xref: /openbmc/linux/net/ipv4/igmp.c (revision e15a5365)
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_ma_put(i);
1805 	}
1806 }
1807 
1808 /* RTNL is locked */
1809 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1810 {
1811 	struct net_device *dev = NULL;
1812 	struct in_device *idev = NULL;
1813 
1814 	if (imr->imr_ifindex) {
1815 		idev = inetdev_by_index(net, imr->imr_ifindex);
1816 		return idev;
1817 	}
1818 	if (imr->imr_address.s_addr) {
1819 		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1820 		if (!dev)
1821 			return NULL;
1822 	}
1823 
1824 	if (!dev) {
1825 		struct rtable *rt = ip_route_output(net,
1826 						    imr->imr_multiaddr.s_addr,
1827 						    0, 0, 0);
1828 		if (!IS_ERR(rt)) {
1829 			dev = rt->dst.dev;
1830 			ip_rt_put(rt);
1831 		}
1832 	}
1833 	if (dev) {
1834 		imr->imr_ifindex = dev->ifindex;
1835 		idev = __in_dev_get_rtnl(dev);
1836 	}
1837 	return idev;
1838 }
1839 
1840 /*
1841  *	Join a socket to a group
1842  */
1843 
1844 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1845 	__be32 *psfsrc)
1846 {
1847 	struct ip_sf_list *psf, *psf_prev;
1848 	int rv = 0;
1849 
1850 	psf_prev = NULL;
1851 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1852 		if (psf->sf_inaddr == *psfsrc)
1853 			break;
1854 		psf_prev = psf;
1855 	}
1856 	if (!psf || psf->sf_count[sfmode] == 0) {
1857 		/* source filter not found, or count wrong =>  bug */
1858 		return -ESRCH;
1859 	}
1860 	psf->sf_count[sfmode]--;
1861 	if (psf->sf_count[sfmode] == 0) {
1862 		ip_rt_multicast_event(pmc->interface);
1863 	}
1864 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1865 #ifdef CONFIG_IP_MULTICAST
1866 		struct in_device *in_dev = pmc->interface;
1867 		struct net *net = dev_net(in_dev->dev);
1868 #endif
1869 
1870 		/* no more filters for this source */
1871 		if (psf_prev)
1872 			psf_prev->sf_next = psf->sf_next;
1873 		else
1874 			pmc->sources = psf->sf_next;
1875 #ifdef CONFIG_IP_MULTICAST
1876 		if (psf->sf_oldin &&
1877 		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1878 			psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1879 			psf->sf_next = pmc->tomb;
1880 			pmc->tomb = psf;
1881 			rv = 1;
1882 		} else
1883 #endif
1884 			kfree(psf);
1885 	}
1886 	return rv;
1887 }
1888 
1889 #ifndef CONFIG_IP_MULTICAST
1890 #define igmp_ifc_event(x)	do { } while (0)
1891 #endif
1892 
1893 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1894 			 int sfcount, __be32 *psfsrc, int delta)
1895 {
1896 	struct ip_mc_list *pmc;
1897 	int	changerec = 0;
1898 	int	i, err;
1899 
1900 	if (!in_dev)
1901 		return -ENODEV;
1902 	rcu_read_lock();
1903 	for_each_pmc_rcu(in_dev, pmc) {
1904 		if (*pmca == pmc->multiaddr)
1905 			break;
1906 	}
1907 	if (!pmc) {
1908 		/* MCA not found?? bug */
1909 		rcu_read_unlock();
1910 		return -ESRCH;
1911 	}
1912 	spin_lock_bh(&pmc->lock);
1913 	rcu_read_unlock();
1914 #ifdef CONFIG_IP_MULTICAST
1915 	sf_markstate(pmc);
1916 #endif
1917 	if (!delta) {
1918 		err = -EINVAL;
1919 		if (!pmc->sfcount[sfmode])
1920 			goto out_unlock;
1921 		pmc->sfcount[sfmode]--;
1922 	}
1923 	err = 0;
1924 	for (i = 0; i < sfcount; i++) {
1925 		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1926 
1927 		changerec |= rv > 0;
1928 		if (!err && rv < 0)
1929 			err = rv;
1930 	}
1931 	if (pmc->sfmode == MCAST_EXCLUDE &&
1932 	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1933 	    pmc->sfcount[MCAST_INCLUDE]) {
1934 #ifdef CONFIG_IP_MULTICAST
1935 		struct ip_sf_list *psf;
1936 		struct net *net = dev_net(in_dev->dev);
1937 #endif
1938 
1939 		/* filter mode change */
1940 		pmc->sfmode = MCAST_INCLUDE;
1941 #ifdef CONFIG_IP_MULTICAST
1942 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1943 		in_dev->mr_ifc_count = pmc->crcount;
1944 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1945 			psf->sf_crcount = 0;
1946 		igmp_ifc_event(pmc->interface);
1947 	} else if (sf_setstate(pmc) || changerec) {
1948 		igmp_ifc_event(pmc->interface);
1949 #endif
1950 	}
1951 out_unlock:
1952 	spin_unlock_bh(&pmc->lock);
1953 	return err;
1954 }
1955 
1956 /*
1957  * Add multicast single-source filter to the interface list
1958  */
1959 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1960 	__be32 *psfsrc)
1961 {
1962 	struct ip_sf_list *psf, *psf_prev;
1963 
1964 	psf_prev = NULL;
1965 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1966 		if (psf->sf_inaddr == *psfsrc)
1967 			break;
1968 		psf_prev = psf;
1969 	}
1970 	if (!psf) {
1971 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1972 		if (!psf)
1973 			return -ENOBUFS;
1974 		psf->sf_inaddr = *psfsrc;
1975 		if (psf_prev) {
1976 			psf_prev->sf_next = psf;
1977 		} else
1978 			pmc->sources = psf;
1979 	}
1980 	psf->sf_count[sfmode]++;
1981 	if (psf->sf_count[sfmode] == 1) {
1982 		ip_rt_multicast_event(pmc->interface);
1983 	}
1984 	return 0;
1985 }
1986 
1987 #ifdef CONFIG_IP_MULTICAST
1988 static void sf_markstate(struct ip_mc_list *pmc)
1989 {
1990 	struct ip_sf_list *psf;
1991 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1992 
1993 	for (psf = pmc->sources; psf; psf = psf->sf_next)
1994 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1995 			psf->sf_oldin = mca_xcount ==
1996 				psf->sf_count[MCAST_EXCLUDE] &&
1997 				!psf->sf_count[MCAST_INCLUDE];
1998 		} else
1999 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
2000 }
2001 
2002 static int sf_setstate(struct ip_mc_list *pmc)
2003 {
2004 	struct ip_sf_list *psf, *dpsf;
2005 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
2006 	int qrv = pmc->interface->mr_qrv;
2007 	int new_in, rv;
2008 
2009 	rv = 0;
2010 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
2011 		if (pmc->sfcount[MCAST_EXCLUDE]) {
2012 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
2013 				!psf->sf_count[MCAST_INCLUDE];
2014 		} else
2015 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
2016 		if (new_in) {
2017 			if (!psf->sf_oldin) {
2018 				struct ip_sf_list *prev = NULL;
2019 
2020 				for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
2021 					if (dpsf->sf_inaddr == psf->sf_inaddr)
2022 						break;
2023 					prev = dpsf;
2024 				}
2025 				if (dpsf) {
2026 					if (prev)
2027 						prev->sf_next = dpsf->sf_next;
2028 					else
2029 						pmc->tomb = dpsf->sf_next;
2030 					kfree(dpsf);
2031 				}
2032 				psf->sf_crcount = qrv;
2033 				rv++;
2034 			}
2035 		} else if (psf->sf_oldin) {
2036 
2037 			psf->sf_crcount = 0;
2038 			/*
2039 			 * add or update "delete" records if an active filter
2040 			 * is now inactive
2041 			 */
2042 			for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
2043 				if (dpsf->sf_inaddr == psf->sf_inaddr)
2044 					break;
2045 			if (!dpsf) {
2046 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
2047 				if (!dpsf)
2048 					continue;
2049 				*dpsf = *psf;
2050 				/* pmc->lock held by callers */
2051 				dpsf->sf_next = pmc->tomb;
2052 				pmc->tomb = dpsf;
2053 			}
2054 			dpsf->sf_crcount = qrv;
2055 			rv++;
2056 		}
2057 	}
2058 	return rv;
2059 }
2060 #endif
2061 
2062 /*
2063  * Add multicast source filter list to the interface list
2064  */
2065 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
2066 			 int sfcount, __be32 *psfsrc, int delta)
2067 {
2068 	struct ip_mc_list *pmc;
2069 	int	isexclude;
2070 	int	i, err;
2071 
2072 	if (!in_dev)
2073 		return -ENODEV;
2074 	rcu_read_lock();
2075 	for_each_pmc_rcu(in_dev, pmc) {
2076 		if (*pmca == pmc->multiaddr)
2077 			break;
2078 	}
2079 	if (!pmc) {
2080 		/* MCA not found?? bug */
2081 		rcu_read_unlock();
2082 		return -ESRCH;
2083 	}
2084 	spin_lock_bh(&pmc->lock);
2085 	rcu_read_unlock();
2086 
2087 #ifdef CONFIG_IP_MULTICAST
2088 	sf_markstate(pmc);
2089 #endif
2090 	isexclude = pmc->sfmode == MCAST_EXCLUDE;
2091 	if (!delta)
2092 		pmc->sfcount[sfmode]++;
2093 	err = 0;
2094 	for (i = 0; i < sfcount; i++) {
2095 		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2096 		if (err)
2097 			break;
2098 	}
2099 	if (err) {
2100 		int j;
2101 
2102 		if (!delta)
2103 			pmc->sfcount[sfmode]--;
2104 		for (j = 0; j < i; j++)
2105 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2106 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
2107 #ifdef CONFIG_IP_MULTICAST
2108 		struct ip_sf_list *psf;
2109 		struct net *net = dev_net(pmc->interface->dev);
2110 		in_dev = pmc->interface;
2111 #endif
2112 
2113 		/* filter mode change */
2114 		if (pmc->sfcount[MCAST_EXCLUDE])
2115 			pmc->sfmode = MCAST_EXCLUDE;
2116 		else if (pmc->sfcount[MCAST_INCLUDE])
2117 			pmc->sfmode = MCAST_INCLUDE;
2118 #ifdef CONFIG_IP_MULTICAST
2119 		/* else no filters; keep old mode for reports */
2120 
2121 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
2122 		in_dev->mr_ifc_count = pmc->crcount;
2123 		for (psf = pmc->sources; psf; psf = psf->sf_next)
2124 			psf->sf_crcount = 0;
2125 		igmp_ifc_event(in_dev);
2126 	} else if (sf_setstate(pmc)) {
2127 		igmp_ifc_event(in_dev);
2128 #endif
2129 	}
2130 	spin_unlock_bh(&pmc->lock);
2131 	return err;
2132 }
2133 
2134 static void ip_mc_clear_src(struct ip_mc_list *pmc)
2135 {
2136 	struct ip_sf_list *tomb, *sources;
2137 
2138 	spin_lock_bh(&pmc->lock);
2139 	tomb = pmc->tomb;
2140 	pmc->tomb = NULL;
2141 	sources = pmc->sources;
2142 	pmc->sources = NULL;
2143 	pmc->sfmode = MCAST_EXCLUDE;
2144 	pmc->sfcount[MCAST_INCLUDE] = 0;
2145 	pmc->sfcount[MCAST_EXCLUDE] = 1;
2146 	spin_unlock_bh(&pmc->lock);
2147 
2148 	ip_sf_list_clear_all(tomb);
2149 	ip_sf_list_clear_all(sources);
2150 }
2151 
2152 /* Join a multicast group
2153  */
2154 static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
2155 			      unsigned int mode)
2156 {
2157 	__be32 addr = imr->imr_multiaddr.s_addr;
2158 	struct ip_mc_socklist *iml, *i;
2159 	struct in_device *in_dev;
2160 	struct inet_sock *inet = inet_sk(sk);
2161 	struct net *net = sock_net(sk);
2162 	int ifindex;
2163 	int count = 0;
2164 	int err;
2165 
2166 	ASSERT_RTNL();
2167 
2168 	if (!ipv4_is_multicast(addr))
2169 		return -EINVAL;
2170 
2171 	in_dev = ip_mc_find_dev(net, imr);
2172 
2173 	if (!in_dev) {
2174 		err = -ENODEV;
2175 		goto done;
2176 	}
2177 
2178 	err = -EADDRINUSE;
2179 	ifindex = imr->imr_ifindex;
2180 	for_each_pmc_rtnl(inet, i) {
2181 		if (i->multi.imr_multiaddr.s_addr == addr &&
2182 		    i->multi.imr_ifindex == ifindex)
2183 			goto done;
2184 		count++;
2185 	}
2186 	err = -ENOBUFS;
2187 	if (count >= net->ipv4.sysctl_igmp_max_memberships)
2188 		goto done;
2189 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
2190 	if (!iml)
2191 		goto done;
2192 
2193 	memcpy(&iml->multi, imr, sizeof(*imr));
2194 	iml->next_rcu = inet->mc_list;
2195 	iml->sflist = NULL;
2196 	iml->sfmode = mode;
2197 	rcu_assign_pointer(inet->mc_list, iml);
2198 	____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL);
2199 	err = 0;
2200 done:
2201 	return err;
2202 }
2203 
2204 /* Join ASM (Any-Source Multicast) group
2205  */
2206 int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
2207 {
2208 	return __ip_mc_join_group(sk, imr, MCAST_EXCLUDE);
2209 }
2210 EXPORT_SYMBOL(ip_mc_join_group);
2211 
2212 /* Join SSM (Source-Specific Multicast) group
2213  */
2214 int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
2215 			 unsigned int mode)
2216 {
2217 	return __ip_mc_join_group(sk, imr, mode);
2218 }
2219 
2220 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
2221 			   struct in_device *in_dev)
2222 {
2223 	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
2224 	int err;
2225 
2226 	if (!psf) {
2227 		/* any-source empty exclude case */
2228 		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2229 			iml->sfmode, 0, NULL, 0);
2230 	}
2231 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2232 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
2233 	RCU_INIT_POINTER(iml->sflist, NULL);
2234 	/* decrease mem now to avoid the memleak warning */
2235 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
2236 	kfree_rcu(psf, rcu);
2237 	return err;
2238 }
2239 
2240 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
2241 {
2242 	struct inet_sock *inet = inet_sk(sk);
2243 	struct ip_mc_socklist *iml;
2244 	struct ip_mc_socklist __rcu **imlp;
2245 	struct in_device *in_dev;
2246 	struct net *net = sock_net(sk);
2247 	__be32 group = imr->imr_multiaddr.s_addr;
2248 	u32 ifindex;
2249 	int ret = -EADDRNOTAVAIL;
2250 
2251 	ASSERT_RTNL();
2252 
2253 	in_dev = ip_mc_find_dev(net, imr);
2254 	if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
2255 		ret = -ENODEV;
2256 		goto out;
2257 	}
2258 	ifindex = imr->imr_ifindex;
2259 	for (imlp = &inet->mc_list;
2260 	     (iml = rtnl_dereference(*imlp)) != NULL;
2261 	     imlp = &iml->next_rcu) {
2262 		if (iml->multi.imr_multiaddr.s_addr != group)
2263 			continue;
2264 		if (ifindex) {
2265 			if (iml->multi.imr_ifindex != ifindex)
2266 				continue;
2267 		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
2268 				iml->multi.imr_address.s_addr)
2269 			continue;
2270 
2271 		(void) ip_mc_leave_src(sk, iml, in_dev);
2272 
2273 		*imlp = iml->next_rcu;
2274 
2275 		if (in_dev)
2276 			ip_mc_dec_group(in_dev, group);
2277 
2278 		/* decrease mem now to avoid the memleak warning */
2279 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2280 		kfree_rcu(iml, rcu);
2281 		return 0;
2282 	}
2283 out:
2284 	return ret;
2285 }
2286 EXPORT_SYMBOL(ip_mc_leave_group);
2287 
2288 int ip_mc_source(int add, int omode, struct sock *sk, struct
2289 	ip_mreq_source *mreqs, int ifindex)
2290 {
2291 	int err;
2292 	struct ip_mreqn imr;
2293 	__be32 addr = mreqs->imr_multiaddr;
2294 	struct ip_mc_socklist *pmc;
2295 	struct in_device *in_dev = NULL;
2296 	struct inet_sock *inet = inet_sk(sk);
2297 	struct ip_sf_socklist *psl;
2298 	struct net *net = sock_net(sk);
2299 	int leavegroup = 0;
2300 	int i, j, rv;
2301 
2302 	if (!ipv4_is_multicast(addr))
2303 		return -EINVAL;
2304 
2305 	ASSERT_RTNL();
2306 
2307 	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
2308 	imr.imr_address.s_addr = mreqs->imr_interface;
2309 	imr.imr_ifindex = ifindex;
2310 	in_dev = ip_mc_find_dev(net, &imr);
2311 
2312 	if (!in_dev) {
2313 		err = -ENODEV;
2314 		goto done;
2315 	}
2316 	err = -EADDRNOTAVAIL;
2317 
2318 	for_each_pmc_rtnl(inet, pmc) {
2319 		if ((pmc->multi.imr_multiaddr.s_addr ==
2320 		     imr.imr_multiaddr.s_addr) &&
2321 		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
2322 			break;
2323 	}
2324 	if (!pmc) {		/* must have a prior join */
2325 		err = -EINVAL;
2326 		goto done;
2327 	}
2328 	/* if a source filter was set, must be the same mode as before */
2329 	if (pmc->sflist) {
2330 		if (pmc->sfmode != omode) {
2331 			err = -EINVAL;
2332 			goto done;
2333 		}
2334 	} else if (pmc->sfmode != omode) {
2335 		/* allow mode switches for empty-set filters */
2336 		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2337 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2338 			NULL, 0);
2339 		pmc->sfmode = omode;
2340 	}
2341 
2342 	psl = rtnl_dereference(pmc->sflist);
2343 	if (!add) {
2344 		if (!psl)
2345 			goto done;	/* err = -EADDRNOTAVAIL */
2346 		rv = !0;
2347 		for (i = 0; i < psl->sl_count; i++) {
2348 			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2349 				sizeof(__be32));
2350 			if (rv == 0)
2351 				break;
2352 		}
2353 		if (rv)		/* source not found */
2354 			goto done;	/* err = -EADDRNOTAVAIL */
2355 
2356 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2357 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2358 			leavegroup = 1;
2359 			goto done;
2360 		}
2361 
2362 		/* update the interface filter */
2363 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2364 			&mreqs->imr_sourceaddr, 1);
2365 
2366 		for (j = i+1; j < psl->sl_count; j++)
2367 			psl->sl_addr[j-1] = psl->sl_addr[j];
2368 		psl->sl_count--;
2369 		err = 0;
2370 		goto done;
2371 	}
2372 	/* else, add a new source to the filter */
2373 
2374 	if (psl && psl->sl_count >= net->ipv4.sysctl_igmp_max_msf) {
2375 		err = -ENOBUFS;
2376 		goto done;
2377 	}
2378 	if (!psl || psl->sl_count == psl->sl_max) {
2379 		struct ip_sf_socklist *newpsl;
2380 		int count = IP_SFBLOCK;
2381 
2382 		if (psl)
2383 			count += psl->sl_max;
2384 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2385 		if (!newpsl) {
2386 			err = -ENOBUFS;
2387 			goto done;
2388 		}
2389 		newpsl->sl_max = count;
2390 		newpsl->sl_count = count - IP_SFBLOCK;
2391 		if (psl) {
2392 			for (i = 0; i < psl->sl_count; i++)
2393 				newpsl->sl_addr[i] = psl->sl_addr[i];
2394 			/* decrease mem now to avoid the memleak warning */
2395 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2396 			kfree_rcu(psl, rcu);
2397 		}
2398 		rcu_assign_pointer(pmc->sflist, newpsl);
2399 		psl = newpsl;
2400 	}
2401 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
2402 	for (i = 0; i < psl->sl_count; i++) {
2403 		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2404 			sizeof(__be32));
2405 		if (rv == 0)
2406 			break;
2407 	}
2408 	if (rv == 0)		/* address already there is an error */
2409 		goto done;
2410 	for (j = psl->sl_count-1; j >= i; j--)
2411 		psl->sl_addr[j+1] = psl->sl_addr[j];
2412 	psl->sl_addr[i] = mreqs->imr_sourceaddr;
2413 	psl->sl_count++;
2414 	err = 0;
2415 	/* update the interface list */
2416 	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2417 		&mreqs->imr_sourceaddr, 1);
2418 done:
2419 	if (leavegroup)
2420 		err = ip_mc_leave_group(sk, &imr);
2421 	return err;
2422 }
2423 
2424 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2425 {
2426 	int err = 0;
2427 	struct ip_mreqn	imr;
2428 	__be32 addr = msf->imsf_multiaddr;
2429 	struct ip_mc_socklist *pmc;
2430 	struct in_device *in_dev;
2431 	struct inet_sock *inet = inet_sk(sk);
2432 	struct ip_sf_socklist *newpsl, *psl;
2433 	struct net *net = sock_net(sk);
2434 	int leavegroup = 0;
2435 
2436 	if (!ipv4_is_multicast(addr))
2437 		return -EINVAL;
2438 	if (msf->imsf_fmode != MCAST_INCLUDE &&
2439 	    msf->imsf_fmode != MCAST_EXCLUDE)
2440 		return -EINVAL;
2441 
2442 	ASSERT_RTNL();
2443 
2444 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2445 	imr.imr_address.s_addr = msf->imsf_interface;
2446 	imr.imr_ifindex = ifindex;
2447 	in_dev = ip_mc_find_dev(net, &imr);
2448 
2449 	if (!in_dev) {
2450 		err = -ENODEV;
2451 		goto done;
2452 	}
2453 
2454 	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2455 	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2456 		leavegroup = 1;
2457 		goto done;
2458 	}
2459 
2460 	for_each_pmc_rtnl(inet, pmc) {
2461 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2462 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2463 			break;
2464 	}
2465 	if (!pmc) {		/* must have a prior join */
2466 		err = -EINVAL;
2467 		goto done;
2468 	}
2469 	if (msf->imsf_numsrc) {
2470 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2471 							   GFP_KERNEL);
2472 		if (!newpsl) {
2473 			err = -ENOBUFS;
2474 			goto done;
2475 		}
2476 		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2477 		memcpy(newpsl->sl_addr, msf->imsf_slist,
2478 			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2479 		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2480 			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2481 		if (err) {
2482 			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2483 			goto done;
2484 		}
2485 	} else {
2486 		newpsl = NULL;
2487 		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2488 				     msf->imsf_fmode, 0, NULL, 0);
2489 	}
2490 	psl = rtnl_dereference(pmc->sflist);
2491 	if (psl) {
2492 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2493 			psl->sl_count, psl->sl_addr, 0);
2494 		/* decrease mem now to avoid the memleak warning */
2495 		atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2496 		kfree_rcu(psl, rcu);
2497 	} else
2498 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2499 			0, NULL, 0);
2500 	rcu_assign_pointer(pmc->sflist, newpsl);
2501 	pmc->sfmode = msf->imsf_fmode;
2502 	err = 0;
2503 done:
2504 	if (leavegroup)
2505 		err = ip_mc_leave_group(sk, &imr);
2506 	return err;
2507 }
2508 
2509 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2510 	struct ip_msfilter __user *optval, int __user *optlen)
2511 {
2512 	int err, len, count, copycount;
2513 	struct ip_mreqn	imr;
2514 	__be32 addr = msf->imsf_multiaddr;
2515 	struct ip_mc_socklist *pmc;
2516 	struct in_device *in_dev;
2517 	struct inet_sock *inet = inet_sk(sk);
2518 	struct ip_sf_socklist *psl;
2519 	struct net *net = sock_net(sk);
2520 
2521 	ASSERT_RTNL();
2522 
2523 	if (!ipv4_is_multicast(addr))
2524 		return -EINVAL;
2525 
2526 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2527 	imr.imr_address.s_addr = msf->imsf_interface;
2528 	imr.imr_ifindex = 0;
2529 	in_dev = ip_mc_find_dev(net, &imr);
2530 
2531 	if (!in_dev) {
2532 		err = -ENODEV;
2533 		goto done;
2534 	}
2535 	err = -EADDRNOTAVAIL;
2536 
2537 	for_each_pmc_rtnl(inet, pmc) {
2538 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2539 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2540 			break;
2541 	}
2542 	if (!pmc)		/* must have a prior join */
2543 		goto done;
2544 	msf->imsf_fmode = pmc->sfmode;
2545 	psl = rtnl_dereference(pmc->sflist);
2546 	if (!psl) {
2547 		len = 0;
2548 		count = 0;
2549 	} else {
2550 		count = psl->sl_count;
2551 	}
2552 	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2553 	len = copycount * sizeof(psl->sl_addr[0]);
2554 	msf->imsf_numsrc = count;
2555 	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2556 	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2557 		return -EFAULT;
2558 	}
2559 	if (len &&
2560 	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2561 		return -EFAULT;
2562 	return 0;
2563 done:
2564 	return err;
2565 }
2566 
2567 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2568 	struct sockaddr_storage __user *p)
2569 {
2570 	int i, count, copycount;
2571 	struct sockaddr_in *psin;
2572 	__be32 addr;
2573 	struct ip_mc_socklist *pmc;
2574 	struct inet_sock *inet = inet_sk(sk);
2575 	struct ip_sf_socklist *psl;
2576 
2577 	ASSERT_RTNL();
2578 
2579 	psin = (struct sockaddr_in *)&gsf->gf_group;
2580 	if (psin->sin_family != AF_INET)
2581 		return -EINVAL;
2582 	addr = psin->sin_addr.s_addr;
2583 	if (!ipv4_is_multicast(addr))
2584 		return -EINVAL;
2585 
2586 	for_each_pmc_rtnl(inet, pmc) {
2587 		if (pmc->multi.imr_multiaddr.s_addr == addr &&
2588 		    pmc->multi.imr_ifindex == gsf->gf_interface)
2589 			break;
2590 	}
2591 	if (!pmc)		/* must have a prior join */
2592 		return -EADDRNOTAVAIL;
2593 	gsf->gf_fmode = pmc->sfmode;
2594 	psl = rtnl_dereference(pmc->sflist);
2595 	count = psl ? psl->sl_count : 0;
2596 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2597 	gsf->gf_numsrc = count;
2598 	for (i = 0; i < copycount; i++, p++) {
2599 		struct sockaddr_storage ss;
2600 
2601 		psin = (struct sockaddr_in *)&ss;
2602 		memset(&ss, 0, sizeof(ss));
2603 		psin->sin_family = AF_INET;
2604 		psin->sin_addr.s_addr = psl->sl_addr[i];
2605 		if (copy_to_user(p, &ss, sizeof(ss)))
2606 			return -EFAULT;
2607 	}
2608 	return 0;
2609 }
2610 
2611 /*
2612  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2613  */
2614 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
2615 		   int dif, int sdif)
2616 {
2617 	struct inet_sock *inet = inet_sk(sk);
2618 	struct ip_mc_socklist *pmc;
2619 	struct ip_sf_socklist *psl;
2620 	int i;
2621 	int ret;
2622 
2623 	ret = 1;
2624 	if (!ipv4_is_multicast(loc_addr))
2625 		goto out;
2626 
2627 	rcu_read_lock();
2628 	for_each_pmc_rcu(inet, pmc) {
2629 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2630 		    (pmc->multi.imr_ifindex == dif ||
2631 		     (sdif && pmc->multi.imr_ifindex == sdif)))
2632 			break;
2633 	}
2634 	ret = inet->mc_all;
2635 	if (!pmc)
2636 		goto unlock;
2637 	psl = rcu_dereference(pmc->sflist);
2638 	ret = (pmc->sfmode == MCAST_EXCLUDE);
2639 	if (!psl)
2640 		goto unlock;
2641 
2642 	for (i = 0; i < psl->sl_count; i++) {
2643 		if (psl->sl_addr[i] == rmt_addr)
2644 			break;
2645 	}
2646 	ret = 0;
2647 	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2648 		goto unlock;
2649 	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2650 		goto unlock;
2651 	ret = 1;
2652 unlock:
2653 	rcu_read_unlock();
2654 out:
2655 	return ret;
2656 }
2657 
2658 /*
2659  *	A socket is closing.
2660  */
2661 
2662 void ip_mc_drop_socket(struct sock *sk)
2663 {
2664 	struct inet_sock *inet = inet_sk(sk);
2665 	struct ip_mc_socklist *iml;
2666 	struct net *net = sock_net(sk);
2667 
2668 	if (!inet->mc_list)
2669 		return;
2670 
2671 	rtnl_lock();
2672 	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2673 		struct in_device *in_dev;
2674 
2675 		inet->mc_list = iml->next_rcu;
2676 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2677 		(void) ip_mc_leave_src(sk, iml, in_dev);
2678 		if (in_dev)
2679 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2680 		/* decrease mem now to avoid the memleak warning */
2681 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2682 		kfree_rcu(iml, rcu);
2683 	}
2684 	rtnl_unlock();
2685 }
2686 
2687 /* called with rcu_read_lock() */
2688 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
2689 {
2690 	struct ip_mc_list *im;
2691 	struct ip_mc_list __rcu **mc_hash;
2692 	struct ip_sf_list *psf;
2693 	int rv = 0;
2694 
2695 	mc_hash = rcu_dereference(in_dev->mc_hash);
2696 	if (mc_hash) {
2697 		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2698 
2699 		for (im = rcu_dereference(mc_hash[hash]);
2700 		     im != NULL;
2701 		     im = rcu_dereference(im->next_hash)) {
2702 			if (im->multiaddr == mc_addr)
2703 				break;
2704 		}
2705 	} else {
2706 		for_each_pmc_rcu(in_dev, im) {
2707 			if (im->multiaddr == mc_addr)
2708 				break;
2709 		}
2710 	}
2711 	if (im && proto == IPPROTO_IGMP) {
2712 		rv = 1;
2713 	} else if (im) {
2714 		if (src_addr) {
2715 			for (psf = im->sources; psf; psf = psf->sf_next) {
2716 				if (psf->sf_inaddr == src_addr)
2717 					break;
2718 			}
2719 			if (psf)
2720 				rv = psf->sf_count[MCAST_INCLUDE] ||
2721 					psf->sf_count[MCAST_EXCLUDE] !=
2722 					im->sfcount[MCAST_EXCLUDE];
2723 			else
2724 				rv = im->sfcount[MCAST_EXCLUDE] != 0;
2725 		} else
2726 			rv = 1; /* unspecified source; tentatively allow */
2727 	}
2728 	return rv;
2729 }
2730 
2731 #if defined(CONFIG_PROC_FS)
2732 struct igmp_mc_iter_state {
2733 	struct seq_net_private p;
2734 	struct net_device *dev;
2735 	struct in_device *in_dev;
2736 };
2737 
2738 #define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
2739 
2740 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2741 {
2742 	struct net *net = seq_file_net(seq);
2743 	struct ip_mc_list *im = NULL;
2744 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2745 
2746 	state->in_dev = NULL;
2747 	for_each_netdev_rcu(net, state->dev) {
2748 		struct in_device *in_dev;
2749 
2750 		in_dev = __in_dev_get_rcu(state->dev);
2751 		if (!in_dev)
2752 			continue;
2753 		im = rcu_dereference(in_dev->mc_list);
2754 		if (im) {
2755 			state->in_dev = in_dev;
2756 			break;
2757 		}
2758 	}
2759 	return im;
2760 }
2761 
2762 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2763 {
2764 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2765 
2766 	im = rcu_dereference(im->next_rcu);
2767 	while (!im) {
2768 		state->dev = next_net_device_rcu(state->dev);
2769 		if (!state->dev) {
2770 			state->in_dev = NULL;
2771 			break;
2772 		}
2773 		state->in_dev = __in_dev_get_rcu(state->dev);
2774 		if (!state->in_dev)
2775 			continue;
2776 		im = rcu_dereference(state->in_dev->mc_list);
2777 	}
2778 	return im;
2779 }
2780 
2781 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2782 {
2783 	struct ip_mc_list *im = igmp_mc_get_first(seq);
2784 	if (im)
2785 		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2786 			--pos;
2787 	return pos ? NULL : im;
2788 }
2789 
2790 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2791 	__acquires(rcu)
2792 {
2793 	rcu_read_lock();
2794 	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2795 }
2796 
2797 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2798 {
2799 	struct ip_mc_list *im;
2800 	if (v == SEQ_START_TOKEN)
2801 		im = igmp_mc_get_first(seq);
2802 	else
2803 		im = igmp_mc_get_next(seq, v);
2804 	++*pos;
2805 	return im;
2806 }
2807 
2808 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2809 	__releases(rcu)
2810 {
2811 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2812 
2813 	state->in_dev = NULL;
2814 	state->dev = NULL;
2815 	rcu_read_unlock();
2816 }
2817 
2818 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2819 {
2820 	if (v == SEQ_START_TOKEN)
2821 		seq_puts(seq,
2822 			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2823 	else {
2824 		struct ip_mc_list *im = (struct ip_mc_list *)v;
2825 		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2826 		char   *querier;
2827 		long delta;
2828 
2829 #ifdef CONFIG_IP_MULTICAST
2830 		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2831 			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
2832 			  "V3";
2833 #else
2834 		querier = "NONE";
2835 #endif
2836 
2837 		if (rcu_access_pointer(state->in_dev->mc_list) == im) {
2838 			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2839 				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2840 		}
2841 
2842 		delta = im->timer.expires - jiffies;
2843 		seq_printf(seq,
2844 			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2845 			   im->multiaddr, im->users,
2846 			   im->tm_running,
2847 			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2848 			   im->reporter);
2849 	}
2850 	return 0;
2851 }
2852 
2853 static const struct seq_operations igmp_mc_seq_ops = {
2854 	.start	=	igmp_mc_seq_start,
2855 	.next	=	igmp_mc_seq_next,
2856 	.stop	=	igmp_mc_seq_stop,
2857 	.show	=	igmp_mc_seq_show,
2858 };
2859 
2860 struct igmp_mcf_iter_state {
2861 	struct seq_net_private p;
2862 	struct net_device *dev;
2863 	struct in_device *idev;
2864 	struct ip_mc_list *im;
2865 };
2866 
2867 #define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
2868 
2869 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2870 {
2871 	struct net *net = seq_file_net(seq);
2872 	struct ip_sf_list *psf = NULL;
2873 	struct ip_mc_list *im = NULL;
2874 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2875 
2876 	state->idev = NULL;
2877 	state->im = NULL;
2878 	for_each_netdev_rcu(net, state->dev) {
2879 		struct in_device *idev;
2880 		idev = __in_dev_get_rcu(state->dev);
2881 		if (unlikely(!idev))
2882 			continue;
2883 		im = rcu_dereference(idev->mc_list);
2884 		if (likely(im)) {
2885 			spin_lock_bh(&im->lock);
2886 			psf = im->sources;
2887 			if (likely(psf)) {
2888 				state->im = im;
2889 				state->idev = idev;
2890 				break;
2891 			}
2892 			spin_unlock_bh(&im->lock);
2893 		}
2894 	}
2895 	return psf;
2896 }
2897 
2898 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2899 {
2900 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2901 
2902 	psf = psf->sf_next;
2903 	while (!psf) {
2904 		spin_unlock_bh(&state->im->lock);
2905 		state->im = state->im->next;
2906 		while (!state->im) {
2907 			state->dev = next_net_device_rcu(state->dev);
2908 			if (!state->dev) {
2909 				state->idev = NULL;
2910 				goto out;
2911 			}
2912 			state->idev = __in_dev_get_rcu(state->dev);
2913 			if (!state->idev)
2914 				continue;
2915 			state->im = rcu_dereference(state->idev->mc_list);
2916 		}
2917 		if (!state->im)
2918 			break;
2919 		spin_lock_bh(&state->im->lock);
2920 		psf = state->im->sources;
2921 	}
2922 out:
2923 	return psf;
2924 }
2925 
2926 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2927 {
2928 	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2929 	if (psf)
2930 		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2931 			--pos;
2932 	return pos ? NULL : psf;
2933 }
2934 
2935 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2936 	__acquires(rcu)
2937 {
2938 	rcu_read_lock();
2939 	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2940 }
2941 
2942 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2943 {
2944 	struct ip_sf_list *psf;
2945 	if (v == SEQ_START_TOKEN)
2946 		psf = igmp_mcf_get_first(seq);
2947 	else
2948 		psf = igmp_mcf_get_next(seq, v);
2949 	++*pos;
2950 	return psf;
2951 }
2952 
2953 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2954 	__releases(rcu)
2955 {
2956 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2957 	if (likely(state->im)) {
2958 		spin_unlock_bh(&state->im->lock);
2959 		state->im = NULL;
2960 	}
2961 	state->idev = NULL;
2962 	state->dev = NULL;
2963 	rcu_read_unlock();
2964 }
2965 
2966 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2967 {
2968 	struct ip_sf_list *psf = (struct ip_sf_list *)v;
2969 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2970 
2971 	if (v == SEQ_START_TOKEN) {
2972 		seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
2973 	} else {
2974 		seq_printf(seq,
2975 			   "%3d %6.6s 0x%08x "
2976 			   "0x%08x %6lu %6lu\n",
2977 			   state->dev->ifindex, state->dev->name,
2978 			   ntohl(state->im->multiaddr),
2979 			   ntohl(psf->sf_inaddr),
2980 			   psf->sf_count[MCAST_INCLUDE],
2981 			   psf->sf_count[MCAST_EXCLUDE]);
2982 	}
2983 	return 0;
2984 }
2985 
2986 static const struct seq_operations igmp_mcf_seq_ops = {
2987 	.start	=	igmp_mcf_seq_start,
2988 	.next	=	igmp_mcf_seq_next,
2989 	.stop	=	igmp_mcf_seq_stop,
2990 	.show	=	igmp_mcf_seq_show,
2991 };
2992 
2993 static int __net_init igmp_net_init(struct net *net)
2994 {
2995 	struct proc_dir_entry *pde;
2996 	int err;
2997 
2998 	pde = proc_create_net("igmp", 0444, net->proc_net, &igmp_mc_seq_ops,
2999 			sizeof(struct igmp_mc_iter_state));
3000 	if (!pde)
3001 		goto out_igmp;
3002 	pde = proc_create_net("mcfilter", 0444, net->proc_net,
3003 			&igmp_mcf_seq_ops, sizeof(struct igmp_mcf_iter_state));
3004 	if (!pde)
3005 		goto out_mcfilter;
3006 	err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
3007 				   SOCK_DGRAM, 0, net);
3008 	if (err < 0) {
3009 		pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
3010 		       err);
3011 		goto out_sock;
3012 	}
3013 
3014 	return 0;
3015 
3016 out_sock:
3017 	remove_proc_entry("mcfilter", net->proc_net);
3018 out_mcfilter:
3019 	remove_proc_entry("igmp", net->proc_net);
3020 out_igmp:
3021 	return -ENOMEM;
3022 }
3023 
3024 static void __net_exit igmp_net_exit(struct net *net)
3025 {
3026 	remove_proc_entry("mcfilter", net->proc_net);
3027 	remove_proc_entry("igmp", net->proc_net);
3028 	inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
3029 }
3030 
3031 static struct pernet_operations igmp_net_ops = {
3032 	.init = igmp_net_init,
3033 	.exit = igmp_net_exit,
3034 };
3035 #endif
3036 
3037 static int igmp_netdev_event(struct notifier_block *this,
3038 			     unsigned long event, void *ptr)
3039 {
3040 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3041 	struct in_device *in_dev;
3042 
3043 	switch (event) {
3044 	case NETDEV_RESEND_IGMP:
3045 		in_dev = __in_dev_get_rtnl(dev);
3046 		if (in_dev)
3047 			ip_mc_rejoin_groups(in_dev);
3048 		break;
3049 	default:
3050 		break;
3051 	}
3052 	return NOTIFY_DONE;
3053 }
3054 
3055 static struct notifier_block igmp_notifier = {
3056 	.notifier_call = igmp_netdev_event,
3057 };
3058 
3059 int __init igmp_mc_init(void)
3060 {
3061 #if defined(CONFIG_PROC_FS)
3062 	int err;
3063 
3064 	err = register_pernet_subsys(&igmp_net_ops);
3065 	if (err)
3066 		return err;
3067 	err = register_netdevice_notifier(&igmp_notifier);
3068 	if (err)
3069 		goto reg_notif_fail;
3070 	return 0;
3071 
3072 reg_notif_fail:
3073 	unregister_pernet_subsys(&igmp_net_ops);
3074 	return err;
3075 #else
3076 	return register_netdevice_notifier(&igmp_notifier);
3077 #endif
3078 }
3079