xref: /linux/net/core/dev.c (revision 9a58a80a701bdb2d220cdab4914218df5b48d781)
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/sched.h>
84 #include <linux/mutex.h>
85 #include <linux/string.h>
86 #include <linux/mm.h>
87 #include <linux/socket.h>
88 #include <linux/sockios.h>
89 #include <linux/errno.h>
90 #include <linux/interrupt.h>
91 #include <linux/if_ether.h>
92 #include <linux/netdevice.h>
93 #include <linux/etherdevice.h>
94 #include <linux/ethtool.h>
95 #include <linux/notifier.h>
96 #include <linux/skbuff.h>
97 #include <net/net_namespace.h>
98 #include <net/sock.h>
99 #include <linux/rtnetlink.h>
100 #include <linux/proc_fs.h>
101 #include <linux/seq_file.h>
102 #include <linux/stat.h>
103 #include <linux/if_bridge.h>
104 #include <linux/if_macvlan.h>
105 #include <net/dst.h>
106 #include <net/pkt_sched.h>
107 #include <net/checksum.h>
108 #include <net/xfrm.h>
109 #include <linux/highmem.h>
110 #include <linux/init.h>
111 #include <linux/kmod.h>
112 #include <linux/module.h>
113 #include <linux/netpoll.h>
114 #include <linux/rcupdate.h>
115 #include <linux/delay.h>
116 #include <net/wext.h>
117 #include <net/iw_handler.h>
118 #include <asm/current.h>
119 #include <linux/audit.h>
120 #include <linux/dmaengine.h>
121 #include <linux/err.h>
122 #include <linux/ctype.h>
123 #include <linux/if_arp.h>
124 #include <linux/if_vlan.h>
125 #include <linux/ip.h>
126 #include <net/ip.h>
127 #include <linux/ipv6.h>
128 #include <linux/in.h>
129 #include <linux/jhash.h>
130 #include <linux/random.h>
131 #include <trace/events/napi.h>
132 
133 #include "net-sysfs.h"
134 
135 /* Instead of increasing this, you should create a hash table. */
136 #define MAX_GRO_SKBS 8
137 
138 /* This should be increased if a protocol with a bigger head is added. */
139 #define GRO_MAX_HEAD (MAX_HEADER + 128)
140 
141 /*
142  *	The list of packet types we will receive (as opposed to discard)
143  *	and the routines to invoke.
144  *
145  *	Why 16. Because with 16 the only overlap we get on a hash of the
146  *	low nibble of the protocol value is RARP/SNAP/X.25.
147  *
148  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
149  *             sure which should go first, but I bet it won't make much
150  *             difference if we are running VLANs.  The good news is that
151  *             this protocol won't be in the list unless compiled in, so
152  *             the average user (w/out VLANs) will not be adversely affected.
153  *             --BLG
154  *
155  *		0800	IP
156  *		8100    802.1Q VLAN
157  *		0001	802.3
158  *		0002	AX.25
159  *		0004	802.2
160  *		8035	RARP
161  *		0005	SNAP
162  *		0805	X.25
163  *		0806	ARP
164  *		8137	IPX
165  *		0009	Localtalk
166  *		86DD	IPv6
167  */
168 
169 #define PTYPE_HASH_SIZE	(16)
170 #define PTYPE_HASH_MASK	(PTYPE_HASH_SIZE - 1)
171 
172 static DEFINE_SPINLOCK(ptype_lock);
173 static struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
174 static struct list_head ptype_all __read_mostly;	/* Taps */
175 
176 /*
177  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
178  * semaphore.
179  *
180  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
181  *
182  * Writers must hold the rtnl semaphore while they loop through the
183  * dev_base_head list, and hold dev_base_lock for writing when they do the
184  * actual updates.  This allows pure readers to access the list even
185  * while a writer is preparing to update it.
186  *
187  * To put it another way, dev_base_lock is held for writing only to
188  * protect against pure readers; the rtnl semaphore provides the
189  * protection against other writers.
190  *
191  * See, for example usages, register_netdevice() and
192  * unregister_netdevice(), which must be called with the rtnl
193  * semaphore held.
194  */
195 DEFINE_RWLOCK(dev_base_lock);
196 EXPORT_SYMBOL(dev_base_lock);
197 
198 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
199 {
200 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
201 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
202 }
203 
204 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
205 {
206 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
207 }
208 
209 /* Device list insertion */
210 static int list_netdevice(struct net_device *dev)
211 {
212 	struct net *net = dev_net(dev);
213 
214 	ASSERT_RTNL();
215 
216 	write_lock_bh(&dev_base_lock);
217 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
218 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
219 	hlist_add_head_rcu(&dev->index_hlist,
220 			   dev_index_hash(net, dev->ifindex));
221 	write_unlock_bh(&dev_base_lock);
222 	return 0;
223 }
224 
225 /* Device list removal
226  * caller must respect a RCU grace period before freeing/reusing dev
227  */
228 static void unlist_netdevice(struct net_device *dev)
229 {
230 	ASSERT_RTNL();
231 
232 	/* Unlink dev from the device chain */
233 	write_lock_bh(&dev_base_lock);
234 	list_del_rcu(&dev->dev_list);
235 	hlist_del_rcu(&dev->name_hlist);
236 	hlist_del_rcu(&dev->index_hlist);
237 	write_unlock_bh(&dev_base_lock);
238 }
239 
240 /*
241  *	Our notifier list
242  */
243 
244 static RAW_NOTIFIER_HEAD(netdev_chain);
245 
246 /*
247  *	Device drivers call our routines to queue packets here. We empty the
248  *	queue in the local softnet handler.
249  */
250 
251 DEFINE_PER_CPU(struct softnet_data, softnet_data);
252 EXPORT_PER_CPU_SYMBOL(softnet_data);
253 
254 #ifdef CONFIG_LOCKDEP
255 /*
256  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
257  * according to dev->type
258  */
259 static const unsigned short netdev_lock_type[] =
260 	{ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
261 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
262 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
263 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
264 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
265 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
266 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
267 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
268 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
269 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
270 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
271 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
272 	 ARPHRD_FCFABRIC, ARPHRD_IEEE802_TR, ARPHRD_IEEE80211,
273 	 ARPHRD_IEEE80211_PRISM, ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET,
274 	 ARPHRD_PHONET_PIPE, ARPHRD_IEEE802154,
275 	 ARPHRD_VOID, ARPHRD_NONE};
276 
277 static const char *const netdev_lock_name[] =
278 	{"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
279 	 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
280 	 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
281 	 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
282 	 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
283 	 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
284 	 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
285 	 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
286 	 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
287 	 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
288 	 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
289 	 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
290 	 "_xmit_FCFABRIC", "_xmit_IEEE802_TR", "_xmit_IEEE80211",
291 	 "_xmit_IEEE80211_PRISM", "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET",
292 	 "_xmit_PHONET_PIPE", "_xmit_IEEE802154",
293 	 "_xmit_VOID", "_xmit_NONE"};
294 
295 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
296 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
297 
298 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
299 {
300 	int i;
301 
302 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
303 		if (netdev_lock_type[i] == dev_type)
304 			return i;
305 	/* the last key is used by default */
306 	return ARRAY_SIZE(netdev_lock_type) - 1;
307 }
308 
309 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
310 						 unsigned short dev_type)
311 {
312 	int i;
313 
314 	i = netdev_lock_pos(dev_type);
315 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
316 				   netdev_lock_name[i]);
317 }
318 
319 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
320 {
321 	int i;
322 
323 	i = netdev_lock_pos(dev->type);
324 	lockdep_set_class_and_name(&dev->addr_list_lock,
325 				   &netdev_addr_lock_key[i],
326 				   netdev_lock_name[i]);
327 }
328 #else
329 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
330 						 unsigned short dev_type)
331 {
332 }
333 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
334 {
335 }
336 #endif
337 
338 /*******************************************************************************
339 
340 		Protocol management and registration routines
341 
342 *******************************************************************************/
343 
344 /*
345  *	Add a protocol ID to the list. Now that the input handler is
346  *	smarter we can dispense with all the messy stuff that used to be
347  *	here.
348  *
349  *	BEWARE!!! Protocol handlers, mangling input packets,
350  *	MUST BE last in hash buckets and checking protocol handlers
351  *	MUST start from promiscuous ptype_all chain in net_bh.
352  *	It is true now, do not change it.
353  *	Explanation follows: if protocol handler, mangling packet, will
354  *	be the first on list, it is not able to sense, that packet
355  *	is cloned and should be copied-on-write, so that it will
356  *	change it and subsequent readers will get broken packet.
357  *							--ANK (980803)
358  */
359 
360 /**
361  *	dev_add_pack - add packet handler
362  *	@pt: packet type declaration
363  *
364  *	Add a protocol handler to the networking stack. The passed &packet_type
365  *	is linked into kernel lists and may not be freed until it has been
366  *	removed from the kernel lists.
367  *
368  *	This call does not sleep therefore it can not
369  *	guarantee all CPU's that are in middle of receiving packets
370  *	will see the new packet type (until the next received packet).
371  */
372 
373 void dev_add_pack(struct packet_type *pt)
374 {
375 	int hash;
376 
377 	spin_lock_bh(&ptype_lock);
378 	if (pt->type == htons(ETH_P_ALL))
379 		list_add_rcu(&pt->list, &ptype_all);
380 	else {
381 		hash = ntohs(pt->type) & PTYPE_HASH_MASK;
382 		list_add_rcu(&pt->list, &ptype_base[hash]);
383 	}
384 	spin_unlock_bh(&ptype_lock);
385 }
386 EXPORT_SYMBOL(dev_add_pack);
387 
388 /**
389  *	__dev_remove_pack	 - remove packet handler
390  *	@pt: packet type declaration
391  *
392  *	Remove a protocol handler that was previously added to the kernel
393  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
394  *	from the kernel lists and can be freed or reused once this function
395  *	returns.
396  *
397  *      The packet type might still be in use by receivers
398  *	and must not be freed until after all the CPU's have gone
399  *	through a quiescent state.
400  */
401 void __dev_remove_pack(struct packet_type *pt)
402 {
403 	struct list_head *head;
404 	struct packet_type *pt1;
405 
406 	spin_lock_bh(&ptype_lock);
407 
408 	if (pt->type == htons(ETH_P_ALL))
409 		head = &ptype_all;
410 	else
411 		head = &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
412 
413 	list_for_each_entry(pt1, head, list) {
414 		if (pt == pt1) {
415 			list_del_rcu(&pt->list);
416 			goto out;
417 		}
418 	}
419 
420 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
421 out:
422 	spin_unlock_bh(&ptype_lock);
423 }
424 EXPORT_SYMBOL(__dev_remove_pack);
425 
426 /**
427  *	dev_remove_pack	 - remove packet handler
428  *	@pt: packet type declaration
429  *
430  *	Remove a protocol handler that was previously added to the kernel
431  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
432  *	from the kernel lists and can be freed or reused once this function
433  *	returns.
434  *
435  *	This call sleeps to guarantee that no CPU is looking at the packet
436  *	type after return.
437  */
438 void dev_remove_pack(struct packet_type *pt)
439 {
440 	__dev_remove_pack(pt);
441 
442 	synchronize_net();
443 }
444 EXPORT_SYMBOL(dev_remove_pack);
445 
446 /******************************************************************************
447 
448 		      Device Boot-time Settings Routines
449 
450 *******************************************************************************/
451 
452 /* Boot time configuration table */
453 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
454 
455 /**
456  *	netdev_boot_setup_add	- add new setup entry
457  *	@name: name of the device
458  *	@map: configured settings for the device
459  *
460  *	Adds new setup entry to the dev_boot_setup list.  The function
461  *	returns 0 on error and 1 on success.  This is a generic routine to
462  *	all netdevices.
463  */
464 static int netdev_boot_setup_add(char *name, struct ifmap *map)
465 {
466 	struct netdev_boot_setup *s;
467 	int i;
468 
469 	s = dev_boot_setup;
470 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
471 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
472 			memset(s[i].name, 0, sizeof(s[i].name));
473 			strlcpy(s[i].name, name, IFNAMSIZ);
474 			memcpy(&s[i].map, map, sizeof(s[i].map));
475 			break;
476 		}
477 	}
478 
479 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
480 }
481 
482 /**
483  *	netdev_boot_setup_check	- check boot time settings
484  *	@dev: the netdevice
485  *
486  * 	Check boot time settings for the device.
487  *	The found settings are set for the device to be used
488  *	later in the device probing.
489  *	Returns 0 if no settings found, 1 if they are.
490  */
491 int netdev_boot_setup_check(struct net_device *dev)
492 {
493 	struct netdev_boot_setup *s = dev_boot_setup;
494 	int i;
495 
496 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
497 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
498 		    !strcmp(dev->name, s[i].name)) {
499 			dev->irq 	= s[i].map.irq;
500 			dev->base_addr 	= s[i].map.base_addr;
501 			dev->mem_start 	= s[i].map.mem_start;
502 			dev->mem_end 	= s[i].map.mem_end;
503 			return 1;
504 		}
505 	}
506 	return 0;
507 }
508 EXPORT_SYMBOL(netdev_boot_setup_check);
509 
510 
511 /**
512  *	netdev_boot_base	- get address from boot time settings
513  *	@prefix: prefix for network device
514  *	@unit: id for network device
515  *
516  * 	Check boot time settings for the base address of device.
517  *	The found settings are set for the device to be used
518  *	later in the device probing.
519  *	Returns 0 if no settings found.
520  */
521 unsigned long netdev_boot_base(const char *prefix, int unit)
522 {
523 	const struct netdev_boot_setup *s = dev_boot_setup;
524 	char name[IFNAMSIZ];
525 	int i;
526 
527 	sprintf(name, "%s%d", prefix, unit);
528 
529 	/*
530 	 * If device already registered then return base of 1
531 	 * to indicate not to probe for this interface
532 	 */
533 	if (__dev_get_by_name(&init_net, name))
534 		return 1;
535 
536 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
537 		if (!strcmp(name, s[i].name))
538 			return s[i].map.base_addr;
539 	return 0;
540 }
541 
542 /*
543  * Saves at boot time configured settings for any netdevice.
544  */
545 int __init netdev_boot_setup(char *str)
546 {
547 	int ints[5];
548 	struct ifmap map;
549 
550 	str = get_options(str, ARRAY_SIZE(ints), ints);
551 	if (!str || !*str)
552 		return 0;
553 
554 	/* Save settings */
555 	memset(&map, 0, sizeof(map));
556 	if (ints[0] > 0)
557 		map.irq = ints[1];
558 	if (ints[0] > 1)
559 		map.base_addr = ints[2];
560 	if (ints[0] > 2)
561 		map.mem_start = ints[3];
562 	if (ints[0] > 3)
563 		map.mem_end = ints[4];
564 
565 	/* Add new entry to the list */
566 	return netdev_boot_setup_add(str, &map);
567 }
568 
569 __setup("netdev=", netdev_boot_setup);
570 
571 /*******************************************************************************
572 
573 			    Device Interface Subroutines
574 
575 *******************************************************************************/
576 
577 /**
578  *	__dev_get_by_name	- find a device by its name
579  *	@net: the applicable net namespace
580  *	@name: name to find
581  *
582  *	Find an interface by name. Must be called under RTNL semaphore
583  *	or @dev_base_lock. If the name is found a pointer to the device
584  *	is returned. If the name is not found then %NULL is returned. The
585  *	reference counters are not incremented so the caller must be
586  *	careful with locks.
587  */
588 
589 struct net_device *__dev_get_by_name(struct net *net, const char *name)
590 {
591 	struct hlist_node *p;
592 	struct net_device *dev;
593 	struct hlist_head *head = dev_name_hash(net, name);
594 
595 	hlist_for_each_entry(dev, p, head, name_hlist)
596 		if (!strncmp(dev->name, name, IFNAMSIZ))
597 			return dev;
598 
599 	return NULL;
600 }
601 EXPORT_SYMBOL(__dev_get_by_name);
602 
603 /**
604  *	dev_get_by_name_rcu	- find a device by its name
605  *	@net: the applicable net namespace
606  *	@name: name to find
607  *
608  *	Find an interface by name.
609  *	If the name is found a pointer to the device is returned.
610  * 	If the name is not found then %NULL is returned.
611  *	The reference counters are not incremented so the caller must be
612  *	careful with locks. The caller must hold RCU lock.
613  */
614 
615 struct net_device *dev_get_by_name_rcu(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_rcu(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_rcu);
628 
629 /**
630  *	dev_get_by_name		- find a device by its name
631  *	@net: the applicable net namespace
632  *	@name: name to find
633  *
634  *	Find an interface by name. This can be called from any
635  *	context and does its own locking. The returned handle has
636  *	the usage count incremented and the caller must use dev_put() to
637  *	release it when it is no longer needed. %NULL is returned if no
638  *	matching device is found.
639  */
640 
641 struct net_device *dev_get_by_name(struct net *net, const char *name)
642 {
643 	struct net_device *dev;
644 
645 	rcu_read_lock();
646 	dev = dev_get_by_name_rcu(net, name);
647 	if (dev)
648 		dev_hold(dev);
649 	rcu_read_unlock();
650 	return dev;
651 }
652 EXPORT_SYMBOL(dev_get_by_name);
653 
654 /**
655  *	__dev_get_by_index - find a device by its ifindex
656  *	@net: the applicable net namespace
657  *	@ifindex: index of device
658  *
659  *	Search for an interface by index. Returns %NULL if the device
660  *	is not found or a pointer to the device. The device has not
661  *	had its reference counter increased so the caller must be careful
662  *	about locking. The caller must hold either the RTNL semaphore
663  *	or @dev_base_lock.
664  */
665 
666 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
667 {
668 	struct hlist_node *p;
669 	struct net_device *dev;
670 	struct hlist_head *head = dev_index_hash(net, ifindex);
671 
672 	hlist_for_each_entry(dev, p, head, index_hlist)
673 		if (dev->ifindex == ifindex)
674 			return dev;
675 
676 	return NULL;
677 }
678 EXPORT_SYMBOL(__dev_get_by_index);
679 
680 /**
681  *	dev_get_by_index_rcu - 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 RCU lock.
689  */
690 
691 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
692 {
693 	struct hlist_node *p;
694 	struct net_device *dev;
695 	struct hlist_head *head = dev_index_hash(net, ifindex);
696 
697 	hlist_for_each_entry_rcu(dev, p, head, index_hlist)
698 		if (dev->ifindex == ifindex)
699 			return dev;
700 
701 	return NULL;
702 }
703 EXPORT_SYMBOL(dev_get_by_index_rcu);
704 
705 
706 /**
707  *	dev_get_by_index - 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 returned has
713  *	had a reference added and the pointer is safe until the user calls
714  *	dev_put to indicate they have finished with it.
715  */
716 
717 struct net_device *dev_get_by_index(struct net *net, int ifindex)
718 {
719 	struct net_device *dev;
720 
721 	rcu_read_lock();
722 	dev = dev_get_by_index_rcu(net, ifindex);
723 	if (dev)
724 		dev_hold(dev);
725 	rcu_read_unlock();
726 	return dev;
727 }
728 EXPORT_SYMBOL(dev_get_by_index);
729 
730 /**
731  *	dev_getbyhwaddr - find a device by its hardware address
732  *	@net: the applicable net namespace
733  *	@type: media type of device
734  *	@ha: hardware address
735  *
736  *	Search for an interface by MAC address. Returns NULL if the device
737  *	is not found or a pointer to the device. The caller must hold the
738  *	rtnl semaphore. The returned device has not had its ref count increased
739  *	and the caller must therefore be careful about locking
740  *
741  *	BUGS:
742  *	If the API was consistent this would be __dev_get_by_hwaddr
743  */
744 
745 struct net_device *dev_getbyhwaddr(struct net *net, unsigned short type, char *ha)
746 {
747 	struct net_device *dev;
748 
749 	ASSERT_RTNL();
750 
751 	for_each_netdev(net, dev)
752 		if (dev->type == type &&
753 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
754 			return dev;
755 
756 	return NULL;
757 }
758 EXPORT_SYMBOL(dev_getbyhwaddr);
759 
760 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
761 {
762 	struct net_device *dev;
763 
764 	ASSERT_RTNL();
765 	for_each_netdev(net, dev)
766 		if (dev->type == type)
767 			return dev;
768 
769 	return NULL;
770 }
771 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
772 
773 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
774 {
775 	struct net_device *dev;
776 
777 	rtnl_lock();
778 	dev = __dev_getfirstbyhwtype(net, type);
779 	if (dev)
780 		dev_hold(dev);
781 	rtnl_unlock();
782 	return dev;
783 }
784 EXPORT_SYMBOL(dev_getfirstbyhwtype);
785 
786 /**
787  *	dev_get_by_flags - find any device with given flags
788  *	@net: the applicable net namespace
789  *	@if_flags: IFF_* values
790  *	@mask: bitmask of bits in if_flags to check
791  *
792  *	Search for any interface with the given flags. Returns NULL if a device
793  *	is not found or a pointer to the device. The device returned has
794  *	had a reference added and the pointer is safe until the user calls
795  *	dev_put to indicate they have finished with it.
796  */
797 
798 struct net_device *dev_get_by_flags(struct net *net, unsigned short if_flags,
799 				    unsigned short mask)
800 {
801 	struct net_device *dev, *ret;
802 
803 	ret = NULL;
804 	rcu_read_lock();
805 	for_each_netdev_rcu(net, dev) {
806 		if (((dev->flags ^ if_flags) & mask) == 0) {
807 			dev_hold(dev);
808 			ret = dev;
809 			break;
810 		}
811 	}
812 	rcu_read_unlock();
813 	return ret;
814 }
815 EXPORT_SYMBOL(dev_get_by_flags);
816 
817 /**
818  *	dev_valid_name - check if name is okay for network device
819  *	@name: name string
820  *
821  *	Network device names need to be valid file names to
822  *	to allow sysfs to work.  We also disallow any kind of
823  *	whitespace.
824  */
825 int dev_valid_name(const char *name)
826 {
827 	if (*name == '\0')
828 		return 0;
829 	if (strlen(name) >= IFNAMSIZ)
830 		return 0;
831 	if (!strcmp(name, ".") || !strcmp(name, ".."))
832 		return 0;
833 
834 	while (*name) {
835 		if (*name == '/' || isspace(*name))
836 			return 0;
837 		name++;
838 	}
839 	return 1;
840 }
841 EXPORT_SYMBOL(dev_valid_name);
842 
843 /**
844  *	__dev_alloc_name - allocate a name for a device
845  *	@net: network namespace to allocate the device name in
846  *	@name: name format string
847  *	@buf:  scratch buffer and result name string
848  *
849  *	Passed a format string - eg "lt%d" it will try and find a suitable
850  *	id. It scans list of devices to build up a free map, then chooses
851  *	the first empty slot. The caller must hold the dev_base or rtnl lock
852  *	while allocating the name and adding the device in order to avoid
853  *	duplicates.
854  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
855  *	Returns the number of the unit assigned or a negative errno code.
856  */
857 
858 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
859 {
860 	int i = 0;
861 	const char *p;
862 	const int max_netdevices = 8*PAGE_SIZE;
863 	unsigned long *inuse;
864 	struct net_device *d;
865 
866 	p = strnchr(name, IFNAMSIZ-1, '%');
867 	if (p) {
868 		/*
869 		 * Verify the string as this thing may have come from
870 		 * the user.  There must be either one "%d" and no other "%"
871 		 * characters.
872 		 */
873 		if (p[1] != 'd' || strchr(p + 2, '%'))
874 			return -EINVAL;
875 
876 		/* Use one page as a bit array of possible slots */
877 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
878 		if (!inuse)
879 			return -ENOMEM;
880 
881 		for_each_netdev(net, d) {
882 			if (!sscanf(d->name, name, &i))
883 				continue;
884 			if (i < 0 || i >= max_netdevices)
885 				continue;
886 
887 			/*  avoid cases where sscanf is not exact inverse of printf */
888 			snprintf(buf, IFNAMSIZ, name, i);
889 			if (!strncmp(buf, d->name, IFNAMSIZ))
890 				set_bit(i, inuse);
891 		}
892 
893 		i = find_first_zero_bit(inuse, max_netdevices);
894 		free_page((unsigned long) inuse);
895 	}
896 
897 	if (buf != name)
898 		snprintf(buf, IFNAMSIZ, name, i);
899 	if (!__dev_get_by_name(net, buf))
900 		return i;
901 
902 	/* It is possible to run out of possible slots
903 	 * when the name is long and there isn't enough space left
904 	 * for the digits, or if all bits are used.
905 	 */
906 	return -ENFILE;
907 }
908 
909 /**
910  *	dev_alloc_name - allocate a name for a device
911  *	@dev: device
912  *	@name: name format string
913  *
914  *	Passed a format string - eg "lt%d" it will try and find a suitable
915  *	id. It scans list of devices to build up a free map, then chooses
916  *	the first empty slot. The caller must hold the dev_base or rtnl lock
917  *	while allocating the name and adding the device in order to avoid
918  *	duplicates.
919  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
920  *	Returns the number of the unit assigned or a negative errno code.
921  */
922 
923 int dev_alloc_name(struct net_device *dev, const char *name)
924 {
925 	char buf[IFNAMSIZ];
926 	struct net *net;
927 	int ret;
928 
929 	BUG_ON(!dev_net(dev));
930 	net = dev_net(dev);
931 	ret = __dev_alloc_name(net, name, buf);
932 	if (ret >= 0)
933 		strlcpy(dev->name, buf, IFNAMSIZ);
934 	return ret;
935 }
936 EXPORT_SYMBOL(dev_alloc_name);
937 
938 static int dev_get_valid_name(struct net *net, const char *name, char *buf,
939 			      bool fmt)
940 {
941 	if (!dev_valid_name(name))
942 		return -EINVAL;
943 
944 	if (fmt && strchr(name, '%'))
945 		return __dev_alloc_name(net, name, buf);
946 	else if (__dev_get_by_name(net, name))
947 		return -EEXIST;
948 	else if (buf != name)
949 		strlcpy(buf, name, IFNAMSIZ);
950 
951 	return 0;
952 }
953 
954 /**
955  *	dev_change_name - change name of a device
956  *	@dev: device
957  *	@newname: name (or format string) must be at least IFNAMSIZ
958  *
959  *	Change name of a device, can pass format strings "eth%d".
960  *	for wildcarding.
961  */
962 int dev_change_name(struct net_device *dev, const char *newname)
963 {
964 	char oldname[IFNAMSIZ];
965 	int err = 0;
966 	int ret;
967 	struct net *net;
968 
969 	ASSERT_RTNL();
970 	BUG_ON(!dev_net(dev));
971 
972 	net = dev_net(dev);
973 	if (dev->flags & IFF_UP)
974 		return -EBUSY;
975 
976 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
977 		return 0;
978 
979 	memcpy(oldname, dev->name, IFNAMSIZ);
980 
981 	err = dev_get_valid_name(net, newname, dev->name, 1);
982 	if (err < 0)
983 		return err;
984 
985 rollback:
986 	/* For now only devices in the initial network namespace
987 	 * are in sysfs.
988 	 */
989 	if (net_eq(net, &init_net)) {
990 		ret = device_rename(&dev->dev, dev->name);
991 		if (ret) {
992 			memcpy(dev->name, oldname, IFNAMSIZ);
993 			return ret;
994 		}
995 	}
996 
997 	write_lock_bh(&dev_base_lock);
998 	hlist_del(&dev->name_hlist);
999 	write_unlock_bh(&dev_base_lock);
1000 
1001 	synchronize_rcu();
1002 
1003 	write_lock_bh(&dev_base_lock);
1004 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1005 	write_unlock_bh(&dev_base_lock);
1006 
1007 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1008 	ret = notifier_to_errno(ret);
1009 
1010 	if (ret) {
1011 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1012 		if (err >= 0) {
1013 			err = ret;
1014 			memcpy(dev->name, oldname, IFNAMSIZ);
1015 			goto rollback;
1016 		} else {
1017 			printk(KERN_ERR
1018 			       "%s: name change rollback failed: %d.\n",
1019 			       dev->name, ret);
1020 		}
1021 	}
1022 
1023 	return err;
1024 }
1025 
1026 /**
1027  *	dev_set_alias - change ifalias of a device
1028  *	@dev: device
1029  *	@alias: name up to IFALIASZ
1030  *	@len: limit of bytes to copy from info
1031  *
1032  *	Set ifalias for a device,
1033  */
1034 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1035 {
1036 	ASSERT_RTNL();
1037 
1038 	if (len >= IFALIASZ)
1039 		return -EINVAL;
1040 
1041 	if (!len) {
1042 		if (dev->ifalias) {
1043 			kfree(dev->ifalias);
1044 			dev->ifalias = NULL;
1045 		}
1046 		return 0;
1047 	}
1048 
1049 	dev->ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1050 	if (!dev->ifalias)
1051 		return -ENOMEM;
1052 
1053 	strlcpy(dev->ifalias, alias, len+1);
1054 	return len;
1055 }
1056 
1057 
1058 /**
1059  *	netdev_features_change - device changes features
1060  *	@dev: device to cause notification
1061  *
1062  *	Called to indicate a device has changed features.
1063  */
1064 void netdev_features_change(struct net_device *dev)
1065 {
1066 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1067 }
1068 EXPORT_SYMBOL(netdev_features_change);
1069 
1070 /**
1071  *	netdev_state_change - device changes state
1072  *	@dev: device to cause notification
1073  *
1074  *	Called to indicate a device has changed state. This function calls
1075  *	the notifier chains for netdev_chain and sends a NEWLINK message
1076  *	to the routing socket.
1077  */
1078 void netdev_state_change(struct net_device *dev)
1079 {
1080 	if (dev->flags & IFF_UP) {
1081 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
1082 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1083 	}
1084 }
1085 EXPORT_SYMBOL(netdev_state_change);
1086 
1087 void netdev_bonding_change(struct net_device *dev, unsigned long event)
1088 {
1089 	call_netdevice_notifiers(event, dev);
1090 }
1091 EXPORT_SYMBOL(netdev_bonding_change);
1092 
1093 /**
1094  *	dev_load 	- load a network module
1095  *	@net: the applicable net namespace
1096  *	@name: name of interface
1097  *
1098  *	If a network interface is not present and the process has suitable
1099  *	privileges this function loads the module. If module loading is not
1100  *	available in this kernel then it becomes a nop.
1101  */
1102 
1103 void dev_load(struct net *net, const char *name)
1104 {
1105 	struct net_device *dev;
1106 
1107 	rcu_read_lock();
1108 	dev = dev_get_by_name_rcu(net, name);
1109 	rcu_read_unlock();
1110 
1111 	if (!dev && capable(CAP_NET_ADMIN))
1112 		request_module("%s", name);
1113 }
1114 EXPORT_SYMBOL(dev_load);
1115 
1116 /**
1117  *	dev_open	- prepare an interface for use.
1118  *	@dev:	device to open
1119  *
1120  *	Takes a device from down to up state. The device's private open
1121  *	function is invoked and then the multicast lists are loaded. Finally
1122  *	the device is moved into the up state and a %NETDEV_UP message is
1123  *	sent to the netdev notifier chain.
1124  *
1125  *	Calling this function on an active interface is a nop. On a failure
1126  *	a negative errno code is returned.
1127  */
1128 int dev_open(struct net_device *dev)
1129 {
1130 	const struct net_device_ops *ops = dev->netdev_ops;
1131 	int ret;
1132 
1133 	ASSERT_RTNL();
1134 
1135 	/*
1136 	 *	Is it already up?
1137 	 */
1138 
1139 	if (dev->flags & IFF_UP)
1140 		return 0;
1141 
1142 	/*
1143 	 *	Is it even present?
1144 	 */
1145 	if (!netif_device_present(dev))
1146 		return -ENODEV;
1147 
1148 	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1149 	ret = notifier_to_errno(ret);
1150 	if (ret)
1151 		return ret;
1152 
1153 	/*
1154 	 *	Call device private open method
1155 	 */
1156 	set_bit(__LINK_STATE_START, &dev->state);
1157 
1158 	if (ops->ndo_validate_addr)
1159 		ret = ops->ndo_validate_addr(dev);
1160 
1161 	if (!ret && ops->ndo_open)
1162 		ret = ops->ndo_open(dev);
1163 
1164 	/*
1165 	 *	If it went open OK then:
1166 	 */
1167 
1168 	if (ret)
1169 		clear_bit(__LINK_STATE_START, &dev->state);
1170 	else {
1171 		/*
1172 		 *	Set the flags.
1173 		 */
1174 		dev->flags |= IFF_UP;
1175 
1176 		/*
1177 		 *	Enable NET_DMA
1178 		 */
1179 		net_dmaengine_get();
1180 
1181 		/*
1182 		 *	Initialize multicasting status
1183 		 */
1184 		dev_set_rx_mode(dev);
1185 
1186 		/*
1187 		 *	Wakeup transmit queue engine
1188 		 */
1189 		dev_activate(dev);
1190 
1191 		/*
1192 		 *	... and announce new interface.
1193 		 */
1194 		call_netdevice_notifiers(NETDEV_UP, dev);
1195 	}
1196 
1197 	return ret;
1198 }
1199 EXPORT_SYMBOL(dev_open);
1200 
1201 /**
1202  *	dev_close - shutdown an interface.
1203  *	@dev: device to shutdown
1204  *
1205  *	This function moves an active device into down state. A
1206  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1207  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1208  *	chain.
1209  */
1210 int dev_close(struct net_device *dev)
1211 {
1212 	const struct net_device_ops *ops = dev->netdev_ops;
1213 	ASSERT_RTNL();
1214 
1215 	might_sleep();
1216 
1217 	if (!(dev->flags & IFF_UP))
1218 		return 0;
1219 
1220 	/*
1221 	 *	Tell people we are going down, so that they can
1222 	 *	prepare to death, when device is still operating.
1223 	 */
1224 	call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1225 
1226 	clear_bit(__LINK_STATE_START, &dev->state);
1227 
1228 	/* Synchronize to scheduled poll. We cannot touch poll list,
1229 	 * it can be even on different cpu. So just clear netif_running().
1230 	 *
1231 	 * dev->stop() will invoke napi_disable() on all of it's
1232 	 * napi_struct instances on this device.
1233 	 */
1234 	smp_mb__after_clear_bit(); /* Commit netif_running(). */
1235 
1236 	dev_deactivate(dev);
1237 
1238 	/*
1239 	 *	Call the device specific close. This cannot fail.
1240 	 *	Only if device is UP
1241 	 *
1242 	 *	We allow it to be called even after a DETACH hot-plug
1243 	 *	event.
1244 	 */
1245 	if (ops->ndo_stop)
1246 		ops->ndo_stop(dev);
1247 
1248 	/*
1249 	 *	Device is now down.
1250 	 */
1251 
1252 	dev->flags &= ~IFF_UP;
1253 
1254 	/*
1255 	 * Tell people we are down
1256 	 */
1257 	call_netdevice_notifiers(NETDEV_DOWN, dev);
1258 
1259 	/*
1260 	 *	Shutdown NET_DMA
1261 	 */
1262 	net_dmaengine_put();
1263 
1264 	return 0;
1265 }
1266 EXPORT_SYMBOL(dev_close);
1267 
1268 
1269 /**
1270  *	dev_disable_lro - disable Large Receive Offload on a device
1271  *	@dev: device
1272  *
1273  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1274  *	called under RTNL.  This is needed if received packets may be
1275  *	forwarded to another interface.
1276  */
1277 void dev_disable_lro(struct net_device *dev)
1278 {
1279 	if (dev->ethtool_ops && dev->ethtool_ops->get_flags &&
1280 	    dev->ethtool_ops->set_flags) {
1281 		u32 flags = dev->ethtool_ops->get_flags(dev);
1282 		if (flags & ETH_FLAG_LRO) {
1283 			flags &= ~ETH_FLAG_LRO;
1284 			dev->ethtool_ops->set_flags(dev, flags);
1285 		}
1286 	}
1287 	WARN_ON(dev->features & NETIF_F_LRO);
1288 }
1289 EXPORT_SYMBOL(dev_disable_lro);
1290 
1291 
1292 static int dev_boot_phase = 1;
1293 
1294 /*
1295  *	Device change register/unregister. These are not inline or static
1296  *	as we export them to the world.
1297  */
1298 
1299 /**
1300  *	register_netdevice_notifier - register a network notifier block
1301  *	@nb: notifier
1302  *
1303  *	Register a notifier to be called when network device events occur.
1304  *	The notifier passed is linked into the kernel structures and must
1305  *	not be reused until it has been unregistered. A negative errno code
1306  *	is returned on a failure.
1307  *
1308  * 	When registered all registration and up events are replayed
1309  *	to the new notifier to allow device to have a race free
1310  *	view of the network device list.
1311  */
1312 
1313 int register_netdevice_notifier(struct notifier_block *nb)
1314 {
1315 	struct net_device *dev;
1316 	struct net_device *last;
1317 	struct net *net;
1318 	int err;
1319 
1320 	rtnl_lock();
1321 	err = raw_notifier_chain_register(&netdev_chain, nb);
1322 	if (err)
1323 		goto unlock;
1324 	if (dev_boot_phase)
1325 		goto unlock;
1326 	for_each_net(net) {
1327 		for_each_netdev(net, dev) {
1328 			err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1329 			err = notifier_to_errno(err);
1330 			if (err)
1331 				goto rollback;
1332 
1333 			if (!(dev->flags & IFF_UP))
1334 				continue;
1335 
1336 			nb->notifier_call(nb, NETDEV_UP, dev);
1337 		}
1338 	}
1339 
1340 unlock:
1341 	rtnl_unlock();
1342 	return err;
1343 
1344 rollback:
1345 	last = dev;
1346 	for_each_net(net) {
1347 		for_each_netdev(net, dev) {
1348 			if (dev == last)
1349 				break;
1350 
1351 			if (dev->flags & IFF_UP) {
1352 				nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1353 				nb->notifier_call(nb, NETDEV_DOWN, dev);
1354 			}
1355 			nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1356 			nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
1357 		}
1358 	}
1359 
1360 	raw_notifier_chain_unregister(&netdev_chain, nb);
1361 	goto unlock;
1362 }
1363 EXPORT_SYMBOL(register_netdevice_notifier);
1364 
1365 /**
1366  *	unregister_netdevice_notifier - unregister a network notifier block
1367  *	@nb: notifier
1368  *
1369  *	Unregister a notifier previously registered by
1370  *	register_netdevice_notifier(). The notifier is unlinked into the
1371  *	kernel structures and may then be reused. A negative errno code
1372  *	is returned on a failure.
1373  */
1374 
1375 int unregister_netdevice_notifier(struct notifier_block *nb)
1376 {
1377 	int err;
1378 
1379 	rtnl_lock();
1380 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1381 	rtnl_unlock();
1382 	return err;
1383 }
1384 EXPORT_SYMBOL(unregister_netdevice_notifier);
1385 
1386 /**
1387  *	call_netdevice_notifiers - call all network notifier blocks
1388  *      @val: value passed unmodified to notifier function
1389  *      @dev: net_device pointer passed unmodified to notifier function
1390  *
1391  *	Call all network notifier blocks.  Parameters and return value
1392  *	are as for raw_notifier_call_chain().
1393  */
1394 
1395 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1396 {
1397 	return raw_notifier_call_chain(&netdev_chain, val, dev);
1398 }
1399 
1400 /* When > 0 there are consumers of rx skb time stamps */
1401 static atomic_t netstamp_needed = ATOMIC_INIT(0);
1402 
1403 void net_enable_timestamp(void)
1404 {
1405 	atomic_inc(&netstamp_needed);
1406 }
1407 EXPORT_SYMBOL(net_enable_timestamp);
1408 
1409 void net_disable_timestamp(void)
1410 {
1411 	atomic_dec(&netstamp_needed);
1412 }
1413 EXPORT_SYMBOL(net_disable_timestamp);
1414 
1415 static inline void net_timestamp(struct sk_buff *skb)
1416 {
1417 	if (atomic_read(&netstamp_needed))
1418 		__net_timestamp(skb);
1419 	else
1420 		skb->tstamp.tv64 = 0;
1421 }
1422 
1423 /**
1424  * dev_forward_skb - loopback an skb to another netif
1425  *
1426  * @dev: destination network device
1427  * @skb: buffer to forward
1428  *
1429  * return values:
1430  *	NET_RX_SUCCESS	(no congestion)
1431  *	NET_RX_DROP     (packet was dropped)
1432  *
1433  * dev_forward_skb can be used for injecting an skb from the
1434  * start_xmit function of one device into the receive queue
1435  * of another device.
1436  *
1437  * The receiving device may be in another namespace, so
1438  * we have to clear all information in the skb that could
1439  * impact namespace isolation.
1440  */
1441 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1442 {
1443 	skb_orphan(skb);
1444 
1445 	if (!(dev->flags & IFF_UP))
1446 		return NET_RX_DROP;
1447 
1448 	if (skb->len > (dev->mtu + dev->hard_header_len))
1449 		return NET_RX_DROP;
1450 
1451 	skb_dst_drop(skb);
1452 	skb->tstamp.tv64 = 0;
1453 	skb->pkt_type = PACKET_HOST;
1454 	skb->protocol = eth_type_trans(skb, dev);
1455 	skb->mark = 0;
1456 	secpath_reset(skb);
1457 	nf_reset(skb);
1458 	return netif_rx(skb);
1459 }
1460 EXPORT_SYMBOL_GPL(dev_forward_skb);
1461 
1462 /*
1463  *	Support routine. Sends outgoing frames to any network
1464  *	taps currently in use.
1465  */
1466 
1467 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1468 {
1469 	struct packet_type *ptype;
1470 
1471 #ifdef CONFIG_NET_CLS_ACT
1472 	if (!(skb->tstamp.tv64 && (G_TC_FROM(skb->tc_verd) & AT_INGRESS)))
1473 		net_timestamp(skb);
1474 #else
1475 	net_timestamp(skb);
1476 #endif
1477 
1478 	rcu_read_lock();
1479 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1480 		/* Never send packets back to the socket
1481 		 * they originated from - MvS (miquels@drinkel.ow.org)
1482 		 */
1483 		if ((ptype->dev == dev || !ptype->dev) &&
1484 		    (ptype->af_packet_priv == NULL ||
1485 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1486 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1487 			if (!skb2)
1488 				break;
1489 
1490 			/* skb->nh should be correctly
1491 			   set by sender, so that the second statement is
1492 			   just protection against buggy protocols.
1493 			 */
1494 			skb_reset_mac_header(skb2);
1495 
1496 			if (skb_network_header(skb2) < skb2->data ||
1497 			    skb2->network_header > skb2->tail) {
1498 				if (net_ratelimit())
1499 					printk(KERN_CRIT "protocol %04x is "
1500 					       "buggy, dev %s\n",
1501 					       skb2->protocol, dev->name);
1502 				skb_reset_network_header(skb2);
1503 			}
1504 
1505 			skb2->transport_header = skb2->network_header;
1506 			skb2->pkt_type = PACKET_OUTGOING;
1507 			ptype->func(skb2, skb->dev, ptype, skb->dev);
1508 		}
1509 	}
1510 	rcu_read_unlock();
1511 }
1512 
1513 
1514 static inline void __netif_reschedule(struct Qdisc *q)
1515 {
1516 	struct softnet_data *sd;
1517 	unsigned long flags;
1518 
1519 	local_irq_save(flags);
1520 	sd = &__get_cpu_var(softnet_data);
1521 	q->next_sched = sd->output_queue;
1522 	sd->output_queue = q;
1523 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
1524 	local_irq_restore(flags);
1525 }
1526 
1527 void __netif_schedule(struct Qdisc *q)
1528 {
1529 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
1530 		__netif_reschedule(q);
1531 }
1532 EXPORT_SYMBOL(__netif_schedule);
1533 
1534 void dev_kfree_skb_irq(struct sk_buff *skb)
1535 {
1536 	if (atomic_dec_and_test(&skb->users)) {
1537 		struct softnet_data *sd;
1538 		unsigned long flags;
1539 
1540 		local_irq_save(flags);
1541 		sd = &__get_cpu_var(softnet_data);
1542 		skb->next = sd->completion_queue;
1543 		sd->completion_queue = skb;
1544 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
1545 		local_irq_restore(flags);
1546 	}
1547 }
1548 EXPORT_SYMBOL(dev_kfree_skb_irq);
1549 
1550 void dev_kfree_skb_any(struct sk_buff *skb)
1551 {
1552 	if (in_irq() || irqs_disabled())
1553 		dev_kfree_skb_irq(skb);
1554 	else
1555 		dev_kfree_skb(skb);
1556 }
1557 EXPORT_SYMBOL(dev_kfree_skb_any);
1558 
1559 
1560 /**
1561  * netif_device_detach - mark device as removed
1562  * @dev: network device
1563  *
1564  * Mark device as removed from system and therefore no longer available.
1565  */
1566 void netif_device_detach(struct net_device *dev)
1567 {
1568 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
1569 	    netif_running(dev)) {
1570 		netif_tx_stop_all_queues(dev);
1571 	}
1572 }
1573 EXPORT_SYMBOL(netif_device_detach);
1574 
1575 /**
1576  * netif_device_attach - mark device as attached
1577  * @dev: network device
1578  *
1579  * Mark device as attached from system and restart if needed.
1580  */
1581 void netif_device_attach(struct net_device *dev)
1582 {
1583 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
1584 	    netif_running(dev)) {
1585 		netif_tx_wake_all_queues(dev);
1586 		__netdev_watchdog_up(dev);
1587 	}
1588 }
1589 EXPORT_SYMBOL(netif_device_attach);
1590 
1591 static bool can_checksum_protocol(unsigned long features, __be16 protocol)
1592 {
1593 	return ((features & NETIF_F_GEN_CSUM) ||
1594 		((features & NETIF_F_IP_CSUM) &&
1595 		 protocol == htons(ETH_P_IP)) ||
1596 		((features & NETIF_F_IPV6_CSUM) &&
1597 		 protocol == htons(ETH_P_IPV6)) ||
1598 		((features & NETIF_F_FCOE_CRC) &&
1599 		 protocol == htons(ETH_P_FCOE)));
1600 }
1601 
1602 static bool dev_can_checksum(struct net_device *dev, struct sk_buff *skb)
1603 {
1604 	if (can_checksum_protocol(dev->features, skb->protocol))
1605 		return true;
1606 
1607 	if (skb->protocol == htons(ETH_P_8021Q)) {
1608 		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
1609 		if (can_checksum_protocol(dev->features & dev->vlan_features,
1610 					  veh->h_vlan_encapsulated_proto))
1611 			return true;
1612 	}
1613 
1614 	return false;
1615 }
1616 
1617 /*
1618  * Invalidate hardware checksum when packet is to be mangled, and
1619  * complete checksum manually on outgoing path.
1620  */
1621 int skb_checksum_help(struct sk_buff *skb)
1622 {
1623 	__wsum csum;
1624 	int ret = 0, offset;
1625 
1626 	if (skb->ip_summed == CHECKSUM_COMPLETE)
1627 		goto out_set_summed;
1628 
1629 	if (unlikely(skb_shinfo(skb)->gso_size)) {
1630 		/* Let GSO fix up the checksum. */
1631 		goto out_set_summed;
1632 	}
1633 
1634 	offset = skb->csum_start - skb_headroom(skb);
1635 	BUG_ON(offset >= skb_headlen(skb));
1636 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
1637 
1638 	offset += skb->csum_offset;
1639 	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
1640 
1641 	if (skb_cloned(skb) &&
1642 	    !skb_clone_writable(skb, offset + sizeof(__sum16))) {
1643 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1644 		if (ret)
1645 			goto out;
1646 	}
1647 
1648 	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
1649 out_set_summed:
1650 	skb->ip_summed = CHECKSUM_NONE;
1651 out:
1652 	return ret;
1653 }
1654 EXPORT_SYMBOL(skb_checksum_help);
1655 
1656 /**
1657  *	skb_gso_segment - Perform segmentation on skb.
1658  *	@skb: buffer to segment
1659  *	@features: features for the output path (see dev->features)
1660  *
1661  *	This function segments the given skb and returns a list of segments.
1662  *
1663  *	It may return NULL if the skb requires no segmentation.  This is
1664  *	only possible when GSO is used for verifying header integrity.
1665  */
1666 struct sk_buff *skb_gso_segment(struct sk_buff *skb, int features)
1667 {
1668 	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
1669 	struct packet_type *ptype;
1670 	__be16 type = skb->protocol;
1671 	int err;
1672 
1673 	skb_reset_mac_header(skb);
1674 	skb->mac_len = skb->network_header - skb->mac_header;
1675 	__skb_pull(skb, skb->mac_len);
1676 
1677 	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1678 		struct net_device *dev = skb->dev;
1679 		struct ethtool_drvinfo info = {};
1680 
1681 		if (dev && dev->ethtool_ops && dev->ethtool_ops->get_drvinfo)
1682 			dev->ethtool_ops->get_drvinfo(dev, &info);
1683 
1684 		WARN(1, "%s: caps=(0x%lx, 0x%lx) len=%d data_len=%d "
1685 			"ip_summed=%d",
1686 		     info.driver, dev ? dev->features : 0L,
1687 		     skb->sk ? skb->sk->sk_route_caps : 0L,
1688 		     skb->len, skb->data_len, skb->ip_summed);
1689 
1690 		if (skb_header_cloned(skb) &&
1691 		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
1692 			return ERR_PTR(err);
1693 	}
1694 
1695 	rcu_read_lock();
1696 	list_for_each_entry_rcu(ptype,
1697 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
1698 		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
1699 			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1700 				err = ptype->gso_send_check(skb);
1701 				segs = ERR_PTR(err);
1702 				if (err || skb_gso_ok(skb, features))
1703 					break;
1704 				__skb_push(skb, (skb->data -
1705 						 skb_network_header(skb)));
1706 			}
1707 			segs = ptype->gso_segment(skb, features);
1708 			break;
1709 		}
1710 	}
1711 	rcu_read_unlock();
1712 
1713 	__skb_push(skb, skb->data - skb_mac_header(skb));
1714 
1715 	return segs;
1716 }
1717 EXPORT_SYMBOL(skb_gso_segment);
1718 
1719 /* Take action when hardware reception checksum errors are detected. */
1720 #ifdef CONFIG_BUG
1721 void netdev_rx_csum_fault(struct net_device *dev)
1722 {
1723 	if (net_ratelimit()) {
1724 		printk(KERN_ERR "%s: hw csum failure.\n",
1725 			dev ? dev->name : "<unknown>");
1726 		dump_stack();
1727 	}
1728 }
1729 EXPORT_SYMBOL(netdev_rx_csum_fault);
1730 #endif
1731 
1732 /* Actually, we should eliminate this check as soon as we know, that:
1733  * 1. IOMMU is present and allows to map all the memory.
1734  * 2. No high memory really exists on this machine.
1735  */
1736 
1737 static inline int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1738 {
1739 #ifdef CONFIG_HIGHMEM
1740 	int i;
1741 
1742 	if (dev->features & NETIF_F_HIGHDMA)
1743 		return 0;
1744 
1745 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1746 		if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1747 			return 1;
1748 
1749 #endif
1750 	return 0;
1751 }
1752 
1753 struct dev_gso_cb {
1754 	void (*destructor)(struct sk_buff *skb);
1755 };
1756 
1757 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
1758 
1759 static void dev_gso_skb_destructor(struct sk_buff *skb)
1760 {
1761 	struct dev_gso_cb *cb;
1762 
1763 	do {
1764 		struct sk_buff *nskb = skb->next;
1765 
1766 		skb->next = nskb->next;
1767 		nskb->next = NULL;
1768 		kfree_skb(nskb);
1769 	} while (skb->next);
1770 
1771 	cb = DEV_GSO_CB(skb);
1772 	if (cb->destructor)
1773 		cb->destructor(skb);
1774 }
1775 
1776 /**
1777  *	dev_gso_segment - Perform emulated hardware segmentation on skb.
1778  *	@skb: buffer to segment
1779  *
1780  *	This function segments the given skb and stores the list of segments
1781  *	in skb->next.
1782  */
1783 static int dev_gso_segment(struct sk_buff *skb)
1784 {
1785 	struct net_device *dev = skb->dev;
1786 	struct sk_buff *segs;
1787 	int features = dev->features & ~(illegal_highdma(dev, skb) ?
1788 					 NETIF_F_SG : 0);
1789 
1790 	segs = skb_gso_segment(skb, features);
1791 
1792 	/* Verifying header integrity only. */
1793 	if (!segs)
1794 		return 0;
1795 
1796 	if (IS_ERR(segs))
1797 		return PTR_ERR(segs);
1798 
1799 	skb->next = segs;
1800 	DEV_GSO_CB(skb)->destructor = skb->destructor;
1801 	skb->destructor = dev_gso_skb_destructor;
1802 
1803 	return 0;
1804 }
1805 
1806 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
1807 			struct netdev_queue *txq)
1808 {
1809 	const struct net_device_ops *ops = dev->netdev_ops;
1810 	int rc = NETDEV_TX_OK;
1811 
1812 	if (likely(!skb->next)) {
1813 		if (!list_empty(&ptype_all))
1814 			dev_queue_xmit_nit(skb, dev);
1815 
1816 		if (netif_needs_gso(dev, skb)) {
1817 			if (unlikely(dev_gso_segment(skb)))
1818 				goto out_kfree_skb;
1819 			if (skb->next)
1820 				goto gso;
1821 		}
1822 
1823 		/*
1824 		 * If device doesnt need skb->dst, release it right now while
1825 		 * its hot in this cpu cache
1826 		 */
1827 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
1828 			skb_dst_drop(skb);
1829 
1830 		rc = ops->ndo_start_xmit(skb, dev);
1831 		if (rc == NETDEV_TX_OK)
1832 			txq_trans_update(txq);
1833 		/*
1834 		 * TODO: if skb_orphan() was called by
1835 		 * dev->hard_start_xmit() (for example, the unmodified
1836 		 * igb driver does that; bnx2 doesn't), then
1837 		 * skb_tx_software_timestamp() will be unable to send
1838 		 * back the time stamp.
1839 		 *
1840 		 * How can this be prevented? Always create another
1841 		 * reference to the socket before calling
1842 		 * dev->hard_start_xmit()? Prevent that skb_orphan()
1843 		 * does anything in dev->hard_start_xmit() by clearing
1844 		 * the skb destructor before the call and restoring it
1845 		 * afterwards, then doing the skb_orphan() ourselves?
1846 		 */
1847 		return rc;
1848 	}
1849 
1850 gso:
1851 	do {
1852 		struct sk_buff *nskb = skb->next;
1853 
1854 		skb->next = nskb->next;
1855 		nskb->next = NULL;
1856 
1857 		/*
1858 		 * If device doesnt need nskb->dst, release it right now while
1859 		 * its hot in this cpu cache
1860 		 */
1861 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
1862 			skb_dst_drop(nskb);
1863 
1864 		rc = ops->ndo_start_xmit(nskb, dev);
1865 		if (unlikely(rc != NETDEV_TX_OK)) {
1866 			if (rc & ~NETDEV_TX_MASK)
1867 				goto out_kfree_gso_skb;
1868 			nskb->next = skb->next;
1869 			skb->next = nskb;
1870 			return rc;
1871 		}
1872 		txq_trans_update(txq);
1873 		if (unlikely(netif_tx_queue_stopped(txq) && skb->next))
1874 			return NETDEV_TX_BUSY;
1875 	} while (skb->next);
1876 
1877 out_kfree_gso_skb:
1878 	if (likely(skb->next == NULL))
1879 		skb->destructor = DEV_GSO_CB(skb)->destructor;
1880 out_kfree_skb:
1881 	kfree_skb(skb);
1882 	return rc;
1883 }
1884 
1885 static u32 skb_tx_hashrnd;
1886 
1887 u16 skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb)
1888 {
1889 	u32 hash;
1890 
1891 	if (skb_rx_queue_recorded(skb)) {
1892 		hash = skb_get_rx_queue(skb);
1893 		while (unlikely(hash >= dev->real_num_tx_queues))
1894 			hash -= dev->real_num_tx_queues;
1895 		return hash;
1896 	}
1897 
1898 	if (skb->sk && skb->sk->sk_hash)
1899 		hash = skb->sk->sk_hash;
1900 	else
1901 		hash = skb->protocol;
1902 
1903 	hash = jhash_1word(hash, skb_tx_hashrnd);
1904 
1905 	return (u16) (((u64) hash * dev->real_num_tx_queues) >> 32);
1906 }
1907 EXPORT_SYMBOL(skb_tx_hash);
1908 
1909 static inline u16 dev_cap_txqueue(struct net_device *dev, u16 queue_index)
1910 {
1911 	if (unlikely(queue_index >= dev->real_num_tx_queues)) {
1912 		if (net_ratelimit()) {
1913 			WARN(1, "%s selects TX queue %d, but "
1914 			     "real number of TX queues is %d\n",
1915 			     dev->name, queue_index,
1916 			     dev->real_num_tx_queues);
1917 		}
1918 		return 0;
1919 	}
1920 	return queue_index;
1921 }
1922 
1923 static struct netdev_queue *dev_pick_tx(struct net_device *dev,
1924 					struct sk_buff *skb)
1925 {
1926 	u16 queue_index;
1927 	struct sock *sk = skb->sk;
1928 
1929 	if (sk_tx_queue_recorded(sk)) {
1930 		queue_index = sk_tx_queue_get(sk);
1931 	} else {
1932 		const struct net_device_ops *ops = dev->netdev_ops;
1933 
1934 		if (ops->ndo_select_queue) {
1935 			queue_index = ops->ndo_select_queue(dev, skb);
1936 			queue_index = dev_cap_txqueue(dev, queue_index);
1937 		} else {
1938 			queue_index = 0;
1939 			if (dev->real_num_tx_queues > 1)
1940 				queue_index = skb_tx_hash(dev, skb);
1941 
1942 			if (sk && sk->sk_dst_cache)
1943 				sk_tx_queue_set(sk, queue_index);
1944 		}
1945 	}
1946 
1947 	skb_set_queue_mapping(skb, queue_index);
1948 	return netdev_get_tx_queue(dev, queue_index);
1949 }
1950 
1951 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
1952 				 struct net_device *dev,
1953 				 struct netdev_queue *txq)
1954 {
1955 	spinlock_t *root_lock = qdisc_lock(q);
1956 	int rc;
1957 
1958 	spin_lock(root_lock);
1959 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
1960 		kfree_skb(skb);
1961 		rc = NET_XMIT_DROP;
1962 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
1963 		   !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) {
1964 		/*
1965 		 * This is a work-conserving queue; there are no old skbs
1966 		 * waiting to be sent out; and the qdisc is not running -
1967 		 * xmit the skb directly.
1968 		 */
1969 		__qdisc_update_bstats(q, skb->len);
1970 		if (sch_direct_xmit(skb, q, dev, txq, root_lock))
1971 			__qdisc_run(q);
1972 		else
1973 			clear_bit(__QDISC_STATE_RUNNING, &q->state);
1974 
1975 		rc = NET_XMIT_SUCCESS;
1976 	} else {
1977 		rc = qdisc_enqueue_root(skb, q);
1978 		qdisc_run(q);
1979 	}
1980 	spin_unlock(root_lock);
1981 
1982 	return rc;
1983 }
1984 
1985 /**
1986  *	dev_queue_xmit - transmit a buffer
1987  *	@skb: buffer to transmit
1988  *
1989  *	Queue a buffer for transmission to a network device. The caller must
1990  *	have set the device and priority and built the buffer before calling
1991  *	this function. The function can be called from an interrupt.
1992  *
1993  *	A negative errno code is returned on a failure. A success does not
1994  *	guarantee the frame will be transmitted as it may be dropped due
1995  *	to congestion or traffic shaping.
1996  *
1997  * -----------------------------------------------------------------------------------
1998  *      I notice this method can also return errors from the queue disciplines,
1999  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
2000  *      be positive.
2001  *
2002  *      Regardless of the return value, the skb is consumed, so it is currently
2003  *      difficult to retry a send to this method.  (You can bump the ref count
2004  *      before sending to hold a reference for retry if you are careful.)
2005  *
2006  *      When calling this method, interrupts MUST be enabled.  This is because
2007  *      the BH enable code must have IRQs enabled so that it will not deadlock.
2008  *          --BLG
2009  */
2010 int dev_queue_xmit(struct sk_buff *skb)
2011 {
2012 	struct net_device *dev = skb->dev;
2013 	struct netdev_queue *txq;
2014 	struct Qdisc *q;
2015 	int rc = -ENOMEM;
2016 
2017 	/* GSO will handle the following emulations directly. */
2018 	if (netif_needs_gso(dev, skb))
2019 		goto gso;
2020 
2021 	if (skb_has_frags(skb) &&
2022 	    !(dev->features & NETIF_F_FRAGLIST) &&
2023 	    __skb_linearize(skb))
2024 		goto out_kfree_skb;
2025 
2026 	/* Fragmented skb is linearized if device does not support SG,
2027 	 * or if at least one of fragments is in highmem and device
2028 	 * does not support DMA from it.
2029 	 */
2030 	if (skb_shinfo(skb)->nr_frags &&
2031 	    (!(dev->features & NETIF_F_SG) || illegal_highdma(dev, skb)) &&
2032 	    __skb_linearize(skb))
2033 		goto out_kfree_skb;
2034 
2035 	/* If packet is not checksummed and device does not support
2036 	 * checksumming for this protocol, complete checksumming here.
2037 	 */
2038 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
2039 		skb_set_transport_header(skb, skb->csum_start -
2040 					      skb_headroom(skb));
2041 		if (!dev_can_checksum(dev, skb) && skb_checksum_help(skb))
2042 			goto out_kfree_skb;
2043 	}
2044 
2045 gso:
2046 	/* Disable soft irqs for various locks below. Also
2047 	 * stops preemption for RCU.
2048 	 */
2049 	rcu_read_lock_bh();
2050 
2051 	txq = dev_pick_tx(dev, skb);
2052 	q = rcu_dereference(txq->qdisc);
2053 
2054 #ifdef CONFIG_NET_CLS_ACT
2055 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2056 #endif
2057 	if (q->enqueue) {
2058 		rc = __dev_xmit_skb(skb, q, dev, txq);
2059 		goto out;
2060 	}
2061 
2062 	/* The device has no queue. Common case for software devices:
2063 	   loopback, all the sorts of tunnels...
2064 
2065 	   Really, it is unlikely that netif_tx_lock protection is necessary
2066 	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
2067 	   counters.)
2068 	   However, it is possible, that they rely on protection
2069 	   made by us here.
2070 
2071 	   Check this and shot the lock. It is not prone from deadlocks.
2072 	   Either shot noqueue qdisc, it is even simpler 8)
2073 	 */
2074 	if (dev->flags & IFF_UP) {
2075 		int cpu = smp_processor_id(); /* ok because BHs are off */
2076 
2077 		if (txq->xmit_lock_owner != cpu) {
2078 
2079 			HARD_TX_LOCK(dev, txq, cpu);
2080 
2081 			if (!netif_tx_queue_stopped(txq)) {
2082 				rc = dev_hard_start_xmit(skb, dev, txq);
2083 				if (dev_xmit_complete(rc)) {
2084 					HARD_TX_UNLOCK(dev, txq);
2085 					goto out;
2086 				}
2087 			}
2088 			HARD_TX_UNLOCK(dev, txq);
2089 			if (net_ratelimit())
2090 				printk(KERN_CRIT "Virtual device %s asks to "
2091 				       "queue packet!\n", dev->name);
2092 		} else {
2093 			/* Recursion is detected! It is possible,
2094 			 * unfortunately */
2095 			if (net_ratelimit())
2096 				printk(KERN_CRIT "Dead loop on virtual device "
2097 				       "%s, fix it urgently!\n", dev->name);
2098 		}
2099 	}
2100 
2101 	rc = -ENETDOWN;
2102 	rcu_read_unlock_bh();
2103 
2104 out_kfree_skb:
2105 	kfree_skb(skb);
2106 	return rc;
2107 out:
2108 	rcu_read_unlock_bh();
2109 	return rc;
2110 }
2111 EXPORT_SYMBOL(dev_queue_xmit);
2112 
2113 
2114 /*=======================================================================
2115 			Receiver routines
2116   =======================================================================*/
2117 
2118 int netdev_max_backlog __read_mostly = 1000;
2119 int netdev_budget __read_mostly = 300;
2120 int weight_p __read_mostly = 64;            /* old backlog weight */
2121 
2122 DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
2123 
2124 
2125 /**
2126  *	netif_rx	-	post buffer to the network code
2127  *	@skb: buffer to post
2128  *
2129  *	This function receives a packet from a device driver and queues it for
2130  *	the upper (protocol) levels to process.  It always succeeds. The buffer
2131  *	may be dropped during processing for congestion control or by the
2132  *	protocol layers.
2133  *
2134  *	return values:
2135  *	NET_RX_SUCCESS	(no congestion)
2136  *	NET_RX_DROP     (packet was dropped)
2137  *
2138  */
2139 
2140 int netif_rx(struct sk_buff *skb)
2141 {
2142 	struct softnet_data *queue;
2143 	unsigned long flags;
2144 
2145 	/* if netpoll wants it, pretend we never saw it */
2146 	if (netpoll_rx(skb))
2147 		return NET_RX_DROP;
2148 
2149 	if (!skb->tstamp.tv64)
2150 		net_timestamp(skb);
2151 
2152 	/*
2153 	 * The code is rearranged so that the path is the most
2154 	 * short when CPU is congested, but is still operating.
2155 	 */
2156 	local_irq_save(flags);
2157 	queue = &__get_cpu_var(softnet_data);
2158 
2159 	__get_cpu_var(netdev_rx_stat).total++;
2160 	if (queue->input_pkt_queue.qlen <= netdev_max_backlog) {
2161 		if (queue->input_pkt_queue.qlen) {
2162 enqueue:
2163 			__skb_queue_tail(&queue->input_pkt_queue, skb);
2164 			local_irq_restore(flags);
2165 			return NET_RX_SUCCESS;
2166 		}
2167 
2168 		napi_schedule(&queue->backlog);
2169 		goto enqueue;
2170 	}
2171 
2172 	__get_cpu_var(netdev_rx_stat).dropped++;
2173 	local_irq_restore(flags);
2174 
2175 	kfree_skb(skb);
2176 	return NET_RX_DROP;
2177 }
2178 EXPORT_SYMBOL(netif_rx);
2179 
2180 int netif_rx_ni(struct sk_buff *skb)
2181 {
2182 	int err;
2183 
2184 	preempt_disable();
2185 	err = netif_rx(skb);
2186 	if (local_softirq_pending())
2187 		do_softirq();
2188 	preempt_enable();
2189 
2190 	return err;
2191 }
2192 EXPORT_SYMBOL(netif_rx_ni);
2193 
2194 static void net_tx_action(struct softirq_action *h)
2195 {
2196 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
2197 
2198 	if (sd->completion_queue) {
2199 		struct sk_buff *clist;
2200 
2201 		local_irq_disable();
2202 		clist = sd->completion_queue;
2203 		sd->completion_queue = NULL;
2204 		local_irq_enable();
2205 
2206 		while (clist) {
2207 			struct sk_buff *skb = clist;
2208 			clist = clist->next;
2209 
2210 			WARN_ON(atomic_read(&skb->users));
2211 			__kfree_skb(skb);
2212 		}
2213 	}
2214 
2215 	if (sd->output_queue) {
2216 		struct Qdisc *head;
2217 
2218 		local_irq_disable();
2219 		head = sd->output_queue;
2220 		sd->output_queue = NULL;
2221 		local_irq_enable();
2222 
2223 		while (head) {
2224 			struct Qdisc *q = head;
2225 			spinlock_t *root_lock;
2226 
2227 			head = head->next_sched;
2228 
2229 			root_lock = qdisc_lock(q);
2230 			if (spin_trylock(root_lock)) {
2231 				smp_mb__before_clear_bit();
2232 				clear_bit(__QDISC_STATE_SCHED,
2233 					  &q->state);
2234 				qdisc_run(q);
2235 				spin_unlock(root_lock);
2236 			} else {
2237 				if (!test_bit(__QDISC_STATE_DEACTIVATED,
2238 					      &q->state)) {
2239 					__netif_reschedule(q);
2240 				} else {
2241 					smp_mb__before_clear_bit();
2242 					clear_bit(__QDISC_STATE_SCHED,
2243 						  &q->state);
2244 				}
2245 			}
2246 		}
2247 	}
2248 }
2249 
2250 static inline int deliver_skb(struct sk_buff *skb,
2251 			      struct packet_type *pt_prev,
2252 			      struct net_device *orig_dev)
2253 {
2254 	atomic_inc(&skb->users);
2255 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2256 }
2257 
2258 #if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
2259 
2260 #if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
2261 /* This hook is defined here for ATM LANE */
2262 int (*br_fdb_test_addr_hook)(struct net_device *dev,
2263 			     unsigned char *addr) __read_mostly;
2264 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
2265 #endif
2266 
2267 /*
2268  * If bridge module is loaded call bridging hook.
2269  *  returns NULL if packet was consumed.
2270  */
2271 struct sk_buff *(*br_handle_frame_hook)(struct net_bridge_port *p,
2272 					struct sk_buff *skb) __read_mostly;
2273 EXPORT_SYMBOL_GPL(br_handle_frame_hook);
2274 
2275 static inline struct sk_buff *handle_bridge(struct sk_buff *skb,
2276 					    struct packet_type **pt_prev, int *ret,
2277 					    struct net_device *orig_dev)
2278 {
2279 	struct net_bridge_port *port;
2280 
2281 	if (skb->pkt_type == PACKET_LOOPBACK ||
2282 	    (port = rcu_dereference(skb->dev->br_port)) == NULL)
2283 		return skb;
2284 
2285 	if (*pt_prev) {
2286 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
2287 		*pt_prev = NULL;
2288 	}
2289 
2290 	return br_handle_frame_hook(port, skb);
2291 }
2292 #else
2293 #define handle_bridge(skb, pt_prev, ret, orig_dev)	(skb)
2294 #endif
2295 
2296 #if defined(CONFIG_MACVLAN) || defined(CONFIG_MACVLAN_MODULE)
2297 struct sk_buff *(*macvlan_handle_frame_hook)(struct sk_buff *skb) __read_mostly;
2298 EXPORT_SYMBOL_GPL(macvlan_handle_frame_hook);
2299 
2300 static inline struct sk_buff *handle_macvlan(struct sk_buff *skb,
2301 					     struct packet_type **pt_prev,
2302 					     int *ret,
2303 					     struct net_device *orig_dev)
2304 {
2305 	if (skb->dev->macvlan_port == NULL)
2306 		return skb;
2307 
2308 	if (*pt_prev) {
2309 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
2310 		*pt_prev = NULL;
2311 	}
2312 	return macvlan_handle_frame_hook(skb);
2313 }
2314 #else
2315 #define handle_macvlan(skb, pt_prev, ret, orig_dev)	(skb)
2316 #endif
2317 
2318 #ifdef CONFIG_NET_CLS_ACT
2319 /* TODO: Maybe we should just force sch_ingress to be compiled in
2320  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
2321  * a compare and 2 stores extra right now if we dont have it on
2322  * but have CONFIG_NET_CLS_ACT
2323  * NOTE: This doesnt stop any functionality; if you dont have
2324  * the ingress scheduler, you just cant add policies on ingress.
2325  *
2326  */
2327 static int ing_filter(struct sk_buff *skb)
2328 {
2329 	struct net_device *dev = skb->dev;
2330 	u32 ttl = G_TC_RTTL(skb->tc_verd);
2331 	struct netdev_queue *rxq;
2332 	int result = TC_ACT_OK;
2333 	struct Qdisc *q;
2334 
2335 	if (MAX_RED_LOOP < ttl++) {
2336 		printk(KERN_WARNING
2337 		       "Redir loop detected Dropping packet (%d->%d)\n",
2338 		       skb->skb_iif, dev->ifindex);
2339 		return TC_ACT_SHOT;
2340 	}
2341 
2342 	skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
2343 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
2344 
2345 	rxq = &dev->rx_queue;
2346 
2347 	q = rxq->qdisc;
2348 	if (q != &noop_qdisc) {
2349 		spin_lock(qdisc_lock(q));
2350 		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
2351 			result = qdisc_enqueue_root(skb, q);
2352 		spin_unlock(qdisc_lock(q));
2353 	}
2354 
2355 	return result;
2356 }
2357 
2358 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
2359 					 struct packet_type **pt_prev,
2360 					 int *ret, struct net_device *orig_dev)
2361 {
2362 	if (skb->dev->rx_queue.qdisc == &noop_qdisc)
2363 		goto out;
2364 
2365 	if (*pt_prev) {
2366 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
2367 		*pt_prev = NULL;
2368 	} else {
2369 		/* Huh? Why does turning on AF_PACKET affect this? */
2370 		skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
2371 	}
2372 
2373 	switch (ing_filter(skb)) {
2374 	case TC_ACT_SHOT:
2375 	case TC_ACT_STOLEN:
2376 		kfree_skb(skb);
2377 		return NULL;
2378 	}
2379 
2380 out:
2381 	skb->tc_verd = 0;
2382 	return skb;
2383 }
2384 #endif
2385 
2386 /*
2387  * 	netif_nit_deliver - deliver received packets to network taps
2388  * 	@skb: buffer
2389  *
2390  * 	This function is used to deliver incoming packets to network
2391  * 	taps. It should be used when the normal netif_receive_skb path
2392  * 	is bypassed, for example because of VLAN acceleration.
2393  */
2394 void netif_nit_deliver(struct sk_buff *skb)
2395 {
2396 	struct packet_type *ptype;
2397 
2398 	if (list_empty(&ptype_all))
2399 		return;
2400 
2401 	skb_reset_network_header(skb);
2402 	skb_reset_transport_header(skb);
2403 	skb->mac_len = skb->network_header - skb->mac_header;
2404 
2405 	rcu_read_lock();
2406 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
2407 		if (!ptype->dev || ptype->dev == skb->dev)
2408 			deliver_skb(skb, ptype, skb->dev);
2409 	}
2410 	rcu_read_unlock();
2411 }
2412 
2413 /**
2414  *	netif_receive_skb - process receive buffer from network
2415  *	@skb: buffer to process
2416  *
2417  *	netif_receive_skb() is the main receive data processing function.
2418  *	It always succeeds. The buffer may be dropped during processing
2419  *	for congestion control or by the protocol layers.
2420  *
2421  *	This function may only be called from softirq context and interrupts
2422  *	should be enabled.
2423  *
2424  *	Return values (usually ignored):
2425  *	NET_RX_SUCCESS: no congestion
2426  *	NET_RX_DROP: packet was dropped
2427  */
2428 int netif_receive_skb(struct sk_buff *skb)
2429 {
2430 	struct packet_type *ptype, *pt_prev;
2431 	struct net_device *orig_dev;
2432 	struct net_device *null_or_orig;
2433 	struct net_device *null_or_bond;
2434 	int ret = NET_RX_DROP;
2435 	__be16 type;
2436 
2437 	if (!skb->tstamp.tv64)
2438 		net_timestamp(skb);
2439 
2440 	if (vlan_tx_tag_present(skb) && vlan_hwaccel_do_receive(skb))
2441 		return NET_RX_SUCCESS;
2442 
2443 	/* if we've gotten here through NAPI, check netpoll */
2444 	if (netpoll_receive_skb(skb))
2445 		return NET_RX_DROP;
2446 
2447 	if (!skb->skb_iif)
2448 		skb->skb_iif = skb->dev->ifindex;
2449 
2450 	null_or_orig = NULL;
2451 	orig_dev = skb->dev;
2452 	if (orig_dev->master) {
2453 		if (skb_bond_should_drop(skb))
2454 			null_or_orig = orig_dev; /* deliver only exact match */
2455 		else
2456 			skb->dev = orig_dev->master;
2457 	}
2458 
2459 	__get_cpu_var(netdev_rx_stat).total++;
2460 
2461 	skb_reset_network_header(skb);
2462 	skb_reset_transport_header(skb);
2463 	skb->mac_len = skb->network_header - skb->mac_header;
2464 
2465 	pt_prev = NULL;
2466 
2467 	rcu_read_lock();
2468 
2469 #ifdef CONFIG_NET_CLS_ACT
2470 	if (skb->tc_verd & TC_NCLS) {
2471 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
2472 		goto ncls;
2473 	}
2474 #endif
2475 
2476 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
2477 		if (ptype->dev == null_or_orig || ptype->dev == skb->dev ||
2478 		    ptype->dev == orig_dev) {
2479 			if (pt_prev)
2480 				ret = deliver_skb(skb, pt_prev, orig_dev);
2481 			pt_prev = ptype;
2482 		}
2483 	}
2484 
2485 #ifdef CONFIG_NET_CLS_ACT
2486 	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
2487 	if (!skb)
2488 		goto out;
2489 ncls:
2490 #endif
2491 
2492 	skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
2493 	if (!skb)
2494 		goto out;
2495 	skb = handle_macvlan(skb, &pt_prev, &ret, orig_dev);
2496 	if (!skb)
2497 		goto out;
2498 
2499 	/*
2500 	 * Make sure frames received on VLAN interfaces stacked on
2501 	 * bonding interfaces still make their way to any base bonding
2502 	 * device that may have registered for a specific ptype.  The
2503 	 * handler may have to adjust skb->dev and orig_dev.
2504 	 */
2505 	null_or_bond = NULL;
2506 	if ((skb->dev->priv_flags & IFF_802_1Q_VLAN) &&
2507 	    (vlan_dev_real_dev(skb->dev)->priv_flags & IFF_BONDING)) {
2508 		null_or_bond = vlan_dev_real_dev(skb->dev);
2509 	}
2510 
2511 	type = skb->protocol;
2512 	list_for_each_entry_rcu(ptype,
2513 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
2514 		if (ptype->type == type && (ptype->dev == null_or_orig ||
2515 		     ptype->dev == skb->dev || ptype->dev == orig_dev ||
2516 		     ptype->dev == null_or_bond)) {
2517 			if (pt_prev)
2518 				ret = deliver_skb(skb, pt_prev, orig_dev);
2519 			pt_prev = ptype;
2520 		}
2521 	}
2522 
2523 	if (pt_prev) {
2524 		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2525 	} else {
2526 		kfree_skb(skb);
2527 		/* Jamal, now you will not able to escape explaining
2528 		 * me how you were going to use this. :-)
2529 		 */
2530 		ret = NET_RX_DROP;
2531 	}
2532 
2533 out:
2534 	rcu_read_unlock();
2535 	return ret;
2536 }
2537 EXPORT_SYMBOL(netif_receive_skb);
2538 
2539 /* Network device is going away, flush any packets still pending  */
2540 static void flush_backlog(void *arg)
2541 {
2542 	struct net_device *dev = arg;
2543 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
2544 	struct sk_buff *skb, *tmp;
2545 
2546 	skb_queue_walk_safe(&queue->input_pkt_queue, skb, tmp)
2547 		if (skb->dev == dev) {
2548 			__skb_unlink(skb, &queue->input_pkt_queue);
2549 			kfree_skb(skb);
2550 		}
2551 }
2552 
2553 static int napi_gro_complete(struct sk_buff *skb)
2554 {
2555 	struct packet_type *ptype;
2556 	__be16 type = skb->protocol;
2557 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
2558 	int err = -ENOENT;
2559 
2560 	if (NAPI_GRO_CB(skb)->count == 1) {
2561 		skb_shinfo(skb)->gso_size = 0;
2562 		goto out;
2563 	}
2564 
2565 	rcu_read_lock();
2566 	list_for_each_entry_rcu(ptype, head, list) {
2567 		if (ptype->type != type || ptype->dev || !ptype->gro_complete)
2568 			continue;
2569 
2570 		err = ptype->gro_complete(skb);
2571 		break;
2572 	}
2573 	rcu_read_unlock();
2574 
2575 	if (err) {
2576 		WARN_ON(&ptype->list == head);
2577 		kfree_skb(skb);
2578 		return NET_RX_SUCCESS;
2579 	}
2580 
2581 out:
2582 	return netif_receive_skb(skb);
2583 }
2584 
2585 void napi_gro_flush(struct napi_struct *napi)
2586 {
2587 	struct sk_buff *skb, *next;
2588 
2589 	for (skb = napi->gro_list; skb; skb = next) {
2590 		next = skb->next;
2591 		skb->next = NULL;
2592 		napi_gro_complete(skb);
2593 	}
2594 
2595 	napi->gro_count = 0;
2596 	napi->gro_list = NULL;
2597 }
2598 EXPORT_SYMBOL(napi_gro_flush);
2599 
2600 enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
2601 {
2602 	struct sk_buff **pp = NULL;
2603 	struct packet_type *ptype;
2604 	__be16 type = skb->protocol;
2605 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
2606 	int same_flow;
2607 	int mac_len;
2608 	enum gro_result ret;
2609 
2610 	if (!(skb->dev->features & NETIF_F_GRO))
2611 		goto normal;
2612 
2613 	if (skb_is_gso(skb) || skb_has_frags(skb))
2614 		goto normal;
2615 
2616 	rcu_read_lock();
2617 	list_for_each_entry_rcu(ptype, head, list) {
2618 		if (ptype->type != type || ptype->dev || !ptype->gro_receive)
2619 			continue;
2620 
2621 		skb_set_network_header(skb, skb_gro_offset(skb));
2622 		mac_len = skb->network_header - skb->mac_header;
2623 		skb->mac_len = mac_len;
2624 		NAPI_GRO_CB(skb)->same_flow = 0;
2625 		NAPI_GRO_CB(skb)->flush = 0;
2626 		NAPI_GRO_CB(skb)->free = 0;
2627 
2628 		pp = ptype->gro_receive(&napi->gro_list, skb);
2629 		break;
2630 	}
2631 	rcu_read_unlock();
2632 
2633 	if (&ptype->list == head)
2634 		goto normal;
2635 
2636 	same_flow = NAPI_GRO_CB(skb)->same_flow;
2637 	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
2638 
2639 	if (pp) {
2640 		struct sk_buff *nskb = *pp;
2641 
2642 		*pp = nskb->next;
2643 		nskb->next = NULL;
2644 		napi_gro_complete(nskb);
2645 		napi->gro_count--;
2646 	}
2647 
2648 	if (same_flow)
2649 		goto ok;
2650 
2651 	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
2652 		goto normal;
2653 
2654 	napi->gro_count++;
2655 	NAPI_GRO_CB(skb)->count = 1;
2656 	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
2657 	skb->next = napi->gro_list;
2658 	napi->gro_list = skb;
2659 	ret = GRO_HELD;
2660 
2661 pull:
2662 	if (skb_headlen(skb) < skb_gro_offset(skb)) {
2663 		int grow = skb_gro_offset(skb) - skb_headlen(skb);
2664 
2665 		BUG_ON(skb->end - skb->tail < grow);
2666 
2667 		memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
2668 
2669 		skb->tail += grow;
2670 		skb->data_len -= grow;
2671 
2672 		skb_shinfo(skb)->frags[0].page_offset += grow;
2673 		skb_shinfo(skb)->frags[0].size -= grow;
2674 
2675 		if (unlikely(!skb_shinfo(skb)->frags[0].size)) {
2676 			put_page(skb_shinfo(skb)->frags[0].page);
2677 			memmove(skb_shinfo(skb)->frags,
2678 				skb_shinfo(skb)->frags + 1,
2679 				--skb_shinfo(skb)->nr_frags);
2680 		}
2681 	}
2682 
2683 ok:
2684 	return ret;
2685 
2686 normal:
2687 	ret = GRO_NORMAL;
2688 	goto pull;
2689 }
2690 EXPORT_SYMBOL(dev_gro_receive);
2691 
2692 static gro_result_t
2693 __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
2694 {
2695 	struct sk_buff *p;
2696 
2697 	if (netpoll_rx_on(skb))
2698 		return GRO_NORMAL;
2699 
2700 	for (p = napi->gro_list; p; p = p->next) {
2701 		NAPI_GRO_CB(p)->same_flow =
2702 			(p->dev == skb->dev) &&
2703 			!compare_ether_header(skb_mac_header(p),
2704 					      skb_gro_mac_header(skb));
2705 		NAPI_GRO_CB(p)->flush = 0;
2706 	}
2707 
2708 	return dev_gro_receive(napi, skb);
2709 }
2710 
2711 gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
2712 {
2713 	switch (ret) {
2714 	case GRO_NORMAL:
2715 		if (netif_receive_skb(skb))
2716 			ret = GRO_DROP;
2717 		break;
2718 
2719 	case GRO_DROP:
2720 	case GRO_MERGED_FREE:
2721 		kfree_skb(skb);
2722 		break;
2723 
2724 	case GRO_HELD:
2725 	case GRO_MERGED:
2726 		break;
2727 	}
2728 
2729 	return ret;
2730 }
2731 EXPORT_SYMBOL(napi_skb_finish);
2732 
2733 void skb_gro_reset_offset(struct sk_buff *skb)
2734 {
2735 	NAPI_GRO_CB(skb)->data_offset = 0;
2736 	NAPI_GRO_CB(skb)->frag0 = NULL;
2737 	NAPI_GRO_CB(skb)->frag0_len = 0;
2738 
2739 	if (skb->mac_header == skb->tail &&
2740 	    !PageHighMem(skb_shinfo(skb)->frags[0].page)) {
2741 		NAPI_GRO_CB(skb)->frag0 =
2742 			page_address(skb_shinfo(skb)->frags[0].page) +
2743 			skb_shinfo(skb)->frags[0].page_offset;
2744 		NAPI_GRO_CB(skb)->frag0_len = skb_shinfo(skb)->frags[0].size;
2745 	}
2746 }
2747 EXPORT_SYMBOL(skb_gro_reset_offset);
2748 
2749 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
2750 {
2751 	skb_gro_reset_offset(skb);
2752 
2753 	return napi_skb_finish(__napi_gro_receive(napi, skb), skb);
2754 }
2755 EXPORT_SYMBOL(napi_gro_receive);
2756 
2757 void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
2758 {
2759 	__skb_pull(skb, skb_headlen(skb));
2760 	skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb));
2761 
2762 	napi->skb = skb;
2763 }
2764 EXPORT_SYMBOL(napi_reuse_skb);
2765 
2766 struct sk_buff *napi_get_frags(struct napi_struct *napi)
2767 {
2768 	struct sk_buff *skb = napi->skb;
2769 
2770 	if (!skb) {
2771 		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
2772 		if (skb)
2773 			napi->skb = skb;
2774 	}
2775 	return skb;
2776 }
2777 EXPORT_SYMBOL(napi_get_frags);
2778 
2779 gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
2780 			       gro_result_t ret)
2781 {
2782 	switch (ret) {
2783 	case GRO_NORMAL:
2784 	case GRO_HELD:
2785 		skb->protocol = eth_type_trans(skb, napi->dev);
2786 
2787 		if (ret == GRO_HELD)
2788 			skb_gro_pull(skb, -ETH_HLEN);
2789 		else if (netif_receive_skb(skb))
2790 			ret = GRO_DROP;
2791 		break;
2792 
2793 	case GRO_DROP:
2794 	case GRO_MERGED_FREE:
2795 		napi_reuse_skb(napi, skb);
2796 		break;
2797 
2798 	case GRO_MERGED:
2799 		break;
2800 	}
2801 
2802 	return ret;
2803 }
2804 EXPORT_SYMBOL(napi_frags_finish);
2805 
2806 struct sk_buff *napi_frags_skb(struct napi_struct *napi)
2807 {
2808 	struct sk_buff *skb = napi->skb;
2809 	struct ethhdr *eth;
2810 	unsigned int hlen;
2811 	unsigned int off;
2812 
2813 	napi->skb = NULL;
2814 
2815 	skb_reset_mac_header(skb);
2816 	skb_gro_reset_offset(skb);
2817 
2818 	off = skb_gro_offset(skb);
2819 	hlen = off + sizeof(*eth);
2820 	eth = skb_gro_header_fast(skb, off);
2821 	if (skb_gro_header_hard(skb, hlen)) {
2822 		eth = skb_gro_header_slow(skb, hlen, off);
2823 		if (unlikely(!eth)) {
2824 			napi_reuse_skb(napi, skb);
2825 			skb = NULL;
2826 			goto out;
2827 		}
2828 	}
2829 
2830 	skb_gro_pull(skb, sizeof(*eth));
2831 
2832 	/*
2833 	 * This works because the only protocols we care about don't require
2834 	 * special handling.  We'll fix it up properly at the end.
2835 	 */
2836 	skb->protocol = eth->h_proto;
2837 
2838 out:
2839 	return skb;
2840 }
2841 EXPORT_SYMBOL(napi_frags_skb);
2842 
2843 gro_result_t napi_gro_frags(struct napi_struct *napi)
2844 {
2845 	struct sk_buff *skb = napi_frags_skb(napi);
2846 
2847 	if (!skb)
2848 		return GRO_DROP;
2849 
2850 	return napi_frags_finish(napi, skb, __napi_gro_receive(napi, skb));
2851 }
2852 EXPORT_SYMBOL(napi_gro_frags);
2853 
2854 static int process_backlog(struct napi_struct *napi, int quota)
2855 {
2856 	int work = 0;
2857 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
2858 	unsigned long start_time = jiffies;
2859 
2860 	napi->weight = weight_p;
2861 	do {
2862 		struct sk_buff *skb;
2863 
2864 		local_irq_disable();
2865 		skb = __skb_dequeue(&queue->input_pkt_queue);
2866 		if (!skb) {
2867 			__napi_complete(napi);
2868 			local_irq_enable();
2869 			break;
2870 		}
2871 		local_irq_enable();
2872 
2873 		netif_receive_skb(skb);
2874 	} while (++work < quota && jiffies == start_time);
2875 
2876 	return work;
2877 }
2878 
2879 /**
2880  * __napi_schedule - schedule for receive
2881  * @n: entry to schedule
2882  *
2883  * The entry's receive function will be scheduled to run
2884  */
2885 void __napi_schedule(struct napi_struct *n)
2886 {
2887 	unsigned long flags;
2888 
2889 	local_irq_save(flags);
2890 	list_add_tail(&n->poll_list, &__get_cpu_var(softnet_data).poll_list);
2891 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2892 	local_irq_restore(flags);
2893 }
2894 EXPORT_SYMBOL(__napi_schedule);
2895 
2896 void __napi_complete(struct napi_struct *n)
2897 {
2898 	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
2899 	BUG_ON(n->gro_list);
2900 
2901 	list_del(&n->poll_list);
2902 	smp_mb__before_clear_bit();
2903 	clear_bit(NAPI_STATE_SCHED, &n->state);
2904 }
2905 EXPORT_SYMBOL(__napi_complete);
2906 
2907 void napi_complete(struct napi_struct *n)
2908 {
2909 	unsigned long flags;
2910 
2911 	/*
2912 	 * don't let napi dequeue from the cpu poll list
2913 	 * just in case its running on a different cpu
2914 	 */
2915 	if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
2916 		return;
2917 
2918 	napi_gro_flush(n);
2919 	local_irq_save(flags);
2920 	__napi_complete(n);
2921 	local_irq_restore(flags);
2922 }
2923 EXPORT_SYMBOL(napi_complete);
2924 
2925 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
2926 		    int (*poll)(struct napi_struct *, int), int weight)
2927 {
2928 	INIT_LIST_HEAD(&napi->poll_list);
2929 	napi->gro_count = 0;
2930 	napi->gro_list = NULL;
2931 	napi->skb = NULL;
2932 	napi->poll = poll;
2933 	napi->weight = weight;
2934 	list_add(&napi->dev_list, &dev->napi_list);
2935 	napi->dev = dev;
2936 #ifdef CONFIG_NETPOLL
2937 	spin_lock_init(&napi->poll_lock);
2938 	napi->poll_owner = -1;
2939 #endif
2940 	set_bit(NAPI_STATE_SCHED, &napi->state);
2941 }
2942 EXPORT_SYMBOL(netif_napi_add);
2943 
2944 void netif_napi_del(struct napi_struct *napi)
2945 {
2946 	struct sk_buff *skb, *next;
2947 
2948 	list_del_init(&napi->dev_list);
2949 	napi_free_frags(napi);
2950 
2951 	for (skb = napi->gro_list; skb; skb = next) {
2952 		next = skb->next;
2953 		skb->next = NULL;
2954 		kfree_skb(skb);
2955 	}
2956 
2957 	napi->gro_list = NULL;
2958 	napi->gro_count = 0;
2959 }
2960 EXPORT_SYMBOL(netif_napi_del);
2961 
2962 
2963 static void net_rx_action(struct softirq_action *h)
2964 {
2965 	struct list_head *list = &__get_cpu_var(softnet_data).poll_list;
2966 	unsigned long time_limit = jiffies + 2;
2967 	int budget = netdev_budget;
2968 	void *have;
2969 
2970 	local_irq_disable();
2971 
2972 	while (!list_empty(list)) {
2973 		struct napi_struct *n;
2974 		int work, weight;
2975 
2976 		/* If softirq window is exhuasted then punt.
2977 		 * Allow this to run for 2 jiffies since which will allow
2978 		 * an average latency of 1.5/HZ.
2979 		 */
2980 		if (unlikely(budget <= 0 || time_after(jiffies, time_limit)))
2981 			goto softnet_break;
2982 
2983 		local_irq_enable();
2984 
2985 		/* Even though interrupts have been re-enabled, this
2986 		 * access is safe because interrupts can only add new
2987 		 * entries to the tail of this list, and only ->poll()
2988 		 * calls can remove this head entry from the list.
2989 		 */
2990 		n = list_entry(list->next, struct napi_struct, poll_list);
2991 
2992 		have = netpoll_poll_lock(n);
2993 
2994 		weight = n->weight;
2995 
2996 		/* This NAPI_STATE_SCHED test is for avoiding a race
2997 		 * with netpoll's poll_napi().  Only the entity which
2998 		 * obtains the lock and sees NAPI_STATE_SCHED set will
2999 		 * actually make the ->poll() call.  Therefore we avoid
3000 		 * accidently calling ->poll() when NAPI is not scheduled.
3001 		 */
3002 		work = 0;
3003 		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
3004 			work = n->poll(n, weight);
3005 			trace_napi_poll(n);
3006 		}
3007 
3008 		WARN_ON_ONCE(work > weight);
3009 
3010 		budget -= work;
3011 
3012 		local_irq_disable();
3013 
3014 		/* Drivers must not modify the NAPI state if they
3015 		 * consume the entire weight.  In such cases this code
3016 		 * still "owns" the NAPI instance and therefore can
3017 		 * move the instance around on the list at-will.
3018 		 */
3019 		if (unlikely(work == weight)) {
3020 			if (unlikely(napi_disable_pending(n))) {
3021 				local_irq_enable();
3022 				napi_complete(n);
3023 				local_irq_disable();
3024 			} else
3025 				list_move_tail(&n->poll_list, list);
3026 		}
3027 
3028 		netpoll_poll_unlock(have);
3029 	}
3030 out:
3031 	local_irq_enable();
3032 
3033 #ifdef CONFIG_NET_DMA
3034 	/*
3035 	 * There may not be any more sk_buffs coming right now, so push
3036 	 * any pending DMA copies to hardware
3037 	 */
3038 	dma_issue_pending_all();
3039 #endif
3040 
3041 	return;
3042 
3043 softnet_break:
3044 	__get_cpu_var(netdev_rx_stat).time_squeeze++;
3045 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
3046 	goto out;
3047 }
3048 
3049 static gifconf_func_t *gifconf_list[NPROTO];
3050 
3051 /**
3052  *	register_gifconf	-	register a SIOCGIF handler
3053  *	@family: Address family
3054  *	@gifconf: Function handler
3055  *
3056  *	Register protocol dependent address dumping routines. The handler
3057  *	that is passed must not be freed or reused until it has been replaced
3058  *	by another handler.
3059  */
3060 int register_gifconf(unsigned int family, gifconf_func_t *gifconf)
3061 {
3062 	if (family >= NPROTO)
3063 		return -EINVAL;
3064 	gifconf_list[family] = gifconf;
3065 	return 0;
3066 }
3067 EXPORT_SYMBOL(register_gifconf);
3068 
3069 
3070 /*
3071  *	Map an interface index to its name (SIOCGIFNAME)
3072  */
3073 
3074 /*
3075  *	We need this ioctl for efficient implementation of the
3076  *	if_indextoname() function required by the IPv6 API.  Without
3077  *	it, we would have to search all the interfaces to find a
3078  *	match.  --pb
3079  */
3080 
3081 static int dev_ifname(struct net *net, struct ifreq __user *arg)
3082 {
3083 	struct net_device *dev;
3084 	struct ifreq ifr;
3085 
3086 	/*
3087 	 *	Fetch the caller's info block.
3088 	 */
3089 
3090 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
3091 		return -EFAULT;
3092 
3093 	rcu_read_lock();
3094 	dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex);
3095 	if (!dev) {
3096 		rcu_read_unlock();
3097 		return -ENODEV;
3098 	}
3099 
3100 	strcpy(ifr.ifr_name, dev->name);
3101 	rcu_read_unlock();
3102 
3103 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
3104 		return -EFAULT;
3105 	return 0;
3106 }
3107 
3108 /*
3109  *	Perform a SIOCGIFCONF call. This structure will change
3110  *	size eventually, and there is nothing I can do about it.
3111  *	Thus we will need a 'compatibility mode'.
3112  */
3113 
3114 static int dev_ifconf(struct net *net, char __user *arg)
3115 {
3116 	struct ifconf ifc;
3117 	struct net_device *dev;
3118 	char __user *pos;
3119 	int len;
3120 	int total;
3121 	int i;
3122 
3123 	/*
3124 	 *	Fetch the caller's info block.
3125 	 */
3126 
3127 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
3128 		return -EFAULT;
3129 
3130 	pos = ifc.ifc_buf;
3131 	len = ifc.ifc_len;
3132 
3133 	/*
3134 	 *	Loop over the interfaces, and write an info block for each.
3135 	 */
3136 
3137 	total = 0;
3138 	for_each_netdev(net, dev) {
3139 		for (i = 0; i < NPROTO; i++) {
3140 			if (gifconf_list[i]) {
3141 				int done;
3142 				if (!pos)
3143 					done = gifconf_list[i](dev, NULL, 0);
3144 				else
3145 					done = gifconf_list[i](dev, pos + total,
3146 							       len - total);
3147 				if (done < 0)
3148 					return -EFAULT;
3149 				total += done;
3150 			}
3151 		}
3152 	}
3153 
3154 	/*
3155 	 *	All done.  Write the updated control block back to the caller.
3156 	 */
3157 	ifc.ifc_len = total;
3158 
3159 	/*
3160 	 * 	Both BSD and Solaris return 0 here, so we do too.
3161 	 */
3162 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
3163 }
3164 
3165 #ifdef CONFIG_PROC_FS
3166 /*
3167  *	This is invoked by the /proc filesystem handler to display a device
3168  *	in detail.
3169  */
3170 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
3171 	__acquires(RCU)
3172 {
3173 	struct net *net = seq_file_net(seq);
3174 	loff_t off;
3175 	struct net_device *dev;
3176 
3177 	rcu_read_lock();
3178 	if (!*pos)
3179 		return SEQ_START_TOKEN;
3180 
3181 	off = 1;
3182 	for_each_netdev_rcu(net, dev)
3183 		if (off++ == *pos)
3184 			return dev;
3185 
3186 	return NULL;
3187 }
3188 
3189 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3190 {
3191 	struct net_device *dev = (v == SEQ_START_TOKEN) ?
3192 				  first_net_device(seq_file_net(seq)) :
3193 				  next_net_device((struct net_device *)v);
3194 
3195 	++*pos;
3196 	return rcu_dereference(dev);
3197 }
3198 
3199 void dev_seq_stop(struct seq_file *seq, void *v)
3200 	__releases(RCU)
3201 {
3202 	rcu_read_unlock();
3203 }
3204 
3205 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
3206 {
3207 	const struct net_device_stats *stats = dev_get_stats(dev);
3208 
3209 	seq_printf(seq, "%6s: %7lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu "
3210 		   "%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
3211 		   dev->name, stats->rx_bytes, stats->rx_packets,
3212 		   stats->rx_errors,
3213 		   stats->rx_dropped + stats->rx_missed_errors,
3214 		   stats->rx_fifo_errors,
3215 		   stats->rx_length_errors + stats->rx_over_errors +
3216 		    stats->rx_crc_errors + stats->rx_frame_errors,
3217 		   stats->rx_compressed, stats->multicast,
3218 		   stats->tx_bytes, stats->tx_packets,
3219 		   stats->tx_errors, stats->tx_dropped,
3220 		   stats->tx_fifo_errors, stats->collisions,
3221 		   stats->tx_carrier_errors +
3222 		    stats->tx_aborted_errors +
3223 		    stats->tx_window_errors +
3224 		    stats->tx_heartbeat_errors,
3225 		   stats->tx_compressed);
3226 }
3227 
3228 /*
3229  *	Called from the PROCfs module. This now uses the new arbitrary sized
3230  *	/proc/net interface to create /proc/net/dev
3231  */
3232 static int dev_seq_show(struct seq_file *seq, void *v)
3233 {
3234 	if (v == SEQ_START_TOKEN)
3235 		seq_puts(seq, "Inter-|   Receive                            "
3236 			      "                    |  Transmit\n"
3237 			      " face |bytes    packets errs drop fifo frame "
3238 			      "compressed multicast|bytes    packets errs "
3239 			      "drop fifo colls carrier compressed\n");
3240 	else
3241 		dev_seq_printf_stats(seq, v);
3242 	return 0;
3243 }
3244 
3245 static struct netif_rx_stats *softnet_get_online(loff_t *pos)
3246 {
3247 	struct netif_rx_stats *rc = NULL;
3248 
3249 	while (*pos < nr_cpu_ids)
3250 		if (cpu_online(*pos)) {
3251 			rc = &per_cpu(netdev_rx_stat, *pos);
3252 			break;
3253 		} else
3254 			++*pos;
3255 	return rc;
3256 }
3257 
3258 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
3259 {
3260 	return softnet_get_online(pos);
3261 }
3262 
3263 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3264 {
3265 	++*pos;
3266 	return softnet_get_online(pos);
3267 }
3268 
3269 static void softnet_seq_stop(struct seq_file *seq, void *v)
3270 {
3271 }
3272 
3273 static int softnet_seq_show(struct seq_file *seq, void *v)
3274 {
3275 	struct netif_rx_stats *s = v;
3276 
3277 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
3278 		   s->total, s->dropped, s->time_squeeze, 0,
3279 		   0, 0, 0, 0, /* was fastroute */
3280 		   s->cpu_collision);
3281 	return 0;
3282 }
3283 
3284 static const struct seq_operations dev_seq_ops = {
3285 	.start = dev_seq_start,
3286 	.next  = dev_seq_next,
3287 	.stop  = dev_seq_stop,
3288 	.show  = dev_seq_show,
3289 };
3290 
3291 static int dev_seq_open(struct inode *inode, struct file *file)
3292 {
3293 	return seq_open_net(inode, file, &dev_seq_ops,
3294 			    sizeof(struct seq_net_private));
3295 }
3296 
3297 static const struct file_operations dev_seq_fops = {
3298 	.owner	 = THIS_MODULE,
3299 	.open    = dev_seq_open,
3300 	.read    = seq_read,
3301 	.llseek  = seq_lseek,
3302 	.release = seq_release_net,
3303 };
3304 
3305 static const struct seq_operations softnet_seq_ops = {
3306 	.start = softnet_seq_start,
3307 	.next  = softnet_seq_next,
3308 	.stop  = softnet_seq_stop,
3309 	.show  = softnet_seq_show,
3310 };
3311 
3312 static int softnet_seq_open(struct inode *inode, struct file *file)
3313 {
3314 	return seq_open(file, &softnet_seq_ops);
3315 }
3316 
3317 static const struct file_operations softnet_seq_fops = {
3318 	.owner	 = THIS_MODULE,
3319 	.open    = softnet_seq_open,
3320 	.read    = seq_read,
3321 	.llseek  = seq_lseek,
3322 	.release = seq_release,
3323 };
3324 
3325 static void *ptype_get_idx(loff_t pos)
3326 {
3327 	struct packet_type *pt = NULL;
3328 	loff_t i = 0;
3329 	int t;
3330 
3331 	list_for_each_entry_rcu(pt, &ptype_all, list) {
3332 		if (i == pos)
3333 			return pt;
3334 		++i;
3335 	}
3336 
3337 	for (t = 0; t < PTYPE_HASH_SIZE; t++) {
3338 		list_for_each_entry_rcu(pt, &ptype_base[t], list) {
3339 			if (i == pos)
3340 				return pt;
3341 			++i;
3342 		}
3343 	}
3344 	return NULL;
3345 }
3346 
3347 static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
3348 	__acquires(RCU)
3349 {
3350 	rcu_read_lock();
3351 	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
3352 }
3353 
3354 static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3355 {
3356 	struct packet_type *pt;
3357 	struct list_head *nxt;
3358 	int hash;
3359 
3360 	++*pos;
3361 	if (v == SEQ_START_TOKEN)
3362 		return ptype_get_idx(0);
3363 
3364 	pt = v;
3365 	nxt = pt->list.next;
3366 	if (pt->type == htons(ETH_P_ALL)) {
3367 		if (nxt != &ptype_all)
3368 			goto found;
3369 		hash = 0;
3370 		nxt = ptype_base[0].next;
3371 	} else
3372 		hash = ntohs(pt->type) & PTYPE_HASH_MASK;
3373 
3374 	while (nxt == &ptype_base[hash]) {
3375 		if (++hash >= PTYPE_HASH_SIZE)
3376 			return NULL;
3377 		nxt = ptype_base[hash].next;
3378 	}
3379 found:
3380 	return list_entry(nxt, struct packet_type, list);
3381 }
3382 
3383 static void ptype_seq_stop(struct seq_file *seq, void *v)
3384 	__releases(RCU)
3385 {
3386 	rcu_read_unlock();
3387 }
3388 
3389 static int ptype_seq_show(struct seq_file *seq, void *v)
3390 {
3391 	struct packet_type *pt = v;
3392 
3393 	if (v == SEQ_START_TOKEN)
3394 		seq_puts(seq, "Type Device      Function\n");
3395 	else if (pt->dev == NULL || dev_net(pt->dev) == seq_file_net(seq)) {
3396 		if (pt->type == htons(ETH_P_ALL))
3397 			seq_puts(seq, "ALL ");
3398 		else
3399 			seq_printf(seq, "%04x", ntohs(pt->type));
3400 
3401 		seq_printf(seq, " %-8s %pF\n",
3402 			   pt->dev ? pt->dev->name : "", pt->func);
3403 	}
3404 
3405 	return 0;
3406 }
3407 
3408 static const struct seq_operations ptype_seq_ops = {
3409 	.start = ptype_seq_start,
3410 	.next  = ptype_seq_next,
3411 	.stop  = ptype_seq_stop,
3412 	.show  = ptype_seq_show,
3413 };
3414 
3415 static int ptype_seq_open(struct inode *inode, struct file *file)
3416 {
3417 	return seq_open_net(inode, file, &ptype_seq_ops,
3418 			sizeof(struct seq_net_private));
3419 }
3420 
3421 static const struct file_operations ptype_seq_fops = {
3422 	.owner	 = THIS_MODULE,
3423 	.open    = ptype_seq_open,
3424 	.read    = seq_read,
3425 	.llseek  = seq_lseek,
3426 	.release = seq_release_net,
3427 };
3428 
3429 
3430 static int __net_init dev_proc_net_init(struct net *net)
3431 {
3432 	int rc = -ENOMEM;
3433 
3434 	if (!proc_net_fops_create(net, "dev", S_IRUGO, &dev_seq_fops))
3435 		goto out;
3436 	if (!proc_net_fops_create(net, "softnet_stat", S_IRUGO, &softnet_seq_fops))
3437 		goto out_dev;
3438 	if (!proc_net_fops_create(net, "ptype", S_IRUGO, &ptype_seq_fops))
3439 		goto out_softnet;
3440 
3441 	if (wext_proc_init(net))
3442 		goto out_ptype;
3443 	rc = 0;
3444 out:
3445 	return rc;
3446 out_ptype:
3447 	proc_net_remove(net, "ptype");
3448 out_softnet:
3449 	proc_net_remove(net, "softnet_stat");
3450 out_dev:
3451 	proc_net_remove(net, "dev");
3452 	goto out;
3453 }
3454 
3455 static void __net_exit dev_proc_net_exit(struct net *net)
3456 {
3457 	wext_proc_exit(net);
3458 
3459 	proc_net_remove(net, "ptype");
3460 	proc_net_remove(net, "softnet_stat");
3461 	proc_net_remove(net, "dev");
3462 }
3463 
3464 static struct pernet_operations __net_initdata dev_proc_ops = {
3465 	.init = dev_proc_net_init,
3466 	.exit = dev_proc_net_exit,
3467 };
3468 
3469 static int __init dev_proc_init(void)
3470 {
3471 	return register_pernet_subsys(&dev_proc_ops);
3472 }
3473 #else
3474 #define dev_proc_init() 0
3475 #endif	/* CONFIG_PROC_FS */
3476 
3477 
3478 /**
3479  *	netdev_set_master	-	set up master/slave pair
3480  *	@slave: slave device
3481  *	@master: new master device
3482  *
3483  *	Changes the master device of the slave. Pass %NULL to break the
3484  *	bonding. The caller must hold the RTNL semaphore. On a failure
3485  *	a negative errno code is returned. On success the reference counts
3486  *	are adjusted, %RTM_NEWLINK is sent to the routing socket and the
3487  *	function returns zero.
3488  */
3489 int netdev_set_master(struct net_device *slave, struct net_device *master)
3490 {
3491 	struct net_device *old = slave->master;
3492 
3493 	ASSERT_RTNL();
3494 
3495 	if (master) {
3496 		if (old)
3497 			return -EBUSY;
3498 		dev_hold(master);
3499 	}
3500 
3501 	slave->master = master;
3502 
3503 	synchronize_net();
3504 
3505 	if (old)
3506 		dev_put(old);
3507 
3508 	if (master)
3509 		slave->flags |= IFF_SLAVE;
3510 	else
3511 		slave->flags &= ~IFF_SLAVE;
3512 
3513 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
3514 	return 0;
3515 }
3516 EXPORT_SYMBOL(netdev_set_master);
3517 
3518 static void dev_change_rx_flags(struct net_device *dev, int flags)
3519 {
3520 	const struct net_device_ops *ops = dev->netdev_ops;
3521 
3522 	if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
3523 		ops->ndo_change_rx_flags(dev, flags);
3524 }
3525 
3526 static int __dev_set_promiscuity(struct net_device *dev, int inc)
3527 {
3528 	unsigned short old_flags = dev->flags;
3529 	uid_t uid;
3530 	gid_t gid;
3531 
3532 	ASSERT_RTNL();
3533 
3534 	dev->flags |= IFF_PROMISC;
3535 	dev->promiscuity += inc;
3536 	if (dev->promiscuity == 0) {
3537 		/*
3538 		 * Avoid overflow.
3539 		 * If inc causes overflow, untouch promisc and return error.
3540 		 */
3541 		if (inc < 0)
3542 			dev->flags &= ~IFF_PROMISC;
3543 		else {
3544 			dev->promiscuity -= inc;
3545 			printk(KERN_WARNING "%s: promiscuity touches roof, "
3546 				"set promiscuity failed, promiscuity feature "
3547 				"of device might be broken.\n", dev->name);
3548 			return -EOVERFLOW;
3549 		}
3550 	}
3551 	if (dev->flags != old_flags) {
3552 		printk(KERN_INFO "device %s %s promiscuous mode\n",
3553 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
3554 							       "left");
3555 		if (audit_enabled) {
3556 			current_uid_gid(&uid, &gid);
3557 			audit_log(current->audit_context, GFP_ATOMIC,
3558 				AUDIT_ANOM_PROMISCUOUS,
3559 				"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
3560 				dev->name, (dev->flags & IFF_PROMISC),
3561 				(old_flags & IFF_PROMISC),
3562 				audit_get_loginuid(current),
3563 				uid, gid,
3564 				audit_get_sessionid(current));
3565 		}
3566 
3567 		dev_change_rx_flags(dev, IFF_PROMISC);
3568 	}
3569 	return 0;
3570 }
3571 
3572 /**
3573  *	dev_set_promiscuity	- update promiscuity count on a device
3574  *	@dev: device
3575  *	@inc: modifier
3576  *
3577  *	Add or remove promiscuity from a device. While the count in the device
3578  *	remains above zero the interface remains promiscuous. Once it hits zero
3579  *	the device reverts back to normal filtering operation. A negative inc
3580  *	value is used to drop promiscuity on the device.
3581  *	Return 0 if successful or a negative errno code on error.
3582  */
3583 int dev_set_promiscuity(struct net_device *dev, int inc)
3584 {
3585 	unsigned short old_flags = dev->flags;
3586 	int err;
3587 
3588 	err = __dev_set_promiscuity(dev, inc);
3589 	if (err < 0)
3590 		return err;
3591 	if (dev->flags != old_flags)
3592 		dev_set_rx_mode(dev);
3593 	return err;
3594 }
3595 EXPORT_SYMBOL(dev_set_promiscuity);
3596 
3597 /**
3598  *	dev_set_allmulti	- update allmulti count on a device
3599  *	@dev: device
3600  *	@inc: modifier
3601  *
3602  *	Add or remove reception of all multicast frames to a device. While the
3603  *	count in the device remains above zero the interface remains listening
3604  *	to all interfaces. Once it hits zero the device reverts back to normal
3605  *	filtering operation. A negative @inc value is used to drop the counter
3606  *	when releasing a resource needing all multicasts.
3607  *	Return 0 if successful or a negative errno code on error.
3608  */
3609 
3610 int dev_set_allmulti(struct net_device *dev, int inc)
3611 {
3612 	unsigned short old_flags = dev->flags;
3613 
3614 	ASSERT_RTNL();
3615 
3616 	dev->flags |= IFF_ALLMULTI;
3617 	dev->allmulti += inc;
3618 	if (dev->allmulti == 0) {
3619 		/*
3620 		 * Avoid overflow.
3621 		 * If inc causes overflow, untouch allmulti and return error.
3622 		 */
3623 		if (inc < 0)
3624 			dev->flags &= ~IFF_ALLMULTI;
3625 		else {
3626 			dev->allmulti -= inc;
3627 			printk(KERN_WARNING "%s: allmulti touches roof, "
3628 				"set allmulti failed, allmulti feature of "
3629 				"device might be broken.\n", dev->name);
3630 			return -EOVERFLOW;
3631 		}
3632 	}
3633 	if (dev->flags ^ old_flags) {
3634 		dev_change_rx_flags(dev, IFF_ALLMULTI);
3635 		dev_set_rx_mode(dev);
3636 	}
3637 	return 0;
3638 }
3639 EXPORT_SYMBOL(dev_set_allmulti);
3640 
3641 /*
3642  *	Upload unicast and multicast address lists to device and
3643  *	configure RX filtering. When the device doesn't support unicast
3644  *	filtering it is put in promiscuous mode while unicast addresses
3645  *	are present.
3646  */
3647 void __dev_set_rx_mode(struct net_device *dev)
3648 {
3649 	const struct net_device_ops *ops = dev->netdev_ops;
3650 
3651 	/* dev_open will call this function so the list will stay sane. */
3652 	if (!(dev->flags&IFF_UP))
3653 		return;
3654 
3655 	if (!netif_device_present(dev))
3656 		return;
3657 
3658 	if (ops->ndo_set_rx_mode)
3659 		ops->ndo_set_rx_mode(dev);
3660 	else {
3661 		/* Unicast addresses changes may only happen under the rtnl,
3662 		 * therefore calling __dev_set_promiscuity here is safe.
3663 		 */
3664 		if (dev->uc.count > 0 && !dev->uc_promisc) {
3665 			__dev_set_promiscuity(dev, 1);
3666 			dev->uc_promisc = 1;
3667 		} else if (dev->uc.count == 0 && dev->uc_promisc) {
3668 			__dev_set_promiscuity(dev, -1);
3669 			dev->uc_promisc = 0;
3670 		}
3671 
3672 		if (ops->ndo_set_multicast_list)
3673 			ops->ndo_set_multicast_list(dev);
3674 	}
3675 }
3676 
3677 void dev_set_rx_mode(struct net_device *dev)
3678 {
3679 	netif_addr_lock_bh(dev);
3680 	__dev_set_rx_mode(dev);
3681 	netif_addr_unlock_bh(dev);
3682 }
3683 
3684 /* hw addresses list handling functions */
3685 
3686 static int __hw_addr_add(struct netdev_hw_addr_list *list, unsigned char *addr,
3687 			 int addr_len, unsigned char addr_type)
3688 {
3689 	struct netdev_hw_addr *ha;
3690 	int alloc_size;
3691 
3692 	if (addr_len > MAX_ADDR_LEN)
3693 		return -EINVAL;
3694 
3695 	list_for_each_entry(ha, &list->list, list) {
3696 		if (!memcmp(ha->addr, addr, addr_len) &&
3697 		    ha->type == addr_type) {
3698 			ha->refcount++;
3699 			return 0;
3700 		}
3701 	}
3702 
3703 
3704 	alloc_size = sizeof(*ha);
3705 	if (alloc_size < L1_CACHE_BYTES)
3706 		alloc_size = L1_CACHE_BYTES;
3707 	ha = kmalloc(alloc_size, GFP_ATOMIC);
3708 	if (!ha)
3709 		return -ENOMEM;
3710 	memcpy(ha->addr, addr, addr_len);
3711 	ha->type = addr_type;
3712 	ha->refcount = 1;
3713 	ha->synced = false;
3714 	list_add_tail_rcu(&ha->list, &list->list);
3715 	list->count++;
3716 	return 0;
3717 }
3718 
3719 static void ha_rcu_free(struct rcu_head *head)
3720 {
3721 	struct netdev_hw_addr *ha;
3722 
3723 	ha = container_of(head, struct netdev_hw_addr, rcu_head);
3724 	kfree(ha);
3725 }
3726 
3727 static int __hw_addr_del(struct netdev_hw_addr_list *list, unsigned char *addr,
3728 			 int addr_len, unsigned char addr_type)
3729 {
3730 	struct netdev_hw_addr *ha;
3731 
3732 	list_for_each_entry(ha, &list->list, list) {
3733 		if (!memcmp(ha->addr, addr, addr_len) &&
3734 		    (ha->type == addr_type || !addr_type)) {
3735 			if (--ha->refcount)
3736 				return 0;
3737 			list_del_rcu(&ha->list);
3738 			call_rcu(&ha->rcu_head, ha_rcu_free);
3739 			list->count--;
3740 			return 0;
3741 		}
3742 	}
3743 	return -ENOENT;
3744 }
3745 
3746 static int __hw_addr_add_multiple(struct netdev_hw_addr_list *to_list,
3747 				  struct netdev_hw_addr_list *from_list,
3748 				  int addr_len,
3749 				  unsigned char addr_type)
3750 {
3751 	int err;
3752 	struct netdev_hw_addr *ha, *ha2;
3753 	unsigned char type;
3754 
3755 	list_for_each_entry(ha, &from_list->list, list) {
3756 		type = addr_type ? addr_type : ha->type;
3757 		err = __hw_addr_add(to_list, ha->addr, addr_len, type);
3758 		if (err)
3759 			goto unroll;
3760 	}
3761 	return 0;
3762 
3763 unroll:
3764 	list_for_each_entry(ha2, &from_list->list, list) {
3765 		if (ha2 == ha)
3766 			break;
3767 		type = addr_type ? addr_type : ha2->type;
3768 		__hw_addr_del(to_list, ha2->addr, addr_len, type);
3769 	}
3770 	return err;
3771 }
3772 
3773 static void __hw_addr_del_multiple(struct netdev_hw_addr_list *to_list,
3774 				   struct netdev_hw_addr_list *from_list,
3775 				   int addr_len,
3776 				   unsigned char addr_type)
3777 {
3778 	struct netdev_hw_addr *ha;
3779 	unsigned char type;
3780 
3781 	list_for_each_entry(ha, &from_list->list, list) {
3782 		type = addr_type ? addr_type : ha->type;
3783 		__hw_addr_del(to_list, ha->addr, addr_len, addr_type);
3784 	}
3785 }
3786 
3787 static int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
3788 			  struct netdev_hw_addr_list *from_list,
3789 			  int addr_len)
3790 {
3791 	int err = 0;
3792 	struct netdev_hw_addr *ha, *tmp;
3793 
3794 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
3795 		if (!ha->synced) {
3796 			err = __hw_addr_add(to_list, ha->addr,
3797 					    addr_len, ha->type);
3798 			if (err)
3799 				break;
3800 			ha->synced = true;
3801 			ha->refcount++;
3802 		} else if (ha->refcount == 1) {
3803 			__hw_addr_del(to_list, ha->addr, addr_len, ha->type);
3804 			__hw_addr_del(from_list, ha->addr, addr_len, ha->type);
3805 		}
3806 	}
3807 	return err;
3808 }
3809 
3810 static void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
3811 			     struct netdev_hw_addr_list *from_list,
3812 			     int addr_len)
3813 {
3814 	struct netdev_hw_addr *ha, *tmp;
3815 
3816 	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
3817 		if (ha->synced) {
3818 			__hw_addr_del(to_list, ha->addr,
3819 				      addr_len, ha->type);
3820 			ha->synced = false;
3821 			__hw_addr_del(from_list, ha->addr,
3822 				      addr_len, ha->type);
3823 		}
3824 	}
3825 }
3826 
3827 static void __hw_addr_flush(struct netdev_hw_addr_list *list)
3828 {
3829 	struct netdev_hw_addr *ha, *tmp;
3830 
3831 	list_for_each_entry_safe(ha, tmp, &list->list, list) {
3832 		list_del_rcu(&ha->list);
3833 		call_rcu(&ha->rcu_head, ha_rcu_free);
3834 	}
3835 	list->count = 0;
3836 }
3837 
3838 static void __hw_addr_init(struct netdev_hw_addr_list *list)
3839 {
3840 	INIT_LIST_HEAD(&list->list);
3841 	list->count = 0;
3842 }
3843 
3844 /* Device addresses handling functions */
3845 
3846 static void dev_addr_flush(struct net_device *dev)
3847 {
3848 	/* rtnl_mutex must be held here */
3849 
3850 	__hw_addr_flush(&dev->dev_addrs);
3851 	dev->dev_addr = NULL;
3852 }
3853 
3854 static int dev_addr_init(struct net_device *dev)
3855 {
3856 	unsigned char addr[MAX_ADDR_LEN];
3857 	struct netdev_hw_addr *ha;
3858 	int err;
3859 
3860 	/* rtnl_mutex must be held here */
3861 
3862 	__hw_addr_init(&dev->dev_addrs);
3863 	memset(addr, 0, sizeof(addr));
3864 	err = __hw_addr_add(&dev->dev_addrs, addr, sizeof(addr),
3865 			    NETDEV_HW_ADDR_T_LAN);
3866 	if (!err) {
3867 		/*
3868 		 * Get the first (previously created) address from the list
3869 		 * and set dev_addr pointer to this location.
3870 		 */
3871 		ha = list_first_entry(&dev->dev_addrs.list,
3872 				      struct netdev_hw_addr, list);
3873 		dev->dev_addr = ha->addr;
3874 	}
3875 	return err;
3876 }
3877 
3878 /**
3879  *	dev_addr_add	- Add a device address
3880  *	@dev: device
3881  *	@addr: address to add
3882  *	@addr_type: address type
3883  *
3884  *	Add a device address to the device or increase the reference count if
3885  *	it already exists.
3886  *
3887  *	The caller must hold the rtnl_mutex.
3888  */
3889 int dev_addr_add(struct net_device *dev, unsigned char *addr,
3890 		 unsigned char addr_type)
3891 {
3892 	int err;
3893 
3894 	ASSERT_RTNL();
3895 
3896 	err = __hw_addr_add(&dev->dev_addrs, addr, dev->addr_len, addr_type);
3897 	if (!err)
3898 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
3899 	return err;
3900 }
3901 EXPORT_SYMBOL(dev_addr_add);
3902 
3903 /**
3904  *	dev_addr_del	- Release a device address.
3905  *	@dev: device
3906  *	@addr: address to delete
3907  *	@addr_type: address type
3908  *
3909  *	Release reference to a device address and remove it from the device
3910  *	if the reference count drops to zero.
3911  *
3912  *	The caller must hold the rtnl_mutex.
3913  */
3914 int dev_addr_del(struct net_device *dev, unsigned char *addr,
3915 		 unsigned char addr_type)
3916 {
3917 	int err;
3918 	struct netdev_hw_addr *ha;
3919 
3920 	ASSERT_RTNL();
3921 
3922 	/*
3923 	 * We can not remove the first address from the list because
3924 	 * dev->dev_addr points to that.
3925 	 */
3926 	ha = list_first_entry(&dev->dev_addrs.list,
3927 			      struct netdev_hw_addr, list);
3928 	if (ha->addr == dev->dev_addr && ha->refcount == 1)
3929 		return -ENOENT;
3930 
3931 	err = __hw_addr_del(&dev->dev_addrs, addr, dev->addr_len,
3932 			    addr_type);
3933 	if (!err)
3934 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
3935 	return err;
3936 }
3937 EXPORT_SYMBOL(dev_addr_del);
3938 
3939 /**
3940  *	dev_addr_add_multiple	- Add device addresses from another device
3941  *	@to_dev: device to which addresses will be added
3942  *	@from_dev: device from which addresses will be added
3943  *	@addr_type: address type - 0 means type will be used from from_dev
3944  *
3945  *	Add device addresses of the one device to another.
3946  **
3947  *	The caller must hold the rtnl_mutex.
3948  */
3949 int dev_addr_add_multiple(struct net_device *to_dev,
3950 			  struct net_device *from_dev,
3951 			  unsigned char addr_type)
3952 {
3953 	int err;
3954 
3955 	ASSERT_RTNL();
3956 
3957 	if (from_dev->addr_len != to_dev->addr_len)
3958 		return -EINVAL;
3959 	err = __hw_addr_add_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
3960 				     to_dev->addr_len, addr_type);
3961 	if (!err)
3962 		call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
3963 	return err;
3964 }
3965 EXPORT_SYMBOL(dev_addr_add_multiple);
3966 
3967 /**
3968  *	dev_addr_del_multiple	- Delete device addresses by another device
3969  *	@to_dev: device where the addresses will be deleted
3970  *	@from_dev: device by which addresses the addresses will be deleted
3971  *	@addr_type: address type - 0 means type will used from from_dev
3972  *
3973  *	Deletes addresses in to device by the list of addresses in from device.
3974  *
3975  *	The caller must hold the rtnl_mutex.
3976  */
3977 int dev_addr_del_multiple(struct net_device *to_dev,
3978 			  struct net_device *from_dev,
3979 			  unsigned char addr_type)
3980 {
3981 	ASSERT_RTNL();
3982 
3983 	if (from_dev->addr_len != to_dev->addr_len)
3984 		return -EINVAL;
3985 	__hw_addr_del_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
3986 			       to_dev->addr_len, addr_type);
3987 	call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
3988 	return 0;
3989 }
3990 EXPORT_SYMBOL(dev_addr_del_multiple);
3991 
3992 /* multicast addresses handling functions */
3993 
3994 int __dev_addr_delete(struct dev_addr_list **list, int *count,
3995 		      void *addr, int alen, int glbl)
3996 {
3997 	struct dev_addr_list *da;
3998 
3999 	for (; (da = *list) != NULL; list = &da->next) {
4000 		if (memcmp(da->da_addr, addr, da->da_addrlen) == 0 &&
4001 		    alen == da->da_addrlen) {
4002 			if (glbl) {
4003 				int old_glbl = da->da_gusers;
4004 				da->da_gusers = 0;
4005 				if (old_glbl == 0)
4006 					break;
4007 			}
4008 			if (--da->da_users)
4009 				return 0;
4010 
4011 			*list = da->next;
4012 			kfree(da);
4013 			(*count)--;
4014 			return 0;
4015 		}
4016 	}
4017 	return -ENOENT;
4018 }
4019 
4020 int __dev_addr_add(struct dev_addr_list **list, int *count,
4021 		   void *addr, int alen, int glbl)
4022 {
4023 	struct dev_addr_list *da;
4024 
4025 	for (da = *list; da != NULL; da = da->next) {
4026 		if (memcmp(da->da_addr, addr, da->da_addrlen) == 0 &&
4027 		    da->da_addrlen == alen) {
4028 			if (glbl) {
4029 				int old_glbl = da->da_gusers;
4030 				da->da_gusers = 1;
4031 				if (old_glbl)
4032 					return 0;
4033 			}
4034 			da->da_users++;
4035 			return 0;
4036 		}
4037 	}
4038 
4039 	da = kzalloc(sizeof(*da), GFP_ATOMIC);
4040 	if (da == NULL)
4041 		return -ENOMEM;
4042 	memcpy(da->da_addr, addr, alen);
4043 	da->da_addrlen = alen;
4044 	da->da_users = 1;
4045 	da->da_gusers = glbl ? 1 : 0;
4046 	da->next = *list;
4047 	*list = da;
4048 	(*count)++;
4049 	return 0;
4050 }
4051 
4052 /**
4053  *	dev_unicast_delete	- Release secondary unicast address.
4054  *	@dev: device
4055  *	@addr: address to delete
4056  *
4057  *	Release reference to a secondary unicast address and remove it
4058  *	from the device if the reference count drops to zero.
4059  *
4060  * 	The caller must hold the rtnl_mutex.
4061  */
4062 int dev_unicast_delete(struct net_device *dev, void *addr)
4063 {
4064 	int err;
4065 
4066 	ASSERT_RTNL();
4067 
4068 	netif_addr_lock_bh(dev);
4069 	err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
4070 			    NETDEV_HW_ADDR_T_UNICAST);
4071 	if (!err)
4072 		__dev_set_rx_mode(dev);
4073 	netif_addr_unlock_bh(dev);
4074 	return err;
4075 }
4076 EXPORT_SYMBOL(dev_unicast_delete);
4077 
4078 /**
4079  *	dev_unicast_add		- add a secondary unicast address
4080  *	@dev: device
4081  *	@addr: address to add
4082  *
4083  *	Add a secondary unicast address to the device or increase
4084  *	the reference count if it already exists.
4085  *
4086  *	The caller must hold the rtnl_mutex.
4087  */
4088 int dev_unicast_add(struct net_device *dev, void *addr)
4089 {
4090 	int err;
4091 
4092 	ASSERT_RTNL();
4093 
4094 	netif_addr_lock_bh(dev);
4095 	err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
4096 			    NETDEV_HW_ADDR_T_UNICAST);
4097 	if (!err)
4098 		__dev_set_rx_mode(dev);
4099 	netif_addr_unlock_bh(dev);
4100 	return err;
4101 }
4102 EXPORT_SYMBOL(dev_unicast_add);
4103 
4104 int __dev_addr_sync(struct dev_addr_list **to, int *to_count,
4105 		    struct dev_addr_list **from, int *from_count)
4106 {
4107 	struct dev_addr_list *da, *next;
4108 	int err = 0;
4109 
4110 	da = *from;
4111 	while (da != NULL) {
4112 		next = da->next;
4113 		if (!da->da_synced) {
4114 			err = __dev_addr_add(to, to_count,
4115 					     da->da_addr, da->da_addrlen, 0);
4116 			if (err < 0)
4117 				break;
4118 			da->da_synced = 1;
4119 			da->da_users++;
4120 		} else if (da->da_users == 1) {
4121 			__dev_addr_delete(to, to_count,
4122 					  da->da_addr, da->da_addrlen, 0);
4123 			__dev_addr_delete(from, from_count,
4124 					  da->da_addr, da->da_addrlen, 0);
4125 		}
4126 		da = next;
4127 	}
4128 	return err;
4129 }
4130 EXPORT_SYMBOL_GPL(__dev_addr_sync);
4131 
4132 void __dev_addr_unsync(struct dev_addr_list **to, int *to_count,
4133 		       struct dev_addr_list **from, int *from_count)
4134 {
4135 	struct dev_addr_list *da, *next;
4136 
4137 	da = *from;
4138 	while (da != NULL) {
4139 		next = da->next;
4140 		if (da->da_synced) {
4141 			__dev_addr_delete(to, to_count,
4142 					  da->da_addr, da->da_addrlen, 0);
4143 			da->da_synced = 0;
4144 			__dev_addr_delete(from, from_count,
4145 					  da->da_addr, da->da_addrlen, 0);
4146 		}
4147 		da = next;
4148 	}
4149 }
4150 EXPORT_SYMBOL_GPL(__dev_addr_unsync);
4151 
4152 /**
4153  *	dev_unicast_sync - Synchronize device's unicast list to another device
4154  *	@to: destination device
4155  *	@from: source device
4156  *
4157  *	Add newly added addresses to the destination device and release
4158  *	addresses that have no users left. The source device must be
4159  *	locked by netif_tx_lock_bh.
4160  *
4161  *	This function is intended to be called from the dev->set_rx_mode
4162  *	function of layered software devices.
4163  */
4164 int dev_unicast_sync(struct net_device *to, struct net_device *from)
4165 {
4166 	int err = 0;
4167 
4168 	if (to->addr_len != from->addr_len)
4169 		return -EINVAL;
4170 
4171 	netif_addr_lock_bh(to);
4172 	err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
4173 	if (!err)
4174 		__dev_set_rx_mode(to);
4175 	netif_addr_unlock_bh(to);
4176 	return err;
4177 }
4178 EXPORT_SYMBOL(dev_unicast_sync);
4179 
4180 /**
4181  *	dev_unicast_unsync - Remove synchronized addresses from the destination device
4182  *	@to: destination device
4183  *	@from: source device
4184  *
4185  *	Remove all addresses that were added to the destination device by
4186  *	dev_unicast_sync(). This function is intended to be called from the
4187  *	dev->stop function of layered software devices.
4188  */
4189 void dev_unicast_unsync(struct net_device *to, struct net_device *from)
4190 {
4191 	if (to->addr_len != from->addr_len)
4192 		return;
4193 
4194 	netif_addr_lock_bh(from);
4195 	netif_addr_lock(to);
4196 	__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
4197 	__dev_set_rx_mode(to);
4198 	netif_addr_unlock(to);
4199 	netif_addr_unlock_bh(from);
4200 }
4201 EXPORT_SYMBOL(dev_unicast_unsync);
4202 
4203 static void dev_unicast_flush(struct net_device *dev)
4204 {
4205 	netif_addr_lock_bh(dev);
4206 	__hw_addr_flush(&dev->uc);
4207 	netif_addr_unlock_bh(dev);
4208 }
4209 
4210 static void dev_unicast_init(struct net_device *dev)
4211 {
4212 	__hw_addr_init(&dev->uc);
4213 }
4214 
4215 
4216 static void __dev_addr_discard(struct dev_addr_list **list)
4217 {
4218 	struct dev_addr_list *tmp;
4219 
4220 	while (*list != NULL) {
4221 		tmp = *list;
4222 		*list = tmp->next;
4223 		if (tmp->da_users > tmp->da_gusers)
4224 			printk("__dev_addr_discard: address leakage! "
4225 			       "da_users=%d\n", tmp->da_users);
4226 		kfree(tmp);
4227 	}
4228 }
4229 
4230 static void dev_addr_discard(struct net_device *dev)
4231 {
4232 	netif_addr_lock_bh(dev);
4233 
4234 	__dev_addr_discard(&dev->mc_list);
4235 	dev->mc_count = 0;
4236 
4237 	netif_addr_unlock_bh(dev);
4238 }
4239 
4240 /**
4241  *	dev_get_flags - get flags reported to userspace
4242  *	@dev: device
4243  *
4244  *	Get the combination of flag bits exported through APIs to userspace.
4245  */
4246 unsigned dev_get_flags(const struct net_device *dev)
4247 {
4248 	unsigned flags;
4249 
4250 	flags = (dev->flags & ~(IFF_PROMISC |
4251 				IFF_ALLMULTI |
4252 				IFF_RUNNING |
4253 				IFF_LOWER_UP |
4254 				IFF_DORMANT)) |
4255 		(dev->gflags & (IFF_PROMISC |
4256 				IFF_ALLMULTI));
4257 
4258 	if (netif_running(dev)) {
4259 		if (netif_oper_up(dev))
4260 			flags |= IFF_RUNNING;
4261 		if (netif_carrier_ok(dev))
4262 			flags |= IFF_LOWER_UP;
4263 		if (netif_dormant(dev))
4264 			flags |= IFF_DORMANT;
4265 	}
4266 
4267 	return flags;
4268 }
4269 EXPORT_SYMBOL(dev_get_flags);
4270 
4271 /**
4272  *	dev_change_flags - change device settings
4273  *	@dev: device
4274  *	@flags: device state flags
4275  *
4276  *	Change settings on device based state flags. The flags are
4277  *	in the userspace exported format.
4278  */
4279 int dev_change_flags(struct net_device *dev, unsigned flags)
4280 {
4281 	int ret, changes;
4282 	int old_flags = dev->flags;
4283 
4284 	ASSERT_RTNL();
4285 
4286 	/*
4287 	 *	Set the flags on our device.
4288 	 */
4289 
4290 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
4291 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
4292 			       IFF_AUTOMEDIA)) |
4293 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
4294 				    IFF_ALLMULTI));
4295 
4296 	/*
4297 	 *	Load in the correct multicast list now the flags have changed.
4298 	 */
4299 
4300 	if ((old_flags ^ flags) & IFF_MULTICAST)
4301 		dev_change_rx_flags(dev, IFF_MULTICAST);
4302 
4303 	dev_set_rx_mode(dev);
4304 
4305 	/*
4306 	 *	Have we downed the interface. We handle IFF_UP ourselves
4307 	 *	according to user attempts to set it, rather than blindly
4308 	 *	setting it.
4309 	 */
4310 
4311 	ret = 0;
4312 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
4313 		ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);
4314 
4315 		if (!ret)
4316 			dev_set_rx_mode(dev);
4317 	}
4318 
4319 	if (dev->flags & IFF_UP &&
4320 	    ((old_flags ^ dev->flags) & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI |
4321 					  IFF_VOLATILE)))
4322 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
4323 
4324 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
4325 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
4326 
4327 		dev->gflags ^= IFF_PROMISC;
4328 		dev_set_promiscuity(dev, inc);
4329 	}
4330 
4331 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
4332 	   is important. Some (broken) drivers set IFF_PROMISC, when
4333 	   IFF_ALLMULTI is requested not asking us and not reporting.
4334 	 */
4335 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
4336 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
4337 
4338 		dev->gflags ^= IFF_ALLMULTI;
4339 		dev_set_allmulti(dev, inc);
4340 	}
4341 
4342 	/* Exclude state transition flags, already notified */
4343 	changes = (old_flags ^ dev->flags) & ~(IFF_UP | IFF_RUNNING);
4344 	if (changes)
4345 		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
4346 
4347 	return ret;
4348 }
4349 EXPORT_SYMBOL(dev_change_flags);
4350 
4351 /**
4352  *	dev_set_mtu - Change maximum transfer unit
4353  *	@dev: device
4354  *	@new_mtu: new transfer unit
4355  *
4356  *	Change the maximum transfer size of the network device.
4357  */
4358 int dev_set_mtu(struct net_device *dev, int new_mtu)
4359 {
4360 	const struct net_device_ops *ops = dev->netdev_ops;
4361 	int err;
4362 
4363 	if (new_mtu == dev->mtu)
4364 		return 0;
4365 
4366 	/*	MTU must be positive.	 */
4367 	if (new_mtu < 0)
4368 		return -EINVAL;
4369 
4370 	if (!netif_device_present(dev))
4371 		return -ENODEV;
4372 
4373 	err = 0;
4374 	if (ops->ndo_change_mtu)
4375 		err = ops->ndo_change_mtu(dev, new_mtu);
4376 	else
4377 		dev->mtu = new_mtu;
4378 
4379 	if (!err && dev->flags & IFF_UP)
4380 		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
4381 	return err;
4382 }
4383 EXPORT_SYMBOL(dev_set_mtu);
4384 
4385 /**
4386  *	dev_set_mac_address - Change Media Access Control Address
4387  *	@dev: device
4388  *	@sa: new address
4389  *
4390  *	Change the hardware (MAC) address of the device
4391  */
4392 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
4393 {
4394 	const struct net_device_ops *ops = dev->netdev_ops;
4395 	int err;
4396 
4397 	if (!ops->ndo_set_mac_address)
4398 		return -EOPNOTSUPP;
4399 	if (sa->sa_family != dev->type)
4400 		return -EINVAL;
4401 	if (!netif_device_present(dev))
4402 		return -ENODEV;
4403 	err = ops->ndo_set_mac_address(dev, sa);
4404 	if (!err)
4405 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4406 	return err;
4407 }
4408 EXPORT_SYMBOL(dev_set_mac_address);
4409 
4410 /*
4411  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
4412  */
4413 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
4414 {
4415 	int err;
4416 	struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
4417 
4418 	if (!dev)
4419 		return -ENODEV;
4420 
4421 	switch (cmd) {
4422 	case SIOCGIFFLAGS:	/* Get interface flags */
4423 		ifr->ifr_flags = (short) dev_get_flags(dev);
4424 		return 0;
4425 
4426 	case SIOCGIFMETRIC:	/* Get the metric on the interface
4427 				   (currently unused) */
4428 		ifr->ifr_metric = 0;
4429 		return 0;
4430 
4431 	case SIOCGIFMTU:	/* Get the MTU of a device */
4432 		ifr->ifr_mtu = dev->mtu;
4433 		return 0;
4434 
4435 	case SIOCGIFHWADDR:
4436 		if (!dev->addr_len)
4437 			memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
4438 		else
4439 			memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
4440 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4441 		ifr->ifr_hwaddr.sa_family = dev->type;
4442 		return 0;
4443 
4444 	case SIOCGIFSLAVE:
4445 		err = -EINVAL;
4446 		break;
4447 
4448 	case SIOCGIFMAP:
4449 		ifr->ifr_map.mem_start = dev->mem_start;
4450 		ifr->ifr_map.mem_end   = dev->mem_end;
4451 		ifr->ifr_map.base_addr = dev->base_addr;
4452 		ifr->ifr_map.irq       = dev->irq;
4453 		ifr->ifr_map.dma       = dev->dma;
4454 		ifr->ifr_map.port      = dev->if_port;
4455 		return 0;
4456 
4457 	case SIOCGIFINDEX:
4458 		ifr->ifr_ifindex = dev->ifindex;
4459 		return 0;
4460 
4461 	case SIOCGIFTXQLEN:
4462 		ifr->ifr_qlen = dev->tx_queue_len;
4463 		return 0;
4464 
4465 	default:
4466 		/* dev_ioctl() should ensure this case
4467 		 * is never reached
4468 		 */
4469 		WARN_ON(1);
4470 		err = -EINVAL;
4471 		break;
4472 
4473 	}
4474 	return err;
4475 }
4476 
4477 /*
4478  *	Perform the SIOCxIFxxx calls, inside rtnl_lock()
4479  */
4480 static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
4481 {
4482 	int err;
4483 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
4484 	const struct net_device_ops *ops;
4485 
4486 	if (!dev)
4487 		return -ENODEV;
4488 
4489 	ops = dev->netdev_ops;
4490 
4491 	switch (cmd) {
4492 	case SIOCSIFFLAGS:	/* Set interface flags */
4493 		return dev_change_flags(dev, ifr->ifr_flags);
4494 
4495 	case SIOCSIFMETRIC:	/* Set the metric on the interface
4496 				   (currently unused) */
4497 		return -EOPNOTSUPP;
4498 
4499 	case SIOCSIFMTU:	/* Set the MTU of a device */
4500 		return dev_set_mtu(dev, ifr->ifr_mtu);
4501 
4502 	case SIOCSIFHWADDR:
4503 		return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
4504 
4505 	case SIOCSIFHWBROADCAST:
4506 		if (ifr->ifr_hwaddr.sa_family != dev->type)
4507 			return -EINVAL;
4508 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
4509 		       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4510 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4511 		return 0;
4512 
4513 	case SIOCSIFMAP:
4514 		if (ops->ndo_set_config) {
4515 			if (!netif_device_present(dev))
4516 				return -ENODEV;
4517 			return ops->ndo_set_config(dev, &ifr->ifr_map);
4518 		}
4519 		return -EOPNOTSUPP;
4520 
4521 	case SIOCADDMULTI:
4522 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4523 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4524 			return -EINVAL;
4525 		if (!netif_device_present(dev))
4526 			return -ENODEV;
4527 		return dev_mc_add(dev, ifr->ifr_hwaddr.sa_data,
4528 				  dev->addr_len, 1);
4529 
4530 	case SIOCDELMULTI:
4531 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4532 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4533 			return -EINVAL;
4534 		if (!netif_device_present(dev))
4535 			return -ENODEV;
4536 		return dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data,
4537 				     dev->addr_len, 1);
4538 
4539 	case SIOCSIFTXQLEN:
4540 		if (ifr->ifr_qlen < 0)
4541 			return -EINVAL;
4542 		dev->tx_queue_len = ifr->ifr_qlen;
4543 		return 0;
4544 
4545 	case SIOCSIFNAME:
4546 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
4547 		return dev_change_name(dev, ifr->ifr_newname);
4548 
4549 	/*
4550 	 *	Unknown or private ioctl
4551 	 */
4552 	default:
4553 		if ((cmd >= SIOCDEVPRIVATE &&
4554 		    cmd <= SIOCDEVPRIVATE + 15) ||
4555 		    cmd == SIOCBONDENSLAVE ||
4556 		    cmd == SIOCBONDRELEASE ||
4557 		    cmd == SIOCBONDSETHWADDR ||
4558 		    cmd == SIOCBONDSLAVEINFOQUERY ||
4559 		    cmd == SIOCBONDINFOQUERY ||
4560 		    cmd == SIOCBONDCHANGEACTIVE ||
4561 		    cmd == SIOCGMIIPHY ||
4562 		    cmd == SIOCGMIIREG ||
4563 		    cmd == SIOCSMIIREG ||
4564 		    cmd == SIOCBRADDIF ||
4565 		    cmd == SIOCBRDELIF ||
4566 		    cmd == SIOCSHWTSTAMP ||
4567 		    cmd == SIOCWANDEV) {
4568 			err = -EOPNOTSUPP;
4569 			if (ops->ndo_do_ioctl) {
4570 				if (netif_device_present(dev))
4571 					err = ops->ndo_do_ioctl(dev, ifr, cmd);
4572 				else
4573 					err = -ENODEV;
4574 			}
4575 		} else
4576 			err = -EINVAL;
4577 
4578 	}
4579 	return err;
4580 }
4581 
4582 /*
4583  *	This function handles all "interface"-type I/O control requests. The actual
4584  *	'doing' part of this is dev_ifsioc above.
4585  */
4586 
4587 /**
4588  *	dev_ioctl	-	network device ioctl
4589  *	@net: the applicable net namespace
4590  *	@cmd: command to issue
4591  *	@arg: pointer to a struct ifreq in user space
4592  *
4593  *	Issue ioctl functions to devices. This is normally called by the
4594  *	user space syscall interfaces but can sometimes be useful for
4595  *	other purposes. The return value is the return from the syscall if
4596  *	positive or a negative errno code on error.
4597  */
4598 
4599 int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
4600 {
4601 	struct ifreq ifr;
4602 	int ret;
4603 	char *colon;
4604 
4605 	/* One special case: SIOCGIFCONF takes ifconf argument
4606 	   and requires shared lock, because it sleeps writing
4607 	   to user space.
4608 	 */
4609 
4610 	if (cmd == SIOCGIFCONF) {
4611 		rtnl_lock();
4612 		ret = dev_ifconf(net, (char __user *) arg);
4613 		rtnl_unlock();
4614 		return ret;
4615 	}
4616 	if (cmd == SIOCGIFNAME)
4617 		return dev_ifname(net, (struct ifreq __user *)arg);
4618 
4619 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
4620 		return -EFAULT;
4621 
4622 	ifr.ifr_name[IFNAMSIZ-1] = 0;
4623 
4624 	colon = strchr(ifr.ifr_name, ':');
4625 	if (colon)
4626 		*colon = 0;
4627 
4628 	/*
4629 	 *	See which interface the caller is talking about.
4630 	 */
4631 
4632 	switch (cmd) {
4633 	/*
4634 	 *	These ioctl calls:
4635 	 *	- can be done by all.
4636 	 *	- atomic and do not require locking.
4637 	 *	- return a value
4638 	 */
4639 	case SIOCGIFFLAGS:
4640 	case SIOCGIFMETRIC:
4641 	case SIOCGIFMTU:
4642 	case SIOCGIFHWADDR:
4643 	case SIOCGIFSLAVE:
4644 	case SIOCGIFMAP:
4645 	case SIOCGIFINDEX:
4646 	case SIOCGIFTXQLEN:
4647 		dev_load(net, ifr.ifr_name);
4648 		rcu_read_lock();
4649 		ret = dev_ifsioc_locked(net, &ifr, cmd);
4650 		rcu_read_unlock();
4651 		if (!ret) {
4652 			if (colon)
4653 				*colon = ':';
4654 			if (copy_to_user(arg, &ifr,
4655 					 sizeof(struct ifreq)))
4656 				ret = -EFAULT;
4657 		}
4658 		return ret;
4659 
4660 	case SIOCETHTOOL:
4661 		dev_load(net, ifr.ifr_name);
4662 		rtnl_lock();
4663 		ret = dev_ethtool(net, &ifr);
4664 		rtnl_unlock();
4665 		if (!ret) {
4666 			if (colon)
4667 				*colon = ':';
4668 			if (copy_to_user(arg, &ifr,
4669 					 sizeof(struct ifreq)))
4670 				ret = -EFAULT;
4671 		}
4672 		return ret;
4673 
4674 	/*
4675 	 *	These ioctl calls:
4676 	 *	- require superuser power.
4677 	 *	- require strict serialization.
4678 	 *	- return a value
4679 	 */
4680 	case SIOCGMIIPHY:
4681 	case SIOCGMIIREG:
4682 	case SIOCSIFNAME:
4683 		if (!capable(CAP_NET_ADMIN))
4684 			return -EPERM;
4685 		dev_load(net, ifr.ifr_name);
4686 		rtnl_lock();
4687 		ret = dev_ifsioc(net, &ifr, cmd);
4688 		rtnl_unlock();
4689 		if (!ret) {
4690 			if (colon)
4691 				*colon = ':';
4692 			if (copy_to_user(arg, &ifr,
4693 					 sizeof(struct ifreq)))
4694 				ret = -EFAULT;
4695 		}
4696 		return ret;
4697 
4698 	/*
4699 	 *	These ioctl calls:
4700 	 *	- require superuser power.
4701 	 *	- require strict serialization.
4702 	 *	- do not return a value
4703 	 */
4704 	case SIOCSIFFLAGS:
4705 	case SIOCSIFMETRIC:
4706 	case SIOCSIFMTU:
4707 	case SIOCSIFMAP:
4708 	case SIOCSIFHWADDR:
4709 	case SIOCSIFSLAVE:
4710 	case SIOCADDMULTI:
4711 	case SIOCDELMULTI:
4712 	case SIOCSIFHWBROADCAST:
4713 	case SIOCSIFTXQLEN:
4714 	case SIOCSMIIREG:
4715 	case SIOCBONDENSLAVE:
4716 	case SIOCBONDRELEASE:
4717 	case SIOCBONDSETHWADDR:
4718 	case SIOCBONDCHANGEACTIVE:
4719 	case SIOCBRADDIF:
4720 	case SIOCBRDELIF:
4721 	case SIOCSHWTSTAMP:
4722 		if (!capable(CAP_NET_ADMIN))
4723 			return -EPERM;
4724 		/* fall through */
4725 	case SIOCBONDSLAVEINFOQUERY:
4726 	case SIOCBONDINFOQUERY:
4727 		dev_load(net, ifr.ifr_name);
4728 		rtnl_lock();
4729 		ret = dev_ifsioc(net, &ifr, cmd);
4730 		rtnl_unlock();
4731 		return ret;
4732 
4733 	case SIOCGIFMEM:
4734 		/* Get the per device memory space. We can add this but
4735 		 * currently do not support it */
4736 	case SIOCSIFMEM:
4737 		/* Set the per device memory buffer space.
4738 		 * Not applicable in our case */
4739 	case SIOCSIFLINK:
4740 		return -EINVAL;
4741 
4742 	/*
4743 	 *	Unknown or private ioctl.
4744 	 */
4745 	default:
4746 		if (cmd == SIOCWANDEV ||
4747 		    (cmd >= SIOCDEVPRIVATE &&
4748 		     cmd <= SIOCDEVPRIVATE + 15)) {
4749 			dev_load(net, ifr.ifr_name);
4750 			rtnl_lock();
4751 			ret = dev_ifsioc(net, &ifr, cmd);
4752 			rtnl_unlock();
4753 			if (!ret && copy_to_user(arg, &ifr,
4754 						 sizeof(struct ifreq)))
4755 				ret = -EFAULT;
4756 			return ret;
4757 		}
4758 		/* Take care of Wireless Extensions */
4759 		if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
4760 			return wext_handle_ioctl(net, &ifr, cmd, arg);
4761 		return -EINVAL;
4762 	}
4763 }
4764 
4765 
4766 /**
4767  *	dev_new_index	-	allocate an ifindex
4768  *	@net: the applicable net namespace
4769  *
4770  *	Returns a suitable unique value for a new device interface
4771  *	number.  The caller must hold the rtnl semaphore or the
4772  *	dev_base_lock to be sure it remains unique.
4773  */
4774 static int dev_new_index(struct net *net)
4775 {
4776 	static int ifindex;
4777 	for (;;) {
4778 		if (++ifindex <= 0)
4779 			ifindex = 1;
4780 		if (!__dev_get_by_index(net, ifindex))
4781 			return ifindex;
4782 	}
4783 }
4784 
4785 /* Delayed registration/unregisteration */
4786 static LIST_HEAD(net_todo_list);
4787 
4788 static void net_set_todo(struct net_device *dev)
4789 {
4790 	list_add_tail(&dev->todo_list, &net_todo_list);
4791 }
4792 
4793 static void rollback_registered_many(struct list_head *head)
4794 {
4795 	struct net_device *dev, *tmp;
4796 
4797 	BUG_ON(dev_boot_phase);
4798 	ASSERT_RTNL();
4799 
4800 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
4801 		/* Some devices call without registering
4802 		 * for initialization unwind. Remove those
4803 		 * devices and proceed with the remaining.
4804 		 */
4805 		if (dev->reg_state == NETREG_UNINITIALIZED) {
4806 			pr_debug("unregister_netdevice: device %s/%p never "
4807 				 "was registered\n", dev->name, dev);
4808 
4809 			WARN_ON(1);
4810 			list_del(&dev->unreg_list);
4811 			continue;
4812 		}
4813 
4814 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
4815 
4816 		/* If device is running, close it first. */
4817 		dev_close(dev);
4818 
4819 		/* And unlink it from device chain. */
4820 		unlist_netdevice(dev);
4821 
4822 		dev->reg_state = NETREG_UNREGISTERING;
4823 	}
4824 
4825 	synchronize_net();
4826 
4827 	list_for_each_entry(dev, head, unreg_list) {
4828 		/* Shutdown queueing discipline. */
4829 		dev_shutdown(dev);
4830 
4831 
4832 		/* Notify protocols, that we are about to destroy
4833 		   this device. They should clean all the things.
4834 		*/
4835 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
4836 
4837 		/*
4838 		 *	Flush the unicast and multicast chains
4839 		 */
4840 		dev_unicast_flush(dev);
4841 		dev_addr_discard(dev);
4842 
4843 		if (dev->netdev_ops->ndo_uninit)
4844 			dev->netdev_ops->ndo_uninit(dev);
4845 
4846 		/* Notifier chain MUST detach us from master device. */
4847 		WARN_ON(dev->master);
4848 
4849 		/* Remove entries from kobject tree */
4850 		netdev_unregister_kobject(dev);
4851 	}
4852 
4853 	/* Process any work delayed until the end of the batch */
4854 	dev = list_entry(head->next, struct net_device, unreg_list);
4855 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
4856 
4857 	synchronize_net();
4858 
4859 	list_for_each_entry(dev, head, unreg_list)
4860 		dev_put(dev);
4861 }
4862 
4863 static void rollback_registered(struct net_device *dev)
4864 {
4865 	LIST_HEAD(single);
4866 
4867 	list_add(&dev->unreg_list, &single);
4868 	rollback_registered_many(&single);
4869 }
4870 
4871 static void __netdev_init_queue_locks_one(struct net_device *dev,
4872 					  struct netdev_queue *dev_queue,
4873 					  void *_unused)
4874 {
4875 	spin_lock_init(&dev_queue->_xmit_lock);
4876 	netdev_set_xmit_lockdep_class(&dev_queue->_xmit_lock, dev->type);
4877 	dev_queue->xmit_lock_owner = -1;
4878 }
4879 
4880 static void netdev_init_queue_locks(struct net_device *dev)
4881 {
4882 	netdev_for_each_tx_queue(dev, __netdev_init_queue_locks_one, NULL);
4883 	__netdev_init_queue_locks_one(dev, &dev->rx_queue, NULL);
4884 }
4885 
4886 unsigned long netdev_fix_features(unsigned long features, const char *name)
4887 {
4888 	/* Fix illegal SG+CSUM combinations. */
4889 	if ((features & NETIF_F_SG) &&
4890 	    !(features & NETIF_F_ALL_CSUM)) {
4891 		if (name)
4892 			printk(KERN_NOTICE "%s: Dropping NETIF_F_SG since no "
4893 			       "checksum feature.\n", name);
4894 		features &= ~NETIF_F_SG;
4895 	}
4896 
4897 	/* TSO requires that SG is present as well. */
4898 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_SG)) {
4899 		if (name)
4900 			printk(KERN_NOTICE "%s: Dropping NETIF_F_TSO since no "
4901 			       "SG feature.\n", name);
4902 		features &= ~NETIF_F_TSO;
4903 	}
4904 
4905 	if (features & NETIF_F_UFO) {
4906 		if (!(features & NETIF_F_GEN_CSUM)) {
4907 			if (name)
4908 				printk(KERN_ERR "%s: Dropping NETIF_F_UFO "
4909 				       "since no NETIF_F_HW_CSUM feature.\n",
4910 				       name);
4911 			features &= ~NETIF_F_UFO;
4912 		}
4913 
4914 		if (!(features & NETIF_F_SG)) {
4915 			if (name)
4916 				printk(KERN_ERR "%s: Dropping NETIF_F_UFO "
4917 				       "since no NETIF_F_SG feature.\n", name);
4918 			features &= ~NETIF_F_UFO;
4919 		}
4920 	}
4921 
4922 	return features;
4923 }
4924 EXPORT_SYMBOL(netdev_fix_features);
4925 
4926 /**
4927  *	netif_stacked_transfer_operstate -	transfer operstate
4928  *	@rootdev: the root or lower level device to transfer state from
4929  *	@dev: the device to transfer operstate to
4930  *
4931  *	Transfer operational state from root to device. This is normally
4932  *	called when a stacking relationship exists between the root
4933  *	device and the device(a leaf device).
4934  */
4935 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
4936 					struct net_device *dev)
4937 {
4938 	if (rootdev->operstate == IF_OPER_DORMANT)
4939 		netif_dormant_on(dev);
4940 	else
4941 		netif_dormant_off(dev);
4942 
4943 	if (netif_carrier_ok(rootdev)) {
4944 		if (!netif_carrier_ok(dev))
4945 			netif_carrier_on(dev);
4946 	} else {
4947 		if (netif_carrier_ok(dev))
4948 			netif_carrier_off(dev);
4949 	}
4950 }
4951 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
4952 
4953 /**
4954  *	register_netdevice	- register a network device
4955  *	@dev: device to register
4956  *
4957  *	Take a completed network device structure and add it to the kernel
4958  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
4959  *	chain. 0 is returned on success. A negative errno code is returned
4960  *	on a failure to set up the device, or if the name is a duplicate.
4961  *
4962  *	Callers must hold the rtnl semaphore. You may want
4963  *	register_netdev() instead of this.
4964  *
4965  *	BUGS:
4966  *	The locking appears insufficient to guarantee two parallel registers
4967  *	will not get the same name.
4968  */
4969 
4970 int register_netdevice(struct net_device *dev)
4971 {
4972 	int ret;
4973 	struct net *net = dev_net(dev);
4974 
4975 	BUG_ON(dev_boot_phase);
4976 	ASSERT_RTNL();
4977 
4978 	might_sleep();
4979 
4980 	/* When net_device's are persistent, this will be fatal. */
4981 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
4982 	BUG_ON(!net);
4983 
4984 	spin_lock_init(&dev->addr_list_lock);
4985 	netdev_set_addr_lockdep_class(dev);
4986 	netdev_init_queue_locks(dev);
4987 
4988 	dev->iflink = -1;
4989 
4990 	/* Init, if this function is available */
4991 	if (dev->netdev_ops->ndo_init) {
4992 		ret = dev->netdev_ops->ndo_init(dev);
4993 		if (ret) {
4994 			if (ret > 0)
4995 				ret = -EIO;
4996 			goto out;
4997 		}
4998 	}
4999 
5000 	ret = dev_get_valid_name(net, dev->name, dev->name, 0);
5001 	if (ret)
5002 		goto err_uninit;
5003 
5004 	dev->ifindex = dev_new_index(net);
5005 	if (dev->iflink == -1)
5006 		dev->iflink = dev->ifindex;
5007 
5008 	/* Fix illegal checksum combinations */
5009 	if ((dev->features & NETIF_F_HW_CSUM) &&
5010 	    (dev->features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5011 		printk(KERN_NOTICE "%s: mixed HW and IP checksum settings.\n",
5012 		       dev->name);
5013 		dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
5014 	}
5015 
5016 	if ((dev->features & NETIF_F_NO_CSUM) &&
5017 	    (dev->features & (NETIF_F_HW_CSUM|NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5018 		printk(KERN_NOTICE "%s: mixed no checksumming and other settings.\n",
5019 		       dev->name);
5020 		dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM|NETIF_F_HW_CSUM);
5021 	}
5022 
5023 	dev->features = netdev_fix_features(dev->features, dev->name);
5024 
5025 	/* Enable software GSO if SG is supported. */
5026 	if (dev->features & NETIF_F_SG)
5027 		dev->features |= NETIF_F_GSO;
5028 
5029 	netdev_initialize_kobject(dev);
5030 
5031 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5032 	ret = notifier_to_errno(ret);
5033 	if (ret)
5034 		goto err_uninit;
5035 
5036 	ret = netdev_register_kobject(dev);
5037 	if (ret)
5038 		goto err_uninit;
5039 	dev->reg_state = NETREG_REGISTERED;
5040 
5041 	/*
5042 	 *	Default initial state at registry is that the
5043 	 *	device is present.
5044 	 */
5045 
5046 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5047 
5048 	dev_init_scheduler(dev);
5049 	dev_hold(dev);
5050 	list_netdevice(dev);
5051 
5052 	/* Notify protocols, that a new device appeared. */
5053 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5054 	ret = notifier_to_errno(ret);
5055 	if (ret) {
5056 		rollback_registered(dev);
5057 		dev->reg_state = NETREG_UNREGISTERED;
5058 	}
5059 	/*
5060 	 *	Prevent userspace races by waiting until the network
5061 	 *	device is fully setup before sending notifications.
5062 	 */
5063 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5064 
5065 out:
5066 	return ret;
5067 
5068 err_uninit:
5069 	if (dev->netdev_ops->ndo_uninit)
5070 		dev->netdev_ops->ndo_uninit(dev);
5071 	goto out;
5072 }
5073 EXPORT_SYMBOL(register_netdevice);
5074 
5075 /**
5076  *	init_dummy_netdev	- init a dummy network device for NAPI
5077  *	@dev: device to init
5078  *
5079  *	This takes a network device structure and initialize the minimum
5080  *	amount of fields so it can be used to schedule NAPI polls without
5081  *	registering a full blown interface. This is to be used by drivers
5082  *	that need to tie several hardware interfaces to a single NAPI
5083  *	poll scheduler due to HW limitations.
5084  */
5085 int init_dummy_netdev(struct net_device *dev)
5086 {
5087 	/* Clear everything. Note we don't initialize spinlocks
5088 	 * are they aren't supposed to be taken by any of the
5089 	 * NAPI code and this dummy netdev is supposed to be
5090 	 * only ever used for NAPI polls
5091 	 */
5092 	memset(dev, 0, sizeof(struct net_device));
5093 
5094 	/* make sure we BUG if trying to hit standard
5095 	 * register/unregister code path
5096 	 */
5097 	dev->reg_state = NETREG_DUMMY;
5098 
5099 	/* initialize the ref count */
5100 	atomic_set(&dev->refcnt, 1);
5101 
5102 	/* NAPI wants this */
5103 	INIT_LIST_HEAD(&dev->napi_list);
5104 
5105 	/* a dummy interface is started by default */
5106 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5107 	set_bit(__LINK_STATE_START, &dev->state);
5108 
5109 	return 0;
5110 }
5111 EXPORT_SYMBOL_GPL(init_dummy_netdev);
5112 
5113 
5114 /**
5115  *	register_netdev	- register a network device
5116  *	@dev: device to register
5117  *
5118  *	Take a completed network device structure and add it to the kernel
5119  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5120  *	chain. 0 is returned on success. A negative errno code is returned
5121  *	on a failure to set up the device, or if the name is a duplicate.
5122  *
5123  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
5124  *	and expands the device name if you passed a format string to
5125  *	alloc_netdev.
5126  */
5127 int register_netdev(struct net_device *dev)
5128 {
5129 	int err;
5130 
5131 	rtnl_lock();
5132 
5133 	/*
5134 	 * If the name is a format string the caller wants us to do a
5135 	 * name allocation.
5136 	 */
5137 	if (strchr(dev->name, '%')) {
5138 		err = dev_alloc_name(dev, dev->name);
5139 		if (err < 0)
5140 			goto out;
5141 	}
5142 
5143 	err = register_netdevice(dev);
5144 out:
5145 	rtnl_unlock();
5146 	return err;
5147 }
5148 EXPORT_SYMBOL(register_netdev);
5149 
5150 /*
5151  * netdev_wait_allrefs - wait until all references are gone.
5152  *
5153  * This is called when unregistering network devices.
5154  *
5155  * Any protocol or device that holds a reference should register
5156  * for netdevice notification, and cleanup and put back the
5157  * reference if they receive an UNREGISTER event.
5158  * We can get stuck here if buggy protocols don't correctly
5159  * call dev_put.
5160  */
5161 static void netdev_wait_allrefs(struct net_device *dev)
5162 {
5163 	unsigned long rebroadcast_time, warning_time;
5164 
5165 	linkwatch_forget_dev(dev);
5166 
5167 	rebroadcast_time = warning_time = jiffies;
5168 	while (atomic_read(&dev->refcnt) != 0) {
5169 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5170 			rtnl_lock();
5171 
5172 			/* Rebroadcast unregister notification */
5173 			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5174 			/* don't resend NETDEV_UNREGISTER_BATCH, _BATCH users
5175 			 * should have already handle it the first time */
5176 
5177 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
5178 				     &dev->state)) {
5179 				/* We must not have linkwatch events
5180 				 * pending on unregister. If this
5181 				 * happens, we simply run the queue
5182 				 * unscheduled, resulting in a noop
5183 				 * for this device.
5184 				 */
5185 				linkwatch_run_queue();
5186 			}
5187 
5188 			__rtnl_unlock();
5189 
5190 			rebroadcast_time = jiffies;
5191 		}
5192 
5193 		msleep(250);
5194 
5195 		if (time_after(jiffies, warning_time + 10 * HZ)) {
5196 			printk(KERN_EMERG "unregister_netdevice: "
5197 			       "waiting for %s to become free. Usage "
5198 			       "count = %d\n",
5199 			       dev->name, atomic_read(&dev->refcnt));
5200 			warning_time = jiffies;
5201 		}
5202 	}
5203 }
5204 
5205 /* The sequence is:
5206  *
5207  *	rtnl_lock();
5208  *	...
5209  *	register_netdevice(x1);
5210  *	register_netdevice(x2);
5211  *	...
5212  *	unregister_netdevice(y1);
5213  *	unregister_netdevice(y2);
5214  *      ...
5215  *	rtnl_unlock();
5216  *	free_netdev(y1);
5217  *	free_netdev(y2);
5218  *
5219  * We are invoked by rtnl_unlock().
5220  * This allows us to deal with problems:
5221  * 1) We can delete sysfs objects which invoke hotplug
5222  *    without deadlocking with linkwatch via keventd.
5223  * 2) Since we run with the RTNL semaphore not held, we can sleep
5224  *    safely in order to wait for the netdev refcnt to drop to zero.
5225  *
5226  * We must not return until all unregister events added during
5227  * the interval the lock was held have been completed.
5228  */
5229 void netdev_run_todo(void)
5230 {
5231 	struct list_head list;
5232 
5233 	/* Snapshot list, allow later requests */
5234 	list_replace_init(&net_todo_list, &list);
5235 
5236 	__rtnl_unlock();
5237 
5238 	while (!list_empty(&list)) {
5239 		struct net_device *dev
5240 			= list_entry(list.next, struct net_device, todo_list);
5241 		list_del(&dev->todo_list);
5242 
5243 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5244 			printk(KERN_ERR "network todo '%s' but state %d\n",
5245 			       dev->name, dev->reg_state);
5246 			dump_stack();
5247 			continue;
5248 		}
5249 
5250 		dev->reg_state = NETREG_UNREGISTERED;
5251 
5252 		on_each_cpu(flush_backlog, dev, 1);
5253 
5254 		netdev_wait_allrefs(dev);
5255 
5256 		/* paranoia */
5257 		BUG_ON(atomic_read(&dev->refcnt));
5258 		WARN_ON(dev->ip_ptr);
5259 		WARN_ON(dev->ip6_ptr);
5260 		WARN_ON(dev->dn_ptr);
5261 
5262 		if (dev->destructor)
5263 			dev->destructor(dev);
5264 
5265 		/* Free network device */
5266 		kobject_put(&dev->dev.kobj);
5267 	}
5268 }
5269 
5270 /**
5271  *	dev_txq_stats_fold - fold tx_queues stats
5272  *	@dev: device to get statistics from
5273  *	@stats: struct net_device_stats to hold results
5274  */
5275 void dev_txq_stats_fold(const struct net_device *dev,
5276 			struct net_device_stats *stats)
5277 {
5278 	unsigned long tx_bytes = 0, tx_packets = 0, tx_dropped = 0;
5279 	unsigned int i;
5280 	struct netdev_queue *txq;
5281 
5282 	for (i = 0; i < dev->num_tx_queues; i++) {
5283 		txq = netdev_get_tx_queue(dev, i);
5284 		tx_bytes   += txq->tx_bytes;
5285 		tx_packets += txq->tx_packets;
5286 		tx_dropped += txq->tx_dropped;
5287 	}
5288 	if (tx_bytes || tx_packets || tx_dropped) {
5289 		stats->tx_bytes   = tx_bytes;
5290 		stats->tx_packets = tx_packets;
5291 		stats->tx_dropped = tx_dropped;
5292 	}
5293 }
5294 EXPORT_SYMBOL(dev_txq_stats_fold);
5295 
5296 /**
5297  *	dev_get_stats	- get network device statistics
5298  *	@dev: device to get statistics from
5299  *
5300  *	Get network statistics from device. The device driver may provide
5301  *	its own method by setting dev->netdev_ops->get_stats; otherwise
5302  *	the internal statistics structure is used.
5303  */
5304 const struct net_device_stats *dev_get_stats(struct net_device *dev)
5305 {
5306 	const struct net_device_ops *ops = dev->netdev_ops;
5307 
5308 	if (ops->ndo_get_stats)
5309 		return ops->ndo_get_stats(dev);
5310 
5311 	dev_txq_stats_fold(dev, &dev->stats);
5312 	return &dev->stats;
5313 }
5314 EXPORT_SYMBOL(dev_get_stats);
5315 
5316 static void netdev_init_one_queue(struct net_device *dev,
5317 				  struct netdev_queue *queue,
5318 				  void *_unused)
5319 {
5320 	queue->dev = dev;
5321 }
5322 
5323 static void netdev_init_queues(struct net_device *dev)
5324 {
5325 	netdev_init_one_queue(dev, &dev->rx_queue, NULL);
5326 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5327 	spin_lock_init(&dev->tx_global_lock);
5328 }
5329 
5330 /**
5331  *	alloc_netdev_mq - allocate network device
5332  *	@sizeof_priv:	size of private data to allocate space for
5333  *	@name:		device name format string
5334  *	@setup:		callback to initialize device
5335  *	@queue_count:	the number of subqueues to allocate
5336  *
5337  *	Allocates a struct net_device with private data area for driver use
5338  *	and performs basic initialization.  Also allocates subquue structs
5339  *	for each queue on the device at the end of the netdevice.
5340  */
5341 struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
5342 		void (*setup)(struct net_device *), unsigned int queue_count)
5343 {
5344 	struct netdev_queue *tx;
5345 	struct net_device *dev;
5346 	size_t alloc_size;
5347 	struct net_device *p;
5348 
5349 	BUG_ON(strlen(name) >= sizeof(dev->name));
5350 
5351 	alloc_size = sizeof(struct net_device);
5352 	if (sizeof_priv) {
5353 		/* ensure 32-byte alignment of private area */
5354 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5355 		alloc_size += sizeof_priv;
5356 	}
5357 	/* ensure 32-byte alignment of whole construct */
5358 	alloc_size += NETDEV_ALIGN - 1;
5359 
5360 	p = kzalloc(alloc_size, GFP_KERNEL);
5361 	if (!p) {
5362 		printk(KERN_ERR "alloc_netdev: Unable to allocate device.\n");
5363 		return NULL;
5364 	}
5365 
5366 	tx = kcalloc(queue_count, sizeof(struct netdev_queue), GFP_KERNEL);
5367 	if (!tx) {
5368 		printk(KERN_ERR "alloc_netdev: Unable to allocate "
5369 		       "tx qdiscs.\n");
5370 		goto free_p;
5371 	}
5372 
5373 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
5374 	dev->padded = (char *)dev - (char *)p;
5375 
5376 	if (dev_addr_init(dev))
5377 		goto free_tx;
5378 
5379 	dev_unicast_init(dev);
5380 
5381 	dev_net_set(dev, &init_net);
5382 
5383 	dev->_tx = tx;
5384 	dev->num_tx_queues = queue_count;
5385 	dev->real_num_tx_queues = queue_count;
5386 
5387 	dev->gso_max_size = GSO_MAX_SIZE;
5388 
5389 	netdev_init_queues(dev);
5390 
5391 	INIT_LIST_HEAD(&dev->napi_list);
5392 	INIT_LIST_HEAD(&dev->unreg_list);
5393 	INIT_LIST_HEAD(&dev->link_watch_list);
5394 	dev->priv_flags = IFF_XMIT_DST_RELEASE;
5395 	setup(dev);
5396 	strcpy(dev->name, name);
5397 	return dev;
5398 
5399 free_tx:
5400 	kfree(tx);
5401 
5402 free_p:
5403 	kfree(p);
5404 	return NULL;
5405 }
5406 EXPORT_SYMBOL(alloc_netdev_mq);
5407 
5408 /**
5409  *	free_netdev - free network device
5410  *	@dev: device
5411  *
5412  *	This function does the last stage of destroying an allocated device
5413  * 	interface. The reference to the device object is released.
5414  *	If this is the last reference then it will be freed.
5415  */
5416 void free_netdev(struct net_device *dev)
5417 {
5418 	struct napi_struct *p, *n;
5419 
5420 	release_net(dev_net(dev));
5421 
5422 	kfree(dev->_tx);
5423 
5424 	/* Flush device addresses */
5425 	dev_addr_flush(dev);
5426 
5427 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
5428 		netif_napi_del(p);
5429 
5430 	/*  Compatibility with error handling in drivers */
5431 	if (dev->reg_state == NETREG_UNINITIALIZED) {
5432 		kfree((char *)dev - dev->padded);
5433 		return;
5434 	}
5435 
5436 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
5437 	dev->reg_state = NETREG_RELEASED;
5438 
5439 	/* will free via device release */
5440 	put_device(&dev->dev);
5441 }
5442 EXPORT_SYMBOL(free_netdev);
5443 
5444 /**
5445  *	synchronize_net -  Synchronize with packet receive processing
5446  *
5447  *	Wait for packets currently being received to be done.
5448  *	Does not block later packets from starting.
5449  */
5450 void synchronize_net(void)
5451 {
5452 	might_sleep();
5453 	synchronize_rcu();
5454 }
5455 EXPORT_SYMBOL(synchronize_net);
5456 
5457 /**
5458  *	unregister_netdevice_queue - remove device from the kernel
5459  *	@dev: device
5460  *	@head: list
5461  *
5462  *	This function shuts down a device interface and removes it
5463  *	from the kernel tables.
5464  *	If head not NULL, device is queued to be unregistered later.
5465  *
5466  *	Callers must hold the rtnl semaphore.  You may want
5467  *	unregister_netdev() instead of this.
5468  */
5469 
5470 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
5471 {
5472 	ASSERT_RTNL();
5473 
5474 	if (head) {
5475 		list_move_tail(&dev->unreg_list, head);
5476 	} else {
5477 		rollback_registered(dev);
5478 		/* Finish processing unregister after unlock */
5479 		net_set_todo(dev);
5480 	}
5481 }
5482 EXPORT_SYMBOL(unregister_netdevice_queue);
5483 
5484 /**
5485  *	unregister_netdevice_many - unregister many devices
5486  *	@head: list of devices
5487  */
5488 void unregister_netdevice_many(struct list_head *head)
5489 {
5490 	struct net_device *dev;
5491 
5492 	if (!list_empty(head)) {
5493 		rollback_registered_many(head);
5494 		list_for_each_entry(dev, head, unreg_list)
5495 			net_set_todo(dev);
5496 	}
5497 }
5498 EXPORT_SYMBOL(unregister_netdevice_many);
5499 
5500 /**
5501  *	unregister_netdev - remove device from the kernel
5502  *	@dev: device
5503  *
5504  *	This function shuts down a device interface and removes it
5505  *	from the kernel tables.
5506  *
5507  *	This is just a wrapper for unregister_netdevice that takes
5508  *	the rtnl semaphore.  In general you want to use this and not
5509  *	unregister_netdevice.
5510  */
5511 void unregister_netdev(struct net_device *dev)
5512 {
5513 	rtnl_lock();
5514 	unregister_netdevice(dev);
5515 	rtnl_unlock();
5516 }
5517 EXPORT_SYMBOL(unregister_netdev);
5518 
5519 /**
5520  *	dev_change_net_namespace - move device to different nethost namespace
5521  *	@dev: device
5522  *	@net: network namespace
5523  *	@pat: If not NULL name pattern to try if the current device name
5524  *	      is already taken in the destination network namespace.
5525  *
5526  *	This function shuts down a device interface and moves it
5527  *	to a new network namespace. On success 0 is returned, on
5528  *	a failure a netagive errno code is returned.
5529  *
5530  *	Callers must hold the rtnl semaphore.
5531  */
5532 
5533 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
5534 {
5535 	int err;
5536 
5537 	ASSERT_RTNL();
5538 
5539 	/* Don't allow namespace local devices to be moved. */
5540 	err = -EINVAL;
5541 	if (dev->features & NETIF_F_NETNS_LOCAL)
5542 		goto out;
5543 
5544 #ifdef CONFIG_SYSFS
5545 	/* Don't allow real devices to be moved when sysfs
5546 	 * is enabled.
5547 	 */
5548 	err = -EINVAL;
5549 	if (dev->dev.parent)
5550 		goto out;
5551 #endif
5552 
5553 	/* Ensure the device has been registrered */
5554 	err = -EINVAL;
5555 	if (dev->reg_state != NETREG_REGISTERED)
5556 		goto out;
5557 
5558 	/* Get out if there is nothing todo */
5559 	err = 0;
5560 	if (net_eq(dev_net(dev), net))
5561 		goto out;
5562 
5563 	/* Pick the destination device name, and ensure
5564 	 * we can use it in the destination network namespace.
5565 	 */
5566 	err = -EEXIST;
5567 	if (__dev_get_by_name(net, dev->name)) {
5568 		/* We get here if we can't use the current device name */
5569 		if (!pat)
5570 			goto out;
5571 		if (dev_get_valid_name(net, pat, dev->name, 1))
5572 			goto out;
5573 	}
5574 
5575 	/*
5576 	 * And now a mini version of register_netdevice unregister_netdevice.
5577 	 */
5578 
5579 	/* If device is running close it first. */
5580 	dev_close(dev);
5581 
5582 	/* And unlink it from device chain */
5583 	err = -ENODEV;
5584 	unlist_netdevice(dev);
5585 
5586 	synchronize_net();
5587 
5588 	/* Shutdown queueing discipline. */
5589 	dev_shutdown(dev);
5590 
5591 	/* Notify protocols, that we are about to destroy
5592 	   this device. They should clean all the things.
5593 	*/
5594 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5595 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
5596 
5597 	/*
5598 	 *	Flush the unicast and multicast chains
5599 	 */
5600 	dev_unicast_flush(dev);
5601 	dev_addr_discard(dev);
5602 
5603 	netdev_unregister_kobject(dev);
5604 
5605 	/* Actually switch the network namespace */
5606 	dev_net_set(dev, net);
5607 
5608 	/* If there is an ifindex conflict assign a new one */
5609 	if (__dev_get_by_index(net, dev->ifindex)) {
5610 		int iflink = (dev->iflink == dev->ifindex);
5611 		dev->ifindex = dev_new_index(net);
5612 		if (iflink)
5613 			dev->iflink = dev->ifindex;
5614 	}
5615 
5616 	/* Fixup kobjects */
5617 	err = netdev_register_kobject(dev);
5618 	WARN_ON(err);
5619 
5620 	/* Add the device back in the hashes */
5621 	list_netdevice(dev);
5622 
5623 	/* Notify protocols, that a new device appeared. */
5624 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
5625 
5626 	/*
5627 	 *	Prevent userspace races by waiting until the network
5628 	 *	device is fully setup before sending notifications.
5629 	 */
5630 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5631 
5632 	synchronize_net();
5633 	err = 0;
5634 out:
5635 	return err;
5636 }
5637 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
5638 
5639 static int dev_cpu_callback(struct notifier_block *nfb,
5640 			    unsigned long action,
5641 			    void *ocpu)
5642 {
5643 	struct sk_buff **list_skb;
5644 	struct Qdisc **list_net;
5645 	struct sk_buff *skb;
5646 	unsigned int cpu, oldcpu = (unsigned long)ocpu;
5647 	struct softnet_data *sd, *oldsd;
5648 
5649 	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
5650 		return NOTIFY_OK;
5651 
5652 	local_irq_disable();
5653 	cpu = smp_processor_id();
5654 	sd = &per_cpu(softnet_data, cpu);
5655 	oldsd = &per_cpu(softnet_data, oldcpu);
5656 
5657 	/* Find end of our completion_queue. */
5658 	list_skb = &sd->completion_queue;
5659 	while (*list_skb)
5660 		list_skb = &(*list_skb)->next;
5661 	/* Append completion queue from offline CPU. */
5662 	*list_skb = oldsd->completion_queue;
5663 	oldsd->completion_queue = NULL;
5664 
5665 	/* Find end of our output_queue. */
5666 	list_net = &sd->output_queue;
5667 	while (*list_net)
5668 		list_net = &(*list_net)->next_sched;
5669 	/* Append output queue from offline CPU. */
5670 	*list_net = oldsd->output_queue;
5671 	oldsd->output_queue = NULL;
5672 
5673 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
5674 	local_irq_enable();
5675 
5676 	/* Process offline CPU's input_pkt_queue */
5677 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue)))
5678 		netif_rx(skb);
5679 
5680 	return NOTIFY_OK;
5681 }
5682 
5683 
5684 /**
5685  *	netdev_increment_features - increment feature set by one
5686  *	@all: current feature set
5687  *	@one: new feature set
5688  *	@mask: mask feature set
5689  *
5690  *	Computes a new feature set after adding a device with feature set
5691  *	@one to the master device with current feature set @all.  Will not
5692  *	enable anything that is off in @mask. Returns the new feature set.
5693  */
5694 unsigned long netdev_increment_features(unsigned long all, unsigned long one,
5695 					unsigned long mask)
5696 {
5697 	/* If device needs checksumming, downgrade to it. */
5698 	if (all & NETIF_F_NO_CSUM && !(one & NETIF_F_NO_CSUM))
5699 		all ^= NETIF_F_NO_CSUM | (one & NETIF_F_ALL_CSUM);
5700 	else if (mask & NETIF_F_ALL_CSUM) {
5701 		/* If one device supports v4/v6 checksumming, set for all. */
5702 		if (one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM) &&
5703 		    !(all & NETIF_F_GEN_CSUM)) {
5704 			all &= ~NETIF_F_ALL_CSUM;
5705 			all |= one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
5706 		}
5707 
5708 		/* If one device supports hw checksumming, set for all. */
5709 		if (one & NETIF_F_GEN_CSUM && !(all & NETIF_F_GEN_CSUM)) {
5710 			all &= ~NETIF_F_ALL_CSUM;
5711 			all |= NETIF_F_HW_CSUM;
5712 		}
5713 	}
5714 
5715 	one |= NETIF_F_ALL_CSUM;
5716 
5717 	one |= all & NETIF_F_ONE_FOR_ALL;
5718 	all &= one | NETIF_F_LLTX | NETIF_F_GSO | NETIF_F_UFO;
5719 	all |= one & mask & NETIF_F_ONE_FOR_ALL;
5720 
5721 	return all;
5722 }
5723 EXPORT_SYMBOL(netdev_increment_features);
5724 
5725 static struct hlist_head *netdev_create_hash(void)
5726 {
5727 	int i;
5728 	struct hlist_head *hash;
5729 
5730 	hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
5731 	if (hash != NULL)
5732 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
5733 			INIT_HLIST_HEAD(&hash[i]);
5734 
5735 	return hash;
5736 }
5737 
5738 /* Initialize per network namespace state */
5739 static int __net_init netdev_init(struct net *net)
5740 {
5741 	INIT_LIST_HEAD(&net->dev_base_head);
5742 
5743 	net->dev_name_head = netdev_create_hash();
5744 	if (net->dev_name_head == NULL)
5745 		goto err_name;
5746 
5747 	net->dev_index_head = netdev_create_hash();
5748 	if (net->dev_index_head == NULL)
5749 		goto err_idx;
5750 
5751 	return 0;
5752 
5753 err_idx:
5754 	kfree(net->dev_name_head);
5755 err_name:
5756 	return -ENOMEM;
5757 }
5758 
5759 /**
5760  *	netdev_drivername - network driver for the device
5761  *	@dev: network device
5762  *	@buffer: buffer for resulting name
5763  *	@len: size of buffer
5764  *
5765  *	Determine network driver for device.
5766  */
5767 char *netdev_drivername(const struct net_device *dev, char *buffer, int len)
5768 {
5769 	const struct device_driver *driver;
5770 	const struct device *parent;
5771 
5772 	if (len <= 0 || !buffer)
5773 		return buffer;
5774 	buffer[0] = 0;
5775 
5776 	parent = dev->dev.parent;
5777 
5778 	if (!parent)
5779 		return buffer;
5780 
5781 	driver = parent->driver;
5782 	if (driver && driver->name)
5783 		strlcpy(buffer, driver->name, len);
5784 	return buffer;
5785 }
5786 
5787 static void __net_exit netdev_exit(struct net *net)
5788 {
5789 	kfree(net->dev_name_head);
5790 	kfree(net->dev_index_head);
5791 }
5792 
5793 static struct pernet_operations __net_initdata netdev_net_ops = {
5794 	.init = netdev_init,
5795 	.exit = netdev_exit,
5796 };
5797 
5798 static void __net_exit default_device_exit(struct net *net)
5799 {
5800 	struct net_device *dev, *aux;
5801 	/*
5802 	 * Push all migratable network devices back to the
5803 	 * initial network namespace
5804 	 */
5805 	rtnl_lock();
5806 	for_each_netdev_safe(net, dev, aux) {
5807 		int err;
5808 		char fb_name[IFNAMSIZ];
5809 
5810 		/* Ignore unmoveable devices (i.e. loopback) */
5811 		if (dev->features & NETIF_F_NETNS_LOCAL)
5812 			continue;
5813 
5814 		/* Leave virtual devices for the generic cleanup */
5815 		if (dev->rtnl_link_ops)
5816 			continue;
5817 
5818 		/* Push remaing network devices to init_net */
5819 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
5820 		err = dev_change_net_namespace(dev, &init_net, fb_name);
5821 		if (err) {
5822 			printk(KERN_EMERG "%s: failed to move %s to init_net: %d\n",
5823 				__func__, dev->name, err);
5824 			BUG();
5825 		}
5826 	}
5827 	rtnl_unlock();
5828 }
5829 
5830 static void __net_exit default_device_exit_batch(struct list_head *net_list)
5831 {
5832 	/* At exit all network devices most be removed from a network
5833 	 * namespace.  Do this in the reverse order of registeration.
5834 	 * Do this across as many network namespaces as possible to
5835 	 * improve batching efficiency.
5836 	 */
5837 	struct net_device *dev;
5838 	struct net *net;
5839 	LIST_HEAD(dev_kill_list);
5840 
5841 	rtnl_lock();
5842 	list_for_each_entry(net, net_list, exit_list) {
5843 		for_each_netdev_reverse(net, dev) {
5844 			if (dev->rtnl_link_ops)
5845 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
5846 			else
5847 				unregister_netdevice_queue(dev, &dev_kill_list);
5848 		}
5849 	}
5850 	unregister_netdevice_many(&dev_kill_list);
5851 	rtnl_unlock();
5852 }
5853 
5854 static struct pernet_operations __net_initdata default_device_ops = {
5855 	.exit = default_device_exit,
5856 	.exit_batch = default_device_exit_batch,
5857 };
5858 
5859 /*
5860  *	Initialize the DEV module. At boot time this walks the device list and
5861  *	unhooks any devices that fail to initialise (normally hardware not
5862  *	present) and leaves us with a valid list of present and active devices.
5863  *
5864  */
5865 
5866 /*
5867  *       This is called single threaded during boot, so no need
5868  *       to take the rtnl semaphore.
5869  */
5870 static int __init net_dev_init(void)
5871 {
5872 	int i, rc = -ENOMEM;
5873 
5874 	BUG_ON(!dev_boot_phase);
5875 
5876 	if (dev_proc_init())
5877 		goto out;
5878 
5879 	if (netdev_kobject_init())
5880 		goto out;
5881 
5882 	INIT_LIST_HEAD(&ptype_all);
5883 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
5884 		INIT_LIST_HEAD(&ptype_base[i]);
5885 
5886 	if (register_pernet_subsys(&netdev_net_ops))
5887 		goto out;
5888 
5889 	/*
5890 	 *	Initialise the packet receive queues.
5891 	 */
5892 
5893 	for_each_possible_cpu(i) {
5894 		struct softnet_data *queue;
5895 
5896 		queue = &per_cpu(softnet_data, i);
5897 		skb_queue_head_init(&queue->input_pkt_queue);
5898 		queue->completion_queue = NULL;
5899 		INIT_LIST_HEAD(&queue->poll_list);
5900 
5901 		queue->backlog.poll = process_backlog;
5902 		queue->backlog.weight = weight_p;
5903 		queue->backlog.gro_list = NULL;
5904 		queue->backlog.gro_count = 0;
5905 	}
5906 
5907 	dev_boot_phase = 0;
5908 
5909 	/* The loopback device is special if any other network devices
5910 	 * is present in a network namespace the loopback device must
5911 	 * be present. Since we now dynamically allocate and free the
5912 	 * loopback device ensure this invariant is maintained by
5913 	 * keeping the loopback device as the first device on the
5914 	 * list of network devices.  Ensuring the loopback devices
5915 	 * is the first device that appears and the last network device
5916 	 * that disappears.
5917 	 */
5918 	if (register_pernet_device(&loopback_net_ops))
5919 		goto out;
5920 
5921 	if (register_pernet_device(&default_device_ops))
5922 		goto out;
5923 
5924 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
5925 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
5926 
5927 	hotcpu_notifier(dev_cpu_callback, 0);
5928 	dst_init();
5929 	dev_mcast_init();
5930 	rc = 0;
5931 out:
5932 	return rc;
5933 }
5934 
5935 subsys_initcall(net_dev_init);
5936 
5937 static int __init initialize_hashrnd(void)
5938 {
5939 	get_random_bytes(&skb_tx_hashrnd, sizeof(skb_tx_hashrnd));
5940 	return 0;
5941 }
5942 
5943 late_initcall_sync(initialize_hashrnd);
5944 
5945