xref: /linux/net/ipv4/igmp.c (revision 662fa3d6099374c4615bf64d06895e3573b935b2)
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_QUERY_INTERVAL			(125*HZ)
111 #define IGMP_QUERY_RESPONSE_INTERVAL		(10*HZ)
112 
113 #define IGMP_INITIAL_REPORT_DELAY		(1)
114 
115 /* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
116  * IGMP specs require to report membership immediately after
117  * joining a group, but we delay the first report by a
118  * small interval. It seems more natural and still does not
119  * contradict to specs provided this delay is small enough.
120  */
121 
122 #define IGMP_V1_SEEN(in_dev) \
123 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
124 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
125 	 ((in_dev)->mr_v1_seen && \
126 	  time_before(jiffies, (in_dev)->mr_v1_seen)))
127 #define IGMP_V2_SEEN(in_dev) \
128 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
129 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
130 	 ((in_dev)->mr_v2_seen && \
131 	  time_before(jiffies, (in_dev)->mr_v2_seen)))
132 
133 static int unsolicited_report_interval(struct in_device *in_dev)
134 {
135 	int interval_ms, interval_jiffies;
136 
137 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
138 		interval_ms = IN_DEV_CONF_GET(
139 			in_dev,
140 			IGMPV2_UNSOLICITED_REPORT_INTERVAL);
141 	else /* v3 */
142 		interval_ms = IN_DEV_CONF_GET(
143 			in_dev,
144 			IGMPV3_UNSOLICITED_REPORT_INTERVAL);
145 
146 	interval_jiffies = msecs_to_jiffies(interval_ms);
147 
148 	/* _timer functions can't handle a delay of 0 jiffies so ensure
149 	 *  we always return a positive value.
150 	 */
151 	if (interval_jiffies <= 0)
152 		interval_jiffies = 1;
153 	return interval_jiffies;
154 }
155 
156 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
157 			      gfp_t gfp);
158 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im);
159 static void igmpv3_clear_delrec(struct in_device *in_dev);
160 static int sf_setstate(struct ip_mc_list *pmc);
161 static void sf_markstate(struct ip_mc_list *pmc);
162 #endif
163 static void ip_mc_clear_src(struct ip_mc_list *pmc);
164 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
165 			 int sfcount, __be32 *psfsrc, int delta);
166 
167 static void ip_ma_put(struct ip_mc_list *im)
168 {
169 	if (refcount_dec_and_test(&im->refcnt)) {
170 		in_dev_put(im->interface);
171 		kfree_rcu(im, rcu);
172 	}
173 }
174 
175 #define for_each_pmc_rcu(in_dev, pmc)				\
176 	for (pmc = rcu_dereference(in_dev->mc_list);		\
177 	     pmc != NULL;					\
178 	     pmc = rcu_dereference(pmc->next_rcu))
179 
180 #define for_each_pmc_rtnl(in_dev, pmc)				\
181 	for (pmc = rtnl_dereference(in_dev->mc_list);		\
182 	     pmc != NULL;					\
183 	     pmc = rtnl_dereference(pmc->next_rcu))
184 
185 static void ip_sf_list_clear_all(struct ip_sf_list *psf)
186 {
187 	struct ip_sf_list *next;
188 
189 	while (psf) {
190 		next = psf->sf_next;
191 		kfree(psf);
192 		psf = next;
193 	}
194 }
195 
196 #ifdef CONFIG_IP_MULTICAST
197 
198 /*
199  *	Timer management
200  */
201 
202 static void igmp_stop_timer(struct ip_mc_list *im)
203 {
204 	spin_lock_bh(&im->lock);
205 	if (del_timer(&im->timer))
206 		refcount_dec(&im->refcnt);
207 	im->tm_running = 0;
208 	im->reporter = 0;
209 	im->unsolicit_count = 0;
210 	spin_unlock_bh(&im->lock);
211 }
212 
213 /* It must be called with locked im->lock */
214 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
215 {
216 	int tv = prandom_u32() % max_delay;
217 
218 	im->tm_running = 1;
219 	if (!mod_timer(&im->timer, jiffies+tv+2))
220 		refcount_inc(&im->refcnt);
221 }
222 
223 static void igmp_gq_start_timer(struct in_device *in_dev)
224 {
225 	int tv = prandom_u32() % in_dev->mr_maxdelay;
226 	unsigned long exp = jiffies + tv + 2;
227 
228 	if (in_dev->mr_gq_running &&
229 	    time_after_eq(exp, (in_dev->mr_gq_timer).expires))
230 		return;
231 
232 	in_dev->mr_gq_running = 1;
233 	if (!mod_timer(&in_dev->mr_gq_timer, exp))
234 		in_dev_hold(in_dev);
235 }
236 
237 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
238 {
239 	int tv = prandom_u32() % delay;
240 
241 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
242 		in_dev_hold(in_dev);
243 }
244 
245 static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
246 {
247 	spin_lock_bh(&im->lock);
248 	im->unsolicit_count = 0;
249 	if (del_timer(&im->timer)) {
250 		if ((long)(im->timer.expires-jiffies) < max_delay) {
251 			add_timer(&im->timer);
252 			im->tm_running = 1;
253 			spin_unlock_bh(&im->lock);
254 			return;
255 		}
256 		refcount_dec(&im->refcnt);
257 	}
258 	igmp_start_timer(im, max_delay);
259 	spin_unlock_bh(&im->lock);
260 }
261 
262 
263 /*
264  *	Send an IGMP report.
265  */
266 
267 #define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
268 
269 
270 static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
271 	int gdeleted, int sdeleted)
272 {
273 	switch (type) {
274 	case IGMPV3_MODE_IS_INCLUDE:
275 	case IGMPV3_MODE_IS_EXCLUDE:
276 		if (gdeleted || sdeleted)
277 			return 0;
278 		if (!(pmc->gsquery && !psf->sf_gsresp)) {
279 			if (pmc->sfmode == MCAST_INCLUDE)
280 				return 1;
281 			/* don't include if this source is excluded
282 			 * in all filters
283 			 */
284 			if (psf->sf_count[MCAST_INCLUDE])
285 				return type == IGMPV3_MODE_IS_INCLUDE;
286 			return pmc->sfcount[MCAST_EXCLUDE] ==
287 				psf->sf_count[MCAST_EXCLUDE];
288 		}
289 		return 0;
290 	case IGMPV3_CHANGE_TO_INCLUDE:
291 		if (gdeleted || sdeleted)
292 			return 0;
293 		return psf->sf_count[MCAST_INCLUDE] != 0;
294 	case IGMPV3_CHANGE_TO_EXCLUDE:
295 		if (gdeleted || sdeleted)
296 			return 0;
297 		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
298 		    psf->sf_count[MCAST_INCLUDE])
299 			return 0;
300 		return pmc->sfcount[MCAST_EXCLUDE] ==
301 			psf->sf_count[MCAST_EXCLUDE];
302 	case IGMPV3_ALLOW_NEW_SOURCES:
303 		if (gdeleted || !psf->sf_crcount)
304 			return 0;
305 		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
306 	case IGMPV3_BLOCK_OLD_SOURCES:
307 		if (pmc->sfmode == MCAST_INCLUDE)
308 			return gdeleted || (psf->sf_crcount && sdeleted);
309 		return psf->sf_crcount && !gdeleted && !sdeleted;
310 	}
311 	return 0;
312 }
313 
314 static int
315 igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
316 {
317 	struct ip_sf_list *psf;
318 	int scount = 0;
319 
320 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
321 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
322 			continue;
323 		scount++;
324 	}
325 	return scount;
326 }
327 
328 /* source address selection per RFC 3376 section 4.2.13 */
329 static __be32 igmpv3_get_srcaddr(struct net_device *dev,
330 				 const struct flowi4 *fl4)
331 {
332 	struct in_device *in_dev = __in_dev_get_rcu(dev);
333 	const struct in_ifaddr *ifa;
334 
335 	if (!in_dev)
336 		return htonl(INADDR_ANY);
337 
338 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
339 		if (fl4->saddr == ifa->ifa_local)
340 			return fl4->saddr;
341 	}
342 
343 	return htonl(INADDR_ANY);
344 }
345 
346 static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
347 {
348 	struct sk_buff *skb;
349 	struct rtable *rt;
350 	struct iphdr *pip;
351 	struct igmpv3_report *pig;
352 	struct net *net = dev_net(dev);
353 	struct flowi4 fl4;
354 	int hlen = LL_RESERVED_SPACE(dev);
355 	int tlen = dev->needed_tailroom;
356 	unsigned int size = mtu;
357 
358 	while (1) {
359 		skb = alloc_skb(size + hlen + tlen,
360 				GFP_ATOMIC | __GFP_NOWARN);
361 		if (skb)
362 			break;
363 		size >>= 1;
364 		if (size < 256)
365 			return NULL;
366 	}
367 	skb->priority = TC_PRIO_CONTROL;
368 
369 	rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
370 				   0, 0,
371 				   IPPROTO_IGMP, 0, dev->ifindex);
372 	if (IS_ERR(rt)) {
373 		kfree_skb(skb);
374 		return NULL;
375 	}
376 
377 	skb_dst_set(skb, &rt->dst);
378 	skb->dev = dev;
379 
380 	skb_reserve(skb, hlen);
381 	skb_tailroom_reserve(skb, mtu, tlen);
382 
383 	skb_reset_network_header(skb);
384 	pip = ip_hdr(skb);
385 	skb_put(skb, sizeof(struct iphdr) + 4);
386 
387 	pip->version  = 4;
388 	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
389 	pip->tos      = 0xc0;
390 	pip->frag_off = htons(IP_DF);
391 	pip->ttl      = 1;
392 	pip->daddr    = fl4.daddr;
393 
394 	rcu_read_lock();
395 	pip->saddr    = igmpv3_get_srcaddr(dev, &fl4);
396 	rcu_read_unlock();
397 
398 	pip->protocol = IPPROTO_IGMP;
399 	pip->tot_len  = 0;	/* filled in later */
400 	ip_select_ident(net, skb, NULL);
401 	((u8 *)&pip[1])[0] = IPOPT_RA;
402 	((u8 *)&pip[1])[1] = 4;
403 	((u8 *)&pip[1])[2] = 0;
404 	((u8 *)&pip[1])[3] = 0;
405 
406 	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
407 	skb_put(skb, sizeof(*pig));
408 	pig = igmpv3_report_hdr(skb);
409 	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
410 	pig->resv1 = 0;
411 	pig->csum = 0;
412 	pig->resv2 = 0;
413 	pig->ngrec = 0;
414 	return skb;
415 }
416 
417 static int igmpv3_sendpack(struct sk_buff *skb)
418 {
419 	struct igmphdr *pig = igmp_hdr(skb);
420 	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
421 
422 	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
423 
424 	return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
425 }
426 
427 static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
428 {
429 	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
430 }
431 
432 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
433 	int type, struct igmpv3_grec **ppgr, unsigned int mtu)
434 {
435 	struct net_device *dev = pmc->interface->dev;
436 	struct igmpv3_report *pih;
437 	struct igmpv3_grec *pgr;
438 
439 	if (!skb) {
440 		skb = igmpv3_newpack(dev, mtu);
441 		if (!skb)
442 			return NULL;
443 	}
444 	pgr = skb_put(skb, sizeof(struct igmpv3_grec));
445 	pgr->grec_type = type;
446 	pgr->grec_auxwords = 0;
447 	pgr->grec_nsrcs = 0;
448 	pgr->grec_mca = pmc->multiaddr;
449 	pih = igmpv3_report_hdr(skb);
450 	pih->ngrec = htons(ntohs(pih->ngrec)+1);
451 	*ppgr = pgr;
452 	return skb;
453 }
454 
455 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
456 
457 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
458 	int type, int gdeleted, int sdeleted)
459 {
460 	struct net_device *dev = pmc->interface->dev;
461 	struct net *net = dev_net(dev);
462 	struct igmpv3_report *pih;
463 	struct igmpv3_grec *pgr = NULL;
464 	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
465 	int scount, stotal, first, isquery, truncate;
466 	unsigned int mtu;
467 
468 	if (pmc->multiaddr == IGMP_ALL_HOSTS)
469 		return skb;
470 	if (ipv4_is_local_multicast(pmc->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
471 		return skb;
472 
473 	mtu = READ_ONCE(dev->mtu);
474 	if (mtu < IPV4_MIN_MTU)
475 		return skb;
476 
477 	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
478 		  type == IGMPV3_MODE_IS_EXCLUDE;
479 	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
480 		    type == IGMPV3_CHANGE_TO_EXCLUDE;
481 
482 	stotal = scount = 0;
483 
484 	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
485 
486 	if (!*psf_list)
487 		goto empty_source;
488 
489 	pih = skb ? igmpv3_report_hdr(skb) : NULL;
490 
491 	/* EX and TO_EX get a fresh packet, if needed */
492 	if (truncate) {
493 		if (pih && pih->ngrec &&
494 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
495 			if (skb)
496 				igmpv3_sendpack(skb);
497 			skb = igmpv3_newpack(dev, mtu);
498 		}
499 	}
500 	first = 1;
501 	psf_prev = NULL;
502 	for (psf = *psf_list; psf; psf = psf_next) {
503 		__be32 *psrc;
504 
505 		psf_next = psf->sf_next;
506 
507 		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
508 			psf_prev = psf;
509 			continue;
510 		}
511 
512 		/* Based on RFC3376 5.1. Should not send source-list change
513 		 * records when there is a filter mode change.
514 		 */
515 		if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) ||
516 		     (!gdeleted && pmc->crcount)) &&
517 		    (type == IGMPV3_ALLOW_NEW_SOURCES ||
518 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount)
519 			goto decrease_sf_crcount;
520 
521 		/* clear marks on query responses */
522 		if (isquery)
523 			psf->sf_gsresp = 0;
524 
525 		if (AVAILABLE(skb) < sizeof(__be32) +
526 		    first*sizeof(struct igmpv3_grec)) {
527 			if (truncate && !first)
528 				break;	 /* truncate these */
529 			if (pgr)
530 				pgr->grec_nsrcs = htons(scount);
531 			if (skb)
532 				igmpv3_sendpack(skb);
533 			skb = igmpv3_newpack(dev, mtu);
534 			first = 1;
535 			scount = 0;
536 		}
537 		if (first) {
538 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
539 			first = 0;
540 		}
541 		if (!skb)
542 			return NULL;
543 		psrc = skb_put(skb, sizeof(__be32));
544 		*psrc = psf->sf_inaddr;
545 		scount++; stotal++;
546 		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
547 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
548 decrease_sf_crcount:
549 			psf->sf_crcount--;
550 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
551 				if (psf_prev)
552 					psf_prev->sf_next = psf->sf_next;
553 				else
554 					*psf_list = psf->sf_next;
555 				kfree(psf);
556 				continue;
557 			}
558 		}
559 		psf_prev = psf;
560 	}
561 
562 empty_source:
563 	if (!stotal) {
564 		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
565 		    type == IGMPV3_BLOCK_OLD_SOURCES)
566 			return skb;
567 		if (pmc->crcount || isquery) {
568 			/* make sure we have room for group header */
569 			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
570 				igmpv3_sendpack(skb);
571 				skb = NULL; /* add_grhead will get a new one */
572 			}
573 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
574 		}
575 	}
576 	if (pgr)
577 		pgr->grec_nsrcs = htons(scount);
578 
579 	if (isquery)
580 		pmc->gsquery = 0;	/* clear query state on report */
581 	return skb;
582 }
583 
584 static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
585 {
586 	struct sk_buff *skb = NULL;
587 	struct net *net = dev_net(in_dev->dev);
588 	int type;
589 
590 	if (!pmc) {
591 		rcu_read_lock();
592 		for_each_pmc_rcu(in_dev, pmc) {
593 			if (pmc->multiaddr == IGMP_ALL_HOSTS)
594 				continue;
595 			if (ipv4_is_local_multicast(pmc->multiaddr) &&
596 			     !net->ipv4.sysctl_igmp_llm_reports)
597 				continue;
598 			spin_lock_bh(&pmc->lock);
599 			if (pmc->sfcount[MCAST_EXCLUDE])
600 				type = IGMPV3_MODE_IS_EXCLUDE;
601 			else
602 				type = IGMPV3_MODE_IS_INCLUDE;
603 			skb = add_grec(skb, pmc, type, 0, 0);
604 			spin_unlock_bh(&pmc->lock);
605 		}
606 		rcu_read_unlock();
607 	} else {
608 		spin_lock_bh(&pmc->lock);
609 		if (pmc->sfcount[MCAST_EXCLUDE])
610 			type = IGMPV3_MODE_IS_EXCLUDE;
611 		else
612 			type = IGMPV3_MODE_IS_INCLUDE;
613 		skb = add_grec(skb, pmc, type, 0, 0);
614 		spin_unlock_bh(&pmc->lock);
615 	}
616 	if (!skb)
617 		return 0;
618 	return igmpv3_sendpack(skb);
619 }
620 
621 /*
622  * remove zero-count source records from a source filter list
623  */
624 static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
625 {
626 	struct ip_sf_list *psf_prev, *psf_next, *psf;
627 
628 	psf_prev = NULL;
629 	for (psf = *ppsf; psf; psf = psf_next) {
630 		psf_next = psf->sf_next;
631 		if (psf->sf_crcount == 0) {
632 			if (psf_prev)
633 				psf_prev->sf_next = psf->sf_next;
634 			else
635 				*ppsf = psf->sf_next;
636 			kfree(psf);
637 		} else
638 			psf_prev = psf;
639 	}
640 }
641 
642 static void kfree_pmc(struct ip_mc_list *pmc)
643 {
644 	ip_sf_list_clear_all(pmc->sources);
645 	ip_sf_list_clear_all(pmc->tomb);
646 	kfree(pmc);
647 }
648 
649 static void igmpv3_send_cr(struct in_device *in_dev)
650 {
651 	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
652 	struct sk_buff *skb = NULL;
653 	int type, dtype;
654 
655 	rcu_read_lock();
656 	spin_lock_bh(&in_dev->mc_tomb_lock);
657 
658 	/* deleted MCA's */
659 	pmc_prev = NULL;
660 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
661 		pmc_next = pmc->next;
662 		if (pmc->sfmode == MCAST_INCLUDE) {
663 			type = IGMPV3_BLOCK_OLD_SOURCES;
664 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
665 			skb = add_grec(skb, pmc, type, 1, 0);
666 			skb = add_grec(skb, pmc, dtype, 1, 1);
667 		}
668 		if (pmc->crcount) {
669 			if (pmc->sfmode == MCAST_EXCLUDE) {
670 				type = IGMPV3_CHANGE_TO_INCLUDE;
671 				skb = add_grec(skb, pmc, type, 1, 0);
672 			}
673 			pmc->crcount--;
674 			if (pmc->crcount == 0) {
675 				igmpv3_clear_zeros(&pmc->tomb);
676 				igmpv3_clear_zeros(&pmc->sources);
677 			}
678 		}
679 		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
680 			if (pmc_prev)
681 				pmc_prev->next = pmc_next;
682 			else
683 				in_dev->mc_tomb = pmc_next;
684 			in_dev_put(pmc->interface);
685 			kfree_pmc(pmc);
686 		} else
687 			pmc_prev = pmc;
688 	}
689 	spin_unlock_bh(&in_dev->mc_tomb_lock);
690 
691 	/* change recs */
692 	for_each_pmc_rcu(in_dev, pmc) {
693 		spin_lock_bh(&pmc->lock);
694 		if (pmc->sfcount[MCAST_EXCLUDE]) {
695 			type = IGMPV3_BLOCK_OLD_SOURCES;
696 			dtype = IGMPV3_ALLOW_NEW_SOURCES;
697 		} else {
698 			type = IGMPV3_ALLOW_NEW_SOURCES;
699 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
700 		}
701 		skb = add_grec(skb, pmc, type, 0, 0);
702 		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
703 
704 		/* filter mode changes */
705 		if (pmc->crcount) {
706 			if (pmc->sfmode == MCAST_EXCLUDE)
707 				type = IGMPV3_CHANGE_TO_EXCLUDE;
708 			else
709 				type = IGMPV3_CHANGE_TO_INCLUDE;
710 			skb = add_grec(skb, pmc, type, 0, 0);
711 			pmc->crcount--;
712 		}
713 		spin_unlock_bh(&pmc->lock);
714 	}
715 	rcu_read_unlock();
716 
717 	if (!skb)
718 		return;
719 	(void) igmpv3_sendpack(skb);
720 }
721 
722 static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
723 	int type)
724 {
725 	struct sk_buff *skb;
726 	struct iphdr *iph;
727 	struct igmphdr *ih;
728 	struct rtable *rt;
729 	struct net_device *dev = in_dev->dev;
730 	struct net *net = dev_net(dev);
731 	__be32	group = pmc ? pmc->multiaddr : 0;
732 	struct flowi4 fl4;
733 	__be32	dst;
734 	int hlen, tlen;
735 
736 	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
737 		return igmpv3_send_report(in_dev, pmc);
738 
739 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
740 		return 0;
741 
742 	if (type == IGMP_HOST_LEAVE_MESSAGE)
743 		dst = IGMP_ALL_ROUTER;
744 	else
745 		dst = group;
746 
747 	rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
748 				   0, 0,
749 				   IPPROTO_IGMP, 0, dev->ifindex);
750 	if (IS_ERR(rt))
751 		return -1;
752 
753 	hlen = LL_RESERVED_SPACE(dev);
754 	tlen = dev->needed_tailroom;
755 	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
756 	if (!skb) {
757 		ip_rt_put(rt);
758 		return -1;
759 	}
760 	skb->priority = TC_PRIO_CONTROL;
761 
762 	skb_dst_set(skb, &rt->dst);
763 
764 	skb_reserve(skb, hlen);
765 
766 	skb_reset_network_header(skb);
767 	iph = ip_hdr(skb);
768 	skb_put(skb, sizeof(struct iphdr) + 4);
769 
770 	iph->version  = 4;
771 	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
772 	iph->tos      = 0xc0;
773 	iph->frag_off = htons(IP_DF);
774 	iph->ttl      = 1;
775 	iph->daddr    = dst;
776 	iph->saddr    = fl4.saddr;
777 	iph->protocol = IPPROTO_IGMP;
778 	ip_select_ident(net, skb, NULL);
779 	((u8 *)&iph[1])[0] = IPOPT_RA;
780 	((u8 *)&iph[1])[1] = 4;
781 	((u8 *)&iph[1])[2] = 0;
782 	((u8 *)&iph[1])[3] = 0;
783 
784 	ih = skb_put(skb, sizeof(struct igmphdr));
785 	ih->type = type;
786 	ih->code = 0;
787 	ih->csum = 0;
788 	ih->group = group;
789 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
790 
791 	return ip_local_out(net, skb->sk, skb);
792 }
793 
794 static void igmp_gq_timer_expire(struct timer_list *t)
795 {
796 	struct in_device *in_dev = from_timer(in_dev, t, mr_gq_timer);
797 
798 	in_dev->mr_gq_running = 0;
799 	igmpv3_send_report(in_dev, NULL);
800 	in_dev_put(in_dev);
801 }
802 
803 static void igmp_ifc_timer_expire(struct timer_list *t)
804 {
805 	struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer);
806 
807 	igmpv3_send_cr(in_dev);
808 	if (in_dev->mr_ifc_count) {
809 		in_dev->mr_ifc_count--;
810 		igmp_ifc_start_timer(in_dev,
811 				     unsolicited_report_interval(in_dev));
812 	}
813 	in_dev_put(in_dev);
814 }
815 
816 static void igmp_ifc_event(struct in_device *in_dev)
817 {
818 	struct net *net = dev_net(in_dev->dev);
819 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
820 		return;
821 	in_dev->mr_ifc_count = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
822 	igmp_ifc_start_timer(in_dev, 1);
823 }
824 
825 
826 static void igmp_timer_expire(struct timer_list *t)
827 {
828 	struct ip_mc_list *im = from_timer(im, t, timer);
829 	struct in_device *in_dev = im->interface;
830 
831 	spin_lock(&im->lock);
832 	im->tm_running = 0;
833 
834 	if (im->unsolicit_count && --im->unsolicit_count)
835 		igmp_start_timer(im, unsolicited_report_interval(in_dev));
836 
837 	im->reporter = 1;
838 	spin_unlock(&im->lock);
839 
840 	if (IGMP_V1_SEEN(in_dev))
841 		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
842 	else if (IGMP_V2_SEEN(in_dev))
843 		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
844 	else
845 		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
846 
847 	ip_ma_put(im);
848 }
849 
850 /* mark EXCLUDE-mode sources */
851 static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
852 {
853 	struct ip_sf_list *psf;
854 	int i, scount;
855 
856 	scount = 0;
857 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
858 		if (scount == nsrcs)
859 			break;
860 		for (i = 0; i < nsrcs; i++) {
861 			/* skip inactive filters */
862 			if (psf->sf_count[MCAST_INCLUDE] ||
863 			    pmc->sfcount[MCAST_EXCLUDE] !=
864 			    psf->sf_count[MCAST_EXCLUDE])
865 				break;
866 			if (srcs[i] == psf->sf_inaddr) {
867 				scount++;
868 				break;
869 			}
870 		}
871 	}
872 	pmc->gsquery = 0;
873 	if (scount == nsrcs)	/* all sources excluded */
874 		return 0;
875 	return 1;
876 }
877 
878 static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
879 {
880 	struct ip_sf_list *psf;
881 	int i, scount;
882 
883 	if (pmc->sfmode == MCAST_EXCLUDE)
884 		return igmp_xmarksources(pmc, nsrcs, srcs);
885 
886 	/* mark INCLUDE-mode sources */
887 	scount = 0;
888 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
889 		if (scount == nsrcs)
890 			break;
891 		for (i = 0; i < nsrcs; i++)
892 			if (srcs[i] == psf->sf_inaddr) {
893 				psf->sf_gsresp = 1;
894 				scount++;
895 				break;
896 			}
897 	}
898 	if (!scount) {
899 		pmc->gsquery = 0;
900 		return 0;
901 	}
902 	pmc->gsquery = 1;
903 	return 1;
904 }
905 
906 /* return true if packet was dropped */
907 static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
908 {
909 	struct ip_mc_list *im;
910 	struct net *net = dev_net(in_dev->dev);
911 
912 	/* Timers are only set for non-local groups */
913 
914 	if (group == IGMP_ALL_HOSTS)
915 		return false;
916 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
917 		return false;
918 
919 	rcu_read_lock();
920 	for_each_pmc_rcu(in_dev, im) {
921 		if (im->multiaddr == group) {
922 			igmp_stop_timer(im);
923 			break;
924 		}
925 	}
926 	rcu_read_unlock();
927 	return false;
928 }
929 
930 /* return true if packet was dropped */
931 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
932 	int len)
933 {
934 	struct igmphdr 		*ih = igmp_hdr(skb);
935 	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
936 	struct ip_mc_list	*im;
937 	__be32			group = ih->group;
938 	int			max_delay;
939 	int			mark = 0;
940 	struct net		*net = dev_net(in_dev->dev);
941 
942 
943 	if (len == 8) {
944 		if (ih->code == 0) {
945 			/* Alas, old v1 router presents here. */
946 
947 			max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
948 			in_dev->mr_v1_seen = jiffies +
949 				(in_dev->mr_qrv * in_dev->mr_qi) +
950 				in_dev->mr_qri;
951 			group = 0;
952 		} else {
953 			/* v2 router present */
954 			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
955 			in_dev->mr_v2_seen = jiffies +
956 				(in_dev->mr_qrv * in_dev->mr_qi) +
957 				in_dev->mr_qri;
958 		}
959 		/* cancel the interface change timer */
960 		in_dev->mr_ifc_count = 0;
961 		if (del_timer(&in_dev->mr_ifc_timer))
962 			__in_dev_put(in_dev);
963 		/* clear deleted report items */
964 		igmpv3_clear_delrec(in_dev);
965 	} else if (len < 12) {
966 		return true;	/* ignore bogus packet; freed by caller */
967 	} else if (IGMP_V1_SEEN(in_dev)) {
968 		/* This is a v3 query with v1 queriers present */
969 		max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
970 		group = 0;
971 	} else if (IGMP_V2_SEEN(in_dev)) {
972 		/* this is a v3 query with v2 queriers present;
973 		 * Interpretation of the max_delay code is problematic here.
974 		 * A real v2 host would use ih_code directly, while v3 has a
975 		 * different encoding. We use the v3 encoding as more likely
976 		 * to be intended in a v3 query.
977 		 */
978 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
979 		if (!max_delay)
980 			max_delay = 1;	/* can't mod w/ 0 */
981 	} else { /* v3 */
982 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
983 			return true;
984 
985 		ih3 = igmpv3_query_hdr(skb);
986 		if (ih3->nsrcs) {
987 			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
988 					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
989 				return true;
990 			ih3 = igmpv3_query_hdr(skb);
991 		}
992 
993 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
994 		if (!max_delay)
995 			max_delay = 1;	/* can't mod w/ 0 */
996 		in_dev->mr_maxdelay = max_delay;
997 
998 		/* RFC3376, 4.1.6. QRV and 4.1.7. QQIC, when the most recently
999 		 * received value was zero, use the default or statically
1000 		 * configured value.
1001 		 */
1002 		in_dev->mr_qrv = ih3->qrv ?: net->ipv4.sysctl_igmp_qrv;
1003 		in_dev->mr_qi = IGMPV3_QQIC(ih3->qqic)*HZ ?: IGMP_QUERY_INTERVAL;
1004 
1005 		/* RFC3376, 8.3. Query Response Interval:
1006 		 * The number of seconds represented by the [Query Response
1007 		 * Interval] must be less than the [Query Interval].
1008 		 */
1009 		if (in_dev->mr_qri >= in_dev->mr_qi)
1010 			in_dev->mr_qri = (in_dev->mr_qi/HZ - 1)*HZ;
1011 
1012 		if (!group) { /* general query */
1013 			if (ih3->nsrcs)
1014 				return true;	/* no sources allowed */
1015 			igmp_gq_start_timer(in_dev);
1016 			return false;
1017 		}
1018 		/* mark sources to include, if group & source-specific */
1019 		mark = ih3->nsrcs != 0;
1020 	}
1021 
1022 	/*
1023 	 * - Start the timers in all of our membership records
1024 	 *   that the query applies to for the interface on
1025 	 *   which the query arrived excl. those that belong
1026 	 *   to a "local" group (224.0.0.X)
1027 	 * - For timers already running check if they need to
1028 	 *   be reset.
1029 	 * - Use the igmp->igmp_code field as the maximum
1030 	 *   delay possible
1031 	 */
1032 	rcu_read_lock();
1033 	for_each_pmc_rcu(in_dev, im) {
1034 		int changed;
1035 
1036 		if (group && group != im->multiaddr)
1037 			continue;
1038 		if (im->multiaddr == IGMP_ALL_HOSTS)
1039 			continue;
1040 		if (ipv4_is_local_multicast(im->multiaddr) &&
1041 		    !net->ipv4.sysctl_igmp_llm_reports)
1042 			continue;
1043 		spin_lock_bh(&im->lock);
1044 		if (im->tm_running)
1045 			im->gsquery = im->gsquery && mark;
1046 		else
1047 			im->gsquery = mark;
1048 		changed = !im->gsquery ||
1049 			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
1050 		spin_unlock_bh(&im->lock);
1051 		if (changed)
1052 			igmp_mod_timer(im, max_delay);
1053 	}
1054 	rcu_read_unlock();
1055 	return false;
1056 }
1057 
1058 /* called in rcu_read_lock() section */
1059 int igmp_rcv(struct sk_buff *skb)
1060 {
1061 	/* This basically follows the spec line by line -- see RFC1112 */
1062 	struct igmphdr *ih;
1063 	struct net_device *dev = skb->dev;
1064 	struct in_device *in_dev;
1065 	int len = skb->len;
1066 	bool dropped = true;
1067 
1068 	if (netif_is_l3_master(dev)) {
1069 		dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
1070 		if (!dev)
1071 			goto drop;
1072 	}
1073 
1074 	in_dev = __in_dev_get_rcu(dev);
1075 	if (!in_dev)
1076 		goto drop;
1077 
1078 	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
1079 		goto drop;
1080 
1081 	if (skb_checksum_simple_validate(skb))
1082 		goto drop;
1083 
1084 	ih = igmp_hdr(skb);
1085 	switch (ih->type) {
1086 	case IGMP_HOST_MEMBERSHIP_QUERY:
1087 		dropped = igmp_heard_query(in_dev, skb, len);
1088 		break;
1089 	case IGMP_HOST_MEMBERSHIP_REPORT:
1090 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1091 		/* Is it our report looped back? */
1092 		if (rt_is_output_route(skb_rtable(skb)))
1093 			break;
1094 		/* don't rely on MC router hearing unicast reports */
1095 		if (skb->pkt_type == PACKET_MULTICAST ||
1096 		    skb->pkt_type == PACKET_BROADCAST)
1097 			dropped = igmp_heard_report(in_dev, ih->group);
1098 		break;
1099 	case IGMP_PIM:
1100 #ifdef CONFIG_IP_PIMSM_V1
1101 		return pim_rcv_v1(skb);
1102 #endif
1103 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1104 	case IGMP_DVMRP:
1105 	case IGMP_TRACE:
1106 	case IGMP_HOST_LEAVE_MESSAGE:
1107 	case IGMP_MTRACE:
1108 	case IGMP_MTRACE_RESP:
1109 		break;
1110 	default:
1111 		break;
1112 	}
1113 
1114 drop:
1115 	if (dropped)
1116 		kfree_skb(skb);
1117 	else
1118 		consume_skb(skb);
1119 	return 0;
1120 }
1121 
1122 #endif
1123 
1124 
1125 /*
1126  *	Add a filter to a device
1127  */
1128 
1129 static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
1130 {
1131 	char buf[MAX_ADDR_LEN];
1132 	struct net_device *dev = in_dev->dev;
1133 
1134 	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
1135 	   We will get multicast token leakage, when IFF_MULTICAST
1136 	   is changed. This check should be done in ndo_set_rx_mode
1137 	   routine. Something sort of:
1138 	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
1139 	   --ANK
1140 	   */
1141 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1142 		dev_mc_add(dev, buf);
1143 }
1144 
1145 /*
1146  *	Remove a filter from a device
1147  */
1148 
1149 static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
1150 {
1151 	char buf[MAX_ADDR_LEN];
1152 	struct net_device *dev = in_dev->dev;
1153 
1154 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1155 		dev_mc_del(dev, buf);
1156 }
1157 
1158 #ifdef CONFIG_IP_MULTICAST
1159 /*
1160  * deleted ip_mc_list manipulation
1161  */
1162 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
1163 			      gfp_t gfp)
1164 {
1165 	struct ip_mc_list *pmc;
1166 	struct net *net = dev_net(in_dev->dev);
1167 
1168 	/* this is an "ip_mc_list" for convenience; only the fields below
1169 	 * are actually used. In particular, the refcnt and users are not
1170 	 * used for management of the delete list. Using the same structure
1171 	 * for deleted items allows change reports to use common code with
1172 	 * non-deleted or query-response MCA's.
1173 	 */
1174 	pmc = kzalloc(sizeof(*pmc), gfp);
1175 	if (!pmc)
1176 		return;
1177 	spin_lock_init(&pmc->lock);
1178 	spin_lock_bh(&im->lock);
1179 	pmc->interface = im->interface;
1180 	in_dev_hold(in_dev);
1181 	pmc->multiaddr = im->multiaddr;
1182 	pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1183 	pmc->sfmode = im->sfmode;
1184 	if (pmc->sfmode == MCAST_INCLUDE) {
1185 		struct ip_sf_list *psf;
1186 
1187 		pmc->tomb = im->tomb;
1188 		pmc->sources = im->sources;
1189 		im->tomb = im->sources = NULL;
1190 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1191 			psf->sf_crcount = pmc->crcount;
1192 	}
1193 	spin_unlock_bh(&im->lock);
1194 
1195 	spin_lock_bh(&in_dev->mc_tomb_lock);
1196 	pmc->next = in_dev->mc_tomb;
1197 	in_dev->mc_tomb = pmc;
1198 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1199 }
1200 
1201 /*
1202  * restore ip_mc_list deleted records
1203  */
1204 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1205 {
1206 	struct ip_mc_list *pmc, *pmc_prev;
1207 	struct ip_sf_list *psf;
1208 	struct net *net = dev_net(in_dev->dev);
1209 	__be32 multiaddr = im->multiaddr;
1210 
1211 	spin_lock_bh(&in_dev->mc_tomb_lock);
1212 	pmc_prev = NULL;
1213 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
1214 		if (pmc->multiaddr == multiaddr)
1215 			break;
1216 		pmc_prev = pmc;
1217 	}
1218 	if (pmc) {
1219 		if (pmc_prev)
1220 			pmc_prev->next = pmc->next;
1221 		else
1222 			in_dev->mc_tomb = pmc->next;
1223 	}
1224 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1225 
1226 	spin_lock_bh(&im->lock);
1227 	if (pmc) {
1228 		im->interface = pmc->interface;
1229 		if (im->sfmode == MCAST_INCLUDE) {
1230 			swap(im->tomb, pmc->tomb);
1231 			swap(im->sources, pmc->sources);
1232 			for (psf = im->sources; psf; psf = psf->sf_next)
1233 				psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1234 		} else {
1235 			im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1236 		}
1237 		in_dev_put(pmc->interface);
1238 		kfree_pmc(pmc);
1239 	}
1240 	spin_unlock_bh(&im->lock);
1241 }
1242 
1243 /*
1244  * flush ip_mc_list deleted records
1245  */
1246 static void igmpv3_clear_delrec(struct in_device *in_dev)
1247 {
1248 	struct ip_mc_list *pmc, *nextpmc;
1249 
1250 	spin_lock_bh(&in_dev->mc_tomb_lock);
1251 	pmc = in_dev->mc_tomb;
1252 	in_dev->mc_tomb = NULL;
1253 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1254 
1255 	for (; pmc; pmc = nextpmc) {
1256 		nextpmc = pmc->next;
1257 		ip_mc_clear_src(pmc);
1258 		in_dev_put(pmc->interface);
1259 		kfree_pmc(pmc);
1260 	}
1261 	/* clear dead sources, too */
1262 	rcu_read_lock();
1263 	for_each_pmc_rcu(in_dev, pmc) {
1264 		struct ip_sf_list *psf;
1265 
1266 		spin_lock_bh(&pmc->lock);
1267 		psf = pmc->tomb;
1268 		pmc->tomb = NULL;
1269 		spin_unlock_bh(&pmc->lock);
1270 		ip_sf_list_clear_all(psf);
1271 	}
1272 	rcu_read_unlock();
1273 }
1274 #endif
1275 
1276 static void __igmp_group_dropped(struct ip_mc_list *im, gfp_t gfp)
1277 {
1278 	struct in_device *in_dev = im->interface;
1279 #ifdef CONFIG_IP_MULTICAST
1280 	struct net *net = dev_net(in_dev->dev);
1281 	int reporter;
1282 #endif
1283 
1284 	if (im->loaded) {
1285 		im->loaded = 0;
1286 		ip_mc_filter_del(in_dev, im->multiaddr);
1287 	}
1288 
1289 #ifdef CONFIG_IP_MULTICAST
1290 	if (im->multiaddr == IGMP_ALL_HOSTS)
1291 		return;
1292 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1293 		return;
1294 
1295 	reporter = im->reporter;
1296 	igmp_stop_timer(im);
1297 
1298 	if (!in_dev->dead) {
1299 		if (IGMP_V1_SEEN(in_dev))
1300 			return;
1301 		if (IGMP_V2_SEEN(in_dev)) {
1302 			if (reporter)
1303 				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
1304 			return;
1305 		}
1306 		/* IGMPv3 */
1307 		igmpv3_add_delrec(in_dev, im, gfp);
1308 
1309 		igmp_ifc_event(in_dev);
1310 	}
1311 #endif
1312 }
1313 
1314 static void igmp_group_dropped(struct ip_mc_list *im)
1315 {
1316 	__igmp_group_dropped(im, GFP_KERNEL);
1317 }
1318 
1319 static void igmp_group_added(struct ip_mc_list *im)
1320 {
1321 	struct in_device *in_dev = im->interface;
1322 #ifdef CONFIG_IP_MULTICAST
1323 	struct net *net = dev_net(in_dev->dev);
1324 #endif
1325 
1326 	if (im->loaded == 0) {
1327 		im->loaded = 1;
1328 		ip_mc_filter_add(in_dev, im->multiaddr);
1329 	}
1330 
1331 #ifdef CONFIG_IP_MULTICAST
1332 	if (im->multiaddr == IGMP_ALL_HOSTS)
1333 		return;
1334 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1335 		return;
1336 
1337 	if (in_dev->dead)
1338 		return;
1339 
1340 	im->unsolicit_count = net->ipv4.sysctl_igmp_qrv;
1341 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
1342 		spin_lock_bh(&im->lock);
1343 		igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
1344 		spin_unlock_bh(&im->lock);
1345 		return;
1346 	}
1347 	/* else, v3 */
1348 
1349 	/* Based on RFC3376 5.1, for newly added INCLUDE SSM, we should
1350 	 * not send filter-mode change record as the mode should be from
1351 	 * IN() to IN(A).
1352 	 */
1353 	if (im->sfmode == MCAST_EXCLUDE)
1354 		im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1355 
1356 	igmp_ifc_event(in_dev);
1357 #endif
1358 }
1359 
1360 
1361 /*
1362  *	Multicast list managers
1363  */
1364 
1365 static u32 ip_mc_hash(const struct ip_mc_list *im)
1366 {
1367 	return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
1368 }
1369 
1370 static void ip_mc_hash_add(struct in_device *in_dev,
1371 			   struct ip_mc_list *im)
1372 {
1373 	struct ip_mc_list __rcu **mc_hash;
1374 	u32 hash;
1375 
1376 	mc_hash = rtnl_dereference(in_dev->mc_hash);
1377 	if (mc_hash) {
1378 		hash = ip_mc_hash(im);
1379 		im->next_hash = mc_hash[hash];
1380 		rcu_assign_pointer(mc_hash[hash], im);
1381 		return;
1382 	}
1383 
1384 	/* do not use a hash table for small number of items */
1385 	if (in_dev->mc_count < 4)
1386 		return;
1387 
1388 	mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
1389 			  GFP_KERNEL);
1390 	if (!mc_hash)
1391 		return;
1392 
1393 	for_each_pmc_rtnl(in_dev, im) {
1394 		hash = ip_mc_hash(im);
1395 		im->next_hash = mc_hash[hash];
1396 		RCU_INIT_POINTER(mc_hash[hash], im);
1397 	}
1398 
1399 	rcu_assign_pointer(in_dev->mc_hash, mc_hash);
1400 }
1401 
1402 static void ip_mc_hash_remove(struct in_device *in_dev,
1403 			      struct ip_mc_list *im)
1404 {
1405 	struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
1406 	struct ip_mc_list *aux;
1407 
1408 	if (!mc_hash)
1409 		return;
1410 	mc_hash += ip_mc_hash(im);
1411 	while ((aux = rtnl_dereference(*mc_hash)) != im)
1412 		mc_hash = &aux->next_hash;
1413 	*mc_hash = im->next_hash;
1414 }
1415 
1416 
1417 /*
1418  *	A socket has joined a multicast group on device dev.
1419  */
1420 static void ____ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
1421 				unsigned int mode, gfp_t gfp)
1422 {
1423 	struct ip_mc_list *im;
1424 
1425 	ASSERT_RTNL();
1426 
1427 	for_each_pmc_rtnl(in_dev, im) {
1428 		if (im->multiaddr == addr) {
1429 			im->users++;
1430 			ip_mc_add_src(in_dev, &addr, mode, 0, NULL, 0);
1431 			goto out;
1432 		}
1433 	}
1434 
1435 	im = kzalloc(sizeof(*im), gfp);
1436 	if (!im)
1437 		goto out;
1438 
1439 	im->users = 1;
1440 	im->interface = in_dev;
1441 	in_dev_hold(in_dev);
1442 	im->multiaddr = addr;
1443 	/* initial mode is (EX, empty) */
1444 	im->sfmode = mode;
1445 	im->sfcount[mode] = 1;
1446 	refcount_set(&im->refcnt, 1);
1447 	spin_lock_init(&im->lock);
1448 #ifdef CONFIG_IP_MULTICAST
1449 	timer_setup(&im->timer, igmp_timer_expire, 0);
1450 #endif
1451 
1452 	im->next_rcu = in_dev->mc_list;
1453 	in_dev->mc_count++;
1454 	rcu_assign_pointer(in_dev->mc_list, im);
1455 
1456 	ip_mc_hash_add(in_dev, im);
1457 
1458 #ifdef CONFIG_IP_MULTICAST
1459 	igmpv3_del_delrec(in_dev, im);
1460 #endif
1461 	igmp_group_added(im);
1462 	if (!in_dev->dead)
1463 		ip_rt_multicast_event(in_dev);
1464 out:
1465 	return;
1466 }
1467 
1468 void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
1469 {
1470 	____ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE, gfp);
1471 }
1472 EXPORT_SYMBOL(__ip_mc_inc_group);
1473 
1474 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
1475 {
1476 	__ip_mc_inc_group(in_dev, addr, GFP_KERNEL);
1477 }
1478 EXPORT_SYMBOL(ip_mc_inc_group);
1479 
1480 static int ip_mc_check_iphdr(struct sk_buff *skb)
1481 {
1482 	const struct iphdr *iph;
1483 	unsigned int len;
1484 	unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
1485 
1486 	if (!pskb_may_pull(skb, offset))
1487 		return -EINVAL;
1488 
1489 	iph = ip_hdr(skb);
1490 
1491 	if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
1492 		return -EINVAL;
1493 
1494 	offset += ip_hdrlen(skb) - sizeof(*iph);
1495 
1496 	if (!pskb_may_pull(skb, offset))
1497 		return -EINVAL;
1498 
1499 	iph = ip_hdr(skb);
1500 
1501 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1502 		return -EINVAL;
1503 
1504 	len = skb_network_offset(skb) + ntohs(iph->tot_len);
1505 	if (skb->len < len || len < offset)
1506 		return -EINVAL;
1507 
1508 	skb_set_transport_header(skb, offset);
1509 
1510 	return 0;
1511 }
1512 
1513 static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
1514 {
1515 	unsigned int len = skb_transport_offset(skb);
1516 
1517 	len += sizeof(struct igmpv3_report);
1518 
1519 	return ip_mc_may_pull(skb, len) ? 0 : -EINVAL;
1520 }
1521 
1522 static int ip_mc_check_igmp_query(struct sk_buff *skb)
1523 {
1524 	unsigned int transport_len = ip_transport_len(skb);
1525 	unsigned int len;
1526 
1527 	/* IGMPv{1,2}? */
1528 	if (transport_len != sizeof(struct igmphdr)) {
1529 		/* or IGMPv3? */
1530 		if (transport_len < sizeof(struct igmpv3_query))
1531 			return -EINVAL;
1532 
1533 		len = skb_transport_offset(skb) + sizeof(struct igmpv3_query);
1534 		if (!ip_mc_may_pull(skb, len))
1535 			return -EINVAL;
1536 	}
1537 
1538 	/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
1539 	 * all-systems destination addresses (224.0.0.1) for general queries
1540 	 */
1541 	if (!igmp_hdr(skb)->group &&
1542 	    ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
1543 		return -EINVAL;
1544 
1545 	return 0;
1546 }
1547 
1548 static int ip_mc_check_igmp_msg(struct sk_buff *skb)
1549 {
1550 	switch (igmp_hdr(skb)->type) {
1551 	case IGMP_HOST_LEAVE_MESSAGE:
1552 	case IGMP_HOST_MEMBERSHIP_REPORT:
1553 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1554 		return 0;
1555 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1556 		return ip_mc_check_igmp_reportv3(skb);
1557 	case IGMP_HOST_MEMBERSHIP_QUERY:
1558 		return ip_mc_check_igmp_query(skb);
1559 	default:
1560 		return -ENOMSG;
1561 	}
1562 }
1563 
1564 static __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
1565 {
1566 	return skb_checksum_simple_validate(skb);
1567 }
1568 
1569 static int ip_mc_check_igmp_csum(struct sk_buff *skb)
1570 {
1571 	unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
1572 	unsigned int transport_len = ip_transport_len(skb);
1573 	struct sk_buff *skb_chk;
1574 
1575 	if (!ip_mc_may_pull(skb, len))
1576 		return -EINVAL;
1577 
1578 	skb_chk = skb_checksum_trimmed(skb, transport_len,
1579 				       ip_mc_validate_checksum);
1580 	if (!skb_chk)
1581 		return -EINVAL;
1582 
1583 	if (skb_chk != skb)
1584 		kfree_skb(skb_chk);
1585 
1586 	return 0;
1587 }
1588 
1589 /**
1590  * ip_mc_check_igmp - checks whether this is a sane IGMP packet
1591  * @skb: the skb to validate
1592  *
1593  * Checks whether an IPv4 packet is a valid IGMP packet. If so sets
1594  * skb transport header accordingly and returns zero.
1595  *
1596  * -EINVAL: A broken packet was detected, i.e. it violates some internet
1597  *  standard
1598  * -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
1599  * -ENOMEM: A memory allocation failure happened.
1600  *
1601  * Caller needs to set the skb network header and free any returned skb if it
1602  * differs from the provided skb.
1603  */
1604 int ip_mc_check_igmp(struct sk_buff *skb)
1605 {
1606 	int ret = ip_mc_check_iphdr(skb);
1607 
1608 	if (ret < 0)
1609 		return ret;
1610 
1611 	if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
1612 		return -ENOMSG;
1613 
1614 	ret = ip_mc_check_igmp_csum(skb);
1615 	if (ret < 0)
1616 		return ret;
1617 
1618 	return ip_mc_check_igmp_msg(skb);
1619 }
1620 EXPORT_SYMBOL(ip_mc_check_igmp);
1621 
1622 /*
1623  *	Resend IGMP JOIN report; used by netdev notifier.
1624  */
1625 static void ip_mc_rejoin_groups(struct in_device *in_dev)
1626 {
1627 #ifdef CONFIG_IP_MULTICAST
1628 	struct ip_mc_list *im;
1629 	int type;
1630 	struct net *net = dev_net(in_dev->dev);
1631 
1632 	ASSERT_RTNL();
1633 
1634 	for_each_pmc_rtnl(in_dev, im) {
1635 		if (im->multiaddr == IGMP_ALL_HOSTS)
1636 			continue;
1637 		if (ipv4_is_local_multicast(im->multiaddr) &&
1638 		    !net->ipv4.sysctl_igmp_llm_reports)
1639 			continue;
1640 
1641 		/* a failover is happening and switches
1642 		 * must be notified immediately
1643 		 */
1644 		if (IGMP_V1_SEEN(in_dev))
1645 			type = IGMP_HOST_MEMBERSHIP_REPORT;
1646 		else if (IGMP_V2_SEEN(in_dev))
1647 			type = IGMPV2_HOST_MEMBERSHIP_REPORT;
1648 		else
1649 			type = IGMPV3_HOST_MEMBERSHIP_REPORT;
1650 		igmp_send_report(in_dev, im, type);
1651 	}
1652 #endif
1653 }
1654 
1655 /*
1656  *	A socket has left a multicast group on device dev
1657  */
1658 
1659 void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
1660 {
1661 	struct ip_mc_list *i;
1662 	struct ip_mc_list __rcu **ip;
1663 
1664 	ASSERT_RTNL();
1665 
1666 	for (ip = &in_dev->mc_list;
1667 	     (i = rtnl_dereference(*ip)) != NULL;
1668 	     ip = &i->next_rcu) {
1669 		if (i->multiaddr == addr) {
1670 			if (--i->users == 0) {
1671 				ip_mc_hash_remove(in_dev, i);
1672 				*ip = i->next_rcu;
1673 				in_dev->mc_count--;
1674 				__igmp_group_dropped(i, gfp);
1675 				ip_mc_clear_src(i);
1676 
1677 				if (!in_dev->dead)
1678 					ip_rt_multicast_event(in_dev);
1679 
1680 				ip_ma_put(i);
1681 				return;
1682 			}
1683 			break;
1684 		}
1685 	}
1686 }
1687 EXPORT_SYMBOL(__ip_mc_dec_group);
1688 
1689 /* Device changing type */
1690 
1691 void ip_mc_unmap(struct in_device *in_dev)
1692 {
1693 	struct ip_mc_list *pmc;
1694 
1695 	ASSERT_RTNL();
1696 
1697 	for_each_pmc_rtnl(in_dev, pmc)
1698 		igmp_group_dropped(pmc);
1699 }
1700 
1701 void ip_mc_remap(struct in_device *in_dev)
1702 {
1703 	struct ip_mc_list *pmc;
1704 
1705 	ASSERT_RTNL();
1706 
1707 	for_each_pmc_rtnl(in_dev, pmc) {
1708 #ifdef CONFIG_IP_MULTICAST
1709 		igmpv3_del_delrec(in_dev, pmc);
1710 #endif
1711 		igmp_group_added(pmc);
1712 	}
1713 }
1714 
1715 /* Device going down */
1716 
1717 void ip_mc_down(struct in_device *in_dev)
1718 {
1719 	struct ip_mc_list *pmc;
1720 
1721 	ASSERT_RTNL();
1722 
1723 	for_each_pmc_rtnl(in_dev, pmc)
1724 		igmp_group_dropped(pmc);
1725 
1726 #ifdef CONFIG_IP_MULTICAST
1727 	in_dev->mr_ifc_count = 0;
1728 	if (del_timer(&in_dev->mr_ifc_timer))
1729 		__in_dev_put(in_dev);
1730 	in_dev->mr_gq_running = 0;
1731 	if (del_timer(&in_dev->mr_gq_timer))
1732 		__in_dev_put(in_dev);
1733 #endif
1734 
1735 	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
1736 }
1737 
1738 #ifdef CONFIG_IP_MULTICAST
1739 static void ip_mc_reset(struct in_device *in_dev)
1740 {
1741 	struct net *net = dev_net(in_dev->dev);
1742 
1743 	in_dev->mr_qi = IGMP_QUERY_INTERVAL;
1744 	in_dev->mr_qri = IGMP_QUERY_RESPONSE_INTERVAL;
1745 	in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
1746 }
1747 #else
1748 static void ip_mc_reset(struct in_device *in_dev)
1749 {
1750 }
1751 #endif
1752 
1753 void ip_mc_init_dev(struct in_device *in_dev)
1754 {
1755 	ASSERT_RTNL();
1756 
1757 #ifdef CONFIG_IP_MULTICAST
1758 	timer_setup(&in_dev->mr_gq_timer, igmp_gq_timer_expire, 0);
1759 	timer_setup(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire, 0);
1760 #endif
1761 	ip_mc_reset(in_dev);
1762 
1763 	spin_lock_init(&in_dev->mc_tomb_lock);
1764 }
1765 
1766 /* Device going up */
1767 
1768 void ip_mc_up(struct in_device *in_dev)
1769 {
1770 	struct ip_mc_list *pmc;
1771 
1772 	ASSERT_RTNL();
1773 
1774 	ip_mc_reset(in_dev);
1775 	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
1776 
1777 	for_each_pmc_rtnl(in_dev, pmc) {
1778 #ifdef CONFIG_IP_MULTICAST
1779 		igmpv3_del_delrec(in_dev, pmc);
1780 #endif
1781 		igmp_group_added(pmc);
1782 	}
1783 }
1784 
1785 /*
1786  *	Device is about to be destroyed: clean up.
1787  */
1788 
1789 void ip_mc_destroy_dev(struct in_device *in_dev)
1790 {
1791 	struct ip_mc_list *i;
1792 
1793 	ASSERT_RTNL();
1794 
1795 	/* Deactivate timers */
1796 	ip_mc_down(in_dev);
1797 #ifdef CONFIG_IP_MULTICAST
1798 	igmpv3_clear_delrec(in_dev);
1799 #endif
1800 
1801 	while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
1802 		in_dev->mc_list = i->next_rcu;
1803 		in_dev->mc_count--;
1804 		ip_mc_clear_src(i);
1805 		ip_ma_put(i);
1806 	}
1807 }
1808 
1809 /* RTNL is locked */
1810 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1811 {
1812 	struct net_device *dev = NULL;
1813 	struct in_device *idev = NULL;
1814 
1815 	if (imr->imr_ifindex) {
1816 		idev = inetdev_by_index(net, imr->imr_ifindex);
1817 		return idev;
1818 	}
1819 	if (imr->imr_address.s_addr) {
1820 		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1821 		if (!dev)
1822 			return NULL;
1823 	}
1824 
1825 	if (!dev) {
1826 		struct rtable *rt = ip_route_output(net,
1827 						    imr->imr_multiaddr.s_addr,
1828 						    0, 0, 0);
1829 		if (!IS_ERR(rt)) {
1830 			dev = rt->dst.dev;
1831 			ip_rt_put(rt);
1832 		}
1833 	}
1834 	if (dev) {
1835 		imr->imr_ifindex = dev->ifindex;
1836 		idev = __in_dev_get_rtnl(dev);
1837 	}
1838 	return idev;
1839 }
1840 
1841 /*
1842  *	Join a socket to a group
1843  */
1844 
1845 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1846 	__be32 *psfsrc)
1847 {
1848 	struct ip_sf_list *psf, *psf_prev;
1849 	int rv = 0;
1850 
1851 	psf_prev = NULL;
1852 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1853 		if (psf->sf_inaddr == *psfsrc)
1854 			break;
1855 		psf_prev = psf;
1856 	}
1857 	if (!psf || psf->sf_count[sfmode] == 0) {
1858 		/* source filter not found, or count wrong =>  bug */
1859 		return -ESRCH;
1860 	}
1861 	psf->sf_count[sfmode]--;
1862 	if (psf->sf_count[sfmode] == 0) {
1863 		ip_rt_multicast_event(pmc->interface);
1864 	}
1865 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1866 #ifdef CONFIG_IP_MULTICAST
1867 		struct in_device *in_dev = pmc->interface;
1868 		struct net *net = dev_net(in_dev->dev);
1869 #endif
1870 
1871 		/* no more filters for this source */
1872 		if (psf_prev)
1873 			psf_prev->sf_next = psf->sf_next;
1874 		else
1875 			pmc->sources = psf->sf_next;
1876 #ifdef CONFIG_IP_MULTICAST
1877 		if (psf->sf_oldin &&
1878 		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1879 			psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1880 			psf->sf_next = pmc->tomb;
1881 			pmc->tomb = psf;
1882 			rv = 1;
1883 		} else
1884 #endif
1885 			kfree(psf);
1886 	}
1887 	return rv;
1888 }
1889 
1890 #ifndef CONFIG_IP_MULTICAST
1891 #define igmp_ifc_event(x)	do { } while (0)
1892 #endif
1893 
1894 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1895 			 int sfcount, __be32 *psfsrc, int delta)
1896 {
1897 	struct ip_mc_list *pmc;
1898 	int	changerec = 0;
1899 	int	i, err;
1900 
1901 	if (!in_dev)
1902 		return -ENODEV;
1903 	rcu_read_lock();
1904 	for_each_pmc_rcu(in_dev, pmc) {
1905 		if (*pmca == pmc->multiaddr)
1906 			break;
1907 	}
1908 	if (!pmc) {
1909 		/* MCA not found?? bug */
1910 		rcu_read_unlock();
1911 		return -ESRCH;
1912 	}
1913 	spin_lock_bh(&pmc->lock);
1914 	rcu_read_unlock();
1915 #ifdef CONFIG_IP_MULTICAST
1916 	sf_markstate(pmc);
1917 #endif
1918 	if (!delta) {
1919 		err = -EINVAL;
1920 		if (!pmc->sfcount[sfmode])
1921 			goto out_unlock;
1922 		pmc->sfcount[sfmode]--;
1923 	}
1924 	err = 0;
1925 	for (i = 0; i < sfcount; i++) {
1926 		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1927 
1928 		changerec |= rv > 0;
1929 		if (!err && rv < 0)
1930 			err = rv;
1931 	}
1932 	if (pmc->sfmode == MCAST_EXCLUDE &&
1933 	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1934 	    pmc->sfcount[MCAST_INCLUDE]) {
1935 #ifdef CONFIG_IP_MULTICAST
1936 		struct ip_sf_list *psf;
1937 		struct net *net = dev_net(in_dev->dev);
1938 #endif
1939 
1940 		/* filter mode change */
1941 		pmc->sfmode = MCAST_INCLUDE;
1942 #ifdef CONFIG_IP_MULTICAST
1943 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1944 		in_dev->mr_ifc_count = pmc->crcount;
1945 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1946 			psf->sf_crcount = 0;
1947 		igmp_ifc_event(pmc->interface);
1948 	} else if (sf_setstate(pmc) || changerec) {
1949 		igmp_ifc_event(pmc->interface);
1950 #endif
1951 	}
1952 out_unlock:
1953 	spin_unlock_bh(&pmc->lock);
1954 	return err;
1955 }
1956 
1957 /*
1958  * Add multicast single-source filter to the interface list
1959  */
1960 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1961 	__be32 *psfsrc)
1962 {
1963 	struct ip_sf_list *psf, *psf_prev;
1964 
1965 	psf_prev = NULL;
1966 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1967 		if (psf->sf_inaddr == *psfsrc)
1968 			break;
1969 		psf_prev = psf;
1970 	}
1971 	if (!psf) {
1972 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1973 		if (!psf)
1974 			return -ENOBUFS;
1975 		psf->sf_inaddr = *psfsrc;
1976 		if (psf_prev) {
1977 			psf_prev->sf_next = psf;
1978 		} else
1979 			pmc->sources = psf;
1980 	}
1981 	psf->sf_count[sfmode]++;
1982 	if (psf->sf_count[sfmode] == 1) {
1983 		ip_rt_multicast_event(pmc->interface);
1984 	}
1985 	return 0;
1986 }
1987 
1988 #ifdef CONFIG_IP_MULTICAST
1989 static void sf_markstate(struct ip_mc_list *pmc)
1990 {
1991 	struct ip_sf_list *psf;
1992 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1993 
1994 	for (psf = pmc->sources; psf; psf = psf->sf_next)
1995 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1996 			psf->sf_oldin = mca_xcount ==
1997 				psf->sf_count[MCAST_EXCLUDE] &&
1998 				!psf->sf_count[MCAST_INCLUDE];
1999 		} else
2000 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
2001 }
2002 
2003 static int sf_setstate(struct ip_mc_list *pmc)
2004 {
2005 	struct ip_sf_list *psf, *dpsf;
2006 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
2007 	int qrv = pmc->interface->mr_qrv;
2008 	int new_in, rv;
2009 
2010 	rv = 0;
2011 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
2012 		if (pmc->sfcount[MCAST_EXCLUDE]) {
2013 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
2014 				!psf->sf_count[MCAST_INCLUDE];
2015 		} else
2016 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
2017 		if (new_in) {
2018 			if (!psf->sf_oldin) {
2019 				struct ip_sf_list *prev = NULL;
2020 
2021 				for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
2022 					if (dpsf->sf_inaddr == psf->sf_inaddr)
2023 						break;
2024 					prev = dpsf;
2025 				}
2026 				if (dpsf) {
2027 					if (prev)
2028 						prev->sf_next = dpsf->sf_next;
2029 					else
2030 						pmc->tomb = dpsf->sf_next;
2031 					kfree(dpsf);
2032 				}
2033 				psf->sf_crcount = qrv;
2034 				rv++;
2035 			}
2036 		} else if (psf->sf_oldin) {
2037 
2038 			psf->sf_crcount = 0;
2039 			/*
2040 			 * add or update "delete" records if an active filter
2041 			 * is now inactive
2042 			 */
2043 			for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
2044 				if (dpsf->sf_inaddr == psf->sf_inaddr)
2045 					break;
2046 			if (!dpsf) {
2047 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
2048 				if (!dpsf)
2049 					continue;
2050 				*dpsf = *psf;
2051 				/* pmc->lock held by callers */
2052 				dpsf->sf_next = pmc->tomb;
2053 				pmc->tomb = dpsf;
2054 			}
2055 			dpsf->sf_crcount = qrv;
2056 			rv++;
2057 		}
2058 	}
2059 	return rv;
2060 }
2061 #endif
2062 
2063 /*
2064  * Add multicast source filter list to the interface list
2065  */
2066 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
2067 			 int sfcount, __be32 *psfsrc, int delta)
2068 {
2069 	struct ip_mc_list *pmc;
2070 	int	isexclude;
2071 	int	i, err;
2072 
2073 	if (!in_dev)
2074 		return -ENODEV;
2075 	rcu_read_lock();
2076 	for_each_pmc_rcu(in_dev, pmc) {
2077 		if (*pmca == pmc->multiaddr)
2078 			break;
2079 	}
2080 	if (!pmc) {
2081 		/* MCA not found?? bug */
2082 		rcu_read_unlock();
2083 		return -ESRCH;
2084 	}
2085 	spin_lock_bh(&pmc->lock);
2086 	rcu_read_unlock();
2087 
2088 #ifdef CONFIG_IP_MULTICAST
2089 	sf_markstate(pmc);
2090 #endif
2091 	isexclude = pmc->sfmode == MCAST_EXCLUDE;
2092 	if (!delta)
2093 		pmc->sfcount[sfmode]++;
2094 	err = 0;
2095 	for (i = 0; i < sfcount; i++) {
2096 		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2097 		if (err)
2098 			break;
2099 	}
2100 	if (err) {
2101 		int j;
2102 
2103 		if (!delta)
2104 			pmc->sfcount[sfmode]--;
2105 		for (j = 0; j < i; j++)
2106 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2107 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
2108 #ifdef CONFIG_IP_MULTICAST
2109 		struct ip_sf_list *psf;
2110 		struct net *net = dev_net(pmc->interface->dev);
2111 		in_dev = pmc->interface;
2112 #endif
2113 
2114 		/* filter mode change */
2115 		if (pmc->sfcount[MCAST_EXCLUDE])
2116 			pmc->sfmode = MCAST_EXCLUDE;
2117 		else if (pmc->sfcount[MCAST_INCLUDE])
2118 			pmc->sfmode = MCAST_INCLUDE;
2119 #ifdef CONFIG_IP_MULTICAST
2120 		/* else no filters; keep old mode for reports */
2121 
2122 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
2123 		in_dev->mr_ifc_count = pmc->crcount;
2124 		for (psf = pmc->sources; psf; psf = psf->sf_next)
2125 			psf->sf_crcount = 0;
2126 		igmp_ifc_event(in_dev);
2127 	} else if (sf_setstate(pmc)) {
2128 		igmp_ifc_event(in_dev);
2129 #endif
2130 	}
2131 	spin_unlock_bh(&pmc->lock);
2132 	return err;
2133 }
2134 
2135 static void ip_mc_clear_src(struct ip_mc_list *pmc)
2136 {
2137 	struct ip_sf_list *tomb, *sources;
2138 
2139 	spin_lock_bh(&pmc->lock);
2140 	tomb = pmc->tomb;
2141 	pmc->tomb = NULL;
2142 	sources = pmc->sources;
2143 	pmc->sources = NULL;
2144 	pmc->sfmode = MCAST_EXCLUDE;
2145 	pmc->sfcount[MCAST_INCLUDE] = 0;
2146 	pmc->sfcount[MCAST_EXCLUDE] = 1;
2147 	spin_unlock_bh(&pmc->lock);
2148 
2149 	ip_sf_list_clear_all(tomb);
2150 	ip_sf_list_clear_all(sources);
2151 }
2152 
2153 /* Join a multicast group
2154  */
2155 static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
2156 			      unsigned int mode)
2157 {
2158 	__be32 addr = imr->imr_multiaddr.s_addr;
2159 	struct ip_mc_socklist *iml, *i;
2160 	struct in_device *in_dev;
2161 	struct inet_sock *inet = inet_sk(sk);
2162 	struct net *net = sock_net(sk);
2163 	int ifindex;
2164 	int count = 0;
2165 	int err;
2166 
2167 	ASSERT_RTNL();
2168 
2169 	if (!ipv4_is_multicast(addr))
2170 		return -EINVAL;
2171 
2172 	in_dev = ip_mc_find_dev(net, imr);
2173 
2174 	if (!in_dev) {
2175 		err = -ENODEV;
2176 		goto done;
2177 	}
2178 
2179 	err = -EADDRINUSE;
2180 	ifindex = imr->imr_ifindex;
2181 	for_each_pmc_rtnl(inet, i) {
2182 		if (i->multi.imr_multiaddr.s_addr == addr &&
2183 		    i->multi.imr_ifindex == ifindex)
2184 			goto done;
2185 		count++;
2186 	}
2187 	err = -ENOBUFS;
2188 	if (count >= net->ipv4.sysctl_igmp_max_memberships)
2189 		goto done;
2190 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
2191 	if (!iml)
2192 		goto done;
2193 
2194 	memcpy(&iml->multi, imr, sizeof(*imr));
2195 	iml->next_rcu = inet->mc_list;
2196 	iml->sflist = NULL;
2197 	iml->sfmode = mode;
2198 	rcu_assign_pointer(inet->mc_list, iml);
2199 	____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL);
2200 	err = 0;
2201 done:
2202 	return err;
2203 }
2204 
2205 /* Join ASM (Any-Source Multicast) group
2206  */
2207 int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
2208 {
2209 	return __ip_mc_join_group(sk, imr, MCAST_EXCLUDE);
2210 }
2211 EXPORT_SYMBOL(ip_mc_join_group);
2212 
2213 /* Join SSM (Source-Specific Multicast) group
2214  */
2215 int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
2216 			 unsigned int mode)
2217 {
2218 	return __ip_mc_join_group(sk, imr, mode);
2219 }
2220 
2221 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
2222 			   struct in_device *in_dev)
2223 {
2224 	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
2225 	int err;
2226 
2227 	if (!psf) {
2228 		/* any-source empty exclude case */
2229 		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2230 			iml->sfmode, 0, NULL, 0);
2231 	}
2232 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2233 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
2234 	RCU_INIT_POINTER(iml->sflist, NULL);
2235 	/* decrease mem now to avoid the memleak warning */
2236 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
2237 	kfree_rcu(psf, rcu);
2238 	return err;
2239 }
2240 
2241 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
2242 {
2243 	struct inet_sock *inet = inet_sk(sk);
2244 	struct ip_mc_socklist *iml;
2245 	struct ip_mc_socklist __rcu **imlp;
2246 	struct in_device *in_dev;
2247 	struct net *net = sock_net(sk);
2248 	__be32 group = imr->imr_multiaddr.s_addr;
2249 	u32 ifindex;
2250 	int ret = -EADDRNOTAVAIL;
2251 
2252 	ASSERT_RTNL();
2253 
2254 	in_dev = ip_mc_find_dev(net, imr);
2255 	if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
2256 		ret = -ENODEV;
2257 		goto out;
2258 	}
2259 	ifindex = imr->imr_ifindex;
2260 	for (imlp = &inet->mc_list;
2261 	     (iml = rtnl_dereference(*imlp)) != NULL;
2262 	     imlp = &iml->next_rcu) {
2263 		if (iml->multi.imr_multiaddr.s_addr != group)
2264 			continue;
2265 		if (ifindex) {
2266 			if (iml->multi.imr_ifindex != ifindex)
2267 				continue;
2268 		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
2269 				iml->multi.imr_address.s_addr)
2270 			continue;
2271 
2272 		(void) ip_mc_leave_src(sk, iml, in_dev);
2273 
2274 		*imlp = iml->next_rcu;
2275 
2276 		if (in_dev)
2277 			ip_mc_dec_group(in_dev, group);
2278 
2279 		/* decrease mem now to avoid the memleak warning */
2280 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2281 		kfree_rcu(iml, rcu);
2282 		return 0;
2283 	}
2284 out:
2285 	return ret;
2286 }
2287 EXPORT_SYMBOL(ip_mc_leave_group);
2288 
2289 int ip_mc_source(int add, int omode, struct sock *sk, struct
2290 	ip_mreq_source *mreqs, int ifindex)
2291 {
2292 	int err;
2293 	struct ip_mreqn imr;
2294 	__be32 addr = mreqs->imr_multiaddr;
2295 	struct ip_mc_socklist *pmc;
2296 	struct in_device *in_dev = NULL;
2297 	struct inet_sock *inet = inet_sk(sk);
2298 	struct ip_sf_socklist *psl;
2299 	struct net *net = sock_net(sk);
2300 	int leavegroup = 0;
2301 	int i, j, rv;
2302 
2303 	if (!ipv4_is_multicast(addr))
2304 		return -EINVAL;
2305 
2306 	ASSERT_RTNL();
2307 
2308 	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
2309 	imr.imr_address.s_addr = mreqs->imr_interface;
2310 	imr.imr_ifindex = ifindex;
2311 	in_dev = ip_mc_find_dev(net, &imr);
2312 
2313 	if (!in_dev) {
2314 		err = -ENODEV;
2315 		goto done;
2316 	}
2317 	err = -EADDRNOTAVAIL;
2318 
2319 	for_each_pmc_rtnl(inet, pmc) {
2320 		if ((pmc->multi.imr_multiaddr.s_addr ==
2321 		     imr.imr_multiaddr.s_addr) &&
2322 		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
2323 			break;
2324 	}
2325 	if (!pmc) {		/* must have a prior join */
2326 		err = -EINVAL;
2327 		goto done;
2328 	}
2329 	/* if a source filter was set, must be the same mode as before */
2330 	if (pmc->sflist) {
2331 		if (pmc->sfmode != omode) {
2332 			err = -EINVAL;
2333 			goto done;
2334 		}
2335 	} else if (pmc->sfmode != omode) {
2336 		/* allow mode switches for empty-set filters */
2337 		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2338 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2339 			NULL, 0);
2340 		pmc->sfmode = omode;
2341 	}
2342 
2343 	psl = rtnl_dereference(pmc->sflist);
2344 	if (!add) {
2345 		if (!psl)
2346 			goto done;	/* err = -EADDRNOTAVAIL */
2347 		rv = !0;
2348 		for (i = 0; i < psl->sl_count; i++) {
2349 			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2350 				sizeof(__be32));
2351 			if (rv == 0)
2352 				break;
2353 		}
2354 		if (rv)		/* source not found */
2355 			goto done;	/* err = -EADDRNOTAVAIL */
2356 
2357 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2358 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2359 			leavegroup = 1;
2360 			goto done;
2361 		}
2362 
2363 		/* update the interface filter */
2364 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2365 			&mreqs->imr_sourceaddr, 1);
2366 
2367 		for (j = i+1; j < psl->sl_count; j++)
2368 			psl->sl_addr[j-1] = psl->sl_addr[j];
2369 		psl->sl_count--;
2370 		err = 0;
2371 		goto done;
2372 	}
2373 	/* else, add a new source to the filter */
2374 
2375 	if (psl && psl->sl_count >= net->ipv4.sysctl_igmp_max_msf) {
2376 		err = -ENOBUFS;
2377 		goto done;
2378 	}
2379 	if (!psl || psl->sl_count == psl->sl_max) {
2380 		struct ip_sf_socklist *newpsl;
2381 		int count = IP_SFBLOCK;
2382 
2383 		if (psl)
2384 			count += psl->sl_max;
2385 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2386 		if (!newpsl) {
2387 			err = -ENOBUFS;
2388 			goto done;
2389 		}
2390 		newpsl->sl_max = count;
2391 		newpsl->sl_count = count - IP_SFBLOCK;
2392 		if (psl) {
2393 			for (i = 0; i < psl->sl_count; i++)
2394 				newpsl->sl_addr[i] = psl->sl_addr[i];
2395 			/* decrease mem now to avoid the memleak warning */
2396 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2397 			kfree_rcu(psl, rcu);
2398 		}
2399 		rcu_assign_pointer(pmc->sflist, newpsl);
2400 		psl = newpsl;
2401 	}
2402 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
2403 	for (i = 0; i < psl->sl_count; i++) {
2404 		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2405 			sizeof(__be32));
2406 		if (rv == 0)
2407 			break;
2408 	}
2409 	if (rv == 0)		/* address already there is an error */
2410 		goto done;
2411 	for (j = psl->sl_count-1; j >= i; j--)
2412 		psl->sl_addr[j+1] = psl->sl_addr[j];
2413 	psl->sl_addr[i] = mreqs->imr_sourceaddr;
2414 	psl->sl_count++;
2415 	err = 0;
2416 	/* update the interface list */
2417 	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2418 		&mreqs->imr_sourceaddr, 1);
2419 done:
2420 	if (leavegroup)
2421 		err = ip_mc_leave_group(sk, &imr);
2422 	return err;
2423 }
2424 
2425 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2426 {
2427 	int err = 0;
2428 	struct ip_mreqn	imr;
2429 	__be32 addr = msf->imsf_multiaddr;
2430 	struct ip_mc_socklist *pmc;
2431 	struct in_device *in_dev;
2432 	struct inet_sock *inet = inet_sk(sk);
2433 	struct ip_sf_socklist *newpsl, *psl;
2434 	struct net *net = sock_net(sk);
2435 	int leavegroup = 0;
2436 
2437 	if (!ipv4_is_multicast(addr))
2438 		return -EINVAL;
2439 	if (msf->imsf_fmode != MCAST_INCLUDE &&
2440 	    msf->imsf_fmode != MCAST_EXCLUDE)
2441 		return -EINVAL;
2442 
2443 	ASSERT_RTNL();
2444 
2445 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2446 	imr.imr_address.s_addr = msf->imsf_interface;
2447 	imr.imr_ifindex = ifindex;
2448 	in_dev = ip_mc_find_dev(net, &imr);
2449 
2450 	if (!in_dev) {
2451 		err = -ENODEV;
2452 		goto done;
2453 	}
2454 
2455 	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2456 	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2457 		leavegroup = 1;
2458 		goto done;
2459 	}
2460 
2461 	for_each_pmc_rtnl(inet, pmc) {
2462 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2463 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2464 			break;
2465 	}
2466 	if (!pmc) {		/* must have a prior join */
2467 		err = -EINVAL;
2468 		goto done;
2469 	}
2470 	if (msf->imsf_numsrc) {
2471 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2472 							   GFP_KERNEL);
2473 		if (!newpsl) {
2474 			err = -ENOBUFS;
2475 			goto done;
2476 		}
2477 		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2478 		memcpy(newpsl->sl_addr, msf->imsf_slist,
2479 			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2480 		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2481 			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2482 		if (err) {
2483 			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2484 			goto done;
2485 		}
2486 	} else {
2487 		newpsl = NULL;
2488 		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2489 				     msf->imsf_fmode, 0, NULL, 0);
2490 	}
2491 	psl = rtnl_dereference(pmc->sflist);
2492 	if (psl) {
2493 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2494 			psl->sl_count, psl->sl_addr, 0);
2495 		/* decrease mem now to avoid the memleak warning */
2496 		atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2497 		kfree_rcu(psl, rcu);
2498 	} else
2499 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2500 			0, NULL, 0);
2501 	rcu_assign_pointer(pmc->sflist, newpsl);
2502 	pmc->sfmode = msf->imsf_fmode;
2503 	err = 0;
2504 done:
2505 	if (leavegroup)
2506 		err = ip_mc_leave_group(sk, &imr);
2507 	return err;
2508 }
2509 
2510 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2511 	struct ip_msfilter __user *optval, int __user *optlen)
2512 {
2513 	int err, len, count, copycount;
2514 	struct ip_mreqn	imr;
2515 	__be32 addr = msf->imsf_multiaddr;
2516 	struct ip_mc_socklist *pmc;
2517 	struct in_device *in_dev;
2518 	struct inet_sock *inet = inet_sk(sk);
2519 	struct ip_sf_socklist *psl;
2520 	struct net *net = sock_net(sk);
2521 
2522 	ASSERT_RTNL();
2523 
2524 	if (!ipv4_is_multicast(addr))
2525 		return -EINVAL;
2526 
2527 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2528 	imr.imr_address.s_addr = msf->imsf_interface;
2529 	imr.imr_ifindex = 0;
2530 	in_dev = ip_mc_find_dev(net, &imr);
2531 
2532 	if (!in_dev) {
2533 		err = -ENODEV;
2534 		goto done;
2535 	}
2536 	err = -EADDRNOTAVAIL;
2537 
2538 	for_each_pmc_rtnl(inet, pmc) {
2539 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2540 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2541 			break;
2542 	}
2543 	if (!pmc)		/* must have a prior join */
2544 		goto done;
2545 	msf->imsf_fmode = pmc->sfmode;
2546 	psl = rtnl_dereference(pmc->sflist);
2547 	if (!psl) {
2548 		len = 0;
2549 		count = 0;
2550 	} else {
2551 		count = psl->sl_count;
2552 	}
2553 	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2554 	len = copycount * sizeof(psl->sl_addr[0]);
2555 	msf->imsf_numsrc = count;
2556 	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2557 	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2558 		return -EFAULT;
2559 	}
2560 	if (len &&
2561 	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2562 		return -EFAULT;
2563 	return 0;
2564 done:
2565 	return err;
2566 }
2567 
2568 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2569 	struct sockaddr_storage __user *p)
2570 {
2571 	int i, count, copycount;
2572 	struct sockaddr_in *psin;
2573 	__be32 addr;
2574 	struct ip_mc_socklist *pmc;
2575 	struct inet_sock *inet = inet_sk(sk);
2576 	struct ip_sf_socklist *psl;
2577 
2578 	ASSERT_RTNL();
2579 
2580 	psin = (struct sockaddr_in *)&gsf->gf_group;
2581 	if (psin->sin_family != AF_INET)
2582 		return -EINVAL;
2583 	addr = psin->sin_addr.s_addr;
2584 	if (!ipv4_is_multicast(addr))
2585 		return -EINVAL;
2586 
2587 	for_each_pmc_rtnl(inet, pmc) {
2588 		if (pmc->multi.imr_multiaddr.s_addr == addr &&
2589 		    pmc->multi.imr_ifindex == gsf->gf_interface)
2590 			break;
2591 	}
2592 	if (!pmc)		/* must have a prior join */
2593 		return -EADDRNOTAVAIL;
2594 	gsf->gf_fmode = pmc->sfmode;
2595 	psl = rtnl_dereference(pmc->sflist);
2596 	count = psl ? psl->sl_count : 0;
2597 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2598 	gsf->gf_numsrc = count;
2599 	for (i = 0; i < copycount; i++, p++) {
2600 		struct sockaddr_storage ss;
2601 
2602 		psin = (struct sockaddr_in *)&ss;
2603 		memset(&ss, 0, sizeof(ss));
2604 		psin->sin_family = AF_INET;
2605 		psin->sin_addr.s_addr = psl->sl_addr[i];
2606 		if (copy_to_user(p, &ss, sizeof(ss)))
2607 			return -EFAULT;
2608 	}
2609 	return 0;
2610 }
2611 
2612 /*
2613  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2614  */
2615 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
2616 		   int dif, int sdif)
2617 {
2618 	struct inet_sock *inet = inet_sk(sk);
2619 	struct ip_mc_socklist *pmc;
2620 	struct ip_sf_socklist *psl;
2621 	int i;
2622 	int ret;
2623 
2624 	ret = 1;
2625 	if (!ipv4_is_multicast(loc_addr))
2626 		goto out;
2627 
2628 	rcu_read_lock();
2629 	for_each_pmc_rcu(inet, pmc) {
2630 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2631 		    (pmc->multi.imr_ifindex == dif ||
2632 		     (sdif && pmc->multi.imr_ifindex == sdif)))
2633 			break;
2634 	}
2635 	ret = inet->mc_all;
2636 	if (!pmc)
2637 		goto unlock;
2638 	psl = rcu_dereference(pmc->sflist);
2639 	ret = (pmc->sfmode == MCAST_EXCLUDE);
2640 	if (!psl)
2641 		goto unlock;
2642 
2643 	for (i = 0; i < psl->sl_count; i++) {
2644 		if (psl->sl_addr[i] == rmt_addr)
2645 			break;
2646 	}
2647 	ret = 0;
2648 	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2649 		goto unlock;
2650 	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2651 		goto unlock;
2652 	ret = 1;
2653 unlock:
2654 	rcu_read_unlock();
2655 out:
2656 	return ret;
2657 }
2658 
2659 /*
2660  *	A socket is closing.
2661  */
2662 
2663 void ip_mc_drop_socket(struct sock *sk)
2664 {
2665 	struct inet_sock *inet = inet_sk(sk);
2666 	struct ip_mc_socklist *iml;
2667 	struct net *net = sock_net(sk);
2668 
2669 	if (!inet->mc_list)
2670 		return;
2671 
2672 	rtnl_lock();
2673 	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2674 		struct in_device *in_dev;
2675 
2676 		inet->mc_list = iml->next_rcu;
2677 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2678 		(void) ip_mc_leave_src(sk, iml, in_dev);
2679 		if (in_dev)
2680 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2681 		/* decrease mem now to avoid the memleak warning */
2682 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2683 		kfree_rcu(iml, rcu);
2684 	}
2685 	rtnl_unlock();
2686 }
2687 
2688 /* called with rcu_read_lock() */
2689 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
2690 {
2691 	struct ip_mc_list *im;
2692 	struct ip_mc_list __rcu **mc_hash;
2693 	struct ip_sf_list *psf;
2694 	int rv = 0;
2695 
2696 	mc_hash = rcu_dereference(in_dev->mc_hash);
2697 	if (mc_hash) {
2698 		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2699 
2700 		for (im = rcu_dereference(mc_hash[hash]);
2701 		     im != NULL;
2702 		     im = rcu_dereference(im->next_hash)) {
2703 			if (im->multiaddr == mc_addr)
2704 				break;
2705 		}
2706 	} else {
2707 		for_each_pmc_rcu(in_dev, im) {
2708 			if (im->multiaddr == mc_addr)
2709 				break;
2710 		}
2711 	}
2712 	if (im && proto == IPPROTO_IGMP) {
2713 		rv = 1;
2714 	} else if (im) {
2715 		if (src_addr) {
2716 			for (psf = im->sources; psf; psf = psf->sf_next) {
2717 				if (psf->sf_inaddr == src_addr)
2718 					break;
2719 			}
2720 			if (psf)
2721 				rv = psf->sf_count[MCAST_INCLUDE] ||
2722 					psf->sf_count[MCAST_EXCLUDE] !=
2723 					im->sfcount[MCAST_EXCLUDE];
2724 			else
2725 				rv = im->sfcount[MCAST_EXCLUDE] != 0;
2726 		} else
2727 			rv = 1; /* unspecified source; tentatively allow */
2728 	}
2729 	return rv;
2730 }
2731 
2732 #if defined(CONFIG_PROC_FS)
2733 struct igmp_mc_iter_state {
2734 	struct seq_net_private p;
2735 	struct net_device *dev;
2736 	struct in_device *in_dev;
2737 };
2738 
2739 #define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
2740 
2741 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2742 {
2743 	struct net *net = seq_file_net(seq);
2744 	struct ip_mc_list *im = NULL;
2745 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2746 
2747 	state->in_dev = NULL;
2748 	for_each_netdev_rcu(net, state->dev) {
2749 		struct in_device *in_dev;
2750 
2751 		in_dev = __in_dev_get_rcu(state->dev);
2752 		if (!in_dev)
2753 			continue;
2754 		im = rcu_dereference(in_dev->mc_list);
2755 		if (im) {
2756 			state->in_dev = in_dev;
2757 			break;
2758 		}
2759 	}
2760 	return im;
2761 }
2762 
2763 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2764 {
2765 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2766 
2767 	im = rcu_dereference(im->next_rcu);
2768 	while (!im) {
2769 		state->dev = next_net_device_rcu(state->dev);
2770 		if (!state->dev) {
2771 			state->in_dev = NULL;
2772 			break;
2773 		}
2774 		state->in_dev = __in_dev_get_rcu(state->dev);
2775 		if (!state->in_dev)
2776 			continue;
2777 		im = rcu_dereference(state->in_dev->mc_list);
2778 	}
2779 	return im;
2780 }
2781 
2782 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2783 {
2784 	struct ip_mc_list *im = igmp_mc_get_first(seq);
2785 	if (im)
2786 		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2787 			--pos;
2788 	return pos ? NULL : im;
2789 }
2790 
2791 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2792 	__acquires(rcu)
2793 {
2794 	rcu_read_lock();
2795 	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2796 }
2797 
2798 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2799 {
2800 	struct ip_mc_list *im;
2801 	if (v == SEQ_START_TOKEN)
2802 		im = igmp_mc_get_first(seq);
2803 	else
2804 		im = igmp_mc_get_next(seq, v);
2805 	++*pos;
2806 	return im;
2807 }
2808 
2809 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2810 	__releases(rcu)
2811 {
2812 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2813 
2814 	state->in_dev = NULL;
2815 	state->dev = NULL;
2816 	rcu_read_unlock();
2817 }
2818 
2819 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2820 {
2821 	if (v == SEQ_START_TOKEN)
2822 		seq_puts(seq,
2823 			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2824 	else {
2825 		struct ip_mc_list *im = (struct ip_mc_list *)v;
2826 		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2827 		char   *querier;
2828 		long delta;
2829 
2830 #ifdef CONFIG_IP_MULTICAST
2831 		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2832 			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
2833 			  "V3";
2834 #else
2835 		querier = "NONE";
2836 #endif
2837 
2838 		if (rcu_access_pointer(state->in_dev->mc_list) == im) {
2839 			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2840 				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2841 		}
2842 
2843 		delta = im->timer.expires - jiffies;
2844 		seq_printf(seq,
2845 			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2846 			   im->multiaddr, im->users,
2847 			   im->tm_running,
2848 			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2849 			   im->reporter);
2850 	}
2851 	return 0;
2852 }
2853 
2854 static const struct seq_operations igmp_mc_seq_ops = {
2855 	.start	=	igmp_mc_seq_start,
2856 	.next	=	igmp_mc_seq_next,
2857 	.stop	=	igmp_mc_seq_stop,
2858 	.show	=	igmp_mc_seq_show,
2859 };
2860 
2861 struct igmp_mcf_iter_state {
2862 	struct seq_net_private p;
2863 	struct net_device *dev;
2864 	struct in_device *idev;
2865 	struct ip_mc_list *im;
2866 };
2867 
2868 #define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
2869 
2870 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2871 {
2872 	struct net *net = seq_file_net(seq);
2873 	struct ip_sf_list *psf = NULL;
2874 	struct ip_mc_list *im = NULL;
2875 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2876 
2877 	state->idev = NULL;
2878 	state->im = NULL;
2879 	for_each_netdev_rcu(net, state->dev) {
2880 		struct in_device *idev;
2881 		idev = __in_dev_get_rcu(state->dev);
2882 		if (unlikely(!idev))
2883 			continue;
2884 		im = rcu_dereference(idev->mc_list);
2885 		if (likely(im)) {
2886 			spin_lock_bh(&im->lock);
2887 			psf = im->sources;
2888 			if (likely(psf)) {
2889 				state->im = im;
2890 				state->idev = idev;
2891 				break;
2892 			}
2893 			spin_unlock_bh(&im->lock);
2894 		}
2895 	}
2896 	return psf;
2897 }
2898 
2899 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2900 {
2901 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2902 
2903 	psf = psf->sf_next;
2904 	while (!psf) {
2905 		spin_unlock_bh(&state->im->lock);
2906 		state->im = state->im->next;
2907 		while (!state->im) {
2908 			state->dev = next_net_device_rcu(state->dev);
2909 			if (!state->dev) {
2910 				state->idev = NULL;
2911 				goto out;
2912 			}
2913 			state->idev = __in_dev_get_rcu(state->dev);
2914 			if (!state->idev)
2915 				continue;
2916 			state->im = rcu_dereference(state->idev->mc_list);
2917 		}
2918 		if (!state->im)
2919 			break;
2920 		spin_lock_bh(&state->im->lock);
2921 		psf = state->im->sources;
2922 	}
2923 out:
2924 	return psf;
2925 }
2926 
2927 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2928 {
2929 	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2930 	if (psf)
2931 		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2932 			--pos;
2933 	return pos ? NULL : psf;
2934 }
2935 
2936 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2937 	__acquires(rcu)
2938 {
2939 	rcu_read_lock();
2940 	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2941 }
2942 
2943 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2944 {
2945 	struct ip_sf_list *psf;
2946 	if (v == SEQ_START_TOKEN)
2947 		psf = igmp_mcf_get_first(seq);
2948 	else
2949 		psf = igmp_mcf_get_next(seq, v);
2950 	++*pos;
2951 	return psf;
2952 }
2953 
2954 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2955 	__releases(rcu)
2956 {
2957 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2958 	if (likely(state->im)) {
2959 		spin_unlock_bh(&state->im->lock);
2960 		state->im = NULL;
2961 	}
2962 	state->idev = NULL;
2963 	state->dev = NULL;
2964 	rcu_read_unlock();
2965 }
2966 
2967 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2968 {
2969 	struct ip_sf_list *psf = (struct ip_sf_list *)v;
2970 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2971 
2972 	if (v == SEQ_START_TOKEN) {
2973 		seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
2974 	} else {
2975 		seq_printf(seq,
2976 			   "%3d %6.6s 0x%08x "
2977 			   "0x%08x %6lu %6lu\n",
2978 			   state->dev->ifindex, state->dev->name,
2979 			   ntohl(state->im->multiaddr),
2980 			   ntohl(psf->sf_inaddr),
2981 			   psf->sf_count[MCAST_INCLUDE],
2982 			   psf->sf_count[MCAST_EXCLUDE]);
2983 	}
2984 	return 0;
2985 }
2986 
2987 static const struct seq_operations igmp_mcf_seq_ops = {
2988 	.start	=	igmp_mcf_seq_start,
2989 	.next	=	igmp_mcf_seq_next,
2990 	.stop	=	igmp_mcf_seq_stop,
2991 	.show	=	igmp_mcf_seq_show,
2992 };
2993 
2994 static int __net_init igmp_net_init(struct net *net)
2995 {
2996 	struct proc_dir_entry *pde;
2997 	int err;
2998 
2999 	pde = proc_create_net("igmp", 0444, net->proc_net, &igmp_mc_seq_ops,
3000 			sizeof(struct igmp_mc_iter_state));
3001 	if (!pde)
3002 		goto out_igmp;
3003 	pde = proc_create_net("mcfilter", 0444, net->proc_net,
3004 			&igmp_mcf_seq_ops, sizeof(struct igmp_mcf_iter_state));
3005 	if (!pde)
3006 		goto out_mcfilter;
3007 	err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
3008 				   SOCK_DGRAM, 0, net);
3009 	if (err < 0) {
3010 		pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
3011 		       err);
3012 		goto out_sock;
3013 	}
3014 
3015 	return 0;
3016 
3017 out_sock:
3018 	remove_proc_entry("mcfilter", net->proc_net);
3019 out_mcfilter:
3020 	remove_proc_entry("igmp", net->proc_net);
3021 out_igmp:
3022 	return -ENOMEM;
3023 }
3024 
3025 static void __net_exit igmp_net_exit(struct net *net)
3026 {
3027 	remove_proc_entry("mcfilter", net->proc_net);
3028 	remove_proc_entry("igmp", net->proc_net);
3029 	inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
3030 }
3031 
3032 static struct pernet_operations igmp_net_ops = {
3033 	.init = igmp_net_init,
3034 	.exit = igmp_net_exit,
3035 };
3036 #endif
3037 
3038 static int igmp_netdev_event(struct notifier_block *this,
3039 			     unsigned long event, void *ptr)
3040 {
3041 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3042 	struct in_device *in_dev;
3043 
3044 	switch (event) {
3045 	case NETDEV_RESEND_IGMP:
3046 		in_dev = __in_dev_get_rtnl(dev);
3047 		if (in_dev)
3048 			ip_mc_rejoin_groups(in_dev);
3049 		break;
3050 	default:
3051 		break;
3052 	}
3053 	return NOTIFY_DONE;
3054 }
3055 
3056 static struct notifier_block igmp_notifier = {
3057 	.notifier_call = igmp_netdev_event,
3058 };
3059 
3060 int __init igmp_mc_init(void)
3061 {
3062 #if defined(CONFIG_PROC_FS)
3063 	int err;
3064 
3065 	err = register_pernet_subsys(&igmp_net_ops);
3066 	if (err)
3067 		return err;
3068 	err = register_netdevice_notifier(&igmp_notifier);
3069 	if (err)
3070 		goto reg_notif_fail;
3071 	return 0;
3072 
3073 reg_notif_fail:
3074 	unregister_pernet_subsys(&igmp_net_ops);
3075 	return err;
3076 #else
3077 	return register_netdevice_notifier(&igmp_notifier);
3078 #endif
3079 }
3080