "%s: name change rollback failed: %d.\n",
1041 			       dev->name, ret);
1042 		}
1043 	}
1044 
1045 	return err;
1046 }
1047 
1048 /**
1049  *	dev_set_alias - change ifalias of a device
1050  *	@dev: device
1051  *	@alias: name up to IFALIASZ
1052  *	@len: limit of bytes to copy from info
1053  *
1054  *	Set ifalias for a device,
1055  */
1056 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1057 {
1058 	ASSERT_RTNL();
1059 
1060 	if (len >= IFALIASZ)
1061 		return -EINVAL;
1062 
1063 	if (!len) {
1064 		if (dev->ifalias) {
1065 			kfree(dev->ifalias);
1066 			dev->ifalias = NULL;
1067 		}
1068 		return 0;
1069 	}
1070 
1071 	dev->ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1072 	if (!dev->ifalias)
1073 		return -ENOMEM;
1074 
1075 	strlcpy(dev->ifalias, alias, len+1);
1076 	return len;
1077 }
1078 
1079 
1080 /**
1081  *	netdev_features_change - device changes features
1082  *	@dev: device to cause notification
1083  *
1084  *	Called to indicate a device has changed features.
1085  */
1086 void netdev_features_change(struct net_device *dev)
1087 {
1088 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1089 }
1090 EXPORT_SYMBOL(netdev_features_change);
1091 
1092 /**
1093  *	netdev_state_change - device changes state
1094  *	@dev: device to cause notification
1095  *
1096  *	Called to indicate a device has changed state. This function calls
1097  *	the notifier chains for netdev_chain and sends a NEWLINK message
1098  *	to the routing socket.
1099  */
1100 void netdev_state_change(struct net_device *dev)
1101 {
1102 	if (dev->flags & IFF_UP) {
1103 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
1104 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1105 	}
1106 }
1107 EXPORT_SYMBOL(netdev_state_change);
1108 
1109 int netdev_bonding_change(struct net_device *dev, unsigned long event)
1110 {
1111 	return call_netdevice_notifiers(event, dev);
1112 }
1113 EXPORT_SYMBOL(netdev_bonding_change);
1114 
1115 /**
1116  *	dev_load 	- load a network module
1117  *	@net: the applicable net namespace
1118  *	@name: name of interface
1119  *
1120  *	If a network interface is not present and the process has suitable
1121  *	privileges this function loads the module. If module loading is not
1122  *	available in this kernel then it becomes a nop.
1123  */
1124 
1125 void dev_load(struct net *net, const char *name)
1126 {
1127 	struct net_device *dev;
1128 	int no_module;
1129 
1130 	rcu_read_lock();
1131 	dev = dev_get_by_name_rcu(net, name);
1132 	rcu_read_unlock();
1133 
1134 	no_module = !dev;
1135 	if (no_module && capable(CAP_NET_ADMIN))
1136 		no_module = request_module("netdev-%s", name);
1137 	if (no_module && capable(CAP_SYS_MODULE)) {
1138 		if (!request_module("%s", name))
1139 			pr_err("Loading kernel module for a network device "
1140 "with CAP_SYS_MODULE (deprecated).  Use CAP_NET_ADMIN and alias netdev-%s "
1141 "instead\n", name);
1142 	}
1143 }
1144 EXPORT_SYMBOL(dev_load);
1145 
1146 static int __dev_open(struct net_device *dev)
1147 {
1148 	const struct net_device_ops *ops = dev->netdev_ops;
1149 	int ret;
1150 
1151 	ASSERT_RTNL();
1152 
1153 	if (!netif_device_present(dev))
1154 		return -ENODEV;
1155 
1156 	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1157 	ret = notifier_to_errno(ret);
1158 	if (ret)
1159 		return ret;
1160 
1161 	set_bit(__LINK_STATE_START, &dev->state);
1162 
1163 	if (ops->ndo_validate_addr)
1164 		ret = ops->ndo_validate_addr(dev);
1165 
1166 	if (!ret && ops->ndo_open)
1167 		ret = ops->ndo_open(dev);
1168 
1169 	if (ret)
1170 		clear_bit(__LINK_STATE_START, &dev->state);
1171 	else {
1172 		dev->flags |= IFF_UP;
1173 		net_dmaengine_get();
1174 		dev_set_rx_mode(dev);
1175 		dev_activate(dev);
1176 	}
1177 
1178 	return ret;
1179 }
1180 
1181 /**
1182  *	dev_open	- prepare an interface for use.
1183  *	@dev:	device to open
1184  *
1185  *	Takes a device from down to up state. The device's private open
1186  *	function is invoked and then the multicast lists are loaded. Finally
1187  *	the device is moved into the up state and a %NETDEV_UP message is
1188  *	sent to the netdev notifier chain.
1189  *
1190  *	Calling this function on an active interface is a nop. On a failure
1191  *	a negative errno code is returned.
1192  */
1193 int dev_open(struct net_device *dev)
1194 {
1195 	int ret;
1196 
1197 	if (dev->flags & IFF_UP)
1198 		return 0;
1199 
1200 	ret = __dev_open(dev);
1201 	if (ret < 0)
1202 		return ret;
1203 
1204 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1205 	call_netdevice_notifiers(NETDEV_UP, dev);
1206 
1207 	return ret;
1208 }
1209 EXPORT_SYMBOL(dev_open);
1210 
1211 static int __dev_close_many(struct list_head *head)
1212 {
1213 	struct net_device *dev;
1214 
1215 	ASSERT_RTNL();
1216 	might_sleep();
1217 
1218 	list_for_each_entry(dev, head, unreg_list) {
1219 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1220 
1221 		clear_bit(__LINK_STATE_START, &dev->state);
1222 
1223 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1224 		 * can be even on different cpu. So just clear netif_running().
1225 		 *
1226 		 * dev->stop() will invoke napi_disable() on all of it's
1227 		 * napi_struct instances on this device.
1228 		 */
1229 		smp_mb__after_clear_bit(); /* Commit netif_running(). */
1230 	}
1231 
1232 	dev_deactivate_many(head);
1233 
1234 	list_for_each_entry(dev, head, unreg_list) {
1235 		const struct net_device_ops *ops = dev->netdev_ops;
1236 
1237 		/*
1238 		 *	Call the device specific close. This cannot fail.
1239 		 *	Only if device is UP
1240 		 *
1241 		 *	We allow it to be called even after a DETACH hot-plug
1242 		 *	event.
1243 		 */
1244 		if (ops->ndo_stop)
1245 			ops->ndo_stop(dev);
1246 
1247 		dev->flags &= ~IFF_UP;
1248 		net_dmaengine_put();
1249 	}
1250 
1251 	return 0;
1252 }
1253 
1254 static int __dev_close(struct net_device *dev)
1255 {
1256 	int retval;
1257 	LIST_HEAD(single);
1258 
1259 	list_add(&dev->unreg_list, &single);
1260 	retval = __dev_close_many(&single);
1261 	list_del(&single);
1262 	return retval;
1263 }
1264 
1265 static int dev_close_many(struct list_head *head)
1266 {
1267 	struct net_device *dev, *tmp;
1268 	LIST_HEAD(tmp_list);
1269 
1270 	list_for_each_entry_safe(dev, tmp, head, unreg_list)
1271 		if (!(dev->flags & IFF_UP))
1272 			list_move(&dev->unreg_list, &tmp_list);
1273 
1274 	__dev_close_many(head);
1275 
1276 	list_for_each_entry(dev, head, unreg_list) {
1277 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1278 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1279 	}
1280 
1281 	/* rollback_registered_many needs the complete original list */
1282 	list_splice(&tmp_list, head);
1283 	return 0;
1284 }
1285 
1286 /**
1287  *	dev_close - shutdown an interface.
1288  *	@dev: device to shutdown
1289  *
1290  *	This function moves an active device into down state. A
1291  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1292  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1293  *	chain.
1294  */
1295 int dev_close(struct net_device *dev)
1296 {
1297 	if (dev->flags & IFF_UP) {
1298 		LIST_HEAD(single);
1299 
1300 		list_add(&dev->unreg_list, &single);
1301 		dev_close_many(&single);
1302 		list_del(&single);
1303 	}
1304 	return 0;
1305 }
1306 EXPORT_SYMBOL(dev_close);
1307 
1308 
1309 /**
1310  *	dev_disable_lro - disable Large Receive Offload on a device
1311  *	@dev: device
1312  *
1313  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1314  *	called under RTNL.  This is needed if received packets may be
1315  *	forwarded to another interface.
1316  */
1317 void dev_disable_lro(struct net_device *dev)
1318 {
1319 	u32 flags;
1320 
1321 	/*
1322 	 * If we're trying to disable lro on a vlan device
1323 	 * use the underlying physical device instead
1324 	 */
1325 	if (is_vlan_dev(dev))
1326 		dev = vlan_dev_real_dev(dev);
1327 
1328 	if (dev->ethtool_ops && dev->ethtool_ops->get_flags)
1329 		flags = dev->ethtool_ops->get_flags(dev);
1330 	else
1331 		flags = ethtool_op_get_flags(dev);
1332 
1333 	if (!(flags & ETH_FLAG_LRO))
1334 		return;
1335 
1336 	__ethtool_set_flags(dev, flags & ~ETH_FLAG_LRO);
1337 	if (unlikely(dev->features & NETIF_F_LRO))
1338 		netdev_WARN(dev, "failed to disable LRO!\n");
1339 }
1340 EXPORT_SYMBOL(dev_disable_lro);
1341 
1342 
1343 static int dev_boot_phase = 1;
1344 
1345 /**
1346  *	register_netdevice_notifier - register a network notifier block
1347  *	@nb: notifier
1348  *
1349  *	Register a notifier to be called when network device events occur.
1350  *	The notifier passed is linked into the kernel structures and must
1351  *	not be reused until it has been unregistered. A negative errno code
1352  *	is returned on a failure.
1353  *
1354  * 	When registered all registration and up events are replayed
1355  *	to the new notifier to allow device to have a race free
1356  *	view of the network device list.
1357  */
1358 
1359 int register_netdevice_notifier(struct notifier_block *nb)
1360 {
1361 	struct net_device *dev;
1362 	struct net_device *last;
1363 	struct net *net;
1364 	int err;
1365 
1366 	rtnl_lock();
1367 	err = raw_notifier_chain_register(&netdev_chain, nb);
1368 	if (err)
1369 		goto unlock;
1370 	if (dev_boot_phase)
1371 		goto unlock;
1372 	for_each_net(net) {
1373 		for_each_netdev(net, dev) {
1374 			err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1375 			err = notifier_to_errno(err);
1376 			if (err)
1377 				goto rollback;
1378 
1379 			if (!(dev->flags & IFF_UP))
1380 				continue;
1381 
1382 			nb->notifier_call(nb, NETDEV_UP, dev);
1383 		}
1384 	}
1385 
1386 unlock:
1387 	rtnl_unlock();
1388 	return err;
1389 
1390 rollback:
1391 	last = dev;
1392 	for_each_net(net) {
1393 		for_each_netdev(net, dev) {
1394 			if (dev == last)
1395 				break;
1396 
1397 			if (dev->flags & IFF_UP) {
1398 				nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1399 				nb->notifier_call(nb, NETDEV_DOWN, dev);
1400 			}
1401 			nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1402 			nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
1403 		}
1404 	}
1405 
1406 	raw_notifier_chain_unregister(&netdev_chain, nb);
1407 	goto unlock;
1408 }
1409 EXPORT_SYMBOL(register_netdevice_notifier);
1410 
1411 /**
1412  *	unregister_netdevice_notifier - unregister a network notifier block
1413  *	@nb: notifier
1414  *
1415  *	Unregister a notifier previously registered by
1416  *	register_netdevice_notifier(). The notifier is unlinked into the
1417  *	kernel structures and may then be reused. A negative errno code
1418  *	is returned on a failure.
1419  */
1420 
1421 int unregister_netdevice_notifier(struct notifier_block *nb)
1422 {
1423 	int err;
1424 
1425 	rtnl_lock();
1426 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1427 	rtnl_unlock();
1428 	return err;
1429 }
1430 EXPORT_SYMBOL(unregister_netdevice_notifier);
1431 
1432 /**
1433  *	call_netdevice_notifiers - call all network notifier blocks
1434  *      @val: value passed unmodified to notifier function
1435  *      @dev: net_device pointer passed unmodified to notifier function
1436  *
1437  *	Call all network notifier blocks.  Parameters and return value
1438  *	are as for raw_notifier_call_chain().
1439  */
1440 
1441 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1442 {
1443 	ASSERT_RTNL();
1444 	return raw_notifier_call_chain(&netdev_chain, val, dev);
1445 }
1446 EXPORT_SYMBOL(call_netdevice_notifiers);
1447 
1448 /* When > 0 there are consumers of rx skb time stamps */
1449 static atomic_t netstamp_needed = ATOMIC_INIT(0);
1450 
1451 void net_enable_timestamp(void)
1452 {
1453 	atomic_inc(&netstamp_needed);
1454 }
1455 EXPORT_SYMBOL(net_enable_timestamp);
1456 
1457 void net_disable_timestamp(void)
1458 {
1459 	atomic_dec(&netstamp_needed);
1460 }
1461 EXPORT_SYMBOL(net_disable_timestamp);
1462 
1463 static inline void net_timestamp_set(struct sk_buff *skb)
1464 {
1465 	if (atomic_read(&netstamp_needed))
1466 		__net_timestamp(skb);
1467 	else
1468 		skb->tstamp.tv64 = 0;
1469 }
1470 
1471 static inline void net_timestamp_check(struct sk_buff *skb)
1472 {
1473 	if (!skb->tstamp.tv64 && atomic_read(&netstamp_needed))
1474 		__net_timestamp(skb);
1475 }
1476 
1477 static inline bool is_skb_forwardable(struct net_device *dev,
1478 				      struct sk_buff *skb)
1479 {
1480 	unsigned int len;
1481 
1482 	if (!(dev->flags & IFF_UP))
1483 		return false;
1484 
1485 	len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1486 	if (skb->len <= len)
1487 		return true;
1488 
1489 	/* if TSO is enabled, we don't care about the length as the packet
1490 	 * could be forwarded without being segmented before
1491 	 */
1492 	if (skb_is_gso(skb))
1493 		return true;
1494 
1495 	return false;
1496 }
1497 
1498 /**
1499  * dev_forward_skb - loopback an skb to another netif
1500  *
1501  * @dev: destination network device
1502  * @skb: buffer to forward
1503  *
1504  * return values:
1505  *	NET_RX_SUCCESS	(no congestion)
1506  *	NET_RX_DROP     (packet was dropped, but freed)
1507  *
1508  * dev_forward_skb can be used for injecting an skb from the
1509  * start_xmit function of one device into the receive queue
1510  * of another device.
1511  *
1512  * The receiving device may be in another namespace, so
1513  * we have to clear all information in the skb that could
1514  * impact namespace isolation.
1515  */
1516 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1517 {
1518 	if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
1519 		if (skb_copy_ubufs(skb, GFP_ATOMIC)) {
1520 			atomic_long_inc(&dev->rx_dropped);
1521 			kfree_skb(skb);
1522 			return NET_RX_DROP;
1523 		}
1524 	}
1525 
1526 	skb_orphan(skb);
1527 	nf_reset(skb);
1528 
1529 	if (unlikely(!is_skb_forwardable(dev, skb))) {
1530 		atomic_long_inc(&dev->rx_dropped);
1531 		kfree_skb(skb);
1532 		return NET_RX_DROP;
1533 	}
1534 	skb_set_dev(skb, dev);
1535 	skb->tstamp.tv64 = 0;
1536 	skb->pkt_type = PACKET_HOST;
1537 	skb->protocol = eth_type_trans(skb, dev);
1538 	return netif_rx(skb);
1539 }
1540 EXPORT_SYMBOL_GPL(dev_forward_skb);
1541 
1542 static inline int deliver_skb(struct sk_buff *skb,
1543 			      struct packet_type *pt_prev,
1544 			      struct net_device *orig_dev)
1545 {
1546 	atomic_inc(&skb->users);
1547 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1548 }
1549 
1550 /*
1551  *	Support routine. Sends outgoing frames to any network
1552  *	taps currently in use.
1553  */
1554 
1555 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1556 {
1557 	struct packet_type *ptype;
1558 	struct sk_buff *skb2 = NULL;
1559 	struct packet_type *pt_prev = NULL;
1560 
1561 	rcu_read_lock();
1562 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1563 		/* Never send packets back to the socket
1564 		 * they originated from - MvS (miquels@drinkel.ow.org)
1565 		 */
1566 		if ((ptype->dev == dev || !ptype->dev) &&
1567 		    (ptype->af_packet_priv == NULL ||
1568 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1569 			if (pt_prev) {
1570 				deliver_skb(skb2, pt_prev, skb->dev);
1571 				pt_prev = ptype;
1572 				continue;
1573 			}
1574 
1575 			skb2 = skb_clone(skb, GFP_ATOMIC);
1576 			if (!skb2)
1577 				break;
1578 
1579 			net_timestamp_set(skb2);
1580 
1581 			/* skb->nh should be correctly
1582 			   set by sender, so that the second statement is
1583 			   just protection against buggy protocols.
1584 			 */
1585 			skb_reset_mac_header(skb2);
1586 
1587 			if (skb_network_header(skb2) < skb2->data ||
1588 			    skb2->network_header > skb2->tail) {
1589 				if (net_ratelimit())
1590 					printk(KERN_CRIT "protocol %04x is "
1591 					       "buggy, dev %s\n",
1592 					       ntohs(skb2->protocol),
1593 					       dev->name);
1594 				skb_reset_network_header(skb2);
1595 			}
1596 
1597 			skb2->transport_header = skb2->network_header;
1598 			skb2->pkt_type = PACKET_OUTGOING;
1599 			pt_prev = ptype;
1600 		}
1601 	}
1602 	if (pt_prev)
1603 		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
1604 	rcu_read_unlock();
1605 }
1606 
1607 /* netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1608  * @dev: Network device
1609  * @txq: number of queues available
1610  *
1611  * If real_num_tx_queues is changed the tc mappings may no longer be
1612  * valid. To resolve this verify the tc mapping remains valid and if
1613  * not NULL the mapping. With no priorities mapping to this
1614  * offset/count pair it will no longer be used. In the worst case TC0
1615  * is invalid nothing can be done so disable priority mappings. If is
1616  * expected that drivers will fix this mapping if they can before
1617  * calling netif_set_real_num_tx_queues.
1618  */
1619 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1620 {
1621 	int i;
1622 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
1623 
1624 	/* If TC0 is invalidated disable TC mapping */
1625 	if (tc->offset + tc->count > txq) {
1626 		pr_warning("Number of in use tx queues changed "
1627 			   "invalidating tc mappings. Priority "
1628 			   "traffic classification disabled!\n");
1629 		dev->num_tc = 0;
1630 		return;
1631 	}
1632 
1633 	/* Invalidated prio to tc mappings set to TC0 */
1634 	for (i = 1; i < TC_BITMASK + 1; i++) {
1635 		int q = netdev_get_prio_tc_map(dev, i);
1636 
1637 		tc = &dev->tc_to_txq[q];
1638 		if (tc->offset + tc->count > txq) {
1639 			pr_warning("Number of in use tx queues "
1640 				   "changed. Priority %i to tc "
1641 				   "mapping %i is no longer valid "
1642 				   "setting map to 0\n",
1643 				   i, q);
1644 			netdev_set_prio_tc_map(dev, i, 0);
1645 		}
1646 	}
1647 }
1648 
1649 /*
1650  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
1651  * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
1652  */
1653 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
1654 {
1655 	int rc;
1656 
1657 	if (txq < 1 || txq > dev->num_tx_queues)
1658 		return -EINVAL;
1659 
1660 	if (dev->reg_state == NETREG_REGISTERED ||
1661 	    dev->reg_state == NETREG_UNREGISTERING) {
1662 		ASSERT_RTNL();
1663 
1664 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
1665 						  txq);
1666 		if (rc)
1667 			return rc;
1668 
1669 		if (dev->num_tc)
1670 			netif_setup_tc(dev, txq);
1671 
1672 		if (txq < dev->real_num_tx_queues)
1673 			qdisc_reset_all_tx_gt(dev, txq);
1674 	}
1675 
1676 	dev->real_num_tx_queues = txq;
1677 	return 0;
1678 }
1679 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
1680 
1681 #ifdef CONFIG_RPS
1682 /**
1683  *	netif_set_real_num_rx_queues - set actual number of RX queues used
1684  *	@dev: Network device
1685  *	@rxq: Actual number of RX queues
1686  *
1687  *	This must be called either with the rtnl_lock held or before
1688  *	registration of the net device.  Returns 0 on success, or a
1689  *	negative error code.  If called before registration, it always
1690  *	succeeds.
1691  */
1692 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
1693 {
1694 	int rc;
1695 
1696 	if (rxq < 1 || rxq > dev->num_rx_queues)
1697 		return -EINVAL;
1698 
1699 	if (dev->reg_state == NETREG_REGISTERED) {
1700 		ASSERT_RTNL();
1701 
1702 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
1703 						  rxq);
1704 		if (rc)
1705 			return rc;
1706 	}
1707 
1708 	dev->real_num_rx_queues = rxq;
1709 	return 0;
1710 }
1711 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
1712 #endif
1713 
1714 static inline void __netif_reschedule(struct Qdisc *q)
1715 {
1716 	struct softnet_data *sd;
1717 	unsigned long flags;
1718 
1719 	local_irq_save(flags);
1720 	sd = &__get_cpu_var(softnet_data);
1721 	q->next_sched = NULL;
1722 	*sd->output_queue_tailp = q;
1723 	sd->output_queue_tailp = &q->next_sched;
1724 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
1725 	local_irq_restore(flags);
1726 }
1727 
1728 void __netif_schedule(struct Qdisc *q)
1729 {
1730 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
1731 		__netif_reschedule(q);
1732 }
1733 EXPORT_SYMBOL(__netif_schedule);
1734 
1735 void dev_kfree_skb_irq(struct sk_buff *skb)
1736 {
1737 	if (atomic_dec_and_test(&skb->users)) {
1738 		struct softnet_data *sd;
1739 		unsigned long flags;
1740 
1741 		local_irq_save(flags);
1742 		sd = &__get_cpu_var(softnet_data);
1743 		skb->next = sd->completion_queue;
1744 		sd->completion_queue = skb;
1745 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
1746 		local_irq_restore(flags);
1747 	}
1748 }
1749 EXPORT_SYMBOL(dev_kfree_skb_irq);
1750 
1751 void dev_kfree_skb_any(struct sk_buff *skb)
1752 {
1753 	if (in_irq() || irqs_disabled())
1754 		dev_kfree_skb_irq(skb);
1755 	else
1756 		dev_kfree_skb(skb);
1757 }
1758 EXPORT_SYMBOL(dev_kfree_skb_any);
1759 
1760 
1761 /**
1762  * netif_device_detach - mark device as removed
1763  * @dev: network device
1764  *
1765  * Mark device as removed from system and therefore no longer available.
1766  */
1767 void netif_device_detach(struct net_device *dev)
1768 {
1769 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
1770 	    netif_running(dev)) {
1771 		netif_tx_stop_all_queues(dev);
1772 	}
1773 }
1774 EXPORT_SYMBOL(netif_device_detach);
1775 
1776 /**
1777  * netif_device_attach - mark device as attached
1778  * @dev: network device
1779  *
1780  * Mark device as attached from system and restart if needed.
1781  */
1782 void netif_device_attach(struct net_device *dev)
1783 {
1784 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
1785 	    netif_running(dev)) {
1786 		netif_tx_wake_all_queues(dev);
1787 		__netdev_watchdog_up(dev);
1788 	}
1789 }
1790 EXPORT_SYMBOL(netif_device_attach);
1791 
1792 /**
1793  * skb_dev_set -- assign a new device to a buffer
1794  * @skb: buffer for the new device
1795  * @dev: network device
1796  *
1797  * If an skb is owned by a device already, we have to reset
1798  * all data private to the namespace a device belongs to
1799  * before assigning it a new device.
1800  */
1801 #ifdef CONFIG_NET_NS
1802 void skb_set_dev(struct sk_buff *skb, struct net_device *dev)
1803 {
1804 	skb_dst_drop(skb);
1805 	if (skb->dev && !net_eq(dev_net(skb->dev), dev_net(dev))) {
1806 		secpath_reset(skb);
1807 		nf_reset(skb);
1808 		skb_init_secmark(skb);
1809 		skb->mark = 0;
1810 		skb->priority = 0;
1811 		skb->nf_trace = 0;
1812 		skb->ipvs_property = 0;
1813 #ifdef CONFIG_NET_SCHED
1814 		skb->tc_index = 0;
1815 #endif
1816 	}
1817 	skb->dev = dev;
1818 }
1819 EXPORT_SYMBOL(skb_set_dev);
1820 #endif /* CONFIG_NET_NS */
1821 
1822 /*
1823  * Invalidate hardware checksum when packet is to be mangled, and
1824  * complete checksum manually on outgoing path.
1825  */
1826 int skb_checksum_help(struct sk_buff *skb)
1827 {
1828 	__wsum csum;
1829 	int ret = 0, offset;
1830 
1831 	if (skb->ip_summed == CHECKSUM_COMPLETE)
1832 		goto out_set_summed;
1833 
1834 	if (unlikely(skb_shinfo(skb)->gso_size)) {
1835 		/* Let GSO fix up the checksum. */
1836 		goto out_set_summed;
1837 	}
1838 
1839 	offset = skb_checksum_start_offset(skb);
1840 	BUG_ON(offset >= skb_headlen(skb));
1841 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
1842 
1843 	offset += skb->csum_offset;
1844 	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
1845 
1846 	if (skb_cloned(skb) &&
1847 	    !skb_clone_writable(skb, offset + sizeof(__sum16))) {
1848 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1849 		if (ret)
1850 			goto out;
1851 	}
1852 
1853 	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
1854 out_set_summed:
1855 	skb->ip_summed = CHECKSUM_NONE;
1856 out:
1857 	return ret;
1858 }
1859 EXPORT_SYMBOL(skb_checksum_help);
1860 
1861 /**
1862  *	skb_gso_segment - Perform segmentation on skb.
1863  *	@skb: buffer to segment
1864  *	@features: features for the output path (see dev->features)
1865  *
1866  *	This function segments the given skb and returns a list of segments.
1867  *
1868  *	It may return NULL if the skb requires no segmentation.  This is
1869  *	only possible when GSO is used for verifying header integrity.
1870  */
1871 struct sk_buff *skb_gso_segment(struct sk_buff *skb, u32 features)
1872 {
1873 	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
1874 	struct packet_type *ptype;
1875 	__be16 type = skb->protocol;
1876 	int vlan_depth = ETH_HLEN;
1877 	int err;
1878 
1879 	while (type == htons(ETH_P_8021Q)) {
1880 		struct vlan_hdr *vh;
1881 
1882 		if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
1883 			return ERR_PTR(-EINVAL);
1884 
1885 		vh = (struct vlan_hdr *)(skb->data + vlan_depth);
1886 		type = vh->h_vlan_encapsulated_proto;
1887 		vlan_depth += VLAN_HLEN;
1888 	}
1889 
1890 	skb_reset_mac_header(skb);
1891 	skb->mac_len = skb->network_header - skb->mac_header;
1892 	__skb_pull(skb, skb->mac_len);
1893 
1894 	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1895 		struct net_device *dev = skb->dev;
1896 		struct ethtool_drvinfo info = {};
1897 
1898 		if (dev && dev->ethtool_ops && dev->ethtool_ops->get_drvinfo)
1899 			dev->ethtool_ops->get_drvinfo(dev, &info);
1900 
1901 		WARN(1, "%s: caps=(0x%lx, 0x%lx) len=%d data_len=%d ip_summed=%d\n",
1902 		     info.driver, dev ? dev->features : 0L,
1903 		     skb->sk ? skb->sk->sk_route_caps : 0L,
1904 		     skb->len, skb->data_len, skb->ip_summed);
1905 
1906 		if (skb_header_cloned(skb) &&
1907 		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
1908 			return ERR_PTR(err);
1909 	}
1910 
1911 	rcu_read_lock();
1912 	list_for_each_entry_rcu(ptype,
1913 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
1914 		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
1915 			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1916 				err = ptype->gso_send_check(skb);
1917 				segs = ERR_PTR(err);
1918 				if (err || skb_gso_ok(skb, features))
1919 					break;
1920 				__skb_push(skb, (skb->data -
1921 						 skb_network_header(skb)));
1922 			}
1923 			segs = ptype->gso_segment(skb, features);
1924 			break;
1925 		}
1926 	}
1927 	rcu_read_unlock();
1928 
1929 	__skb_push(skb, skb->data - skb_mac_header(skb));
1930 
1931 	return segs;
1932 }
1933 EXPORT_SYMBOL(skb_gso_segment);
1934 
1935 /* Take action when hardware reception checksum errors are detected. */
1936 #ifdef CONFIG_BUG
1937 void netdev_rx_csum_fault(struct net_device *dev)
1938 {
1939 	if (net_ratelimit()) {
1940 		printk(KERN_ERR "%s: hw csum failure.\n",
1941 			dev ? dev->name : "<unknown>");
1942 		dump_stack();
1943 	}
1944 }
1945 EXPORT_SYMBOL(netdev_rx_csum_fault);
1946 #endif
1947 
1948 /* Actually, we should eliminate this check as soon as we know, that:
1949  * 1. IOMMU is present and allows to map all the memory.
1950  * 2. No high memory really exists on this machine.
1951  */
1952 
1953 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1954 {
1955 #ifdef CONFIG_HIGHMEM
1956 	int i;
1957 	if (!(dev->features & NETIF_F_HIGHDMA)) {
1958 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1959 			if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1960 				return 1;
1961 	}
1962 
1963 	if (PCI_DMA_BUS_IS_PHYS) {
1964 		struct device *pdev = dev->dev.parent;
1965 
1966 		if (!pdev)
1967 			return 0;
1968 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1969 			dma_addr_t addr = page_to_phys(skb_shinfo(skb)->frags[i].page);
1970 			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
1971 				return 1;
1972 		}
1973 	}
1974 #endif
1975 	return 0;
1976 }
1977 
1978 struct dev_gso_cb {
1979 	void (*destructor)(struct sk_buff *skb);
1980 };
1981 
1982 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
1983 
1984 static void dev_gso_skb_destructor(struct sk_buff *skb)
1985 {
1986 	struct dev_gso_cb *cb;
1987 
1988 	do {
1989 		struct sk_buff *nskb = skb->next;
1990 
1991 		skb->next = nskb->next;
1992 		nskb->next = NULL;
1993 		kfree_skb(nskb);
1994 	} while (skb->next);
1995 
1996 	cb = DEV_GSO_CB(skb);
1997 	if (cb->destructor)
1998 		cb->destructor(skb);
1999 }
2000 
2001 /**
2002  *	dev_gso_segment - Perform emulated hardware segmentation on skb.
2003  *	@skb: buffer to segment
2004  *	@features: device features as applicable to this skb
2005  *
2006  *	This function segments the given skb and stores the list of segments
2007  *	in skb->next.
2008  */
2009 static int dev_gso_segment(struct sk_buff *skb, int features)
2010 {
2011 	struct sk_buff *segs;
2012 
2013 	segs = skb_gso_segment(skb, features);
2014 
2015 	/* Verifying header integrity only. */
2016 	if (!segs)
2017 		return 0;
2018 
2019 	if (IS_ERR(segs))
2020 		return PTR_ERR(segs);
2021 
2022 	skb->next = segs;
2023 	DEV_GSO_CB(skb)->destructor = skb->destructor;
2024 	skb->destructor = dev_gso_skb_destructor;
2025 
2026 	return 0;
2027 }
2028 
2029 /*
2030  * Try to orphan skb early, right before transmission by the device.
2031  * We cannot orphan skb if tx timestamp is requested or the sk-reference
2032  * is needed on driver level for other reasons, e.g. see net/can/raw.c
2033  */
2034 static inline void skb_orphan_try(struct sk_buff *skb)
2035 {
2036 	struct sock *sk = skb->sk;
2037 
2038 	if (sk && !skb_shinfo(skb)->tx_flags) {
2039 		/* skb_tx_hash() wont be able to get sk.
2040 		 * We copy sk_hash into skb->rxhash
2041 		 */
2042 		if (!skb->rxhash)
2043 			skb->rxhash = sk->sk_hash;
2044 		skb_orphan(skb);
2045 	}
2046 }
2047 
2048 static bool can_checksum_protocol(unsigned long features, __be16 protocol)
2049 {
2050 	return ((features & NETIF_F_GEN_CSUM) ||
2051 		((features & NETIF_F_V4_CSUM) &&
2052 		 protocol == htons(ETH_P_IP)) ||
2053 		((features & NETIF_F_V6_CSUM) &&
2054 		 protocol == htons(ETH_P_IPV6)) ||
2055 		((features & NETIF_F_FCOE_CRC) &&
2056 		 protocol == htons(ETH_P_FCOE)));
2057 }
2058 
2059 static u32 harmonize_features(struct sk_buff *skb, __be16 protocol, u32 features)
2060 {
2061 	if (!can_checksum_protocol(features, protocol)) {
2062 		features &= ~NETIF_F_ALL_CSUM;
2063 		features &= ~NETIF_F_SG;
2064 	} else if (illegal_highdma(skb->dev, skb)) {
2065 		features &= ~NETIF_F_SG;
2066 	}
2067 
2068 	return features;
2069 }
2070 
2071 u32 netif_skb_features(struct sk_buff *skb)
2072 {
2073 	__be16 protocol = skb->protocol;
2074 	u32 features = skb->dev->features;
2075 
2076 	if (protocol == htons(ETH_P_8021Q)) {
2077 		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
2078 		protocol = veh->h_vlan_encapsulated_proto;
2079 	} else if (!vlan_tx_tag_present(skb)) {
2080 		return harmonize_features(skb, protocol, features);
2081 	}
2082 
2083 	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_TX);
2084 
2085 	if (protocol != htons(ETH_P_8021Q)) {
2086 		return harmonize_features(skb, protocol, features);
2087 	} else {
2088 		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
2089 				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
2090 		return harmonize_features(skb, protocol, features);
2091 	}
2092 }
2093 EXPORT_SYMBOL(netif_skb_features);
2094 
2095 /*
2096  * Returns true if either:
2097  *	1. skb has frag_list and the device doesn't support FRAGLIST, or
2098  *	2. skb is fragmented and the device does not support SG, or if
2099  *	   at least one of fragments is in highmem and device does not
2100  *	   support DMA from it.
2101  */
2102 static inline int skb_needs_linearize(struct sk_buff *skb,
2103 				      int features)
2104 {
2105 	return skb_is_nonlinear(skb) &&
2106 			((skb_has_frag_list(skb) &&
2107 				!(features & NETIF_F_FRAGLIST)) ||
2108 			(skb_shinfo(skb)->nr_frags &&
2109 				!(features & NETIF_F_SG)));
2110 }
2111 
2112 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2113 			struct netdev_queue *txq)
2114 {
2115 	const struct net_device_ops *ops = dev->netdev_ops;
2116 	int rc = NETDEV_TX_OK;
2117 	unsigned int skb_len;
2118 
2119 	if (likely(!skb->next)) {
2120 		u32 features;
2121 
2122 		/*
2123 		 * If device doesn't need skb->dst, release it right now while
2124 		 * its hot in this cpu cache
2125 		 */
2126 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2127 			skb_dst_drop(skb);
2128 
2129 		if (!list_empty(&ptype_all))
2130 			dev_queue_xmit_nit(skb, dev);
2131 
2132 		skb_orphan_try(skb);
2133 
2134 		features = netif_skb_features(skb);
2135 
2136 		if (vlan_tx_tag_present(skb) &&
2137 		    !(features & NETIF_F_HW_VLAN_TX)) {
2138 			skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
2139 			if (unlikely(!skb))
2140 				goto out;
2141 
2142 			skb->vlan_tci = 0;
2143 		}
2144 
2145 		if (netif_needs_gso(skb, features)) {
2146 			if (unlikely(dev_gso_segment(skb, features)))
2147 				goto out_kfree_skb;
2148 			if (skb->next)
2149 				goto gso;
2150 		} else {
2151 			if (skb_needs_linearize(skb, features) &&
2152 			    __skb_linearize(skb))
2153 				goto out_kfree_skb;
2154 
2155 			/* If packet is not checksummed and device does not
2156 			 * support checksumming for this protocol, complete
2157 			 * checksumming here.
2158 			 */
2159 			if (skb->ip_summed == CHECKSUM_PARTIAL) {
2160 				skb_set_transport_header(skb,
2161 					skb_checksum_start_offset(skb));
2162 				if (!(features & NETIF_F_ALL_CSUM) &&
2163 				     skb_checksum_help(skb))
2164 					goto out_kfree_skb;
2165 			}
2166 		}
2167 
2168 		skb_len = skb->len;
2169 		rc = ops->ndo_start_xmit(skb, dev);
2170 		trace_net_dev_xmit(skb, rc, dev, skb_len);
2171 		if (rc == NETDEV_TX_OK)
2172 			txq_trans_update(txq);
2173 		return rc;
2174 	}
2175 
2176 gso:
2177 	do {
2178 		struct sk_buff *nskb = skb->next;
2179 
2180 		skb->next = nskb->next;
2181 		nskb->next = NULL;
2182 
2183 		/*
2184 		 * If device doesn't need nskb->dst, release it right now while
2185 		 * its hot in this cpu cache
2186 		 */
2187 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2188 			skb_dst_drop(nskb);
2189 
2190 		skb_len = nskb->len;
2191 		rc = ops->ndo_start_xmit(nskb, dev);
2192 		trace_net_dev_xmit(nskb, rc, dev, skb_len);
2193 		if (unlikely(rc != NETDEV_TX_OK)) {
2194 			if (rc & ~NETDEV_TX_MASK)
2195 				goto out_kfree_gso_skb;
2196 			nskb->next = skb->next;
2197 			skb->next = nskb;
2198 			return rc;
2199 		}
2200 		txq_trans_update(txq);
2201 		if (unlikely(netif_tx_queue_stopped(txq) && skb->next))
2202 			return NETDEV_TX_BUSY;
2203 	} while (skb->next);
2204 
2205 out_kfree_gso_skb:
2206 	if (likely(skb->next == NULL))
2207 		skb->destructor = DEV_GSO_CB(skb)->destructor;
2208 out_kfree_skb:
2209 	kfree_skb(skb);
2210 out:
2211 	return rc;
2212 }
2213 
2214 static u32 hashrnd __read_mostly;
2215 
2216 /*
2217  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
2218  * to be used as a distribution range.
2219  */
2220 u16 __skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb,
2221 		  unsigned int num_tx_queues)
2222 {
2223 	u32 hash;
2224 	u16 qoffset = 0;
2225 	u16 qcount = num_tx_queues;
2226 
2227 	if (skb_rx_queue_recorded(skb)) {
2228 		hash = skb_get_rx_queue(skb);
2229 		while (unlikely(hash >= num_tx_queues))
2230 			hash -= num_tx_queues;
2231 		return hash;
2232 	}
2233 
2234 	if (dev->num_tc) {
2235 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
2236 		qoffset = dev->tc_to_txq[tc].offset;
2237 		qcount = dev->tc_to_txq[tc].count;
2238 	}
2239 
2240 	if (skb->sk && skb->sk->sk_hash)
2241 		hash = skb->sk->sk_hash;
2242 	else
2243 		hash = (__force u16) skb->protocol ^ skb->rxhash;
2244 	hash = jhash_1word(hash, hashrnd);
2245 
2246 	return (u16) (((u64) hash * qcount) >> 32) + qoffset;
2247 }
2248 EXPORT_SYMBOL(__skb_tx_hash);
2249 
2250 static inline u16 dev_cap_txqueue(struct net_device *dev, u16 queue_index)
2251 {
2252 	if (unlikely(queue_index >= dev->real_num_tx_queues)) {
2253 		if (net_ratelimit()) {
2254 			pr_warning("%s selects TX queue %d, but "
2255 				"real number of TX queues is %d\n",
2256 				dev->name, queue_index, dev->real_num_tx_queues);
2257 		}
2258 		return 0;
2259 	}
2260 	return queue_index;
2261 }
2262 
2263 static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
2264 {
2265 #ifdef CONFIG_XPS
2266 	struct xps_dev_maps *dev_maps;
2267 	struct xps_map *map;
2268 	int queue_index = -1;
2269 
2270 	rcu_read_lock();
2271 	dev_maps = rcu_dereference(dev->xps_maps);
2272 	if (dev_maps) {
2273 		map = rcu_dereference(
2274 		    dev_maps->cpu_map[raw_smp_processor_id()]);
2275 		if (map) {
2276 			if (map->len == 1)
2277 				queue_index = map->queues[0];
2278 			else {
2279 				u32 hash;
2280 				if (skb->sk && skb->sk->sk_hash)
2281 					hash = skb->sk->sk_hash;
2282 				else
2283 					hash = (__force u16) skb->protocol ^
2284 					    skb->rxhash;
2285 				hash = jhash_1word(hash, hashrnd);
2286 				queue_index = map->queues[
2287 				    ((u64)hash * map->len) >> 32];
2288 			}
2289 			if (unlikely(queue_index >= dev->real_num_tx_queues))
2290 				queue_index = -1;
2291 		}
2292 	}
2293 	rcu_read_unlock();
2294 
2295 	return queue_index;
2296 #else
2297 	return -1;
2298 #endif
2299 }
2300 
2301 static struct netdev_queue *dev_pick_tx(struct net_device *dev,
2302 					struct sk_buff *skb)
2303 {
2304 	int queue_index;
2305 	const struct net_device_ops *ops = dev->netdev_ops;
2306 
2307 	if (dev->real_num_tx_queues == 1)
2308 		queue_index = 0;
2309 	else if (ops->ndo_select_queue) {
2310 		queue_index = ops->ndo_select_queue(dev, skb);
2311 		queue_index = dev_cap_txqueue(dev, queue_index);
2312 	} else {
2313 		struct sock *sk = skb->sk;
2314 		queue_index = sk_tx_queue_get(sk);
2315 
2316 		if (queue_index < 0 || skb->ooo_okay ||
2317 		    queue_index >= dev->real_num_tx_queues) {
2318 			int old_index = queue_index;
2319 
2320 			queue_index = get_xps_queue(dev, skb);
2321 			if (queue_index < 0)
2322 				queue_index = skb_tx_hash(dev, skb);
2323 
2324 			if (queue_index != old_index && sk) {
2325 				struct dst_entry *dst =
2326 				    rcu_dereference_check(sk->sk_dst_cache, 1);
2327 
2328 				if (dst && skb_dst(skb) == dst)
2329 					sk_tx_queue_set(sk, queue_index);
2330 			}
2331 		}
2332 	}
2333 
2334 	skb_set_queue_mapping(skb, queue_index);
2335 	return netdev_get_tx_queue(dev, queue_index);
2336 }
2337 
2338 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2339 				 struct net_device *dev,
2340 				 struct netdev_queue *txq)
2341 {
2342 	spinlock_t *root_lock = qdisc_lock(q);
2343 	bool contended;
2344 	int rc;
2345 
2346 	qdisc_skb_cb(skb)->pkt_len = skb->len;
2347 	qdisc_calculate_pkt_len(skb, q);
2348 	/*
2349 	 * Heuristic to force contended enqueues to serialize on a
2350 	 * separate lock before trying to get qdisc main lock.
2351 	 * This permits __QDISC_STATE_RUNNING owner to get the lock more often
2352 	 * and dequeue packets faster.
2353 	 */
2354 	contended = qdisc_is_running(q);
2355 	if (unlikely(contended))
2356 		spin_lock(&q->busylock);
2357 
2358 	spin_lock(root_lock);
2359 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2360 		kfree_skb(skb);
2361 		rc = NET_XMIT_DROP;
2362 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2363 		   qdisc_run_begin(q)) {
2364 		/*
2365 		 * This is a work-conserving queue; there are no old skbs
2366 		 * waiting to be sent out; and the qdisc is not running -
2367 		 * xmit the skb directly.
2368 		 */
2369 		if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2370 			skb_dst_force(skb);
2371 
2372 		qdisc_bstats_update(q, skb);
2373 
2374 		if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
2375 			if (unlikely(contended)) {
2376 				spin_unlock(&q->busylock);
2377 				contended = false;
2378 			}
2379 			__qdisc_run(q);
2380 		} else
2381 			qdisc_run_end(q);
2382 
2383 		rc = NET_XMIT_SUCCESS;
2384 	} else {
2385 		skb_dst_force(skb);
2386 		rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2387 		if (qdisc_run_begin(q)) {
2388 			if (unlikely(contended)) {
2389 				spin_unlock(&q->busylock);
2390 				contended = false;
2391 			}
2392 			__qdisc_run(q);
2393 		}
2394 	}
2395 	spin_unlock(root_lock);
2396 	if (unlikely(contended))
2397 		spin_unlock(&q->busylock);
2398 	return rc;
2399 }
2400 
2401 static DEFINE_PER_CPU(int, xmit_recursion);
2402 #define RECURSION_LIMIT 10
2403 
2404 /**
2405  *	dev_queue_xmit - transmit a buffer
2406  *	@skb: buffer to transmit
2407  *
2408  *	Queue a buffer for transmission to a network device. The caller must
2409  *	have set the device and priority and built the buffer before calling
2410  *	this function. The function can be called from an interrupt.
2411  *
2412  *	A negative errno code is returned on a failure. A success does not
2413  *	guarantee the frame will be transmitted as it may be dropped due
2414  *	to congestion or traffic shaping.
2415  *
2416  * -----------------------------------------------------------------------------------
2417  *      I notice this method can also return errors from the queue disciplines,
2418  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
2419  *      be positive.
2420  *
2421  *      Regardless of the return value, the skb is consumed, so it is currently
2422  *      difficult to retry a send to this method.  (You can bump the ref count
2423  *      before sending to hold a reference for retry if you are careful.)
2424  *
2425  *      When calling this method, interrupts MUST be enabled.  This is because
2426  *      the BH enable code must have IRQs enabled so that it will not deadlock.
2427  *          --BLG
2428  */
2429 int dev_queue_xmit(struct sk_buff *skb)
2430 {
2431 	struct net_device *dev = skb->dev;
2432 	struct netdev_queue *txq;
2433 	struct Qdisc *q;
2434 	int rc = -ENOMEM;
2435 
2436 	/* Disable soft irqs for various locks below. Also
2437 	 * stops preemption for RCU.
2438 	 */
2439 	rcu_read_lock_bh();
2440 
2441 	txq = dev_pick_tx(dev, skb);
2442 	q = rcu_dereference_bh(txq->qdisc);
2443 
2444 #ifdef CONFIG_NET_CLS_ACT
2445 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2446 #endif
2447 	trace_net_dev_queue(skb);
2448 	if (q->enqueue) {
2449 		rc = __dev_xmit_skb(skb, q, dev, txq);
2450 		goto out;
2451 	}
2452 
2453 	/* The device has no queue. Common case for software devices:
2454 	   loopback, all the sorts of tunnels...
2455 
2456 	   Really, it is unlikely that netif_tx_lock protection is necessary
2457 	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
2458 	   counters.)
2459 	   However, it is possible, that they rely on protection
2460 	   made by us here.
2461 
2462 	   Check this and shot the lock. It is not prone from deadlocks.
2463 	   Either shot noqueue qdisc, it is even simpler 8)
2464 	 */
2465 	if (dev->flags & IFF_UP) {
2466 		int cpu = smp_processor_id(); /* ok because BHs are off */
2467 
2468 		if (txq->xmit_lock_owner != cpu) {
2469 
2470 			if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
2471 				goto recursion_alert;
2472 
2473 			HARD_TX_LOCK(dev, txq, cpu);
2474 
2475 			if (!netif_tx_queue_stopped(txq)) {
2476 				__this_cpu_inc(xmit_recursion);
2477 				rc = dev_hard_start_xmit(skb, dev, txq);
2478 				__this_cpu_dec(xmit_recursion);
2479 				if (dev_xmit_complete(rc)) {
2480 					HARD_TX_UNLOCK(dev, txq);
2481 					goto out;
2482 				}
2483 			}
2484 			HARD_TX_UNLOCK(dev, txq);
2485 			if (net_ratelimit())
2486 				printk(KERN_CRIT "Virtual device %s asks to "
2487 				       "queue packet!\n", dev->name);
2488 		} else {
2489 			/* Recursion is detected! It is possible,
2490 			 * unfortunately
2491 			 */
2492 recursion_alert:
2493 			if (net_ratelimit())
2494 				printk(KERN_CRIT "Dead loop on virtual device "
2495 				       "%s, fix it urgently!\n", dev->name);
2496 		}
2497 	}
2498 
2499 	rc = -ENETDOWN;
2500 	rcu_read_unlock_bh();
2501 
2502 	kfree_skb(skb);
2503 	return rc;
2504 out:
2505 	rcu_read_unlock_bh();
2506 	return rc;
2507 }
2508 EXPORT_SYMBOL(dev_queue_xmit);
2509 
2510 
2511 /*=======================================================================
2512 			Receiver routines
2513   =======================================================================*/
2514 
2515 int netdev_max_backlog __read_mostly = 1000;
2516 int netdev_tstamp_prequeue __read_mostly = 1;
2517 int netdev_budget __read_mostly = 300;
2518 int weight_p __read_mostly = 64;            /* old backlog weight */
2519 
2520 /* Called with irq disabled */
2521 static inline void ____napi_schedule(struct softnet_data *sd,
2522 				     struct napi_struct *napi)
2523 {
2524 	list_add_tail(&napi->poll_list, &sd->poll_list);
2525 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2526 }
2527 
2528 /*
2529  * __skb_get_rxhash: calculate a flow hash based on src/dst addresses
2530  * and src/dst port numbers. Returns a non-zero hash number on success
2531  * and 0 on failure.
2532  */
2533 __u32 __skb_get_rxhash(struct sk_buff *skb)
2534 {
2535 	int nhoff, hash = 0, poff;
2536 	const struct ipv6hdr *ip6;
2537 	const struct iphdr *ip;
2538 	u8 ip_proto;
2539 	u32 addr1, addr2, ihl;
2540 	union {
2541 		u32 v32;
2542 		u16 v16[2];
2543 	} ports;
2544 
2545 	nhoff = skb_network_offset(skb);
2546 
2547 	switch (skb->protocol) {
2548 	case __constant_htons(ETH_P_IP):
2549 		if (!pskb_may_pull(skb, sizeof(*ip) + nhoff))
2550 			goto done;
2551 
2552 		ip = (const struct iphdr *) (skb->data + nhoff);
2553 		if (ip_is_fragment(ip))
2554 			ip_proto = 0;
2555 		else
2556 			ip_proto = ip->protocol;
2557 		addr1 = (__force u32) ip->saddr;
2558 		addr2 = (__force u32) ip->daddr;
2559 		ihl = ip->ihl;
2560 		break;
2561 	case __constant_htons(ETH_P_IPV6):
2562 		if (!pskb_may_pull(skb, sizeof(*ip6) + nhoff))
2563 			goto done;
2564 
2565 		ip6 = (const struct ipv6hdr *) (skb->data + nhoff);
2566 		ip_proto = ip6->nexthdr;
2567 		addr1 = (__force u32) ip6->saddr.s6_addr32[3];
2568 		addr2 = (__force u32) ip6->daddr.s6_addr32[3];
2569 		ihl = (40 >> 2);
2570 		break;
2571 	default:
2572 		goto done;
2573 	}
2574 
2575 	ports.v32 = 0;
2576 	poff = proto_ports_offset(ip_proto);
2577 	if (poff >= 0) {
2578 		nhoff += ihl * 4 + poff;
2579 		if (pskb_may_pull(skb, nhoff + 4)) {
2580 			ports.v32 = * (__force u32 *) (skb->data + nhoff);
2581 			if (ports.v16[1] < ports.v16[0])
2582 				swap(ports.v16[0], ports.v16[1]);
2583 		}
2584 	}
2585 
2586 	/* get a consistent hash (same value on both flow directions) */
2587 	if (addr2 < addr1)
2588 		swap(addr1, addr2);
2589 
2590 	hash = jhash_3words(addr1, addr2, ports.v32, hashrnd);
2591 	if (!hash)
2592 		hash = 1;
2593 
2594 done:
2595 	return hash;
2596 }
2597 EXPORT_SYMBOL(__skb_get_rxhash);
2598 
2599 #ifdef CONFIG_RPS
2600 
2601 /* One global table that all flow-based protocols share. */
2602 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2603 EXPORT_SYMBOL(rps_sock_flow_table);
2604 
2605 static struct rps_dev_flow *
2606 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2607 	    struct rps_dev_flow *rflow, u16 next_cpu)
2608 {
2609 	u16 tcpu;
2610 
2611 	tcpu = rflow->cpu = next_cpu;
2612 	if (tcpu != RPS_NO_CPU) {
2613 #ifdef CONFIG_RFS_ACCEL
2614 		struct netdev_rx_queue *rxqueue;
2615 		struct rps_dev_flow_table *flow_table;
2616 		struct rps_dev_flow *old_rflow;
2617 		u32 flow_id;
2618 		u16 rxq_index;
2619 		int rc;
2620 
2621 		/* Should we steer this flow to a different hardware queue? */
2622 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
2623 		    !(dev->features & NETIF_F_NTUPLE))
2624 			goto out;
2625 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
2626 		if (rxq_index == skb_get_rx_queue(skb))
2627 			goto out;
2628 
2629 		rxqueue = dev->_rx + rxq_index;
2630 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
2631 		if (!flow_table)
2632 			goto out;
2633 		flow_id = skb->rxhash & flow_table->mask;
2634 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
2635 							rxq_index, flow_id);
2636 		if (rc < 0)
2637 			goto out;
2638 		old_rflow = rflow;
2639 		rflow = &flow_table->flows[flow_id];
2640 		rflow->cpu = next_cpu;
2641 		rflow->filter = rc;
2642 		if (old_rflow->filter == rflow->filter)
2643 			old_rflow->filter = RPS_NO_FILTER;
2644 	out:
2645 #endif
2646 		rflow->last_qtail =
2647 			per_cpu(softnet_data, tcpu).input_queue_head;
2648 	}
2649 
2650 	return rflow;
2651 }
2652 
2653 /*
2654  * get_rps_cpu is called from netif_receive_skb and returns the target
2655  * CPU from the RPS map of the receiving queue for a given skb.
2656  * rcu_read_lock must be held on entry.
2657  */
2658 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2659 		       struct rps_dev_flow **rflowp)
2660 {
2661 	struct netdev_rx_queue *rxqueue;
2662 	struct rps_map *map;
2663 	struct rps_dev_flow_table *flow_table;
2664 	struct rps_sock_flow_table *sock_flow_table;
2665 	int cpu = -1;
2666 	u16 tcpu;
2667 
2668 	if (skb_rx_queue_recorded(skb)) {
2669 		u16 index = skb_get_rx_queue(skb);
2670 		if (unlikely(index >= dev->real_num_rx_queues)) {
2671 			WARN_ONCE(dev->real_num_rx_queues > 1,
2672 				  "%s received packet on queue %u, but number "
2673 				  "of RX queues is %u\n",
2674 				  dev->name, index, dev->real_num_rx_queues);
2675 			goto done;
2676 		}
2677 		rxqueue = dev->_rx + index;
2678 	} else
2679 		rxqueue = dev->_rx;
2680 
2681 	map = rcu_dereference(rxqueue->rps_map);
2682 	if (map) {
2683 		if (map->len == 1 &&
2684 		    !rcu_dereference_raw(rxqueue->rps_flow_table)) {
2685 			tcpu = map->cpus[0];
2686 			if (cpu_online(tcpu))
2687 				cpu = tcpu;
2688 			goto done;
2689 		}
2690 	} else if (!rcu_dereference_raw(rxqueue->rps_flow_table)) {
2691 		goto done;
2692 	}
2693 
2694 	skb_reset_network_header(skb);
2695 	if (!skb_get_rxhash(skb))
2696 		goto done;
2697 
2698 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
2699 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
2700 	if (flow_table && sock_flow_table) {
2701 		u16 next_cpu;
2702 		struct rps_dev_flow *rflow;
2703 
2704 		rflow = &flow_table->flows[skb->rxhash & flow_table->mask];
2705 		tcpu = rflow->cpu;
2706 
2707 		next_cpu = sock_flow_table->ents[skb->rxhash &
2708 		    sock_flow_table->mask];
2709 
2710 		/*
2711 		 * If the desired CPU (where last recvmsg was done) is
2712 		 * different from current CPU (one in the rx-queue flow
2713 		 * table entry), switch if one of the following holds:
2714 		 *   - Current CPU is unset (equal to RPS_NO_CPU).
2715 		 *   - Current CPU is offline.
2716 		 *   - The current CPU's queue tail has advanced beyond the
2717 		 *     last packet that was enqueued using this table entry.
2718 		 *     This guarantees that all previous packets for the flow
2719 		 *     have been dequeued, thus preserving in order delivery.
2720 		 */
2721 		if (unlikely(tcpu != next_cpu) &&
2722 		    (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
2723 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
2724 		      rflow->last_qtail)) >= 0))
2725 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
2726 
2727 		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
2728 			*rflowp = rflow;
2729 			cpu = tcpu;
2730 			goto done;
2731 		}
2732 	}
2733 
2734 	if (map) {
2735 		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
2736 
2737 		if (cpu_online(tcpu)) {
2738 			cpu = tcpu;
2739 			goto done;
2740 		}
2741 	}
2742 
2743 done:
2744 	return cpu;
2745 }
2746 
2747 #ifdef CONFIG_RFS_ACCEL
2748 
2749 /**
2750  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
2751  * @dev: Device on which the filter was set
2752  * @rxq_index: RX queue index
2753  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
2754  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
2755  *
2756  * Drivers that implement ndo_rx_flow_steer() should periodically call
2757  * this function for each installed filter and remove the filters for
2758  * which it returns %true.
2759  */
2760 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
2761 			 u32 flow_id, u16 filter_id)
2762 {
2763 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
2764 	struct rps_dev_flow_table *flow_table;
2765 	struct rps_dev_flow *rflow;
2766 	bool expire = true;
2767 	int cpu;
2768 
2769 	rcu_read_lock();
2770 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
2771 	if (flow_table && flow_id <= flow_table->mask) {
2772 		rflow = &flow_table->flows[flow_id];
2773 		cpu = ACCESS_ONCE(rflow->cpu);
2774 		if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
2775 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
2776 			   rflow->last_qtail) <
2777 		     (int)(10 * flow_table->mask)))
2778 			expire = false;
2779 	}
2780 	rcu_read_unlock();
2781 	return expire;
2782 }
2783 EXPORT_SYMBOL(rps_may_expire_flow);
2784 
2785 #endif /* CONFIG_RFS_ACCEL */
2786 
2787 /* Called from hardirq (IPI) context */
2788 static void rps_trigger_softirq(void *data)
2789 {
2790 	struct softnet_data *sd = data;
2791 
2792 	____napi_schedule(sd, &sd->backlog);
2793 	sd->received_rps++;
2794 }
2795 
2796 #endif /* CONFIG_RPS */
2797 
2798 /*
2799  * Check if this softnet_data structure is another cpu one
2800  * If yes, queue it to our IPI list and return 1
2801  * If no, return 0
2802  */
2803 static int rps_ipi_queued(struct softnet_data *sd)
2804 {
2805 #ifdef CONFIG_RPS
2806 	struct softnet_data *mysd = &__get_cpu_var(softnet_data);
2807 
2808 	if (sd != mysd) {
2809 		sd->rps_ipi_next = mysd->rps_ipi_list;
2810 		mysd->rps_ipi_list = sd;
2811 
2812 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2813 		return 1;
2814 	}
2815 #endif /* CONFIG_RPS */
2816 	return 0;
2817 }
2818 
2819 /*
2820  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
2821  * queue (may be a remote CPU queue).
2822  */
2823 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
2824 			      unsigned int *qtail)
2825 {
2826 	struct softnet_data *sd;
2827 	unsigned long flags;
2828 
2829 	sd = &per_cpu(softnet_data, cpu);
2830 
2831 	local_irq_save(flags);
2832 
2833 	rps_lock(sd);
2834 	if (skb_queue_len(&sd->input_pkt_queue) <= netdev_max_backlog) {
2835 		if (skb_queue_len(&sd->input_pkt_queue)) {
2836 enqueue:
2837 			__skb_queue_tail(&sd->input_pkt_queue, skb);
2838 			input_queue_tail_incr_save(sd, qtail);
2839 			rps_unlock(sd);
2840 			local_irq_restore(flags);
2841 			return NET_RX_SUCCESS;
2842 		}
2843 
2844 		/* Schedule NAPI for backlog device
2845 		 * We can use non atomic operation since we own the queue lock
2846 		 */
2847 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
2848 			if (!rps_ipi_queued(sd))
2849 				____napi_schedule(sd, &sd->backlog);
2850 		}
2851 		goto enqueue;
2852 	}
2853 
2854 	sd->dropped++;
2855 	rps_unlock(sd);
2856 
2857 	local_irq_restore(flags);
2858 
2859 	atomic_long_inc(&skb->dev->rx_dropped);
2860 	kfree_skb(skb);
2861 	return NET_RX_DROP;
2862 }
2863 
2864 /**
2865  *	netif_rx	-	post buffer to the network code
2866  *	@skb: buffer to post
2867  *
2868  *	This function receives a packet from a device driver and queues it for
2869  *	the upper (protocol) levels to process.  It always succeeds. The buffer
2870  *	may be dropped during processing for congestion control or by the
2871  *	protocol layers.
2872  *
2873  *	return values:
2874  *	NET_RX_SUCCESS	(no congestion)
2875  *	NET_RX_DROP     (packet was dropped)
2876  *
2877  */
2878 
2879 int netif_rx(struct sk_buff *skb)
2880 {
2881 	int ret;
2882 
2883 	/* if netpoll wants it, pretend we never saw it */
2884 	if (netpoll_rx(skb))
2885 		return NET_RX_DROP;
2886 
2887 	if (netdev_tstamp_prequeue)
2888 		net_timestamp_check(skb);
2889 
2890 	trace_netif_rx(skb);
2891 #ifdef CONFIG_RPS
2892 	{
2893 		struct rps_dev_flow voidflow, *rflow = &voidflow;
2894 		int cpu;
2895 
2896 		preempt_disable();
2897 		rcu_read_lock();
2898 
2899 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
2900 		if (cpu < 0)
2901 			cpu = smp_processor_id();
2902 
2903 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
2904 
2905 		rcu_read_unlock();
2906 		preempt_enable();
2907 	}
2908 #else
2909 	{
2910 		unsigned int qtail;
2911 		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
2912 		put_cpu();
2913 	}
2914 #endif
2915 	return ret;
2916 }
2917 EXPORT_SYMBOL(netif_rx);
2918 
2919 int netif_rx_ni(struct sk_buff *skb)
2920 {
2921 	int err;
2922 
2923 	preempt_disable();
2924 	err = netif_rx(skb);
2925 	if (local_softirq_pending())
2926 		do_softirq();
2927 	preempt_enable();
2928 
2929 	return err;
2930 }
2931 EXPORT_SYMBOL(netif_rx_ni);
2932 
2933 static void net_tx_action(struct softirq_action *h)
2934 {
2935 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
2936 
2937 	if (sd->completion_queue) {
2938 		struct sk_buff *clist;
2939 
2940 		local_irq_disable();
2941 		clist = sd->completion_queue;
2942 		sd->completion_queue = NULL;
2943 		local_irq_enable();
2944 
2945 		while (clist) {
2946 			struct sk_buff *skb = clist;
2947 			clist = clist->next;
2948 
2949 			WARN_ON(atomic_read(&skb->users));
2950 			trace_kfree_skb(skb, net_tx_action);
2951 			__kfree_skb(skb);
2952 		}
2953 	}
2954 
2955 	if (sd->output_queue) {
2956 		struct Qdisc *head;
2957 
2958 		local_irq_disable();
2959 		head = sd->output_queue;
2960 		sd->output_queue = NULL;
2961 		sd->output_queue_tailp = &sd->output_queue;
2962 		local_irq_enable();
2963 
2964 		while (head) {
2965 			struct Qdisc *q = head;
2966 			spinlock_t *root_lock;
2967 
2968 			head = head->next_sched;
2969 
2970 			root_lock = qdisc_lock(q);
2971 			if (spin_trylock(root_lock)) {
2972 				smp_mb__before_clear_bit();
2973 				clear_bit(__QDISC_STATE_SCHED,
2974 					  &q->state);
2975 				qdisc_run(q);
2976 				spin_unlock(root_lock);
2977 			} else {
2978 				if (!test_bit(__QDISC_STATE_DEACTIVATED,
2979 					      &q->state)) {
2980 					__netif_reschedule(q);
2981 				} else {
2982 					smp_mb__before_clear_bit();
2983 					clear_bit(__QDISC_STATE_SCHED,
2984 						  &q->state);
2985 				}
2986 			}
2987 		}
2988 	}
2989 }
2990 
2991 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
2992     (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
2993 /* This hook is defined here for ATM LANE */
2994 int (*br_fdb_test_addr_hook)(struct net_device *dev,
2995 			     unsigned char *addr) __read_mostly;
2996 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
2997 #endif
2998 
2999 #ifdef CONFIG_NET_CLS_ACT
3000 /* TODO: Maybe we should just force sch_ingress to be compiled in
3001  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
3002  * a compare and 2 stores extra right now if we dont have it on
3003  * but have CONFIG_NET_CLS_ACT
3004  * NOTE: This doesn't stop any functionality; if you dont have
3005  * the ingress scheduler, you just can't add policies on ingress.
3006  *
3007  */
3008 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
3009 {
3010 	struct net_device *dev = skb->dev;
3011 	u32 ttl = G_TC_RTTL(skb->tc_verd);
3012 	int result = TC_ACT_OK;
3013 	struct Qdisc *q;
3014 
3015 	if (unlikely(MAX_RED_LOOP < ttl++)) {
3016 		if (net_ratelimit())
3017 			pr_warning( "Redir loop detected Dropping packet (%d->%d)\n",
3018 			       skb->skb_iif, dev->ifindex);
3019 		return TC_ACT_SHOT;
3020 	}
3021 
3022 	skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
3023 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
3024 
3025 	q = rxq->qdisc;
3026 	if (q != &noop_qdisc) {
3027 		spin_lock(qdisc_lock(q));
3028 		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
3029 			result = qdisc_enqueue_root(skb, q);
3030 		spin_unlock(qdisc_lock(q));
3031 	}
3032 
3033 	return result;
3034 }
3035 
3036 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
3037 					 struct packet_type **pt_prev,
3038 					 int *ret, struct net_device *orig_dev)
3039 {
3040 	struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
3041 
3042 	if (!rxq || rxq->qdisc == &noop_qdisc)
3043 		goto out;
3044 
3045 	if (*pt_prev) {
3046 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
3047 		*pt_prev = NULL;
3048 	}
3049 
3050 	switch (ing_filter(skb, rxq)) {
3051 	case TC_ACT_SHOT:
3052 	case TC_ACT_STOLEN:
3053 		kfree_skb(skb);
3054 		return NULL;
3055 	}
3056 
3057 out:
3058 	skb->tc_verd = 0;
3059 	return skb;
3060 }
3061 #endif
3062 
3063 /**
3064  *	netdev_rx_handler_register - register receive handler
3065  *	@dev: device to register a handler for
3066  *	@rx_handler: receive handler to register
3067  *	@rx_handler_data: data pointer that is used by rx handler
3068  *
3069  *	Register a receive hander for a device. This handler will then be
3070  *	called from __netif_receive_skb. A negative errno code is returned
3071  *	on a failure.
3072  *
3073  *	The caller must hold the rtnl_mutex.
3074  *
3075  *	For a general description of rx_handler, see enum rx_handler_result.
3076  */
3077 int netdev_rx_handler_register(struct net_device *dev,
3078 			       rx_handler_func_t *rx_handler,
3079 			       void *rx_handler_data)
3080 {
3081 	ASSERT_RTNL();
3082 
3083 	if (dev->rx_handler)
3084 		return -EBUSY;
3085 
3086 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3087 	rcu_assign_pointer(dev->rx_handler, rx_handler);
3088 
3089 	return 0;
3090 }
3091 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
3092 
3093 /**
3094  *	netdev_rx_handler_unregister - unregister receive handler
3095  *	@dev: device to unregister a handler from
3096  *
3097  *	Unregister a receive hander from a device.
3098  *
3099  *	The caller must hold the rtnl_mutex.
3100  */
3101 void netdev_rx_handler_unregister(struct net_device *dev)
3102 {
3103 
3104 	ASSERT_RTNL();
3105 	rcu_assign_pointer(dev->rx_handler, NULL);
3106 	rcu_assign_pointer(dev->rx_handler_data, NULL);
3107 }
3108 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
3109 
3110 static int __netif_receive_skb(struct sk_buff *skb)
3111 {
3112 	struct packet_type *ptype, *pt_prev;
3113 	rx_handler_func_t *rx_handler;
3114 	struct net_device *orig_dev;
3115 	struct net_device *null_or_dev;
3116 	bool deliver_exact = false;
3117 	int ret = NET_RX_DROP;
3118 	__be16 type;
3119 
3120 	if (!netdev_tstamp_prequeue)
3121 		net_timestamp_check(skb);
3122 
3123 	trace_netif_receive_skb(skb);
3124 
3125 	/* if we've gotten here through NAPI, check netpoll */
3126 	if (netpoll_receive_skb(skb))
3127 		return NET_RX_DROP;
3128 
3129 	if (!skb->skb_iif)
3130 		skb->skb_iif = skb->dev->ifindex;
3131 	orig_dev = skb->dev;
3132 
3133 	skb_reset_network_header(skb);
3134 	skb_reset_transport_header(skb);
3135 	skb_reset_mac_len(skb);
3136 
3137 	pt_prev = NULL;
3138 
3139 	rcu_read_lock();
3140 
3141 another_round:
3142 
3143 	__this_cpu_inc(softnet_data.processed);
3144 
3145 	if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
3146 		skb = vlan_untag(skb);
3147 		if (unlikely(!skb))
3148 			goto out;
3149 	}
3150 
3151 #ifdef CONFIG_NET_CLS_ACT
3152 	if (skb->tc_verd & TC_NCLS) {
3153 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
3154 		goto ncls;
3155 	}
3156 #endif
3157 
3158 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
3159 		if (!ptype->dev || ptype->dev == skb->dev) {
3160 			if (pt_prev)
3161 				ret = deliver_skb(skb, pt_prev, orig_dev);
3162 			pt_prev = ptype;
3163 		}
3164 	}
3165 
3166 #ifdef CONFIG_NET_CLS_ACT
3167 	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
3168 	if (!skb)
3169 		goto out;
3170 ncls:
3171 #endif
3172 
3173 	rx_handler = rcu_dereference(skb->dev->rx_handler);
3174 	if (rx_handler) {
3175 		if (pt_prev) {
3176 			ret = deliver_skb(skb, pt_prev, orig_dev);
3177 			pt_prev = NULL;
3178 		}
3179 		switch (rx_handler(&skb)) {
3180 		case RX_HANDLER_CONSUMED:
3181 			goto out;
3182 		case RX_HANDLER_ANOTHER:
3183 			goto another_round;
3184 		case RX_HANDLER_EXACT:
3185 			deliver_exact = true;
3186 		case RX_HANDLER_PASS:
3187 			break;
3188 		default:
3189 			BUG();
3190 		}
3191 	}
3192 
3193 	if (vlan_tx_tag_present(skb)) {
3194 		if (pt_prev) {
3195 			ret = deliver_skb(skb, pt_prev, orig_dev);
3196 			pt_prev = NULL;
3197 		}
3198 		if (vlan_do_receive(&skb)) {
3199 			ret = __netif_receive_skb(skb);
3200 			goto out;
3201 		} else if (unlikely(!skb))
3202 			goto out;
3203 	}
3204 
3205 	/* deliver only exact match when indicated */
3206 	null_or_dev = deliver_exact ? skb->dev : NULL;
3207 
3208 	type = skb->protocol;
3209 	list_for_each_entry_rcu(ptype,
3210 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3211 		if (ptype->type == type &&
3212 		    (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
3213 		     ptype->dev == orig_dev)) {
3214 			if (pt_prev)
3215 				ret = deliver_skb(skb, pt_prev, orig_dev);
3216 			pt_prev = ptype;
3217 		}
3218 	}
3219 
3220 	if (pt_prev) {
3221 		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
3222 	} else {
3223 		atomic_long_inc(&skb->dev->rx_dropped);
3224 		kfree_skb(skb);
3225 		/* Jamal, now you will not able to escape explaining
3226 		 * me how you were going to use this. :-)
3227 		 */
3228 		ret = NET_RX_DROP;
3229 	}
3230 
3231 out:
3232 	rcu_read_unlock();
3233 	return ret;
3234 }
3235 
3236 /**
3237  *	netif_receive_skb - process receive buffer from network
3238  *	@skb: buffer to process
3239  *
3240  *	netif_receive_skb() is the main receive data processing function.
3241  *	It always succeeds. The buffer may be dropped during processing
3242  *	for congestion control or by the protocol layers.
3243  *
3244  *	This function may only be called from softirq context and interrupts
3245  *	should be enabled.
3246  *
3247  *	Return values (usually ignored):
3248  *	NET_RX_SUCCESS: no congestion
3249  *	NET_RX_DROP: packet was dropped
3250  */
3251 int netif_receive_skb(struct sk_buff *skb)
3252 {
3253 	if (netdev_tstamp_prequeue)
3254 		net_timestamp_check(skb);
3255 
3256 	if (skb_defer_rx_timestamp(skb))
3257 		return NET_RX_SUCCESS;
3258 
3259 #ifdef CONFIG_RPS
3260 	{
3261 		struct rps_dev_flow voidflow, *rflow = &voidflow;
3262 		int cpu, ret;
3263 
3264 		rcu_read_lock();
3265 
3266 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3267 
3268 		if (cpu >= 0) {
3269 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3270 			rcu_read_unlock();
3271 		} else {
3272 			rcu_read_unlock();
3273 			ret = __netif_receive_skb(skb);
3274 		}
3275 
3276 		return ret;
3277 	}
3278 #else
3279 	return __netif_receive_skb(skb);
3280 #endif
3281 }
3282 EXPORT_SYMBOL(netif_receive_skb);
3283 
3284 /* Network device is going away, flush any packets still pending
3285  * Called with irqs disabled.
3286  */
3287 static void flush_backlog(void *arg)
3288 {
3289 	struct net_device *dev = arg;
3290 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3291 	struct sk_buff *skb, *tmp;
3292 
3293 	rps_lock(sd);
3294 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3295 		if (skb->dev == dev) {
3296 			__skb_unlink(skb, &sd->input_pkt_queue);
3297 			kfree_skb(skb);
3298 			input_queue_head_incr(sd);
3299 		}
3300 	}
3301 	rps_unlock(sd);
3302 
3303 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
3304 		if (skb->dev == dev) {
3305 			__skb_unlink(skb, &sd->process_queue);
3306 			kfree_skb(skb);
3307 			input_queue_head_incr(sd);
3308 		}
3309 	}
3310 }
3311 
3312 static int napi_gro_complete(struct sk_buff *skb)
3313 {
3314 	struct packet_type *ptype;
3315 	__be16 type = skb->protocol;
3316 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
3317 	int err = -ENOENT;
3318 
3319 	if (NAPI_GRO_CB(skb)->count == 1) {
3320 		skb_shinfo(skb)->gso_size = 0;
3321 		goto out;
3322 	}
3323 
3324 	rcu_read_lock();
3325 	list_for_each_entry_rcu(ptype, head, list) {
3326 		if (ptype->type != type || ptype->dev || !ptype->gro_complete)
3327 			continue;
3328 
3329 		err = ptype->gro_complete(skb);
3330 		break;
3331 	}
3332 	rcu_read_unlock();
3333 
3334 	if (err) {
3335 		WARN_ON(&ptype->list == head);
3336 		kfree_skb(skb);
3337 		return NET_RX_SUCCESS;
3338 	}
3339 
3340 out:
3341 	return netif_receive_skb(skb);
3342 }
3343 
3344 inline void napi_gro_flush(struct napi_struct *napi)
3345 {
3346 	struct sk_buff *skb, *next;
3347 
3348 	for (skb = napi->gro_list; skb; skb = next) {
3349 		next = skb->next;
3350 		skb->next = NULL;
3351 		napi_gro_complete(skb);
3352 	}
3353 
3354 	napi->gro_count = 0;
3355 	napi->gro_list = NULL;
3356 }
3357 EXPORT_SYMBOL(napi_gro_flush);
3358 
3359 enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3360 {
3361 	struct sk_buff **pp = NULL;
3362 	struct packet_type *ptype;
3363 	__be16 type = skb->protocol;
3364 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
3365 	int same_flow;
3366 	int mac_len;
3367 	enum gro_result ret;
3368 
3369 	if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3370 		goto normal;
3371 
3372 	if (skb_is_gso(skb) || skb_has_frag_list(skb))
3373 		goto normal;
3374 
3375 	rcu_read_lock();
3376 	list_for_each_entry_rcu(ptype, head, list) {
3377 		if (ptype->type != type || ptype->dev || !ptype->gro_receive)
3378 			continue;
3379 
3380 		skb_set_network_header(skb, skb_gro_offset(skb));
3381 		mac_len = skb->network_header - skb->mac_header;
3382 		skb->mac_len = mac_len;
3383 		NAPI_GRO_CB(skb)->same_flow = 0;
3384 		NAPI_GRO_CB(skb)->flush = 0;
3385 		NAPI_GRO_CB(skb)->free = 0;
3386 
3387 		pp = ptype->gro_receive(&napi->gro_list, skb);
3388 		break;
3389 	}
3390 	rcu_read_unlock();
3391 
3392 	if (&ptype->list == head)
3393 		goto normal;
3394 
3395 	same_flow = NAPI_GRO_CB(skb)->same_flow;
3396 	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3397 
3398 	if (pp) {
3399 		struct sk_buff *nskb = *pp;
3400 
3401 		*pp = nskb->next;
3402 		nskb->next = NULL;
3403 		napi_gro_complete(nskb);
3404 		napi->gro_count--;
3405 	}
3406 
3407 	if (same_flow)
3408 		goto ok;
3409 
3410 	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3411 		goto normal;
3412 
3413 	napi->gro_count++;
3414 	NAPI_GRO_CB(skb)->count = 1;
3415 	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3416 	skb->next = napi->gro_list;
3417 	napi->gro_list = skb;
3418 	ret = GRO_HELD;
3419 
3420 pull:
3421 	if (skb_headlen(skb) < skb_gro_offset(skb)) {
3422 		int grow = skb_gro_offset(skb) - skb_headlen(skb);
3423 
3424 		BUG_ON(skb->end - skb->tail < grow);
3425 
3426 		memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3427 
3428 		skb->tail += grow;
3429 		skb->data_len -= grow;
3430 
3431 		skb_shinfo(skb)->frags[0].page_offset += grow;
3432 		skb_shinfo(skb)->frags[0].size -= grow;
3433 
3434 		if (unlikely(!skb_shinfo(skb)->frags[0].size)) {
3435 			put_page(skb_shinfo(skb)->frags[0].page);
3436 			memmove(skb_shinfo(skb)->frags,
3437 				skb_shinfo(skb)->frags + 1,
3438 				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
3439 		}
3440 	}
3441 
3442 ok:
3443 	return ret;
3444 
3445 normal:
3446 	ret = GRO_NORMAL;
3447 	goto pull;
3448 }
3449 EXPORT_SYMBOL(dev_gro_receive);
3450 
3451 static inline gro_result_t
3452 __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3453 {
3454 	struct sk_buff *p;
3455 
3456 	for (p = napi->gro_list; p; p = p->next) {
3457 		unsigned long diffs;
3458 
3459 		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
3460 		diffs |= p->vlan_tci ^ skb->vlan_tci;
3461 		diffs |= compare_ether_header(skb_mac_header(p),
3462 					      skb_gro_mac_header(skb));
3463 		NAPI_GRO_CB(p)->same_flow = !diffs;
3464 		NAPI_GRO_CB(p)->flush = 0;
3465 	}
3466 
3467 	return dev_gro_receive(napi, skb);
3468 }
3469 
3470 gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
3471 {
3472 	switch (ret) {
3473 	case GRO_NORMAL:
3474 		if (netif_receive_skb(skb))
3475 			ret = GRO_DROP;
3476 		break;
3477 
3478 	case GRO_DROP:
3479 	case GRO_MERGED_FREE:
3480 		kfree_skb(skb);
3481 		break;
3482 
3483 	case GRO_HELD:
3484 	case GRO_MERGED:
3485 		break;
3486 	}
3487 
3488 	return ret;
3489 }
3490 EXPORT_SYMBOL(napi_skb_finish);
3491 
3492 void skb_gro_reset_offset(struct sk_buff *skb)
3493 {
3494 	NAPI_GRO_CB(skb)->data_offset = 0;
3495 	NAPI_GRO_CB(skb)->frag0 = NULL;
3496 	NAPI_GRO_CB(skb)->frag0_len = 0;
3497 
3498 	if (skb->mac_header == skb->tail &&
3499 	    !PageHighMem(skb_shinfo(skb)->frags[0].page)) {
3500 		NAPI_GRO_CB(skb)->frag0 =
3501 			page_address(skb_shinfo(skb)->frags[0].page) +
3502 			skb_shinfo(skb)->frags[0].page_offset;
3503 		NAPI_GRO_CB(skb)->frag0_len = skb_shinfo(skb)->frags[0].size;
3504 	}
3505 }
3506 EXPORT_SYMBOL(skb_gro_reset_offset);
3507 
3508 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3509 {
3510 	skb_gro_reset_offset(skb);
3511 
3512 	return napi_skb_finish(__napi_gro_receive(napi, skb), skb);
3513 }
3514 EXPORT_SYMBOL(napi_gro_receive);
3515 
3516 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3517 {
3518 	__skb_pull(skb, skb_headlen(skb));
3519 	skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb));
3520 	skb->vlan_tci = 0;
3521 	skb->dev = napi->dev;
3522 	skb->skb_iif = 0;
3523 
3524 	napi->skb = skb;
3525 }
3526 
3527 struct sk_buff *napi_get_frags(struct napi_struct *napi)
3528 {
3529 	struct sk_buff *skb = napi->skb;
3530 
3531 	if (!skb) {
3532 		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
3533 		if (skb)
3534 			napi->skb = skb;
3535 	}
3536 	return skb;
3537 }
3538 EXPORT_SYMBOL(napi_get_frags);
3539 
3540 gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3541 			       gro_result_t ret)
3542 {
3543 	switch (ret) {
3544 	case GRO_NORMAL:
3545 	case GRO_HELD:
3546 		skb->protocol = eth_type_trans(skb, skb->dev);
3547 
3548 		if (ret == GRO_HELD)
3549 			skb_gro_pull(skb, -ETH_HLEN);
3550 		else if (netif_receive_skb(skb))
3551 			ret = GRO_DROP;
3552 		break;
3553 
3554 	case GRO_DROP:
3555 	case GRO_MERGED_FREE:
3556 		napi_reuse_skb(napi, skb);
3557 		break;
3558 
3559 	case GRO_MERGED:
3560 		break;
3561 	}
3562 
3563 	return ret;
3564 }
3565 EXPORT_SYMBOL(napi_frags_finish);
3566 
3567 struct sk_buff *napi_frags_skb(struct napi_struct *napi)
3568 {
3569 	struct sk_buff *skb = napi->skb;
3570 	struct ethhdr *eth;
3571 	unsigned int hlen;
3572 	unsigned int off;
3573 
3574 	napi->skb = NULL;
3575 
3576 	skb_reset_mac_header(skb);
3577 	skb_gro_reset_offset(skb);
3578 
3579 	off = skb_gro_offset(skb);
3580 	hlen = off + sizeof(*eth);
3581 	eth = skb_gro_header_fast(skb, off);
3582 	if (skb_gro_header_hard(skb, hlen)) {
3583 		eth = skb_gro_header_slow(skb, hlen, off);
3584 		if (unlikely(!eth)) {
3585 			napi_reuse_skb(napi, skb);
3586 			skb = NULL;
3587 			goto out;
3588 		}
3589 	}
3590 
3591 	skb_gro_pull(skb, sizeof(*eth));
3592 
3593 	/*
3594 	 * This works because the only protocols we care about don't require
3595 	 * special handling.  We'll fix it up properly at the end.
3596 	 */
3597 	skb->protocol = eth->h_proto;
3598 
3599 out:
3600 	return skb;
3601 }
3602 EXPORT_SYMBOL(napi_frags_skb);
3603 
3604 gro_result_t napi_gro_frags(struct napi_struct *napi)
3605 {
3606 	struct sk_buff *skb = napi_frags_skb(napi);
3607 
3608 	if (!skb)
3609 		return GRO_DROP;
3610 
3611 	return napi_frags_finish(napi, skb, __napi_gro_receive(napi, skb));
3612 }
3613 EXPORT_SYMBOL(napi_gro_frags);
3614 
3615 /*
3616  * net_rps_action sends any pending IPI's for rps.
3617  * Note: called with local irq disabled, but exits with local irq enabled.
3618  */
3619 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
3620 {
3621 #ifdef CONFIG_RPS
3622 	struct softnet_data *remsd = sd->rps_ipi_list;
3623 
3624 	if (remsd) {
3625 		sd->rps_ipi_list = NULL;
3626 
3627 		local_irq_enable();
3628 
3629 		/* Send pending IPI's to kick RPS processing on remote cpus. */
3630 		while (remsd) {
3631 			struct softnet_data *next = remsd->rps_ipi_next;
3632 
3633 			if (cpu_online(remsd->cpu))
3634 				__smp_call_function_single(remsd->cpu,
3635 							   &remsd->csd, 0);
3636 			remsd = next;
3637 		}
3638 	} else
3639 #endif
3640 		local_irq_enable();
3641 }
3642 
3643 static int process_backlog(struct napi_struct *napi, int quota)
3644 {
3645 	int work = 0;
3646 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
3647 
3648 #ifdef CONFIG_RPS
3649 	/* Check if we have pending ipi, its better to send them now,
3650 	 * not waiting net_rx_action() end.
3651 	 */
3652 	if (sd->rps_ipi_list) {
3653 		local_irq_disable();
3654 		net_rps_action_and_irq_enable(sd);
3655 	}
3656 #endif
3657 	napi->weight = weight_p;
3658 	local_irq_disable();
3659 	while (work < quota) {
3660 		struct sk_buff *skb;
3661 		unsigned int qlen;
3662 
3663 		while ((skb = __skb_dequeue(&sd->process_queue))) {
3664 			local_irq_enable();
3665 			__netif_receive_skb(skb);
3666 			local_irq_disable();
3667 			input_queue_head_incr(sd);
3668 			if (++work >= quota) {
3669 				local_irq_enable();
3670 				return work;
3671 			}
3672 		}
3673 
3674 		rps_lock(sd);
3675 		qlen = skb_queue_len(&sd->input_pkt_queue);
3676 		if (qlen)
3677 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
3678 						   &sd->process_queue);
3679 
3680 		if (qlen < quota - work) {
3681 			/*
3682 			 * Inline a custom version of __napi_complete().
3683 			 * only current cpu owns and manipulates this napi,
3684 			 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
3685 			 * we can use a plain write instead of clear_bit(),
3686 			 * and we dont need an smp_mb() memory barrier.
3687 			 */
3688 			list_del(&napi->poll_list);
3689 			napi->state = 0;
3690 
3691 			quota = work + qlen;
3692 		}
3693 		rps_unlock(sd);
3694 	}
3695 	local_irq_enable();
3696 
3697 	return work;
3698 }
3699 
3700 /**
3701  * __napi_schedule - schedule for receive
3702  * @n: entry to schedule
3703  *
3704  * The entry's receive function will be scheduled to run
3705  */
3706 void __napi_schedule(struct napi_struct *n)
3707 {
3708 	unsigned long flags;
3709 
3710 	local_irq_save(flags);
3711 	____napi_schedule(&__get_cpu_var(softnet_data), n);
3712 	local_irq_restore(flags);
3713 }
3714 EXPORT_SYMBOL(__napi_schedule);
3715 
3716 void __napi_complete(struct napi_struct *n)
3717 {
3718 	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
3719 	BUG_ON(n->gro_list);
3720 
3721 	list_del(&n->poll_list);
3722 	smp_mb__before_clear_bit();
3723 	clear_bit(NAPI_STATE_SCHED, &n->state);
3724 }
3725 EXPORT_SYMBOL(__napi_complete);
3726 
3727 void napi_complete(struct napi_struct *n)
3728 {
3729 	unsigned long flags;
3730 
3731 	/*
3732 	 * don't let napi dequeue from the cpu poll list
3733 	 * just in case its running on a different cpu
3734 	 */
3735 	if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
3736 		return;
3737 
3738 	napi_gro_flush(n);
3739 	local_irq_save(flags);
3740 	__napi_complete(n);
3741 	local_irq_restore(flags);
3742 }
3743 EXPORT_SYMBOL(napi_complete);
3744 
3745 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
3746 		    int (*poll)(struct napi_struct *, int), int weight)
3747 {
3748 	INIT_LIST_HEAD(&napi->poll_list);
3749 	napi->gro_count = 0;
3750 	napi->gro_list = NULL;
3751 	napi->skb = NULL;
3752 	napi->poll = poll;
3753 	napi->weight = weight;
3754 	list_add(&napi->dev_list, &dev->napi_list);
3755 	napi->dev = dev;
3756 #ifdef CONFIG_NETPOLL
3757 	spin_lock_init(&napi->poll_lock);
3758 	napi->poll_owner = -1;
3759 #endif
3760 	set_bit(NAPI_STATE_SCHED, &napi->state);
3761 }
3762 EXPORT_SYMBOL(netif_napi_add);
3763 
3764 void netif_napi_del(struct napi_struct *napi)
3765 {
3766 	struct sk_buff *skb, *next;
3767 
3768 	list_del_init(&napi->dev_list);
3769 	napi_free_frags(napi);
3770 
3771 	for (skb = napi->gro_list; skb; skb = next) {
3772 		next = skb->next;
3773 		skb->next = NULL;
3774 		kfree_skb(skb);
3775 	}
3776 
3777 	napi->gro_list = NULL;
3778 	napi->gro_count = 0;
3779 }
3780 EXPORT_SYMBOL(netif_napi_del);
3781 
3782 static void net_rx_action(struct softirq_action *h)
3783 {
3784 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3785 	unsigned long time_limit = jiffies + 2;
3786 	int budget = netdev_budget;
3787 	void *have;
3788 
3789 	local_irq_disable();
3790 
3791 	while (!list_empty(&sd->poll_list)) {
3792 		struct napi_struct *n;
3793 		int work, weight;
3794 
3795 		/* If softirq window is exhuasted then punt.
3796 		 * Allow this to run for 2 jiffies since which will allow
3797 		 * an average latency of 1.5/HZ.
3798 		 */
3799 		if (unlikely(budget <= 0 || time_after(jiffies, time_limit)))
3800 			goto softnet_break;
3801 
3802 		local_irq_enable();
3803 
3804 		/* Even though interrupts have been re-enabled, this
3805 		 * access is safe because interrupts can only add new
3806 		 * entries to the tail of this list, and only ->poll()
3807 		 * calls can remove this head entry from the list.
3808 		 */
3809 		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
3810 
3811 		have = netpoll_poll_lock(n);
3812 
3813 		weight = n->weight;
3814 
3815 		/* This NAPI_STATE_SCHED test is for avoiding a race
3816 		 * with netpoll's poll_napi().  Only the entity which
3817 		 * obtains the lock and sees NAPI_STATE_SCHED set will
3818 		 * actually make the ->poll() call.  Therefore we avoid
3819 		 * accidentally calling ->poll() when NAPI is not scheduled.
3820 		 */
3821 		work = 0;
3822 		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
3823 			work = n->poll(n, weight);
3824 			trace_napi_poll(n);
3825 		}
3826 
3827 		WARN_ON_ONCE(work > weight);
3828 
3829 		budget -= work;
3830 
3831 		local_irq_disable();
3832 
3833 		/* Drivers must not modify the NAPI state if they
3834 		 * consume the entire weight.  In such cases this code
3835 		 * still "owns" the NAPI instance and therefore can
3836 		 * move the instance around on the list at-will.
3837 		 */
3838 		if (unlikely(work == weight)) {
3839 			if (unlikely(napi_disable_pending(n))) {
3840 				local_irq_enable();
3841 				napi_complete(n);
3842 				local_irq_disable();
3843 			} else
3844 				list_move_tail(&n->poll_list, &sd->poll_list);
3845 		}
3846 
3847 		netpoll_poll_unlock(have);
3848 	}
3849 out:
3850 	net_rps_action_and_irq_enable(sd);
3851 
3852 #ifdef CONFIG_NET_DMA
3853 	/*
3854 	 * There may not be any more sk_buffs coming right now, so push
3855 	 * any pending DMA copies to hardware
3856 	 */
3857 	dma_issue_pending_all();
3858 #endif
3859 
3860 	return;
3861 
3862 softnet_break:
3863 	sd->time_squeeze++;
3864 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
3865 	goto out;
3866 }
3867 
3868 static gifconf_func_t *gifconf_list[NPROTO];
3869 
3870 /**
3871  *	register_gifconf	-	register a SIOCGIF handler
3872  *	@family: Address family
3873  *	@gifconf: Function handler
3874  *
3875  *	Register protocol dependent address dumping routines. The handler
3876  *	that is passed must not be freed or reused until it has been replaced
3877  *	by another handler.
3878  */
3879 int register_gifconf(unsigned int family, gifconf_func_t *gifconf)
3880 {
3881 	if (family >= NPROTO)
3882 		return -EINVAL;
3883 	gifconf_list[family] = gifconf;
3884 	return 0;
3885 }
3886 EXPORT_SYMBOL(register_gifconf);
3887 
3888 
3889 /*
3890  *	Map an interface index to its name (SIOCGIFNAME)
3891  */
3892 
3893 /*
3894  *	We need this ioctl for efficient implementation of the
3895  *	if_indextoname() function required by the IPv6 API.  Without
3896  *	it, we would have to search all the interfaces to find a
3897  *	match.  --pb
3898  */
3899 
3900 static int dev_ifname(struct net *net, struct ifreq __user *arg)
3901 {
3902 	struct net_device *dev;
3903 	struct ifreq ifr;
3904 
3905 	/*
3906 	 *	Fetch the caller's info block.
3907 	 */
3908 
3909 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
3910 		return -EFAULT;
3911 
3912 	rcu_read_lock();
3913 	dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex);
3914 	if (!dev) {
3915 		rcu_read_unlock();
3916 		return -ENODEV;
3917 	}
3918 
3919 	strcpy(ifr.ifr_name, dev->name);
3920 	rcu_read_unlock();
3921 
3922 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
3923 		return -EFAULT;
3924 	return 0;
3925 }
3926 
3927 /*
3928  *	Perform a SIOCGIFCONF call. This structure will change
3929  *	size eventually, and there is nothing I can do about it.
3930  *	Thus we will need a 'compatibility mode'.
3931  */
3932 
3933 static int dev_ifconf(struct net *net, char __user *arg)
3934 {
3935 	struct ifconf ifc;
3936 	struct net_device *dev;
3937 	char __user *pos;
3938 	int len;
3939 	int total;
3940 	int i;
3941 
3942 	/*
3943 	 *	Fetch the caller's info block.
3944 	 */
3945 
3946 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
3947 		return -EFAULT;
3948 
3949 	pos = ifc.ifc_buf;
3950 	len = ifc.ifc_len;
3951 
3952 	/*
3953 	 *	Loop over the interfaces, and write an info block for each.
3954 	 */
3955 
3956 	total = 0;
3957 	for_each_netdev(net, dev) {
3958 		for (i = 0; i < NPROTO; i++) {
3959 			if (gifconf_list[i]) {
3960 				int done;
3961 				if (!pos)
3962 					done = gifconf_list[i](dev, NULL, 0);
3963 				else
3964 					done = gifconf_list[i](dev, pos + total,
3965 							       len - total);
3966 				if (done < 0)
3967 					return -EFAULT;
3968 				total += done;
3969 			}
3970 		}
3971 	}
3972 
3973 	/*
3974 	 *	All done.  Write the updated control block back to the caller.
3975 	 */
3976 	ifc.ifc_len = total;
3977 
3978 	/*
3979 	 * 	Both BSD and Solaris return 0 here, so we do too.
3980 	 */
3981 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
3982 }
3983 
3984 #ifdef CONFIG_PROC_FS
3985 /*
3986  *	This is invoked by the /proc filesystem handler to display a device
3987  *	in detail.
3988  */
3989 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
3990 	__acquires(RCU)
3991 {
3992 	struct net *net = seq_file_net(seq);
3993 	loff_t off;
3994 	struct net_device *dev;
3995 
3996 	rcu_read_lock();
3997 	if (!*pos)
3998 		return SEQ_START_TOKEN;
3999 
4000 	off = 1;
4001 	for_each_netdev_rcu(net, dev)
4002 		if (off++ == *pos)
4003 			return dev;
4004 
4005 	return NULL;
4006 }
4007 
4008 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4009 {
4010 	struct net_device *dev = v;
4011 
4012 	if (v == SEQ_START_TOKEN)
4013 		dev = first_net_device_rcu(seq_file_net(seq));
4014 	else
4015 		dev = next_net_device_rcu(dev);
4016 
4017 	++*pos;
4018 	return dev;
4019 }
4020 
4021 void dev_seq_stop(struct seq_file *seq, void *v)
4022 	__releases(RCU)
4023 {
4024 	rcu_read_unlock();
4025 }
4026 
4027 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
4028 {
4029 	struct rtnl_link_stats64 temp;
4030 	const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);
4031 
4032 	seq_printf(seq, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu "
4033 		   "%8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu\n",
4034 		   dev->name, stats->rx_bytes, stats->rx_packets,
4035 		   stats->rx_errors,
4036 		   stats->rx_dropped + stats->rx_missed_errors,
4037 		   stats->rx_fifo_errors,
4038 		   stats->rx_length_errors + stats->rx_over_errors +
4039 		    stats->rx_crc_errors + stats->rx_frame_errors,
4040 		   stats->rx_compressed, stats->multicast,
4041 		   stats->tx_bytes, stats->tx_packets,
4042 		   stats->tx_errors, stats->tx_dropped,
4043 		   stats->tx_fifo_errors, stats->collisions,
4044 		   stats->tx_carrier_errors +
4045 		    stats->tx_aborted_errors +
4046 		    stats->tx_window_errors +
4047 		    stats->tx_heartbeat_errors,
4048 		   stats->tx_compressed);
4049 }
4050 
4051 /*
4052  *	Called from the PROCfs module. This now uses the new arbitrary sized
4053  *	/proc/net interface to create /proc/net/dev
4054  */
4055 static int dev_seq_show(struct seq_file *seq, void *v)
4056 {
4057 	if (v == SEQ_START_TOKEN)
4058 		seq_puts(seq, "Inter-|   Receive                            "
4059 			      "                    |  Transmit\n"
4060 			      " face |bytes    packets errs drop fifo frame "
4061 			      "compressed multicast|bytes    packets errs "
4062 			      "drop fifo colls carrier compressed\n");
4063 	else
4064 		dev_seq_printf_stats(seq, v);
4065 	return 0;
4066 }
4067 
4068 static struct softnet_data *softnet_get_online(loff_t *pos)
4069 {
4070 	struct softnet_data *sd = NULL;
4071 
4072 	while (*pos < nr_cpu_ids)
4073 		if (cpu_online(*pos)) {
4074 			sd = &per_cpu(softnet_data, *pos);
4075 			break;
4076 		} else
4077 			++*pos;
4078 	return sd;
4079 }
4080 
4081 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
4082 {
4083 	return softnet_get_online(pos);
4084 }
4085 
4086 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4087 {
4088 	++*pos;
4089 	return softnet_get_online(pos);
4090 }
4091 
4092 static void softnet_seq_stop(struct seq_file *seq, void *v)
4093 {
4094 }
4095 
4096 static int softnet_seq_show(struct seq_file *seq, void *v)
4097 {
4098 	struct softnet_data *sd = v;
4099 
4100 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
4101 		   sd->processed, sd->dropped, sd->time_squeeze, 0,
4102 		   0, 0, 0, 0, /* was fastroute */
4103 		   sd->cpu_collision, sd->received_rps);
4104 	return 0;
4105 }
4106 
4107 static const struct seq_operations dev_seq_ops = {
4108 	.start = dev_seq_start,
4109 	.next  = dev_seq_next,
4110 	.stop  = dev_seq_stop,
4111 	.show  = dev_seq_show,
4112 };
4113 
4114 static int dev_seq_open(struct inode *inode, struct file *file)
4115 {
4116 	return seq_open_net(inode, file, &dev_seq_ops,
4117 			    sizeof(struct seq_net_private));
4118 }
4119 
4120 static const struct file_operations dev_seq_fops = {
4121 	.owner	 = THIS_MODULE,
4122 	.open    = dev_seq_open,
4123 	.read    = seq_read,
4124 	.llseek  = seq_lseek,
4125 	.release = seq_release_net,
4126 };
4127 
4128 static const struct seq_operations softnet_seq_ops = {
4129 	.start = softnet_seq_start,
4130 	.next  = softnet_seq_next,
4131 	.stop  = softnet_seq_stop,
4132 	.show  = softnet_seq_show,
4133 };
4134 
4135 static int softnet_seq_open(struct inode *inode, struct file *file)
4136 {
4137 	return seq_open(file, &softnet_seq_ops);
4138 }
4139 
4140 static const struct file_operations softnet_seq_fops = {
4141 	.owner	 = THIS_MODULE,
4142 	.open    = softnet_seq_open,
4143 	.read    = seq_read,
4144 	.llseek  = seq_lseek,
4145 	.release = seq_release,
4146 };
4147 
4148 static void *ptype_get_idx(loff_t pos)
4149 {
4150 	struct packet_type *pt = NULL;
4151 	loff_t i = 0;
4152 	int t;
4153 
4154 	list_for_each_entry_rcu(pt, &ptype_all, list) {
4155 		if (i == pos)
4156 			return pt;
4157 		++i;
4158 	}
4159 
4160 	for (t = 0; t < PTYPE_HASH_SIZE; t++) {
4161 		list_for_each_entry_rcu(pt, &ptype_base[t], list) {
4162 			if (i == pos)
4163 				return pt;
4164 			++i;
4165 		}
4166 	}
4167 	return NULL;
4168 }
4169 
4170 static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
4171 	__acquires(RCU)
4172 {
4173 	rcu_read_lock();
4174 	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
4175 }
4176 
4177 static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4178 {
4179 	struct packet_type *pt;
4180 	struct list_head *nxt;
4181 	int hash;
4182 
4183 	++*pos;
4184 	if (v == SEQ_START_TOKEN)
4185 		return ptype_get_idx(0);
4186 
4187 	pt = v;
4188 	nxt = pt->list.next;
4189 	if (pt->type == htons(ETH_P_ALL)) {
4190 		if (nxt != &ptype_all)
4191 			goto found;
4192 		hash = 0;
4193 		nxt = ptype_base[0].next;
4194 	} else
4195 		hash = ntohs(pt->type) & PTYPE_HASH_MASK;
4196 
4197 	while (nxt == &ptype_base[hash]) {
4198 		if (++hash >= PTYPE_HASH_SIZE)
4199 			return NULL;
4200 		nxt = ptype_base[hash].next;
4201 	}
4202 found:
4203 	return list_entry(nxt, struct packet_type, list);
4204 }
4205 
4206 static void ptype_seq_stop(struct seq_file *seq, void *v)
4207 	__releases(RCU)
4208 {
4209 	rcu_read_unlock();
4210 }
4211 
4212 static int ptype_seq_show(struct seq_file *seq, void *v)
4213 {
4214 	struct packet_type *pt = v;
4215 
4216 	if (v == SEQ_START_TOKEN)
4217 		seq_puts(seq, "Type Device      Function\n");
4218 	else if (pt->dev == NULL || dev_net(pt->dev) == seq_file_net(seq)) {
4219 		if (pt->type == htons(ETH_P_ALL))
4220 			seq_puts(seq, "ALL ");
4221 		else
4222 			seq_printf(seq, "%04x", ntohs(pt->type));
4223 
4224 		seq_printf(seq, " %-8s %pF\n",
4225 			   pt->dev ? pt->dev->name : "", pt->func);
4226 	}
4227 
4228 	return 0;
4229 }
4230 
4231 static const struct seq_operations ptype_seq_ops = {
4232 	.start = ptype_seq_start,
4233 	.next  = ptype_seq_next,
4234 	.stop  = ptype_seq_stop,
4235 	.show  = ptype_seq_show,
4236 };
4237 
4238 static int ptype_seq_open(struct inode *inode, struct file *file)
4239 {
4240 	return seq_open_net(inode, file, &ptype_seq_ops,
4241 			sizeof(struct seq_net_private));
4242 }
4243 
4244 static const struct file_operations ptype_seq_fops = {
4245 	.owner	 = THIS_MODULE,
4246 	.open    = ptype_seq_open,
4247 	.read    = seq_read,
4248 	.llseek  = seq_lseek,
4249 	.release = seq_release_net,
4250 };
4251 
4252 
4253 static int __net_init dev_proc_net_init(struct net *net)
4254 {
4255 	int rc = -ENOMEM;
4256 
4257 	if (!proc_net_fops_create(net, "dev", S_IRUGO, &dev_seq_fops))
4258 		goto out;
4259 	if (!proc_net_fops_create(net, "softnet_stat", S_IRUGO, &softnet_seq_fops))
4260 		goto out_dev;
4261 	if (!proc_net_fops_create(net, "ptype", S_IRUGO, &ptype_seq_fops))
4262 		goto out_softnet;
4263 
4264 	if (wext_proc_init(net))
4265 		goto out_ptype;
4266 	rc = 0;
4267 out:
4268 	return rc;
4269 out_ptype:
4270 	proc_net_remove(net, "ptype");
4271 out_softnet:
4272 	proc_net_remove(net, "softnet_stat");
4273 out_dev:
4274 	proc_net_remove(net, "dev");
4275 	goto out;
4276 }
4277 
4278 static void __net_exit dev_proc_net_exit(struct net *net)
4279 {
4280 	wext_proc_exit(net);
4281 
4282 	proc_net_remove(net, "ptype");
4283 	proc_net_remove(net, "softnet_stat");
4284 	proc_net_remove(net, "dev");
4285 }
4286 
4287 static struct pernet_operations __net_initdata dev_proc_ops = {
4288 	.init = dev_proc_net_init,
4289 	.exit = dev_proc_net_exit,
4290 };
4291 
4292 static int __init dev_proc_init(void)
4293 {
4294 	return register_pernet_subsys(&dev_proc_ops);
4295 }
4296 #else
4297 #define dev_proc_init() 0
4298 #endif	/* CONFIG_PROC_FS */
4299 
4300 
4301 /**
4302  *	netdev_set_master	-	set up master pointer
4303  *	@slave: slave device
4304  *	@master: new master device
4305  *
4306  *	Changes the master device of the slave. Pass %NULL to break the
4307  *	bonding. The caller must hold the RTNL semaphore. On a failure
4308  *	a negative errno code is returned. On success the reference counts
4309  *	are adjusted and the function returns zero.
4310  */
4311 int netdev_set_master(struct net_device *slave, struct net_device *master)
4312 {
4313 	struct net_device *old = slave->master;
4314 
4315 	ASSERT_RTNL();
4316 
4317 	if (master) {
4318 		if (old)
4319 			return -EBUSY;
4320 		dev_hold(master);
4321 	}
4322 
4323 	slave->master = master;
4324 
4325 	if (old)
4326 		dev_put(old);
4327 	return 0;
4328 }
4329 EXPORT_SYMBOL(netdev_set_master);
4330 
4331 /**
4332  *	netdev_set_bond_master	-	set up bonding master/slave pair
4333  *	@slave: slave device
4334  *	@master: new master device
4335  *
4336  *	Changes the master device of the slave. Pass %NULL to break the
4337  *	bonding. The caller must hold the RTNL semaphore. On a failure
4338  *	a negative errno code is returned. On success %RTM_NEWLINK is sent
4339  *	to the routing socket and the function returns zero.
4340  */
4341 int netdev_set_bond_master(struct net_device *slave, struct net_device *master)
4342 {
4343 	int err;
4344 
4345 	ASSERT_RTNL();
4346 
4347 	err = netdev_set_master(slave, master);
4348 	if (err)
4349 		return err;
4350 	if (master)
4351 		slave->flags |= IFF_SLAVE;
4352 	else
4353 		slave->flags &= ~IFF_SLAVE;
4354 
4355 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
4356 	return 0;
4357 }
4358 EXPORT_SYMBOL(netdev_set_bond_master);
4359 
4360 static void dev_change_rx_flags(struct net_device *dev, int flags)
4361 {
4362 	const struct net_device_ops *ops = dev->netdev_ops;
4363 
4364 	if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
4365 		ops->ndo_change_rx_flags(dev, flags);
4366 }
4367 
4368 static int __dev_set_promiscuity(struct net_device *dev, int inc)
4369 {
4370 	unsigned short old_flags = dev->flags;
4371 	uid_t uid;
4372 	gid_t gid;
4373 
4374 	ASSERT_RTNL();
4375 
4376 	dev->flags |= IFF_PROMISC;
4377 	dev->promiscuity += inc;
4378 	if (dev->promiscuity == 0) {
4379 		/*
4380 		 * Avoid overflow.
4381 		 * If inc causes overflow, untouch promisc and return error.
4382 		 */
4383 		if (inc < 0)
4384 			dev->flags &= ~IFF_PROMISC;
4385 		else {
4386 			dev->promiscuity -= inc;
4387 			printk(KERN_WARNING "%s: promiscuity touches roof, "
4388 				"set promiscuity failed, promiscuity feature "
4389 				"of device might be broken.\n", dev->name);
4390 			return -EOVERFLOW;
4391 		}
4392 	}
4393 	if (dev->flags != old_flags) {
4394 		printk(KERN_INFO "device %s %s promiscuous mode\n",
4395 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
4396 							       "left");
4397 		if (audit_enabled) {
4398 			current_uid_gid(&uid, &gid);
4399 			audit_log(current->audit_context, GFP_ATOMIC,
4400 				AUDIT_ANOM_PROMISCUOUS,
4401 				"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
4402 				dev->name, (dev->flags & IFF_PROMISC),
4403 				(old_flags & IFF_PROMISC),
4404 				audit_get_loginuid(current),
4405 				uid, gid,
4406 				audit_get_sessionid(current));
4407 		}
4408 
4409 		dev_change_rx_flags(dev, IFF_PROMISC);
4410 	}
4411 	return 0;
4412 }
4413 
4414 /**
4415  *	dev_set_promiscuity	- update promiscuity count on a device
4416  *	@dev: device
4417  *	@inc: modifier
4418  *
4419  *	Add or remove promiscuity from a device. While the count in the device
4420  *	remains above zero the interface remains promiscuous. Once it hits zero
4421  *	the device reverts back to normal filtering operation. A negative inc
4422  *	value is used to drop promiscuity on the device.
4423  *	Return 0 if successful or a negative errno code on error.
4424  */
4425 int dev_set_promiscuity(struct net_device *dev, int inc)
4426 {
4427 	unsigned short old_flags = dev->flags;
4428 	int err;
4429 
4430 	err = __dev_set_promiscuity(dev, inc);
4431 	if (err < 0)
4432 		return err;
4433 	if (dev->flags != old_flags)
4434 		dev_set_rx_mode(dev);
4435 	return err;
4436 }
4437 EXPORT_SYMBOL(dev_set_promiscuity);
4438 
4439 /**
4440  *	dev_set_allmulti	- update allmulti count on a device
4441  *	@dev: device
4442  *	@inc: modifier
4443  *
4444  *	Add or remove reception of all multicast frames to a device. While the
4445  *	count in the device remains above zero the interface remains listening
4446  *	to all interfaces. Once it hits zero the device reverts back to normal
4447  *	filtering operation. A negative @inc value is used to drop the counter
4448  *	when releasing a resource needing all multicasts.
4449  *	Return 0 if successful or a negative errno code on error.
4450  */
4451 
4452 int dev_set_allmulti(struct net_device *dev, int inc)
4453 {
4454 	unsigned short old_flags = dev->flags;
4455 
4456 	ASSERT_RTNL();
4457 
4458 	dev->flags |= IFF_ALLMULTI;
4459 	dev->allmulti += inc;
4460 	if (dev->allmulti == 0) {
4461 		/*
4462 		 * Avoid overflow.
4463 		 * If inc causes overflow, untouch allmulti and return error.
4464 		 */
4465 		if (inc < 0)
4466 			dev->flags &= ~IFF_ALLMULTI;
4467 		else {
4468 			dev->allmulti -= inc;
4469 			printk(KERN_WARNING "%s: allmulti touches roof, "
4470 				"set allmulti failed, allmulti feature of "
4471 				"device might be broken.\n", dev->name);
4472 			return -EOVERFLOW;
4473 		}
4474 	}
4475 	if (dev->flags ^ old_flags) {
4476 		dev_change_rx_flags(dev, IFF_ALLMULTI);
4477 		dev_set_rx_mode(dev);
4478 	}
4479 	return 0;
4480 }
4481 EXPORT_SYMBOL(dev_set_allmulti);
4482 
4483 /*
4484  *	Upload unicast and multicast address lists to device and
4485  *	configure RX filtering. When the device doesn't support unicast
4486  *	filtering it is put in promiscuous mode while unicast addresses
4487  *	are present.
4488  */
4489 void __dev_set_rx_mode(struct net_device *dev)
4490 {
4491 	const struct net_device_ops *ops = dev->netdev_ops;
4492 
4493 	/* dev_open will call this function so the list will stay sane. */
4494 	if (!(dev->flags&IFF_UP))
4495 		return;
4496 
4497 	if (!netif_device_present(dev))
4498 		return;
4499 
4500 	if (ops->ndo_set_rx_mode)
4501 		ops->ndo_set_rx_mode(dev);
4502 	else {
4503 		/* Unicast addresses changes may only happen under the rtnl,
4504 		 * therefore calling __dev_set_promiscuity here is safe.
4505 		 */
4506 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4507 			__dev_set_promiscuity(dev, 1);
4508 			dev->uc_promisc = true;
4509 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4510 			__dev_set_promiscuity(dev, -1);
4511 			dev->uc_promisc = false;
4512 		}
4513 
4514 		if (ops->ndo_set_multicast_list)
4515 			ops->ndo_set_multicast_list(dev);
4516 	}
4517 }
4518 
4519 void dev_set_rx_mode(struct net_device *dev)
4520 {
4521 	netif_addr_lock_bh(dev);
4522 	__dev_set_rx_mode(dev);
4523 	netif_addr_unlock_bh(dev);
4524 }
4525 
4526 /**
4527  *	dev_ethtool_get_settings - call device's ethtool_ops::get_settings()
4528  *	@dev: device
4529  *	@cmd: memory area for ethtool_ops::get_settings() result
4530  *
4531  *      The cmd arg is initialized properly (cleared and
4532  *      ethtool_cmd::cmd field set to ETHTOOL_GSET).
4533  *
4534  *	Return device's ethtool_ops::get_settings() result value or
4535  *	-EOPNOTSUPP when device doesn't expose
4536  *	ethtool_ops::get_settings() operation.
4537  */
4538 int dev_ethtool_get_settings(struct net_device *dev,
4539 			     struct ethtool_cmd *cmd)
4540 {
4541 	if (!dev->ethtool_ops || !dev->ethtool_ops->get_settings)
4542 		return -EOPNOTSUPP;
4543 
4544 	memset(cmd, 0, sizeof(struct ethtool_cmd));
4545 	cmd->cmd = ETHTOOL_GSET;
4546 	return dev->ethtool_ops->get_settings(dev, cmd);
4547 }
4548 EXPORT_SYMBOL(dev_ethtool_get_settings);
4549 
4550 /**
4551  *	dev_get_flags - get flags reported to userspace
4552  *	@dev: device
4553  *
4554  *	Get the combination of flag bits exported through APIs to userspace.
4555  */
4556 unsigned dev_get_flags(const struct net_device *dev)
4557 {
4558 	unsigned flags;
4559 
4560 	flags = (dev->flags & ~(IFF_PROMISC |
4561 				IFF_ALLMULTI |
4562 				IFF_RUNNING |
4563 				IFF_LOWER_UP |
4564 				IFF_DORMANT)) |
4565 		(dev->gflags & (IFF_PROMISC |
4566 				IFF_ALLMULTI));
4567 
4568 	if (netif_running(dev)) {
4569 		if (netif_oper_up(dev))
4570 			flags |= IFF_RUNNING;
4571 		if (netif_carrier_ok(dev))
4572 			flags |= IFF_LOWER_UP;
4573 		if (netif_dormant(dev))
4574 			flags |= IFF_DORMANT;
4575 	}
4576 
4577 	return flags;
4578 }
4579 EXPORT_SYMBOL(dev_get_flags);
4580 
4581 int __dev_change_flags(struct net_device *dev, unsigned int flags)
4582 {
4583 	int old_flags = dev->flags;
4584 	int ret;
4585 
4586 	ASSERT_RTNL();
4587 
4588 	/*
4589 	 *	Set the flags on our device.
4590 	 */
4591 
4592 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
4593 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
4594 			       IFF_AUTOMEDIA)) |
4595 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
4596 				    IFF_ALLMULTI));
4597 
4598 	/*
4599 	 *	Load in the correct multicast list now the flags have changed.
4600 	 */
4601 
4602 	if ((old_flags ^ flags) & IFF_MULTICAST)
4603 		dev_change_rx_flags(dev, IFF_MULTICAST);
4604 
4605 	dev_set_rx_mode(dev);
4606 
4607 	/*
4608 	 *	Have we downed the interface. We handle IFF_UP ourselves
4609 	 *	according to user attempts to set it, rather than blindly
4610 	 *	setting it.
4611 	 */
4612 
4613 	ret = 0;
4614 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
4615 		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
4616 
4617 		if (!ret)
4618 			dev_set_rx_mode(dev);
4619 	}
4620 
4621 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
4622 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
4623 
4624 		dev->gflags ^= IFF_PROMISC;
4625 		dev_set_promiscuity(dev, inc);
4626 	}
4627 
4628 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
4629 	   is important. Some (broken) drivers set IFF_PROMISC, when
4630 	   IFF_ALLMULTI is requested not asking us and not reporting.
4631 	 */
4632 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
4633 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
4634 
4635 		dev->gflags ^= IFF_ALLMULTI;
4636 		dev_set_allmulti(dev, inc);
4637 	}
4638 
4639 	return ret;
4640 }
4641 
4642 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
4643 {
4644 	unsigned int changes = dev->flags ^ old_flags;
4645 
4646 	if (changes & IFF_UP) {
4647 		if (dev->flags & IFF_UP)
4648 			call_netdevice_notifiers(NETDEV_UP, dev);
4649 		else
4650 			call_netdevice_notifiers(NETDEV_DOWN, dev);
4651 	}
4652 
4653 	if (dev->flags & IFF_UP &&
4654 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE)))
4655 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
4656 }
4657 
4658 /**
4659  *	dev_change_flags - change device settings
4660  *	@dev: device
4661  *	@flags: device state flags
4662  *
4663  *	Change settings on device based state flags. The flags are
4664  *	in the userspace exported format.
4665  */
4666 int dev_change_flags(struct net_device *dev, unsigned flags)
4667 {
4668 	int ret, changes;
4669 	int old_flags = dev->flags;
4670 
4671 	ret = __dev_change_flags(dev, flags);
4672 	if (ret < 0)
4673 		return ret;
4674 
4675 	changes = old_flags ^ dev->flags;
4676 	if (changes)
4677 		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
4678 
4679 	__dev_notify_flags(dev, old_flags);
4680 	return ret;
4681 }
4682 EXPORT_SYMBOL(dev_change_flags);
4683 
4684 /**
4685  *	dev_set_mtu - Change maximum transfer unit
4686  *	@dev: device
4687  *	@new_mtu: new transfer unit
4688  *
4689  *	Change the maximum transfer size of the network device.
4690  */
4691 int dev_set_mtu(struct net_device *dev, int new_mtu)
4692 {
4693 	const struct net_device_ops *ops = dev->netdev_ops;
4694 	int err;
4695 
4696 	if (new_mtu == dev->mtu)
4697 		return 0;
4698 
4699 	/*	MTU must be positive.	 */
4700 	if (new_mtu < 0)
4701 		return -EINVAL;
4702 
4703 	if (!netif_device_present(dev))
4704 		return -ENODEV;
4705 
4706 	err = 0;
4707 	if (ops->ndo_change_mtu)
4708 		err = ops->ndo_change_mtu(dev, new_mtu);
4709 	else
4710 		dev->mtu = new_mtu;
4711 
4712 	if (!err && dev->flags & IFF_UP)
4713 		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
4714 	return err;
4715 }
4716 EXPORT_SYMBOL(dev_set_mtu);
4717 
4718 /**
4719  *	dev_set_group - Change group this device belongs to
4720  *	@dev: device
4721  *	@new_group: group this device should belong to
4722  */
4723 void dev_set_group(struct net_device *dev, int new_group)
4724 {
4725 	dev->group = new_group;
4726 }
4727 EXPORT_SYMBOL(dev_set_group);
4728 
4729 /**
4730  *	dev_set_mac_address - Change Media Access Control Address
4731  *	@dev: device
4732  *	@sa: new address
4733  *
4734  *	Change the hardware (MAC) address of the device
4735  */
4736 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
4737 {
4738 	const struct net_device_ops *ops = dev->netdev_ops;
4739 	int err;
4740 
4741 	if (!ops->ndo_set_mac_address)
4742 		return -EOPNOTSUPP;
4743 	if (sa->sa_family != dev->type)
4744 		return -EINVAL;
4745 	if (!netif_device_present(dev))
4746 		return -ENODEV;
4747 	err = ops->ndo_set_mac_address(dev, sa);
4748 	if (!err)
4749 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4750 	return err;
4751 }
4752 EXPORT_SYMBOL(dev_set_mac_address);
4753 
4754 /*
4755  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
4756  */
4757 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
4758 {
4759 	int err;
4760 	struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
4761 
4762 	if (!dev)
4763 		return -ENODEV;
4764 
4765 	switch (cmd) {
4766 	case SIOCGIFFLAGS:	/* Get interface flags */
4767 		ifr->ifr_flags = (short) dev_get_flags(dev);
4768 		return 0;
4769 
4770 	case SIOCGIFMETRIC:	/* Get the metric on the interface
4771 				   (currently unused) */
4772 		ifr->ifr_metric = 0;
4773 		return 0;
4774 
4775 	case SIOCGIFMTU:	/* Get the MTU of a device */
4776 		ifr->ifr_mtu = dev->mtu;
4777 		return 0;
4778 
4779 	case SIOCGIFHWADDR:
4780 		if (!dev->addr_len)
4781 			memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
4782 		else
4783 			memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
4784 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4785 		ifr->ifr_hwaddr.sa_family = dev->type;
4786 		return 0;
4787 
4788 	case SIOCGIFSLAVE:
4789 		err = -EINVAL;
4790 		break;
4791 
4792 	case SIOCGIFMAP:
4793 		ifr->ifr_map.mem_start = dev->mem_start;
4794 		ifr->ifr_map.mem_end   = dev->mem_end;
4795 		ifr->ifr_map.base_addr = dev->base_addr;
4796 		ifr->ifr_map.irq       = dev->irq;
4797 		ifr->ifr_map.dma       = dev->dma;
4798 		ifr->ifr_map.port      = dev->if_port;
4799 		return 0;
4800 
4801 	case SIOCGIFINDEX:
4802 		ifr->ifr_ifindex = dev->ifindex;
4803 		return 0;
4804 
4805 	case SIOCGIFTXQLEN:
4806 		ifr->ifr_qlen = dev->tx_queue_len;
4807 		return 0;
4808 
4809 	default:
4810 		/* dev_ioctl() should ensure this case
4811 		 * is never reached
4812 		 */
4813 		WARN_ON(1);
4814 		err = -ENOTTY;
4815 		break;
4816 
4817 	}
4818 	return err;
4819 }
4820 
4821 /*
4822  *	Perform the SIOCxIFxxx calls, inside rtnl_lock()
4823  */
4824 static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
4825 {
4826 	int err;
4827 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
4828 	const struct net_device_ops *ops;
4829 
4830 	if (!dev)
4831 		return -ENODEV;
4832 
4833 	ops = dev->netdev_ops;
4834 
4835 	switch (cmd) {
4836 	case SIOCSIFFLAGS:	/* Set interface flags */
4837 		return dev_change_flags(dev, ifr->ifr_flags);
4838 
4839 	case SIOCSIFMETRIC:	/* Set the metric on the interface
4840 				   (currently unused) */
4841 		return -EOPNOTSUPP;
4842 
4843 	case SIOCSIFMTU:	/* Set the MTU of a device */
4844 		return dev_set_mtu(dev, ifr->ifr_mtu);
4845 
4846 	case SIOCSIFHWADDR:
4847 		return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
4848 
4849 	case SIOCSIFHWBROADCAST:
4850 		if (ifr->ifr_hwaddr.sa_family != dev->type)
4851 			return -EINVAL;
4852 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
4853 		       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4854 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4855 		return 0;
4856 
4857 	case SIOCSIFMAP:
4858 		if (ops->ndo_set_config) {
4859 			if (!netif_device_present(dev))
4860 				return -ENODEV;
4861 			return ops->ndo_set_config(dev, &ifr->ifr_map);
4862 		}
4863 		return -EOPNOTSUPP;
4864 
4865 	case SIOCADDMULTI:
4866 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4867 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4868 			return -EINVAL;
4869 		if (!netif_device_present(dev))
4870 			return -ENODEV;
4871 		return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
4872 
4873 	case SIOCDELMULTI:
4874 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4875 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4876 			return -EINVAL;
4877 		if (!netif_device_present(dev))
4878 			return -ENODEV;
4879 		return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
4880 
4881 	case SIOCSIFTXQLEN:
4882 		if (ifr->ifr_qlen < 0)
4883 			return -EINVAL;
4884 		dev->tx_queue_len = ifr->ifr_qlen;
4885 		return 0;
4886 
4887 	case SIOCSIFNAME:
4888 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
4889 		return dev_change_name(dev, ifr->ifr_newname);
4890 
4891 	/*
4892 	 *	Unknown or private ioctl
4893 	 */
4894 	default:
4895 		if ((cmd >= SIOCDEVPRIVATE &&
4896 		    cmd <= SIOCDEVPRIVATE + 15) ||
4897 		    cmd == SIOCBONDENSLAVE ||
4898 		    cmd == SIOCBONDRELEASE ||
4899 		    cmd == SIOCBONDSETHWADDR ||
4900 		    cmd == SIOCBONDSLAVEINFOQUERY ||
4901 		    cmd == SIOCBONDINFOQUERY ||
4902 		    cmd == SIOCBONDCHANGEACTIVE ||
4903 		    cmd == SIOCGMIIPHY ||
4904 		    cmd == SIOCGMIIREG ||
4905 		    cmd == SIOCSMIIREG ||
4906 		    cmd == SIOCBRADDIF ||
4907 		    cmd == SIOCBRDELIF ||
4908 		    cmd == SIOCSHWTSTAMP ||
4909 		    cmd == SIOCWANDEV) {
4910 			err = -EOPNOTSUPP;
4911 			if (ops->ndo_do_ioctl) {
4912 				if (netif_device_present(dev))
4913 					err = ops->ndo_do_ioctl(dev, ifr, cmd);
4914 				else
4915 					err = -ENODEV;
4916 			}
4917 		} else
4918 			err = -EINVAL;
4919 
4920 	}
4921 	return err;
4922 }
4923 
4924 /*
4925  *	This function handles all "interface"-type I/O control requests. The actual
4926  *	'doing' part of this is dev_ifsioc above.
4927  */
4928 
4929 /**
4930  *	dev_ioctl	-	network device ioctl
4931  *	@net: the applicable net namespace
4932  *	@cmd: command to issue
4933  *	@arg: pointer to a struct ifreq in user space
4934  *
4935  *	Issue ioctl functions to devices. This is normally called by the
4936  *	user space syscall interfaces but can sometimes be useful for
4937  *	other purposes. The return value is the return from the syscall if
4938  *	positive or a negative errno code on error.
4939  */
4940 
4941 int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
4942 {
4943 	struct ifreq ifr;
4944 	int ret;
4945 	char *colon;
4946 
4947 	/* One special case: SIOCGIFCONF takes ifconf argument
4948 	   and requires shared lock, because it sleeps writing
4949 	   to user space.
4950 	 */
4951 
4952 	if (cmd == SIOCGIFCONF) {
4953 		rtnl_lock();
4954 		ret = dev_ifconf(net, (char __user *) arg);
4955 		rtnl_unlock();
4956 		return ret;
4957 	}
4958 	if (cmd == SIOCGIFNAME)
4959 		return dev_ifname(net, (struct ifreq __user *)arg);
4960 
4961 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
4962 		return -EFAULT;
4963 
4964 	ifr.ifr_name[IFNAMSIZ-1] = 0;
4965 
4966 	colon = strchr(ifr.ifr_name, ':');
4967 	if (colon)
4968 		*colon = 0;
4969 
4970 	/*
4971 	 *	See which interface the caller is talking about.
4972 	 */
4973 
4974 	switch (cmd) {
4975 	/*
4976 	 *	These ioctl calls:
4977 	 *	- can be done by all.
4978 	 *	- atomic and do not require locking.
4979 	 *	- return a value
4980 	 */
4981 	case SIOCGIFFLAGS:
4982 	case SIOCGIFMETRIC:
4983 	case SIOCGIFMTU:
4984 	case SIOCGIFHWADDR:
4985 	case SIOCGIFSLAVE:
4986 	case SIOCGIFMAP:
4987 	case SIOCGIFINDEX:
4988 	case SIOCGIFTXQLEN:
4989 		dev_load(net, ifr.ifr_name);
4990 		rcu_read_lock();
4991 		ret = dev_ifsioc_locked(net, &ifr, cmd);
4992 		rcu_read_unlock();
4993 		if (!ret) {
4994 			if (colon)
4995 				*colon = ':';
4996 			if (copy_to_user(arg, &ifr,
4997 					 sizeof(struct ifreq)))
4998 				ret = -EFAULT;
4999 		}
5000 		return ret;
5001 
5002 	case SIOCETHTOOL:
5003 		dev_load(net, ifr.ifr_name);
5004 		rtnl_lock();
5005 		ret = dev_ethtool(net, &ifr);
5006 		rtnl_unlock();
5007 		if (!ret) {
5008 			if (colon)
5009 				*colon = ':';
5010 			if (copy_to_user(arg, &ifr,
5011 					 sizeof(struct ifreq)))
5012 				ret = -EFAULT;
5013 		}
5014 		return ret;
5015 
5016 	/*
5017 	 *	These ioctl calls:
5018 	 *	- require superuser power.
5019 	 *	- require strict serialization.
5020 	 *	- return a value
5021 	 */
5022 	case SIOCGMIIPHY:
5023 	case SIOCGMIIREG:
5024 	case SIOCSIFNAME:
5025 		if (!capable(CAP_NET_ADMIN))
5026 			return -EPERM;
5027 		dev_load(net, ifr.ifr_name);
5028 		rtnl_lock();
5029 		ret = dev_ifsioc(net, &ifr, cmd);
5030 		rtnl_unlock();
5031 		if (!ret) {
5032 			if (colon)
5033 				*colon = ':';
5034 			if (copy_to_user(arg, &ifr,
5035 					 sizeof(struct ifreq)))
5036 				ret = -EFAULT;
5037 		}
5038 		return ret;
5039 
5040 	/*
5041 	 *	These ioctl calls:
5042 	 *	- require superuser power.
5043 	 *	- require strict serialization.
5044 	 *	- do not return a value
5045 	 */
5046 	case SIOCSIFFLAGS:
5047 	case SIOCSIFMETRIC:
5048 	case SIOCSIFMTU:
5049 	case SIOCSIFMAP:
5050 	case SIOCSIFHWADDR:
5051 	case SIOCSIFSLAVE:
5052 	case SIOCADDMULTI:
5053 	case SIOCDELMULTI:
5054 	case SIOCSIFHWBROADCAST:
5055 	case SIOCSIFTXQLEN:
5056 	case SIOCSMIIREG:
5057 	case SIOCBONDENSLAVE:
5058 	case SIOCBONDRELEASE:
5059 	case SIOCBONDSETHWADDR:
5060 	case SIOCBONDCHANGEACTIVE:
5061 	case SIOCBRADDIF:
5062 	case SIOCBRDELIF:
5063 	case SIOCSHWTSTAMP:
5064 		if (!capable(CAP_NET_ADMIN))
5065 			return -EPERM;
5066 		/* fall through */
5067 	case SIOCBONDSLAVEINFOQUERY:
5068 	case SIOCBONDINFOQUERY:
5069 		dev_load(net, ifr.ifr_name);
5070 		rtnl_lock();
5071 		ret = dev_ifsioc(net, &ifr, cmd);
5072 		rtnl_unlock();
5073 		return ret;
5074 
5075 	case SIOCGIFMEM:
5076 		/* Get the per device memory space. We can add this but
5077 		 * currently do not support it */
5078 	case SIOCSIFMEM:
5079 		/* Set the per device memory buffer space.
5080 		 * Not applicable in our case */
5081 	case SIOCSIFLINK:
5082 		return -ENOTTY;
5083 
5084 	/*
5085 	 *	Unknown or private ioctl.
5086 	 */
5087 	default:
5088 		if (cmd == SIOCWANDEV ||
5089 		    (cmd >= SIOCDEVPRIVATE &&
5090 		     cmd <= SIOCDEVPRIVATE + 15)) {
5091 			dev_load(net, ifr.ifr_name);
5092 			rtnl_lock();
5093 			ret = dev_ifsioc(net, &ifr, cmd);
5094 			rtnl_unlock();
5095 			if (!ret && copy_to_user(arg, &ifr,
5096 						 sizeof(struct ifreq)))
5097 				ret = -EFAULT;
5098 			return ret;
5099 		}
5100 		/* Take care of Wireless Extensions */
5101 		if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
5102 			return wext_handle_ioctl(net, &ifr, cmd, arg);
5103 		return -ENOTTY;
5104 	}
5105 }
5106 
5107 
5108 /**
5109  *	dev_new_index	-	allocate an ifindex
5110  *	@net: the applicable net namespace
5111  *
5112  *	Returns a suitable unique value for a new device interface
5113  *	number.  The caller must hold the rtnl semaphore or the
5114  *	dev_base_lock to be sure it remains unique.
5115  */
5116 static int dev_new_index(struct net *net)
5117 {
5118 	static int ifindex;
5119 	for (;;) {
5120 		if (++ifindex <= 0)
5121 			ifindex = 1;
5122 		if (!__dev_get_by_index(net, ifindex))
5123 			return ifindex;
5124 	}
5125 }
5126 
5127 /* Delayed registration/unregisteration */
5128 static LIST_HEAD(net_todo_list);
5129 
5130 static void net_set_todo(struct net_device *dev)
5131 {
5132 	list_add_tail(&dev->todo_list, &net_todo_list);
5133 }
5134 
5135 static void rollback_registered_many(struct list_head *head)
5136 {
5137 	struct net_device *dev, *tmp;
5138 
5139 	BUG_ON(dev_boot_phase);
5140 	ASSERT_RTNL();
5141 
5142 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5143 		/* Some devices call without registering
5144 		 * for initialization unwind. Remove those
5145 		 * devices and proceed with the remaining.
5146 		 */
5147 		if (dev->reg_state == NETREG_UNINITIALIZED) {
5148 			pr_debug("unregister_netdevice: device %s/%p never "
5149 				 "was registered\n", dev->name, dev);
5150 
5151 			WARN_ON(1);
5152 			list_del(&dev->unreg_list);
5153 			continue;
5154 		}
5155 		dev->dismantle = true;
5156 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
5157 	}
5158 
5159 	/* If device is running, close it first. */
5160 	dev_close_many(head);
5161 
5162 	list_for_each_entry(dev, head, unreg_list) {
5163 		/* And unlink it from device chain. */
5164 		unlist_netdevice(dev);
5165 
5166 		dev->reg_state = NETREG_UNREGISTERING;
5167 	}
5168 
5169 	synchronize_net();
5170 
5171 	list_for_each_entry(dev, head, unreg_list) {
5172 		/* Shutdown queueing discipline. */
5173 		dev_shutdown(dev);
5174 
5175 
5176 		/* Notify protocols, that we are about to destroy
5177 		   this device. They should clean all the things.
5178 		*/
5179 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5180 
5181 		if (!dev->rtnl_link_ops ||
5182 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5183 			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
5184 
5185 		/*
5186 		 *	Flush the unicast and multicast chains
5187 		 */
5188 		dev_uc_flush(dev);
5189 		dev_mc_flush(dev);
5190 
5191 		if (dev->netdev_ops->ndo_uninit)
5192 			dev->netdev_ops->ndo_uninit(dev);
5193 
5194 		/* Notifier chain MUST detach us from master device. */
5195 		WARN_ON(dev->master);
5196 
5197 		/* Remove entries from kobject tree */
5198 		netdev_unregister_kobject(dev);
5199 	}
5200 
5201 	/* Process any work delayed until the end of the batch */
5202 	dev = list_first_entry(head, struct net_device, unreg_list);
5203 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
5204 
5205 	rcu_barrier();
5206 
5207 	list_for_each_entry(dev, head, unreg_list)
5208 		dev_put(dev);
5209 }
5210 
5211 static void rollback_registered(struct net_device *dev)
5212 {
5213 	LIST_HEAD(single);
5214 
5215 	list_add(&dev->unreg_list, &single);
5216 	rollback_registered_many(&single);
5217 	list_del(&single);
5218 }
5219 
5220 static u32 netdev_fix_features(struct net_device *dev, u32 features)
5221 {
5222 	/* Fix illegal checksum combinations */
5223 	if ((features & NETIF_F_HW_CSUM) &&
5224 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5225 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5226 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
5227 	}
5228 
5229 	if ((features & NETIF_F_NO_CSUM) &&
5230 	    (features & (NETIF_F_HW_CSUM|NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5231 		netdev_warn(dev, "mixed no checksumming and other settings.\n");
5232 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM|NETIF_F_HW_CSUM);
5233 	}
5234 
5235 	/* Fix illegal SG+CSUM combinations. */
5236 	if ((features & NETIF_F_SG) &&
5237 	    !(features & NETIF_F_ALL_CSUM)) {
5238 		netdev_dbg(dev,
5239 			"Dropping NETIF_F_SG since no checksum feature.\n");
5240 		features &= ~NETIF_F_SG;
5241 	}
5242 
5243 	/* TSO requires that SG is present as well. */
5244 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5245 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5246 		features &= ~NETIF_F_ALL_TSO;
5247 	}
5248 
5249 	/* TSO ECN requires that TSO is present as well. */
5250 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
5251 		features &= ~NETIF_F_TSO_ECN;
5252 
5253 	/* Software GSO depends on SG. */
5254 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5255 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5256 		features &= ~NETIF_F_GSO;
5257 	}
5258 
5259 	/* UFO needs SG and checksumming */
5260 	if (features & NETIF_F_UFO) {
5261 		/* maybe split UFO into V4 and V6? */
5262 		if (!((features & NETIF_F_GEN_CSUM) ||
5263 		    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
5264 			    == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5265 			netdev_dbg(dev,
5266 				"Dropping NETIF_F_UFO since no checksum offload features.\n");
5267 			features &= ~NETIF_F_UFO;
5268 		}
5269 
5270 		if (!(features & NETIF_F_SG)) {
5271 			netdev_dbg(dev,
5272 				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5273 			features &= ~NETIF_F_UFO;
5274 		}
5275 	}
5276 
5277 	return features;
5278 }
5279 
5280 int __netdev_update_features(struct net_device *dev)
5281 {
5282 	u32 features;
5283 	int err = 0;
5284 
5285 	ASSERT_RTNL();
5286 
5287 	features = netdev_get_wanted_features(dev);
5288 
5289 	if (dev->netdev_ops->ndo_fix_features)
5290 		features = dev->netdev_ops->ndo_fix_features(dev, features);
5291 
5292 	/* driver might be less strict about feature dependencies */
5293 	features = netdev_fix_features(dev, features);
5294 
5295 	if (dev->features == features)
5296 		return 0;
5297 
5298 	netdev_dbg(dev, "Features changed: 0x%08x -> 0x%08x\n",
5299 		dev->features, features);
5300 
5301 	if (dev->netdev_ops->ndo_set_features)
5302 		err = dev->netdev_ops->ndo_set_features(dev, features);
5303 
5304 	if (unlikely(err < 0)) {
5305 		netdev_err(dev,
5306 			"set_features() failed (%d); wanted 0x%08x, left 0x%08x\n",
5307 			err, features, dev->features);
5308 		return -1;
5309 	}
5310 
5311 	if (!err)
5312 		dev->features = features;
5313 
5314 	return 1;
5315 }
5316 
5317 /**
5318  *	netdev_update_features - recalculate device features
5319  *	@dev: the device to check
5320  *
5321  *	Recalculate dev->features set and send notifications if it
5322  *	has changed. Should be called after driver or hardware dependent
5323  *	conditions might have changed that influence the features.
5324  */
5325 void netdev_update_features(struct net_device *dev)
5326 {
5327 	if (__netdev_update_features(dev))
5328 		netdev_features_change(dev);
5329 }
5330 EXPORT_SYMBOL(netdev_update_features);
5331 
5332 /**
5333  *	netdev_change_features - recalculate device features
5334  *	@dev: the device to check
5335  *
5336  *	Recalculate dev->features set and send notifications even
5337  *	if they have not changed. Should be called instead of
5338  *	netdev_update_features() if also dev->vlan_features might
5339  *	have changed to allow the changes to be propagated to stacked
5340  *	VLAN devices.
5341  */
5342 void netdev_change_features(struct net_device *dev)
5343 {
5344 	__netdev_update_features(dev);
5345 	netdev_features_change(dev);
5346 }
5347 EXPORT_SYMBOL(netdev_change_features);
5348 
5349 /**
5350  *	netif_stacked_transfer_operstate -	transfer operstate
5351  *	@rootdev: the root or lower level device to transfer state from
5352  *	@dev: the device to transfer operstate to
5353  *
5354  *	Transfer operational state from root to device. This is normally
5355  *	called when a stacking relationship exists between the root
5356  *	device and the device(a leaf device).
5357  */
5358 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
5359 					struct net_device *dev)
5360 {
5361 	if (rootdev->operstate == IF_OPER_DORMANT)
5362 		netif_dormant_on(dev);
5363 	else
5364 		netif_dormant_off(dev);
5365 
5366 	if (netif_carrier_ok(rootdev)) {
5367 		if (!netif_carrier_ok(dev))
5368 			netif_carrier_on(dev);
5369 	} else {
5370 		if (netif_carrier_ok(dev))
5371 			netif_carrier_off(dev);
5372 	}
5373 }
5374 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
5375 
5376 #ifdef CONFIG_RPS
5377 static int netif_alloc_rx_queues(struct net_device *dev)
5378 {
5379 	unsigned int i, count = dev->num_rx_queues;
5380 	struct netdev_rx_queue *rx;
5381 
5382 	BUG_ON(count < 1);
5383 
5384 	rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5385 	if (!rx) {
5386 		pr_err("netdev: Unable to allocate %u rx queues.\n", count);
5387 		return -ENOMEM;
5388 	}
5389 	dev->_rx = rx;
5390 
5391 	for (i = 0; i < count; i++)
5392 		rx[i].dev = dev;
5393 	return 0;
5394 }
5395 #endif
5396 
5397 static void netdev_init_one_queue(struct net_device *dev,
5398 				  struct netdev_queue *queue, void *_unused)
5399 {
5400 	/* Initialize queue lock */
5401 	spin_lock_init(&queue->_xmit_lock);
5402 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
5403 	queue->xmit_lock_owner = -1;
5404 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
5405 	queue->dev = dev;
5406 }
5407 
5408 static int netif_alloc_netdev_queues(struct net_device *dev)
5409 {
5410 	unsigned int count = dev->num_tx_queues;
5411 	struct netdev_queue *tx;
5412 
5413 	BUG_ON(count < 1);
5414 
5415 	tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
5416 	if (!tx) {
5417 		pr_err("netdev: Unable to allocate %u tx queues.\n",
5418 		       count);
5419 		return -ENOMEM;
5420 	}
5421 	dev->_tx = tx;
5422 
5423 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5424 	spin_lock_init(&dev->tx_global_lock);
5425 
5426 	return 0;
5427 }
5428 
5429 /**
5430  *	register_netdevice	- register a network device
5431  *	@dev: device to register
5432  *
5433  *	Take a completed network device structure and add it to the kernel
5434  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5435  *	chain. 0 is returned on success. A negative errno code is returned
5436  *	on a failure to set up the device, or if the name is a duplicate.
5437  *
5438  *	Callers must hold the rtnl semaphore. You may want
5439  *	register_netdev() instead of this.
5440  *
5441  *	BUGS:
5442  *	The locking appears insufficient to guarantee two parallel registers
5443  *	will not get the same name.
5444  */
5445 
5446 int register_netdevice(struct net_device *dev)
5447 {
5448 	int ret;
5449 	struct net *net = dev_net(dev);
5450 
5451 	BUG_ON(dev_boot_phase);
5452 	ASSERT_RTNL();
5453 
5454 	might_sleep();
5455 
5456 	/* When net_device's are persistent, this will be fatal. */
5457 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5458 	BUG_ON(!net);
5459 
5460 	spin_lock_init(&dev->addr_list_lock);
5461 	netdev_set_addr_lockdep_class(dev);
5462 
5463 	dev->iflink = -1;
5464 
5465 	ret = dev_get_valid_name(dev, dev->name);
5466 	if (ret < 0)
5467 		goto out;
5468 
5469 	/* Init, if this function is available */
5470 	if (dev->netdev_ops->ndo_init) {
5471 		ret = dev->netdev_ops->ndo_init(dev);
5472 		if (ret) {
5473 			if (ret > 0)
5474 				ret = -EIO;
5475 			goto out;
5476 		}
5477 	}
5478 
5479 	dev->ifindex = dev_new_index(net);
5480 	if (dev->iflink == -1)
5481 		dev->iflink = dev->ifindex;
5482 
5483 	/* Transfer changeable features to wanted_features and enable
5484 	 * software offloads (GSO and GRO).
5485 	 */
5486 	dev->hw_features |= NETIF_F_SOFT_FEATURES;
5487 	dev->features |= NETIF_F_SOFT_FEATURES;
5488 	dev->wanted_features = dev->features & dev->hw_features;
5489 
5490 	/* Turn on no cache copy if HW is doing checksum */
5491 	dev->hw_features |= NETIF_F_NOCACHE_COPY;
5492 	if ((dev->features & NETIF_F_ALL_CSUM) &&
5493 	    !(dev->features & NETIF_F_NO_CSUM)) {
5494 		dev->wanted_features |= NETIF_F_NOCACHE_COPY;
5495 		dev->features |= NETIF_F_NOCACHE_COPY;
5496 	}
5497 
5498 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5499 	 */
5500 	dev->vlan_features |= NETIF_F_HIGHDMA;
5501 
5502 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5503 	ret = notifier_to_errno(ret);
5504 	if (ret)
5505 		goto err_uninit;
5506 
5507 	ret = netdev_register_kobject(dev);
5508 	if (ret)
5509 		goto err_uninit;
5510 	dev->reg_state = NETREG_REGISTERED;
5511 
5512 	__netdev_update_features(dev);
5513 
5514 	/*
5515 	 *	Default initial state at registry is that the
5516 	 *	device is present.
5517 	 */
5518 
5519 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5520 
5521 	dev_init_scheduler(dev);
5522 	dev_hold(dev);
5523 	list_netdevice(dev);
5524 
5525 	/* Notify protocols, that a new device appeared. */
5526 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5527 	ret = notifier_to_errno(ret);
5528 	if (ret) {
5529 		rollback_registered(dev);
5530 		dev->reg_state = NETREG_UNREGISTERED;
5531 	}
5532 	/*
5533 	 *	Prevent userspace races by waiting until the network
5534 	 *	device is fully setup before sending notifications.
5535 	 */
5536 	if (!dev->rtnl_link_ops ||
5537 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5538 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5539 
5540 out:
5541 	return ret;
5542 
5543 err_uninit:
5544 	if (dev->netdev_ops->ndo_uninit)
5545 		dev->netdev_ops->ndo_uninit(dev);
5546 	goto out;
5547 }
5548 EXPORT_SYMBOL(register_netdevice);
5549 
5550 /**
5551  *	init_dummy_netdev	- init a dummy network device for NAPI
5552  *	@dev: device to init
5553  *
5554  *	This takes a network device structure and initialize the minimum
5555  *	amount of fields so it can be used to schedule NAPI polls without
5556  *	registering a full blown interface. This is to be used by drivers
5557  *	that need to tie several hardware interfaces to a single NAPI
5558  *	poll scheduler due to HW limitations.
5559  */
5560 int init_dummy_netdev(struct net_device *dev)
5561 {
5562 	/* Clear everything. Note we don't initialize spinlocks
5563 	 * are they aren't supposed to be taken by any of the
5564 	 * NAPI code and this dummy netdev is supposed to be
5565 	 * only ever used for NAPI polls
5566 	 */
5567 	memset(dev, 0, sizeof(struct net_device));
5568 
5569 	/* make sure we BUG if trying to hit standard
5570 	 * register/unregister code path
5571 	 */
5572 	dev->reg_state = NETREG_DUMMY;
5573 
5574 	/* NAPI wants this */
5575 	INIT_LIST_HEAD(&dev->napi_list);
5576 
5577 	/* a dummy interface is started by default */
5578 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5579 	set_bit(__LINK_STATE_START, &dev->state);
5580 
5581 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
5582 	 * because users of this 'device' dont need to change
5583 	 * its refcount.
5584 	 */
5585 
5586 	return 0;
5587 }
5588 EXPORT_SYMBOL_GPL(init_dummy_netdev);
5589 
5590 
5591 /**
5592  *	register_netdev	- register a network device
5593  *	@dev: device to register
5594  *
5595  *	Take a completed network device structure and add it to the kernel
5596  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5597  *	chain. 0 is returned on success. A negative errno code is returned
5598  *	on a failure to set up the device, or if the name is a duplicate.
5599  *
5600  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
5601  *	and expands the device name if you passed a format string to
5602  *	alloc_netdev.
5603  */
5604 int register_netdev(struct net_device *dev)
5605 {
5606 	int err;
5607 
5608 	rtnl_lock();
5609 	err = register_netdevice(dev);
5610 	rtnl_unlock();
5611 	return err;
5612 }
5613 EXPORT_SYMBOL(register_netdev);
5614 
5615 int netdev_refcnt_read(const struct net_device *dev)
5616 {
5617 	int i, refcnt = 0;
5618 
5619 	for_each_possible_cpu(i)
5620 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
5621 	return refcnt;
5622 }
5623 EXPORT_SYMBOL(netdev_refcnt_read);
5624 
5625 /*
5626  * netdev_wait_allrefs - wait until all references are gone.
5627  *
5628  * This is called when unregistering network devices.
5629  *
5630  * Any protocol or device that holds a reference should register
5631  * for netdevice notification, and cleanup and put back the
5632  * reference if they receive an UNREGISTER event.
5633  * We can get stuck here if buggy protocols don't correctly
5634  * call dev_put.
5635  */
5636 static void netdev_wait_allrefs(struct net_device *dev)
5637 {
5638 	unsigned long rebroadcast_time, warning_time;
5639 	int refcnt;
5640 
5641 	linkwatch_forget_dev(dev);
5642 
5643 	rebroadcast_time = warning_time = jiffies;
5644 	refcnt = netdev_refcnt_read(dev);
5645 
5646 	while (refcnt != 0) {
5647 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5648 			rtnl_lock();
5649 
5650 			/* Rebroadcast unregister notification */
5651 			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5652 			/* don't resend NETDEV_UNREGISTER_BATCH, _BATCH users
5653 			 * should have already handle it the first time */
5654 
5655 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
5656 				     &dev->state)) {
5657 				/* We must not have linkwatch events
5658 				 * pending on unregister. If this
5659 				 * happens, we simply run the queue
5660 				 * unscheduled, resulting in a noop
5661 				 * for this device.
5662 				 */
5663 				linkwatch_run_queue();
5664 			}
5665 
5666 			__rtnl_unlock();
5667 
5668 			rebroadcast_time = jiffies;
5669 		}
5670 
5671 		msleep(250);
5672 
5673 		refcnt = netdev_refcnt_read(dev);
5674 
5675 		if (time_after(jiffies, warning_time + 10 * HZ)) {
5676 			printk(KERN_EMERG "unregister_netdevice: "
5677 			       "waiting for %s to become free. Usage "
5678 			       "count = %d\n",
5679 			       dev->name, refcnt);
5680 			warning_time = jiffies;
5681 		}
5682 	}
5683 }
5684 
5685 /* The sequence is:
5686  *
5687  *	rtnl_lock();
5688  *	...
5689  *	register_netdevice(x1);
5690  *	register_netdevice(x2);
5691  *	...
5692  *	unregister_netdevice(y1);
5693  *	unregister_netdevice(y2);
5694  *      ...
5695  *	rtnl_unlock();
5696  *	free_netdev(y1);
5697  *	free_netdev(y2);
5698  *
5699  * We are invoked by rtnl_unlock().
5700  * This allows us to deal with problems:
5701  * 1) We can delete sysfs objects which invoke hotplug
5702  *    without deadlocking with linkwatch via keventd.
5703  * 2) Since we run with the RTNL semaphore not held, we can sleep
5704  *    safely in order to wait for the netdev refcnt to drop to zero.
5705  *
5706  * We must not return until all unregister events added during
5707  * the interval the lock was held have been completed.
5708  */
5709 void netdev_run_todo(void)
5710 {
5711 	struct list_head list;
5712 
5713 	/* Snapshot list, allow later requests */
5714 	list_replace_init(&net_todo_list, &list);
5715 
5716 	__rtnl_unlock();
5717 
5718 	while (!list_empty(&list)) {
5719 		struct net_device *dev
5720 			= list_first_entry(&list, struct net_device, todo_list);
5721 		list_del(&dev->todo_list);
5722 
5723 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5724 			printk(KERN_ERR "network todo '%s' but state %d\n",
5725 			       dev->name, dev->reg_state);
5726 			dump_stack();
5727 			continue;
5728 		}
5729 
5730 		dev->reg_state = NETREG_UNREGISTERED;
5731 
5732 		on_each_cpu(flush_backlog, dev, 1);
5733 
5734 		netdev_wait_allrefs(dev);
5735 
5736 		/* paranoia */
5737 		BUG_ON(netdev_refcnt_read(dev));
5738 		WARN_ON(rcu_dereference_raw(dev->ip_ptr));
5739 		WARN_ON(rcu_dereference_raw(dev->ip6_ptr));
5740 		WARN_ON(dev->dn_ptr);
5741 
5742 		if (dev->destructor)
5743 			dev->destructor(dev);
5744 
5745 		/* Free network device */
5746 		kobject_put(&dev->dev.kobj);
5747 	}
5748 }
5749 
5750 /* Convert net_device_stats to rtnl_link_stats64.  They have the same
5751  * fields in the same order, with only the type differing.
5752  */
5753 static void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
5754 				    const struct net_device_stats *netdev_stats)
5755 {
5756 #if BITS_PER_LONG == 64
5757         BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
5758         memcpy(stats64, netdev_stats, sizeof(*stats64));
5759 #else
5760 	size_t i, n = sizeof(*stats64) / sizeof(u64);
5761 	const unsigned long *src = (const unsigned long *)netdev_stats;
5762 	u64 *dst = (u64 *)stats64;
5763 
5764 	BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
5765 		     sizeof(*stats64) / sizeof(u64));
5766 	for (i = 0; i < n; i++)
5767 		dst[i] = src[i];
5768 #endif
5769 }
5770 
5771 /**
5772  *	dev_get_stats	- get network device statistics
5773  *	@dev: device to get statistics from
5774  *	@storage: place to store stats
5775  *
5776  *	Get network statistics from device. Return @storage.
5777  *	The device driver may provide its own method by setting
5778  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
5779  *	otherwise the internal statistics structure is used.
5780  */
5781 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
5782 					struct rtnl_link_stats64 *storage)
5783 {
5784 	const struct net_device_ops *ops = dev->netdev_ops;
5785 
5786 	if (ops->ndo_get_stats64) {
5787 		memset(storage, 0, sizeof(*storage));
5788 		ops->ndo_get_stats64(dev, storage);
5789 	} else if (ops->ndo_get_stats) {
5790 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
5791 	} else {
5792 		netdev_stats_to_stats64(storage, &dev->stats);
5793 	}
5794 	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
5795 	return storage;
5796 }
5797 EXPORT_SYMBOL(dev_get_stats);
5798 
5799 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
5800 {
5801 	struct netdev_queue *queue = dev_ingress_queue(dev);
5802 
5803 #ifdef CONFIG_NET_CLS_ACT
5804 	if (queue)
5805 		return queue;
5806 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
5807 	if (!queue)
5808 		return NULL;
5809 	netdev_init_one_queue(dev, queue, NULL);
5810 	queue->qdisc = &noop_qdisc;
5811 	queue->qdisc_sleeping = &noop_qdisc;
5812 	rcu_assign_pointer(dev->ingress_queue, queue);
5813 #endif
5814 	return queue;
5815 }
5816 
5817 /**
5818  *	alloc_netdev_mqs - allocate network device
5819  *	@sizeof_priv:	size of private data to allocate space for
5820  *	@name:		device name format string
5821  *	@setup:		callback to initialize device
5822  *	@txqs:		the number of TX subqueues to allocate
5823  *	@rxqs:		the number of RX subqueues to allocate
5824  *
5825  *	Allocates a struct net_device with private data area for driver use
5826  *	and performs basic initialization.  Also allocates subquue structs
5827  *	for each queue on the device.
5828  */
5829 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
5830 		void (*setup)(struct net_device *),
5831 		unsigned int txqs, unsigned int rxqs)
5832 {
5833 	struct net_device *dev;
5834 	size_t alloc_size;
5835 	struct net_device *p;
5836 
5837 	BUG_ON(strlen(name) >= sizeof(dev->name));
5838 
5839 	if (txqs < 1) {
5840 		pr_err("alloc_netdev: Unable to allocate device "
5841 		       "with zero queues.\n");
5842 		return NULL;
5843 	}
5844 
5845 #ifdef CONFIG_RPS
5846 	if (rxqs < 1) {
5847 		pr_err("alloc_netdev: Unable to allocate device "
5848 		       "with zero RX queues.\n");
5849 		return NULL;
5850 	}
5851 #endif
5852 
5853 	alloc_size = sizeof(struct net_device);
5854 	if (sizeof_priv) {
5855 		/* ensure 32-byte alignment of private area */
5856 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5857 		alloc_size += sizeof_priv;
5858 	}
5859 	/* ensure 32-byte alignment of whole construct */
5860 	alloc_size += NETDEV_ALIGN - 1;
5861 
5862 	p = kzalloc(alloc_size, GFP_KERNEL);
5863 	if (!p) {
5864 		printk(KERN_ERR "alloc_netdev: Unable to allocate device.\n");
5865 		return NULL;
5866 	}
5867 
5868 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
5869 	dev->padded = (char *)dev - (char *)p;
5870 
5871 	dev->pcpu_refcnt = alloc_percpu(int);
5872 	if (!dev->pcpu_refcnt)
5873 		goto free_p;
5874 
5875 	if (dev_addr_init(dev))
5876 		goto free_pcpu;
5877 
5878 	dev_mc_init(dev);
5879 	dev_uc_init(dev);
5880 
5881 	dev_net_set(dev, &init_net);
5882 
5883 	dev->gso_max_size = GSO_MAX_SIZE;
5884 
5885 	INIT_LIST_HEAD(&dev->napi_list);
5886 	INIT_LIST_HEAD(&dev->unreg_list);
5887 	INIT_LIST_HEAD(&dev->link_watch_list);
5888 	dev->priv_flags = IFF_XMIT_DST_RELEASE;
5889 	setup(dev);
5890 
5891 	dev->num_tx_queues = txqs;
5892 	dev->real_num_tx_queues = txqs;
5893 	if (netif_alloc_netdev_queues(dev))
5894 		goto free_all;
5895 
5896 #ifdef CONFIG_RPS
5897 	dev->num_rx_queues = rxqs;
5898 	dev->real_num_rx_queues = rxqs;
5899 	if (netif_alloc_rx_queues(dev))
5900 		goto free_all;
5901 #endif
5902 
5903 	strcpy(dev->name, name);
5904 	dev->group = INIT_NETDEV_GROUP;
5905 	return dev;
5906 
5907 free_all:
5908 	free_netdev(dev);
5909 	return NULL;
5910 
5911 free_pcpu:
5912 	free_percpu(dev->pcpu_refcnt);
5913 	kfree(dev->_tx);
5914 #ifdef CONFIG_RPS
5915 	kfree(dev->_rx);
5916 #endif
5917 
5918 free_p:
5919 	kfree(p);
5920 	return NULL;
5921 }
5922 EXPORT_SYMBOL(alloc_netdev_mqs);
5923 
5924 /**
5925  *	free_netdev - free network device
5926  *	@dev: device
5927  *
5928  *	This function does the last stage of destroying an allocated device
5929  * 	interface. The reference to the device object is released.
5930  *	If this is the last reference then it will be freed.
5931  */
5932 void free_netdev(struct net_device *dev)
5933 {
5934 	struct napi_struct *p, *n;
5935 
5936 	release_net(dev_net(dev));
5937 
5938 	kfree(dev->_tx);
5939 #ifdef CONFIG_RPS
5940 	kfree(dev->_rx);
5941 #endif
5942 
5943 	kfree(rcu_dereference_raw(dev->ingress_queue));
5944 
5945 	/* Flush device addresses */
5946 	dev_addr_flush(dev);
5947 
5948 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
5949 		netif_napi_del(p);
5950 
5951 	free_percpu(dev->pcpu_refcnt);
5952 	dev->pcpu_refcnt = NULL;
5953 
5954 	/*  Compatibility with error handling in drivers */
5955 	if (dev->reg_state == NETREG_UNINITIALIZED) {
5956 		kfree((char *)dev - dev->padded);
5957 		return;
5958 	}
5959 
5960 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
5961 	dev->reg_state = NETREG_RELEASED;
5962 
5963 	/* will free via device release */
5964 	put_device(&dev->dev);
5965 }
5966 EXPORT_SYMBOL(free_netdev);
5967 
5968 /**
5969  *	synchronize_net -  Synchronize with packet receive processing
5970  *
5971  *	Wait for packets currently being received to be done.
5972  *	Does not block later packets from starting.
5973  */
5974 void synchronize_net(void)
5975 {
5976 	might_sleep();
5977 	if (rtnl_is_locked())
5978 		synchronize_rcu_expedited();
5979 	else
5980 		synchronize_rcu();
5981 }
5982 EXPORT_SYMBOL(synchronize_net);
5983 
5984 /**
5985  *	unregister_netdevice_queue - remove device from the kernel
5986  *	@dev: device
5987  *	@head: list
5988  *
5989  *	This function shuts down a device interface and removes it
5990  *	from the kernel tables.
5991  *	If head not NULL, device is queued to be unregistered later.
5992  *
5993  *	Callers must hold the rtnl semaphore.  You may want
5994  *	unregister_netdev() instead of this.
5995  */
5996 
5997 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
5998 {
5999 	ASSERT_RTNL();
6000 
6001 	if (head) {
6002 		list_move_tail(&dev->unreg_list, head);
6003 	} else {
6004 		rollback_registered(dev);
6005 		/* Finish processing unregister after unlock */
6006 		net_set_todo(dev);
6007 	}
6008 }
6009 EXPORT_SYMBOL(unregister_netdevice_queue);
6010 
6011 /**
6012  *	unregister_netdevice_many - unregister many devices
6013  *	@head: list of devices
6014  */
6015 void unregister_netdevice_many(struct list_head *head)
6016 {
6017 	struct net_device *dev;
6018 
6019 	if (!list_empty(head)) {
6020 		rollback_registered_many(head);
6021 		list_for_each_entry(dev, head, unreg_list)
6022 			net_set_todo(dev);
6023 	}
6024 }
6025 EXPORT_SYMBOL(unregister_netdevice_many);
6026 
6027 /**
6028  *	unregister_netdev - remove device from the kernel
6029  *	@dev: device
6030  *
6031  *	This function shuts down a device interface and removes it
6032  *	from the kernel tables.
6033  *
6034  *	This is just a wrapper for unregister_netdevice that takes
6035  *	the rtnl semaphore.  In general you want to use this and not
6036  *	unregister_netdevice.
6037  */
6038 void unregister_netdev(struct net_device *dev)
6039 {
6040 	rtnl_lock();
6041 	unregister_netdevice(dev);
6042 	rtnl_unlock();
6043 }
6044 EXPORT_SYMBOL(unregister_netdev);
6045 
6046 /**
6047  *	dev_change_net_namespace - move device to different nethost namespace
6048  *	@dev: device
6049  *	@net: network namespace
6050  *	@pat: If not NULL name pattern to try if the current device name
6051  *	      is already taken in the destination network namespace.
6052  *
6053  *	This function shuts down a device interface and moves it
6054  *	to a new network namespace. On success 0 is returned, on
6055  *	a failure a netagive errno code is returned.
6056  *
6057  *	Callers must hold the rtnl semaphore.
6058  */
6059 
6060 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
6061 {
6062 	int err;
6063 
6064 	ASSERT_RTNL();
6065 
6066 	/* Don't allow namespace local devices to be moved. */
6067 	err = -EINVAL;
6068 	if (dev->features & NETIF_F_NETNS_LOCAL)
6069 		goto out;
6070 
6071 	/* Ensure the device has been registrered */
6072 	err = -EINVAL;
6073 	if (dev->reg_state != NETREG_REGISTERED)
6074 		goto out;
6075 
6076 	/* Get out if there is nothing todo */
6077 	err = 0;
6078 	if (net_eq(dev_net(dev), net))
6079 		goto out;
6080 
6081 	/* Pick the destination device name, and ensure
6082 	 * we can use it in the destination network namespace.
6083 	 */
6084 	err = -EEXIST;
6085 	if (__dev_get_by_name(net, dev->name)) {
6086 		/* We get here if we can't use the current device name */
6087 		if (!pat)
6088 			goto out;
6089 		if (dev_get_valid_name(dev, pat) < 0)
6090 			goto out;
6091 	}
6092 
6093 	/*
6094 	 * And now a mini version of register_netdevice unregister_netdevice.
6095 	 */
6096 
6097 	/* If device is running close it first. */
6098 	dev_close(dev);
6099 
6100 	/* And unlink it from device chain */
6101 	err = -ENODEV;
6102 	unlist_netdevice(dev);
6103 
6104 	synchronize_net();
6105 
6106 	/* Shutdown queueing discipline. */
6107 	dev_shutdown(dev);
6108 
6109 	/* Notify protocols, that we are about to destroy
6110 	   this device. They should clean all the things.
6111 
6112 	   Note that dev->reg_state stays at NETREG_REGISTERED.
6113 	   This is wanted because this way 8021q and macvlan know
6114 	   the device is just moving and can keep their slaves up.
6115 	*/
6116 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6117 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
6118 	rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
6119 
6120 	/*
6121 	 *	Flush the unicast and multicast chains
6122 	 */
6123 	dev_uc_flush(dev);
6124 	dev_mc_flush(dev);
6125 
6126 	/* Actually switch the network namespace */
6127 	dev_net_set(dev, net);
6128 
6129 	/* If there is an ifindex conflict assign a new one */
6130 	if (__dev_get_by_index(net, dev->ifindex)) {
6131 		int iflink = (dev->iflink == dev->ifindex);
6132 		dev->ifindex = dev_new_index(net);
6133 		if (iflink)
6134 			dev->iflink = dev->ifindex;
6135 	}
6136 
6137 	/* Fixup kobjects */
6138 	err = device_rename(&dev->dev, dev->name);
6139 	WARN_ON(err);
6140 
6141 	/* Add the device back in the hashes */
6142 	list_netdevice(dev);
6143 
6144 	/* Notify protocols, that a new device appeared. */
6145 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
6146 
6147 	/*
6148 	 *	Prevent userspace races by waiting until the network
6149 	 *	device is fully setup before sending notifications.
6150 	 */
6151 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
6152 
6153 	synchronize_net();
6154 	err = 0;
6155 out:
6156 	return err;
6157 }
6158 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6159 
6160 static int dev_cpu_callback(struct notifier_block *nfb,
6161 			    unsigned long action,
6162 			    void *ocpu)
6163 {
6164 	struct sk_buff **list_skb;
6165 	struct sk_buff *skb;
6166 	unsigned int cpu, oldcpu = (unsigned long)ocpu;
6167 	struct softnet_data *sd, *oldsd;
6168 
6169 	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
6170 		return NOTIFY_OK;
6171 
6172 	local_irq_disable();
6173 	cpu = smp_processor_id();
6174 	sd = &per_cpu(softnet_data, cpu);
6175 	oldsd = &per_cpu(softnet_data, oldcpu);
6176 
6177 	/* Find end of our completion_queue. */
6178 	list_skb = &sd->completion_queue;
6179 	while (*list_skb)
6180 		list_skb = &(*list_skb)->next;
6181 	/* Append completion queue from offline CPU. */
6182 	*list_skb = oldsd->completion_queue;
6183 	oldsd->completion_queue = NULL;
6184 
6185 	/* Append output queue from offline CPU. */
6186 	if (oldsd->output_queue) {
6187 		*sd->output_queue_tailp = oldsd->output_queue;
6188 		sd->output_queue_tailp = oldsd->output_queue_tailp;
6189 		oldsd->output_queue = NULL;
6190 		oldsd->output_queue_tailp = &oldsd->output_queue;
6191 	}
6192 	/* Append NAPI poll list from offline CPU. */
6193 	if (!list_empty(&oldsd->poll_list)) {
6194 		list_splice_init(&oldsd->poll_list, &sd->poll_list);
6195 		raise_softirq_irqoff(NET_RX_SOFTIRQ);
6196 	}
6197 
6198 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
6199 	local_irq_enable();
6200 
6201 	/* Process offline CPU's input_pkt_queue */
6202 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
6203 		netif_rx(skb);
6204 		input_queue_head_incr(oldsd);
6205 	}
6206 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6207 		netif_rx(skb);
6208 		input_queue_head_incr(oldsd);
6209 	}
6210 
6211 	return NOTIFY_OK;
6212 }
6213 
6214 
6215 /**
6216  *	netdev_increment_features - increment feature set by one
6217  *	@all: current feature set
6218  *	@one: new feature set
6219  *	@mask: mask feature set
6220  *
6221  *	Computes a new feature set after adding a device with feature set
6222  *	@one to the master device with current feature set @all.  Will not
6223  *	enable anything that is off in @mask. Returns the new feature set.
6224  */
6225 u32 netdev_increment_features(u32 all, u32 one, u32 mask)
6226 {
6227 	if (mask & NETIF_F_GEN_CSUM)
6228 		mask |= NETIF_F_ALL_CSUM;
6229 	mask |= NETIF_F_VLAN_CHALLENGED;
6230 
6231 	all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
6232 	all &= one | ~NETIF_F_ALL_FOR_ALL;
6233 
6234 	/* If device needs checksumming, downgrade to it. */
6235 	if (all & (NETIF_F_ALL_CSUM & ~NETIF_F_NO_CSUM))
6236 		all &= ~NETIF_F_NO_CSUM;
6237 
6238 	/* If one device supports hw checksumming, set for all. */
6239 	if (all & NETIF_F_GEN_CSUM)
6240 		all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6241 
6242 	return all;
6243 }
6244 EXPORT_SYMBOL(netdev_increment_features);
6245 
6246 static struct hlist_head *netdev_create_hash(void)
6247 {
6248 	int i;
6249 	struct hlist_head *hash;
6250 
6251 	hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
6252 	if (hash != NULL)
6253 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
6254 			INIT_HLIST_HEAD(&hash[i]);
6255 
6256 	return hash;
6257 }
6258 
6259 /* Initialize per network namespace state */
6260 static int __net_init netdev_init(struct net *net)
6261 {
6262 	INIT_LIST_HEAD(&net->dev_base_head);
6263 
6264 	net->dev_name_head = netdev_create_hash();
6265 	if (net->dev_name_head == NULL)
6266 		goto err_name;
6267 
6268 	net->dev_index_head = netdev_create_hash();
6269 	if (net->dev_index_head == NULL)
6270 		goto err_idx;
6271 
6272 	return 0;
6273 
6274 err_idx:
6275 	kfree(net->dev_name_head);
6276 err_name:
6277 	return -ENOMEM;
6278 }
6279 
6280 /**
6281  *	netdev_drivername - network driver for the device
6282  *	@dev: network device
6283  *
6284  *	Determine network driver for device.
6285  */
6286 const char *netdev_drivername(const struct net_device *dev)
6287 {
6288 	const struct device_driver *driver;
6289 	const struct device *parent;
6290 	const char *empty = "";
6291 
6292 	parent = dev->dev.parent;
6293 	if (!parent)
6294 		return empty;
6295 
6296 	driver = parent->driver;
6297 	if (driver && driver->name)
6298 		return driver->name;
6299 	return empty;
6300 }
6301 
6302 static int __netdev_printk(const char *level, const struct net_device *dev,
6303 			   struct va_format *vaf)
6304 {
6305 	int r;
6306 
6307 	if (dev && dev->dev.parent)
6308 		r = dev_printk(level, dev->dev.parent, "%s: %pV",
6309 			       netdev_name(dev), vaf);
6310 	else if (dev)
6311 		r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6312 	else
6313 		r = printk("%s(NULL net_device): %pV", level, vaf);
6314 
6315 	return r;
6316 }
6317 
6318 int netdev_printk(const char *level, const struct net_device *dev,
6319 		  const char *format, ...)
6320 {
6321 	struct va_format vaf;
6322 	va_list args;
6323 	int r;
6324 
6325 	va_start(args, format);
6326 
6327 	vaf.fmt = format;
6328 	vaf.va = &args;
6329 
6330 	r = __netdev_printk(level, dev, &vaf);
6331 	va_end(args);
6332 
6333 	return r;
6334 }
6335 EXPORT_SYMBOL(netdev_printk);
6336 
6337 #define define_netdev_printk_level(func, level)			\
6338 int func(const struct net_device *dev, const char *fmt, ...)	\
6339 {								\
6340 	int r;							\
6341 	struct va_format vaf;					\
6342 	va_list args;						\
6343 								\
6344 	va_start(args, fmt);					\
6345 								\
6346 	vaf.fmt = fmt;						\
6347 	vaf.va = &args;						\
6348 								\
6349 	r = __netdev_printk(level, dev, &vaf);			\
6350 	va_end(args);						\
6351 								\
6352 	return r;						\
6353 }								\
6354 EXPORT_SYMBOL(func);
6355 
6356 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
6357 define_netdev_printk_level(netdev_alert, KERN_ALERT);
6358 define_netdev_printk_level(netdev_crit, KERN_CRIT);
6359 define_netdev_printk_level(netdev_err, KERN_ERR);
6360 define_netdev_printk_level(netdev_warn, KERN_WARNING);
6361 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
6362 define_netdev_printk_level(netdev_info, KERN_INFO);
6363 
6364 static void __net_exit netdev_exit(struct net *net)
6365 {
6366 	kfree(net->dev_name_head);
6367 	kfree(net->dev_index_head);
6368 }
6369 
6370 static struct pernet_operations __net_initdata netdev_net_ops = {
6371 	.init = netdev_init,
6372 	.exit = netdev_exit,
6373 };
6374 
6375 static void __net_exit default_device_exit(struct net *net)
6376 {
6377 	struct net_device *dev, *aux;
6378 	/*
6379 	 * Push all migratable network devices back to the
6380 	 * initial network namespace
6381 	 */
6382 	rtnl_lock();
6383 	for_each_netdev_safe(net, dev, aux) {
6384 		int err;
6385 		char fb_name[IFNAMSIZ];
6386 
6387 		/* Ignore unmoveable devices (i.e. loopback) */
6388 		if (dev->features & NETIF_F_NETNS_LOCAL)
6389 			continue;
6390 
6391 		/* Leave virtual devices for the generic cleanup */
6392 		if (dev->rtnl_link_ops)
6393 			continue;
6394 
6395 		/* Push remaining network devices to init_net */
6396 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
6397 		err = dev_change_net_namespace(dev, &init_net, fb_name);
6398 		if (err) {
6399 			printk(KERN_EMERG "%s: failed to move %s to init_net: %d\n",
6400 				__func__, dev->name, err);
6401 			BUG();
6402 		}
6403 	}
6404 	rtnl_unlock();
6405 }
6406 
6407 static void __net_exit default_device_exit_batch(struct list_head *net_list)
6408 {
6409 	/* At exit all network devices most be removed from a network
6410 	 * namespace.  Do this in the reverse order of registration.
6411 	 * Do this across as many network namespaces as possible to
6412 	 * improve batching efficiency.
6413 	 */
6414 	struct net_device *dev;
6415 	struct net *net;
6416 	LIST_HEAD(dev_kill_list);
6417 
6418 	rtnl_lock();
6419 	list_for_each_entry(net, net_list, exit_list) {
6420 		for_each_netdev_reverse(net, dev) {
6421 			if (dev->rtnl_link_ops)
6422 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
6423 			else
6424 				unregister_netdevice_queue(dev, &dev_kill_list);
6425 		}
6426 	}
6427 	unregister_netdevice_many(&dev_kill_list);
6428 	list_del(&dev_kill_list);
6429 	rtnl_unlock();
6430 }
6431 
6432 static struct pernet_operations __net_initdata default_device_ops = {
6433 	.exit = default_device_exit,
6434 	.exit_batch = default_device_exit_batch,
6435 };
6436 
6437 /*
6438  *	Initialize the DEV module. At boot time this walks the device list and
6439  *	unhooks any devices that fail to initialise (normally hardware not
6440  *	present) and leaves us with a valid list of present and active devices.
6441  *
6442  */
6443 
6444 /*
6445  *       This is called single threaded during boot, so no need
6446  *       to take the rtnl semaphore.
6447  */
6448 static int __init net_dev_init(void)
6449 {
6450 	int i, rc = -ENOMEM;
6451 
6452 	BUG_ON(!dev_boot_phase);
6453 
6454 	if (dev_proc_init())
6455 		goto out;
6456 
6457 	if (netdev_kobject_init())
6458 		goto out;
6459 
6460 	INIT_LIST_HEAD(&ptype_all);
6461 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
6462 		INIT_LIST_HEAD(&ptype_base[i]);
6463 
6464 	if (register_pernet_subsys(&netdev_net_ops))
6465 		goto out;
6466 
6467 	/*
6468 	 *	Initialise the packet receive queues.
6469 	 */
6470 
6471 	for_each_possible_cpu(i) {
6472 		struct softnet_data *sd = &per_cpu(softnet_data, i);
6473 
6474 		memset(sd, 0, sizeof(*sd));
6475 		skb_queue_head_init(&sd->input_pkt_queue);
6476 		skb_queue_head_init(&sd->process_queue);
6477 		sd->completion_queue = NULL;
6478 		INIT_LIST_HEAD(&sd->poll_list);
6479 		sd->output_queue = NULL;
6480 		sd->output_queue_tailp = &sd->output_queue;
6481 #ifdef CONFIG_RPS
6482 		sd->csd.func = rps_trigger_softirq;
6483 		sd->csd.info = sd;
6484 		sd->csd.flags = 0;
6485 		sd->cpu = i;
6486 #endif
6487 
6488 		sd->backlog.poll = process_backlog;
6489 		sd->backlog.weight = weight_p;
6490 		sd->backlog.gro_list = NULL;
6491 		sd->backlog.gro_count = 0;
6492 	}
6493 
6494 	dev_boot_phase = 0;
6495 
6496 	/* The loopback device is special if any other network devices
6497 	 * is present in a network namespace the loopback device must
6498 	 * be present. Since we now dynamically allocate and free the
6499 	 * loopback device ensure this invariant is maintained by
6500 	 * keeping the loopback device as the first device on the
6501 	 * list of network devices.  Ensuring the loopback devices
6502 	 * is the first device that appears and the last network device
6503 	 * that disappears.
6504 	 */
6505 	if (register_pernet_device(&loopback_net_ops))
6506 		goto out;
6507 
6508 	if (register_pernet_device(&default_device_ops))
6509 		goto out;
6510 
6511 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
6512 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
6513 
6514 	hotcpu_notifier(dev_cpu_callback, 0);
6515 	dst_init();
6516 	dev_mcast_init();
6517 	rc = 0;
6518 out:
6519 	return rc;
6520 }
6521 
6522 subsys_initcall(net_dev_init);
6523 
6524 static int __init initialize_hashrnd(void)
6525 {
6526 	get_random_bytes(&hashrnd, sizeof(hashrnd));
6527 	return 0;
6528 }
6529 
6530 late_initcall_sync(initialize_hashrnd);
6531 
6532