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v3.5.6
  1/*
  2 * net/core/dev_addr_lists.c - Functions for handling net device lists
  3 * Copyright (c) 2010 Jiri Pirko <jpirko@redhat.com>
  4 *
  5 * This file contains functions for working with unicast, multicast and device
  6 * addresses lists.
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License as published by
 10 * the Free Software Foundation; either version 2 of the License, or
 11 * (at your option) any later version.
 12 */
 13
 14#include <linux/netdevice.h>
 15#include <linux/rtnetlink.h>
 16#include <linux/export.h>
 17#include <linux/list.h>
 18#include <linux/proc_fs.h>
 19
 20/*
 21 * General list handling functions
 22 */
 23
 24static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
 25			       unsigned char *addr, int addr_len,
 26			       unsigned char addr_type, bool global)
 27{
 28	struct netdev_hw_addr *ha;
 29	int alloc_size;
 30
 31	alloc_size = sizeof(*ha);
 32	if (alloc_size < L1_CACHE_BYTES)
 33		alloc_size = L1_CACHE_BYTES;
 34	ha = kmalloc(alloc_size, GFP_ATOMIC);
 35	if (!ha)
 36		return -ENOMEM;
 37	memcpy(ha->addr, addr, addr_len);
 38	ha->type = addr_type;
 39	ha->refcount = 1;
 40	ha->global_use = global;
 41	ha->synced = false;
 42	list_add_tail_rcu(&ha->list, &list->list);
 43	list->count++;
 44
 45	return 0;
 46}
 47
 48static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
 49			    unsigned char *addr, int addr_len,
 50			    unsigned char addr_type, bool global)
 51{
 52	struct netdev_hw_addr *ha;
 
 53
 54	if (addr_len > MAX_ADDR_LEN)
 55		return -EINVAL;
 56
 57	list_for_each_entry(ha, &list->list, list) {
 58		if (!memcmp(ha->addr, addr, addr_len) &&
 59		    ha->type == addr_type) {
 60			if (global) {
 61				/* check if addr is already used as global */
 62				if (ha->global_use)
 63					return 0;
 64				else
 65					ha->global_use = true;
 66			}
 67			ha->refcount++;
 68			return 0;
 69		}
 70	}
 71
 72	return __hw_addr_create_ex(list, addr, addr_len, addr_type, global);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 73}
 74
 75static int __hw_addr_add(struct netdev_hw_addr_list *list, unsigned char *addr,
 76			 int addr_len, unsigned char addr_type)
 77{
 78	return __hw_addr_add_ex(list, addr, addr_len, addr_type, false);
 79}
 80
 81static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
 82			    unsigned char *addr, int addr_len,
 83			    unsigned char addr_type, bool global)
 84{
 85	struct netdev_hw_addr *ha;
 86
 87	list_for_each_entry(ha, &list->list, list) {
 88		if (!memcmp(ha->addr, addr, addr_len) &&
 89		    (ha->type == addr_type || !addr_type)) {
 90			if (global) {
 91				if (!ha->global_use)
 92					break;
 93				else
 94					ha->global_use = false;
 95			}
 96			if (--ha->refcount)
 97				return 0;
 98			list_del_rcu(&ha->list);
 99			kfree_rcu(ha, rcu_head);
100			list->count--;
101			return 0;
102		}
103	}
104	return -ENOENT;
105}
106
107static int __hw_addr_del(struct netdev_hw_addr_list *list, unsigned char *addr,
108			 int addr_len, unsigned char addr_type)
109{
110	return __hw_addr_del_ex(list, addr, addr_len, addr_type, false);
111}
112
113int __hw_addr_add_multiple(struct netdev_hw_addr_list *to_list,
114			   struct netdev_hw_addr_list *from_list,
115			   int addr_len, unsigned char addr_type)
116{
117	int err;
118	struct netdev_hw_addr *ha, *ha2;
119	unsigned char type;
120
121	list_for_each_entry(ha, &from_list->list, list) {
122		type = addr_type ? addr_type : ha->type;
123		err = __hw_addr_add(to_list, ha->addr, addr_len, type);
124		if (err)
125			goto unroll;
126	}
127	return 0;
128
129unroll:
130	list_for_each_entry(ha2, &from_list->list, list) {
131		if (ha2 == ha)
132			break;
133		type = addr_type ? addr_type : ha2->type;
134		__hw_addr_del(to_list, ha2->addr, addr_len, type);
135	}
136	return err;
137}
138EXPORT_SYMBOL(__hw_addr_add_multiple);
139
140void __hw_addr_del_multiple(struct netdev_hw_addr_list *to_list,
141			    struct netdev_hw_addr_list *from_list,
142			    int addr_len, unsigned char addr_type)
143{
144	struct netdev_hw_addr *ha;
145	unsigned char type;
146
147	list_for_each_entry(ha, &from_list->list, list) {
148		type = addr_type ? addr_type : ha->type;
149		__hw_addr_del(to_list, ha->addr, addr_len, type);
150	}
151}
152EXPORT_SYMBOL(__hw_addr_del_multiple);
153
154int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
155		   struct netdev_hw_addr_list *from_list,
156		   int addr_len)
157{
158	int err = 0;
159	struct netdev_hw_addr *ha, *tmp;
160
161	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
162		if (!ha->synced) {
163			err = __hw_addr_add(to_list, ha->addr,
164					    addr_len, ha->type);
165			if (err)
166				break;
167			ha->synced = true;
168			ha->refcount++;
169		} else if (ha->refcount == 1) {
170			__hw_addr_del(to_list, ha->addr, addr_len, ha->type);
171			__hw_addr_del(from_list, ha->addr, addr_len, ha->type);
172		}
173	}
174	return err;
175}
176EXPORT_SYMBOL(__hw_addr_sync);
177
178void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
179		      struct netdev_hw_addr_list *from_list,
180		      int addr_len)
181{
182	struct netdev_hw_addr *ha, *tmp;
183
184	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
185		if (ha->synced) {
186			__hw_addr_del(to_list, ha->addr,
187				      addr_len, ha->type);
188			ha->synced = false;
189			__hw_addr_del(from_list, ha->addr,
190				      addr_len, ha->type);
191		}
192	}
193}
194EXPORT_SYMBOL(__hw_addr_unsync);
195
196void __hw_addr_flush(struct netdev_hw_addr_list *list)
197{
198	struct netdev_hw_addr *ha, *tmp;
199
200	list_for_each_entry_safe(ha, tmp, &list->list, list) {
201		list_del_rcu(&ha->list);
202		kfree_rcu(ha, rcu_head);
203	}
204	list->count = 0;
205}
206EXPORT_SYMBOL(__hw_addr_flush);
207
208void __hw_addr_init(struct netdev_hw_addr_list *list)
209{
210	INIT_LIST_HEAD(&list->list);
211	list->count = 0;
212}
213EXPORT_SYMBOL(__hw_addr_init);
214
215/*
216 * Device addresses handling functions
217 */
218
219/**
220 *	dev_addr_flush - Flush device address list
221 *	@dev: device
222 *
223 *	Flush device address list and reset ->dev_addr.
224 *
225 *	The caller must hold the rtnl_mutex.
226 */
227void dev_addr_flush(struct net_device *dev)
228{
229	/* rtnl_mutex must be held here */
230
231	__hw_addr_flush(&dev->dev_addrs);
232	dev->dev_addr = NULL;
233}
234EXPORT_SYMBOL(dev_addr_flush);
235
236/**
237 *	dev_addr_init - Init device address list
238 *	@dev: device
239 *
240 *	Init device address list and create the first element,
241 *	used by ->dev_addr.
242 *
243 *	The caller must hold the rtnl_mutex.
244 */
245int dev_addr_init(struct net_device *dev)
246{
247	unsigned char addr[MAX_ADDR_LEN];
248	struct netdev_hw_addr *ha;
249	int err;
250
251	/* rtnl_mutex must be held here */
252
253	__hw_addr_init(&dev->dev_addrs);
254	memset(addr, 0, sizeof(addr));
255	err = __hw_addr_add(&dev->dev_addrs, addr, sizeof(addr),
256			    NETDEV_HW_ADDR_T_LAN);
257	if (!err) {
258		/*
259		 * Get the first (previously created) address from the list
260		 * and set dev_addr pointer to this location.
261		 */
262		ha = list_first_entry(&dev->dev_addrs.list,
263				      struct netdev_hw_addr, list);
264		dev->dev_addr = ha->addr;
265	}
266	return err;
267}
268EXPORT_SYMBOL(dev_addr_init);
269
270/**
271 *	dev_addr_add - Add a device address
272 *	@dev: device
273 *	@addr: address to add
274 *	@addr_type: address type
275 *
276 *	Add a device address to the device or increase the reference count if
277 *	it already exists.
278 *
279 *	The caller must hold the rtnl_mutex.
280 */
281int dev_addr_add(struct net_device *dev, unsigned char *addr,
282		 unsigned char addr_type)
283{
284	int err;
285
286	ASSERT_RTNL();
287
288	err = __hw_addr_add(&dev->dev_addrs, addr, dev->addr_len, addr_type);
289	if (!err)
290		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
291	return err;
292}
293EXPORT_SYMBOL(dev_addr_add);
294
295/**
296 *	dev_addr_del - Release a device address.
297 *	@dev: device
298 *	@addr: address to delete
299 *	@addr_type: address type
300 *
301 *	Release reference to a device address and remove it from the device
302 *	if the reference count drops to zero.
303 *
304 *	The caller must hold the rtnl_mutex.
305 */
306int dev_addr_del(struct net_device *dev, unsigned char *addr,
307		 unsigned char addr_type)
308{
309	int err;
310	struct netdev_hw_addr *ha;
311
312	ASSERT_RTNL();
313
314	/*
315	 * We can not remove the first address from the list because
316	 * dev->dev_addr points to that.
317	 */
318	ha = list_first_entry(&dev->dev_addrs.list,
319			      struct netdev_hw_addr, list);
320	if (ha->addr == dev->dev_addr && ha->refcount == 1)
321		return -ENOENT;
322
323	err = __hw_addr_del(&dev->dev_addrs, addr, dev->addr_len,
324			    addr_type);
325	if (!err)
326		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
327	return err;
328}
329EXPORT_SYMBOL(dev_addr_del);
330
331/**
332 *	dev_addr_add_multiple - Add device addresses from another device
333 *	@to_dev: device to which addresses will be added
334 *	@from_dev: device from which addresses will be added
335 *	@addr_type: address type - 0 means type will be used from from_dev
336 *
337 *	Add device addresses of the one device to another.
338 **
339 *	The caller must hold the rtnl_mutex.
340 */
341int dev_addr_add_multiple(struct net_device *to_dev,
342			  struct net_device *from_dev,
343			  unsigned char addr_type)
344{
345	int err;
346
347	ASSERT_RTNL();
348
349	if (from_dev->addr_len != to_dev->addr_len)
350		return -EINVAL;
351	err = __hw_addr_add_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
352				     to_dev->addr_len, addr_type);
353	if (!err)
354		call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
355	return err;
356}
357EXPORT_SYMBOL(dev_addr_add_multiple);
358
359/**
360 *	dev_addr_del_multiple - Delete device addresses by another device
361 *	@to_dev: device where the addresses will be deleted
362 *	@from_dev: device supplying the addresses to be deleted
363 *	@addr_type: address type - 0 means type will be used from from_dev
364 *
365 *	Deletes addresses in to device by the list of addresses in from device.
366 *
367 *	The caller must hold the rtnl_mutex.
368 */
369int dev_addr_del_multiple(struct net_device *to_dev,
370			  struct net_device *from_dev,
371			  unsigned char addr_type)
372{
373	ASSERT_RTNL();
374
375	if (from_dev->addr_len != to_dev->addr_len)
376		return -EINVAL;
377	__hw_addr_del_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
378			       to_dev->addr_len, addr_type);
379	call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
380	return 0;
381}
382EXPORT_SYMBOL(dev_addr_del_multiple);
383
384/*
385 * Unicast list handling functions
386 */
387
388/**
389 *	dev_uc_add_excl - Add a global secondary unicast address
390 *	@dev: device
391 *	@addr: address to add
392 */
393int dev_uc_add_excl(struct net_device *dev, unsigned char *addr)
394{
395	struct netdev_hw_addr *ha;
396	int err;
397
398	netif_addr_lock_bh(dev);
399	list_for_each_entry(ha, &dev->uc.list, list) {
400		if (!memcmp(ha->addr, addr, dev->addr_len) &&
401		    ha->type == NETDEV_HW_ADDR_T_UNICAST) {
402			err = -EEXIST;
403			goto out;
404		}
405	}
406	err = __hw_addr_create_ex(&dev->uc, addr, dev->addr_len,
407				  NETDEV_HW_ADDR_T_UNICAST, true);
408	if (!err)
409		__dev_set_rx_mode(dev);
410out:
411	netif_addr_unlock_bh(dev);
412	return err;
413}
414EXPORT_SYMBOL(dev_uc_add_excl);
415
416/**
417 *	dev_uc_add - Add a secondary unicast address
418 *	@dev: device
419 *	@addr: address to add
420 *
421 *	Add a secondary unicast address to the device or increase
422 *	the reference count if it already exists.
423 */
424int dev_uc_add(struct net_device *dev, unsigned char *addr)
425{
426	int err;
427
428	netif_addr_lock_bh(dev);
429	err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
430			    NETDEV_HW_ADDR_T_UNICAST);
431	if (!err)
432		__dev_set_rx_mode(dev);
433	netif_addr_unlock_bh(dev);
434	return err;
435}
436EXPORT_SYMBOL(dev_uc_add);
437
438/**
439 *	dev_uc_del - Release secondary unicast address.
440 *	@dev: device
441 *	@addr: address to delete
442 *
443 *	Release reference to a secondary unicast address and remove it
444 *	from the device if the reference count drops to zero.
445 */
446int dev_uc_del(struct net_device *dev, unsigned char *addr)
447{
448	int err;
449
450	netif_addr_lock_bh(dev);
451	err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
452			    NETDEV_HW_ADDR_T_UNICAST);
453	if (!err)
454		__dev_set_rx_mode(dev);
455	netif_addr_unlock_bh(dev);
456	return err;
457}
458EXPORT_SYMBOL(dev_uc_del);
459
460/**
461 *	dev_uc_sync - Synchronize device's unicast list to another device
462 *	@to: destination device
463 *	@from: source device
464 *
465 *	Add newly added addresses to the destination device and release
466 *	addresses that have no users left. The source device must be
467 *	locked by netif_addr_lock_bh.
468 *
469 *	This function is intended to be called from the dev->set_rx_mode
470 *	function of layered software devices.
471 */
472int dev_uc_sync(struct net_device *to, struct net_device *from)
473{
474	int err = 0;
475
476	if (to->addr_len != from->addr_len)
477		return -EINVAL;
478
479	netif_addr_lock_nested(to);
480	err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
481	if (!err)
482		__dev_set_rx_mode(to);
483	netif_addr_unlock(to);
484	return err;
485}
486EXPORT_SYMBOL(dev_uc_sync);
487
488/**
489 *	dev_uc_unsync - Remove synchronized addresses from the destination device
490 *	@to: destination device
491 *	@from: source device
492 *
493 *	Remove all addresses that were added to the destination device by
494 *	dev_uc_sync(). This function is intended to be called from the
495 *	dev->stop function of layered software devices.
496 */
497void dev_uc_unsync(struct net_device *to, struct net_device *from)
498{
499	if (to->addr_len != from->addr_len)
500		return;
501
502	netif_addr_lock_bh(from);
503	netif_addr_lock_nested(to);
504	__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
505	__dev_set_rx_mode(to);
506	netif_addr_unlock(to);
507	netif_addr_unlock_bh(from);
508}
509EXPORT_SYMBOL(dev_uc_unsync);
510
511/**
512 *	dev_uc_flush - Flush unicast addresses
513 *	@dev: device
514 *
515 *	Flush unicast addresses.
516 */
517void dev_uc_flush(struct net_device *dev)
518{
519	netif_addr_lock_bh(dev);
520	__hw_addr_flush(&dev->uc);
521	netif_addr_unlock_bh(dev);
522}
523EXPORT_SYMBOL(dev_uc_flush);
524
525/**
526 *	dev_uc_flush - Init unicast address list
527 *	@dev: device
528 *
529 *	Init unicast address list.
530 */
531void dev_uc_init(struct net_device *dev)
532{
533	__hw_addr_init(&dev->uc);
534}
535EXPORT_SYMBOL(dev_uc_init);
536
537/*
538 * Multicast list handling functions
539 */
540
541/**
542 *	dev_mc_add_excl - Add a global secondary multicast address
543 *	@dev: device
544 *	@addr: address to add
545 */
546int dev_mc_add_excl(struct net_device *dev, unsigned char *addr)
547{
548	struct netdev_hw_addr *ha;
549	int err;
550
551	netif_addr_lock_bh(dev);
552	list_for_each_entry(ha, &dev->mc.list, list) {
553		if (!memcmp(ha->addr, addr, dev->addr_len) &&
554		    ha->type == NETDEV_HW_ADDR_T_MULTICAST) {
555			err = -EEXIST;
556			goto out;
557		}
558	}
559	err = __hw_addr_create_ex(&dev->mc, addr, dev->addr_len,
560				  NETDEV_HW_ADDR_T_MULTICAST, true);
561	if (!err)
562		__dev_set_rx_mode(dev);
563out:
564	netif_addr_unlock_bh(dev);
565	return err;
566}
567EXPORT_SYMBOL(dev_mc_add_excl);
568
569static int __dev_mc_add(struct net_device *dev, unsigned char *addr,
570			bool global)
571{
572	int err;
573
574	netif_addr_lock_bh(dev);
575	err = __hw_addr_add_ex(&dev->mc, addr, dev->addr_len,
576			       NETDEV_HW_ADDR_T_MULTICAST, global);
577	if (!err)
578		__dev_set_rx_mode(dev);
579	netif_addr_unlock_bh(dev);
580	return err;
581}
582/**
583 *	dev_mc_add - Add a multicast address
584 *	@dev: device
585 *	@addr: address to add
586 *
587 *	Add a multicast address to the device or increase
588 *	the reference count if it already exists.
589 */
590int dev_mc_add(struct net_device *dev, unsigned char *addr)
591{
592	return __dev_mc_add(dev, addr, false);
593}
594EXPORT_SYMBOL(dev_mc_add);
595
596/**
597 *	dev_mc_add_global - Add a global multicast address
598 *	@dev: device
599 *	@addr: address to add
600 *
601 *	Add a global multicast address to the device.
602 */
603int dev_mc_add_global(struct net_device *dev, unsigned char *addr)
604{
605	return __dev_mc_add(dev, addr, true);
606}
607EXPORT_SYMBOL(dev_mc_add_global);
608
609static int __dev_mc_del(struct net_device *dev, unsigned char *addr,
610			bool global)
611{
612	int err;
613
614	netif_addr_lock_bh(dev);
615	err = __hw_addr_del_ex(&dev->mc, addr, dev->addr_len,
616			       NETDEV_HW_ADDR_T_MULTICAST, global);
617	if (!err)
618		__dev_set_rx_mode(dev);
619	netif_addr_unlock_bh(dev);
620	return err;
621}
622
623/**
624 *	dev_mc_del - Delete a multicast address.
625 *	@dev: device
626 *	@addr: address to delete
627 *
628 *	Release reference to a multicast address and remove it
629 *	from the device if the reference count drops to zero.
630 */
631int dev_mc_del(struct net_device *dev, unsigned char *addr)
632{
633	return __dev_mc_del(dev, addr, false);
634}
635EXPORT_SYMBOL(dev_mc_del);
636
637/**
638 *	dev_mc_del_global - Delete a global multicast address.
639 *	@dev: device
640 *	@addr: address to delete
641 *
642 *	Release reference to a multicast address and remove it
643 *	from the device if the reference count drops to zero.
644 */
645int dev_mc_del_global(struct net_device *dev, unsigned char *addr)
646{
647	return __dev_mc_del(dev, addr, true);
648}
649EXPORT_SYMBOL(dev_mc_del_global);
650
651/**
652 *	dev_mc_sync - Synchronize device's unicast list to another device
653 *	@to: destination device
654 *	@from: source device
655 *
656 *	Add newly added addresses to the destination device and release
657 *	addresses that have no users left. The source device must be
658 *	locked by netif_addr_lock_bh.
659 *
660 *	This function is intended to be called from the ndo_set_rx_mode
661 *	function of layered software devices.
662 */
663int dev_mc_sync(struct net_device *to, struct net_device *from)
664{
665	int err = 0;
666
667	if (to->addr_len != from->addr_len)
668		return -EINVAL;
669
670	netif_addr_lock_nested(to);
671	err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
672	if (!err)
673		__dev_set_rx_mode(to);
674	netif_addr_unlock(to);
675	return err;
676}
677EXPORT_SYMBOL(dev_mc_sync);
678
679/**
680 *	dev_mc_unsync - Remove synchronized addresses from the destination device
681 *	@to: destination device
682 *	@from: source device
683 *
684 *	Remove all addresses that were added to the destination device by
685 *	dev_mc_sync(). This function is intended to be called from the
686 *	dev->stop function of layered software devices.
687 */
688void dev_mc_unsync(struct net_device *to, struct net_device *from)
689{
690	if (to->addr_len != from->addr_len)
691		return;
692
693	netif_addr_lock_bh(from);
694	netif_addr_lock_nested(to);
695	__hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
696	__dev_set_rx_mode(to);
697	netif_addr_unlock(to);
698	netif_addr_unlock_bh(from);
699}
700EXPORT_SYMBOL(dev_mc_unsync);
701
702/**
703 *	dev_mc_flush - Flush multicast addresses
704 *	@dev: device
705 *
706 *	Flush multicast addresses.
707 */
708void dev_mc_flush(struct net_device *dev)
709{
710	netif_addr_lock_bh(dev);
711	__hw_addr_flush(&dev->mc);
712	netif_addr_unlock_bh(dev);
713}
714EXPORT_SYMBOL(dev_mc_flush);
715
716/**
717 *	dev_mc_flush - Init multicast address list
718 *	@dev: device
719 *
720 *	Init multicast address list.
721 */
722void dev_mc_init(struct net_device *dev)
723{
724	__hw_addr_init(&dev->mc);
725}
726EXPORT_SYMBOL(dev_mc_init);
727
728#ifdef CONFIG_PROC_FS
729#include <linux/seq_file.h>
730
731static int dev_mc_seq_show(struct seq_file *seq, void *v)
732{
733	struct netdev_hw_addr *ha;
734	struct net_device *dev = v;
735
736	if (v == SEQ_START_TOKEN)
737		return 0;
738
739	netif_addr_lock_bh(dev);
740	netdev_for_each_mc_addr(ha, dev) {
741		int i;
742
743		seq_printf(seq, "%-4d %-15s %-5d %-5d ", dev->ifindex,
744			   dev->name, ha->refcount, ha->global_use);
745
746		for (i = 0; i < dev->addr_len; i++)
747			seq_printf(seq, "%02x", ha->addr[i]);
748
749		seq_putc(seq, '\n');
750	}
751	netif_addr_unlock_bh(dev);
752	return 0;
753}
754
755static const struct seq_operations dev_mc_seq_ops = {
756	.start = dev_seq_start,
757	.next  = dev_seq_next,
758	.stop  = dev_seq_stop,
759	.show  = dev_mc_seq_show,
760};
761
762static int dev_mc_seq_open(struct inode *inode, struct file *file)
763{
764	return seq_open_net(inode, file, &dev_mc_seq_ops,
765			    sizeof(struct seq_net_private));
766}
767
768static const struct file_operations dev_mc_seq_fops = {
769	.owner	 = THIS_MODULE,
770	.open    = dev_mc_seq_open,
771	.read    = seq_read,
772	.llseek  = seq_lseek,
773	.release = seq_release_net,
774};
775
776#endif
777
778static int __net_init dev_mc_net_init(struct net *net)
779{
780	if (!proc_net_fops_create(net, "dev_mcast", 0, &dev_mc_seq_fops))
781		return -ENOMEM;
782	return 0;
783}
784
785static void __net_exit dev_mc_net_exit(struct net *net)
786{
787	proc_net_remove(net, "dev_mcast");
788}
789
790static struct pernet_operations __net_initdata dev_mc_net_ops = {
791	.init = dev_mc_net_init,
792	.exit = dev_mc_net_exit,
793};
794
795void __init dev_mcast_init(void)
796{
797	register_pernet_subsys(&dev_mc_net_ops);
798}
799
v3.1
  1/*
  2 * net/core/dev_addr_lists.c - Functions for handling net device lists
  3 * Copyright (c) 2010 Jiri Pirko <jpirko@redhat.com>
  4 *
  5 * This file contains functions for working with unicast, multicast and device
  6 * addresses lists.
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License as published by
 10 * the Free Software Foundation; either version 2 of the License, or
 11 * (at your option) any later version.
 12 */
 13
 14#include <linux/netdevice.h>
 15#include <linux/rtnetlink.h>
 
 16#include <linux/list.h>
 17#include <linux/proc_fs.h>
 18
 19/*
 20 * General list handling functions
 21 */
 22
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 23static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
 24			    unsigned char *addr, int addr_len,
 25			    unsigned char addr_type, bool global)
 26{
 27	struct netdev_hw_addr *ha;
 28	int alloc_size;
 29
 30	if (addr_len > MAX_ADDR_LEN)
 31		return -EINVAL;
 32
 33	list_for_each_entry(ha, &list->list, list) {
 34		if (!memcmp(ha->addr, addr, addr_len) &&
 35		    ha->type == addr_type) {
 36			if (global) {
 37				/* check if addr is already used as global */
 38				if (ha->global_use)
 39					return 0;
 40				else
 41					ha->global_use = true;
 42			}
 43			ha->refcount++;
 44			return 0;
 45		}
 46	}
 47
 48
 49	alloc_size = sizeof(*ha);
 50	if (alloc_size < L1_CACHE_BYTES)
 51		alloc_size = L1_CACHE_BYTES;
 52	ha = kmalloc(alloc_size, GFP_ATOMIC);
 53	if (!ha)
 54		return -ENOMEM;
 55	memcpy(ha->addr, addr, addr_len);
 56	ha->type = addr_type;
 57	ha->refcount = 1;
 58	ha->global_use = global;
 59	ha->synced = false;
 60	list_add_tail_rcu(&ha->list, &list->list);
 61	list->count++;
 62	return 0;
 63}
 64
 65static int __hw_addr_add(struct netdev_hw_addr_list *list, unsigned char *addr,
 66			 int addr_len, unsigned char addr_type)
 67{
 68	return __hw_addr_add_ex(list, addr, addr_len, addr_type, false);
 69}
 70
 71static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
 72			    unsigned char *addr, int addr_len,
 73			    unsigned char addr_type, bool global)
 74{
 75	struct netdev_hw_addr *ha;
 76
 77	list_for_each_entry(ha, &list->list, list) {
 78		if (!memcmp(ha->addr, addr, addr_len) &&
 79		    (ha->type == addr_type || !addr_type)) {
 80			if (global) {
 81				if (!ha->global_use)
 82					break;
 83				else
 84					ha->global_use = false;
 85			}
 86			if (--ha->refcount)
 87				return 0;
 88			list_del_rcu(&ha->list);
 89			kfree_rcu(ha, rcu_head);
 90			list->count--;
 91			return 0;
 92		}
 93	}
 94	return -ENOENT;
 95}
 96
 97static int __hw_addr_del(struct netdev_hw_addr_list *list, unsigned char *addr,
 98			 int addr_len, unsigned char addr_type)
 99{
100	return __hw_addr_del_ex(list, addr, addr_len, addr_type, false);
101}
102
103int __hw_addr_add_multiple(struct netdev_hw_addr_list *to_list,
104			   struct netdev_hw_addr_list *from_list,
105			   int addr_len, unsigned char addr_type)
106{
107	int err;
108	struct netdev_hw_addr *ha, *ha2;
109	unsigned char type;
110
111	list_for_each_entry(ha, &from_list->list, list) {
112		type = addr_type ? addr_type : ha->type;
113		err = __hw_addr_add(to_list, ha->addr, addr_len, type);
114		if (err)
115			goto unroll;
116	}
117	return 0;
118
119unroll:
120	list_for_each_entry(ha2, &from_list->list, list) {
121		if (ha2 == ha)
122			break;
123		type = addr_type ? addr_type : ha2->type;
124		__hw_addr_del(to_list, ha2->addr, addr_len, type);
125	}
126	return err;
127}
128EXPORT_SYMBOL(__hw_addr_add_multiple);
129
130void __hw_addr_del_multiple(struct netdev_hw_addr_list *to_list,
131			    struct netdev_hw_addr_list *from_list,
132			    int addr_len, unsigned char addr_type)
133{
134	struct netdev_hw_addr *ha;
135	unsigned char type;
136
137	list_for_each_entry(ha, &from_list->list, list) {
138		type = addr_type ? addr_type : ha->type;
139		__hw_addr_del(to_list, ha->addr, addr_len, type);
140	}
141}
142EXPORT_SYMBOL(__hw_addr_del_multiple);
143
144int __hw_addr_sync(struct netdev_hw_addr_list *to_list,
145		   struct netdev_hw_addr_list *from_list,
146		   int addr_len)
147{
148	int err = 0;
149	struct netdev_hw_addr *ha, *tmp;
150
151	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
152		if (!ha->synced) {
153			err = __hw_addr_add(to_list, ha->addr,
154					    addr_len, ha->type);
155			if (err)
156				break;
157			ha->synced = true;
158			ha->refcount++;
159		} else if (ha->refcount == 1) {
160			__hw_addr_del(to_list, ha->addr, addr_len, ha->type);
161			__hw_addr_del(from_list, ha->addr, addr_len, ha->type);
162		}
163	}
164	return err;
165}
166EXPORT_SYMBOL(__hw_addr_sync);
167
168void __hw_addr_unsync(struct netdev_hw_addr_list *to_list,
169		      struct netdev_hw_addr_list *from_list,
170		      int addr_len)
171{
172	struct netdev_hw_addr *ha, *tmp;
173
174	list_for_each_entry_safe(ha, tmp, &from_list->list, list) {
175		if (ha->synced) {
176			__hw_addr_del(to_list, ha->addr,
177				      addr_len, ha->type);
178			ha->synced = false;
179			__hw_addr_del(from_list, ha->addr,
180				      addr_len, ha->type);
181		}
182	}
183}
184EXPORT_SYMBOL(__hw_addr_unsync);
185
186void __hw_addr_flush(struct netdev_hw_addr_list *list)
187{
188	struct netdev_hw_addr *ha, *tmp;
189
190	list_for_each_entry_safe(ha, tmp, &list->list, list) {
191		list_del_rcu(&ha->list);
192		kfree_rcu(ha, rcu_head);
193	}
194	list->count = 0;
195}
196EXPORT_SYMBOL(__hw_addr_flush);
197
198void __hw_addr_init(struct netdev_hw_addr_list *list)
199{
200	INIT_LIST_HEAD(&list->list);
201	list->count = 0;
202}
203EXPORT_SYMBOL(__hw_addr_init);
204
205/*
206 * Device addresses handling functions
207 */
208
209/**
210 *	dev_addr_flush - Flush device address list
211 *	@dev: device
212 *
213 *	Flush device address list and reset ->dev_addr.
214 *
215 *	The caller must hold the rtnl_mutex.
216 */
217void dev_addr_flush(struct net_device *dev)
218{
219	/* rtnl_mutex must be held here */
220
221	__hw_addr_flush(&dev->dev_addrs);
222	dev->dev_addr = NULL;
223}
224EXPORT_SYMBOL(dev_addr_flush);
225
226/**
227 *	dev_addr_init - Init device address list
228 *	@dev: device
229 *
230 *	Init device address list and create the first element,
231 *	used by ->dev_addr.
232 *
233 *	The caller must hold the rtnl_mutex.
234 */
235int dev_addr_init(struct net_device *dev)
236{
237	unsigned char addr[MAX_ADDR_LEN];
238	struct netdev_hw_addr *ha;
239	int err;
240
241	/* rtnl_mutex must be held here */
242
243	__hw_addr_init(&dev->dev_addrs);
244	memset(addr, 0, sizeof(addr));
245	err = __hw_addr_add(&dev->dev_addrs, addr, sizeof(addr),
246			    NETDEV_HW_ADDR_T_LAN);
247	if (!err) {
248		/*
249		 * Get the first (previously created) address from the list
250		 * and set dev_addr pointer to this location.
251		 */
252		ha = list_first_entry(&dev->dev_addrs.list,
253				      struct netdev_hw_addr, list);
254		dev->dev_addr = ha->addr;
255	}
256	return err;
257}
258EXPORT_SYMBOL(dev_addr_init);
259
260/**
261 *	dev_addr_add - Add a device address
262 *	@dev: device
263 *	@addr: address to add
264 *	@addr_type: address type
265 *
266 *	Add a device address to the device or increase the reference count if
267 *	it already exists.
268 *
269 *	The caller must hold the rtnl_mutex.
270 */
271int dev_addr_add(struct net_device *dev, unsigned char *addr,
272		 unsigned char addr_type)
273{
274	int err;
275
276	ASSERT_RTNL();
277
278	err = __hw_addr_add(&dev->dev_addrs, addr, dev->addr_len, addr_type);
279	if (!err)
280		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
281	return err;
282}
283EXPORT_SYMBOL(dev_addr_add);
284
285/**
286 *	dev_addr_del - Release a device address.
287 *	@dev: device
288 *	@addr: address to delete
289 *	@addr_type: address type
290 *
291 *	Release reference to a device address and remove it from the device
292 *	if the reference count drops to zero.
293 *
294 *	The caller must hold the rtnl_mutex.
295 */
296int dev_addr_del(struct net_device *dev, unsigned char *addr,
297		 unsigned char addr_type)
298{
299	int err;
300	struct netdev_hw_addr *ha;
301
302	ASSERT_RTNL();
303
304	/*
305	 * We can not remove the first address from the list because
306	 * dev->dev_addr points to that.
307	 */
308	ha = list_first_entry(&dev->dev_addrs.list,
309			      struct netdev_hw_addr, list);
310	if (ha->addr == dev->dev_addr && ha->refcount == 1)
311		return -ENOENT;
312
313	err = __hw_addr_del(&dev->dev_addrs, addr, dev->addr_len,
314			    addr_type);
315	if (!err)
316		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
317	return err;
318}
319EXPORT_SYMBOL(dev_addr_del);
320
321/**
322 *	dev_addr_add_multiple - Add device addresses from another device
323 *	@to_dev: device to which addresses will be added
324 *	@from_dev: device from which addresses will be added
325 *	@addr_type: address type - 0 means type will be used from from_dev
326 *
327 *	Add device addresses of the one device to another.
328 **
329 *	The caller must hold the rtnl_mutex.
330 */
331int dev_addr_add_multiple(struct net_device *to_dev,
332			  struct net_device *from_dev,
333			  unsigned char addr_type)
334{
335	int err;
336
337	ASSERT_RTNL();
338
339	if (from_dev->addr_len != to_dev->addr_len)
340		return -EINVAL;
341	err = __hw_addr_add_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
342				     to_dev->addr_len, addr_type);
343	if (!err)
344		call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
345	return err;
346}
347EXPORT_SYMBOL(dev_addr_add_multiple);
348
349/**
350 *	dev_addr_del_multiple - Delete device addresses by another device
351 *	@to_dev: device where the addresses will be deleted
352 *	@from_dev: device supplying the addresses to be deleted
353 *	@addr_type: address type - 0 means type will be used from from_dev
354 *
355 *	Deletes addresses in to device by the list of addresses in from device.
356 *
357 *	The caller must hold the rtnl_mutex.
358 */
359int dev_addr_del_multiple(struct net_device *to_dev,
360			  struct net_device *from_dev,
361			  unsigned char addr_type)
362{
363	ASSERT_RTNL();
364
365	if (from_dev->addr_len != to_dev->addr_len)
366		return -EINVAL;
367	__hw_addr_del_multiple(&to_dev->dev_addrs, &from_dev->dev_addrs,
368			       to_dev->addr_len, addr_type);
369	call_netdevice_notifiers(NETDEV_CHANGEADDR, to_dev);
370	return 0;
371}
372EXPORT_SYMBOL(dev_addr_del_multiple);
373
374/*
375 * Unicast list handling functions
376 */
377
378/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
379 *	dev_uc_add - Add a secondary unicast address
380 *	@dev: device
381 *	@addr: address to add
382 *
383 *	Add a secondary unicast address to the device or increase
384 *	the reference count if it already exists.
385 */
386int dev_uc_add(struct net_device *dev, unsigned char *addr)
387{
388	int err;
389
390	netif_addr_lock_bh(dev);
391	err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
392			    NETDEV_HW_ADDR_T_UNICAST);
393	if (!err)
394		__dev_set_rx_mode(dev);
395	netif_addr_unlock_bh(dev);
396	return err;
397}
398EXPORT_SYMBOL(dev_uc_add);
399
400/**
401 *	dev_uc_del - Release secondary unicast address.
402 *	@dev: device
403 *	@addr: address to delete
404 *
405 *	Release reference to a secondary unicast address and remove it
406 *	from the device if the reference count drops to zero.
407 */
408int dev_uc_del(struct net_device *dev, unsigned char *addr)
409{
410	int err;
411
412	netif_addr_lock_bh(dev);
413	err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
414			    NETDEV_HW_ADDR_T_UNICAST);
415	if (!err)
416		__dev_set_rx_mode(dev);
417	netif_addr_unlock_bh(dev);
418	return err;
419}
420EXPORT_SYMBOL(dev_uc_del);
421
422/**
423 *	dev_uc_sync - Synchronize device's unicast list to another device
424 *	@to: destination device
425 *	@from: source device
426 *
427 *	Add newly added addresses to the destination device and release
428 *	addresses that have no users left. The source device must be
429 *	locked by netif_tx_lock_bh.
430 *
431 *	This function is intended to be called from the dev->set_rx_mode
432 *	function of layered software devices.
433 */
434int dev_uc_sync(struct net_device *to, struct net_device *from)
435{
436	int err = 0;
437
438	if (to->addr_len != from->addr_len)
439		return -EINVAL;
440
441	netif_addr_lock_bh(to);
442	err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
443	if (!err)
444		__dev_set_rx_mode(to);
445	netif_addr_unlock_bh(to);
446	return err;
447}
448EXPORT_SYMBOL(dev_uc_sync);
449
450/**
451 *	dev_uc_unsync - Remove synchronized addresses from the destination device
452 *	@to: destination device
453 *	@from: source device
454 *
455 *	Remove all addresses that were added to the destination device by
456 *	dev_uc_sync(). This function is intended to be called from the
457 *	dev->stop function of layered software devices.
458 */
459void dev_uc_unsync(struct net_device *to, struct net_device *from)
460{
461	if (to->addr_len != from->addr_len)
462		return;
463
464	netif_addr_lock_bh(from);
465	netif_addr_lock(to);
466	__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
467	__dev_set_rx_mode(to);
468	netif_addr_unlock(to);
469	netif_addr_unlock_bh(from);
470}
471EXPORT_SYMBOL(dev_uc_unsync);
472
473/**
474 *	dev_uc_flush - Flush unicast addresses
475 *	@dev: device
476 *
477 *	Flush unicast addresses.
478 */
479void dev_uc_flush(struct net_device *dev)
480{
481	netif_addr_lock_bh(dev);
482	__hw_addr_flush(&dev->uc);
483	netif_addr_unlock_bh(dev);
484}
485EXPORT_SYMBOL(dev_uc_flush);
486
487/**
488 *	dev_uc_flush - Init unicast address list
489 *	@dev: device
490 *
491 *	Init unicast address list.
492 */
493void dev_uc_init(struct net_device *dev)
494{
495	__hw_addr_init(&dev->uc);
496}
497EXPORT_SYMBOL(dev_uc_init);
498
499/*
500 * Multicast list handling functions
501 */
502
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
503static int __dev_mc_add(struct net_device *dev, unsigned char *addr,
504			bool global)
505{
506	int err;
507
508	netif_addr_lock_bh(dev);
509	err = __hw_addr_add_ex(&dev->mc, addr, dev->addr_len,
510			       NETDEV_HW_ADDR_T_MULTICAST, global);
511	if (!err)
512		__dev_set_rx_mode(dev);
513	netif_addr_unlock_bh(dev);
514	return err;
515}
516/**
517 *	dev_mc_add - Add a multicast address
518 *	@dev: device
519 *	@addr: address to add
520 *
521 *	Add a multicast address to the device or increase
522 *	the reference count if it already exists.
523 */
524int dev_mc_add(struct net_device *dev, unsigned char *addr)
525{
526	return __dev_mc_add(dev, addr, false);
527}
528EXPORT_SYMBOL(dev_mc_add);
529
530/**
531 *	dev_mc_add_global - Add a global multicast address
532 *	@dev: device
533 *	@addr: address to add
534 *
535 *	Add a global multicast address to the device.
536 */
537int dev_mc_add_global(struct net_device *dev, unsigned char *addr)
538{
539	return __dev_mc_add(dev, addr, true);
540}
541EXPORT_SYMBOL(dev_mc_add_global);
542
543static int __dev_mc_del(struct net_device *dev, unsigned char *addr,
544			bool global)
545{
546	int err;
547
548	netif_addr_lock_bh(dev);
549	err = __hw_addr_del_ex(&dev->mc, addr, dev->addr_len,
550			       NETDEV_HW_ADDR_T_MULTICAST, global);
551	if (!err)
552		__dev_set_rx_mode(dev);
553	netif_addr_unlock_bh(dev);
554	return err;
555}
556
557/**
558 *	dev_mc_del - Delete a multicast address.
559 *	@dev: device
560 *	@addr: address to delete
561 *
562 *	Release reference to a multicast address and remove it
563 *	from the device if the reference count drops to zero.
564 */
565int dev_mc_del(struct net_device *dev, unsigned char *addr)
566{
567	return __dev_mc_del(dev, addr, false);
568}
569EXPORT_SYMBOL(dev_mc_del);
570
571/**
572 *	dev_mc_del_global - Delete a global multicast address.
573 *	@dev: device
574 *	@addr: address to delete
575 *
576 *	Release reference to a multicast address and remove it
577 *	from the device if the reference count drops to zero.
578 */
579int dev_mc_del_global(struct net_device *dev, unsigned char *addr)
580{
581	return __dev_mc_del(dev, addr, true);
582}
583EXPORT_SYMBOL(dev_mc_del_global);
584
585/**
586 *	dev_mc_sync - Synchronize device's unicast list to another device
587 *	@to: destination device
588 *	@from: source device
589 *
590 *	Add newly added addresses to the destination device and release
591 *	addresses that have no users left. The source device must be
592 *	locked by netif_tx_lock_bh.
593 *
594 *	This function is intended to be called from the dev->set_multicast_list
595 *	or dev->set_rx_mode function of layered software devices.
596 */
597int dev_mc_sync(struct net_device *to, struct net_device *from)
598{
599	int err = 0;
600
601	if (to->addr_len != from->addr_len)
602		return -EINVAL;
603
604	netif_addr_lock_bh(to);
605	err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
606	if (!err)
607		__dev_set_rx_mode(to);
608	netif_addr_unlock_bh(to);
609	return err;
610}
611EXPORT_SYMBOL(dev_mc_sync);
612
613/**
614 *	dev_mc_unsync - Remove synchronized addresses from the destination device
615 *	@to: destination device
616 *	@from: source device
617 *
618 *	Remove all addresses that were added to the destination device by
619 *	dev_mc_sync(). This function is intended to be called from the
620 *	dev->stop function of layered software devices.
621 */
622void dev_mc_unsync(struct net_device *to, struct net_device *from)
623{
624	if (to->addr_len != from->addr_len)
625		return;
626
627	netif_addr_lock_bh(from);
628	netif_addr_lock(to);
629	__hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
630	__dev_set_rx_mode(to);
631	netif_addr_unlock(to);
632	netif_addr_unlock_bh(from);
633}
634EXPORT_SYMBOL(dev_mc_unsync);
635
636/**
637 *	dev_mc_flush - Flush multicast addresses
638 *	@dev: device
639 *
640 *	Flush multicast addresses.
641 */
642void dev_mc_flush(struct net_device *dev)
643{
644	netif_addr_lock_bh(dev);
645	__hw_addr_flush(&dev->mc);
646	netif_addr_unlock_bh(dev);
647}
648EXPORT_SYMBOL(dev_mc_flush);
649
650/**
651 *	dev_mc_flush - Init multicast address list
652 *	@dev: device
653 *
654 *	Init multicast address list.
655 */
656void dev_mc_init(struct net_device *dev)
657{
658	__hw_addr_init(&dev->mc);
659}
660EXPORT_SYMBOL(dev_mc_init);
661
662#ifdef CONFIG_PROC_FS
663#include <linux/seq_file.h>
664
665static int dev_mc_seq_show(struct seq_file *seq, void *v)
666{
667	struct netdev_hw_addr *ha;
668	struct net_device *dev = v;
669
670	if (v == SEQ_START_TOKEN)
671		return 0;
672
673	netif_addr_lock_bh(dev);
674	netdev_for_each_mc_addr(ha, dev) {
675		int i;
676
677		seq_printf(seq, "%-4d %-15s %-5d %-5d ", dev->ifindex,
678			   dev->name, ha->refcount, ha->global_use);
679
680		for (i = 0; i < dev->addr_len; i++)
681			seq_printf(seq, "%02x", ha->addr[i]);
682
683		seq_putc(seq, '\n');
684	}
685	netif_addr_unlock_bh(dev);
686	return 0;
687}
688
689static const struct seq_operations dev_mc_seq_ops = {
690	.start = dev_seq_start,
691	.next  = dev_seq_next,
692	.stop  = dev_seq_stop,
693	.show  = dev_mc_seq_show,
694};
695
696static int dev_mc_seq_open(struct inode *inode, struct file *file)
697{
698	return seq_open_net(inode, file, &dev_mc_seq_ops,
699			    sizeof(struct seq_net_private));
700}
701
702static const struct file_operations dev_mc_seq_fops = {
703	.owner	 = THIS_MODULE,
704	.open    = dev_mc_seq_open,
705	.read    = seq_read,
706	.llseek  = seq_lseek,
707	.release = seq_release_net,
708};
709
710#endif
711
712static int __net_init dev_mc_net_init(struct net *net)
713{
714	if (!proc_net_fops_create(net, "dev_mcast", 0, &dev_mc_seq_fops))
715		return -ENOMEM;
716	return 0;
717}
718
719static void __net_exit dev_mc_net_exit(struct net *net)
720{
721	proc_net_remove(net, "dev_mcast");
722}
723
724static struct pernet_operations __net_initdata dev_mc_net_ops = {
725	.init = dev_mc_net_init,
726	.exit = dev_mc_net_exit,
727};
728
729void __init dev_mcast_init(void)
730{
731	register_pernet_subsys(&dev_mc_net_ops);
732}
733