xref: /openbmc/linux/net/core/dev.c (revision e190bfe56841551b1ad5abb42ebd0c4798cc8c01)
1 /*
2  * 	NET3	Protocol independent device support routines.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *	Derived from the non IP parts of dev.c 1.0.19
10  * 		Authors:	Ross Biro
11  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
13  *
14  *	Additional Authors:
15  *		Florian la Roche <rzsfl@rz.uni-sb.de>
16  *		Alan Cox <gw4pts@gw4pts.ampr.org>
17  *		David Hinds <dahinds@users.sourceforge.net>
18  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
19  *		Adam Sulmicki <adam@cfar.umd.edu>
20  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
21  *
22  *	Changes:
23  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
24  *              			to 2 if register_netdev gets called
25  *              			before net_dev_init & also removed a
26  *              			few lines of code in the process.
27  *		Alan Cox	:	device private ioctl copies fields back.
28  *		Alan Cox	:	Transmit queue code does relevant
29  *					stunts to keep the queue safe.
30  *		Alan Cox	:	Fixed double lock.
31  *		Alan Cox	:	Fixed promisc NULL pointer trap
32  *		????????	:	Support the full private ioctl range
33  *		Alan Cox	:	Moved ioctl permission check into
34  *					drivers
35  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
36  *		Alan Cox	:	100 backlog just doesn't cut it when
37  *					you start doing multicast video 8)
38  *		Alan Cox	:	Rewrote net_bh and list manager.
39  *		Alan Cox	: 	Fix ETH_P_ALL echoback lengths.
40  *		Alan Cox	:	Took out transmit every packet pass
41  *					Saved a few bytes in the ioctl handler
42  *		Alan Cox	:	Network driver sets packet type before
43  *					calling netif_rx. Saves a function
44  *					call a packet.
45  *		Alan Cox	:	Hashed net_bh()
46  *		Richard Kooijman:	Timestamp fixes.
47  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
48  *		Alan Cox	:	Device lock protection.
49  *		Alan Cox	: 	Fixed nasty side effect of device close
50  *					changes.
51  *		Rudi Cilibrasi	:	Pass the right thing to
52  *					set_mac_address()
53  *		Dave Miller	:	32bit quantity for the device lock to
54  *					make it work out on a Sparc.
55  *		Bjorn Ekwall	:	Added KERNELD hack.
56  *		Alan Cox	:	Cleaned up the backlog initialise.
57  *		Craig Metz	:	SIOCGIFCONF fix if space for under
58  *					1 device.
59  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
60  *					is no device open function.
61  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
62  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
63  *		Cyrus Durgin	:	Cleaned for KMOD
64  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
65  *					A network device unload needs to purge
66  *					the backlog queue.
67  *	Paul Rusty Russell	:	SIOCSIFNAME
68  *              Pekka Riikonen  :	Netdev boot-time settings code
69  *              Andrew Morton   :       Make unregister_netdevice wait
70  *              			indefinitely on dev->refcnt
71  * 		J Hadi Salim	:	- Backlog queue sampling
72  *				        - netif_rx() feedback
73  */
74 
75 #include <asm/uaccess.h>
76 #include <asm/system.h>
77 #include <linux/bitops.h>
78 #include <linux/capability.h>
79 #include <linux/cpu.h>
80 #include <linux/types.h>
81 #include <linux/kernel.h>
82 #include <linux/hash.h>
83 #include <linux/slab.h>
84 #include <linux/sched.h>
85 #include <linux/mutex.h>
86 #include <linux/string.h>
87 #include <linux/mm.h>
88 #include <linux/socket.h>
89 #include <linux/sockios.h>
90 #include <linux/errno.h>
91 #include <linux/interrupt.h>
92 #include <linux/if_ether.h>
93 #include <linux/netdevice.h>
94 #include <linux/etherdevice.h>
95 #include <linux/ethtool.h>
96 #include <linux/notifier.h>
97 #include <linux/skbuff.h>
98 #include <net/net_namespace.h>
99 #include <net/sock.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <linux/stat.h>
104 #include <linux/if_bridge.h>
105 #include <linux/if_macvlan.h>
106 #include <net/dst.h>
107 #include <net/pkt_sched.h>
108 #include <net/checksum.h>
109 #include <net/xfrm.h>
110 #include <linux/highmem.h>
111 #include <linux/init.h>
112 #include <linux/kmod.h>
113 #include <linux/module.h>
114 #include <linux/netpoll.h>
115 #include <linux/rcupdate.h>
116 #include <linux/delay.h>
117 #include <net/wext.h>
118 #include <net/iw_handler.h>
119 #include <asm/current.h>
120 #include <linux/audit.h>
121 #include <linux/dmaengine.h>
122 #include <linux/err.h>
123 #include <linux/ctype.h>
124 #include <linux/if_arp.h>
125 #include <linux/if_vlan.h>
126 #include <linux/ip.h>
127 #include <net/ip.h>
128 #include <linux/ipv6.h>
129 #include <linux/in.h>
130 #include <linux/jhash.h>
131 #include <linux/random.h>
132 #include <trace/events/napi.h>
133 #include <linux/pci.h>
134 
135 #include "net-sysfs.h"
136 
137 /* Instead of increasing this, you should create a hash table. */
138 #define MAX_GRO_SKBS 8
139 
140 /* This should be increased if a protocol with a bigger head is added. */
141 #define GRO_MAX_HEAD (MAX_HEADER + 128)
142 
143 /*
144  *	The list of packet types we will receive (as opposed to discard)
145  *	and the routines to invoke.
146  *
147  *	Why 16. Because with 16 the only overlap we get on a hash of the
148  *	low nibble of the protocol value is RARP/SNAP/X.25.
149  *
150  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
151  *             sure which should go first, but I bet it won't make much
152  *             difference if we are running VLANs.  The good news is that
153  *             this protocol won't be in the list unless compiled in, so
154  *             the average user (w/out VLANs) will not be adversely affected.
155  *             --BLG
156  *
157  *		0800	IP
158  *		8100    802.1Q VLAN
159  *		0001	802.3
160  *		0002	AX.25
161  *		0004	802.2
162  *		8035	RARP
163  *		0005	SNAP
164  *		0805	X.25
165  *		0806	ARP
166  *		8137	IPX
167  *		0009	Localtalk
168  *		86DD	IPv6
169  */
170 
171 #define PTYPE_HASH_SIZE	(16)
172 #define PTYPE_HASH_MASK	(PTYPE_HASH_SIZE - 1)
173 
174 static DEFINE_SPINLOCK(ptype_lock);
175 static struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
176 static struct list_head ptype_all __read_mostly;	/* Taps */
177 
178 /*
179  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
180  * semaphore.
181  *
182  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
183  *
184  * Writers must hold the rtnl semaphore while they loop through the
185  * dev_base_head list, and hold dev_base_lock for writing when they do the
186  * actual updates.  This allows pure readers to access the list even
187  * while a writer is preparing to update it.
188  *
189  * To put it another way, dev_base_lock is held for writing only to
190  * protect against pure readers; the rtnl semaphore provides the
191  * protection against other writers.
192  *
193  * See, for example usages, register_netdevice() and
194  * unregister_netdevice(), which must be called with the rtnl
195  * semaphore held.
196  */
197 DEFINE_RWLOCK(dev_base_lock);
198 EXPORT_SYMBOL(dev_base_lock);
199 
200 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
201 {
202 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
203 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
204 }
205 
206 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
207 {
208 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
209 }
210 
211 static inline void rps_lock(struct softnet_data *sd)
212 {
213 #ifdef CONFIG_RPS
214 	spin_lock(&sd->input_pkt_queue.lock);
215 #endif
216 }
217 
218 static inline void rps_unlock(struct softnet_data *sd)
219 {
220 #ifdef CONFIG_RPS
221 	spin_unlock(&sd->input_pkt_queue.lock);
222 #endif
223 }
224 
225 /* Device list insertion */
226 static int list_netdevice(struct net_device *dev)
227 {
228 	struct net *net = dev_net(dev);
229 
230 	ASSERT_RTNL();
231 
232 	write_lock_bh(&dev_base_lock);
233 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
234 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
235 	hlist_add_head_rcu(&dev->index_hlist,
236 			   dev_index_hash(net, dev->ifindex));
237 	write_unlock_bh(&dev_base_lock);
238 	return 0;
239 }
240 
241 /* Device list removal
242  * caller must respect a RCU grace period before freeing/reusing dev
243  */
244 static void unlist_netdevice(struct net_device *dev)
245 {
246 	ASSERT_RTNL();
247 
248 	/* Unlink dev from the device chain */
249 	write_lock_bh(&dev_base_lock);
250 	list_del_rcu(&dev->dev_list);
251 	hlist_del_rcu(&dev->name_hlist);
252 	hlist_del_rcu(&dev->index_hlist);
253 	write_unlock_bh(&dev_base_lock);
254 }
255 
256 /*
257  *	Our notifier list
258  */
259 
260 static RAW_NOTIFIER_HEAD(netdev_chain);
261 
262 /*
263  *	Device drivers call our routines to queue packets here. We empty the
264  *	queue in the local softnet handler.
265  */
266 
267 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
268 EXPORT_PER_CPU_SYMBOL(softnet_data);
269 
270 #ifdef CONFIG_LOCKDEP
271 /*
272  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
273  * according to dev->type
274  */
275 static const unsigned short netdev_lock_type[] =
276 	{ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
277 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
278 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
279 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
280 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
281 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
282 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
283 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
284 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
285 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
286 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
287 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
288 	 ARPHRD_FCFABRIC, ARPHRD_IEEE802_TR, ARPHRD_IEEE80211,
289 	 ARPHRD_IEEE80211_PRISM, ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET,
290 	 ARPHRD_PHONET_PIPE, ARPHRD_IEEE802154,
291 	 ARPHRD_VOID, ARPHRD_NONE};
292 
293 static const char *const netdev_lock_name[] =
294 	{"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
295 	 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
296 	 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
297 	 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
298 	 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
299 	 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
300 	 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
301 	 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
302 	 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
303 	 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
304 	 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
305 	 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
306 	 "_xmit_FCFABRIC", "_xmit_IEEE802_TR", "_xmit_IEEE80211",
307 	 "_xmit_IEEE80211_PRISM", "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET",
308 	 "_xmit_PHONET_PIPE", "_xmit_IEEE802154",
309 	 "_xmit_VOID", "_xmit_NONE"};
310 
311 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
312 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
313 
314 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
315 {
316 	int i;
317 
318 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
319 		if (netdev_lock_type[i] == dev_type)
320 			return i;
321 	/* the last key is used by default */
322 	return ARRAY_SIZE(netdev_lock_type) - 1;
323 }
324 
325 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
326 						 unsigned short dev_type)
327 {
328 	int i;
329 
330 	i = netdev_lock_pos(dev_type);
331 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
332 				   netdev_lock_name[i]);
333 }
334 
335 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
336 {
337 	int i;
338 
339 	i = netdev_lock_pos(dev->type);
340 	lockdep_set_class_and_name(&dev->addr_list_lock,
341 				   &netdev_addr_lock_key[i],
342 				   netdev_lock_name[i]);
343 }
344 #else
345 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
346 						 unsigned short dev_type)
347 {
348 }
349 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
350 {
351 }
352 #endif
353 
354 /*******************************************************************************
355 
356 		Protocol management and registration routines
357 
358 *******************************************************************************/
359 
360 /*
361  *	Add a protocol ID to the list. Now that the input handler is
362  *	smarter we can dispense with all the messy stuff that used to be
363  *	here.
364  *
365  *	BEWARE!!! Protocol handlers, mangling input packets,
366  *	MUST BE last in hash buckets and checking protocol handlers
367  *	MUST start from promiscuous ptype_all chain in net_bh.
368  *	It is true now, do not change it.
369  *	Explanation follows: if protocol handler, mangling packet, will
370  *	be the first on list, it is not able to sense, that packet
371  *	is cloned and should be copied-on-write, so that it will
372  *	change it and subsequent readers will get broken packet.
373  *							--ANK (980803)
374  */
375 
376 /**
377  *	dev_add_pack - add packet handler
378  *	@pt: packet type declaration
379  *
380  *	Add a protocol handler to the networking stack. The passed &packet_type
381  *	is linked into kernel lists and may not be freed until it has been
382  *	removed from the kernel lists.
383  *
384  *	This call does not sleep therefore it can not
385  *	guarantee all CPU's that are in middle of receiving packets
386  *	will see the new packet type (until the next received packet).
387  */
388 
389 void dev_add_pack(struct packet_type *pt)
390 {
391 	int hash;
392 
393 	spin_lock_bh(&ptype_lock);
394 	if (pt->type == htons(ETH_P_ALL))
395 		list_add_rcu(&pt->list, &ptype_all);
396 	else {
397 		hash = ntohs(pt->type) & PTYPE_HASH_MASK;
398 		list_add_rcu(&pt->list, &ptype_base[hash]);
399 	}
400 	spin_unlock_bh(&ptype_lock);
401 }
402 EXPORT_SYMBOL(dev_add_pack);
403 
404 /**
405  *	__dev_remove_pack	 - remove packet handler
406  *	@pt: packet type declaration
407  *
408  *	Remove a protocol handler that was previously added to the kernel
409  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
410  *	from the kernel lists and can be freed or reused once this function
411  *	returns.
412  *
413  *      The packet type might still be in use by receivers
414  *	and must not be freed until after all the CPU's have gone
415  *	through a quiescent state.
416  */
417 void __dev_remove_pack(struct packet_type *pt)
418 {
419 	struct list_head *head;
420 	struct packet_type *pt1;
421 
422 	spin_lock_bh(&ptype_lock);
423 
424 	if (pt->type == htons(ETH_P_ALL))
425 		head = &ptype_all;
426 	else
427 		head = &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
428 
429 	list_for_each_entry(pt1, head, list) {
430 		if (pt == pt1) {
431 			list_del_rcu(&pt->list);
432 			goto out;
433 		}
434 	}
435 
436 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
437 out:
438 	spin_unlock_bh(&ptype_lock);
439 }
440 EXPORT_SYMBOL(__dev_remove_pack);
441 
442 /**
443  *	dev_remove_pack	 - remove packet handler
444  *	@pt: packet type declaration
445  *
446  *	Remove a protocol handler that was previously added to the kernel
447  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
448  *	from the kernel lists and can be freed or reused once this function
449  *	returns.
450  *
451  *	This call sleeps to guarantee that no CPU is looking at the packet
452  *	type after return.
453  */
454 void dev_remove_pack(struct packet_type *pt)
455 {
456 	__dev_remove_pack(pt);
457 
458 	synchronize_net();
459 }
460 EXPORT_SYMBOL(dev_remove_pack);
461 
462 /******************************************************************************
463 
464 		      Device Boot-time Settings Routines
465 
466 *******************************************************************************/
467 
468 /* Boot time configuration table */
469 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
470 
471 /**
472  *	netdev_boot_setup_add	- add new setup entry
473  *	@name: name of the device
474  *	@map: configured settings for the device
475  *
476  *	Adds new setup entry to the dev_boot_setup list.  The function
477  *	returns 0 on error and 1 on success.  This is a generic routine to
478  *	all netdevices.
479  */
480 static int netdev_boot_setup_add(char *name, struct ifmap *map)
481 {
482 	struct netdev_boot_setup *s;
483 	int i;
484 
485 	s = dev_boot_setup;
486 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
487 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
488 			memset(s[i].name, 0, sizeof(s[i].name));
489 			strlcpy(s[i].name, name, IFNAMSIZ);
490 			memcpy(&s[i].map, map, sizeof(s[i].map));
491 			break;
492 		}
493 	}
494 
495 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
496 }
497 
498 /**
499  *	netdev_boot_setup_check	- check boot time settings
500  *	@dev: the netdevice
501  *
502  * 	Check boot time settings for the device.
503  *	The found settings are set for the device to be used
504  *	later in the device probing.
505  *	Returns 0 if no settings found, 1 if they are.
506  */
507 int netdev_boot_setup_check(struct net_device *dev)
508 {
509 	struct netdev_boot_setup *s = dev_boot_setup;
510 	int i;
511 
512 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
513 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
514 		    !strcmp(dev->name, s[i].name)) {
515 			dev->irq 	= s[i].map.irq;
516 			dev->base_addr 	= s[i].map.base_addr;
517 			dev->mem_start 	= s[i].map.mem_start;
518 			dev->mem_end 	= s[i].map.mem_end;
519 			return 1;
520 		}
521 	}
522 	return 0;
523 }
524 EXPORT_SYMBOL(netdev_boot_setup_check);
525 
526 
527 /**
528  *	netdev_boot_base	- get address from boot time settings
529  *	@prefix: prefix for network device
530  *	@unit: id for network device
531  *
532  * 	Check boot time settings for the base address of device.
533  *	The found settings are set for the device to be used
534  *	later in the device probing.
535  *	Returns 0 if no settings found.
536  */
537 unsigned long netdev_boot_base(const char *prefix, int unit)
538 {
539 	const struct netdev_boot_setup *s = dev_boot_setup;
540 	char name[IFNAMSIZ];
541 	int i;
542 
543 	sprintf(name, "%s%d", prefix, unit);
544 
545 	/*
546 	 * If device already registered then return base of 1
547 	 * to indicate not to probe for this interface
548 	 */
549 	if (__dev_get_by_name(&init_net, name))
550 		return 1;
551 
552 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
553 		if (!strcmp(name, s[i].name))
554 			return s[i].map.base_addr;
555 	return 0;
556 }
557 
558 /*
559  * Saves at boot time configured settings for any netdevice.
560  */
561 int __init netdev_boot_setup(char *str)
562 {
563 	int ints[5];
564 	struct ifmap map;
565 
566 	str = get_options(str, ARRAY_SIZE(ints), ints);
567 	if (!str || !*str)
568 		return 0;
569 
570 	/* Save settings */
571 	memset(&map, 0, sizeof(map));
572 	if (ints[0] > 0)
573 		map.irq = ints[1];
574 	if (ints[0] > 1)
575 		map.base_addr = ints[2];
576 	if (ints[0] > 2)
577 		map.mem_start = ints[3];
578 	if (ints[0] > 3)
579 		map.mem_end = ints[4];
580 
581 	/* Add new entry to the list */
582 	return netdev_boot_setup_add(str, &map);
583 }
584 
585 __setup("netdev=", netdev_boot_setup);
586 
587 /*******************************************************************************
588 
589 			    Device Interface Subroutines
590 
591 *******************************************************************************/
592 
593 /**
594  *	__dev_get_by_name	- find a device by its name
595  *	@net: the applicable net namespace
596  *	@name: name to find
597  *
598  *	Find an interface by name. Must be called under RTNL semaphore
599  *	or @dev_base_lock. If the name is found a pointer to the device
600  *	is returned. If the name is not found then %NULL is returned. The
601  *	reference counters are not incremented so the caller must be
602  *	careful with locks.
603  */
604 
605 struct net_device *__dev_get_by_name(struct net *net, const char *name)
606 {
607 	struct hlist_node *p;
608 	struct net_device *dev;
609 	struct hlist_head *head = dev_name_hash(net, name);
610 
611 	hlist_for_each_entry(dev, p, head, name_hlist)
612 		if (!strncmp(dev->name, name, IFNAMSIZ))
613 			return dev;
614 
615 	return NULL;
616 }
617 EXPORT_SYMBOL(__dev_get_by_name);
618 
619 /**
620  *	dev_get_by_name_rcu	- find a device by its name
621  *	@net: the applicable net namespace
622  *	@name: name to find
623  *
624  *	Find an interface by name.
625  *	If the name is found a pointer to the device is returned.
626  * 	If the name is not found then %NULL is returned.
627  *	The reference counters are not incremented so the caller must be
628  *	careful with locks. The caller must hold RCU lock.
629  */
630 
631 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
632 {
633 	struct hlist_node *p;
634 	struct net_device *dev;
635 	struct hlist_head *head = dev_name_hash(net, name);
636 
637 	hlist_for_each_entry_rcu(dev, p, head, name_hlist)
638 		if (!strncmp(dev->name, name, IFNAMSIZ))
639 			return dev;
640 
641 	return NULL;
642 }
643 EXPORT_SYMBOL(dev_get_by_name_rcu);
644 
645 /**
646  *	dev_get_by_name		- find a device by its name
647  *	@net: the applicable net namespace
648  *	@name: name to find
649  *
650  *	Find an interface by name. This can be called from any
651  *	context and does its own locking. The returned handle has
652  *	the usage count incremented and the caller must use dev_put() to
653  *	release it when it is no longer needed. %NULL is returned if no
654  *	matching device is found.
655  */
656 
657 struct net_device *dev_get_by_name(struct net *net, const char *name)
658 {
659 	struct net_device *dev;
660 
661 	rcu_read_lock();
662 	dev = dev_get_by_name_rcu(net, name);
663 	if (dev)
664 		dev_hold(dev);
665 	rcu_read_unlock();
666 	return dev;
667 }
668 EXPORT_SYMBOL(dev_get_by_name);
669 
670 /**
671  *	__dev_get_by_index - find a device by its ifindex
672  *	@net: the applicable net namespace
673  *	@ifindex: index of device
674  *
675  *	Search for an interface by index. Returns %NULL if the device
676  *	is not found or a pointer to the device. The device has not
677  *	had its reference counter increased so the caller must be careful
678  *	about locking. The caller must hold either the RTNL semaphore
679  *	or @dev_base_lock.
680  */
681 
682 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
683 {
684 	struct hlist_node *p;
685 	struct net_device *dev;
686 	struct hlist_head *head = dev_index_hash(net, ifindex);
687 
688 	hlist_for_each_entry(dev, p, head, index_hlist)
689 		if (dev->ifindex == ifindex)
690 			return dev;
691 
692 	return NULL;
693 }
694 EXPORT_SYMBOL(__dev_get_by_index);
695 
696 /**
697  *	dev_get_by_index_rcu - find a device by its ifindex
698  *	@net: the applicable net namespace
699  *	@ifindex: index of device
700  *
701  *	Search for an interface by index. Returns %NULL if the device
702  *	is not found or a pointer to the device. The device has not
703  *	had its reference counter increased so the caller must be careful
704  *	about locking. The caller must hold RCU lock.
705  */
706 
707 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
708 {
709 	struct hlist_node *p;
710 	struct net_device *dev;
711 	struct hlist_head *head = dev_index_hash(net, ifindex);
712 
713 	hlist_for_each_entry_rcu(dev, p, head, index_hlist)
714 		if (dev->ifindex == ifindex)
715 			return dev;
716 
717 	return NULL;
718 }
719 EXPORT_SYMBOL(dev_get_by_index_rcu);
720 
721 
722 /**
723  *	dev_get_by_index - find a device by its ifindex
724  *	@net: the applicable net namespace
725  *	@ifindex: index of device
726  *
727  *	Search for an interface by index. Returns NULL if the device
728  *	is not found or a pointer to the device. The device returned has
729  *	had a reference added and the pointer is safe until the user calls
730  *	dev_put to indicate they have finished with it.
731  */
732 
733 struct net_device *dev_get_by_index(struct net *net, int ifindex)
734 {
735 	struct net_device *dev;
736 
737 	rcu_read_lock();
738 	dev = dev_get_by_index_rcu(net, ifindex);
739 	if (dev)
740 		dev_hold(dev);
741 	rcu_read_unlock();
742 	return dev;
743 }
744 EXPORT_SYMBOL(dev_get_by_index);
745 
746 /**
747  *	dev_getbyhwaddr - find a device by its hardware address
748  *	@net: the applicable net namespace
749  *	@type: media type of device
750  *	@ha: hardware address
751  *
752  *	Search for an interface by MAC address. Returns NULL if the device
753  *	is not found or a pointer to the device. The caller must hold the
754  *	rtnl semaphore. The returned device has not had its ref count increased
755  *	and the caller must therefore be careful about locking
756  *
757  *	BUGS:
758  *	If the API was consistent this would be __dev_get_by_hwaddr
759  */
760 
761 struct net_device *dev_getbyhwaddr(struct net *net, unsigned short type, char *ha)
762 {
763 	struct net_device *dev;
764 
765 	ASSERT_RTNL();
766 
767 	for_each_netdev(net, dev)
768 		if (dev->type == type &&
769 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
770 			return dev;
771 
772 	return NULL;
773 }
774 EXPORT_SYMBOL(dev_getbyhwaddr);
775 
776 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
777 {
778 	struct net_device *dev;
779 
780 	ASSERT_RTNL();
781 	for_each_netdev(net, dev)
782 		if (dev->type == type)
783 			return dev;
784 
785 	return NULL;
786 }
787 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
788 
789 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
790 {
791 	struct net_device *dev, *ret = NULL;
792 
793 	rcu_read_lock();
794 	for_each_netdev_rcu(net, dev)
795 		if (dev->type == type) {
796 			dev_hold(dev);
797 			ret = dev;
798 			break;
799 		}
800 	rcu_read_unlock();
801 	return ret;
802 }
803 EXPORT_SYMBOL(dev_getfirstbyhwtype);
804 
805 /**
806  *	dev_get_by_flags - find any device with given flags
807  *	@net: the applicable net namespace
808  *	@if_flags: IFF_* values
809  *	@mask: bitmask of bits in if_flags to check
810  *
811  *	Search for any interface with the given flags. Returns NULL if a device
812  *	is not found or a pointer to the device. The device returned has
813  *	had a reference added and the pointer is safe until the user calls
814  *	dev_put to indicate they have finished with it.
815  */
816 
817 struct net_device *dev_get_by_flags(struct net *net, unsigned short if_flags,
818 				    unsigned short mask)
819 {
820 	struct net_device *dev, *ret;
821 
822 	ret = NULL;
823 	rcu_read_lock();
824 	for_each_netdev_rcu(net, dev) {
825 		if (((dev->flags ^ if_flags) & mask) == 0) {
826 			dev_hold(dev);
827 			ret = dev;
828 			break;
829 		}
830 	}
831 	rcu_read_unlock();
832 	return ret;
833 }
834 EXPORT_SYMBOL(dev_get_by_flags);
835 
836 /**
837  *	dev_valid_name - check if name is okay for network device
838  *	@name: name string
839  *
840  *	Network device names need to be valid file names to
841  *	to allow sysfs to work.  We also disallow any kind of
842  *	whitespace.
843  */
844 int dev_valid_name(const char *name)
845 {
846 	if (*name == '\0')
847 		return 0;
848 	if (strlen(name) >= IFNAMSIZ)
849 		return 0;
850 	if (!strcmp(name, ".") || !strcmp(name, ".."))
851 		return 0;
852 
853 	while (*name) {
854 		if (*name == '/' || isspace(*name))
855 			return 0;
856 		name++;
857 	}
858 	return 1;
859 }
860 EXPORT_SYMBOL(dev_valid_name);
861 
862 /**
863  *	__dev_alloc_name - allocate a name for a device
864  *	@net: network namespace to allocate the device name in
865  *	@name: name format string
866  *	@buf:  scratch buffer and result name string
867  *
868  *	Passed a format string - eg "lt%d" it will try and find a suitable
869  *	id. It scans list of devices to build up a free map, then chooses
870  *	the first empty slot. The caller must hold the dev_base or rtnl lock
871  *	while allocating the name and adding the device in order to avoid
872  *	duplicates.
873  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
874  *	Returns the number of the unit assigned or a negative errno code.
875  */
876 
877 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
878 {
879 	int i = 0;
880 	const char *p;
881 	const int max_netdevices = 8*PAGE_SIZE;
882 	unsigned long *inuse;
883 	struct net_device *d;
884 
885 	p = strnchr(name, IFNAMSIZ-1, '%');
886 	if (p) {
887 		/*
888 		 * Verify the string as this thing may have come from
889 		 * the user.  There must be either one "%d" and no other "%"
890 		 * characters.
891 		 */
892 		if (p[1] != 'd' || strchr(p + 2, '%'))
893 			return -EINVAL;
894 
895 		/* Use one page as a bit array of possible slots */
896 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
897 		if (!inuse)
898 			return -ENOMEM;
899 
900 		for_each_netdev(net, d) {
901 			if (!sscanf(d->name, name, &i))
902 				continue;
903 			if (i < 0 || i >= max_netdevices)
904 				continue;
905 
906 			/*  avoid cases where sscanf is not exact inverse of printf */
907 			snprintf(buf, IFNAMSIZ, name, i);
908 			if (!strncmp(buf, d->name, IFNAMSIZ))
909 				set_bit(i, inuse);
910 		}
911 
912 		i = find_first_zero_bit(inuse, max_netdevices);
913 		free_page((unsigned long) inuse);
914 	}
915 
916 	if (buf != name)
917 		snprintf(buf, IFNAMSIZ, name, i);
918 	if (!__dev_get_by_name(net, buf))
919 		return i;
920 
921 	/* It is possible to run out of possible slots
922 	 * when the name is long and there isn't enough space left
923 	 * for the digits, or if all bits are used.
924 	 */
925 	return -ENFILE;
926 }
927 
928 /**
929  *	dev_alloc_name - allocate a name for a device
930  *	@dev: device
931  *	@name: name format string
932  *
933  *	Passed a format string - eg "lt%d" it will try and find a suitable
934  *	id. It scans list of devices to build up a free map, then chooses
935  *	the first empty slot. The caller must hold the dev_base or rtnl lock
936  *	while allocating the name and adding the device in order to avoid
937  *	duplicates.
938  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
939  *	Returns the number of the unit assigned or a negative errno code.
940  */
941 
942 int dev_alloc_name(struct net_device *dev, const char *name)
943 {
944 	char buf[IFNAMSIZ];
945 	struct net *net;
946 	int ret;
947 
948 	BUG_ON(!dev_net(dev));
949 	net = dev_net(dev);
950 	ret = __dev_alloc_name(net, name, buf);
951 	if (ret >= 0)
952 		strlcpy(dev->name, buf, IFNAMSIZ);
953 	return ret;
954 }
955 EXPORT_SYMBOL(dev_alloc_name);
956 
957 static int dev_get_valid_name(struct net_device *dev, const char *name, bool fmt)
958 {
959 	struct net *net;
960 
961 	BUG_ON(!dev_net(dev));
962 	net = dev_net(dev);
963 
964 	if (!dev_valid_name(name))
965 		return -EINVAL;
966 
967 	if (fmt && strchr(name, '%'))
968 		return dev_alloc_name(dev, name);
969 	else if (__dev_get_by_name(net, name))
970 		return -EEXIST;
971 	else if (dev->name != name)
972 		strlcpy(dev->name, name, IFNAMSIZ);
973 
974 	return 0;
975 }
976 
977 /**
978  *	dev_change_name - change name of a device
979  *	@dev: device
980  *	@newname: name (or format string) must be at least IFNAMSIZ
981  *
982  *	Change name of a device, can pass format strings "eth%d".
983  *	for wildcarding.
984  */
985 int dev_change_name(struct net_device *dev, const char *newname)
986 {
987 	char oldname[IFNAMSIZ];
988 	int err = 0;
989 	int ret;
990 	struct net *net;
991 
992 	ASSERT_RTNL();
993 	BUG_ON(!dev_net(dev));
994 
995 	net = dev_net(dev);
996 	if (dev->flags & IFF_UP)
997 		return -EBUSY;
998 
999 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
1000 		return 0;
1001 
1002 	memcpy(oldname, dev->name, IFNAMSIZ);
1003 
1004 	err = dev_get_valid_name(dev, newname, 1);
1005 	if (err < 0)
1006 		return err;
1007 
1008 rollback:
1009 	ret = device_rename(&dev->dev, dev->name);
1010 	if (ret) {
1011 		memcpy(dev->name, oldname, IFNAMSIZ);
1012 		return ret;
1013 	}
1014 
1015 	write_lock_bh(&dev_base_lock);
1016 	hlist_del(&dev->name_hlist);
1017 	write_unlock_bh(&dev_base_lock);
1018 
1019 	synchronize_rcu();
1020 
1021 	write_lock_bh(&dev_base_lock);
1022 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1023 	write_unlock_bh(&dev_base_lock);
1024 
1025 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1026 	ret = notifier_to_errno(ret);
1027 
1028 	if (ret) {
1029 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1030 		if (err >= 0) {
1031 			err = ret;
1032 			memcpy(dev->name, oldname, IFNAMSIZ);
1033 			goto rollback;
1034 		} else {
1035 			printk(KERN_ERR
1036 			       "%s: name change rollback failed: %d.\n",
1037 			       dev->name, ret);
1038 		}
1039 	}
1040 
1041 	return err;
1042 }
1043 
1044 /**
1045  *	dev_set_alias - change ifalias of a device
1046  *	@dev: device
1047  *	@alias: name up to IFALIASZ
1048  *	@len: limit of bytes to copy from info
1049  *
1050  *	Set ifalias for a device,
1051  */
1052 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1053 {
1054 	ASSERT_RTNL();
1055 
1056 	if (len >= IFALIASZ)
1057 		return -EINVAL;
1058 
1059 	if (!len) {
1060 		if (dev->ifalias) {
1061 			kfree(dev->ifalias);
1062 			dev->ifalias = NULL;
1063 		}
1064 		return 0;
1065 	}
1066 
1067 	dev->ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1068 	if (!dev->ifalias)
1069 		return -ENOMEM;
1070 
1071 	strlcpy(dev->ifalias, alias, len+1);
1072 	return len;
1073 }
1074 
1075 
1076 /**
1077  *	netdev_features_change - device changes features
1078  *	@dev: device to cause notification
1079  *
1080  *	Called to indicate a device has changed features.
1081  */
1082 void netdev_features_change(struct net_device *dev)
1083 {
1084 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1085 }
1086 EXPORT_SYMBOL(netdev_features_change);
1087 
1088 /**
1089  *	netdev_state_change - device changes state
1090  *	@dev: device to cause notification
1091  *
1092  *	Called to indicate a device has changed state. This function calls
1093  *	the notifier chains for netdev_chain and sends a NEWLINK message
1094  *	to the routing socket.
1095  */
1096 void netdev_state_change(struct net_device *dev)
1097 {
1098 	if (dev->flags & IFF_UP) {
1099 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
1100 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1101 	}
1102 }
1103 EXPORT_SYMBOL(netdev_state_change);
1104 
1105 int netdev_bonding_change(struct net_device *dev, unsigned long event)
1106 {
1107 	return call_netdevice_notifiers(event, dev);
1108 }
1109 EXPORT_SYMBOL(netdev_bonding_change);
1110 
1111 /**
1112  *	dev_load 	- load a network module
1113  *	@net: the applicable net namespace
1114  *	@name: name of interface
1115  *
1116  *	If a network interface is not present and the process has suitable
1117  *	privileges this function loads the module. If module loading is not
1118  *	available in this kernel then it becomes a nop.
1119  */
1120 
1121 void dev_load(struct net *net, const char *name)
1122 {
1123 	struct net_device *dev;
1124 
1125 	rcu_read_lock();
1126 	dev = dev_get_by_name_rcu(net, name);
1127 	rcu_read_unlock();
1128 
1129 	if (!dev && capable(CAP_NET_ADMIN))
1130 		request_module("%s", name);
1131 }
1132 EXPORT_SYMBOL(dev_load);
1133 
1134 static int __dev_open(struct net_device *dev)
1135 {
1136 	const struct net_device_ops *ops = dev->netdev_ops;
1137 	int ret;
1138 
1139 	ASSERT_RTNL();
1140 
1141 	/*
1142 	 *	Is it even present?
1143 	 */
1144 	if (!netif_device_present(dev))
1145 		return -ENODEV;
1146 
1147 	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1148 	ret = notifier_to_errno(ret);
1149 	if (ret)
1150 		return ret;
1151 
1152 	/*
1153 	 *	Call device private open method
1154 	 */
1155 	set_bit(__LINK_STATE_START, &dev->state);
1156 
1157 	if (ops->ndo_validate_addr)
1158 		ret = ops->ndo_validate_addr(dev);
1159 
1160 	if (!ret && ops->ndo_open)
1161 		ret = ops->ndo_open(dev);
1162 
1163 	/*
1164 	 *	If it went open OK then:
1165 	 */
1166 
1167 	if (ret)
1168 		clear_bit(__LINK_STATE_START, &dev->state);
1169 	else {
1170 		/*
1171 		 *	Set the flags.
1172 		 */
1173 		dev->flags |= IFF_UP;
1174 
1175 		/*
1176 		 *	Enable NET_DMA
1177 		 */
1178 		net_dmaengine_get();
1179 
1180 		/*
1181 		 *	Initialize multicasting status
1182 		 */
1183 		dev_set_rx_mode(dev);
1184 
1185 		/*
1186 		 *	Wakeup transmit queue engine
1187 		 */
1188 		dev_activate(dev);
1189 	}
1190 
1191 	return ret;
1192 }
1193 
1194 /**
1195  *	dev_open	- prepare an interface for use.
1196  *	@dev:	device to open
1197  *
1198  *	Takes a device from down to up state. The device's private open
1199  *	function is invoked and then the multicast lists are loaded. Finally
1200  *	the device is moved into the up state and a %NETDEV_UP message is
1201  *	sent to the netdev notifier chain.
1202  *
1203  *	Calling this function on an active interface is a nop. On a failure
1204  *	a negative errno code is returned.
1205  */
1206 int dev_open(struct net_device *dev)
1207 {
1208 	int ret;
1209 
1210 	/*
1211 	 *	Is it already up?
1212 	 */
1213 	if (dev->flags & IFF_UP)
1214 		return 0;
1215 
1216 	/*
1217 	 *	Open device
1218 	 */
1219 	ret = __dev_open(dev);
1220 	if (ret < 0)
1221 		return ret;
1222 
1223 	/*
1224 	 *	... and announce new interface.
1225 	 */
1226 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1227 	call_netdevice_notifiers(NETDEV_UP, dev);
1228 
1229 	return ret;
1230 }
1231 EXPORT_SYMBOL(dev_open);
1232 
1233 static int __dev_close(struct net_device *dev)
1234 {
1235 	const struct net_device_ops *ops = dev->netdev_ops;
1236 
1237 	ASSERT_RTNL();
1238 	might_sleep();
1239 
1240 	/*
1241 	 *	Tell people we are going down, so that they can
1242 	 *	prepare to death, when device is still operating.
1243 	 */
1244 	call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1245 
1246 	clear_bit(__LINK_STATE_START, &dev->state);
1247 
1248 	/* Synchronize to scheduled poll. We cannot touch poll list,
1249 	 * it can be even on different cpu. So just clear netif_running().
1250 	 *
1251 	 * dev->stop() will invoke napi_disable() on all of it's
1252 	 * napi_struct instances on this device.
1253 	 */
1254 	smp_mb__after_clear_bit(); /* Commit netif_running(). */
1255 
1256 	dev_deactivate(dev);
1257 
1258 	/*
1259 	 *	Call the device specific close. This cannot fail.
1260 	 *	Only if device is UP
1261 	 *
1262 	 *	We allow it to be called even after a DETACH hot-plug
1263 	 *	event.
1264 	 */
1265 	if (ops->ndo_stop)
1266 		ops->ndo_stop(dev);
1267 
1268 	/*
1269 	 *	Device is now down.
1270 	 */
1271 
1272 	dev->flags &= ~IFF_UP;
1273 
1274 	/*
1275 	 *	Shutdown NET_DMA
1276 	 */
1277 	net_dmaengine_put();
1278 
1279 	return 0;
1280 }
1281 
1282 /**
1283  *	dev_close - shutdown an interface.
1284  *	@dev: device to shutdown
1285  *
1286  *	This function moves an active device into down state. A
1287  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1288  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1289  *	chain.
1290  */
1291 int dev_close(struct net_device *dev)
1292 {
1293 	if (!(dev->flags & IFF_UP))
1294 		return 0;
1295 
1296 	__dev_close(dev);
1297 
1298 	/*
1299 	 * Tell people we are down
1300 	 */
1301 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1302 	call_netdevice_notifiers(NETDEV_DOWN, dev);
1303 
1304 	return 0;
1305 }
1306 EXPORT_SYMBOL(dev_close);
1307 
1308 
1309 /**
1310  *	dev_disable_lro - disable Large Receive Offload on a device
1311  *	@dev: device
1312  *
1313  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1314  *	called under RTNL.  This is needed if received packets may be
1315  *	forwarded to another interface.
1316  */
1317 void dev_disable_lro(struct net_device *dev)
1318 {
1319 	if (dev->ethtool_ops && dev->ethtool_ops->get_flags &&
1320 	    dev->ethtool_ops->set_flags) {
1321 		u32 flags = dev->ethtool_ops->get_flags(dev);
1322 		if (flags & ETH_FLAG_LRO) {
1323 			flags &= ~ETH_FLAG_LRO;
1324 			dev->ethtool_ops->set_flags(dev, flags);
1325 		}
1326 	}
1327 	WARN_ON(dev->features & NETIF_F_LRO);
1328 }
1329 EXPORT_SYMBOL(dev_disable_lro);
1330 
1331 
1332 static int dev_boot_phase = 1;
1333 
1334 /*
1335  *	Device change register/unregister. These are not inline or static
1336  *	as we export them to the world.
1337  */
1338 
1339 /**
1340  *	register_netdevice_notifier - register a network notifier block
1341  *	@nb: notifier
1342  *
1343  *	Register a notifier to be called when network device events occur.
1344  *	The notifier passed is linked into the kernel structures and must
1345  *	not be reused until it has been unregistered. A negative errno code
1346  *	is returned on a failure.
1347  *
1348  * 	When registered all registration and up events are replayed
1349  *	to the new notifier to allow device to have a race free
1350  *	view of the network device list.
1351  */
1352 
1353 int register_netdevice_notifier(struct notifier_block *nb)
1354 {
1355 	struct net_device *dev;
1356 	struct net_device *last;
1357 	struct net *net;
1358 	int err;
1359 
1360 	rtnl_lock();
1361 	err = raw_notifier_chain_register(&netdev_chain, nb);
1362 	if (err)
1363 		goto unlock;
1364 	if (dev_boot_phase)
1365 		goto unlock;
1366 	for_each_net(net) {
1367 		for_each_netdev(net, dev) {
1368 			err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1369 			err = notifier_to_errno(err);
1370 			if (err)
1371 				goto rollback;
1372 
1373 			if (!(dev->flags & IFF_UP))
1374 				continue;
1375 
1376 			nb->notifier_call(nb, NETDEV_UP, dev);
1377 		}
1378 	}
1379 
1380 unlock:
1381 	rtnl_unlock();
1382 	return err;
1383 
1384 rollback:
1385 	last = dev;
1386 	for_each_net(net) {
1387 		for_each_netdev(net, dev) {
1388 			if (dev == last)
1389 				break;
1390 
1391 			if (dev->flags & IFF_UP) {
1392 				nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1393 				nb->notifier_call(nb, NETDEV_DOWN, dev);
1394 			}
1395 			nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1396 			nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
1397 		}
1398 	}
1399 
1400 	raw_notifier_chain_unregister(&netdev_chain, nb);
1401 	goto unlock;
1402 }
1403 EXPORT_SYMBOL(register_netdevice_notifier);
1404 
1405 /**
1406  *	unregister_netdevice_notifier - unregister a network notifier block
1407  *	@nb: notifier
1408  *
1409  *	Unregister a notifier previously registered by
1410  *	register_netdevice_notifier(). The notifier is unlinked into the
1411  *	kernel structures and may then be reused. A negative errno code
1412  *	is returned on a failure.
1413  */
1414 
1415 int unregister_netdevice_notifier(struct notifier_block *nb)
1416 {
1417 	int err;
1418 
1419 	rtnl_lock();
1420 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1421 	rtnl_unlock();
1422 	return err;
1423 }
1424 EXPORT_SYMBOL(unregister_netdevice_notifier);
1425 
1426 /**
1427  *	call_netdevice_notifiers - call all network notifier blocks
1428  *      @val: value passed unmodified to notifier function
1429  *      @dev: net_device pointer passed unmodified to notifier function
1430  *
1431  *	Call all network notifier blocks.  Parameters and return value
1432  *	are as for raw_notifier_call_chain().
1433  */
1434 
1435 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1436 {
1437 	ASSERT_RTNL();
1438 	return raw_notifier_call_chain(&netdev_chain, val, dev);
1439 }
1440 
1441 /* When > 0 there are consumers of rx skb time stamps */
1442 static atomic_t netstamp_needed = ATOMIC_INIT(0);
1443 
1444 void net_enable_timestamp(void)
1445 {
1446 	atomic_inc(&netstamp_needed);
1447 }
1448 EXPORT_SYMBOL(net_enable_timestamp);
1449 
1450 void net_disable_timestamp(void)
1451 {
1452 	atomic_dec(&netstamp_needed);
1453 }
1454 EXPORT_SYMBOL(net_disable_timestamp);
1455 
1456 static inline void net_timestamp_set(struct sk_buff *skb)
1457 {
1458 	if (atomic_read(&netstamp_needed))
1459 		__net_timestamp(skb);
1460 	else
1461 		skb->tstamp.tv64 = 0;
1462 }
1463 
1464 static inline void net_timestamp_check(struct sk_buff *skb)
1465 {
1466 	if (!skb->tstamp.tv64 && atomic_read(&netstamp_needed))
1467 		__net_timestamp(skb);
1468 }
1469 
1470 /**
1471  * dev_forward_skb - loopback an skb to another netif
1472  *
1473  * @dev: destination network device
1474  * @skb: buffer to forward
1475  *
1476  * return values:
1477  *	NET_RX_SUCCESS	(no congestion)
1478  *	NET_RX_DROP     (packet was dropped, but freed)
1479  *
1480  * dev_forward_skb can be used for injecting an skb from the
1481  * start_xmit function of one device into the receive queue
1482  * of another device.
1483  *
1484  * The receiving device may be in another namespace, so
1485  * we have to clear all information in the skb that could
1486  * impact namespace isolation.
1487  */
1488 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1489 {
1490 	skb_orphan(skb);
1491 
1492 	if (!(dev->flags & IFF_UP) ||
1493 	    (skb->len > (dev->mtu + dev->hard_header_len))) {
1494 		kfree_skb(skb);
1495 		return NET_RX_DROP;
1496 	}
1497 	skb_set_dev(skb, dev);
1498 	skb->tstamp.tv64 = 0;
1499 	skb->pkt_type = PACKET_HOST;
1500 	skb->protocol = eth_type_trans(skb, dev);
1501 	return netif_rx(skb);
1502 }
1503 EXPORT_SYMBOL_GPL(dev_forward_skb);
1504 
1505 /*
1506  *	Support routine. Sends outgoing frames to any network
1507  *	taps currently in use.
1508  */
1509 
1510 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1511 {
1512 	struct packet_type *ptype;
1513 
1514 #ifdef CONFIG_NET_CLS_ACT
1515 	if (!(skb->tstamp.tv64 && (G_TC_FROM(skb->tc_verd) & AT_INGRESS)))
1516 		net_timestamp_set(skb);
1517 #else
1518 	net_timestamp_set(skb);
1519 #endif
1520 
1521 	rcu_read_lock();
1522 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1523 		/* Never send packets back to the socket
1524 		 * they originated from - MvS (miquels@drinkel.ow.org)
1525 		 */
1526 		if ((ptype->dev == dev || !ptype->dev) &&
1527 		    (ptype->af_packet_priv == NULL ||
1528 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1529 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1530 			if (!skb2)
1531 				break;
1532 
1533 			/* skb->nh should be correctly
1534 			   set by sender, so that the second statement is
1535 			   just protection against buggy protocols.
1536 			 */
1537 			skb_reset_mac_header(skb2);
1538 
1539 			if (skb_network_header(skb2) < skb2->data ||
1540 			    skb2->network_header > skb2->tail) {
1541 				if (net_ratelimit())
1542 					printk(KERN_CRIT "protocol %04x is "
1543 					       "buggy, dev %s\n",
1544 					       skb2->protocol, dev->name);
1545 				skb_reset_network_header(skb2);
1546 			}
1547 
1548 			skb2->transport_header = skb2->network_header;
1549 			skb2->pkt_type = PACKET_OUTGOING;
1550 			ptype->func(skb2, skb->dev, ptype, skb->dev);
1551 		}
1552 	}
1553 	rcu_read_unlock();
1554 }
1555 
1556 
1557 static inline void __netif_reschedule(struct Qdisc *q)
1558 {
1559 	struct softnet_data *sd;
1560 	unsigned long flags;
1561 
1562 	local_irq_save(flags);
1563 	sd = &__get_cpu_var(softnet_data);
1564 	q->next_sched = NULL;
1565 	*sd->output_queue_tailp = q;
1566 	sd->output_queue_tailp = &q->next_sched;
1567 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
1568 	local_irq_restore(flags);
1569 }
1570 
1571 void __netif_schedule(struct Qdisc *q)
1572 {
1573 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
1574 		__netif_reschedule(q);
1575 }
1576 EXPORT_SYMBOL(__netif_schedule);
1577 
1578 void dev_kfree_skb_irq(struct sk_buff *skb)
1579 {
1580 	if (atomic_dec_and_test(&skb->users)) {
1581 		struct softnet_data *sd;
1582 		unsigned long flags;
1583 
1584 		local_irq_save(flags);
1585 		sd = &__get_cpu_var(softnet_data);
1586 		skb->next = sd->completion_queue;
1587 		sd->completion_queue = skb;
1588 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
1589 		local_irq_restore(flags);
1590 	}
1591 }
1592 EXPORT_SYMBOL(dev_kfree_skb_irq);
1593 
1594 void dev_kfree_skb_any(struct sk_buff *skb)
1595 {
1596 	if (in_irq() || irqs_disabled())
1597 		dev_kfree_skb_irq(skb);
1598 	else
1599 		dev_kfree_skb(skb);
1600 }
1601 EXPORT_SYMBOL(dev_kfree_skb_any);
1602 
1603 
1604 /**
1605  * netif_device_detach - mark device as removed
1606  * @dev: network device
1607  *
1608  * Mark device as removed from system and therefore no longer available.
1609  */
1610 void netif_device_detach(struct net_device *dev)
1611 {
1612 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
1613 	    netif_running(dev)) {
1614 		netif_tx_stop_all_queues(dev);
1615 	}
1616 }
1617 EXPORT_SYMBOL(netif_device_detach);
1618 
1619 /**
1620  * netif_device_attach - mark device as attached
1621  * @dev: network device
1622  *
1623  * Mark device as attached from system and restart if needed.
1624  */
1625 void netif_device_attach(struct net_device *dev)
1626 {
1627 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
1628 	    netif_running(dev)) {
1629 		netif_tx_wake_all_queues(dev);
1630 		__netdev_watchdog_up(dev);
1631 	}
1632 }
1633 EXPORT_SYMBOL(netif_device_attach);
1634 
1635 static bool can_checksum_protocol(unsigned long features, __be16 protocol)
1636 {
1637 	return ((features & NETIF_F_GEN_CSUM) ||
1638 		((features & NETIF_F_IP_CSUM) &&
1639 		 protocol == htons(ETH_P_IP)) ||
1640 		((features & NETIF_F_IPV6_CSUM) &&
1641 		 protocol == htons(ETH_P_IPV6)) ||
1642 		((features & NETIF_F_FCOE_CRC) &&
1643 		 protocol == htons(ETH_P_FCOE)));
1644 }
1645 
1646 static bool dev_can_checksum(struct net_device *dev, struct sk_buff *skb)
1647 {
1648 	if (can_checksum_protocol(dev->features, skb->protocol))
1649 		return true;
1650 
1651 	if (skb->protocol == htons(ETH_P_8021Q)) {
1652 		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
1653 		if (can_checksum_protocol(dev->features & dev->vlan_features,
1654 					  veh->h_vlan_encapsulated_proto))
1655 			return true;
1656 	}
1657 
1658 	return false;
1659 }
1660 
1661 /**
1662  * skb_dev_set -- assign a new device to a buffer
1663  * @skb: buffer for the new device
1664  * @dev: network device
1665  *
1666  * If an skb is owned by a device already, we have to reset
1667  * all data private to the namespace a device belongs to
1668  * before assigning it a new device.
1669  */
1670 #ifdef CONFIG_NET_NS
1671 void skb_set_dev(struct sk_buff *skb, struct net_device *dev)
1672 {
1673 	skb_dst_drop(skb);
1674 	if (skb->dev && !net_eq(dev_net(skb->dev), dev_net(dev))) {
1675 		secpath_reset(skb);
1676 		nf_reset(skb);
1677 		skb_init_secmark(skb);
1678 		skb->mark = 0;
1679 		skb->priority = 0;
1680 		skb->nf_trace = 0;
1681 		skb->ipvs_property = 0;
1682 #ifdef CONFIG_NET_SCHED
1683 		skb->tc_index = 0;
1684 #endif
1685 	}
1686 	skb->dev = dev;
1687 }
1688 EXPORT_SYMBOL(skb_set_dev);
1689 #endif /* CONFIG_NET_NS */
1690 
1691 /*
1692  * Invalidate hardware checksum when packet is to be mangled, and
1693  * complete checksum manually on outgoing path.
1694  */
1695 int skb_checksum_help(struct sk_buff *skb)
1696 {
1697 	__wsum csum;
1698 	int ret = 0, offset;
1699 
1700 	if (skb->ip_summed == CHECKSUM_COMPLETE)
1701 		goto out_set_summed;
1702 
1703 	if (unlikely(skb_shinfo(skb)->gso_size)) {
1704 		/* Let GSO fix up the checksum. */
1705 		goto out_set_summed;
1706 	}
1707 
1708 	offset = skb->csum_start - skb_headroom(skb);
1709 	BUG_ON(offset >= skb_headlen(skb));
1710 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
1711 
1712 	offset += skb->csum_offset;
1713 	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
1714 
1715 	if (skb_cloned(skb) &&
1716 	    !skb_clone_writable(skb, offset + sizeof(__sum16))) {
1717 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1718 		if (ret)
1719 			goto out;
1720 	}
1721 
1722 	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
1723 out_set_summed:
1724 	skb->ip_summed = CHECKSUM_NONE;
1725 out:
1726 	return ret;
1727 }
1728 EXPORT_SYMBOL(skb_checksum_help);
1729 
1730 /**
1731  *	skb_gso_segment - Perform segmentation on skb.
1732  *	@skb: buffer to segment
1733  *	@features: features for the output path (see dev->features)
1734  *
1735  *	This function segments the given skb and returns a list of segments.
1736  *
1737  *	It may return NULL if the skb requires no segmentation.  This is
1738  *	only possible when GSO is used for verifying header integrity.
1739  */
1740 struct sk_buff *skb_gso_segment(struct sk_buff *skb, int features)
1741 {
1742 	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
1743 	struct packet_type *ptype;
1744 	__be16 type = skb->protocol;
1745 	int err;
1746 
1747 	skb_reset_mac_header(skb);
1748 	skb->mac_len = skb->network_header - skb->mac_header;
1749 	__skb_pull(skb, skb->mac_len);
1750 
1751 	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1752 		struct net_device *dev = skb->dev;
1753 		struct ethtool_drvinfo info = {};
1754 
1755 		if (dev && dev->ethtool_ops && dev->ethtool_ops->get_drvinfo)
1756 			dev->ethtool_ops->get_drvinfo(dev, &info);
1757 
1758 		WARN(1, "%s: caps=(0x%lx, 0x%lx) len=%d data_len=%d "
1759 			"ip_summed=%d",
1760 		     info.driver, dev ? dev->features : 0L,
1761 		     skb->sk ? skb->sk->sk_route_caps : 0L,
1762 		     skb->len, skb->data_len, skb->ip_summed);
1763 
1764 		if (skb_header_cloned(skb) &&
1765 		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
1766 			return ERR_PTR(err);
1767 	}
1768 
1769 	rcu_read_lock();
1770 	list_for_each_entry_rcu(ptype,
1771 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
1772 		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
1773 			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1774 				err = ptype->gso_send_check(skb);
1775 				segs = ERR_PTR(err);
1776 				if (err || skb_gso_ok(skb, features))
1777 					break;
1778 				__skb_push(skb, (skb->data -
1779 						 skb_network_header(skb)));
1780 			}
1781 			segs = ptype->gso_segment(skb, features);
1782 			break;
1783 		}
1784 	}
1785 	rcu_read_unlock();
1786 
1787 	__skb_push(skb, skb->data - skb_mac_header(skb));
1788 
1789 	return segs;
1790 }
1791 EXPORT_SYMBOL(skb_gso_segment);
1792 
1793 /* Take action when hardware reception checksum errors are detected. */
1794 #ifdef CONFIG_BUG
1795 void netdev_rx_csum_fault(struct net_device *dev)
1796 {
1797 	if (net_ratelimit()) {
1798 		printk(KERN_ERR "%s: hw csum failure.\n",
1799 			dev ? dev->name : "<unknown>");
1800 		dump_stack();
1801 	}
1802 }
1803 EXPORT_SYMBOL(netdev_rx_csum_fault);
1804 #endif
1805 
1806 /* Actually, we should eliminate this check as soon as we know, that:
1807  * 1. IOMMU is present and allows to map all the memory.
1808  * 2. No high memory really exists on this machine.
1809  */
1810 
1811 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1812 {
1813 #ifdef CONFIG_HIGHMEM
1814 	int i;
1815 	if (!(dev->features & NETIF_F_HIGHDMA)) {
1816 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1817 			if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1818 				return 1;
1819 	}
1820 
1821 	if (PCI_DMA_BUS_IS_PHYS) {
1822 		struct device *pdev = dev->dev.parent;
1823 
1824 		if (!pdev)
1825 			return 0;
1826 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1827 			dma_addr_t addr = page_to_phys(skb_shinfo(skb)->frags[i].page);
1828 			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
1829 				return 1;
1830 		}
1831 	}
1832 #endif
1833 	return 0;
1834 }
1835 
1836 struct dev_gso_cb {
1837 	void (*destructor)(struct sk_buff *skb);
1838 };
1839 
1840 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
1841 
1842 static void dev_gso_skb_destructor(struct sk_buff *skb)
1843 {
1844 	struct dev_gso_cb *cb;
1845 
1846 	do {
1847 		struct sk_buff *nskb = skb->next;
1848 
1849 		skb->next = nskb->next;
1850 		nskb->next = NULL;
1851 		kfree_skb(nskb);
1852 	} while (skb->next);
1853 
1854 	cb = DEV_GSO_CB(skb);
1855 	if (cb->destructor)
1856 		cb->destructor(skb);
1857 }
1858 
1859 /**
1860  *	dev_gso_segment - Perform emulated hardware segmentation on skb.
1861  *	@skb: buffer to segment
1862  *
1863  *	This function segments the given skb and stores the list of segments
1864  *	in skb->next.
1865  */
1866 static int dev_gso_segment(struct sk_buff *skb)
1867 {
1868 	struct net_device *dev = skb->dev;
1869 	struct sk_buff *segs;
1870 	int features = dev->features & ~(illegal_highdma(dev, skb) ?
1871 					 NETIF_F_SG : 0);
1872 
1873 	segs = skb_gso_segment(skb, features);
1874 
1875 	/* Verifying header integrity only. */
1876 	if (!segs)
1877 		return 0;
1878 
1879 	if (IS_ERR(segs))
1880 		return PTR_ERR(segs);
1881 
1882 	skb->next = segs;
1883 	DEV_GSO_CB(skb)->destructor = skb->destructor;
1884 	skb->destructor = dev_gso_skb_destructor;
1885 
1886 	return 0;
1887 }
1888 
1889 /*
1890  * Try to orphan skb early, right before transmission by the device.
1891  * We cannot orphan skb if tx timestamp is requested, since
1892  * drivers need to call skb_tstamp_tx() to send the timestamp.
1893  */
1894 static inline void skb_orphan_try(struct sk_buff *skb)
1895 {
1896 	if (!skb_tx(skb)->flags)
1897 		skb_orphan(skb);
1898 }
1899 
1900 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
1901 			struct netdev_queue *txq)
1902 {
1903 	const struct net_device_ops *ops = dev->netdev_ops;
1904 	int rc = NETDEV_TX_OK;
1905 
1906 	if (likely(!skb->next)) {
1907 		if (!list_empty(&ptype_all))
1908 			dev_queue_xmit_nit(skb, dev);
1909 
1910 		/*
1911 		 * If device doesnt need skb->dst, release it right now while
1912 		 * its hot in this cpu cache
1913 		 */
1914 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
1915 			skb_dst_drop(skb);
1916 
1917 		skb_orphan_try(skb);
1918 
1919 		if (netif_needs_gso(dev, skb)) {
1920 			if (unlikely(dev_gso_segment(skb)))
1921 				goto out_kfree_skb;
1922 			if (skb->next)
1923 				goto gso;
1924 		}
1925 
1926 		rc = ops->ndo_start_xmit(skb, dev);
1927 		if (rc == NETDEV_TX_OK)
1928 			txq_trans_update(txq);
1929 		return rc;
1930 	}
1931 
1932 gso:
1933 	do {
1934 		struct sk_buff *nskb = skb->next;
1935 
1936 		skb->next = nskb->next;
1937 		nskb->next = NULL;
1938 
1939 		/*
1940 		 * If device doesnt need nskb->dst, release it right now while
1941 		 * its hot in this cpu cache
1942 		 */
1943 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
1944 			skb_dst_drop(nskb);
1945 
1946 		rc = ops->ndo_start_xmit(nskb, dev);
1947 		if (unlikely(rc != NETDEV_TX_OK)) {
1948 			if (rc & ~NETDEV_TX_MASK)
1949 				goto out_kfree_gso_skb;
1950 			nskb->next = skb->next;
1951 			skb->next = nskb;
1952 			return rc;
1953 		}
1954 		txq_trans_update(txq);
1955 		if (unlikely(netif_tx_queue_stopped(txq) && skb->next))
1956 			return NETDEV_TX_BUSY;
1957 	} while (skb->next);
1958 
1959 out_kfree_gso_skb:
1960 	if (likely(skb->next == NULL))
1961 		skb->destructor = DEV_GSO_CB(skb)->destructor;
1962 out_kfree_skb:
1963 	kfree_skb(skb);
1964 	return rc;
1965 }
1966 
1967 static u32 hashrnd __read_mostly;
1968 
1969 u16 skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb)
1970 {
1971 	u32 hash;
1972 
1973 	if (skb_rx_queue_recorded(skb)) {
1974 		hash = skb_get_rx_queue(skb);
1975 		while (unlikely(hash >= dev->real_num_tx_queues))
1976 			hash -= dev->real_num_tx_queues;
1977 		return hash;
1978 	}
1979 
1980 	if (skb->sk && skb->sk->sk_hash)
1981 		hash = skb->sk->sk_hash;
1982 	else
1983 		hash = (__force u16) skb->protocol;
1984 
1985 	hash = jhash_1word(hash, hashrnd);
1986 
1987 	return (u16) (((u64) hash * dev->real_num_tx_queues) >> 32);
1988 }
1989 EXPORT_SYMBOL(skb_tx_hash);
1990 
1991 static inline u16 dev_cap_txqueue(struct net_device *dev, u16 queue_index)
1992 {
1993 	if (unlikely(queue_index >= dev->real_num_tx_queues)) {
1994 		if (net_ratelimit()) {
1995 			pr_warning("%s selects TX queue %d, but "
1996 				"real number of TX queues is %d\n",
1997 				dev->name, queue_index, dev->real_num_tx_queues);
1998 		}
1999 		return 0;
2000 	}
2001 	return queue_index;
2002 }
2003 
2004 static struct netdev_queue *dev_pick_tx(struct net_device *dev,
2005 					struct sk_buff *skb)
2006 {
2007 	u16 queue_index;
2008 	struct sock *sk = skb->sk;
2009 
2010 	if (sk_tx_queue_recorded(sk)) {
2011 		queue_index = sk_tx_queue_get(sk);
2012 	} else {
2013 		const struct net_device_ops *ops = dev->netdev_ops;
2014 
2015 		if (ops->ndo_select_queue) {
2016 			queue_index = ops->ndo_select_queue(dev, skb);
2017 			queue_index = dev_cap_txqueue(dev, queue_index);
2018 		} else {
2019 			queue_index = 0;
2020 			if (dev->real_num_tx_queues > 1)
2021 				queue_index = skb_tx_hash(dev, skb);
2022 
2023 			if (sk) {
2024 				struct dst_entry *dst = rcu_dereference_check(sk->sk_dst_cache, 1);
2025 
2026 				if (dst && skb_dst(skb) == dst)
2027 					sk_tx_queue_set(sk, queue_index);
2028 			}
2029 		}
2030 	}
2031 
2032 	skb_set_queue_mapping(skb, queue_index);
2033 	return netdev_get_tx_queue(dev, queue_index);
2034 }
2035 
2036 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2037 				 struct net_device *dev,
2038 				 struct netdev_queue *txq)
2039 {
2040 	spinlock_t *root_lock = qdisc_lock(q);
2041 	int rc;
2042 
2043 	spin_lock(root_lock);
2044 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2045 		kfree_skb(skb);
2046 		rc = NET_XMIT_DROP;
2047 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2048 		   !test_and_set_bit(__QDISC_STATE_RUNNING, &q->state)) {
2049 		/*
2050 		 * This is a work-conserving queue; there are no old skbs
2051 		 * waiting to be sent out; and the qdisc is not running -
2052 		 * xmit the skb directly.
2053 		 */
2054 		if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2055 			skb_dst_force(skb);
2056 		__qdisc_update_bstats(q, skb->len);
2057 		if (sch_direct_xmit(skb, q, dev, txq, root_lock))
2058 			__qdisc_run(q);
2059 		else
2060 			clear_bit(__QDISC_STATE_RUNNING, &q->state);
2061 
2062 		rc = NET_XMIT_SUCCESS;
2063 	} else {
2064 		skb_dst_force(skb);
2065 		rc = qdisc_enqueue_root(skb, q);
2066 		qdisc_run(q);
2067 	}
2068 	spin_unlock(root_lock);
2069 
2070 	return rc;
2071 }
2072 
2073 /*
2074  * Returns true if either:
2075  *	1. skb has frag_list and the device doesn't support FRAGLIST, or
2076  *	2. skb is fragmented and the device does not support SG, or if
2077  *	   at least one of fragments is in highmem and device does not
2078  *	   support DMA from it.
2079  */
2080 static inline int skb_needs_linearize(struct sk_buff *skb,
2081 				      struct net_device *dev)
2082 {
2083 	return (skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
2084 	       (skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
2085 					      illegal_highdma(dev, skb)));
2086 }
2087 
2088 /**
2089  *	dev_queue_xmit - transmit a buffer
2090  *	@skb: buffer to transmit
2091  *
2092  *	Queue a buffer for transmission to a network device. The caller must
2093  *	have set the device and priority and built the buffer before calling
2094  *	this function. The function can be called from an interrupt.
2095  *
2096  *	A negative errno code is returned on a failure. A success does not
2097  *	guarantee the frame will be transmitted as it may be dropped due
2098  *	to congestion or traffic shaping.
2099  *
2100  * -----------------------------------------------------------------------------------
2101  *      I notice this method can also return errors from the queue disciplines,
2102  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
2103  *      be positive.
2104  *
2105  *      Regardless of the return value, the skb is consumed, so it is currently
2106  *      difficult to retry a send to this method.  (You can bump the ref count
2107  *      before sending to hold a reference for retry if you are careful.)
2108  *
2109  *      When calling this method, interrupts MUST be enabled.  This is because
2110  *      the BH enable code must have IRQs enabled so that it will not deadlock.
2111  *          --BLG
2112  */
2113 int dev_queue_xmit(struct sk_buff *skb)
2114 {
2115 	struct net_device *dev = skb->dev;
2116 	struct netdev_queue *txq;
2117 	struct Qdisc *q;
2118 	int rc = -ENOMEM;
2119 
2120 	/* GSO will handle the following emulations directly. */
2121 	if (netif_needs_gso(dev, skb))
2122 		goto gso;
2123 
2124 	/* Convert a paged skb to linear, if required */
2125 	if (skb_needs_linearize(skb, dev) && __skb_linearize(skb))
2126 		goto out_kfree_skb;
2127 
2128 	/* If packet is not checksummed and device does not support
2129 	 * checksumming for this protocol, complete checksumming here.
2130 	 */
2131 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
2132 		skb_set_transport_header(skb, skb->csum_start -
2133 					      skb_headroom(skb));
2134 		if (!dev_can_checksum(dev, skb) && skb_checksum_help(skb))
2135 			goto out_kfree_skb;
2136 	}
2137 
2138 gso:
2139 	/* Disable soft irqs for various locks below. Also
2140 	 * stops preemption for RCU.
2141 	 */
2142 	rcu_read_lock_bh();
2143 
2144 	txq = dev_pick_tx(dev, skb);
2145 	q = rcu_dereference_bh(txq->qdisc);
2146 
2147 #ifdef CONFIG_NET_CLS_ACT
2148 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2149 #endif
2150 	if (q->enqueue) {
2151 		rc = __dev_xmit_skb(skb, q, dev, txq);
2152 		goto out;
2153 	}
2154 
2155 	/* The device has no queue. Common case for software devices:
2156 	   loopback, all the sorts of tunnels...
2157 
2158 	   Really, it is unlikely that netif_tx_lock protection is necessary
2159 	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
2160 	   counters.)
2161 	   However, it is possible, that they rely on protection
2162 	   made by us here.
2163 
2164 	   Check this and shot the lock. It is not prone from deadlocks.
2165 	   Either shot noqueue qdisc, it is even simpler 8)
2166 	 */
2167 	if (dev->flags & IFF_UP) {
2168 		int cpu = smp_processor_id(); /* ok because BHs are off */
2169 
2170 		if (txq->xmit_lock_owner != cpu) {
2171 
2172 			HARD_TX_LOCK(dev, txq, cpu);
2173 
2174 			if (!netif_tx_queue_stopped(txq)) {
2175 				rc = dev_hard_start_xmit(skb, dev, txq);
2176 				if (dev_xmit_complete(rc)) {
2177 					HARD_TX_UNLOCK(dev, txq);
2178 					goto out;
2179 				}
2180 			}
2181 			HARD_TX_UNLOCK(dev, txq);
2182 			if (net_ratelimit())
2183 				printk(KERN_CRIT "Virtual device %s asks to "
2184 				       "queue packet!\n", dev->name);
2185 		} else {
2186 			/* Recursion is detected! It is possible,
2187 			 * unfortunately */
2188 			if (net_ratelimit())
2189 				printk(KERN_CRIT "Dead loop on virtual device "
2190 				       "%s, fix it urgently!\n", dev->name);
2191 		}
2192 	}
2193 
2194 	rc = -ENETDOWN;
2195 	rcu_read_unlock_bh();
2196 
2197 out_kfree_skb:
2198 	kfree_skb(skb);
2199 	return rc;
2200 out:
2201 	rcu_read_unlock_bh();
2202 	return rc;
2203 }
2204 EXPORT_SYMBOL(dev_queue_xmit);
2205 
2206 
2207 /*=======================================================================
2208 			Receiver routines
2209   =======================================================================*/
2210 
2211 int netdev_max_backlog __read_mostly = 1000;
2212 int netdev_tstamp_prequeue __read_mostly = 1;
2213 int netdev_budget __read_mostly = 300;
2214 int weight_p __read_mostly = 64;            /* old backlog weight */
2215 
2216 /* Called with irq disabled */
2217 static inline void ____napi_schedule(struct softnet_data *sd,
2218 				     struct napi_struct *napi)
2219 {
2220 	list_add_tail(&napi->poll_list, &sd->poll_list);
2221 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2222 }
2223 
2224 #ifdef CONFIG_RPS
2225 
2226 /* One global table that all flow-based protocols share. */
2227 struct rps_sock_flow_table *rps_sock_flow_table __read_mostly;
2228 EXPORT_SYMBOL(rps_sock_flow_table);
2229 
2230 /*
2231  * get_rps_cpu is called from netif_receive_skb and returns the target
2232  * CPU from the RPS map of the receiving queue for a given skb.
2233  * rcu_read_lock must be held on entry.
2234  */
2235 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2236 		       struct rps_dev_flow **rflowp)
2237 {
2238 	struct ipv6hdr *ip6;
2239 	struct iphdr *ip;
2240 	struct netdev_rx_queue *rxqueue;
2241 	struct rps_map *map;
2242 	struct rps_dev_flow_table *flow_table;
2243 	struct rps_sock_flow_table *sock_flow_table;
2244 	int cpu = -1;
2245 	u8 ip_proto;
2246 	u16 tcpu;
2247 	u32 addr1, addr2, ihl;
2248 	union {
2249 		u32 v32;
2250 		u16 v16[2];
2251 	} ports;
2252 
2253 	if (skb_rx_queue_recorded(skb)) {
2254 		u16 index = skb_get_rx_queue(skb);
2255 		if (unlikely(index >= dev->num_rx_queues)) {
2256 			WARN_ONCE(dev->num_rx_queues > 1, "%s received packet "
2257 				"on queue %u, but number of RX queues is %u\n",
2258 				dev->name, index, dev->num_rx_queues);
2259 			goto done;
2260 		}
2261 		rxqueue = dev->_rx + index;
2262 	} else
2263 		rxqueue = dev->_rx;
2264 
2265 	if (!rxqueue->rps_map && !rxqueue->rps_flow_table)
2266 		goto done;
2267 
2268 	if (skb->rxhash)
2269 		goto got_hash; /* Skip hash computation on packet header */
2270 
2271 	switch (skb->protocol) {
2272 	case __constant_htons(ETH_P_IP):
2273 		if (!pskb_may_pull(skb, sizeof(*ip)))
2274 			goto done;
2275 
2276 		ip = (struct iphdr *) skb->data;
2277 		ip_proto = ip->protocol;
2278 		addr1 = (__force u32) ip->saddr;
2279 		addr2 = (__force u32) ip->daddr;
2280 		ihl = ip->ihl;
2281 		break;
2282 	case __constant_htons(ETH_P_IPV6):
2283 		if (!pskb_may_pull(skb, sizeof(*ip6)))
2284 			goto done;
2285 
2286 		ip6 = (struct ipv6hdr *) skb->data;
2287 		ip_proto = ip6->nexthdr;
2288 		addr1 = (__force u32) ip6->saddr.s6_addr32[3];
2289 		addr2 = (__force u32) ip6->daddr.s6_addr32[3];
2290 		ihl = (40 >> 2);
2291 		break;
2292 	default:
2293 		goto done;
2294 	}
2295 	switch (ip_proto) {
2296 	case IPPROTO_TCP:
2297 	case IPPROTO_UDP:
2298 	case IPPROTO_DCCP:
2299 	case IPPROTO_ESP:
2300 	case IPPROTO_AH:
2301 	case IPPROTO_SCTP:
2302 	case IPPROTO_UDPLITE:
2303 		if (pskb_may_pull(skb, (ihl * 4) + 4)) {
2304 			ports.v32 = * (__force u32 *) (skb->data + (ihl * 4));
2305 			if (ports.v16[1] < ports.v16[0])
2306 				swap(ports.v16[0], ports.v16[1]);
2307 			break;
2308 		}
2309 	default:
2310 		ports.v32 = 0;
2311 		break;
2312 	}
2313 
2314 	/* get a consistent hash (same value on both flow directions) */
2315 	if (addr2 < addr1)
2316 		swap(addr1, addr2);
2317 	skb->rxhash = jhash_3words(addr1, addr2, ports.v32, hashrnd);
2318 	if (!skb->rxhash)
2319 		skb->rxhash = 1;
2320 
2321 got_hash:
2322 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
2323 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
2324 	if (flow_table && sock_flow_table) {
2325 		u16 next_cpu;
2326 		struct rps_dev_flow *rflow;
2327 
2328 		rflow = &flow_table->flows[skb->rxhash & flow_table->mask];
2329 		tcpu = rflow->cpu;
2330 
2331 		next_cpu = sock_flow_table->ents[skb->rxhash &
2332 		    sock_flow_table->mask];
2333 
2334 		/*
2335 		 * If the desired CPU (where last recvmsg was done) is
2336 		 * different from current CPU (one in the rx-queue flow
2337 		 * table entry), switch if one of the following holds:
2338 		 *   - Current CPU is unset (equal to RPS_NO_CPU).
2339 		 *   - Current CPU is offline.
2340 		 *   - The current CPU's queue tail has advanced beyond the
2341 		 *     last packet that was enqueued using this table entry.
2342 		 *     This guarantees that all previous packets for the flow
2343 		 *     have been dequeued, thus preserving in order delivery.
2344 		 */
2345 		if (unlikely(tcpu != next_cpu) &&
2346 		    (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
2347 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
2348 		      rflow->last_qtail)) >= 0)) {
2349 			tcpu = rflow->cpu = next_cpu;
2350 			if (tcpu != RPS_NO_CPU)
2351 				rflow->last_qtail = per_cpu(softnet_data,
2352 				    tcpu).input_queue_head;
2353 		}
2354 		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
2355 			*rflowp = rflow;
2356 			cpu = tcpu;
2357 			goto done;
2358 		}
2359 	}
2360 
2361 	map = rcu_dereference(rxqueue->rps_map);
2362 	if (map) {
2363 		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
2364 
2365 		if (cpu_online(tcpu)) {
2366 			cpu = tcpu;
2367 			goto done;
2368 		}
2369 	}
2370 
2371 done:
2372 	return cpu;
2373 }
2374 
2375 /* Called from hardirq (IPI) context */
2376 static void rps_trigger_softirq(void *data)
2377 {
2378 	struct softnet_data *sd = data;
2379 
2380 	____napi_schedule(sd, &sd->backlog);
2381 	sd->received_rps++;
2382 }
2383 
2384 #endif /* CONFIG_RPS */
2385 
2386 /*
2387  * Check if this softnet_data structure is another cpu one
2388  * If yes, queue it to our IPI list and return 1
2389  * If no, return 0
2390  */
2391 static int rps_ipi_queued(struct softnet_data *sd)
2392 {
2393 #ifdef CONFIG_RPS
2394 	struct softnet_data *mysd = &__get_cpu_var(softnet_data);
2395 
2396 	if (sd != mysd) {
2397 		sd->rps_ipi_next = mysd->rps_ipi_list;
2398 		mysd->rps_ipi_list = sd;
2399 
2400 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2401 		return 1;
2402 	}
2403 #endif /* CONFIG_RPS */
2404 	return 0;
2405 }
2406 
2407 /*
2408  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
2409  * queue (may be a remote CPU queue).
2410  */
2411 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
2412 			      unsigned int *qtail)
2413 {
2414 	struct softnet_data *sd;
2415 	unsigned long flags;
2416 
2417 	sd = &per_cpu(softnet_data, cpu);
2418 
2419 	local_irq_save(flags);
2420 
2421 	rps_lock(sd);
2422 	if (skb_queue_len(&sd->input_pkt_queue) <= netdev_max_backlog) {
2423 		if (skb_queue_len(&sd->input_pkt_queue)) {
2424 enqueue:
2425 			__skb_queue_tail(&sd->input_pkt_queue, skb);
2426 			input_queue_tail_incr_save(sd, qtail);
2427 			rps_unlock(sd);
2428 			local_irq_restore(flags);
2429 			return NET_RX_SUCCESS;
2430 		}
2431 
2432 		/* Schedule NAPI for backlog device
2433 		 * We can use non atomic operation since we own the queue lock
2434 		 */
2435 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
2436 			if (!rps_ipi_queued(sd))
2437 				____napi_schedule(sd, &sd->backlog);
2438 		}
2439 		goto enqueue;
2440 	}
2441 
2442 	sd->dropped++;
2443 	rps_unlock(sd);
2444 
2445 	local_irq_restore(flags);
2446 
2447 	kfree_skb(skb);
2448 	return NET_RX_DROP;
2449 }
2450 
2451 /**
2452  *	netif_rx	-	post buffer to the network code
2453  *	@skb: buffer to post
2454  *
2455  *	This function receives a packet from a device driver and queues it for
2456  *	the upper (protocol) levels to process.  It always succeeds. The buffer
2457  *	may be dropped during processing for congestion control or by the
2458  *	protocol layers.
2459  *
2460  *	return values:
2461  *	NET_RX_SUCCESS	(no congestion)
2462  *	NET_RX_DROP     (packet was dropped)
2463  *
2464  */
2465 
2466 int netif_rx(struct sk_buff *skb)
2467 {
2468 	int ret;
2469 
2470 	/* if netpoll wants it, pretend we never saw it */
2471 	if (netpoll_rx(skb))
2472 		return NET_RX_DROP;
2473 
2474 	if (netdev_tstamp_prequeue)
2475 		net_timestamp_check(skb);
2476 
2477 #ifdef CONFIG_RPS
2478 	{
2479 		struct rps_dev_flow voidflow, *rflow = &voidflow;
2480 		int cpu;
2481 
2482 		rcu_read_lock();
2483 
2484 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
2485 		if (cpu < 0)
2486 			cpu = smp_processor_id();
2487 
2488 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
2489 
2490 		rcu_read_unlock();
2491 	}
2492 #else
2493 	{
2494 		unsigned int qtail;
2495 		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
2496 		put_cpu();
2497 	}
2498 #endif
2499 	return ret;
2500 }
2501 EXPORT_SYMBOL(netif_rx);
2502 
2503 int netif_rx_ni(struct sk_buff *skb)
2504 {
2505 	int err;
2506 
2507 	preempt_disable();
2508 	err = netif_rx(skb);
2509 	if (local_softirq_pending())
2510 		do_softirq();
2511 	preempt_enable();
2512 
2513 	return err;
2514 }
2515 EXPORT_SYMBOL(netif_rx_ni);
2516 
2517 static void net_tx_action(struct softirq_action *h)
2518 {
2519 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
2520 
2521 	if (sd->completion_queue) {
2522 		struct sk_buff *clist;
2523 
2524 		local_irq_disable();
2525 		clist = sd->completion_queue;
2526 		sd->completion_queue = NULL;
2527 		local_irq_enable();
2528 
2529 		while (clist) {
2530 			struct sk_buff *skb = clist;
2531 			clist = clist->next;
2532 
2533 			WARN_ON(atomic_read(&skb->users));
2534 			__kfree_skb(skb);
2535 		}
2536 	}
2537 
2538 	if (sd->output_queue) {
2539 		struct Qdisc *head;
2540 
2541 		local_irq_disable();
2542 		head = sd->output_queue;
2543 		sd->output_queue = NULL;
2544 		sd->output_queue_tailp = &sd->output_queue;
2545 		local_irq_enable();
2546 
2547 		while (head) {
2548 			struct Qdisc *q = head;
2549 			spinlock_t *root_lock;
2550 
2551 			head = head->next_sched;
2552 
2553 			root_lock = qdisc_lock(q);
2554 			if (spin_trylock(root_lock)) {
2555 				smp_mb__before_clear_bit();
2556 				clear_bit(__QDISC_STATE_SCHED,
2557 					  &q->state);
2558 				qdisc_run(q);
2559 				spin_unlock(root_lock);
2560 			} else {
2561 				if (!test_bit(__QDISC_STATE_DEACTIVATED,
2562 					      &q->state)) {
2563 					__netif_reschedule(q);
2564 				} else {
2565 					smp_mb__before_clear_bit();
2566 					clear_bit(__QDISC_STATE_SCHED,
2567 						  &q->state);
2568 				}
2569 			}
2570 		}
2571 	}
2572 }
2573 
2574 static inline int deliver_skb(struct sk_buff *skb,
2575 			      struct packet_type *pt_prev,
2576 			      struct net_device *orig_dev)
2577 {
2578 	atomic_inc(&skb->users);
2579 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2580 }
2581 
2582 #if defined(CONFIG_BRIDGE) || defined (CONFIG_BRIDGE_MODULE)
2583 
2584 #if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
2585 /* This hook is defined here for ATM LANE */
2586 int (*br_fdb_test_addr_hook)(struct net_device *dev,
2587 			     unsigned char *addr) __read_mostly;
2588 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
2589 #endif
2590 
2591 /*
2592  * If bridge module is loaded call bridging hook.
2593  *  returns NULL if packet was consumed.
2594  */
2595 struct sk_buff *(*br_handle_frame_hook)(struct net_bridge_port *p,
2596 					struct sk_buff *skb) __read_mostly;
2597 EXPORT_SYMBOL_GPL(br_handle_frame_hook);
2598 
2599 static inline struct sk_buff *handle_bridge(struct sk_buff *skb,
2600 					    struct packet_type **pt_prev, int *ret,
2601 					    struct net_device *orig_dev)
2602 {
2603 	struct net_bridge_port *port;
2604 
2605 	if (skb->pkt_type == PACKET_LOOPBACK ||
2606 	    (port = rcu_dereference(skb->dev->br_port)) == NULL)
2607 		return skb;
2608 
2609 	if (*pt_prev) {
2610 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
2611 		*pt_prev = NULL;
2612 	}
2613 
2614 	return br_handle_frame_hook(port, skb);
2615 }
2616 #else
2617 #define handle_bridge(skb, pt_prev, ret, orig_dev)	(skb)
2618 #endif
2619 
2620 #if defined(CONFIG_MACVLAN) || defined(CONFIG_MACVLAN_MODULE)
2621 struct sk_buff *(*macvlan_handle_frame_hook)(struct macvlan_port *p,
2622 					     struct sk_buff *skb) __read_mostly;
2623 EXPORT_SYMBOL_GPL(macvlan_handle_frame_hook);
2624 
2625 static inline struct sk_buff *handle_macvlan(struct sk_buff *skb,
2626 					     struct packet_type **pt_prev,
2627 					     int *ret,
2628 					     struct net_device *orig_dev)
2629 {
2630 	struct macvlan_port *port;
2631 
2632 	port = rcu_dereference(skb->dev->macvlan_port);
2633 	if (!port)
2634 		return skb;
2635 
2636 	if (*pt_prev) {
2637 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
2638 		*pt_prev = NULL;
2639 	}
2640 	return macvlan_handle_frame_hook(port, skb);
2641 }
2642 #else
2643 #define handle_macvlan(skb, pt_prev, ret, orig_dev)	(skb)
2644 #endif
2645 
2646 #ifdef CONFIG_NET_CLS_ACT
2647 /* TODO: Maybe we should just force sch_ingress to be compiled in
2648  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
2649  * a compare and 2 stores extra right now if we dont have it on
2650  * but have CONFIG_NET_CLS_ACT
2651  * NOTE: This doesnt stop any functionality; if you dont have
2652  * the ingress scheduler, you just cant add policies on ingress.
2653  *
2654  */
2655 static int ing_filter(struct sk_buff *skb)
2656 {
2657 	struct net_device *dev = skb->dev;
2658 	u32 ttl = G_TC_RTTL(skb->tc_verd);
2659 	struct netdev_queue *rxq;
2660 	int result = TC_ACT_OK;
2661 	struct Qdisc *q;
2662 
2663 	if (MAX_RED_LOOP < ttl++) {
2664 		printk(KERN_WARNING
2665 		       "Redir loop detected Dropping packet (%d->%d)\n",
2666 		       skb->skb_iif, dev->ifindex);
2667 		return TC_ACT_SHOT;
2668 	}
2669 
2670 	skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
2671 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
2672 
2673 	rxq = &dev->rx_queue;
2674 
2675 	q = rxq->qdisc;
2676 	if (q != &noop_qdisc) {
2677 		spin_lock(qdisc_lock(q));
2678 		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
2679 			result = qdisc_enqueue_root(skb, q);
2680 		spin_unlock(qdisc_lock(q));
2681 	}
2682 
2683 	return result;
2684 }
2685 
2686 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
2687 					 struct packet_type **pt_prev,
2688 					 int *ret, struct net_device *orig_dev)
2689 {
2690 	if (skb->dev->rx_queue.qdisc == &noop_qdisc)
2691 		goto out;
2692 
2693 	if (*pt_prev) {
2694 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
2695 		*pt_prev = NULL;
2696 	} else {
2697 		/* Huh? Why does turning on AF_PACKET affect this? */
2698 		skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
2699 	}
2700 
2701 	switch (ing_filter(skb)) {
2702 	case TC_ACT_SHOT:
2703 	case TC_ACT_STOLEN:
2704 		kfree_skb(skb);
2705 		return NULL;
2706 	}
2707 
2708 out:
2709 	skb->tc_verd = 0;
2710 	return skb;
2711 }
2712 #endif
2713 
2714 /*
2715  * 	netif_nit_deliver - deliver received packets to network taps
2716  * 	@skb: buffer
2717  *
2718  * 	This function is used to deliver incoming packets to network
2719  * 	taps. It should be used when the normal netif_receive_skb path
2720  * 	is bypassed, for example because of VLAN acceleration.
2721  */
2722 void netif_nit_deliver(struct sk_buff *skb)
2723 {
2724 	struct packet_type *ptype;
2725 
2726 	if (list_empty(&ptype_all))
2727 		return;
2728 
2729 	skb_reset_network_header(skb);
2730 	skb_reset_transport_header(skb);
2731 	skb->mac_len = skb->network_header - skb->mac_header;
2732 
2733 	rcu_read_lock();
2734 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
2735 		if (!ptype->dev || ptype->dev == skb->dev)
2736 			deliver_skb(skb, ptype, skb->dev);
2737 	}
2738 	rcu_read_unlock();
2739 }
2740 
2741 static inline void skb_bond_set_mac_by_master(struct sk_buff *skb,
2742 					      struct net_device *master)
2743 {
2744 	if (skb->pkt_type == PACKET_HOST) {
2745 		u16 *dest = (u16 *) eth_hdr(skb)->h_dest;
2746 
2747 		memcpy(dest, master->dev_addr, ETH_ALEN);
2748 	}
2749 }
2750 
2751 /* On bonding slaves other than the currently active slave, suppress
2752  * duplicates except for 802.3ad ETH_P_SLOW, alb non-mcast/bcast, and
2753  * ARP on active-backup slaves with arp_validate enabled.
2754  */
2755 int __skb_bond_should_drop(struct sk_buff *skb, struct net_device *master)
2756 {
2757 	struct net_device *dev = skb->dev;
2758 
2759 	if (master->priv_flags & IFF_MASTER_ARPMON)
2760 		dev->last_rx = jiffies;
2761 
2762 	if ((master->priv_flags & IFF_MASTER_ALB) && master->br_port) {
2763 		/* Do address unmangle. The local destination address
2764 		 * will be always the one master has. Provides the right
2765 		 * functionality in a bridge.
2766 		 */
2767 		skb_bond_set_mac_by_master(skb, master);
2768 	}
2769 
2770 	if (dev->priv_flags & IFF_SLAVE_INACTIVE) {
2771 		if ((dev->priv_flags & IFF_SLAVE_NEEDARP) &&
2772 		    skb->protocol == __cpu_to_be16(ETH_P_ARP))
2773 			return 0;
2774 
2775 		if (master->priv_flags & IFF_MASTER_ALB) {
2776 			if (skb->pkt_type != PACKET_BROADCAST &&
2777 			    skb->pkt_type != PACKET_MULTICAST)
2778 				return 0;
2779 		}
2780 		if (master->priv_flags & IFF_MASTER_8023AD &&
2781 		    skb->protocol == __cpu_to_be16(ETH_P_SLOW))
2782 			return 0;
2783 
2784 		return 1;
2785 	}
2786 	return 0;
2787 }
2788 EXPORT_SYMBOL(__skb_bond_should_drop);
2789 
2790 static int __netif_receive_skb(struct sk_buff *skb)
2791 {
2792 	struct packet_type *ptype, *pt_prev;
2793 	struct net_device *orig_dev;
2794 	struct net_device *master;
2795 	struct net_device *null_or_orig;
2796 	struct net_device *orig_or_bond;
2797 	int ret = NET_RX_DROP;
2798 	__be16 type;
2799 
2800 	if (!netdev_tstamp_prequeue)
2801 		net_timestamp_check(skb);
2802 
2803 	if (vlan_tx_tag_present(skb) && vlan_hwaccel_do_receive(skb))
2804 		return NET_RX_SUCCESS;
2805 
2806 	/* if we've gotten here through NAPI, check netpoll */
2807 	if (netpoll_receive_skb(skb))
2808 		return NET_RX_DROP;
2809 
2810 	if (!skb->skb_iif)
2811 		skb->skb_iif = skb->dev->ifindex;
2812 
2813 	/*
2814 	 * bonding note: skbs received on inactive slaves should only
2815 	 * be delivered to pkt handlers that are exact matches.  Also
2816 	 * the deliver_no_wcard flag will be set.  If packet handlers
2817 	 * are sensitive to duplicate packets these skbs will need to
2818 	 * be dropped at the handler.  The vlan accel path may have
2819 	 * already set the deliver_no_wcard flag.
2820 	 */
2821 	null_or_orig = NULL;
2822 	orig_dev = skb->dev;
2823 	master = ACCESS_ONCE(orig_dev->master);
2824 	if (skb->deliver_no_wcard)
2825 		null_or_orig = orig_dev;
2826 	else if (master) {
2827 		if (skb_bond_should_drop(skb, master)) {
2828 			skb->deliver_no_wcard = 1;
2829 			null_or_orig = orig_dev; /* deliver only exact match */
2830 		} else
2831 			skb->dev = master;
2832 	}
2833 
2834 	__get_cpu_var(softnet_data).processed++;
2835 
2836 	skb_reset_network_header(skb);
2837 	skb_reset_transport_header(skb);
2838 	skb->mac_len = skb->network_header - skb->mac_header;
2839 
2840 	pt_prev = NULL;
2841 
2842 	rcu_read_lock();
2843 
2844 #ifdef CONFIG_NET_CLS_ACT
2845 	if (skb->tc_verd & TC_NCLS) {
2846 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
2847 		goto ncls;
2848 	}
2849 #endif
2850 
2851 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
2852 		if (ptype->dev == null_or_orig || ptype->dev == skb->dev ||
2853 		    ptype->dev == orig_dev) {
2854 			if (pt_prev)
2855 				ret = deliver_skb(skb, pt_prev, orig_dev);
2856 			pt_prev = ptype;
2857 		}
2858 	}
2859 
2860 #ifdef CONFIG_NET_CLS_ACT
2861 	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
2862 	if (!skb)
2863 		goto out;
2864 ncls:
2865 #endif
2866 
2867 	skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
2868 	if (!skb)
2869 		goto out;
2870 	skb = handle_macvlan(skb, &pt_prev, &ret, orig_dev);
2871 	if (!skb)
2872 		goto out;
2873 
2874 	/*
2875 	 * Make sure frames received on VLAN interfaces stacked on
2876 	 * bonding interfaces still make their way to any base bonding
2877 	 * device that may have registered for a specific ptype.  The
2878 	 * handler may have to adjust skb->dev and orig_dev.
2879 	 */
2880 	orig_or_bond = orig_dev;
2881 	if ((skb->dev->priv_flags & IFF_802_1Q_VLAN) &&
2882 	    (vlan_dev_real_dev(skb->dev)->priv_flags & IFF_BONDING)) {
2883 		orig_or_bond = vlan_dev_real_dev(skb->dev);
2884 	}
2885 
2886 	type = skb->protocol;
2887 	list_for_each_entry_rcu(ptype,
2888 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
2889 		if (ptype->type == type && (ptype->dev == null_or_orig ||
2890 		     ptype->dev == skb->dev || ptype->dev == orig_dev ||
2891 		     ptype->dev == orig_or_bond)) {
2892 			if (pt_prev)
2893 				ret = deliver_skb(skb, pt_prev, orig_dev);
2894 			pt_prev = ptype;
2895 		}
2896 	}
2897 
2898 	if (pt_prev) {
2899 		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2900 	} else {
2901 		kfree_skb(skb);
2902 		/* Jamal, now you will not able to escape explaining
2903 		 * me how you were going to use this. :-)
2904 		 */
2905 		ret = NET_RX_DROP;
2906 	}
2907 
2908 out:
2909 	rcu_read_unlock();
2910 	return ret;
2911 }
2912 
2913 /**
2914  *	netif_receive_skb - process receive buffer from network
2915  *	@skb: buffer to process
2916  *
2917  *	netif_receive_skb() is the main receive data processing function.
2918  *	It always succeeds. The buffer may be dropped during processing
2919  *	for congestion control or by the protocol layers.
2920  *
2921  *	This function may only be called from softirq context and interrupts
2922  *	should be enabled.
2923  *
2924  *	Return values (usually ignored):
2925  *	NET_RX_SUCCESS: no congestion
2926  *	NET_RX_DROP: packet was dropped
2927  */
2928 int netif_receive_skb(struct sk_buff *skb)
2929 {
2930 	if (netdev_tstamp_prequeue)
2931 		net_timestamp_check(skb);
2932 
2933 #ifdef CONFIG_RPS
2934 	{
2935 		struct rps_dev_flow voidflow, *rflow = &voidflow;
2936 		int cpu, ret;
2937 
2938 		rcu_read_lock();
2939 
2940 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
2941 
2942 		if (cpu >= 0) {
2943 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
2944 			rcu_read_unlock();
2945 		} else {
2946 			rcu_read_unlock();
2947 			ret = __netif_receive_skb(skb);
2948 		}
2949 
2950 		return ret;
2951 	}
2952 #else
2953 	return __netif_receive_skb(skb);
2954 #endif
2955 }
2956 EXPORT_SYMBOL(netif_receive_skb);
2957 
2958 /* Network device is going away, flush any packets still pending
2959  * Called with irqs disabled.
2960  */
2961 static void flush_backlog(void *arg)
2962 {
2963 	struct net_device *dev = arg;
2964 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
2965 	struct sk_buff *skb, *tmp;
2966 
2967 	rps_lock(sd);
2968 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
2969 		if (skb->dev == dev) {
2970 			__skb_unlink(skb, &sd->input_pkt_queue);
2971 			kfree_skb(skb);
2972 			input_queue_head_incr(sd);
2973 		}
2974 	}
2975 	rps_unlock(sd);
2976 
2977 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
2978 		if (skb->dev == dev) {
2979 			__skb_unlink(skb, &sd->process_queue);
2980 			kfree_skb(skb);
2981 			input_queue_head_incr(sd);
2982 		}
2983 	}
2984 }
2985 
2986 static int napi_gro_complete(struct sk_buff *skb)
2987 {
2988 	struct packet_type *ptype;
2989 	__be16 type = skb->protocol;
2990 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
2991 	int err = -ENOENT;
2992 
2993 	if (NAPI_GRO_CB(skb)->count == 1) {
2994 		skb_shinfo(skb)->gso_size = 0;
2995 		goto out;
2996 	}
2997 
2998 	rcu_read_lock();
2999 	list_for_each_entry_rcu(ptype, head, list) {
3000 		if (ptype->type != type || ptype->dev || !ptype->gro_complete)
3001 			continue;
3002 
3003 		err = ptype->gro_complete(skb);
3004 		break;
3005 	}
3006 	rcu_read_unlock();
3007 
3008 	if (err) {
3009 		WARN_ON(&ptype->list == head);
3010 		kfree_skb(skb);
3011 		return NET_RX_SUCCESS;
3012 	}
3013 
3014 out:
3015 	return netif_receive_skb(skb);
3016 }
3017 
3018 static void napi_gro_flush(struct napi_struct *napi)
3019 {
3020 	struct sk_buff *skb, *next;
3021 
3022 	for (skb = napi->gro_list; skb; skb = next) {
3023 		next = skb->next;
3024 		skb->next = NULL;
3025 		napi_gro_complete(skb);
3026 	}
3027 
3028 	napi->gro_count = 0;
3029 	napi->gro_list = NULL;
3030 }
3031 
3032 enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3033 {
3034 	struct sk_buff **pp = NULL;
3035 	struct packet_type *ptype;
3036 	__be16 type = skb->protocol;
3037 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
3038 	int same_flow;
3039 	int mac_len;
3040 	enum gro_result ret;
3041 
3042 	if (!(skb->dev->features & NETIF_F_GRO))
3043 		goto normal;
3044 
3045 	if (skb_is_gso(skb) || skb_has_frags(skb))
3046 		goto normal;
3047 
3048 	rcu_read_lock();
3049 	list_for_each_entry_rcu(ptype, head, list) {
3050 		if (ptype->type != type || ptype->dev || !ptype->gro_receive)
3051 			continue;
3052 
3053 		skb_set_network_header(skb, skb_gro_offset(skb));
3054 		mac_len = skb->network_header - skb->mac_header;
3055 		skb->mac_len = mac_len;
3056 		NAPI_GRO_CB(skb)->same_flow = 0;
3057 		NAPI_GRO_CB(skb)->flush = 0;
3058 		NAPI_GRO_CB(skb)->free = 0;
3059 
3060 		pp = ptype->gro_receive(&napi->gro_list, skb);
3061 		break;
3062 	}
3063 	rcu_read_unlock();
3064 
3065 	if (&ptype->list == head)
3066 		goto normal;
3067 
3068 	same_flow = NAPI_GRO_CB(skb)->same_flow;
3069 	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3070 
3071 	if (pp) {
3072 		struct sk_buff *nskb = *pp;
3073 
3074 		*pp = nskb->next;
3075 		nskb->next = NULL;
3076 		napi_gro_complete(nskb);
3077 		napi->gro_count--;
3078 	}
3079 
3080 	if (same_flow)
3081 		goto ok;
3082 
3083 	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3084 		goto normal;
3085 
3086 	napi->gro_count++;
3087 	NAPI_GRO_CB(skb)->count = 1;
3088 	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3089 	skb->next = napi->gro_list;
3090 	napi->gro_list = skb;
3091 	ret = GRO_HELD;
3092 
3093 pull:
3094 	if (skb_headlen(skb) < skb_gro_offset(skb)) {
3095 		int grow = skb_gro_offset(skb) - skb_headlen(skb);
3096 
3097 		BUG_ON(skb->end - skb->tail < grow);
3098 
3099 		memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3100 
3101 		skb->tail += grow;
3102 		skb->data_len -= grow;
3103 
3104 		skb_shinfo(skb)->frags[0].page_offset += grow;
3105 		skb_shinfo(skb)->frags[0].size -= grow;
3106 
3107 		if (unlikely(!skb_shinfo(skb)->frags[0].size)) {
3108 			put_page(skb_shinfo(skb)->frags[0].page);
3109 			memmove(skb_shinfo(skb)->frags,
3110 				skb_shinfo(skb)->frags + 1,
3111 				--skb_shinfo(skb)->nr_frags);
3112 		}
3113 	}
3114 
3115 ok:
3116 	return ret;
3117 
3118 normal:
3119 	ret = GRO_NORMAL;
3120 	goto pull;
3121 }
3122 EXPORT_SYMBOL(dev_gro_receive);
3123 
3124 static gro_result_t
3125 __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3126 {
3127 	struct sk_buff *p;
3128 
3129 	if (netpoll_rx_on(skb))
3130 		return GRO_NORMAL;
3131 
3132 	for (p = napi->gro_list; p; p = p->next) {
3133 		NAPI_GRO_CB(p)->same_flow =
3134 			(p->dev == skb->dev) &&
3135 			!compare_ether_header(skb_mac_header(p),
3136 					      skb_gro_mac_header(skb));
3137 		NAPI_GRO_CB(p)->flush = 0;
3138 	}
3139 
3140 	return dev_gro_receive(napi, skb);
3141 }
3142 
3143 gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
3144 {
3145 	switch (ret) {
3146 	case GRO_NORMAL:
3147 		if (netif_receive_skb(skb))
3148 			ret = GRO_DROP;
3149 		break;
3150 
3151 	case GRO_DROP:
3152 	case GRO_MERGED_FREE:
3153 		kfree_skb(skb);
3154 		break;
3155 
3156 	case GRO_HELD:
3157 	case GRO_MERGED:
3158 		break;
3159 	}
3160 
3161 	return ret;
3162 }
3163 EXPORT_SYMBOL(napi_skb_finish);
3164 
3165 void skb_gro_reset_offset(struct sk_buff *skb)
3166 {
3167 	NAPI_GRO_CB(skb)->data_offset = 0;
3168 	NAPI_GRO_CB(skb)->frag0 = NULL;
3169 	NAPI_GRO_CB(skb)->frag0_len = 0;
3170 
3171 	if (skb->mac_header == skb->tail &&
3172 	    !PageHighMem(skb_shinfo(skb)->frags[0].page)) {
3173 		NAPI_GRO_CB(skb)->frag0 =
3174 			page_address(skb_shinfo(skb)->frags[0].page) +
3175 			skb_shinfo(skb)->frags[0].page_offset;
3176 		NAPI_GRO_CB(skb)->frag0_len = skb_shinfo(skb)->frags[0].size;
3177 	}
3178 }
3179 EXPORT_SYMBOL(skb_gro_reset_offset);
3180 
3181 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3182 {
3183 	skb_gro_reset_offset(skb);
3184 
3185 	return napi_skb_finish(__napi_gro_receive(napi, skb), skb);
3186 }
3187 EXPORT_SYMBOL(napi_gro_receive);
3188 
3189 void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3190 {
3191 	__skb_pull(skb, skb_headlen(skb));
3192 	skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb));
3193 
3194 	napi->skb = skb;
3195 }
3196 EXPORT_SYMBOL(napi_reuse_skb);
3197 
3198 struct sk_buff *napi_get_frags(struct napi_struct *napi)
3199 {
3200 	struct sk_buff *skb = napi->skb;
3201 
3202 	if (!skb) {
3203 		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
3204 		if (skb)
3205 			napi->skb = skb;
3206 	}
3207 	return skb;
3208 }
3209 EXPORT_SYMBOL(napi_get_frags);
3210 
3211 gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3212 			       gro_result_t ret)
3213 {
3214 	switch (ret) {
3215 	case GRO_NORMAL:
3216 	case GRO_HELD:
3217 		skb->protocol = eth_type_trans(skb, skb->dev);
3218 
3219 		if (ret == GRO_HELD)
3220 			skb_gro_pull(skb, -ETH_HLEN);
3221 		else if (netif_receive_skb(skb))
3222 			ret = GRO_DROP;
3223 		break;
3224 
3225 	case GRO_DROP:
3226 	case GRO_MERGED_FREE:
3227 		napi_reuse_skb(napi, skb);
3228 		break;
3229 
3230 	case GRO_MERGED:
3231 		break;
3232 	}
3233 
3234 	return ret;
3235 }
3236 EXPORT_SYMBOL(napi_frags_finish);
3237 
3238 struct sk_buff *napi_frags_skb(struct napi_struct *napi)
3239 {
3240 	struct sk_buff *skb = napi->skb;
3241 	struct ethhdr *eth;
3242 	unsigned int hlen;
3243 	unsigned int off;
3244 
3245 	napi->skb = NULL;
3246 
3247 	skb_reset_mac_header(skb);
3248 	skb_gro_reset_offset(skb);
3249 
3250 	off = skb_gro_offset(skb);
3251 	hlen = off + sizeof(*eth);
3252 	eth = skb_gro_header_fast(skb, off);
3253 	if (skb_gro_header_hard(skb, hlen)) {
3254 		eth = skb_gro_header_slow(skb, hlen, off);
3255 		if (unlikely(!eth)) {
3256 			napi_reuse_skb(napi, skb);
3257 			skb = NULL;
3258 			goto out;
3259 		}
3260 	}
3261 
3262 	skb_gro_pull(skb, sizeof(*eth));
3263 
3264 	/*
3265 	 * This works because the only protocols we care about don't require
3266 	 * special handling.  We'll fix it up properly at the end.
3267 	 */
3268 	skb->protocol = eth->h_proto;
3269 
3270 out:
3271 	return skb;
3272 }
3273 EXPORT_SYMBOL(napi_frags_skb);
3274 
3275 gro_result_t napi_gro_frags(struct napi_struct *napi)
3276 {
3277 	struct sk_buff *skb = napi_frags_skb(napi);
3278 
3279 	if (!skb)
3280 		return GRO_DROP;
3281 
3282 	return napi_frags_finish(napi, skb, __napi_gro_receive(napi, skb));
3283 }
3284 EXPORT_SYMBOL(napi_gro_frags);
3285 
3286 /*
3287  * net_rps_action sends any pending IPI's for rps.
3288  * Note: called with local irq disabled, but exits with local irq enabled.
3289  */
3290 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
3291 {
3292 #ifdef CONFIG_RPS
3293 	struct softnet_data *remsd = sd->rps_ipi_list;
3294 
3295 	if (remsd) {
3296 		sd->rps_ipi_list = NULL;
3297 
3298 		local_irq_enable();
3299 
3300 		/* Send pending IPI's to kick RPS processing on remote cpus. */
3301 		while (remsd) {
3302 			struct softnet_data *next = remsd->rps_ipi_next;
3303 
3304 			if (cpu_online(remsd->cpu))
3305 				__smp_call_function_single(remsd->cpu,
3306 							   &remsd->csd, 0);
3307 			remsd = next;
3308 		}
3309 	} else
3310 #endif
3311 		local_irq_enable();
3312 }
3313 
3314 static int process_backlog(struct napi_struct *napi, int quota)
3315 {
3316 	int work = 0;
3317 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
3318 
3319 #ifdef CONFIG_RPS
3320 	/* Check if we have pending ipi, its better to send them now,
3321 	 * not waiting net_rx_action() end.
3322 	 */
3323 	if (sd->rps_ipi_list) {
3324 		local_irq_disable();
3325 		net_rps_action_and_irq_enable(sd);
3326 	}
3327 #endif
3328 	napi->weight = weight_p;
3329 	local_irq_disable();
3330 	while (work < quota) {
3331 		struct sk_buff *skb;
3332 		unsigned int qlen;
3333 
3334 		while ((skb = __skb_dequeue(&sd->process_queue))) {
3335 			local_irq_enable();
3336 			__netif_receive_skb(skb);
3337 			local_irq_disable();
3338 			input_queue_head_incr(sd);
3339 			if (++work >= quota) {
3340 				local_irq_enable();
3341 				return work;
3342 			}
3343 		}
3344 
3345 		rps_lock(sd);
3346 		qlen = skb_queue_len(&sd->input_pkt_queue);
3347 		if (qlen)
3348 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
3349 						   &sd->process_queue);
3350 
3351 		if (qlen < quota - work) {
3352 			/*
3353 			 * Inline a custom version of __napi_complete().
3354 			 * only current cpu owns and manipulates this napi,
3355 			 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
3356 			 * we can use a plain write instead of clear_bit(),
3357 			 * and we dont need an smp_mb() memory barrier.
3358 			 */
3359 			list_del(&napi->poll_list);
3360 			napi->state = 0;
3361 
3362 			quota = work + qlen;
3363 		}
3364 		rps_unlock(sd);
3365 	}
3366 	local_irq_enable();
3367 
3368 	return work;
3369 }
3370 
3371 /**
3372  * __napi_schedule - schedule for receive
3373  * @n: entry to schedule
3374  *
3375  * The entry's receive function will be scheduled to run
3376  */
3377 void __napi_schedule(struct napi_struct *n)
3378 {
3379 	unsigned long flags;
3380 
3381 	local_irq_save(flags);
3382 	____napi_schedule(&__get_cpu_var(softnet_data), n);
3383 	local_irq_restore(flags);
3384 }
3385 EXPORT_SYMBOL(__napi_schedule);
3386 
3387 void __napi_complete(struct napi_struct *n)
3388 {
3389 	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
3390 	BUG_ON(n->gro_list);
3391 
3392 	list_del(&n->poll_list);
3393 	smp_mb__before_clear_bit();
3394 	clear_bit(NAPI_STATE_SCHED, &n->state);
3395 }
3396 EXPORT_SYMBOL(__napi_complete);
3397 
3398 void napi_complete(struct napi_struct *n)
3399 {
3400 	unsigned long flags;
3401 
3402 	/*
3403 	 * don't let napi dequeue from the cpu poll list
3404 	 * just in case its running on a different cpu
3405 	 */
3406 	if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
3407 		return;
3408 
3409 	napi_gro_flush(n);
3410 	local_irq_save(flags);
3411 	__napi_complete(n);
3412 	local_irq_restore(flags);
3413 }
3414 EXPORT_SYMBOL(napi_complete);
3415 
3416 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
3417 		    int (*poll)(struct napi_struct *, int), int weight)
3418 {
3419 	INIT_LIST_HEAD(&napi->poll_list);
3420 	napi->gro_count = 0;
3421 	napi->gro_list = NULL;
3422 	napi->skb = NULL;
3423 	napi->poll = poll;
3424 	napi->weight = weight;
3425 	list_add(&napi->dev_list, &dev->napi_list);
3426 	napi->dev = dev;
3427 #ifdef CONFIG_NETPOLL
3428 	spin_lock_init(&napi->poll_lock);
3429 	napi->poll_owner = -1;
3430 #endif
3431 	set_bit(NAPI_STATE_SCHED, &napi->state);
3432 }
3433 EXPORT_SYMBOL(netif_napi_add);
3434 
3435 void netif_napi_del(struct napi_struct *napi)
3436 {
3437 	struct sk_buff *skb, *next;
3438 
3439 	list_del_init(&napi->dev_list);
3440 	napi_free_frags(napi);
3441 
3442 	for (skb = napi->gro_list; skb; skb = next) {
3443 		next = skb->next;
3444 		skb->next = NULL;
3445 		kfree_skb(skb);
3446 	}
3447 
3448 	napi->gro_list = NULL;
3449 	napi->gro_count = 0;
3450 }
3451 EXPORT_SYMBOL(netif_napi_del);
3452 
3453 static void net_rx_action(struct softirq_action *h)
3454 {
3455 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3456 	unsigned long time_limit = jiffies + 2;
3457 	int budget = netdev_budget;
3458 	void *have;
3459 
3460 	local_irq_disable();
3461 
3462 	while (!list_empty(&sd->poll_list)) {
3463 		struct napi_struct *n;
3464 		int work, weight;
3465 
3466 		/* If softirq window is exhuasted then punt.
3467 		 * Allow this to run for 2 jiffies since which will allow
3468 		 * an average latency of 1.5/HZ.
3469 		 */
3470 		if (unlikely(budget <= 0 || time_after(jiffies, time_limit)))
3471 			goto softnet_break;
3472 
3473 		local_irq_enable();
3474 
3475 		/* Even though interrupts have been re-enabled, this
3476 		 * access is safe because interrupts can only add new
3477 		 * entries to the tail of this list, and only ->poll()
3478 		 * calls can remove this head entry from the list.
3479 		 */
3480 		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
3481 
3482 		have = netpoll_poll_lock(n);
3483 
3484 		weight = n->weight;
3485 
3486 		/* This NAPI_STATE_SCHED test is for avoiding a race
3487 		 * with netpoll's poll_napi().  Only the entity which
3488 		 * obtains the lock and sees NAPI_STATE_SCHED set will
3489 		 * actually make the ->poll() call.  Therefore we avoid
3490 		 * accidently calling ->poll() when NAPI is not scheduled.
3491 		 */
3492 		work = 0;
3493 		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
3494 			work = n->poll(n, weight);
3495 			trace_napi_poll(n);
3496 		}
3497 
3498 		WARN_ON_ONCE(work > weight);
3499 
3500 		budget -= work;
3501 
3502 		local_irq_disable();
3503 
3504 		/* Drivers must not modify the NAPI state if they
3505 		 * consume the entire weight.  In such cases this code
3506 		 * still "owns" the NAPI instance and therefore can
3507 		 * move the instance around on the list at-will.
3508 		 */
3509 		if (unlikely(work == weight)) {
3510 			if (unlikely(napi_disable_pending(n))) {
3511 				local_irq_enable();
3512 				napi_complete(n);
3513 				local_irq_disable();
3514 			} else
3515 				list_move_tail(&n->poll_list, &sd->poll_list);
3516 		}
3517 
3518 		netpoll_poll_unlock(have);
3519 	}
3520 out:
3521 	net_rps_action_and_irq_enable(sd);
3522 
3523 #ifdef CONFIG_NET_DMA
3524 	/*
3525 	 * There may not be any more sk_buffs coming right now, so push
3526 	 * any pending DMA copies to hardware
3527 	 */
3528 	dma_issue_pending_all();
3529 #endif
3530 
3531 	return;
3532 
3533 softnet_break:
3534 	sd->time_squeeze++;
3535 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
3536 	goto out;
3537 }
3538 
3539 static gifconf_func_t *gifconf_list[NPROTO];
3540 
3541 /**
3542  *	register_gifconf	-	register a SIOCGIF handler
3543  *	@family: Address family
3544  *	@gifconf: Function handler
3545  *
3546  *	Register protocol dependent address dumping routines. The handler
3547  *	that is passed must not be freed or reused until it has been replaced
3548  *	by another handler.
3549  */
3550 int register_gifconf(unsigned int family, gifconf_func_t *gifconf)
3551 {
3552 	if (family >= NPROTO)
3553 		return -EINVAL;
3554 	gifconf_list[family] = gifconf;
3555 	return 0;
3556 }
3557 EXPORT_SYMBOL(register_gifconf);
3558 
3559 
3560 /*
3561  *	Map an interface index to its name (SIOCGIFNAME)
3562  */
3563 
3564 /*
3565  *	We need this ioctl for efficient implementation of the
3566  *	if_indextoname() function required by the IPv6 API.  Without
3567  *	it, we would have to search all the interfaces to find a
3568  *	match.  --pb
3569  */
3570 
3571 static int dev_ifname(struct net *net, struct ifreq __user *arg)
3572 {
3573 	struct net_device *dev;
3574 	struct ifreq ifr;
3575 
3576 	/*
3577 	 *	Fetch the caller's info block.
3578 	 */
3579 
3580 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
3581 		return -EFAULT;
3582 
3583 	rcu_read_lock();
3584 	dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex);
3585 	if (!dev) {
3586 		rcu_read_unlock();
3587 		return -ENODEV;
3588 	}
3589 
3590 	strcpy(ifr.ifr_name, dev->name);
3591 	rcu_read_unlock();
3592 
3593 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
3594 		return -EFAULT;
3595 	return 0;
3596 }
3597 
3598 /*
3599  *	Perform a SIOCGIFCONF call. This structure will change
3600  *	size eventually, and there is nothing I can do about it.
3601  *	Thus we will need a 'compatibility mode'.
3602  */
3603 
3604 static int dev_ifconf(struct net *net, char __user *arg)
3605 {
3606 	struct ifconf ifc;
3607 	struct net_device *dev;
3608 	char __user *pos;
3609 	int len;
3610 	int total;
3611 	int i;
3612 
3613 	/*
3614 	 *	Fetch the caller's info block.
3615 	 */
3616 
3617 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
3618 		return -EFAULT;
3619 
3620 	pos = ifc.ifc_buf;
3621 	len = ifc.ifc_len;
3622 
3623 	/*
3624 	 *	Loop over the interfaces, and write an info block for each.
3625 	 */
3626 
3627 	total = 0;
3628 	for_each_netdev(net, dev) {
3629 		for (i = 0; i < NPROTO; i++) {
3630 			if (gifconf_list[i]) {
3631 				int done;
3632 				if (!pos)
3633 					done = gifconf_list[i](dev, NULL, 0);
3634 				else
3635 					done = gifconf_list[i](dev, pos + total,
3636 							       len - total);
3637 				if (done < 0)
3638 					return -EFAULT;
3639 				total += done;
3640 			}
3641 		}
3642 	}
3643 
3644 	/*
3645 	 *	All done.  Write the updated control block back to the caller.
3646 	 */
3647 	ifc.ifc_len = total;
3648 
3649 	/*
3650 	 * 	Both BSD and Solaris return 0 here, so we do too.
3651 	 */
3652 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
3653 }
3654 
3655 #ifdef CONFIG_PROC_FS
3656 /*
3657  *	This is invoked by the /proc filesystem handler to display a device
3658  *	in detail.
3659  */
3660 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
3661 	__acquires(RCU)
3662 {
3663 	struct net *net = seq_file_net(seq);
3664 	loff_t off;
3665 	struct net_device *dev;
3666 
3667 	rcu_read_lock();
3668 	if (!*pos)
3669 		return SEQ_START_TOKEN;
3670 
3671 	off = 1;
3672 	for_each_netdev_rcu(net, dev)
3673 		if (off++ == *pos)
3674 			return dev;
3675 
3676 	return NULL;
3677 }
3678 
3679 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3680 {
3681 	struct net_device *dev = (v == SEQ_START_TOKEN) ?
3682 				  first_net_device(seq_file_net(seq)) :
3683 				  next_net_device((struct net_device *)v);
3684 
3685 	++*pos;
3686 	return rcu_dereference(dev);
3687 }
3688 
3689 void dev_seq_stop(struct seq_file *seq, void *v)
3690 	__releases(RCU)
3691 {
3692 	rcu_read_unlock();
3693 }
3694 
3695 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
3696 {
3697 	const struct net_device_stats *stats = dev_get_stats(dev);
3698 
3699 	seq_printf(seq, "%6s: %7lu %7lu %4lu %4lu %4lu %5lu %10lu %9lu "
3700 		   "%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
3701 		   dev->name, stats->rx_bytes, stats->rx_packets,
3702 		   stats->rx_errors,
3703 		   stats->rx_dropped + stats->rx_missed_errors,
3704 		   stats->rx_fifo_errors,
3705 		   stats->rx_length_errors + stats->rx_over_errors +
3706 		    stats->rx_crc_errors + stats->rx_frame_errors,
3707 		   stats->rx_compressed, stats->multicast,
3708 		   stats->tx_bytes, stats->tx_packets,
3709 		   stats->tx_errors, stats->tx_dropped,
3710 		   stats->tx_fifo_errors, stats->collisions,
3711 		   stats->tx_carrier_errors +
3712 		    stats->tx_aborted_errors +
3713 		    stats->tx_window_errors +
3714 		    stats->tx_heartbeat_errors,
3715 		   stats->tx_compressed);
3716 }
3717 
3718 /*
3719  *	Called from the PROCfs module. This now uses the new arbitrary sized
3720  *	/proc/net interface to create /proc/net/dev
3721  */
3722 static int dev_seq_show(struct seq_file *seq, void *v)
3723 {
3724 	if (v == SEQ_START_TOKEN)
3725 		seq_puts(seq, "Inter-|   Receive                            "
3726 			      "                    |  Transmit\n"
3727 			      " face |bytes    packets errs drop fifo frame "
3728 			      "compressed multicast|bytes    packets errs "
3729 			      "drop fifo colls carrier compressed\n");
3730 	else
3731 		dev_seq_printf_stats(seq, v);
3732 	return 0;
3733 }
3734 
3735 static struct softnet_data *softnet_get_online(loff_t *pos)
3736 {
3737 	struct softnet_data *sd = NULL;
3738 
3739 	while (*pos < nr_cpu_ids)
3740 		if (cpu_online(*pos)) {
3741 			sd = &per_cpu(softnet_data, *pos);
3742 			break;
3743 		} else
3744 			++*pos;
3745 	return sd;
3746 }
3747 
3748 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
3749 {
3750 	return softnet_get_online(pos);
3751 }
3752 
3753 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3754 {
3755 	++*pos;
3756 	return softnet_get_online(pos);
3757 }
3758 
3759 static void softnet_seq_stop(struct seq_file *seq, void *v)
3760 {
3761 }
3762 
3763 static int softnet_seq_show(struct seq_file *seq, void *v)
3764 {
3765 	struct softnet_data *sd = v;
3766 
3767 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
3768 		   sd->processed, sd->dropped, sd->time_squeeze, 0,
3769 		   0, 0, 0, 0, /* was fastroute */
3770 		   sd->cpu_collision, sd->received_rps);
3771 	return 0;
3772 }
3773 
3774 static const struct seq_operations dev_seq_ops = {
3775 	.start = dev_seq_start,
3776 	.next  = dev_seq_next,
3777 	.stop  = dev_seq_stop,
3778 	.show  = dev_seq_show,
3779 };
3780 
3781 static int dev_seq_open(struct inode *inode, struct file *file)
3782 {
3783 	return seq_open_net(inode, file, &dev_seq_ops,
3784 			    sizeof(struct seq_net_private));
3785 }
3786 
3787 static const struct file_operations dev_seq_fops = {
3788 	.owner	 = THIS_MODULE,
3789 	.open    = dev_seq_open,
3790 	.read    = seq_read,
3791 	.llseek  = seq_lseek,
3792 	.release = seq_release_net,
3793 };
3794 
3795 static const struct seq_operations softnet_seq_ops = {
3796 	.start = softnet_seq_start,
3797 	.next  = softnet_seq_next,
3798 	.stop  = softnet_seq_stop,
3799 	.show  = softnet_seq_show,
3800 };
3801 
3802 static int softnet_seq_open(struct inode *inode, struct file *file)
3803 {
3804 	return seq_open(file, &softnet_seq_ops);
3805 }
3806 
3807 static const struct file_operations softnet_seq_fops = {
3808 	.owner	 = THIS_MODULE,
3809 	.open    = softnet_seq_open,
3810 	.read    = seq_read,
3811 	.llseek  = seq_lseek,
3812 	.release = seq_release,
3813 };
3814 
3815 static void *ptype_get_idx(loff_t pos)
3816 {
3817 	struct packet_type *pt = NULL;
3818 	loff_t i = 0;
3819 	int t;
3820 
3821 	list_for_each_entry_rcu(pt, &ptype_all, list) {
3822 		if (i == pos)
3823 			return pt;
3824 		++i;
3825 	}
3826 
3827 	for (t = 0; t < PTYPE_HASH_SIZE; t++) {
3828 		list_for_each_entry_rcu(pt, &ptype_base[t], list) {
3829 			if (i == pos)
3830 				return pt;
3831 			++i;
3832 		}
3833 	}
3834 	return NULL;
3835 }
3836 
3837 static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
3838 	__acquires(RCU)
3839 {
3840 	rcu_read_lock();
3841 	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
3842 }
3843 
3844 static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3845 {
3846 	struct packet_type *pt;
3847 	struct list_head *nxt;
3848 	int hash;
3849 
3850 	++*pos;
3851 	if (v == SEQ_START_TOKEN)
3852 		return ptype_get_idx(0);
3853 
3854 	pt = v;
3855 	nxt = pt->list.next;
3856 	if (pt->type == htons(ETH_P_ALL)) {
3857 		if (nxt != &ptype_all)
3858 			goto found;
3859 		hash = 0;
3860 		nxt = ptype_base[0].next;
3861 	} else
3862 		hash = ntohs(pt->type) & PTYPE_HASH_MASK;
3863 
3864 	while (nxt == &ptype_base[hash]) {
3865 		if (++hash >= PTYPE_HASH_SIZE)
3866 			return NULL;
3867 		nxt = ptype_base[hash].next;
3868 	}
3869 found:
3870 	return list_entry(nxt, struct packet_type, list);
3871 }
3872 
3873 static void ptype_seq_stop(struct seq_file *seq, void *v)
3874 	__releases(RCU)
3875 {
3876 	rcu_read_unlock();
3877 }
3878 
3879 static int ptype_seq_show(struct seq_file *seq, void *v)
3880 {
3881 	struct packet_type *pt = v;
3882 
3883 	if (v == SEQ_START_TOKEN)
3884 		seq_puts(seq, "Type Device      Function\n");
3885 	else if (pt->dev == NULL || dev_net(pt->dev) == seq_file_net(seq)) {
3886 		if (pt->type == htons(ETH_P_ALL))
3887 			seq_puts(seq, "ALL ");
3888 		else
3889 			seq_printf(seq, "%04x", ntohs(pt->type));
3890 
3891 		seq_printf(seq, " %-8s %pF\n",
3892 			   pt->dev ? pt->dev->name : "", pt->func);
3893 	}
3894 
3895 	return 0;
3896 }
3897 
3898 static const struct seq_operations ptype_seq_ops = {
3899 	.start = ptype_seq_start,
3900 	.next  = ptype_seq_next,
3901 	.stop  = ptype_seq_stop,
3902 	.show  = ptype_seq_show,
3903 };
3904 
3905 static int ptype_seq_open(struct inode *inode, struct file *file)
3906 {
3907 	return seq_open_net(inode, file, &ptype_seq_ops,
3908 			sizeof(struct seq_net_private));
3909 }
3910 
3911 static const struct file_operations ptype_seq_fops = {
3912 	.owner	 = THIS_MODULE,
3913 	.open    = ptype_seq_open,
3914 	.read    = seq_read,
3915 	.llseek  = seq_lseek,
3916 	.release = seq_release_net,
3917 };
3918 
3919 
3920 static int __net_init dev_proc_net_init(struct net *net)
3921 {
3922 	int rc = -ENOMEM;
3923 
3924 	if (!proc_net_fops_create(net, "dev", S_IRUGO, &dev_seq_fops))
3925 		goto out;
3926 	if (!proc_net_fops_create(net, "softnet_stat", S_IRUGO, &softnet_seq_fops))
3927 		goto out_dev;
3928 	if (!proc_net_fops_create(net, "ptype", S_IRUGO, &ptype_seq_fops))
3929 		goto out_softnet;
3930 
3931 	if (wext_proc_init(net))
3932 		goto out_ptype;
3933 	rc = 0;
3934 out:
3935 	return rc;
3936 out_ptype:
3937 	proc_net_remove(net, "ptype");
3938 out_softnet:
3939 	proc_net_remove(net, "softnet_stat");
3940 out_dev:
3941 	proc_net_remove(net, "dev");
3942 	goto out;
3943 }
3944 
3945 static void __net_exit dev_proc_net_exit(struct net *net)
3946 {
3947 	wext_proc_exit(net);
3948 
3949 	proc_net_remove(net, "ptype");
3950 	proc_net_remove(net, "softnet_stat");
3951 	proc_net_remove(net, "dev");
3952 }
3953 
3954 static struct pernet_operations __net_initdata dev_proc_ops = {
3955 	.init = dev_proc_net_init,
3956 	.exit = dev_proc_net_exit,
3957 };
3958 
3959 static int __init dev_proc_init(void)
3960 {
3961 	return register_pernet_subsys(&dev_proc_ops);
3962 }
3963 #else
3964 #define dev_proc_init() 0
3965 #endif	/* CONFIG_PROC_FS */
3966 
3967 
3968 /**
3969  *	netdev_set_master	-	set up master/slave pair
3970  *	@slave: slave device
3971  *	@master: new master device
3972  *
3973  *	Changes the master device of the slave. Pass %NULL to break the
3974  *	bonding. The caller must hold the RTNL semaphore. On a failure
3975  *	a negative errno code is returned. On success the reference counts
3976  *	are adjusted, %RTM_NEWLINK is sent to the routing socket and the
3977  *	function returns zero.
3978  */
3979 int netdev_set_master(struct net_device *slave, struct net_device *master)
3980 {
3981 	struct net_device *old = slave->master;
3982 
3983 	ASSERT_RTNL();
3984 
3985 	if (master) {
3986 		if (old)
3987 			return -EBUSY;
3988 		dev_hold(master);
3989 	}
3990 
3991 	slave->master = master;
3992 
3993 	if (old) {
3994 		synchronize_net();
3995 		dev_put(old);
3996 	}
3997 	if (master)
3998 		slave->flags |= IFF_SLAVE;
3999 	else
4000 		slave->flags &= ~IFF_SLAVE;
4001 
4002 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
4003 	return 0;
4004 }
4005 EXPORT_SYMBOL(netdev_set_master);
4006 
4007 static void dev_change_rx_flags(struct net_device *dev, int flags)
4008 {
4009 	const struct net_device_ops *ops = dev->netdev_ops;
4010 
4011 	if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
4012 		ops->ndo_change_rx_flags(dev, flags);
4013 }
4014 
4015 static int __dev_set_promiscuity(struct net_device *dev, int inc)
4016 {
4017 	unsigned short old_flags = dev->flags;
4018 	uid_t uid;
4019 	gid_t gid;
4020 
4021 	ASSERT_RTNL();
4022 
4023 	dev->flags |= IFF_PROMISC;
4024 	dev->promiscuity += inc;
4025 	if (dev->promiscuity == 0) {
4026 		/*
4027 		 * Avoid overflow.
4028 		 * If inc causes overflow, untouch promisc and return error.
4029 		 */
4030 		if (inc < 0)
4031 			dev->flags &= ~IFF_PROMISC;
4032 		else {
4033 			dev->promiscuity -= inc;
4034 			printk(KERN_WARNING "%s: promiscuity touches roof, "
4035 				"set promiscuity failed, promiscuity feature "
4036 				"of device might be broken.\n", dev->name);
4037 			return -EOVERFLOW;
4038 		}
4039 	}
4040 	if (dev->flags != old_flags) {
4041 		printk(KERN_INFO "device %s %s promiscuous mode\n",
4042 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
4043 							       "left");
4044 		if (audit_enabled) {
4045 			current_uid_gid(&uid, &gid);
4046 			audit_log(current->audit_context, GFP_ATOMIC,
4047 				AUDIT_ANOM_PROMISCUOUS,
4048 				"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
4049 				dev->name, (dev->flags & IFF_PROMISC),
4050 				(old_flags & IFF_PROMISC),
4051 				audit_get_loginuid(current),
4052 				uid, gid,
4053 				audit_get_sessionid(current));
4054 		}
4055 
4056 		dev_change_rx_flags(dev, IFF_PROMISC);
4057 	}
4058 	return 0;
4059 }
4060 
4061 /**
4062  *	dev_set_promiscuity	- update promiscuity count on a device
4063  *	@dev: device
4064  *	@inc: modifier
4065  *
4066  *	Add or remove promiscuity from a device. While the count in the device
4067  *	remains above zero the interface remains promiscuous. Once it hits zero
4068  *	the device reverts back to normal filtering operation. A negative inc
4069  *	value is used to drop promiscuity on the device.
4070  *	Return 0 if successful or a negative errno code on error.
4071  */
4072 int dev_set_promiscuity(struct net_device *dev, int inc)
4073 {
4074 	unsigned short old_flags = dev->flags;
4075 	int err;
4076 
4077 	err = __dev_set_promiscuity(dev, inc);
4078 	if (err < 0)
4079 		return err;
4080 	if (dev->flags != old_flags)
4081 		dev_set_rx_mode(dev);
4082 	return err;
4083 }
4084 EXPORT_SYMBOL(dev_set_promiscuity);
4085 
4086 /**
4087  *	dev_set_allmulti	- update allmulti count on a device
4088  *	@dev: device
4089  *	@inc: modifier
4090  *
4091  *	Add or remove reception of all multicast frames to a device. While the
4092  *	count in the device remains above zero the interface remains listening
4093  *	to all interfaces. Once it hits zero the device reverts back to normal
4094  *	filtering operation. A negative @inc value is used to drop the counter
4095  *	when releasing a resource needing all multicasts.
4096  *	Return 0 if successful or a negative errno code on error.
4097  */
4098 
4099 int dev_set_allmulti(struct net_device *dev, int inc)
4100 {
4101 	unsigned short old_flags = dev->flags;
4102 
4103 	ASSERT_RTNL();
4104 
4105 	dev->flags |= IFF_ALLMULTI;
4106 	dev->allmulti += inc;
4107 	if (dev->allmulti == 0) {
4108 		/*
4109 		 * Avoid overflow.
4110 		 * If inc causes overflow, untouch allmulti and return error.
4111 		 */
4112 		if (inc < 0)
4113 			dev->flags &= ~IFF_ALLMULTI;
4114 		else {
4115 			dev->allmulti -= inc;
4116 			printk(KERN_WARNING "%s: allmulti touches roof, "
4117 				"set allmulti failed, allmulti feature of "
4118 				"device might be broken.\n", dev->name);
4119 			return -EOVERFLOW;
4120 		}
4121 	}
4122 	if (dev->flags ^ old_flags) {
4123 		dev_change_rx_flags(dev, IFF_ALLMULTI);
4124 		dev_set_rx_mode(dev);
4125 	}
4126 	return 0;
4127 }
4128 EXPORT_SYMBOL(dev_set_allmulti);
4129 
4130 /*
4131  *	Upload unicast and multicast address lists to device and
4132  *	configure RX filtering. When the device doesn't support unicast
4133  *	filtering it is put in promiscuous mode while unicast addresses
4134  *	are present.
4135  */
4136 void __dev_set_rx_mode(struct net_device *dev)
4137 {
4138 	const struct net_device_ops *ops = dev->netdev_ops;
4139 
4140 	/* dev_open will call this function so the list will stay sane. */
4141 	if (!(dev->flags&IFF_UP))
4142 		return;
4143 
4144 	if (!netif_device_present(dev))
4145 		return;
4146 
4147 	if (ops->ndo_set_rx_mode)
4148 		ops->ndo_set_rx_mode(dev);
4149 	else {
4150 		/* Unicast addresses changes may only happen under the rtnl,
4151 		 * therefore calling __dev_set_promiscuity here is safe.
4152 		 */
4153 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4154 			__dev_set_promiscuity(dev, 1);
4155 			dev->uc_promisc = 1;
4156 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4157 			__dev_set_promiscuity(dev, -1);
4158 			dev->uc_promisc = 0;
4159 		}
4160 
4161 		if (ops->ndo_set_multicast_list)
4162 			ops->ndo_set_multicast_list(dev);
4163 	}
4164 }
4165 
4166 void dev_set_rx_mode(struct net_device *dev)
4167 {
4168 	netif_addr_lock_bh(dev);
4169 	__dev_set_rx_mode(dev);
4170 	netif_addr_unlock_bh(dev);
4171 }
4172 
4173 /**
4174  *	dev_get_flags - get flags reported to userspace
4175  *	@dev: device
4176  *
4177  *	Get the combination of flag bits exported through APIs to userspace.
4178  */
4179 unsigned dev_get_flags(const struct net_device *dev)
4180 {
4181 	unsigned flags;
4182 
4183 	flags = (dev->flags & ~(IFF_PROMISC |
4184 				IFF_ALLMULTI |
4185 				IFF_RUNNING |
4186 				IFF_LOWER_UP |
4187 				IFF_DORMANT)) |
4188 		(dev->gflags & (IFF_PROMISC |
4189 				IFF_ALLMULTI));
4190 
4191 	if (netif_running(dev)) {
4192 		if (netif_oper_up(dev))
4193 			flags |= IFF_RUNNING;
4194 		if (netif_carrier_ok(dev))
4195 			flags |= IFF_LOWER_UP;
4196 		if (netif_dormant(dev))
4197 			flags |= IFF_DORMANT;
4198 	}
4199 
4200 	return flags;
4201 }
4202 EXPORT_SYMBOL(dev_get_flags);
4203 
4204 int __dev_change_flags(struct net_device *dev, unsigned int flags)
4205 {
4206 	int old_flags = dev->flags;
4207 	int ret;
4208 
4209 	ASSERT_RTNL();
4210 
4211 	/*
4212 	 *	Set the flags on our device.
4213 	 */
4214 
4215 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
4216 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
4217 			       IFF_AUTOMEDIA)) |
4218 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
4219 				    IFF_ALLMULTI));
4220 
4221 	/*
4222 	 *	Load in the correct multicast list now the flags have changed.
4223 	 */
4224 
4225 	if ((old_flags ^ flags) & IFF_MULTICAST)
4226 		dev_change_rx_flags(dev, IFF_MULTICAST);
4227 
4228 	dev_set_rx_mode(dev);
4229 
4230 	/*
4231 	 *	Have we downed the interface. We handle IFF_UP ourselves
4232 	 *	according to user attempts to set it, rather than blindly
4233 	 *	setting it.
4234 	 */
4235 
4236 	ret = 0;
4237 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
4238 		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
4239 
4240 		if (!ret)
4241 			dev_set_rx_mode(dev);
4242 	}
4243 
4244 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
4245 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
4246 
4247 		dev->gflags ^= IFF_PROMISC;
4248 		dev_set_promiscuity(dev, inc);
4249 	}
4250 
4251 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
4252 	   is important. Some (broken) drivers set IFF_PROMISC, when
4253 	   IFF_ALLMULTI is requested not asking us and not reporting.
4254 	 */
4255 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
4256 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
4257 
4258 		dev->gflags ^= IFF_ALLMULTI;
4259 		dev_set_allmulti(dev, inc);
4260 	}
4261 
4262 	return ret;
4263 }
4264 
4265 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
4266 {
4267 	unsigned int changes = dev->flags ^ old_flags;
4268 
4269 	if (changes & IFF_UP) {
4270 		if (dev->flags & IFF_UP)
4271 			call_netdevice_notifiers(NETDEV_UP, dev);
4272 		else
4273 			call_netdevice_notifiers(NETDEV_DOWN, dev);
4274 	}
4275 
4276 	if (dev->flags & IFF_UP &&
4277 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE)))
4278 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
4279 }
4280 
4281 /**
4282  *	dev_change_flags - change device settings
4283  *	@dev: device
4284  *	@flags: device state flags
4285  *
4286  *	Change settings on device based state flags. The flags are
4287  *	in the userspace exported format.
4288  */
4289 int dev_change_flags(struct net_device *dev, unsigned flags)
4290 {
4291 	int ret, changes;
4292 	int old_flags = dev->flags;
4293 
4294 	ret = __dev_change_flags(dev, flags);
4295 	if (ret < 0)
4296 		return ret;
4297 
4298 	changes = old_flags ^ dev->flags;
4299 	if (changes)
4300 		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
4301 
4302 	__dev_notify_flags(dev, old_flags);
4303 	return ret;
4304 }
4305 EXPORT_SYMBOL(dev_change_flags);
4306 
4307 /**
4308  *	dev_set_mtu - Change maximum transfer unit
4309  *	@dev: device
4310  *	@new_mtu: new transfer unit
4311  *
4312  *	Change the maximum transfer size of the network device.
4313  */
4314 int dev_set_mtu(struct net_device *dev, int new_mtu)
4315 {
4316 	const struct net_device_ops *ops = dev->netdev_ops;
4317 	int err;
4318 
4319 	if (new_mtu == dev->mtu)
4320 		return 0;
4321 
4322 	/*	MTU must be positive.	 */
4323 	if (new_mtu < 0)
4324 		return -EINVAL;
4325 
4326 	if (!netif_device_present(dev))
4327 		return -ENODEV;
4328 
4329 	err = 0;
4330 	if (ops->ndo_change_mtu)
4331 		err = ops->ndo_change_mtu(dev, new_mtu);
4332 	else
4333 		dev->mtu = new_mtu;
4334 
4335 	if (!err && dev->flags & IFF_UP)
4336 		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
4337 	return err;
4338 }
4339 EXPORT_SYMBOL(dev_set_mtu);
4340 
4341 /**
4342  *	dev_set_mac_address - Change Media Access Control Address
4343  *	@dev: device
4344  *	@sa: new address
4345  *
4346  *	Change the hardware (MAC) address of the device
4347  */
4348 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
4349 {
4350 	const struct net_device_ops *ops = dev->netdev_ops;
4351 	int err;
4352 
4353 	if (!ops->ndo_set_mac_address)
4354 		return -EOPNOTSUPP;
4355 	if (sa->sa_family != dev->type)
4356 		return -EINVAL;
4357 	if (!netif_device_present(dev))
4358 		return -ENODEV;
4359 	err = ops->ndo_set_mac_address(dev, sa);
4360 	if (!err)
4361 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4362 	return err;
4363 }
4364 EXPORT_SYMBOL(dev_set_mac_address);
4365 
4366 /*
4367  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
4368  */
4369 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
4370 {
4371 	int err;
4372 	struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
4373 
4374 	if (!dev)
4375 		return -ENODEV;
4376 
4377 	switch (cmd) {
4378 	case SIOCGIFFLAGS:	/* Get interface flags */
4379 		ifr->ifr_flags = (short) dev_get_flags(dev);
4380 		return 0;
4381 
4382 	case SIOCGIFMETRIC:	/* Get the metric on the interface
4383 				   (currently unused) */
4384 		ifr->ifr_metric = 0;
4385 		return 0;
4386 
4387 	case SIOCGIFMTU:	/* Get the MTU of a device */
4388 		ifr->ifr_mtu = dev->mtu;
4389 		return 0;
4390 
4391 	case SIOCGIFHWADDR:
4392 		if (!dev->addr_len)
4393 			memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
4394 		else
4395 			memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
4396 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4397 		ifr->ifr_hwaddr.sa_family = dev->type;
4398 		return 0;
4399 
4400 	case SIOCGIFSLAVE:
4401 		err = -EINVAL;
4402 		break;
4403 
4404 	case SIOCGIFMAP:
4405 		ifr->ifr_map.mem_start = dev->mem_start;
4406 		ifr->ifr_map.mem_end   = dev->mem_end;
4407 		ifr->ifr_map.base_addr = dev->base_addr;
4408 		ifr->ifr_map.irq       = dev->irq;
4409 		ifr->ifr_map.dma       = dev->dma;
4410 		ifr->ifr_map.port      = dev->if_port;
4411 		return 0;
4412 
4413 	case SIOCGIFINDEX:
4414 		ifr->ifr_ifindex = dev->ifindex;
4415 		return 0;
4416 
4417 	case SIOCGIFTXQLEN:
4418 		ifr->ifr_qlen = dev->tx_queue_len;
4419 		return 0;
4420 
4421 	default:
4422 		/* dev_ioctl() should ensure this case
4423 		 * is never reached
4424 		 */
4425 		WARN_ON(1);
4426 		err = -EINVAL;
4427 		break;
4428 
4429 	}
4430 	return err;
4431 }
4432 
4433 /*
4434  *	Perform the SIOCxIFxxx calls, inside rtnl_lock()
4435  */
4436 static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
4437 {
4438 	int err;
4439 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
4440 	const struct net_device_ops *ops;
4441 
4442 	if (!dev)
4443 		return -ENODEV;
4444 
4445 	ops = dev->netdev_ops;
4446 
4447 	switch (cmd) {
4448 	case SIOCSIFFLAGS:	/* Set interface flags */
4449 		return dev_change_flags(dev, ifr->ifr_flags);
4450 
4451 	case SIOCSIFMETRIC:	/* Set the metric on the interface
4452 				   (currently unused) */
4453 		return -EOPNOTSUPP;
4454 
4455 	case SIOCSIFMTU:	/* Set the MTU of a device */
4456 		return dev_set_mtu(dev, ifr->ifr_mtu);
4457 
4458 	case SIOCSIFHWADDR:
4459 		return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
4460 
4461 	case SIOCSIFHWBROADCAST:
4462 		if (ifr->ifr_hwaddr.sa_family != dev->type)
4463 			return -EINVAL;
4464 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
4465 		       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4466 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4467 		return 0;
4468 
4469 	case SIOCSIFMAP:
4470 		if (ops->ndo_set_config) {
4471 			if (!netif_device_present(dev))
4472 				return -ENODEV;
4473 			return ops->ndo_set_config(dev, &ifr->ifr_map);
4474 		}
4475 		return -EOPNOTSUPP;
4476 
4477 	case SIOCADDMULTI:
4478 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4479 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4480 			return -EINVAL;
4481 		if (!netif_device_present(dev))
4482 			return -ENODEV;
4483 		return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
4484 
4485 	case SIOCDELMULTI:
4486 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4487 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4488 			return -EINVAL;
4489 		if (!netif_device_present(dev))
4490 			return -ENODEV;
4491 		return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
4492 
4493 	case SIOCSIFTXQLEN:
4494 		if (ifr->ifr_qlen < 0)
4495 			return -EINVAL;
4496 		dev->tx_queue_len = ifr->ifr_qlen;
4497 		return 0;
4498 
4499 	case SIOCSIFNAME:
4500 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
4501 		return dev_change_name(dev, ifr->ifr_newname);
4502 
4503 	/*
4504 	 *	Unknown or private ioctl
4505 	 */
4506 	default:
4507 		if ((cmd >= SIOCDEVPRIVATE &&
4508 		    cmd <= SIOCDEVPRIVATE + 15) ||
4509 		    cmd == SIOCBONDENSLAVE ||
4510 		    cmd == SIOCBONDRELEASE ||
4511 		    cmd == SIOCBONDSETHWADDR ||
4512 		    cmd == SIOCBONDSLAVEINFOQUERY ||
4513 		    cmd == SIOCBONDINFOQUERY ||
4514 		    cmd == SIOCBONDCHANGEACTIVE ||
4515 		    cmd == SIOCGMIIPHY ||
4516 		    cmd == SIOCGMIIREG ||
4517 		    cmd == SIOCSMIIREG ||
4518 		    cmd == SIOCBRADDIF ||
4519 		    cmd == SIOCBRDELIF ||
4520 		    cmd == SIOCSHWTSTAMP ||
4521 		    cmd == SIOCWANDEV) {
4522 			err = -EOPNOTSUPP;
4523 			if (ops->ndo_do_ioctl) {
4524 				if (netif_device_present(dev))
4525 					err = ops->ndo_do_ioctl(dev, ifr, cmd);
4526 				else
4527 					err = -ENODEV;
4528 			}
4529 		} else
4530 			err = -EINVAL;
4531 
4532 	}
4533 	return err;
4534 }
4535 
4536 /*
4537  *	This function handles all "interface"-type I/O control requests. The actual
4538  *	'doing' part of this is dev_ifsioc above.
4539  */
4540 
4541 /**
4542  *	dev_ioctl	-	network device ioctl
4543  *	@net: the applicable net namespace
4544  *	@cmd: command to issue
4545  *	@arg: pointer to a struct ifreq in user space
4546  *
4547  *	Issue ioctl functions to devices. This is normally called by the
4548  *	user space syscall interfaces but can sometimes be useful for
4549  *	other purposes. The return value is the return from the syscall if
4550  *	positive or a negative errno code on error.
4551  */
4552 
4553 int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
4554 {
4555 	struct ifreq ifr;
4556 	int ret;
4557 	char *colon;
4558 
4559 	/* One special case: SIOCGIFCONF takes ifconf argument
4560 	   and requires shared lock, because it sleeps writing
4561 	   to user space.
4562 	 */
4563 
4564 	if (cmd == SIOCGIFCONF) {
4565 		rtnl_lock();
4566 		ret = dev_ifconf(net, (char __user *) arg);
4567 		rtnl_unlock();
4568 		return ret;
4569 	}
4570 	if (cmd == SIOCGIFNAME)
4571 		return dev_ifname(net, (struct ifreq __user *)arg);
4572 
4573 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
4574 		return -EFAULT;
4575 
4576 	ifr.ifr_name[IFNAMSIZ-1] = 0;
4577 
4578 	colon = strchr(ifr.ifr_name, ':');
4579 	if (colon)
4580 		*colon = 0;
4581 
4582 	/*
4583 	 *	See which interface the caller is talking about.
4584 	 */
4585 
4586 	switch (cmd) {
4587 	/*
4588 	 *	These ioctl calls:
4589 	 *	- can be done by all.
4590 	 *	- atomic and do not require locking.
4591 	 *	- return a value
4592 	 */
4593 	case SIOCGIFFLAGS:
4594 	case SIOCGIFMETRIC:
4595 	case SIOCGIFMTU:
4596 	case SIOCGIFHWADDR:
4597 	case SIOCGIFSLAVE:
4598 	case SIOCGIFMAP:
4599 	case SIOCGIFINDEX:
4600 	case SIOCGIFTXQLEN:
4601 		dev_load(net, ifr.ifr_name);
4602 		rcu_read_lock();
4603 		ret = dev_ifsioc_locked(net, &ifr, cmd);
4604 		rcu_read_unlock();
4605 		if (!ret) {
4606 			if (colon)
4607 				*colon = ':';
4608 			if (copy_to_user(arg, &ifr,
4609 					 sizeof(struct ifreq)))
4610 				ret = -EFAULT;
4611 		}
4612 		return ret;
4613 
4614 	case SIOCETHTOOL:
4615 		dev_load(net, ifr.ifr_name);
4616 		rtnl_lock();
4617 		ret = dev_ethtool(net, &ifr);
4618 		rtnl_unlock();
4619 		if (!ret) {
4620 			if (colon)
4621 				*colon = ':';
4622 			if (copy_to_user(arg, &ifr,
4623 					 sizeof(struct ifreq)))
4624 				ret = -EFAULT;
4625 		}
4626 		return ret;
4627 
4628 	/*
4629 	 *	These ioctl calls:
4630 	 *	- require superuser power.
4631 	 *	- require strict serialization.
4632 	 *	- return a value
4633 	 */
4634 	case SIOCGMIIPHY:
4635 	case SIOCGMIIREG:
4636 	case SIOCSIFNAME:
4637 		if (!capable(CAP_NET_ADMIN))
4638 			return -EPERM;
4639 		dev_load(net, ifr.ifr_name);
4640 		rtnl_lock();
4641 		ret = dev_ifsioc(net, &ifr, cmd);
4642 		rtnl_unlock();
4643 		if (!ret) {
4644 			if (colon)
4645 				*colon = ':';
4646 			if (copy_to_user(arg, &ifr,
4647 					 sizeof(struct ifreq)))
4648 				ret = -EFAULT;
4649 		}
4650 		return ret;
4651 
4652 	/*
4653 	 *	These ioctl calls:
4654 	 *	- require superuser power.
4655 	 *	- require strict serialization.
4656 	 *	- do not return a value
4657 	 */
4658 	case SIOCSIFFLAGS:
4659 	case SIOCSIFMETRIC:
4660 	case SIOCSIFMTU:
4661 	case SIOCSIFMAP:
4662 	case SIOCSIFHWADDR:
4663 	case SIOCSIFSLAVE:
4664 	case SIOCADDMULTI:
4665 	case SIOCDELMULTI:
4666 	case SIOCSIFHWBROADCAST:
4667 	case SIOCSIFTXQLEN:
4668 	case SIOCSMIIREG:
4669 	case SIOCBONDENSLAVE:
4670 	case SIOCBONDRELEASE:
4671 	case SIOCBONDSETHWADDR:
4672 	case SIOCBONDCHANGEACTIVE:
4673 	case SIOCBRADDIF:
4674 	case SIOCBRDELIF:
4675 	case SIOCSHWTSTAMP:
4676 		if (!capable(CAP_NET_ADMIN))
4677 			return -EPERM;
4678 		/* fall through */
4679 	case SIOCBONDSLAVEINFOQUERY:
4680 	case SIOCBONDINFOQUERY:
4681 		dev_load(net, ifr.ifr_name);
4682 		rtnl_lock();
4683 		ret = dev_ifsioc(net, &ifr, cmd);
4684 		rtnl_unlock();
4685 		return ret;
4686 
4687 	case SIOCGIFMEM:
4688 		/* Get the per device memory space. We can add this but
4689 		 * currently do not support it */
4690 	case SIOCSIFMEM:
4691 		/* Set the per device memory buffer space.
4692 		 * Not applicable in our case */
4693 	case SIOCSIFLINK:
4694 		return -EINVAL;
4695 
4696 	/*
4697 	 *	Unknown or private ioctl.
4698 	 */
4699 	default:
4700 		if (cmd == SIOCWANDEV ||
4701 		    (cmd >= SIOCDEVPRIVATE &&
4702 		     cmd <= SIOCDEVPRIVATE + 15)) {
4703 			dev_load(net, ifr.ifr_name);
4704 			rtnl_lock();
4705 			ret = dev_ifsioc(net, &ifr, cmd);
4706 			rtnl_unlock();
4707 			if (!ret && copy_to_user(arg, &ifr,
4708 						 sizeof(struct ifreq)))
4709 				ret = -EFAULT;
4710 			return ret;
4711 		}
4712 		/* Take care of Wireless Extensions */
4713 		if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
4714 			return wext_handle_ioctl(net, &ifr, cmd, arg);
4715 		return -EINVAL;
4716 	}
4717 }
4718 
4719 
4720 /**
4721  *	dev_new_index	-	allocate an ifindex
4722  *	@net: the applicable net namespace
4723  *
4724  *	Returns a suitable unique value for a new device interface
4725  *	number.  The caller must hold the rtnl semaphore or the
4726  *	dev_base_lock to be sure it remains unique.
4727  */
4728 static int dev_new_index(struct net *net)
4729 {
4730 	static int ifindex;
4731 	for (;;) {
4732 		if (++ifindex <= 0)
4733 			ifindex = 1;
4734 		if (!__dev_get_by_index(net, ifindex))
4735 			return ifindex;
4736 	}
4737 }
4738 
4739 /* Delayed registration/unregisteration */
4740 static LIST_HEAD(net_todo_list);
4741 
4742 static void net_set_todo(struct net_device *dev)
4743 {
4744 	list_add_tail(&dev->todo_list, &net_todo_list);
4745 }
4746 
4747 static void rollback_registered_many(struct list_head *head)
4748 {
4749 	struct net_device *dev, *tmp;
4750 
4751 	BUG_ON(dev_boot_phase);
4752 	ASSERT_RTNL();
4753 
4754 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
4755 		/* Some devices call without registering
4756 		 * for initialization unwind. Remove those
4757 		 * devices and proceed with the remaining.
4758 		 */
4759 		if (dev->reg_state == NETREG_UNINITIALIZED) {
4760 			pr_debug("unregister_netdevice: device %s/%p never "
4761 				 "was registered\n", dev->name, dev);
4762 
4763 			WARN_ON(1);
4764 			list_del(&dev->unreg_list);
4765 			continue;
4766 		}
4767 
4768 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
4769 
4770 		/* If device is running, close it first. */
4771 		dev_close(dev);
4772 
4773 		/* And unlink it from device chain. */
4774 		unlist_netdevice(dev);
4775 
4776 		dev->reg_state = NETREG_UNREGISTERING;
4777 	}
4778 
4779 	synchronize_net();
4780 
4781 	list_for_each_entry(dev, head, unreg_list) {
4782 		/* Shutdown queueing discipline. */
4783 		dev_shutdown(dev);
4784 
4785 
4786 		/* Notify protocols, that we are about to destroy
4787 		   this device. They should clean all the things.
4788 		*/
4789 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
4790 
4791 		if (!dev->rtnl_link_ops ||
4792 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
4793 			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
4794 
4795 		/*
4796 		 *	Flush the unicast and multicast chains
4797 		 */
4798 		dev_uc_flush(dev);
4799 		dev_mc_flush(dev);
4800 
4801 		if (dev->netdev_ops->ndo_uninit)
4802 			dev->netdev_ops->ndo_uninit(dev);
4803 
4804 		/* Notifier chain MUST detach us from master device. */
4805 		WARN_ON(dev->master);
4806 
4807 		/* Remove entries from kobject tree */
4808 		netdev_unregister_kobject(dev);
4809 	}
4810 
4811 	/* Process any work delayed until the end of the batch */
4812 	dev = list_first_entry(head, struct net_device, unreg_list);
4813 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
4814 
4815 	synchronize_net();
4816 
4817 	list_for_each_entry(dev, head, unreg_list)
4818 		dev_put(dev);
4819 }
4820 
4821 static void rollback_registered(struct net_device *dev)
4822 {
4823 	LIST_HEAD(single);
4824 
4825 	list_add(&dev->unreg_list, &single);
4826 	rollback_registered_many(&single);
4827 }
4828 
4829 static void __netdev_init_queue_locks_one(struct net_device *dev,
4830 					  struct netdev_queue *dev_queue,
4831 					  void *_unused)
4832 {
4833 	spin_lock_init(&dev_queue->_xmit_lock);
4834 	netdev_set_xmit_lockdep_class(&dev_queue->_xmit_lock, dev->type);
4835 	dev_queue->xmit_lock_owner = -1;
4836 }
4837 
4838 static void netdev_init_queue_locks(struct net_device *dev)
4839 {
4840 	netdev_for_each_tx_queue(dev, __netdev_init_queue_locks_one, NULL);
4841 	__netdev_init_queue_locks_one(dev, &dev->rx_queue, NULL);
4842 }
4843 
4844 unsigned long netdev_fix_features(unsigned long features, const char *name)
4845 {
4846 	/* Fix illegal SG+CSUM combinations. */
4847 	if ((features & NETIF_F_SG) &&
4848 	    !(features & NETIF_F_ALL_CSUM)) {
4849 		if (name)
4850 			printk(KERN_NOTICE "%s: Dropping NETIF_F_SG since no "
4851 			       "checksum feature.\n", name);
4852 		features &= ~NETIF_F_SG;
4853 	}
4854 
4855 	/* TSO requires that SG is present as well. */
4856 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_SG)) {
4857 		if (name)
4858 			printk(KERN_NOTICE "%s: Dropping NETIF_F_TSO since no "
4859 			       "SG feature.\n", name);
4860 		features &= ~NETIF_F_TSO;
4861 	}
4862 
4863 	if (features & NETIF_F_UFO) {
4864 		if (!(features & NETIF_F_GEN_CSUM)) {
4865 			if (name)
4866 				printk(KERN_ERR "%s: Dropping NETIF_F_UFO "
4867 				       "since no NETIF_F_HW_CSUM feature.\n",
4868 				       name);
4869 			features &= ~NETIF_F_UFO;
4870 		}
4871 
4872 		if (!(features & NETIF_F_SG)) {
4873 			if (name)
4874 				printk(KERN_ERR "%s: Dropping NETIF_F_UFO "
4875 				       "since no NETIF_F_SG feature.\n", name);
4876 			features &= ~NETIF_F_UFO;
4877 		}
4878 	}
4879 
4880 	return features;
4881 }
4882 EXPORT_SYMBOL(netdev_fix_features);
4883 
4884 /**
4885  *	netif_stacked_transfer_operstate -	transfer operstate
4886  *	@rootdev: the root or lower level device to transfer state from
4887  *	@dev: the device to transfer operstate to
4888  *
4889  *	Transfer operational state from root to device. This is normally
4890  *	called when a stacking relationship exists between the root
4891  *	device and the device(a leaf device).
4892  */
4893 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
4894 					struct net_device *dev)
4895 {
4896 	if (rootdev->operstate == IF_OPER_DORMANT)
4897 		netif_dormant_on(dev);
4898 	else
4899 		netif_dormant_off(dev);
4900 
4901 	if (netif_carrier_ok(rootdev)) {
4902 		if (!netif_carrier_ok(dev))
4903 			netif_carrier_on(dev);
4904 	} else {
4905 		if (netif_carrier_ok(dev))
4906 			netif_carrier_off(dev);
4907 	}
4908 }
4909 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
4910 
4911 /**
4912  *	register_netdevice	- register a network device
4913  *	@dev: device to register
4914  *
4915  *	Take a completed network device structure and add it to the kernel
4916  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
4917  *	chain. 0 is returned on success. A negative errno code is returned
4918  *	on a failure to set up the device, or if the name is a duplicate.
4919  *
4920  *	Callers must hold the rtnl semaphore. You may want
4921  *	register_netdev() instead of this.
4922  *
4923  *	BUGS:
4924  *	The locking appears insufficient to guarantee two parallel registers
4925  *	will not get the same name.
4926  */
4927 
4928 int register_netdevice(struct net_device *dev)
4929 {
4930 	int ret;
4931 	struct net *net = dev_net(dev);
4932 
4933 	BUG_ON(dev_boot_phase);
4934 	ASSERT_RTNL();
4935 
4936 	might_sleep();
4937 
4938 	/* When net_device's are persistent, this will be fatal. */
4939 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
4940 	BUG_ON(!net);
4941 
4942 	spin_lock_init(&dev->addr_list_lock);
4943 	netdev_set_addr_lockdep_class(dev);
4944 	netdev_init_queue_locks(dev);
4945 
4946 	dev->iflink = -1;
4947 
4948 #ifdef CONFIG_RPS
4949 	if (!dev->num_rx_queues) {
4950 		/*
4951 		 * Allocate a single RX queue if driver never called
4952 		 * alloc_netdev_mq
4953 		 */
4954 
4955 		dev->_rx = kzalloc(sizeof(struct netdev_rx_queue), GFP_KERNEL);
4956 		if (!dev->_rx) {
4957 			ret = -ENOMEM;
4958 			goto out;
4959 		}
4960 
4961 		dev->_rx->first = dev->_rx;
4962 		atomic_set(&dev->_rx->count, 1);
4963 		dev->num_rx_queues = 1;
4964 	}
4965 #endif
4966 	/* Init, if this function is available */
4967 	if (dev->netdev_ops->ndo_init) {
4968 		ret = dev->netdev_ops->ndo_init(dev);
4969 		if (ret) {
4970 			if (ret > 0)
4971 				ret = -EIO;
4972 			goto out;
4973 		}
4974 	}
4975 
4976 	ret = dev_get_valid_name(dev, dev->name, 0);
4977 	if (ret)
4978 		goto err_uninit;
4979 
4980 	dev->ifindex = dev_new_index(net);
4981 	if (dev->iflink == -1)
4982 		dev->iflink = dev->ifindex;
4983 
4984 	/* Fix illegal checksum combinations */
4985 	if ((dev->features & NETIF_F_HW_CSUM) &&
4986 	    (dev->features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
4987 		printk(KERN_NOTICE "%s: mixed HW and IP checksum settings.\n",
4988 		       dev->name);
4989 		dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
4990 	}
4991 
4992 	if ((dev->features & NETIF_F_NO_CSUM) &&
4993 	    (dev->features & (NETIF_F_HW_CSUM|NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
4994 		printk(KERN_NOTICE "%s: mixed no checksumming and other settings.\n",
4995 		       dev->name);
4996 		dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM|NETIF_F_HW_CSUM);
4997 	}
4998 
4999 	dev->features = netdev_fix_features(dev->features, dev->name);
5000 
5001 	/* Enable software GSO if SG is supported. */
5002 	if (dev->features & NETIF_F_SG)
5003 		dev->features |= NETIF_F_GSO;
5004 
5005 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5006 	ret = notifier_to_errno(ret);
5007 	if (ret)
5008 		goto err_uninit;
5009 
5010 	ret = netdev_register_kobject(dev);
5011 	if (ret)
5012 		goto err_uninit;
5013 	dev->reg_state = NETREG_REGISTERED;
5014 
5015 	/*
5016 	 *	Default initial state at registry is that the
5017 	 *	device is present.
5018 	 */
5019 
5020 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5021 
5022 	dev_init_scheduler(dev);
5023 	dev_hold(dev);
5024 	list_netdevice(dev);
5025 
5026 	/* Notify protocols, that a new device appeared. */
5027 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5028 	ret = notifier_to_errno(ret);
5029 	if (ret) {
5030 		rollback_registered(dev);
5031 		dev->reg_state = NETREG_UNREGISTERED;
5032 	}
5033 	/*
5034 	 *	Prevent userspace races by waiting until the network
5035 	 *	device is fully setup before sending notifications.
5036 	 */
5037 	if (!dev->rtnl_link_ops ||
5038 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5039 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5040 
5041 out:
5042 	return ret;
5043 
5044 err_uninit:
5045 	if (dev->netdev_ops->ndo_uninit)
5046 		dev->netdev_ops->ndo_uninit(dev);
5047 	goto out;
5048 }
5049 EXPORT_SYMBOL(register_netdevice);
5050 
5051 /**
5052  *	init_dummy_netdev	- init a dummy network device for NAPI
5053  *	@dev: device to init
5054  *
5055  *	This takes a network device structure and initialize the minimum
5056  *	amount of fields so it can be used to schedule NAPI polls without
5057  *	registering a full blown interface. This is to be used by drivers
5058  *	that need to tie several hardware interfaces to a single NAPI
5059  *	poll scheduler due to HW limitations.
5060  */
5061 int init_dummy_netdev(struct net_device *dev)
5062 {
5063 	/* Clear everything. Note we don't initialize spinlocks
5064 	 * are they aren't supposed to be taken by any of the
5065 	 * NAPI code and this dummy netdev is supposed to be
5066 	 * only ever used for NAPI polls
5067 	 */
5068 	memset(dev, 0, sizeof(struct net_device));
5069 
5070 	/* make sure we BUG if trying to hit standard
5071 	 * register/unregister code path
5072 	 */
5073 	dev->reg_state = NETREG_DUMMY;
5074 
5075 	/* initialize the ref count */
5076 	atomic_set(&dev->refcnt, 1);
5077 
5078 	/* NAPI wants this */
5079 	INIT_LIST_HEAD(&dev->napi_list);
5080 
5081 	/* a dummy interface is started by default */
5082 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5083 	set_bit(__LINK_STATE_START, &dev->state);
5084 
5085 	return 0;
5086 }
5087 EXPORT_SYMBOL_GPL(init_dummy_netdev);
5088 
5089 
5090 /**
5091  *	register_netdev	- register a network device
5092  *	@dev: device to register
5093  *
5094  *	Take a completed network device structure and add it to the kernel
5095  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5096  *	chain. 0 is returned on success. A negative errno code is returned
5097  *	on a failure to set up the device, or if the name is a duplicate.
5098  *
5099  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
5100  *	and expands the device name if you passed a format string to
5101  *	alloc_netdev.
5102  */
5103 int register_netdev(struct net_device *dev)
5104 {
5105 	int err;
5106 
5107 	rtnl_lock();
5108 
5109 	/*
5110 	 * If the name is a format string the caller wants us to do a
5111 	 * name allocation.
5112 	 */
5113 	if (strchr(dev->name, '%')) {
5114 		err = dev_alloc_name(dev, dev->name);
5115 		if (err < 0)
5116 			goto out;
5117 	}
5118 
5119 	err = register_netdevice(dev);
5120 out:
5121 	rtnl_unlock();
5122 	return err;
5123 }
5124 EXPORT_SYMBOL(register_netdev);
5125 
5126 /*
5127  * netdev_wait_allrefs - wait until all references are gone.
5128  *
5129  * This is called when unregistering network devices.
5130  *
5131  * Any protocol or device that holds a reference should register
5132  * for netdevice notification, and cleanup and put back the
5133  * reference if they receive an UNREGISTER event.
5134  * We can get stuck here if buggy protocols don't correctly
5135  * call dev_put.
5136  */
5137 static void netdev_wait_allrefs(struct net_device *dev)
5138 {
5139 	unsigned long rebroadcast_time, warning_time;
5140 
5141 	linkwatch_forget_dev(dev);
5142 
5143 	rebroadcast_time = warning_time = jiffies;
5144 	while (atomic_read(&dev->refcnt) != 0) {
5145 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5146 			rtnl_lock();
5147 
5148 			/* Rebroadcast unregister notification */
5149 			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5150 			/* don't resend NETDEV_UNREGISTER_BATCH, _BATCH users
5151 			 * should have already handle it the first time */
5152 
5153 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
5154 				     &dev->state)) {
5155 				/* We must not have linkwatch events
5156 				 * pending on unregister. If this
5157 				 * happens, we simply run the queue
5158 				 * unscheduled, resulting in a noop
5159 				 * for this device.
5160 				 */
5161 				linkwatch_run_queue();
5162 			}
5163 
5164 			__rtnl_unlock();
5165 
5166 			rebroadcast_time = jiffies;
5167 		}
5168 
5169 		msleep(250);
5170 
5171 		if (time_after(jiffies, warning_time + 10 * HZ)) {
5172 			printk(KERN_EMERG "unregister_netdevice: "
5173 			       "waiting for %s to become free. Usage "
5174 			       "count = %d\n",
5175 			       dev->name, atomic_read(&dev->refcnt));
5176 			warning_time = jiffies;
5177 		}
5178 	}
5179 }
5180 
5181 /* The sequence is:
5182  *
5183  *	rtnl_lock();
5184  *	...
5185  *	register_netdevice(x1);
5186  *	register_netdevice(x2);
5187  *	...
5188  *	unregister_netdevice(y1);
5189  *	unregister_netdevice(y2);
5190  *      ...
5191  *	rtnl_unlock();
5192  *	free_netdev(y1);
5193  *	free_netdev(y2);
5194  *
5195  * We are invoked by rtnl_unlock().
5196  * This allows us to deal with problems:
5197  * 1) We can delete sysfs objects which invoke hotplug
5198  *    without deadlocking with linkwatch via keventd.
5199  * 2) Since we run with the RTNL semaphore not held, we can sleep
5200  *    safely in order to wait for the netdev refcnt to drop to zero.
5201  *
5202  * We must not return until all unregister events added during
5203  * the interval the lock was held have been completed.
5204  */
5205 void netdev_run_todo(void)
5206 {
5207 	struct list_head list;
5208 
5209 	/* Snapshot list, allow later requests */
5210 	list_replace_init(&net_todo_list, &list);
5211 
5212 	__rtnl_unlock();
5213 
5214 	while (!list_empty(&list)) {
5215 		struct net_device *dev
5216 			= list_first_entry(&list, struct net_device, todo_list);
5217 		list_del(&dev->todo_list);
5218 
5219 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5220 			printk(KERN_ERR "network todo '%s' but state %d\n",
5221 			       dev->name, dev->reg_state);
5222 			dump_stack();
5223 			continue;
5224 		}
5225 
5226 		dev->reg_state = NETREG_UNREGISTERED;
5227 
5228 		on_each_cpu(flush_backlog, dev, 1);
5229 
5230 		netdev_wait_allrefs(dev);
5231 
5232 		/* paranoia */
5233 		BUG_ON(atomic_read(&dev->refcnt));
5234 		WARN_ON(dev->ip_ptr);
5235 		WARN_ON(dev->ip6_ptr);
5236 		WARN_ON(dev->dn_ptr);
5237 
5238 		if (dev->destructor)
5239 			dev->destructor(dev);
5240 
5241 		/* Free network device */
5242 		kobject_put(&dev->dev.kobj);
5243 	}
5244 }
5245 
5246 /**
5247  *	dev_txq_stats_fold - fold tx_queues stats
5248  *	@dev: device to get statistics from
5249  *	@stats: struct net_device_stats to hold results
5250  */
5251 void dev_txq_stats_fold(const struct net_device *dev,
5252 			struct net_device_stats *stats)
5253 {
5254 	unsigned long tx_bytes = 0, tx_packets = 0, tx_dropped = 0;
5255 	unsigned int i;
5256 	struct netdev_queue *txq;
5257 
5258 	for (i = 0; i < dev->num_tx_queues; i++) {
5259 		txq = netdev_get_tx_queue(dev, i);
5260 		tx_bytes   += txq->tx_bytes;
5261 		tx_packets += txq->tx_packets;
5262 		tx_dropped += txq->tx_dropped;
5263 	}
5264 	if (tx_bytes || tx_packets || tx_dropped) {
5265 		stats->tx_bytes   = tx_bytes;
5266 		stats->tx_packets = tx_packets;
5267 		stats->tx_dropped = tx_dropped;
5268 	}
5269 }
5270 EXPORT_SYMBOL(dev_txq_stats_fold);
5271 
5272 /**
5273  *	dev_get_stats	- get network device statistics
5274  *	@dev: device to get statistics from
5275  *
5276  *	Get network statistics from device. The device driver may provide
5277  *	its own method by setting dev->netdev_ops->get_stats; otherwise
5278  *	the internal statistics structure is used.
5279  */
5280 const struct net_device_stats *dev_get_stats(struct net_device *dev)
5281 {
5282 	const struct net_device_ops *ops = dev->netdev_ops;
5283 
5284 	if (ops->ndo_get_stats)
5285 		return ops->ndo_get_stats(dev);
5286 
5287 	dev_txq_stats_fold(dev, &dev->stats);
5288 	return &dev->stats;
5289 }
5290 EXPORT_SYMBOL(dev_get_stats);
5291 
5292 static void netdev_init_one_queue(struct net_device *dev,
5293 				  struct netdev_queue *queue,
5294 				  void *_unused)
5295 {
5296 	queue->dev = dev;
5297 }
5298 
5299 static void netdev_init_queues(struct net_device *dev)
5300 {
5301 	netdev_init_one_queue(dev, &dev->rx_queue, NULL);
5302 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5303 	spin_lock_init(&dev->tx_global_lock);
5304 }
5305 
5306 /**
5307  *	alloc_netdev_mq - allocate network device
5308  *	@sizeof_priv:	size of private data to allocate space for
5309  *	@name:		device name format string
5310  *	@setup:		callback to initialize device
5311  *	@queue_count:	the number of subqueues to allocate
5312  *
5313  *	Allocates a struct net_device with private data area for driver use
5314  *	and performs basic initialization.  Also allocates subquue structs
5315  *	for each queue on the device at the end of the netdevice.
5316  */
5317 struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
5318 		void (*setup)(struct net_device *), unsigned int queue_count)
5319 {
5320 	struct netdev_queue *tx;
5321 	struct net_device *dev;
5322 	size_t alloc_size;
5323 	struct net_device *p;
5324 #ifdef CONFIG_RPS
5325 	struct netdev_rx_queue *rx;
5326 	int i;
5327 #endif
5328 
5329 	BUG_ON(strlen(name) >= sizeof(dev->name));
5330 
5331 	alloc_size = sizeof(struct net_device);
5332 	if (sizeof_priv) {
5333 		/* ensure 32-byte alignment of private area */
5334 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5335 		alloc_size += sizeof_priv;
5336 	}
5337 	/* ensure 32-byte alignment of whole construct */
5338 	alloc_size += NETDEV_ALIGN - 1;
5339 
5340 	p = kzalloc(alloc_size, GFP_KERNEL);
5341 	if (!p) {
5342 		printk(KERN_ERR "alloc_netdev: Unable to allocate device.\n");
5343 		return NULL;
5344 	}
5345 
5346 	tx = kcalloc(queue_count, sizeof(struct netdev_queue), GFP_KERNEL);
5347 	if (!tx) {
5348 		printk(KERN_ERR "alloc_netdev: Unable to allocate "
5349 		       "tx qdiscs.\n");
5350 		goto free_p;
5351 	}
5352 
5353 #ifdef CONFIG_RPS
5354 	rx = kcalloc(queue_count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5355 	if (!rx) {
5356 		printk(KERN_ERR "alloc_netdev: Unable to allocate "
5357 		       "rx queues.\n");
5358 		goto free_tx;
5359 	}
5360 
5361 	atomic_set(&rx->count, queue_count);
5362 
5363 	/*
5364 	 * Set a pointer to first element in the array which holds the
5365 	 * reference count.
5366 	 */
5367 	for (i = 0; i < queue_count; i++)
5368 		rx[i].first = rx;
5369 #endif
5370 
5371 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
5372 	dev->padded = (char *)dev - (char *)p;
5373 
5374 	if (dev_addr_init(dev))
5375 		goto free_rx;
5376 
5377 	dev_mc_init(dev);
5378 	dev_uc_init(dev);
5379 
5380 	dev_net_set(dev, &init_net);
5381 
5382 	dev->_tx = tx;
5383 	dev->num_tx_queues = queue_count;
5384 	dev->real_num_tx_queues = queue_count;
5385 
5386 #ifdef CONFIG_RPS
5387 	dev->_rx = rx;
5388 	dev->num_rx_queues = queue_count;
5389 #endif
5390 
5391 	dev->gso_max_size = GSO_MAX_SIZE;
5392 
5393 	netdev_init_queues(dev);
5394 
5395 	INIT_LIST_HEAD(&dev->ethtool_ntuple_list.list);
5396 	dev->ethtool_ntuple_list.count = 0;
5397 	INIT_LIST_HEAD(&dev->napi_list);
5398 	INIT_LIST_HEAD(&dev->unreg_list);
5399 	INIT_LIST_HEAD(&dev->link_watch_list);
5400 	dev->priv_flags = IFF_XMIT_DST_RELEASE;
5401 	setup(dev);
5402 	strcpy(dev->name, name);
5403 	return dev;
5404 
5405 free_rx:
5406 #ifdef CONFIG_RPS
5407 	kfree(rx);
5408 free_tx:
5409 #endif
5410 	kfree(tx);
5411 free_p:
5412 	kfree(p);
5413 	return NULL;
5414 }
5415 EXPORT_SYMBOL(alloc_netdev_mq);
5416 
5417 /**
5418  *	free_netdev - free network device
5419  *	@dev: device
5420  *
5421  *	This function does the last stage of destroying an allocated device
5422  * 	interface. The reference to the device object is released.
5423  *	If this is the last reference then it will be freed.
5424  */
5425 void free_netdev(struct net_device *dev)
5426 {
5427 	struct napi_struct *p, *n;
5428 
5429 	release_net(dev_net(dev));
5430 
5431 	kfree(dev->_tx);
5432 
5433 	/* Flush device addresses */
5434 	dev_addr_flush(dev);
5435 
5436 	/* Clear ethtool n-tuple list */
5437 	ethtool_ntuple_flush(dev);
5438 
5439 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
5440 		netif_napi_del(p);
5441 
5442 	/*  Compatibility with error handling in drivers */
5443 	if (dev->reg_state == NETREG_UNINITIALIZED) {
5444 		kfree((char *)dev - dev->padded);
5445 		return;
5446 	}
5447 
5448 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
5449 	dev->reg_state = NETREG_RELEASED;
5450 
5451 	/* will free via device release */
5452 	put_device(&dev->dev);
5453 }
5454 EXPORT_SYMBOL(free_netdev);
5455 
5456 /**
5457  *	synchronize_net -  Synchronize with packet receive processing
5458  *
5459  *	Wait for packets currently being received to be done.
5460  *	Does not block later packets from starting.
5461  */
5462 void synchronize_net(void)
5463 {
5464 	might_sleep();
5465 	synchronize_rcu();
5466 }
5467 EXPORT_SYMBOL(synchronize_net);
5468 
5469 /**
5470  *	unregister_netdevice_queue - remove device from the kernel
5471  *	@dev: device
5472  *	@head: list
5473  *
5474  *	This function shuts down a device interface and removes it
5475  *	from the kernel tables.
5476  *	If head not NULL, device is queued to be unregistered later.
5477  *
5478  *	Callers must hold the rtnl semaphore.  You may want
5479  *	unregister_netdev() instead of this.
5480  */
5481 
5482 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
5483 {
5484 	ASSERT_RTNL();
5485 
5486 	if (head) {
5487 		list_move_tail(&dev->unreg_list, head);
5488 	} else {
5489 		rollback_registered(dev);
5490 		/* Finish processing unregister after unlock */
5491 		net_set_todo(dev);
5492 	}
5493 }
5494 EXPORT_SYMBOL(unregister_netdevice_queue);
5495 
5496 /**
5497  *	unregister_netdevice_many - unregister many devices
5498  *	@head: list of devices
5499  */
5500 void unregister_netdevice_many(struct list_head *head)
5501 {
5502 	struct net_device *dev;
5503 
5504 	if (!list_empty(head)) {
5505 		rollback_registered_many(head);
5506 		list_for_each_entry(dev, head, unreg_list)
5507 			net_set_todo(dev);
5508 	}
5509 }
5510 EXPORT_SYMBOL(unregister_netdevice_many);
5511 
5512 /**
5513  *	unregister_netdev - remove device from the kernel
5514  *	@dev: device
5515  *
5516  *	This function shuts down a device interface and removes it
5517  *	from the kernel tables.
5518  *
5519  *	This is just a wrapper for unregister_netdevice that takes
5520  *	the rtnl semaphore.  In general you want to use this and not
5521  *	unregister_netdevice.
5522  */
5523 void unregister_netdev(struct net_device *dev)
5524 {
5525 	rtnl_lock();
5526 	unregister_netdevice(dev);
5527 	rtnl_unlock();
5528 }
5529 EXPORT_SYMBOL(unregister_netdev);
5530 
5531 /**
5532  *	dev_change_net_namespace - move device to different nethost namespace
5533  *	@dev: device
5534  *	@net: network namespace
5535  *	@pat: If not NULL name pattern to try if the current device name
5536  *	      is already taken in the destination network namespace.
5537  *
5538  *	This function shuts down a device interface and moves it
5539  *	to a new network namespace. On success 0 is returned, on
5540  *	a failure a netagive errno code is returned.
5541  *
5542  *	Callers must hold the rtnl semaphore.
5543  */
5544 
5545 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
5546 {
5547 	int err;
5548 
5549 	ASSERT_RTNL();
5550 
5551 	/* Don't allow namespace local devices to be moved. */
5552 	err = -EINVAL;
5553 	if (dev->features & NETIF_F_NETNS_LOCAL)
5554 		goto out;
5555 
5556 	/* Ensure the device has been registrered */
5557 	err = -EINVAL;
5558 	if (dev->reg_state != NETREG_REGISTERED)
5559 		goto out;
5560 
5561 	/* Get out if there is nothing todo */
5562 	err = 0;
5563 	if (net_eq(dev_net(dev), net))
5564 		goto out;
5565 
5566 	/* Pick the destination device name, and ensure
5567 	 * we can use it in the destination network namespace.
5568 	 */
5569 	err = -EEXIST;
5570 	if (__dev_get_by_name(net, dev->name)) {
5571 		/* We get here if we can't use the current device name */
5572 		if (!pat)
5573 			goto out;
5574 		if (dev_get_valid_name(dev, pat, 1))
5575 			goto out;
5576 	}
5577 
5578 	/*
5579 	 * And now a mini version of register_netdevice unregister_netdevice.
5580 	 */
5581 
5582 	/* If device is running close it first. */
5583 	dev_close(dev);
5584 
5585 	/* And unlink it from device chain */
5586 	err = -ENODEV;
5587 	unlist_netdevice(dev);
5588 
5589 	synchronize_net();
5590 
5591 	/* Shutdown queueing discipline. */
5592 	dev_shutdown(dev);
5593 
5594 	/* Notify protocols, that we are about to destroy
5595 	   this device. They should clean all the things.
5596 	*/
5597 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5598 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
5599 
5600 	/*
5601 	 *	Flush the unicast and multicast chains
5602 	 */
5603 	dev_uc_flush(dev);
5604 	dev_mc_flush(dev);
5605 
5606 	/* Actually switch the network namespace */
5607 	dev_net_set(dev, net);
5608 
5609 	/* If there is an ifindex conflict assign a new one */
5610 	if (__dev_get_by_index(net, dev->ifindex)) {
5611 		int iflink = (dev->iflink == dev->ifindex);
5612 		dev->ifindex = dev_new_index(net);
5613 		if (iflink)
5614 			dev->iflink = dev->ifindex;
5615 	}
5616 
5617 	/* Fixup kobjects */
5618 	err = device_rename(&dev->dev, dev->name);
5619 	WARN_ON(err);
5620 
5621 	/* Add the device back in the hashes */
5622 	list_netdevice(dev);
5623 
5624 	/* Notify protocols, that a new device appeared. */
5625 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
5626 
5627 	/*
5628 	 *	Prevent userspace races by waiting until the network
5629 	 *	device is fully setup before sending notifications.
5630 	 */
5631 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5632 
5633 	synchronize_net();
5634 	err = 0;
5635 out:
5636 	return err;
5637 }
5638 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
5639 
5640 static int dev_cpu_callback(struct notifier_block *nfb,
5641 			    unsigned long action,
5642 			    void *ocpu)
5643 {
5644 	struct sk_buff **list_skb;
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 	/* Append output queue from offline CPU. */
5666 	if (oldsd->output_queue) {
5667 		*sd->output_queue_tailp = oldsd->output_queue;
5668 		sd->output_queue_tailp = oldsd->output_queue_tailp;
5669 		oldsd->output_queue = NULL;
5670 		oldsd->output_queue_tailp = &oldsd->output_queue;
5671 	}
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->process_queue))) {
5678 		netif_rx(skb);
5679 		input_queue_head_incr(oldsd);
5680 	}
5681 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
5682 		netif_rx(skb);
5683 		input_queue_head_incr(oldsd);
5684 	}
5685 
5686 	return NOTIFY_OK;
5687 }
5688 
5689 
5690 /**
5691  *	netdev_increment_features - increment feature set by one
5692  *	@all: current feature set
5693  *	@one: new feature set
5694  *	@mask: mask feature set
5695  *
5696  *	Computes a new feature set after adding a device with feature set
5697  *	@one to the master device with current feature set @all.  Will not
5698  *	enable anything that is off in @mask. Returns the new feature set.
5699  */
5700 unsigned long netdev_increment_features(unsigned long all, unsigned long one,
5701 					unsigned long mask)
5702 {
5703 	/* If device needs checksumming, downgrade to it. */
5704 	if (all & NETIF_F_NO_CSUM && !(one & NETIF_F_NO_CSUM))
5705 		all ^= NETIF_F_NO_CSUM | (one & NETIF_F_ALL_CSUM);
5706 	else if (mask & NETIF_F_ALL_CSUM) {
5707 		/* If one device supports v4/v6 checksumming, set for all. */
5708 		if (one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM) &&
5709 		    !(all & NETIF_F_GEN_CSUM)) {
5710 			all &= ~NETIF_F_ALL_CSUM;
5711 			all |= one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
5712 		}
5713 
5714 		/* If one device supports hw checksumming, set for all. */
5715 		if (one & NETIF_F_GEN_CSUM && !(all & NETIF_F_GEN_CSUM)) {
5716 			all &= ~NETIF_F_ALL_CSUM;
5717 			all |= NETIF_F_HW_CSUM;
5718 		}
5719 	}
5720 
5721 	one |= NETIF_F_ALL_CSUM;
5722 
5723 	one |= all & NETIF_F_ONE_FOR_ALL;
5724 	all &= one | NETIF_F_LLTX | NETIF_F_GSO | NETIF_F_UFO;
5725 	all |= one & mask & NETIF_F_ONE_FOR_ALL;
5726 
5727 	return all;
5728 }
5729 EXPORT_SYMBOL(netdev_increment_features);
5730 
5731 static struct hlist_head *netdev_create_hash(void)
5732 {
5733 	int i;
5734 	struct hlist_head *hash;
5735 
5736 	hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
5737 	if (hash != NULL)
5738 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
5739 			INIT_HLIST_HEAD(&hash[i]);
5740 
5741 	return hash;
5742 }
5743 
5744 /* Initialize per network namespace state */
5745 static int __net_init netdev_init(struct net *net)
5746 {
5747 	INIT_LIST_HEAD(&net->dev_base_head);
5748 
5749 	net->dev_name_head = netdev_create_hash();
5750 	if (net->dev_name_head == NULL)
5751 		goto err_name;
5752 
5753 	net->dev_index_head = netdev_create_hash();
5754 	if (net->dev_index_head == NULL)
5755 		goto err_idx;
5756 
5757 	return 0;
5758 
5759 err_idx:
5760 	kfree(net->dev_name_head);
5761 err_name:
5762 	return -ENOMEM;
5763 }
5764 
5765 /**
5766  *	netdev_drivername - network driver for the device
5767  *	@dev: network device
5768  *	@buffer: buffer for resulting name
5769  *	@len: size of buffer
5770  *
5771  *	Determine network driver for device.
5772  */
5773 char *netdev_drivername(const struct net_device *dev, char *buffer, int len)
5774 {
5775 	const struct device_driver *driver;
5776 	const struct device *parent;
5777 
5778 	if (len <= 0 || !buffer)
5779 		return buffer;
5780 	buffer[0] = 0;
5781 
5782 	parent = dev->dev.parent;
5783 
5784 	if (!parent)
5785 		return buffer;
5786 
5787 	driver = parent->driver;
5788 	if (driver && driver->name)
5789 		strlcpy(buffer, driver->name, len);
5790 	return buffer;
5791 }
5792 
5793 static void __net_exit netdev_exit(struct net *net)
5794 {
5795 	kfree(net->dev_name_head);
5796 	kfree(net->dev_index_head);
5797 }
5798 
5799 static struct pernet_operations __net_initdata netdev_net_ops = {
5800 	.init = netdev_init,
5801 	.exit = netdev_exit,
5802 };
5803 
5804 static void __net_exit default_device_exit(struct net *net)
5805 {
5806 	struct net_device *dev, *aux;
5807 	/*
5808 	 * Push all migratable network devices back to the
5809 	 * initial network namespace
5810 	 */
5811 	rtnl_lock();
5812 	for_each_netdev_safe(net, dev, aux) {
5813 		int err;
5814 		char fb_name[IFNAMSIZ];
5815 
5816 		/* Ignore unmoveable devices (i.e. loopback) */
5817 		if (dev->features & NETIF_F_NETNS_LOCAL)
5818 			continue;
5819 
5820 		/* Leave virtual devices for the generic cleanup */
5821 		if (dev->rtnl_link_ops)
5822 			continue;
5823 
5824 		/* Push remaing network devices to init_net */
5825 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
5826 		err = dev_change_net_namespace(dev, &init_net, fb_name);
5827 		if (err) {
5828 			printk(KERN_EMERG "%s: failed to move %s to init_net: %d\n",
5829 				__func__, dev->name, err);
5830 			BUG();
5831 		}
5832 	}
5833 	rtnl_unlock();
5834 }
5835 
5836 static void __net_exit default_device_exit_batch(struct list_head *net_list)
5837 {
5838 	/* At exit all network devices most be removed from a network
5839 	 * namespace.  Do this in the reverse order of registeration.
5840 	 * Do this across as many network namespaces as possible to
5841 	 * improve batching efficiency.
5842 	 */
5843 	struct net_device *dev;
5844 	struct net *net;
5845 	LIST_HEAD(dev_kill_list);
5846 
5847 	rtnl_lock();
5848 	list_for_each_entry(net, net_list, exit_list) {
5849 		for_each_netdev_reverse(net, dev) {
5850 			if (dev->rtnl_link_ops)
5851 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
5852 			else
5853 				unregister_netdevice_queue(dev, &dev_kill_list);
5854 		}
5855 	}
5856 	unregister_netdevice_many(&dev_kill_list);
5857 	rtnl_unlock();
5858 }
5859 
5860 static struct pernet_operations __net_initdata default_device_ops = {
5861 	.exit = default_device_exit,
5862 	.exit_batch = default_device_exit_batch,
5863 };
5864 
5865 /*
5866  *	Initialize the DEV module. At boot time this walks the device list and
5867  *	unhooks any devices that fail to initialise (normally hardware not
5868  *	present) and leaves us with a valid list of present and active devices.
5869  *
5870  */
5871 
5872 /*
5873  *       This is called single threaded during boot, so no need
5874  *       to take the rtnl semaphore.
5875  */
5876 static int __init net_dev_init(void)
5877 {
5878 	int i, rc = -ENOMEM;
5879 
5880 	BUG_ON(!dev_boot_phase);
5881 
5882 	if (dev_proc_init())
5883 		goto out;
5884 
5885 	if (netdev_kobject_init())
5886 		goto out;
5887 
5888 	INIT_LIST_HEAD(&ptype_all);
5889 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
5890 		INIT_LIST_HEAD(&ptype_base[i]);
5891 
5892 	if (register_pernet_subsys(&netdev_net_ops))
5893 		goto out;
5894 
5895 	/*
5896 	 *	Initialise the packet receive queues.
5897 	 */
5898 
5899 	for_each_possible_cpu(i) {
5900 		struct softnet_data *sd = &per_cpu(softnet_data, i);
5901 
5902 		memset(sd, 0, sizeof(*sd));
5903 		skb_queue_head_init(&sd->input_pkt_queue);
5904 		skb_queue_head_init(&sd->process_queue);
5905 		sd->completion_queue = NULL;
5906 		INIT_LIST_HEAD(&sd->poll_list);
5907 		sd->output_queue = NULL;
5908 		sd->output_queue_tailp = &sd->output_queue;
5909 #ifdef CONFIG_RPS
5910 		sd->csd.func = rps_trigger_softirq;
5911 		sd->csd.info = sd;
5912 		sd->csd.flags = 0;
5913 		sd->cpu = i;
5914 #endif
5915 
5916 		sd->backlog.poll = process_backlog;
5917 		sd->backlog.weight = weight_p;
5918 		sd->backlog.gro_list = NULL;
5919 		sd->backlog.gro_count = 0;
5920 	}
5921 
5922 	dev_boot_phase = 0;
5923 
5924 	/* The loopback device is special if any other network devices
5925 	 * is present in a network namespace the loopback device must
5926 	 * be present. Since we now dynamically allocate and free the
5927 	 * loopback device ensure this invariant is maintained by
5928 	 * keeping the loopback device as the first device on the
5929 	 * list of network devices.  Ensuring the loopback devices
5930 	 * is the first device that appears and the last network device
5931 	 * that disappears.
5932 	 */
5933 	if (register_pernet_device(&loopback_net_ops))
5934 		goto out;
5935 
5936 	if (register_pernet_device(&default_device_ops))
5937 		goto out;
5938 
5939 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
5940 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
5941 
5942 	hotcpu_notifier(dev_cpu_callback, 0);
5943 	dst_init();
5944 	dev_mcast_init();
5945 	rc = 0;
5946 out:
5947 	return rc;
5948 }
5949 
5950 subsys_initcall(net_dev_init);
5951 
5952 static int __init initialize_hashrnd(void)
5953 {
5954 	get_random_bytes(&hashrnd, sizeof(hashrnd));
5955 	return 0;
5956 }
5957 
5958 late_initcall_sync(initialize_hashrnd);
5959 
5960