xref: /openbmc/linux/net/ipv4/igmp.c (revision 7f6964c5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Linux NET3:	Internet Group Management Protocol  [IGMP]
4  *
5  *	This code implements the IGMP protocol as defined in RFC1112. There has
6  *	been a further revision of this protocol since which is now supported.
7  *
8  *	If you have trouble with this module be careful what gcc you have used,
9  *	the older version didn't come out right using gcc 2.5.8, the newer one
10  *	seems to fall out with gcc 2.6.2.
11  *
12  *	Authors:
13  *		Alan Cox <alan@lxorguk.ukuu.org.uk>
14  *
15  *	Fixes:
16  *
17  *		Alan Cox	:	Added lots of __inline__ to optimise
18  *					the memory usage of all the tiny little
19  *					functions.
20  *		Alan Cox	:	Dumped the header building experiment.
21  *		Alan Cox	:	Minor tweaks ready for multicast routing
22  *					and extended IGMP protocol.
23  *		Alan Cox	:	Removed a load of inline directives. Gcc 2.5.8
24  *					writes utterly bogus code otherwise (sigh)
25  *					fixed IGMP loopback to behave in the manner
26  *					desired by mrouted, fixed the fact it has been
27  *					broken since 1.3.6 and cleaned up a few minor
28  *					points.
29  *
30  *		Chih-Jen Chang	:	Tried to revise IGMP to Version 2
31  *		Tsu-Sheng Tsao		E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
32  *					The enhancements are mainly based on Steve Deering's
33  * 					ipmulti-3.5 source code.
34  *		Chih-Jen Chang	:	Added the igmp_get_mrouter_info and
35  *		Tsu-Sheng Tsao		igmp_set_mrouter_info to keep track of
36  *					the mrouted version on that device.
37  *		Chih-Jen Chang	:	Added the max_resp_time parameter to
38  *		Tsu-Sheng Tsao		igmp_heard_query(). Using this parameter
39  *					to identify the multicast router version
40  *					and do what the IGMP version 2 specified.
41  *		Chih-Jen Chang	:	Added a timer to revert to IGMP V2 router
42  *		Tsu-Sheng Tsao		if the specified time expired.
43  *		Alan Cox	:	Stop IGMP from 0.0.0.0 being accepted.
44  *		Alan Cox	:	Use GFP_ATOMIC in the right places.
45  *		Christian Daudt :	igmp timer wasn't set for local group
46  *					memberships but was being deleted,
47  *					which caused a "del_timer() called
48  *					from %p with timer not initialized\n"
49  *					message (960131).
50  *		Christian Daudt :	removed del_timer from
51  *					igmp_timer_expire function (960205).
52  *             Christian Daudt :       igmp_heard_report now only calls
53  *                                     igmp_timer_expire if tm->running is
54  *                                     true (960216).
55  *		Malcolm Beattie :	ttl comparison wrong in igmp_rcv made
56  *					igmp_heard_query never trigger. Expiry
57  *					miscalculation fixed in igmp_heard_query
58  *					and random() made to return unsigned to
59  *					prevent negative expiry times.
60  *		Alexey Kuznetsov:	Wrong group leaving behaviour, backport
61  *					fix from pending 2.1.x patches.
62  *		Alan Cox:		Forget to enable FDDI support earlier.
63  *		Alexey Kuznetsov:	Fixed leaving groups on device down.
64  *		Alexey Kuznetsov:	Accordance to igmp-v2-06 draft.
65  *		David L Stevens:	IGMPv3 support, with help from
66  *					Vinay Kulkarni
67  */
68 
69 #include <linux/module.h>
70 #include <linux/slab.h>
71 #include <linux/uaccess.h>
72 #include <linux/types.h>
73 #include <linux/kernel.h>
74 #include <linux/jiffies.h>
75 #include <linux/string.h>
76 #include <linux/socket.h>
77 #include <linux/sockios.h>
78 #include <linux/in.h>
79 #include <linux/inet.h>
80 #include <linux/netdevice.h>
81 #include <linux/skbuff.h>
82 #include <linux/inetdevice.h>
83 #include <linux/igmp.h>
84 #include <linux/if_arp.h>
85 #include <linux/rtnetlink.h>
86 #include <linux/times.h>
87 #include <linux/pkt_sched.h>
88 #include <linux/byteorder/generic.h>
89 
90 #include <net/net_namespace.h>
91 #include <net/arp.h>
92 #include <net/ip.h>
93 #include <net/protocol.h>
94 #include <net/route.h>
95 #include <net/sock.h>
96 #include <net/checksum.h>
97 #include <net/inet_common.h>
98 #include <linux/netfilter_ipv4.h>
99 #ifdef CONFIG_IP_MROUTE
100 #include <linux/mroute.h>
101 #endif
102 #ifdef CONFIG_PROC_FS
103 #include <linux/proc_fs.h>
104 #include <linux/seq_file.h>
105 #endif
106 
107 #ifdef CONFIG_IP_MULTICAST
108 /* Parameter names and values are taken from igmp-v2-06 draft */
109 
110 #define IGMP_V2_UNSOLICITED_REPORT_INTERVAL	(10*HZ)
111 #define IGMP_V3_UNSOLICITED_REPORT_INTERVAL	(1*HZ)
112 #define IGMP_QUERY_INTERVAL			(125*HZ)
113 #define IGMP_QUERY_RESPONSE_INTERVAL		(10*HZ)
114 
115 #define IGMP_INITIAL_REPORT_DELAY		(1)
116 
117 /* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
118  * IGMP specs require to report membership immediately after
119  * joining a group, but we delay the first report by a
120  * small interval. It seems more natural and still does not
121  * contradict to specs provided this delay is small enough.
122  */
123 
124 #define IGMP_V1_SEEN(in_dev) \
125 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
126 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
127 	 ((in_dev)->mr_v1_seen && \
128 	  time_before(jiffies, (in_dev)->mr_v1_seen)))
129 #define IGMP_V2_SEEN(in_dev) \
130 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
131 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
132 	 ((in_dev)->mr_v2_seen && \
133 	  time_before(jiffies, (in_dev)->mr_v2_seen)))
134 
135 static int unsolicited_report_interval(struct in_device *in_dev)
136 {
137 	int interval_ms, interval_jiffies;
138 
139 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
140 		interval_ms = IN_DEV_CONF_GET(
141 			in_dev,
142 			IGMPV2_UNSOLICITED_REPORT_INTERVAL);
143 	else /* v3 */
144 		interval_ms = IN_DEV_CONF_GET(
145 			in_dev,
146 			IGMPV3_UNSOLICITED_REPORT_INTERVAL);
147 
148 	interval_jiffies = msecs_to_jiffies(interval_ms);
149 
150 	/* _timer functions can't handle a delay of 0 jiffies so ensure
151 	 *  we always return a positive value.
152 	 */
153 	if (interval_jiffies <= 0)
154 		interval_jiffies = 1;
155 	return interval_jiffies;
156 }
157 
158 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
159 			      gfp_t gfp);
160 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im);
161 static void igmpv3_clear_delrec(struct in_device *in_dev);
162 static int sf_setstate(struct ip_mc_list *pmc);
163 static void sf_markstate(struct ip_mc_list *pmc);
164 #endif
165 static void ip_mc_clear_src(struct ip_mc_list *pmc);
166 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
167 			 int sfcount, __be32 *psfsrc, int delta);
168 
169 static void ip_ma_put(struct ip_mc_list *im)
170 {
171 	if (refcount_dec_and_test(&im->refcnt)) {
172 		in_dev_put(im->interface);
173 		kfree_rcu(im, rcu);
174 	}
175 }
176 
177 #define for_each_pmc_rcu(in_dev, pmc)				\
178 	for (pmc = rcu_dereference(in_dev->mc_list);		\
179 	     pmc != NULL;					\
180 	     pmc = rcu_dereference(pmc->next_rcu))
181 
182 #define for_each_pmc_rtnl(in_dev, pmc)				\
183 	for (pmc = rtnl_dereference(in_dev->mc_list);		\
184 	     pmc != NULL;					\
185 	     pmc = rtnl_dereference(pmc->next_rcu))
186 
187 static void ip_sf_list_clear_all(struct ip_sf_list *psf)
188 {
189 	struct ip_sf_list *next;
190 
191 	while (psf) {
192 		next = psf->sf_next;
193 		kfree(psf);
194 		psf = next;
195 	}
196 }
197 
198 #ifdef CONFIG_IP_MULTICAST
199 
200 /*
201  *	Timer management
202  */
203 
204 static void igmp_stop_timer(struct ip_mc_list *im)
205 {
206 	spin_lock_bh(&im->lock);
207 	if (del_timer(&im->timer))
208 		refcount_dec(&im->refcnt);
209 	im->tm_running = 0;
210 	im->reporter = 0;
211 	im->unsolicit_count = 0;
212 	spin_unlock_bh(&im->lock);
213 }
214 
215 /* It must be called with locked im->lock */
216 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
217 {
218 	int tv = prandom_u32() % max_delay;
219 
220 	im->tm_running = 1;
221 	if (!mod_timer(&im->timer, jiffies+tv+2))
222 		refcount_inc(&im->refcnt);
223 }
224 
225 static void igmp_gq_start_timer(struct in_device *in_dev)
226 {
227 	int tv = prandom_u32() % in_dev->mr_maxdelay;
228 	unsigned long exp = jiffies + tv + 2;
229 
230 	if (in_dev->mr_gq_running &&
231 	    time_after_eq(exp, (in_dev->mr_gq_timer).expires))
232 		return;
233 
234 	in_dev->mr_gq_running = 1;
235 	if (!mod_timer(&in_dev->mr_gq_timer, exp))
236 		in_dev_hold(in_dev);
237 }
238 
239 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
240 {
241 	int tv = prandom_u32() % delay;
242 
243 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
244 		in_dev_hold(in_dev);
245 }
246 
247 static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
248 {
249 	spin_lock_bh(&im->lock);
250 	im->unsolicit_count = 0;
251 	if (del_timer(&im->timer)) {
252 		if ((long)(im->timer.expires-jiffies) < max_delay) {
253 			add_timer(&im->timer);
254 			im->tm_running = 1;
255 			spin_unlock_bh(&im->lock);
256 			return;
257 		}
258 		refcount_dec(&im->refcnt);
259 	}
260 	igmp_start_timer(im, max_delay);
261 	spin_unlock_bh(&im->lock);
262 }
263 
264 
265 /*
266  *	Send an IGMP report.
267  */
268 
269 #define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
270 
271 
272 static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
273 	int gdeleted, int sdeleted)
274 {
275 	switch (type) {
276 	case IGMPV3_MODE_IS_INCLUDE:
277 	case IGMPV3_MODE_IS_EXCLUDE:
278 		if (gdeleted || sdeleted)
279 			return 0;
280 		if (!(pmc->gsquery && !psf->sf_gsresp)) {
281 			if (pmc->sfmode == MCAST_INCLUDE)
282 				return 1;
283 			/* don't include if this source is excluded
284 			 * in all filters
285 			 */
286 			if (psf->sf_count[MCAST_INCLUDE])
287 				return type == IGMPV3_MODE_IS_INCLUDE;
288 			return pmc->sfcount[MCAST_EXCLUDE] ==
289 				psf->sf_count[MCAST_EXCLUDE];
290 		}
291 		return 0;
292 	case IGMPV3_CHANGE_TO_INCLUDE:
293 		if (gdeleted || sdeleted)
294 			return 0;
295 		return psf->sf_count[MCAST_INCLUDE] != 0;
296 	case IGMPV3_CHANGE_TO_EXCLUDE:
297 		if (gdeleted || sdeleted)
298 			return 0;
299 		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
300 		    psf->sf_count[MCAST_INCLUDE])
301 			return 0;
302 		return pmc->sfcount[MCAST_EXCLUDE] ==
303 			psf->sf_count[MCAST_EXCLUDE];
304 	case IGMPV3_ALLOW_NEW_SOURCES:
305 		if (gdeleted || !psf->sf_crcount)
306 			return 0;
307 		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
308 	case IGMPV3_BLOCK_OLD_SOURCES:
309 		if (pmc->sfmode == MCAST_INCLUDE)
310 			return gdeleted || (psf->sf_crcount && sdeleted);
311 		return psf->sf_crcount && !gdeleted && !sdeleted;
312 	}
313 	return 0;
314 }
315 
316 static int
317 igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
318 {
319 	struct ip_sf_list *psf;
320 	int scount = 0;
321 
322 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
323 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
324 			continue;
325 		scount++;
326 	}
327 	return scount;
328 }
329 
330 /* source address selection per RFC 3376 section 4.2.13 */
331 static __be32 igmpv3_get_srcaddr(struct net_device *dev,
332 				 const struct flowi4 *fl4)
333 {
334 	struct in_device *in_dev = __in_dev_get_rcu(dev);
335 
336 	if (!in_dev)
337 		return htonl(INADDR_ANY);
338 
339 	for_ifa(in_dev) {
340 		if (fl4->saddr == ifa->ifa_local)
341 			return fl4->saddr;
342 	} endfor_ifa(in_dev);
343 
344 	return htonl(INADDR_ANY);
345 }
346 
347 static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
348 {
349 	struct sk_buff *skb;
350 	struct rtable *rt;
351 	struct iphdr *pip;
352 	struct igmpv3_report *pig;
353 	struct net *net = dev_net(dev);
354 	struct flowi4 fl4;
355 	int hlen = LL_RESERVED_SPACE(dev);
356 	int tlen = dev->needed_tailroom;
357 	unsigned int size = mtu;
358 
359 	while (1) {
360 		skb = alloc_skb(size + hlen + tlen,
361 				GFP_ATOMIC | __GFP_NOWARN);
362 		if (skb)
363 			break;
364 		size >>= 1;
365 		if (size < 256)
366 			return NULL;
367 	}
368 	skb->priority = TC_PRIO_CONTROL;
369 
370 	rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
371 				   0, 0,
372 				   IPPROTO_IGMP, 0, dev->ifindex);
373 	if (IS_ERR(rt)) {
374 		kfree_skb(skb);
375 		return NULL;
376 	}
377 
378 	skb_dst_set(skb, &rt->dst);
379 	skb->dev = dev;
380 
381 	skb_reserve(skb, hlen);
382 	skb_tailroom_reserve(skb, mtu, tlen);
383 
384 	skb_reset_network_header(skb);
385 	pip = ip_hdr(skb);
386 	skb_put(skb, sizeof(struct iphdr) + 4);
387 
388 	pip->version  = 4;
389 	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
390 	pip->tos      = 0xc0;
391 	pip->frag_off = htons(IP_DF);
392 	pip->ttl      = 1;
393 	pip->daddr    = fl4.daddr;
394 
395 	rcu_read_lock();
396 	pip->saddr    = igmpv3_get_srcaddr(dev, &fl4);
397 	rcu_read_unlock();
398 
399 	pip->protocol = IPPROTO_IGMP;
400 	pip->tot_len  = 0;	/* filled in later */
401 	ip_select_ident(net, skb, NULL);
402 	((u8 *)&pip[1])[0] = IPOPT_RA;
403 	((u8 *)&pip[1])[1] = 4;
404 	((u8 *)&pip[1])[2] = 0;
405 	((u8 *)&pip[1])[3] = 0;
406 
407 	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
408 	skb_put(skb, sizeof(*pig));
409 	pig = igmpv3_report_hdr(skb);
410 	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
411 	pig->resv1 = 0;
412 	pig->csum = 0;
413 	pig->resv2 = 0;
414 	pig->ngrec = 0;
415 	return skb;
416 }
417 
418 static int igmpv3_sendpack(struct sk_buff *skb)
419 {
420 	struct igmphdr *pig = igmp_hdr(skb);
421 	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
422 
423 	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
424 
425 	return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
426 }
427 
428 static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
429 {
430 	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
431 }
432 
433 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
434 	int type, struct igmpv3_grec **ppgr, unsigned int mtu)
435 {
436 	struct net_device *dev = pmc->interface->dev;
437 	struct igmpv3_report *pih;
438 	struct igmpv3_grec *pgr;
439 
440 	if (!skb) {
441 		skb = igmpv3_newpack(dev, mtu);
442 		if (!skb)
443 			return NULL;
444 	}
445 	pgr = skb_put(skb, sizeof(struct igmpv3_grec));
446 	pgr->grec_type = type;
447 	pgr->grec_auxwords = 0;
448 	pgr->grec_nsrcs = 0;
449 	pgr->grec_mca = pmc->multiaddr;
450 	pih = igmpv3_report_hdr(skb);
451 	pih->ngrec = htons(ntohs(pih->ngrec)+1);
452 	*ppgr = pgr;
453 	return skb;
454 }
455 
456 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
457 
458 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
459 	int type, int gdeleted, int sdeleted)
460 {
461 	struct net_device *dev = pmc->interface->dev;
462 	struct net *net = dev_net(dev);
463 	struct igmpv3_report *pih;
464 	struct igmpv3_grec *pgr = NULL;
465 	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
466 	int scount, stotal, first, isquery, truncate;
467 	unsigned int mtu;
468 
469 	if (pmc->multiaddr == IGMP_ALL_HOSTS)
470 		return skb;
471 	if (ipv4_is_local_multicast(pmc->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
472 		return skb;
473 
474 	mtu = READ_ONCE(dev->mtu);
475 	if (mtu < IPV4_MIN_MTU)
476 		return skb;
477 
478 	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
479 		  type == IGMPV3_MODE_IS_EXCLUDE;
480 	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
481 		    type == IGMPV3_CHANGE_TO_EXCLUDE;
482 
483 	stotal = scount = 0;
484 
485 	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
486 
487 	if (!*psf_list)
488 		goto empty_source;
489 
490 	pih = skb ? igmpv3_report_hdr(skb) : NULL;
491 
492 	/* EX and TO_EX get a fresh packet, if needed */
493 	if (truncate) {
494 		if (pih && pih->ngrec &&
495 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
496 			if (skb)
497 				igmpv3_sendpack(skb);
498 			skb = igmpv3_newpack(dev, mtu);
499 		}
500 	}
501 	first = 1;
502 	psf_prev = NULL;
503 	for (psf = *psf_list; psf; psf = psf_next) {
504 		__be32 *psrc;
505 
506 		psf_next = psf->sf_next;
507 
508 		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
509 			psf_prev = psf;
510 			continue;
511 		}
512 
513 		/* Based on RFC3376 5.1. Should not send source-list change
514 		 * records when there is a filter mode change.
515 		 */
516 		if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) ||
517 		     (!gdeleted && pmc->crcount)) &&
518 		    (type == IGMPV3_ALLOW_NEW_SOURCES ||
519 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount)
520 			goto decrease_sf_crcount;
521 
522 		/* clear marks on query responses */
523 		if (isquery)
524 			psf->sf_gsresp = 0;
525 
526 		if (AVAILABLE(skb) < sizeof(__be32) +
527 		    first*sizeof(struct igmpv3_grec)) {
528 			if (truncate && !first)
529 				break;	 /* truncate these */
530 			if (pgr)
531 				pgr->grec_nsrcs = htons(scount);
532 			if (skb)
533 				igmpv3_sendpack(skb);
534 			skb = igmpv3_newpack(dev, mtu);
535 			first = 1;
536 			scount = 0;
537 		}
538 		if (first) {
539 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
540 			first = 0;
541 		}
542 		if (!skb)
543 			return NULL;
544 		psrc = skb_put(skb, sizeof(__be32));
545 		*psrc = psf->sf_inaddr;
546 		scount++; stotal++;
547 		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
548 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
549 decrease_sf_crcount:
550 			psf->sf_crcount--;
551 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
552 				if (psf_prev)
553 					psf_prev->sf_next = psf->sf_next;
554 				else
555 					*psf_list = psf->sf_next;
556 				kfree(psf);
557 				continue;
558 			}
559 		}
560 		psf_prev = psf;
561 	}
562 
563 empty_source:
564 	if (!stotal) {
565 		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
566 		    type == IGMPV3_BLOCK_OLD_SOURCES)
567 			return skb;
568 		if (pmc->crcount || isquery) {
569 			/* make sure we have room for group header */
570 			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
571 				igmpv3_sendpack(skb);
572 				skb = NULL; /* add_grhead will get a new one */
573 			}
574 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
575 		}
576 	}
577 	if (pgr)
578 		pgr->grec_nsrcs = htons(scount);
579 
580 	if (isquery)
581 		pmc->gsquery = 0;	/* clear query state on report */
582 	return skb;
583 }
584 
585 static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
586 {
587 	struct sk_buff *skb = NULL;
588 	struct net *net = dev_net(in_dev->dev);
589 	int type;
590 
591 	if (!pmc) {
592 		rcu_read_lock();
593 		for_each_pmc_rcu(in_dev, pmc) {
594 			if (pmc->multiaddr == IGMP_ALL_HOSTS)
595 				continue;
596 			if (ipv4_is_local_multicast(pmc->multiaddr) &&
597 			     !net->ipv4.sysctl_igmp_llm_reports)
598 				continue;
599 			spin_lock_bh(&pmc->lock);
600 			if (pmc->sfcount[MCAST_EXCLUDE])
601 				type = IGMPV3_MODE_IS_EXCLUDE;
602 			else
603 				type = IGMPV3_MODE_IS_INCLUDE;
604 			skb = add_grec(skb, pmc, type, 0, 0);
605 			spin_unlock_bh(&pmc->lock);
606 		}
607 		rcu_read_unlock();
608 	} else {
609 		spin_lock_bh(&pmc->lock);
610 		if (pmc->sfcount[MCAST_EXCLUDE])
611 			type = IGMPV3_MODE_IS_EXCLUDE;
612 		else
613 			type = IGMPV3_MODE_IS_INCLUDE;
614 		skb = add_grec(skb, pmc, type, 0, 0);
615 		spin_unlock_bh(&pmc->lock);
616 	}
617 	if (!skb)
618 		return 0;
619 	return igmpv3_sendpack(skb);
620 }
621 
622 /*
623  * remove zero-count source records from a source filter list
624  */
625 static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
626 {
627 	struct ip_sf_list *psf_prev, *psf_next, *psf;
628 
629 	psf_prev = NULL;
630 	for (psf = *ppsf; psf; psf = psf_next) {
631 		psf_next = psf->sf_next;
632 		if (psf->sf_crcount == 0) {
633 			if (psf_prev)
634 				psf_prev->sf_next = psf->sf_next;
635 			else
636 				*ppsf = psf->sf_next;
637 			kfree(psf);
638 		} else
639 			psf_prev = psf;
640 	}
641 }
642 
643 static void kfree_pmc(struct ip_mc_list *pmc)
644 {
645 	ip_sf_list_clear_all(pmc->sources);
646 	ip_sf_list_clear_all(pmc->tomb);
647 	kfree(pmc);
648 }
649 
650 static void igmpv3_send_cr(struct in_device *in_dev)
651 {
652 	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
653 	struct sk_buff *skb = NULL;
654 	int type, dtype;
655 
656 	rcu_read_lock();
657 	spin_lock_bh(&in_dev->mc_tomb_lock);
658 
659 	/* deleted MCA's */
660 	pmc_prev = NULL;
661 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
662 		pmc_next = pmc->next;
663 		if (pmc->sfmode == MCAST_INCLUDE) {
664 			type = IGMPV3_BLOCK_OLD_SOURCES;
665 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
666 			skb = add_grec(skb, pmc, type, 1, 0);
667 			skb = add_grec(skb, pmc, dtype, 1, 1);
668 		}
669 		if (pmc->crcount) {
670 			if (pmc->sfmode == MCAST_EXCLUDE) {
671 				type = IGMPV3_CHANGE_TO_INCLUDE;
672 				skb = add_grec(skb, pmc, type, 1, 0);
673 			}
674 			pmc->crcount--;
675 			if (pmc->crcount == 0) {
676 				igmpv3_clear_zeros(&pmc->tomb);
677 				igmpv3_clear_zeros(&pmc->sources);
678 			}
679 		}
680 		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
681 			if (pmc_prev)
682 				pmc_prev->next = pmc_next;
683 			else
684 				in_dev->mc_tomb = pmc_next;
685 			in_dev_put(pmc->interface);
686 			kfree_pmc(pmc);
687 		} else
688 			pmc_prev = pmc;
689 	}
690 	spin_unlock_bh(&in_dev->mc_tomb_lock);
691 
692 	/* change recs */
693 	for_each_pmc_rcu(in_dev, pmc) {
694 		spin_lock_bh(&pmc->lock);
695 		if (pmc->sfcount[MCAST_EXCLUDE]) {
696 			type = IGMPV3_BLOCK_OLD_SOURCES;
697 			dtype = IGMPV3_ALLOW_NEW_SOURCES;
698 		} else {
699 			type = IGMPV3_ALLOW_NEW_SOURCES;
700 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
701 		}
702 		skb = add_grec(skb, pmc, type, 0, 0);
703 		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
704 
705 		/* filter mode changes */
706 		if (pmc->crcount) {
707 			if (pmc->sfmode == MCAST_EXCLUDE)
708 				type = IGMPV3_CHANGE_TO_EXCLUDE;
709 			else
710 				type = IGMPV3_CHANGE_TO_INCLUDE;
711 			skb = add_grec(skb, pmc, type, 0, 0);
712 			pmc->crcount--;
713 		}
714 		spin_unlock_bh(&pmc->lock);
715 	}
716 	rcu_read_unlock();
717 
718 	if (!skb)
719 		return;
720 	(void) igmpv3_sendpack(skb);
721 }
722 
723 static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
724 	int type)
725 {
726 	struct sk_buff *skb;
727 	struct iphdr *iph;
728 	struct igmphdr *ih;
729 	struct rtable *rt;
730 	struct net_device *dev = in_dev->dev;
731 	struct net *net = dev_net(dev);
732 	__be32	group = pmc ? pmc->multiaddr : 0;
733 	struct flowi4 fl4;
734 	__be32	dst;
735 	int hlen, tlen;
736 
737 	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
738 		return igmpv3_send_report(in_dev, pmc);
739 
740 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
741 		return 0;
742 
743 	if (type == IGMP_HOST_LEAVE_MESSAGE)
744 		dst = IGMP_ALL_ROUTER;
745 	else
746 		dst = group;
747 
748 	rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
749 				   0, 0,
750 				   IPPROTO_IGMP, 0, dev->ifindex);
751 	if (IS_ERR(rt))
752 		return -1;
753 
754 	hlen = LL_RESERVED_SPACE(dev);
755 	tlen = dev->needed_tailroom;
756 	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
757 	if (!skb) {
758 		ip_rt_put(rt);
759 		return -1;
760 	}
761 	skb->priority = TC_PRIO_CONTROL;
762 
763 	skb_dst_set(skb, &rt->dst);
764 
765 	skb_reserve(skb, hlen);
766 
767 	skb_reset_network_header(skb);
768 	iph = ip_hdr(skb);
769 	skb_put(skb, sizeof(struct iphdr) + 4);
770 
771 	iph->version  = 4;
772 	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
773 	iph->tos      = 0xc0;
774 	iph->frag_off = htons(IP_DF);
775 	iph->ttl      = 1;
776 	iph->daddr    = dst;
777 	iph->saddr    = fl4.saddr;
778 	iph->protocol = IPPROTO_IGMP;
779 	ip_select_ident(net, skb, NULL);
780 	((u8 *)&iph[1])[0] = IPOPT_RA;
781 	((u8 *)&iph[1])[1] = 4;
782 	((u8 *)&iph[1])[2] = 0;
783 	((u8 *)&iph[1])[3] = 0;
784 
785 	ih = skb_put(skb, sizeof(struct igmphdr));
786 	ih->type = type;
787 	ih->code = 0;
788 	ih->csum = 0;
789 	ih->group = group;
790 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
791 
792 	return ip_local_out(net, skb->sk, skb);
793 }
794 
795 static void igmp_gq_timer_expire(struct timer_list *t)
796 {
797 	struct in_device *in_dev = from_timer(in_dev, t, mr_gq_timer);
798 
799 	in_dev->mr_gq_running = 0;
800 	igmpv3_send_report(in_dev, NULL);
801 	in_dev_put(in_dev);
802 }
803 
804 static void igmp_ifc_timer_expire(struct timer_list *t)
805 {
806 	struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer);
807 
808 	igmpv3_send_cr(in_dev);
809 	if (in_dev->mr_ifc_count) {
810 		in_dev->mr_ifc_count--;
811 		igmp_ifc_start_timer(in_dev,
812 				     unsolicited_report_interval(in_dev));
813 	}
814 	in_dev_put(in_dev);
815 }
816 
817 static void igmp_ifc_event(struct in_device *in_dev)
818 {
819 	struct net *net = dev_net(in_dev->dev);
820 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
821 		return;
822 	in_dev->mr_ifc_count = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
823 	igmp_ifc_start_timer(in_dev, 1);
824 }
825 
826 
827 static void igmp_timer_expire(struct timer_list *t)
828 {
829 	struct ip_mc_list *im = from_timer(im, t, timer);
830 	struct in_device *in_dev = im->interface;
831 
832 	spin_lock(&im->lock);
833 	im->tm_running = 0;
834 
835 	if (im->unsolicit_count && --im->unsolicit_count)
836 		igmp_start_timer(im, unsolicited_report_interval(in_dev));
837 
838 	im->reporter = 1;
839 	spin_unlock(&im->lock);
840 
841 	if (IGMP_V1_SEEN(in_dev))
842 		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
843 	else if (IGMP_V2_SEEN(in_dev))
844 		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
845 	else
846 		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
847 
848 	ip_ma_put(im);
849 }
850 
851 /* mark EXCLUDE-mode sources */
852 static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
853 {
854 	struct ip_sf_list *psf;
855 	int i, scount;
856 
857 	scount = 0;
858 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
859 		if (scount == nsrcs)
860 			break;
861 		for (i = 0; i < nsrcs; i++) {
862 			/* skip inactive filters */
863 			if (psf->sf_count[MCAST_INCLUDE] ||
864 			    pmc->sfcount[MCAST_EXCLUDE] !=
865 			    psf->sf_count[MCAST_EXCLUDE])
866 				break;
867 			if (srcs[i] == psf->sf_inaddr) {
868 				scount++;
869 				break;
870 			}
871 		}
872 	}
873 	pmc->gsquery = 0;
874 	if (scount == nsrcs)	/* all sources excluded */
875 		return 0;
876 	return 1;
877 }
878 
879 static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
880 {
881 	struct ip_sf_list *psf;
882 	int i, scount;
883 
884 	if (pmc->sfmode == MCAST_EXCLUDE)
885 		return igmp_xmarksources(pmc, nsrcs, srcs);
886 
887 	/* mark INCLUDE-mode sources */
888 	scount = 0;
889 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
890 		if (scount == nsrcs)
891 			break;
892 		for (i = 0; i < nsrcs; i++)
893 			if (srcs[i] == psf->sf_inaddr) {
894 				psf->sf_gsresp = 1;
895 				scount++;
896 				break;
897 			}
898 	}
899 	if (!scount) {
900 		pmc->gsquery = 0;
901 		return 0;
902 	}
903 	pmc->gsquery = 1;
904 	return 1;
905 }
906 
907 /* return true if packet was dropped */
908 static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
909 {
910 	struct ip_mc_list *im;
911 	struct net *net = dev_net(in_dev->dev);
912 
913 	/* Timers are only set for non-local groups */
914 
915 	if (group == IGMP_ALL_HOSTS)
916 		return false;
917 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
918 		return false;
919 
920 	rcu_read_lock();
921 	for_each_pmc_rcu(in_dev, im) {
922 		if (im->multiaddr == group) {
923 			igmp_stop_timer(im);
924 			break;
925 		}
926 	}
927 	rcu_read_unlock();
928 	return false;
929 }
930 
931 /* return true if packet was dropped */
932 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
933 	int len)
934 {
935 	struct igmphdr 		*ih = igmp_hdr(skb);
936 	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
937 	struct ip_mc_list	*im;
938 	__be32			group = ih->group;
939 	int			max_delay;
940 	int			mark = 0;
941 	struct net		*net = dev_net(in_dev->dev);
942 
943 
944 	if (len == 8) {
945 		if (ih->code == 0) {
946 			/* Alas, old v1 router presents here. */
947 
948 			max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
949 			in_dev->mr_v1_seen = jiffies +
950 				(in_dev->mr_qrv * in_dev->mr_qi) +
951 				in_dev->mr_qri;
952 			group = 0;
953 		} else {
954 			/* v2 router present */
955 			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
956 			in_dev->mr_v2_seen = jiffies +
957 				(in_dev->mr_qrv * in_dev->mr_qi) +
958 				in_dev->mr_qri;
959 		}
960 		/* cancel the interface change timer */
961 		in_dev->mr_ifc_count = 0;
962 		if (del_timer(&in_dev->mr_ifc_timer))
963 			__in_dev_put(in_dev);
964 		/* clear deleted report items */
965 		igmpv3_clear_delrec(in_dev);
966 	} else if (len < 12) {
967 		return true;	/* ignore bogus packet; freed by caller */
968 	} else if (IGMP_V1_SEEN(in_dev)) {
969 		/* This is a v3 query with v1 queriers present */
970 		max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
971 		group = 0;
972 	} else if (IGMP_V2_SEEN(in_dev)) {
973 		/* this is a v3 query with v2 queriers present;
974 		 * Interpretation of the max_delay code is problematic here.
975 		 * A real v2 host would use ih_code directly, while v3 has a
976 		 * different encoding. We use the v3 encoding as more likely
977 		 * to be intended in a v3 query.
978 		 */
979 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
980 		if (!max_delay)
981 			max_delay = 1;	/* can't mod w/ 0 */
982 	} else { /* v3 */
983 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
984 			return true;
985 
986 		ih3 = igmpv3_query_hdr(skb);
987 		if (ih3->nsrcs) {
988 			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
989 					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
990 				return true;
991 			ih3 = igmpv3_query_hdr(skb);
992 		}
993 
994 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
995 		if (!max_delay)
996 			max_delay = 1;	/* can't mod w/ 0 */
997 		in_dev->mr_maxdelay = max_delay;
998 
999 		/* RFC3376, 4.1.6. QRV and 4.1.7. QQIC, when the most recently
1000 		 * received value was zero, use the default or statically
1001 		 * configured value.
1002 		 */
1003 		in_dev->mr_qrv = ih3->qrv ?: net->ipv4.sysctl_igmp_qrv;
1004 		in_dev->mr_qi = IGMPV3_QQIC(ih3->qqic)*HZ ?: IGMP_QUERY_INTERVAL;
1005 
1006 		/* RFC3376, 8.3. Query Response Interval:
1007 		 * The number of seconds represented by the [Query Response
1008 		 * Interval] must be less than the [Query Interval].
1009 		 */
1010 		if (in_dev->mr_qri >= in_dev->mr_qi)
1011 			in_dev->mr_qri = (in_dev->mr_qi/HZ - 1)*HZ;
1012 
1013 		if (!group) { /* general query */
1014 			if (ih3->nsrcs)
1015 				return true;	/* no sources allowed */
1016 			igmp_gq_start_timer(in_dev);
1017 			return false;
1018 		}
1019 		/* mark sources to include, if group & source-specific */
1020 		mark = ih3->nsrcs != 0;
1021 	}
1022 
1023 	/*
1024 	 * - Start the timers in all of our membership records
1025 	 *   that the query applies to for the interface on
1026 	 *   which the query arrived excl. those that belong
1027 	 *   to a "local" group (224.0.0.X)
1028 	 * - For timers already running check if they need to
1029 	 *   be reset.
1030 	 * - Use the igmp->igmp_code field as the maximum
1031 	 *   delay possible
1032 	 */
1033 	rcu_read_lock();
1034 	for_each_pmc_rcu(in_dev, im) {
1035 		int changed;
1036 
1037 		if (group && group != im->multiaddr)
1038 			continue;
1039 		if (im->multiaddr == IGMP_ALL_HOSTS)
1040 			continue;
1041 		if (ipv4_is_local_multicast(im->multiaddr) &&
1042 		    !net->ipv4.sysctl_igmp_llm_reports)
1043 			continue;
1044 		spin_lock_bh(&im->lock);
1045 		if (im->tm_running)
1046 			im->gsquery = im->gsquery && mark;
1047 		else
1048 			im->gsquery = mark;
1049 		changed = !im->gsquery ||
1050 			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
1051 		spin_unlock_bh(&im->lock);
1052 		if (changed)
1053 			igmp_mod_timer(im, max_delay);
1054 	}
1055 	rcu_read_unlock();
1056 	return false;
1057 }
1058 
1059 /* called in rcu_read_lock() section */
1060 int igmp_rcv(struct sk_buff *skb)
1061 {
1062 	/* This basically follows the spec line by line -- see RFC1112 */
1063 	struct igmphdr *ih;
1064 	struct net_device *dev = skb->dev;
1065 	struct in_device *in_dev;
1066 	int len = skb->len;
1067 	bool dropped = true;
1068 
1069 	if (netif_is_l3_master(dev)) {
1070 		dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
1071 		if (!dev)
1072 			goto drop;
1073 	}
1074 
1075 	in_dev = __in_dev_get_rcu(dev);
1076 	if (!in_dev)
1077 		goto drop;
1078 
1079 	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
1080 		goto drop;
1081 
1082 	if (skb_checksum_simple_validate(skb))
1083 		goto drop;
1084 
1085 	ih = igmp_hdr(skb);
1086 	switch (ih->type) {
1087 	case IGMP_HOST_MEMBERSHIP_QUERY:
1088 		dropped = igmp_heard_query(in_dev, skb, len);
1089 		break;
1090 	case IGMP_HOST_MEMBERSHIP_REPORT:
1091 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1092 		/* Is it our report looped back? */
1093 		if (rt_is_output_route(skb_rtable(skb)))
1094 			break;
1095 		/* don't rely on MC router hearing unicast reports */
1096 		if (skb->pkt_type == PACKET_MULTICAST ||
1097 		    skb->pkt_type == PACKET_BROADCAST)
1098 			dropped = igmp_heard_report(in_dev, ih->group);
1099 		break;
1100 	case IGMP_PIM:
1101 #ifdef CONFIG_IP_PIMSM_V1
1102 		return pim_rcv_v1(skb);
1103 #endif
1104 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1105 	case IGMP_DVMRP:
1106 	case IGMP_TRACE:
1107 	case IGMP_HOST_LEAVE_MESSAGE:
1108 	case IGMP_MTRACE:
1109 	case IGMP_MTRACE_RESP:
1110 		break;
1111 	default:
1112 		break;
1113 	}
1114 
1115 drop:
1116 	if (dropped)
1117 		kfree_skb(skb);
1118 	else
1119 		consume_skb(skb);
1120 	return 0;
1121 }
1122 
1123 #endif
1124 
1125 
1126 /*
1127  *	Add a filter to a device
1128  */
1129 
1130 static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
1131 {
1132 	char buf[MAX_ADDR_LEN];
1133 	struct net_device *dev = in_dev->dev;
1134 
1135 	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
1136 	   We will get multicast token leakage, when IFF_MULTICAST
1137 	   is changed. This check should be done in ndo_set_rx_mode
1138 	   routine. Something sort of:
1139 	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
1140 	   --ANK
1141 	   */
1142 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1143 		dev_mc_add(dev, buf);
1144 }
1145 
1146 /*
1147  *	Remove a filter from a device
1148  */
1149 
1150 static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
1151 {
1152 	char buf[MAX_ADDR_LEN];
1153 	struct net_device *dev = in_dev->dev;
1154 
1155 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1156 		dev_mc_del(dev, buf);
1157 }
1158 
1159 #ifdef CONFIG_IP_MULTICAST
1160 /*
1161  * deleted ip_mc_list manipulation
1162  */
1163 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
1164 			      gfp_t gfp)
1165 {
1166 	struct ip_mc_list *pmc;
1167 	struct net *net = dev_net(in_dev->dev);
1168 
1169 	/* this is an "ip_mc_list" for convenience; only the fields below
1170 	 * are actually used. In particular, the refcnt and users are not
1171 	 * used for management of the delete list. Using the same structure
1172 	 * for deleted items allows change reports to use common code with
1173 	 * non-deleted or query-response MCA's.
1174 	 */
1175 	pmc = kzalloc(sizeof(*pmc), gfp);
1176 	if (!pmc)
1177 		return;
1178 	spin_lock_init(&pmc->lock);
1179 	spin_lock_bh(&im->lock);
1180 	pmc->interface = im->interface;
1181 	in_dev_hold(in_dev);
1182 	pmc->multiaddr = im->multiaddr;
1183 	pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1184 	pmc->sfmode = im->sfmode;
1185 	if (pmc->sfmode == MCAST_INCLUDE) {
1186 		struct ip_sf_list *psf;
1187 
1188 		pmc->tomb = im->tomb;
1189 		pmc->sources = im->sources;
1190 		im->tomb = im->sources = NULL;
1191 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1192 			psf->sf_crcount = pmc->crcount;
1193 	}
1194 	spin_unlock_bh(&im->lock);
1195 
1196 	spin_lock_bh(&in_dev->mc_tomb_lock);
1197 	pmc->next = in_dev->mc_tomb;
1198 	in_dev->mc_tomb = pmc;
1199 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1200 }
1201 
1202 /*
1203  * restore ip_mc_list deleted records
1204  */
1205 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1206 {
1207 	struct ip_mc_list *pmc, *pmc_prev;
1208 	struct ip_sf_list *psf;
1209 	struct net *net = dev_net(in_dev->dev);
1210 	__be32 multiaddr = im->multiaddr;
1211 
1212 	spin_lock_bh(&in_dev->mc_tomb_lock);
1213 	pmc_prev = NULL;
1214 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
1215 		if (pmc->multiaddr == multiaddr)
1216 			break;
1217 		pmc_prev = pmc;
1218 	}
1219 	if (pmc) {
1220 		if (pmc_prev)
1221 			pmc_prev->next = pmc->next;
1222 		else
1223 			in_dev->mc_tomb = pmc->next;
1224 	}
1225 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1226 
1227 	spin_lock_bh(&im->lock);
1228 	if (pmc) {
1229 		im->interface = pmc->interface;
1230 		if (im->sfmode == MCAST_INCLUDE) {
1231 			im->tomb = pmc->tomb;
1232 			pmc->tomb = NULL;
1233 
1234 			im->sources = pmc->sources;
1235 			pmc->sources = NULL;
1236 
1237 			for (psf = im->sources; psf; psf = psf->sf_next)
1238 				psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1239 		} else {
1240 			im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1241 		}
1242 		in_dev_put(pmc->interface);
1243 		kfree_pmc(pmc);
1244 	}
1245 	spin_unlock_bh(&im->lock);
1246 }
1247 
1248 /*
1249  * flush ip_mc_list deleted records
1250  */
1251 static void igmpv3_clear_delrec(struct in_device *in_dev)
1252 {
1253 	struct ip_mc_list *pmc, *nextpmc;
1254 
1255 	spin_lock_bh(&in_dev->mc_tomb_lock);
1256 	pmc = in_dev->mc_tomb;
1257 	in_dev->mc_tomb = NULL;
1258 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1259 
1260 	for (; pmc; pmc = nextpmc) {
1261 		nextpmc = pmc->next;
1262 		ip_mc_clear_src(pmc);
1263 		in_dev_put(pmc->interface);
1264 		kfree_pmc(pmc);
1265 	}
1266 	/* clear dead sources, too */
1267 	rcu_read_lock();
1268 	for_each_pmc_rcu(in_dev, pmc) {
1269 		struct ip_sf_list *psf;
1270 
1271 		spin_lock_bh(&pmc->lock);
1272 		psf = pmc->tomb;
1273 		pmc->tomb = NULL;
1274 		spin_unlock_bh(&pmc->lock);
1275 		ip_sf_list_clear_all(psf);
1276 	}
1277 	rcu_read_unlock();
1278 }
1279 #endif
1280 
1281 static void __igmp_group_dropped(struct ip_mc_list *im, gfp_t gfp)
1282 {
1283 	struct in_device *in_dev = im->interface;
1284 #ifdef CONFIG_IP_MULTICAST
1285 	struct net *net = dev_net(in_dev->dev);
1286 	int reporter;
1287 #endif
1288 
1289 	if (im->loaded) {
1290 		im->loaded = 0;
1291 		ip_mc_filter_del(in_dev, im->multiaddr);
1292 	}
1293 
1294 #ifdef CONFIG_IP_MULTICAST
1295 	if (im->multiaddr == IGMP_ALL_HOSTS)
1296 		return;
1297 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1298 		return;
1299 
1300 	reporter = im->reporter;
1301 	igmp_stop_timer(im);
1302 
1303 	if (!in_dev->dead) {
1304 		if (IGMP_V1_SEEN(in_dev))
1305 			return;
1306 		if (IGMP_V2_SEEN(in_dev)) {
1307 			if (reporter)
1308 				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
1309 			return;
1310 		}
1311 		/* IGMPv3 */
1312 		igmpv3_add_delrec(in_dev, im, gfp);
1313 
1314 		igmp_ifc_event(in_dev);
1315 	}
1316 #endif
1317 }
1318 
1319 static void igmp_group_dropped(struct ip_mc_list *im)
1320 {
1321 	__igmp_group_dropped(im, GFP_KERNEL);
1322 }
1323 
1324 static void igmp_group_added(struct ip_mc_list *im)
1325 {
1326 	struct in_device *in_dev = im->interface;
1327 #ifdef CONFIG_IP_MULTICAST
1328 	struct net *net = dev_net(in_dev->dev);
1329 #endif
1330 
1331 	if (im->loaded == 0) {
1332 		im->loaded = 1;
1333 		ip_mc_filter_add(in_dev, im->multiaddr);
1334 	}
1335 
1336 #ifdef CONFIG_IP_MULTICAST
1337 	if (im->multiaddr == IGMP_ALL_HOSTS)
1338 		return;
1339 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1340 		return;
1341 
1342 	if (in_dev->dead)
1343 		return;
1344 
1345 	im->unsolicit_count = net->ipv4.sysctl_igmp_qrv;
1346 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
1347 		spin_lock_bh(&im->lock);
1348 		igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
1349 		spin_unlock_bh(&im->lock);
1350 		return;
1351 	}
1352 	/* else, v3 */
1353 
1354 	/* Based on RFC3376 5.1, for newly added INCLUDE SSM, we should
1355 	 * not send filter-mode change record as the mode should be from
1356 	 * IN() to IN(A).
1357 	 */
1358 	if (im->sfmode == MCAST_EXCLUDE)
1359 		im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1360 
1361 	igmp_ifc_event(in_dev);
1362 #endif
1363 }
1364 
1365 
1366 /*
1367  *	Multicast list managers
1368  */
1369 
1370 static u32 ip_mc_hash(const struct ip_mc_list *im)
1371 {
1372 	return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
1373 }
1374 
1375 static void ip_mc_hash_add(struct in_device *in_dev,
1376 			   struct ip_mc_list *im)
1377 {
1378 	struct ip_mc_list __rcu **mc_hash;
1379 	u32 hash;
1380 
1381 	mc_hash = rtnl_dereference(in_dev->mc_hash);
1382 	if (mc_hash) {
1383 		hash = ip_mc_hash(im);
1384 		im->next_hash = mc_hash[hash];
1385 		rcu_assign_pointer(mc_hash[hash], im);
1386 		return;
1387 	}
1388 
1389 	/* do not use a hash table for small number of items */
1390 	if (in_dev->mc_count < 4)
1391 		return;
1392 
1393 	mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
1394 			  GFP_KERNEL);
1395 	if (!mc_hash)
1396 		return;
1397 
1398 	for_each_pmc_rtnl(in_dev, im) {
1399 		hash = ip_mc_hash(im);
1400 		im->next_hash = mc_hash[hash];
1401 		RCU_INIT_POINTER(mc_hash[hash], im);
1402 	}
1403 
1404 	rcu_assign_pointer(in_dev->mc_hash, mc_hash);
1405 }
1406 
1407 static void ip_mc_hash_remove(struct in_device *in_dev,
1408 			      struct ip_mc_list *im)
1409 {
1410 	struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
1411 	struct ip_mc_list *aux;
1412 
1413 	if (!mc_hash)
1414 		return;
1415 	mc_hash += ip_mc_hash(im);
1416 	while ((aux = rtnl_dereference(*mc_hash)) != im)
1417 		mc_hash = &aux->next_hash;
1418 	*mc_hash = im->next_hash;
1419 }
1420 
1421 
1422 /*
1423  *	A socket has joined a multicast group on device dev.
1424  */
1425 static void ____ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
1426 				unsigned int mode, gfp_t gfp)
1427 {
1428 	struct ip_mc_list *im;
1429 
1430 	ASSERT_RTNL();
1431 
1432 	for_each_pmc_rtnl(in_dev, im) {
1433 		if (im->multiaddr == addr) {
1434 			im->users++;
1435 			ip_mc_add_src(in_dev, &addr, mode, 0, NULL, 0);
1436 			goto out;
1437 		}
1438 	}
1439 
1440 	im = kzalloc(sizeof(*im), gfp);
1441 	if (!im)
1442 		goto out;
1443 
1444 	im->users = 1;
1445 	im->interface = in_dev;
1446 	in_dev_hold(in_dev);
1447 	im->multiaddr = addr;
1448 	/* initial mode is (EX, empty) */
1449 	im->sfmode = mode;
1450 	im->sfcount[mode] = 1;
1451 	refcount_set(&im->refcnt, 1);
1452 	spin_lock_init(&im->lock);
1453 #ifdef CONFIG_IP_MULTICAST
1454 	timer_setup(&im->timer, igmp_timer_expire, 0);
1455 #endif
1456 
1457 	im->next_rcu = in_dev->mc_list;
1458 	in_dev->mc_count++;
1459 	rcu_assign_pointer(in_dev->mc_list, im);
1460 
1461 	ip_mc_hash_add(in_dev, im);
1462 
1463 #ifdef CONFIG_IP_MULTICAST
1464 	igmpv3_del_delrec(in_dev, im);
1465 #endif
1466 	igmp_group_added(im);
1467 	if (!in_dev->dead)
1468 		ip_rt_multicast_event(in_dev);
1469 out:
1470 	return;
1471 }
1472 
1473 void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
1474 {
1475 	____ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE, gfp);
1476 }
1477 EXPORT_SYMBOL(__ip_mc_inc_group);
1478 
1479 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
1480 {
1481 	__ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE);
1482 }
1483 EXPORT_SYMBOL(ip_mc_inc_group);
1484 
1485 static int ip_mc_check_iphdr(struct sk_buff *skb)
1486 {
1487 	const struct iphdr *iph;
1488 	unsigned int len;
1489 	unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
1490 
1491 	if (!pskb_may_pull(skb, offset))
1492 		return -EINVAL;
1493 
1494 	iph = ip_hdr(skb);
1495 
1496 	if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
1497 		return -EINVAL;
1498 
1499 	offset += ip_hdrlen(skb) - sizeof(*iph);
1500 
1501 	if (!pskb_may_pull(skb, offset))
1502 		return -EINVAL;
1503 
1504 	iph = ip_hdr(skb);
1505 
1506 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1507 		return -EINVAL;
1508 
1509 	len = skb_network_offset(skb) + ntohs(iph->tot_len);
1510 	if (skb->len < len || len < offset)
1511 		return -EINVAL;
1512 
1513 	skb_set_transport_header(skb, offset);
1514 
1515 	return 0;
1516 }
1517 
1518 static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
1519 {
1520 	unsigned int len = skb_transport_offset(skb);
1521 
1522 	len += sizeof(struct igmpv3_report);
1523 
1524 	return ip_mc_may_pull(skb, len) ? 0 : -EINVAL;
1525 }
1526 
1527 static int ip_mc_check_igmp_query(struct sk_buff *skb)
1528 {
1529 	unsigned int transport_len = ip_transport_len(skb);
1530 	unsigned int len;
1531 
1532 	/* IGMPv{1,2}? */
1533 	if (transport_len != sizeof(struct igmphdr)) {
1534 		/* or IGMPv3? */
1535 		if (transport_len < sizeof(struct igmpv3_query))
1536 			return -EINVAL;
1537 
1538 		len = skb_transport_offset(skb) + sizeof(struct igmpv3_query);
1539 		if (!ip_mc_may_pull(skb, len))
1540 			return -EINVAL;
1541 	}
1542 
1543 	/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
1544 	 * all-systems destination addresses (224.0.0.1) for general queries
1545 	 */
1546 	if (!igmp_hdr(skb)->group &&
1547 	    ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
1548 		return -EINVAL;
1549 
1550 	return 0;
1551 }
1552 
1553 static int ip_mc_check_igmp_msg(struct sk_buff *skb)
1554 {
1555 	switch (igmp_hdr(skb)->type) {
1556 	case IGMP_HOST_LEAVE_MESSAGE:
1557 	case IGMP_HOST_MEMBERSHIP_REPORT:
1558 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1559 		return 0;
1560 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1561 		return ip_mc_check_igmp_reportv3(skb);
1562 	case IGMP_HOST_MEMBERSHIP_QUERY:
1563 		return ip_mc_check_igmp_query(skb);
1564 	default:
1565 		return -ENOMSG;
1566 	}
1567 }
1568 
1569 static inline __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
1570 {
1571 	return skb_checksum_simple_validate(skb);
1572 }
1573 
1574 static int ip_mc_check_igmp_csum(struct sk_buff *skb)
1575 {
1576 	unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
1577 	unsigned int transport_len = ip_transport_len(skb);
1578 	struct sk_buff *skb_chk;
1579 
1580 	if (!ip_mc_may_pull(skb, len))
1581 		return -EINVAL;
1582 
1583 	skb_chk = skb_checksum_trimmed(skb, transport_len,
1584 				       ip_mc_validate_checksum);
1585 	if (!skb_chk)
1586 		return -EINVAL;
1587 
1588 	if (skb_chk != skb)
1589 		kfree_skb(skb_chk);
1590 
1591 	return 0;
1592 }
1593 
1594 /**
1595  * ip_mc_check_igmp - checks whether this is a sane IGMP packet
1596  * @skb: the skb to validate
1597  *
1598  * Checks whether an IPv4 packet is a valid IGMP packet. If so sets
1599  * skb transport header accordingly and returns zero.
1600  *
1601  * -EINVAL: A broken packet was detected, i.e. it violates some internet
1602  *  standard
1603  * -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
1604  * -ENOMEM: A memory allocation failure happened.
1605  *
1606  * Caller needs to set the skb network header and free any returned skb if it
1607  * differs from the provided skb.
1608  */
1609 int ip_mc_check_igmp(struct sk_buff *skb)
1610 {
1611 	int ret = ip_mc_check_iphdr(skb);
1612 
1613 	if (ret < 0)
1614 		return ret;
1615 
1616 	if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
1617 		return -ENOMSG;
1618 
1619 	ret = ip_mc_check_igmp_csum(skb);
1620 	if (ret < 0)
1621 		return ret;
1622 
1623 	return ip_mc_check_igmp_msg(skb);
1624 }
1625 EXPORT_SYMBOL(ip_mc_check_igmp);
1626 
1627 /*
1628  *	Resend IGMP JOIN report; used by netdev notifier.
1629  */
1630 static void ip_mc_rejoin_groups(struct in_device *in_dev)
1631 {
1632 #ifdef CONFIG_IP_MULTICAST
1633 	struct ip_mc_list *im;
1634 	int type;
1635 	struct net *net = dev_net(in_dev->dev);
1636 
1637 	ASSERT_RTNL();
1638 
1639 	for_each_pmc_rtnl(in_dev, im) {
1640 		if (im->multiaddr == IGMP_ALL_HOSTS)
1641 			continue;
1642 		if (ipv4_is_local_multicast(im->multiaddr) &&
1643 		    !net->ipv4.sysctl_igmp_llm_reports)
1644 			continue;
1645 
1646 		/* a failover is happening and switches
1647 		 * must be notified immediately
1648 		 */
1649 		if (IGMP_V1_SEEN(in_dev))
1650 			type = IGMP_HOST_MEMBERSHIP_REPORT;
1651 		else if (IGMP_V2_SEEN(in_dev))
1652 			type = IGMPV2_HOST_MEMBERSHIP_REPORT;
1653 		else
1654 			type = IGMPV3_HOST_MEMBERSHIP_REPORT;
1655 		igmp_send_report(in_dev, im, type);
1656 	}
1657 #endif
1658 }
1659 
1660 /*
1661  *	A socket has left a multicast group on device dev
1662  */
1663 
1664 void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
1665 {
1666 	struct ip_mc_list *i;
1667 	struct ip_mc_list __rcu **ip;
1668 
1669 	ASSERT_RTNL();
1670 
1671 	for (ip = &in_dev->mc_list;
1672 	     (i = rtnl_dereference(*ip)) != NULL;
1673 	     ip = &i->next_rcu) {
1674 		if (i->multiaddr == addr) {
1675 			if (--i->users == 0) {
1676 				ip_mc_hash_remove(in_dev, i);
1677 				*ip = i->next_rcu;
1678 				in_dev->mc_count--;
1679 				__igmp_group_dropped(i, gfp);
1680 				ip_mc_clear_src(i);
1681 
1682 				if (!in_dev->dead)
1683 					ip_rt_multicast_event(in_dev);
1684 
1685 				ip_ma_put(i);
1686 				return;
1687 			}
1688 			break;
1689 		}
1690 	}
1691 }
1692 EXPORT_SYMBOL(__ip_mc_dec_group);
1693 
1694 /* Device changing type */
1695 
1696 void ip_mc_unmap(struct in_device *in_dev)
1697 {
1698 	struct ip_mc_list *pmc;
1699 
1700 	ASSERT_RTNL();
1701 
1702 	for_each_pmc_rtnl(in_dev, pmc)
1703 		igmp_group_dropped(pmc);
1704 }
1705 
1706 void ip_mc_remap(struct in_device *in_dev)
1707 {
1708 	struct ip_mc_list *pmc;
1709 
1710 	ASSERT_RTNL();
1711 
1712 	for_each_pmc_rtnl(in_dev, pmc) {
1713 #ifdef CONFIG_IP_MULTICAST
1714 		igmpv3_del_delrec(in_dev, pmc);
1715 #endif
1716 		igmp_group_added(pmc);
1717 	}
1718 }
1719 
1720 /* Device going down */
1721 
1722 void ip_mc_down(struct in_device *in_dev)
1723 {
1724 	struct ip_mc_list *pmc;
1725 
1726 	ASSERT_RTNL();
1727 
1728 	for_each_pmc_rtnl(in_dev, pmc)
1729 		igmp_group_dropped(pmc);
1730 
1731 #ifdef CONFIG_IP_MULTICAST
1732 	in_dev->mr_ifc_count = 0;
1733 	if (del_timer(&in_dev->mr_ifc_timer))
1734 		__in_dev_put(in_dev);
1735 	in_dev->mr_gq_running = 0;
1736 	if (del_timer(&in_dev->mr_gq_timer))
1737 		__in_dev_put(in_dev);
1738 #endif
1739 
1740 	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
1741 }
1742 
1743 #ifdef CONFIG_IP_MULTICAST
1744 static void ip_mc_reset(struct in_device *in_dev)
1745 {
1746 	struct net *net = dev_net(in_dev->dev);
1747 
1748 	in_dev->mr_qi = IGMP_QUERY_INTERVAL;
1749 	in_dev->mr_qri = IGMP_QUERY_RESPONSE_INTERVAL;
1750 	in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
1751 }
1752 #else
1753 static void ip_mc_reset(struct in_device *in_dev)
1754 {
1755 }
1756 #endif
1757 
1758 void ip_mc_init_dev(struct in_device *in_dev)
1759 {
1760 	ASSERT_RTNL();
1761 
1762 #ifdef CONFIG_IP_MULTICAST
1763 	timer_setup(&in_dev->mr_gq_timer, igmp_gq_timer_expire, 0);
1764 	timer_setup(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire, 0);
1765 #endif
1766 	ip_mc_reset(in_dev);
1767 
1768 	spin_lock_init(&in_dev->mc_tomb_lock);
1769 }
1770 
1771 /* Device going up */
1772 
1773 void ip_mc_up(struct in_device *in_dev)
1774 {
1775 	struct ip_mc_list *pmc;
1776 
1777 	ASSERT_RTNL();
1778 
1779 	ip_mc_reset(in_dev);
1780 	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
1781 
1782 	for_each_pmc_rtnl(in_dev, pmc) {
1783 #ifdef CONFIG_IP_MULTICAST
1784 		igmpv3_del_delrec(in_dev, pmc);
1785 #endif
1786 		igmp_group_added(pmc);
1787 	}
1788 }
1789 
1790 /*
1791  *	Device is about to be destroyed: clean up.
1792  */
1793 
1794 void ip_mc_destroy_dev(struct in_device *in_dev)
1795 {
1796 	struct ip_mc_list *i;
1797 
1798 	ASSERT_RTNL();
1799 
1800 	/* Deactivate timers */
1801 	ip_mc_down(in_dev);
1802 #ifdef CONFIG_IP_MULTICAST
1803 	igmpv3_clear_delrec(in_dev);
1804 #endif
1805 
1806 	while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
1807 		in_dev->mc_list = i->next_rcu;
1808 		in_dev->mc_count--;
1809 		ip_ma_put(i);
1810 	}
1811 }
1812 
1813 /* RTNL is locked */
1814 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1815 {
1816 	struct net_device *dev = NULL;
1817 	struct in_device *idev = NULL;
1818 
1819 	if (imr->imr_ifindex) {
1820 		idev = inetdev_by_index(net, imr->imr_ifindex);
1821 		return idev;
1822 	}
1823 	if (imr->imr_address.s_addr) {
1824 		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1825 		if (!dev)
1826 			return NULL;
1827 	}
1828 
1829 	if (!dev) {
1830 		struct rtable *rt = ip_route_output(net,
1831 						    imr->imr_multiaddr.s_addr,
1832 						    0, 0, 0);
1833 		if (!IS_ERR(rt)) {
1834 			dev = rt->dst.dev;
1835 			ip_rt_put(rt);
1836 		}
1837 	}
1838 	if (dev) {
1839 		imr->imr_ifindex = dev->ifindex;
1840 		idev = __in_dev_get_rtnl(dev);
1841 	}
1842 	return idev;
1843 }
1844 
1845 /*
1846  *	Join a socket to a group
1847  */
1848 
1849 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1850 	__be32 *psfsrc)
1851 {
1852 	struct ip_sf_list *psf, *psf_prev;
1853 	int rv = 0;
1854 
1855 	psf_prev = NULL;
1856 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1857 		if (psf->sf_inaddr == *psfsrc)
1858 			break;
1859 		psf_prev = psf;
1860 	}
1861 	if (!psf || psf->sf_count[sfmode] == 0) {
1862 		/* source filter not found, or count wrong =>  bug */
1863 		return -ESRCH;
1864 	}
1865 	psf->sf_count[sfmode]--;
1866 	if (psf->sf_count[sfmode] == 0) {
1867 		ip_rt_multicast_event(pmc->interface);
1868 	}
1869 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1870 #ifdef CONFIG_IP_MULTICAST
1871 		struct in_device *in_dev = pmc->interface;
1872 		struct net *net = dev_net(in_dev->dev);
1873 #endif
1874 
1875 		/* no more filters for this source */
1876 		if (psf_prev)
1877 			psf_prev->sf_next = psf->sf_next;
1878 		else
1879 			pmc->sources = psf->sf_next;
1880 #ifdef CONFIG_IP_MULTICAST
1881 		if (psf->sf_oldin &&
1882 		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1883 			psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1884 			psf->sf_next = pmc->tomb;
1885 			pmc->tomb = psf;
1886 			rv = 1;
1887 		} else
1888 #endif
1889 			kfree(psf);
1890 	}
1891 	return rv;
1892 }
1893 
1894 #ifndef CONFIG_IP_MULTICAST
1895 #define igmp_ifc_event(x)	do { } while (0)
1896 #endif
1897 
1898 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1899 			 int sfcount, __be32 *psfsrc, int delta)
1900 {
1901 	struct ip_mc_list *pmc;
1902 	int	changerec = 0;
1903 	int	i, err;
1904 
1905 	if (!in_dev)
1906 		return -ENODEV;
1907 	rcu_read_lock();
1908 	for_each_pmc_rcu(in_dev, pmc) {
1909 		if (*pmca == pmc->multiaddr)
1910 			break;
1911 	}
1912 	if (!pmc) {
1913 		/* MCA not found?? bug */
1914 		rcu_read_unlock();
1915 		return -ESRCH;
1916 	}
1917 	spin_lock_bh(&pmc->lock);
1918 	rcu_read_unlock();
1919 #ifdef CONFIG_IP_MULTICAST
1920 	sf_markstate(pmc);
1921 #endif
1922 	if (!delta) {
1923 		err = -EINVAL;
1924 		if (!pmc->sfcount[sfmode])
1925 			goto out_unlock;
1926 		pmc->sfcount[sfmode]--;
1927 	}
1928 	err = 0;
1929 	for (i = 0; i < sfcount; i++) {
1930 		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1931 
1932 		changerec |= rv > 0;
1933 		if (!err && rv < 0)
1934 			err = rv;
1935 	}
1936 	if (pmc->sfmode == MCAST_EXCLUDE &&
1937 	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1938 	    pmc->sfcount[MCAST_INCLUDE]) {
1939 #ifdef CONFIG_IP_MULTICAST
1940 		struct ip_sf_list *psf;
1941 		struct net *net = dev_net(in_dev->dev);
1942 #endif
1943 
1944 		/* filter mode change */
1945 		pmc->sfmode = MCAST_INCLUDE;
1946 #ifdef CONFIG_IP_MULTICAST
1947 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1948 		in_dev->mr_ifc_count = pmc->crcount;
1949 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1950 			psf->sf_crcount = 0;
1951 		igmp_ifc_event(pmc->interface);
1952 	} else if (sf_setstate(pmc) || changerec) {
1953 		igmp_ifc_event(pmc->interface);
1954 #endif
1955 	}
1956 out_unlock:
1957 	spin_unlock_bh(&pmc->lock);
1958 	return err;
1959 }
1960 
1961 /*
1962  * Add multicast single-source filter to the interface list
1963  */
1964 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1965 	__be32 *psfsrc)
1966 {
1967 	struct ip_sf_list *psf, *psf_prev;
1968 
1969 	psf_prev = NULL;
1970 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1971 		if (psf->sf_inaddr == *psfsrc)
1972 			break;
1973 		psf_prev = psf;
1974 	}
1975 	if (!psf) {
1976 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1977 		if (!psf)
1978 			return -ENOBUFS;
1979 		psf->sf_inaddr = *psfsrc;
1980 		if (psf_prev) {
1981 			psf_prev->sf_next = psf;
1982 		} else
1983 			pmc->sources = psf;
1984 	}
1985 	psf->sf_count[sfmode]++;
1986 	if (psf->sf_count[sfmode] == 1) {
1987 		ip_rt_multicast_event(pmc->interface);
1988 	}
1989 	return 0;
1990 }
1991 
1992 #ifdef CONFIG_IP_MULTICAST
1993 static void sf_markstate(struct ip_mc_list *pmc)
1994 {
1995 	struct ip_sf_list *psf;
1996 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1997 
1998 	for (psf = pmc->sources; psf; psf = psf->sf_next)
1999 		if (pmc->sfcount[MCAST_EXCLUDE]) {
2000 			psf->sf_oldin = mca_xcount ==
2001 				psf->sf_count[MCAST_EXCLUDE] &&
2002 				!psf->sf_count[MCAST_INCLUDE];
2003 		} else
2004 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
2005 }
2006 
2007 static int sf_setstate(struct ip_mc_list *pmc)
2008 {
2009 	struct ip_sf_list *psf, *dpsf;
2010 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
2011 	int qrv = pmc->interface->mr_qrv;
2012 	int new_in, rv;
2013 
2014 	rv = 0;
2015 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
2016 		if (pmc->sfcount[MCAST_EXCLUDE]) {
2017 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
2018 				!psf->sf_count[MCAST_INCLUDE];
2019 		} else
2020 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
2021 		if (new_in) {
2022 			if (!psf->sf_oldin) {
2023 				struct ip_sf_list *prev = NULL;
2024 
2025 				for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
2026 					if (dpsf->sf_inaddr == psf->sf_inaddr)
2027 						break;
2028 					prev = dpsf;
2029 				}
2030 				if (dpsf) {
2031 					if (prev)
2032 						prev->sf_next = dpsf->sf_next;
2033 					else
2034 						pmc->tomb = dpsf->sf_next;
2035 					kfree(dpsf);
2036 				}
2037 				psf->sf_crcount = qrv;
2038 				rv++;
2039 			}
2040 		} else if (psf->sf_oldin) {
2041 
2042 			psf->sf_crcount = 0;
2043 			/*
2044 			 * add or update "delete" records if an active filter
2045 			 * is now inactive
2046 			 */
2047 			for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
2048 				if (dpsf->sf_inaddr == psf->sf_inaddr)
2049 					break;
2050 			if (!dpsf) {
2051 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
2052 				if (!dpsf)
2053 					continue;
2054 				*dpsf = *psf;
2055 				/* pmc->lock held by callers */
2056 				dpsf->sf_next = pmc->tomb;
2057 				pmc->tomb = dpsf;
2058 			}
2059 			dpsf->sf_crcount = qrv;
2060 			rv++;
2061 		}
2062 	}
2063 	return rv;
2064 }
2065 #endif
2066 
2067 /*
2068  * Add multicast source filter list to the interface list
2069  */
2070 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
2071 			 int sfcount, __be32 *psfsrc, int delta)
2072 {
2073 	struct ip_mc_list *pmc;
2074 	int	isexclude;
2075 	int	i, err;
2076 
2077 	if (!in_dev)
2078 		return -ENODEV;
2079 	rcu_read_lock();
2080 	for_each_pmc_rcu(in_dev, pmc) {
2081 		if (*pmca == pmc->multiaddr)
2082 			break;
2083 	}
2084 	if (!pmc) {
2085 		/* MCA not found?? bug */
2086 		rcu_read_unlock();
2087 		return -ESRCH;
2088 	}
2089 	spin_lock_bh(&pmc->lock);
2090 	rcu_read_unlock();
2091 
2092 #ifdef CONFIG_IP_MULTICAST
2093 	sf_markstate(pmc);
2094 #endif
2095 	isexclude = pmc->sfmode == MCAST_EXCLUDE;
2096 	if (!delta)
2097 		pmc->sfcount[sfmode]++;
2098 	err = 0;
2099 	for (i = 0; i < sfcount; i++) {
2100 		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2101 		if (err)
2102 			break;
2103 	}
2104 	if (err) {
2105 		int j;
2106 
2107 		if (!delta)
2108 			pmc->sfcount[sfmode]--;
2109 		for (j = 0; j < i; j++)
2110 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2111 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
2112 #ifdef CONFIG_IP_MULTICAST
2113 		struct ip_sf_list *psf;
2114 		struct net *net = dev_net(pmc->interface->dev);
2115 		in_dev = pmc->interface;
2116 #endif
2117 
2118 		/* filter mode change */
2119 		if (pmc->sfcount[MCAST_EXCLUDE])
2120 			pmc->sfmode = MCAST_EXCLUDE;
2121 		else if (pmc->sfcount[MCAST_INCLUDE])
2122 			pmc->sfmode = MCAST_INCLUDE;
2123 #ifdef CONFIG_IP_MULTICAST
2124 		/* else no filters; keep old mode for reports */
2125 
2126 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
2127 		in_dev->mr_ifc_count = pmc->crcount;
2128 		for (psf = pmc->sources; psf; psf = psf->sf_next)
2129 			psf->sf_crcount = 0;
2130 		igmp_ifc_event(in_dev);
2131 	} else if (sf_setstate(pmc)) {
2132 		igmp_ifc_event(in_dev);
2133 #endif
2134 	}
2135 	spin_unlock_bh(&pmc->lock);
2136 	return err;
2137 }
2138 
2139 static void ip_mc_clear_src(struct ip_mc_list *pmc)
2140 {
2141 	struct ip_sf_list *tomb, *sources;
2142 
2143 	spin_lock_bh(&pmc->lock);
2144 	tomb = pmc->tomb;
2145 	pmc->tomb = NULL;
2146 	sources = pmc->sources;
2147 	pmc->sources = NULL;
2148 	pmc->sfmode = MCAST_EXCLUDE;
2149 	pmc->sfcount[MCAST_INCLUDE] = 0;
2150 	pmc->sfcount[MCAST_EXCLUDE] = 1;
2151 	spin_unlock_bh(&pmc->lock);
2152 
2153 	ip_sf_list_clear_all(tomb);
2154 	ip_sf_list_clear_all(sources);
2155 }
2156 
2157 /* Join a multicast group
2158  */
2159 static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
2160 			      unsigned int mode)
2161 {
2162 	__be32 addr = imr->imr_multiaddr.s_addr;
2163 	struct ip_mc_socklist *iml, *i;
2164 	struct in_device *in_dev;
2165 	struct inet_sock *inet = inet_sk(sk);
2166 	struct net *net = sock_net(sk);
2167 	int ifindex;
2168 	int count = 0;
2169 	int err;
2170 
2171 	ASSERT_RTNL();
2172 
2173 	if (!ipv4_is_multicast(addr))
2174 		return -EINVAL;
2175 
2176 	in_dev = ip_mc_find_dev(net, imr);
2177 
2178 	if (!in_dev) {
2179 		err = -ENODEV;
2180 		goto done;
2181 	}
2182 
2183 	err = -EADDRINUSE;
2184 	ifindex = imr->imr_ifindex;
2185 	for_each_pmc_rtnl(inet, i) {
2186 		if (i->multi.imr_multiaddr.s_addr == addr &&
2187 		    i->multi.imr_ifindex == ifindex)
2188 			goto done;
2189 		count++;
2190 	}
2191 	err = -ENOBUFS;
2192 	if (count >= net->ipv4.sysctl_igmp_max_memberships)
2193 		goto done;
2194 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
2195 	if (!iml)
2196 		goto done;
2197 
2198 	memcpy(&iml->multi, imr, sizeof(*imr));
2199 	iml->next_rcu = inet->mc_list;
2200 	iml->sflist = NULL;
2201 	iml->sfmode = mode;
2202 	rcu_assign_pointer(inet->mc_list, iml);
2203 	__ip_mc_inc_group(in_dev, addr, mode);
2204 	err = 0;
2205 done:
2206 	return err;
2207 }
2208 
2209 /* Join ASM (Any-Source Multicast) group
2210  */
2211 int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
2212 {
2213 	return __ip_mc_join_group(sk, imr, MCAST_EXCLUDE);
2214 }
2215 EXPORT_SYMBOL(ip_mc_join_group);
2216 
2217 /* Join SSM (Source-Specific Multicast) group
2218  */
2219 int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
2220 			 unsigned int mode)
2221 {
2222 	return __ip_mc_join_group(sk, imr, mode);
2223 }
2224 
2225 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
2226 			   struct in_device *in_dev)
2227 {
2228 	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
2229 	int err;
2230 
2231 	if (!psf) {
2232 		/* any-source empty exclude case */
2233 		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2234 			iml->sfmode, 0, NULL, 0);
2235 	}
2236 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2237 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
2238 	RCU_INIT_POINTER(iml->sflist, NULL);
2239 	/* decrease mem now to avoid the memleak warning */
2240 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
2241 	kfree_rcu(psf, rcu);
2242 	return err;
2243 }
2244 
2245 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
2246 {
2247 	struct inet_sock *inet = inet_sk(sk);
2248 	struct ip_mc_socklist *iml;
2249 	struct ip_mc_socklist __rcu **imlp;
2250 	struct in_device *in_dev;
2251 	struct net *net = sock_net(sk);
2252 	__be32 group = imr->imr_multiaddr.s_addr;
2253 	u32 ifindex;
2254 	int ret = -EADDRNOTAVAIL;
2255 
2256 	ASSERT_RTNL();
2257 
2258 	in_dev = ip_mc_find_dev(net, imr);
2259 	if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
2260 		ret = -ENODEV;
2261 		goto out;
2262 	}
2263 	ifindex = imr->imr_ifindex;
2264 	for (imlp = &inet->mc_list;
2265 	     (iml = rtnl_dereference(*imlp)) != NULL;
2266 	     imlp = &iml->next_rcu) {
2267 		if (iml->multi.imr_multiaddr.s_addr != group)
2268 			continue;
2269 		if (ifindex) {
2270 			if (iml->multi.imr_ifindex != ifindex)
2271 				continue;
2272 		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
2273 				iml->multi.imr_address.s_addr)
2274 			continue;
2275 
2276 		(void) ip_mc_leave_src(sk, iml, in_dev);
2277 
2278 		*imlp = iml->next_rcu;
2279 
2280 		if (in_dev)
2281 			ip_mc_dec_group(in_dev, group);
2282 
2283 		/* decrease mem now to avoid the memleak warning */
2284 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2285 		kfree_rcu(iml, rcu);
2286 		return 0;
2287 	}
2288 out:
2289 	return ret;
2290 }
2291 EXPORT_SYMBOL(ip_mc_leave_group);
2292 
2293 int ip_mc_source(int add, int omode, struct sock *sk, struct
2294 	ip_mreq_source *mreqs, int ifindex)
2295 {
2296 	int err;
2297 	struct ip_mreqn imr;
2298 	__be32 addr = mreqs->imr_multiaddr;
2299 	struct ip_mc_socklist *pmc;
2300 	struct in_device *in_dev = NULL;
2301 	struct inet_sock *inet = inet_sk(sk);
2302 	struct ip_sf_socklist *psl;
2303 	struct net *net = sock_net(sk);
2304 	int leavegroup = 0;
2305 	int i, j, rv;
2306 
2307 	if (!ipv4_is_multicast(addr))
2308 		return -EINVAL;
2309 
2310 	ASSERT_RTNL();
2311 
2312 	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
2313 	imr.imr_address.s_addr = mreqs->imr_interface;
2314 	imr.imr_ifindex = ifindex;
2315 	in_dev = ip_mc_find_dev(net, &imr);
2316 
2317 	if (!in_dev) {
2318 		err = -ENODEV;
2319 		goto done;
2320 	}
2321 	err = -EADDRNOTAVAIL;
2322 
2323 	for_each_pmc_rtnl(inet, pmc) {
2324 		if ((pmc->multi.imr_multiaddr.s_addr ==
2325 		     imr.imr_multiaddr.s_addr) &&
2326 		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
2327 			break;
2328 	}
2329 	if (!pmc) {		/* must have a prior join */
2330 		err = -EINVAL;
2331 		goto done;
2332 	}
2333 	/* if a source filter was set, must be the same mode as before */
2334 	if (pmc->sflist) {
2335 		if (pmc->sfmode != omode) {
2336 			err = -EINVAL;
2337 			goto done;
2338 		}
2339 	} else if (pmc->sfmode != omode) {
2340 		/* allow mode switches for empty-set filters */
2341 		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2342 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2343 			NULL, 0);
2344 		pmc->sfmode = omode;
2345 	}
2346 
2347 	psl = rtnl_dereference(pmc->sflist);
2348 	if (!add) {
2349 		if (!psl)
2350 			goto done;	/* err = -EADDRNOTAVAIL */
2351 		rv = !0;
2352 		for (i = 0; i < psl->sl_count; i++) {
2353 			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2354 				sizeof(__be32));
2355 			if (rv == 0)
2356 				break;
2357 		}
2358 		if (rv)		/* source not found */
2359 			goto done;	/* err = -EADDRNOTAVAIL */
2360 
2361 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2362 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2363 			leavegroup = 1;
2364 			goto done;
2365 		}
2366 
2367 		/* update the interface filter */
2368 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2369 			&mreqs->imr_sourceaddr, 1);
2370 
2371 		for (j = i+1; j < psl->sl_count; j++)
2372 			psl->sl_addr[j-1] = psl->sl_addr[j];
2373 		psl->sl_count--;
2374 		err = 0;
2375 		goto done;
2376 	}
2377 	/* else, add a new source to the filter */
2378 
2379 	if (psl && psl->sl_count >= net->ipv4.sysctl_igmp_max_msf) {
2380 		err = -ENOBUFS;
2381 		goto done;
2382 	}
2383 	if (!psl || psl->sl_count == psl->sl_max) {
2384 		struct ip_sf_socklist *newpsl;
2385 		int count = IP_SFBLOCK;
2386 
2387 		if (psl)
2388 			count += psl->sl_max;
2389 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2390 		if (!newpsl) {
2391 			err = -ENOBUFS;
2392 			goto done;
2393 		}
2394 		newpsl->sl_max = count;
2395 		newpsl->sl_count = count - IP_SFBLOCK;
2396 		if (psl) {
2397 			for (i = 0; i < psl->sl_count; i++)
2398 				newpsl->sl_addr[i] = psl->sl_addr[i];
2399 			/* decrease mem now to avoid the memleak warning */
2400 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2401 			kfree_rcu(psl, rcu);
2402 		}
2403 		rcu_assign_pointer(pmc->sflist, newpsl);
2404 		psl = newpsl;
2405 	}
2406 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
2407 	for (i = 0; i < psl->sl_count; i++) {
2408 		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2409 			sizeof(__be32));
2410 		if (rv == 0)
2411 			break;
2412 	}
2413 	if (rv == 0)		/* address already there is an error */
2414 		goto done;
2415 	for (j = psl->sl_count-1; j >= i; j--)
2416 		psl->sl_addr[j+1] = psl->sl_addr[j];
2417 	psl->sl_addr[i] = mreqs->imr_sourceaddr;
2418 	psl->sl_count++;
2419 	err = 0;
2420 	/* update the interface list */
2421 	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2422 		&mreqs->imr_sourceaddr, 1);
2423 done:
2424 	if (leavegroup)
2425 		err = ip_mc_leave_group(sk, &imr);
2426 	return err;
2427 }
2428 
2429 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2430 {
2431 	int err = 0;
2432 	struct ip_mreqn	imr;
2433 	__be32 addr = msf->imsf_multiaddr;
2434 	struct ip_mc_socklist *pmc;
2435 	struct in_device *in_dev;
2436 	struct inet_sock *inet = inet_sk(sk);
2437 	struct ip_sf_socklist *newpsl, *psl;
2438 	struct net *net = sock_net(sk);
2439 	int leavegroup = 0;
2440 
2441 	if (!ipv4_is_multicast(addr))
2442 		return -EINVAL;
2443 	if (msf->imsf_fmode != MCAST_INCLUDE &&
2444 	    msf->imsf_fmode != MCAST_EXCLUDE)
2445 		return -EINVAL;
2446 
2447 	ASSERT_RTNL();
2448 
2449 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2450 	imr.imr_address.s_addr = msf->imsf_interface;
2451 	imr.imr_ifindex = ifindex;
2452 	in_dev = ip_mc_find_dev(net, &imr);
2453 
2454 	if (!in_dev) {
2455 		err = -ENODEV;
2456 		goto done;
2457 	}
2458 
2459 	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2460 	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2461 		leavegroup = 1;
2462 		goto done;
2463 	}
2464 
2465 	for_each_pmc_rtnl(inet, pmc) {
2466 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2467 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2468 			break;
2469 	}
2470 	if (!pmc) {		/* must have a prior join */
2471 		err = -EINVAL;
2472 		goto done;
2473 	}
2474 	if (msf->imsf_numsrc) {
2475 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2476 							   GFP_KERNEL);
2477 		if (!newpsl) {
2478 			err = -ENOBUFS;
2479 			goto done;
2480 		}
2481 		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2482 		memcpy(newpsl->sl_addr, msf->imsf_slist,
2483 			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2484 		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2485 			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2486 		if (err) {
2487 			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2488 			goto done;
2489 		}
2490 	} else {
2491 		newpsl = NULL;
2492 		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2493 				     msf->imsf_fmode, 0, NULL, 0);
2494 	}
2495 	psl = rtnl_dereference(pmc->sflist);
2496 	if (psl) {
2497 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2498 			psl->sl_count, psl->sl_addr, 0);
2499 		/* decrease mem now to avoid the memleak warning */
2500 		atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2501 		kfree_rcu(psl, rcu);
2502 	} else
2503 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2504 			0, NULL, 0);
2505 	rcu_assign_pointer(pmc->sflist, newpsl);
2506 	pmc->sfmode = msf->imsf_fmode;
2507 	err = 0;
2508 done:
2509 	if (leavegroup)
2510 		err = ip_mc_leave_group(sk, &imr);
2511 	return err;
2512 }
2513 
2514 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2515 	struct ip_msfilter __user *optval, int __user *optlen)
2516 {
2517 	int err, len, count, copycount;
2518 	struct ip_mreqn	imr;
2519 	__be32 addr = msf->imsf_multiaddr;
2520 	struct ip_mc_socklist *pmc;
2521 	struct in_device *in_dev;
2522 	struct inet_sock *inet = inet_sk(sk);
2523 	struct ip_sf_socklist *psl;
2524 	struct net *net = sock_net(sk);
2525 
2526 	ASSERT_RTNL();
2527 
2528 	if (!ipv4_is_multicast(addr))
2529 		return -EINVAL;
2530 
2531 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2532 	imr.imr_address.s_addr = msf->imsf_interface;
2533 	imr.imr_ifindex = 0;
2534 	in_dev = ip_mc_find_dev(net, &imr);
2535 
2536 	if (!in_dev) {
2537 		err = -ENODEV;
2538 		goto done;
2539 	}
2540 	err = -EADDRNOTAVAIL;
2541 
2542 	for_each_pmc_rtnl(inet, pmc) {
2543 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2544 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2545 			break;
2546 	}
2547 	if (!pmc)		/* must have a prior join */
2548 		goto done;
2549 	msf->imsf_fmode = pmc->sfmode;
2550 	psl = rtnl_dereference(pmc->sflist);
2551 	if (!psl) {
2552 		len = 0;
2553 		count = 0;
2554 	} else {
2555 		count = psl->sl_count;
2556 	}
2557 	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2558 	len = copycount * sizeof(psl->sl_addr[0]);
2559 	msf->imsf_numsrc = count;
2560 	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2561 	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2562 		return -EFAULT;
2563 	}
2564 	if (len &&
2565 	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2566 		return -EFAULT;
2567 	return 0;
2568 done:
2569 	return err;
2570 }
2571 
2572 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2573 	struct group_filter __user *optval, int __user *optlen)
2574 {
2575 	int err, i, count, copycount;
2576 	struct sockaddr_in *psin;
2577 	__be32 addr;
2578 	struct ip_mc_socklist *pmc;
2579 	struct inet_sock *inet = inet_sk(sk);
2580 	struct ip_sf_socklist *psl;
2581 
2582 	ASSERT_RTNL();
2583 
2584 	psin = (struct sockaddr_in *)&gsf->gf_group;
2585 	if (psin->sin_family != AF_INET)
2586 		return -EINVAL;
2587 	addr = psin->sin_addr.s_addr;
2588 	if (!ipv4_is_multicast(addr))
2589 		return -EINVAL;
2590 
2591 	err = -EADDRNOTAVAIL;
2592 
2593 	for_each_pmc_rtnl(inet, pmc) {
2594 		if (pmc->multi.imr_multiaddr.s_addr == addr &&
2595 		    pmc->multi.imr_ifindex == gsf->gf_interface)
2596 			break;
2597 	}
2598 	if (!pmc)		/* must have a prior join */
2599 		goto done;
2600 	gsf->gf_fmode = pmc->sfmode;
2601 	psl = rtnl_dereference(pmc->sflist);
2602 	count = psl ? psl->sl_count : 0;
2603 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2604 	gsf->gf_numsrc = count;
2605 	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
2606 	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
2607 		return -EFAULT;
2608 	}
2609 	for (i = 0; i < copycount; i++) {
2610 		struct sockaddr_storage ss;
2611 
2612 		psin = (struct sockaddr_in *)&ss;
2613 		memset(&ss, 0, sizeof(ss));
2614 		psin->sin_family = AF_INET;
2615 		psin->sin_addr.s_addr = psl->sl_addr[i];
2616 		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
2617 			return -EFAULT;
2618 	}
2619 	return 0;
2620 done:
2621 	return err;
2622 }
2623 
2624 /*
2625  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2626  */
2627 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
2628 		   int dif, int sdif)
2629 {
2630 	struct inet_sock *inet = inet_sk(sk);
2631 	struct ip_mc_socklist *pmc;
2632 	struct ip_sf_socklist *psl;
2633 	int i;
2634 	int ret;
2635 
2636 	ret = 1;
2637 	if (!ipv4_is_multicast(loc_addr))
2638 		goto out;
2639 
2640 	rcu_read_lock();
2641 	for_each_pmc_rcu(inet, pmc) {
2642 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2643 		    (pmc->multi.imr_ifindex == dif ||
2644 		     (sdif && pmc->multi.imr_ifindex == sdif)))
2645 			break;
2646 	}
2647 	ret = inet->mc_all;
2648 	if (!pmc)
2649 		goto unlock;
2650 	psl = rcu_dereference(pmc->sflist);
2651 	ret = (pmc->sfmode == MCAST_EXCLUDE);
2652 	if (!psl)
2653 		goto unlock;
2654 
2655 	for (i = 0; i < psl->sl_count; i++) {
2656 		if (psl->sl_addr[i] == rmt_addr)
2657 			break;
2658 	}
2659 	ret = 0;
2660 	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2661 		goto unlock;
2662 	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2663 		goto unlock;
2664 	ret = 1;
2665 unlock:
2666 	rcu_read_unlock();
2667 out:
2668 	return ret;
2669 }
2670 
2671 /*
2672  *	A socket is closing.
2673  */
2674 
2675 void ip_mc_drop_socket(struct sock *sk)
2676 {
2677 	struct inet_sock *inet = inet_sk(sk);
2678 	struct ip_mc_socklist *iml;
2679 	struct net *net = sock_net(sk);
2680 
2681 	if (!inet->mc_list)
2682 		return;
2683 
2684 	rtnl_lock();
2685 	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2686 		struct in_device *in_dev;
2687 
2688 		inet->mc_list = iml->next_rcu;
2689 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2690 		(void) ip_mc_leave_src(sk, iml, in_dev);
2691 		if (in_dev)
2692 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2693 		/* decrease mem now to avoid the memleak warning */
2694 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2695 		kfree_rcu(iml, rcu);
2696 	}
2697 	rtnl_unlock();
2698 }
2699 
2700 /* called with rcu_read_lock() */
2701 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
2702 {
2703 	struct ip_mc_list *im;
2704 	struct ip_mc_list __rcu **mc_hash;
2705 	struct ip_sf_list *psf;
2706 	int rv = 0;
2707 
2708 	mc_hash = rcu_dereference(in_dev->mc_hash);
2709 	if (mc_hash) {
2710 		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2711 
2712 		for (im = rcu_dereference(mc_hash[hash]);
2713 		     im != NULL;
2714 		     im = rcu_dereference(im->next_hash)) {
2715 			if (im->multiaddr == mc_addr)
2716 				break;
2717 		}
2718 	} else {
2719 		for_each_pmc_rcu(in_dev, im) {
2720 			if (im->multiaddr == mc_addr)
2721 				break;
2722 		}
2723 	}
2724 	if (im && proto == IPPROTO_IGMP) {
2725 		rv = 1;
2726 	} else if (im) {
2727 		if (src_addr) {
2728 			for (psf = im->sources; psf; psf = psf->sf_next) {
2729 				if (psf->sf_inaddr == src_addr)
2730 					break;
2731 			}
2732 			if (psf)
2733 				rv = psf->sf_count[MCAST_INCLUDE] ||
2734 					psf->sf_count[MCAST_EXCLUDE] !=
2735 					im->sfcount[MCAST_EXCLUDE];
2736 			else
2737 				rv = im->sfcount[MCAST_EXCLUDE] != 0;
2738 		} else
2739 			rv = 1; /* unspecified source; tentatively allow */
2740 	}
2741 	return rv;
2742 }
2743 
2744 #if defined(CONFIG_PROC_FS)
2745 struct igmp_mc_iter_state {
2746 	struct seq_net_private p;
2747 	struct net_device *dev;
2748 	struct in_device *in_dev;
2749 };
2750 
2751 #define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
2752 
2753 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2754 {
2755 	struct net *net = seq_file_net(seq);
2756 	struct ip_mc_list *im = NULL;
2757 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2758 
2759 	state->in_dev = NULL;
2760 	for_each_netdev_rcu(net, state->dev) {
2761 		struct in_device *in_dev;
2762 
2763 		in_dev = __in_dev_get_rcu(state->dev);
2764 		if (!in_dev)
2765 			continue;
2766 		im = rcu_dereference(in_dev->mc_list);
2767 		if (im) {
2768 			state->in_dev = in_dev;
2769 			break;
2770 		}
2771 	}
2772 	return im;
2773 }
2774 
2775 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2776 {
2777 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2778 
2779 	im = rcu_dereference(im->next_rcu);
2780 	while (!im) {
2781 		state->dev = next_net_device_rcu(state->dev);
2782 		if (!state->dev) {
2783 			state->in_dev = NULL;
2784 			break;
2785 		}
2786 		state->in_dev = __in_dev_get_rcu(state->dev);
2787 		if (!state->in_dev)
2788 			continue;
2789 		im = rcu_dereference(state->in_dev->mc_list);
2790 	}
2791 	return im;
2792 }
2793 
2794 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2795 {
2796 	struct ip_mc_list *im = igmp_mc_get_first(seq);
2797 	if (im)
2798 		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2799 			--pos;
2800 	return pos ? NULL : im;
2801 }
2802 
2803 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2804 	__acquires(rcu)
2805 {
2806 	rcu_read_lock();
2807 	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2808 }
2809 
2810 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2811 {
2812 	struct ip_mc_list *im;
2813 	if (v == SEQ_START_TOKEN)
2814 		im = igmp_mc_get_first(seq);
2815 	else
2816 		im = igmp_mc_get_next(seq, v);
2817 	++*pos;
2818 	return im;
2819 }
2820 
2821 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2822 	__releases(rcu)
2823 {
2824 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2825 
2826 	state->in_dev = NULL;
2827 	state->dev = NULL;
2828 	rcu_read_unlock();
2829 }
2830 
2831 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2832 {
2833 	if (v == SEQ_START_TOKEN)
2834 		seq_puts(seq,
2835 			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2836 	else {
2837 		struct ip_mc_list *im = (struct ip_mc_list *)v;
2838 		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2839 		char   *querier;
2840 		long delta;
2841 
2842 #ifdef CONFIG_IP_MULTICAST
2843 		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2844 			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
2845 			  "V3";
2846 #else
2847 		querier = "NONE";
2848 #endif
2849 
2850 		if (rcu_access_pointer(state->in_dev->mc_list) == im) {
2851 			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2852 				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2853 		}
2854 
2855 		delta = im->timer.expires - jiffies;
2856 		seq_printf(seq,
2857 			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2858 			   im->multiaddr, im->users,
2859 			   im->tm_running,
2860 			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2861 			   im->reporter);
2862 	}
2863 	return 0;
2864 }
2865 
2866 static const struct seq_operations igmp_mc_seq_ops = {
2867 	.start	=	igmp_mc_seq_start,
2868 	.next	=	igmp_mc_seq_next,
2869 	.stop	=	igmp_mc_seq_stop,
2870 	.show	=	igmp_mc_seq_show,
2871 };
2872 
2873 struct igmp_mcf_iter_state {
2874 	struct seq_net_private p;
2875 	struct net_device *dev;
2876 	struct in_device *idev;
2877 	struct ip_mc_list *im;
2878 };
2879 
2880 #define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
2881 
2882 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2883 {
2884 	struct net *net = seq_file_net(seq);
2885 	struct ip_sf_list *psf = NULL;
2886 	struct ip_mc_list *im = NULL;
2887 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2888 
2889 	state->idev = NULL;
2890 	state->im = NULL;
2891 	for_each_netdev_rcu(net, state->dev) {
2892 		struct in_device *idev;
2893 		idev = __in_dev_get_rcu(state->dev);
2894 		if (unlikely(!idev))
2895 			continue;
2896 		im = rcu_dereference(idev->mc_list);
2897 		if (likely(im)) {
2898 			spin_lock_bh(&im->lock);
2899 			psf = im->sources;
2900 			if (likely(psf)) {
2901 				state->im = im;
2902 				state->idev = idev;
2903 				break;
2904 			}
2905 			spin_unlock_bh(&im->lock);
2906 		}
2907 	}
2908 	return psf;
2909 }
2910 
2911 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2912 {
2913 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2914 
2915 	psf = psf->sf_next;
2916 	while (!psf) {
2917 		spin_unlock_bh(&state->im->lock);
2918 		state->im = state->im->next;
2919 		while (!state->im) {
2920 			state->dev = next_net_device_rcu(state->dev);
2921 			if (!state->dev) {
2922 				state->idev = NULL;
2923 				goto out;
2924 			}
2925 			state->idev = __in_dev_get_rcu(state->dev);
2926 			if (!state->idev)
2927 				continue;
2928 			state->im = rcu_dereference(state->idev->mc_list);
2929 		}
2930 		if (!state->im)
2931 			break;
2932 		spin_lock_bh(&state->im->lock);
2933 		psf = state->im->sources;
2934 	}
2935 out:
2936 	return psf;
2937 }
2938 
2939 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2940 {
2941 	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2942 	if (psf)
2943 		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2944 			--pos;
2945 	return pos ? NULL : psf;
2946 }
2947 
2948 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2949 	__acquires(rcu)
2950 {
2951 	rcu_read_lock();
2952 	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2953 }
2954 
2955 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2956 {
2957 	struct ip_sf_list *psf;
2958 	if (v == SEQ_START_TOKEN)
2959 		psf = igmp_mcf_get_first(seq);
2960 	else
2961 		psf = igmp_mcf_get_next(seq, v);
2962 	++*pos;
2963 	return psf;
2964 }
2965 
2966 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2967 	__releases(rcu)
2968 {
2969 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2970 	if (likely(state->im)) {
2971 		spin_unlock_bh(&state->im->lock);
2972 		state->im = NULL;
2973 	}
2974 	state->idev = NULL;
2975 	state->dev = NULL;
2976 	rcu_read_unlock();
2977 }
2978 
2979 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2980 {
2981 	struct ip_sf_list *psf = (struct ip_sf_list *)v;
2982 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2983 
2984 	if (v == SEQ_START_TOKEN) {
2985 		seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
2986 	} else {
2987 		seq_printf(seq,
2988 			   "%3d %6.6s 0x%08x "
2989 			   "0x%08x %6lu %6lu\n",
2990 			   state->dev->ifindex, state->dev->name,
2991 			   ntohl(state->im->multiaddr),
2992 			   ntohl(psf->sf_inaddr),
2993 			   psf->sf_count[MCAST_INCLUDE],
2994 			   psf->sf_count[MCAST_EXCLUDE]);
2995 	}
2996 	return 0;
2997 }
2998 
2999 static const struct seq_operations igmp_mcf_seq_ops = {
3000 	.start	=	igmp_mcf_seq_start,
3001 	.next	=	igmp_mcf_seq_next,
3002 	.stop	=	igmp_mcf_seq_stop,
3003 	.show	=	igmp_mcf_seq_show,
3004 };
3005 
3006 static int __net_init igmp_net_init(struct net *net)
3007 {
3008 	struct proc_dir_entry *pde;
3009 	int err;
3010 
3011 	pde = proc_create_net("igmp", 0444, net->proc_net, &igmp_mc_seq_ops,
3012 			sizeof(struct igmp_mc_iter_state));
3013 	if (!pde)
3014 		goto out_igmp;
3015 	pde = proc_create_net("mcfilter", 0444, net->proc_net,
3016 			&igmp_mcf_seq_ops, sizeof(struct igmp_mcf_iter_state));
3017 	if (!pde)
3018 		goto out_mcfilter;
3019 	err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
3020 				   SOCK_DGRAM, 0, net);
3021 	if (err < 0) {
3022 		pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
3023 		       err);
3024 		goto out_sock;
3025 	}
3026 
3027 	return 0;
3028 
3029 out_sock:
3030 	remove_proc_entry("mcfilter", net->proc_net);
3031 out_mcfilter:
3032 	remove_proc_entry("igmp", net->proc_net);
3033 out_igmp:
3034 	return -ENOMEM;
3035 }
3036 
3037 static void __net_exit igmp_net_exit(struct net *net)
3038 {
3039 	remove_proc_entry("mcfilter", net->proc_net);
3040 	remove_proc_entry("igmp", net->proc_net);
3041 	inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
3042 }
3043 
3044 static struct pernet_operations igmp_net_ops = {
3045 	.init = igmp_net_init,
3046 	.exit = igmp_net_exit,
3047 };
3048 #endif
3049 
3050 static int igmp_netdev_event(struct notifier_block *this,
3051 			     unsigned long event, void *ptr)
3052 {
3053 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3054 	struct in_device *in_dev;
3055 
3056 	switch (event) {
3057 	case NETDEV_RESEND_IGMP:
3058 		in_dev = __in_dev_get_rtnl(dev);
3059 		if (in_dev)
3060 			ip_mc_rejoin_groups(in_dev);
3061 		break;
3062 	default:
3063 		break;
3064 	}
3065 	return NOTIFY_DONE;
3066 }
3067 
3068 static struct notifier_block igmp_notifier = {
3069 	.notifier_call = igmp_netdev_event,
3070 };
3071 
3072 int __init igmp_mc_init(void)
3073 {
3074 #if defined(CONFIG_PROC_FS)
3075 	int err;
3076 
3077 	err = register_pernet_subsys(&igmp_net_ops);
3078 	if (err)
3079 		return err;
3080 	err = register_netdevice_notifier(&igmp_notifier);
3081 	if (err)
3082 		goto reg_notif_fail;
3083 	return 0;
3084 
3085 reg_notif_fail:
3086 	unregister_pernet_subsys(&igmp_net_ops);
3087 	return err;
3088 #else
3089 	return register_netdevice_notifier(&igmp_notifier);
3090 #endif
3091 }
3092