xref: /openbmc/linux/net/ipv4/igmp.c (revision 020c5260)
1 /*
2  *	Linux NET3:	Internet Group Management Protocol  [IGMP]
3  *
4  *	This code implements the IGMP protocol as defined in RFC1112. There has
5  *	been a further revision of this protocol since which is now supported.
6  *
7  *	If you have trouble with this module be careful what gcc you have used,
8  *	the older version didn't come out right using gcc 2.5.8, the newer one
9  *	seems to fall out with gcc 2.6.2.
10  *
11  *	Authors:
12  *		Alan Cox <alan@lxorguk.ukuu.org.uk>
13  *
14  *	This program is free software; you can redistribute it and/or
15  *	modify it under the terms of the GNU General Public License
16  *	as published by the Free Software Foundation; either version
17  *	2 of the License, or (at your option) any later version.
18  *
19  *	Fixes:
20  *
21  *		Alan Cox	:	Added lots of __inline__ to optimise
22  *					the memory usage of all the tiny little
23  *					functions.
24  *		Alan Cox	:	Dumped the header building experiment.
25  *		Alan Cox	:	Minor tweaks ready for multicast routing
26  *					and extended IGMP protocol.
27  *		Alan Cox	:	Removed a load of inline directives. Gcc 2.5.8
28  *					writes utterly bogus code otherwise (sigh)
29  *					fixed IGMP loopback to behave in the manner
30  *					desired by mrouted, fixed the fact it has been
31  *					broken since 1.3.6 and cleaned up a few minor
32  *					points.
33  *
34  *		Chih-Jen Chang	:	Tried to revise IGMP to Version 2
35  *		Tsu-Sheng Tsao		E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
36  *					The enhancements are mainly based on Steve Deering's
37  * 					ipmulti-3.5 source code.
38  *		Chih-Jen Chang	:	Added the igmp_get_mrouter_info and
39  *		Tsu-Sheng Tsao		igmp_set_mrouter_info to keep track of
40  *					the mrouted version on that device.
41  *		Chih-Jen Chang	:	Added the max_resp_time parameter to
42  *		Tsu-Sheng Tsao		igmp_heard_query(). Using this parameter
43  *					to identify the multicast router version
44  *					and do what the IGMP version 2 specified.
45  *		Chih-Jen Chang	:	Added a timer to revert to IGMP V2 router
46  *		Tsu-Sheng Tsao		if the specified time expired.
47  *		Alan Cox	:	Stop IGMP from 0.0.0.0 being accepted.
48  *		Alan Cox	:	Use GFP_ATOMIC in the right places.
49  *		Christian Daudt :	igmp timer wasn't set for local group
50  *					memberships but was being deleted,
51  *					which caused a "del_timer() called
52  *					from %p with timer not initialized\n"
53  *					message (960131).
54  *		Christian Daudt :	removed del_timer from
55  *					igmp_timer_expire function (960205).
56  *             Christian Daudt :       igmp_heard_report now only calls
57  *                                     igmp_timer_expire if tm->running is
58  *                                     true (960216).
59  *		Malcolm Beattie :	ttl comparison wrong in igmp_rcv made
60  *					igmp_heard_query never trigger. Expiry
61  *					miscalculation fixed in igmp_heard_query
62  *					and random() made to return unsigned to
63  *					prevent negative expiry times.
64  *		Alexey Kuznetsov:	Wrong group leaving behaviour, backport
65  *					fix from pending 2.1.x patches.
66  *		Alan Cox:		Forget to enable FDDI support earlier.
67  *		Alexey Kuznetsov:	Fixed leaving groups on device down.
68  *		Alexey Kuznetsov:	Accordance to igmp-v2-06 draft.
69  *		David L Stevens:	IGMPv3 support, with help from
70  *					Vinay Kulkarni
71  */
72 
73 #include <linux/module.h>
74 #include <linux/slab.h>
75 #include <linux/uaccess.h>
76 #include <linux/types.h>
77 #include <linux/kernel.h>
78 #include <linux/jiffies.h>
79 #include <linux/string.h>
80 #include <linux/socket.h>
81 #include <linux/sockios.h>
82 #include <linux/in.h>
83 #include <linux/inet.h>
84 #include <linux/netdevice.h>
85 #include <linux/skbuff.h>
86 #include <linux/inetdevice.h>
87 #include <linux/igmp.h>
88 #include <linux/if_arp.h>
89 #include <linux/rtnetlink.h>
90 #include <linux/times.h>
91 #include <linux/pkt_sched.h>
92 
93 #include <net/net_namespace.h>
94 #include <net/arp.h>
95 #include <net/ip.h>
96 #include <net/protocol.h>
97 #include <net/route.h>
98 #include <net/sock.h>
99 #include <net/checksum.h>
100 #include <net/inet_common.h>
101 #include <linux/netfilter_ipv4.h>
102 #ifdef CONFIG_IP_MROUTE
103 #include <linux/mroute.h>
104 #endif
105 #ifdef CONFIG_PROC_FS
106 #include <linux/proc_fs.h>
107 #include <linux/seq_file.h>
108 #endif
109 
110 #ifdef CONFIG_IP_MULTICAST
111 /* Parameter names and values are taken from igmp-v2-06 draft */
112 
113 #define IGMP_V1_ROUTER_PRESENT_TIMEOUT		(400*HZ)
114 #define IGMP_V2_ROUTER_PRESENT_TIMEOUT		(400*HZ)
115 #define IGMP_V2_UNSOLICITED_REPORT_INTERVAL	(10*HZ)
116 #define IGMP_V3_UNSOLICITED_REPORT_INTERVAL	(1*HZ)
117 #define IGMP_QUERY_RESPONSE_INTERVAL		(10*HZ)
118 #define IGMP_QUERY_ROBUSTNESS_VARIABLE		2
119 
120 
121 #define IGMP_INITIAL_REPORT_DELAY		(1)
122 
123 /* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
124  * IGMP specs require to report membership immediately after
125  * joining a group, but we delay the first report by a
126  * small interval. It seems more natural and still does not
127  * contradict to specs provided this delay is small enough.
128  */
129 
130 #define IGMP_V1_SEEN(in_dev) \
131 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
132 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
133 	 ((in_dev)->mr_v1_seen && \
134 	  time_before(jiffies, (in_dev)->mr_v1_seen)))
135 #define IGMP_V2_SEEN(in_dev) \
136 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
137 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
138 	 ((in_dev)->mr_v2_seen && \
139 	  time_before(jiffies, (in_dev)->mr_v2_seen)))
140 
141 static int unsolicited_report_interval(struct in_device *in_dev)
142 {
143 	int interval_ms, interval_jiffies;
144 
145 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
146 		interval_ms = IN_DEV_CONF_GET(
147 			in_dev,
148 			IGMPV2_UNSOLICITED_REPORT_INTERVAL);
149 	else /* v3 */
150 		interval_ms = IN_DEV_CONF_GET(
151 			in_dev,
152 			IGMPV3_UNSOLICITED_REPORT_INTERVAL);
153 
154 	interval_jiffies = msecs_to_jiffies(interval_ms);
155 
156 	/* _timer functions can't handle a delay of 0 jiffies so ensure
157 	 *  we always return a positive value.
158 	 */
159 	if (interval_jiffies <= 0)
160 		interval_jiffies = 1;
161 	return interval_jiffies;
162 }
163 
164 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
165 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im);
166 static void igmpv3_clear_delrec(struct in_device *in_dev);
167 static int sf_setstate(struct ip_mc_list *pmc);
168 static void sf_markstate(struct ip_mc_list *pmc);
169 #endif
170 static void ip_mc_clear_src(struct ip_mc_list *pmc);
171 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
172 			 int sfcount, __be32 *psfsrc, int delta);
173 
174 static void ip_ma_put(struct ip_mc_list *im)
175 {
176 	if (atomic_dec_and_test(&im->refcnt)) {
177 		in_dev_put(im->interface);
178 		kfree_rcu(im, rcu);
179 	}
180 }
181 
182 #define for_each_pmc_rcu(in_dev, pmc)				\
183 	for (pmc = rcu_dereference(in_dev->mc_list);		\
184 	     pmc != NULL;					\
185 	     pmc = rcu_dereference(pmc->next_rcu))
186 
187 #define for_each_pmc_rtnl(in_dev, pmc)				\
188 	for (pmc = rtnl_dereference(in_dev->mc_list);		\
189 	     pmc != NULL;					\
190 	     pmc = rtnl_dereference(pmc->next_rcu))
191 
192 #ifdef CONFIG_IP_MULTICAST
193 
194 /*
195  *	Timer management
196  */
197 
198 static void igmp_stop_timer(struct ip_mc_list *im)
199 {
200 	spin_lock_bh(&im->lock);
201 	if (del_timer(&im->timer))
202 		atomic_dec(&im->refcnt);
203 	im->tm_running = 0;
204 	im->reporter = 0;
205 	im->unsolicit_count = 0;
206 	spin_unlock_bh(&im->lock);
207 }
208 
209 /* It must be called with locked im->lock */
210 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
211 {
212 	int tv = prandom_u32() % max_delay;
213 
214 	im->tm_running = 1;
215 	if (!mod_timer(&im->timer, jiffies+tv+2))
216 		atomic_inc(&im->refcnt);
217 }
218 
219 static void igmp_gq_start_timer(struct in_device *in_dev)
220 {
221 	int tv = prandom_u32() % in_dev->mr_maxdelay;
222 	unsigned long exp = jiffies + tv + 2;
223 
224 	if (in_dev->mr_gq_running &&
225 	    time_after_eq(exp, (in_dev->mr_gq_timer).expires))
226 		return;
227 
228 	in_dev->mr_gq_running = 1;
229 	if (!mod_timer(&in_dev->mr_gq_timer, exp))
230 		in_dev_hold(in_dev);
231 }
232 
233 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
234 {
235 	int tv = prandom_u32() % delay;
236 
237 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
238 		in_dev_hold(in_dev);
239 }
240 
241 static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
242 {
243 	spin_lock_bh(&im->lock);
244 	im->unsolicit_count = 0;
245 	if (del_timer(&im->timer)) {
246 		if ((long)(im->timer.expires-jiffies) < max_delay) {
247 			add_timer(&im->timer);
248 			im->tm_running = 1;
249 			spin_unlock_bh(&im->lock);
250 			return;
251 		}
252 		atomic_dec(&im->refcnt);
253 	}
254 	igmp_start_timer(im, max_delay);
255 	spin_unlock_bh(&im->lock);
256 }
257 
258 
259 /*
260  *	Send an IGMP report.
261  */
262 
263 #define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
264 
265 
266 static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
267 	int gdeleted, int sdeleted)
268 {
269 	switch (type) {
270 	case IGMPV3_MODE_IS_INCLUDE:
271 	case IGMPV3_MODE_IS_EXCLUDE:
272 		if (gdeleted || sdeleted)
273 			return 0;
274 		if (!(pmc->gsquery && !psf->sf_gsresp)) {
275 			if (pmc->sfmode == MCAST_INCLUDE)
276 				return 1;
277 			/* don't include if this source is excluded
278 			 * in all filters
279 			 */
280 			if (psf->sf_count[MCAST_INCLUDE])
281 				return type == IGMPV3_MODE_IS_INCLUDE;
282 			return pmc->sfcount[MCAST_EXCLUDE] ==
283 				psf->sf_count[MCAST_EXCLUDE];
284 		}
285 		return 0;
286 	case IGMPV3_CHANGE_TO_INCLUDE:
287 		if (gdeleted || sdeleted)
288 			return 0;
289 		return psf->sf_count[MCAST_INCLUDE] != 0;
290 	case IGMPV3_CHANGE_TO_EXCLUDE:
291 		if (gdeleted || sdeleted)
292 			return 0;
293 		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
294 		    psf->sf_count[MCAST_INCLUDE])
295 			return 0;
296 		return pmc->sfcount[MCAST_EXCLUDE] ==
297 			psf->sf_count[MCAST_EXCLUDE];
298 	case IGMPV3_ALLOW_NEW_SOURCES:
299 		if (gdeleted || !psf->sf_crcount)
300 			return 0;
301 		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
302 	case IGMPV3_BLOCK_OLD_SOURCES:
303 		if (pmc->sfmode == MCAST_INCLUDE)
304 			return gdeleted || (psf->sf_crcount && sdeleted);
305 		return psf->sf_crcount && !gdeleted && !sdeleted;
306 	}
307 	return 0;
308 }
309 
310 static int
311 igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
312 {
313 	struct ip_sf_list *psf;
314 	int scount = 0;
315 
316 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
317 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
318 			continue;
319 		scount++;
320 	}
321 	return scount;
322 }
323 
324 static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
325 {
326 	struct sk_buff *skb;
327 	struct rtable *rt;
328 	struct iphdr *pip;
329 	struct igmpv3_report *pig;
330 	struct net *net = dev_net(dev);
331 	struct flowi4 fl4;
332 	int hlen = LL_RESERVED_SPACE(dev);
333 	int tlen = dev->needed_tailroom;
334 	unsigned int size = mtu;
335 
336 	while (1) {
337 		skb = alloc_skb(size + hlen + tlen,
338 				GFP_ATOMIC | __GFP_NOWARN);
339 		if (skb)
340 			break;
341 		size >>= 1;
342 		if (size < 256)
343 			return NULL;
344 	}
345 	skb->priority = TC_PRIO_CONTROL;
346 
347 	rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
348 				   0, 0,
349 				   IPPROTO_IGMP, 0, dev->ifindex);
350 	if (IS_ERR(rt)) {
351 		kfree_skb(skb);
352 		return NULL;
353 	}
354 
355 	skb_dst_set(skb, &rt->dst);
356 	skb->dev = dev;
357 
358 	skb_reserve(skb, hlen);
359 	skb_tailroom_reserve(skb, mtu, tlen);
360 
361 	skb_reset_network_header(skb);
362 	pip = ip_hdr(skb);
363 	skb_put(skb, sizeof(struct iphdr) + 4);
364 
365 	pip->version  = 4;
366 	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
367 	pip->tos      = 0xc0;
368 	pip->frag_off = htons(IP_DF);
369 	pip->ttl      = 1;
370 	pip->daddr    = fl4.daddr;
371 	pip->saddr    = fl4.saddr;
372 	pip->protocol = IPPROTO_IGMP;
373 	pip->tot_len  = 0;	/* filled in later */
374 	ip_select_ident(net, skb, NULL);
375 	((u8 *)&pip[1])[0] = IPOPT_RA;
376 	((u8 *)&pip[1])[1] = 4;
377 	((u8 *)&pip[1])[2] = 0;
378 	((u8 *)&pip[1])[3] = 0;
379 
380 	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
381 	skb_put(skb, sizeof(*pig));
382 	pig = igmpv3_report_hdr(skb);
383 	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
384 	pig->resv1 = 0;
385 	pig->csum = 0;
386 	pig->resv2 = 0;
387 	pig->ngrec = 0;
388 	return skb;
389 }
390 
391 static int igmpv3_sendpack(struct sk_buff *skb)
392 {
393 	struct igmphdr *pig = igmp_hdr(skb);
394 	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
395 
396 	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
397 
398 	return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
399 }
400 
401 static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
402 {
403 	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
404 }
405 
406 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
407 	int type, struct igmpv3_grec **ppgr)
408 {
409 	struct net_device *dev = pmc->interface->dev;
410 	struct igmpv3_report *pih;
411 	struct igmpv3_grec *pgr;
412 
413 	if (!skb)
414 		skb = igmpv3_newpack(dev, dev->mtu);
415 	if (!skb)
416 		return NULL;
417 	pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
418 	pgr->grec_type = type;
419 	pgr->grec_auxwords = 0;
420 	pgr->grec_nsrcs = 0;
421 	pgr->grec_mca = pmc->multiaddr;
422 	pih = igmpv3_report_hdr(skb);
423 	pih->ngrec = htons(ntohs(pih->ngrec)+1);
424 	*ppgr = pgr;
425 	return skb;
426 }
427 
428 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
429 
430 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
431 	int type, int gdeleted, int sdeleted)
432 {
433 	struct net_device *dev = pmc->interface->dev;
434 	struct net *net = dev_net(dev);
435 	struct igmpv3_report *pih;
436 	struct igmpv3_grec *pgr = NULL;
437 	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
438 	int scount, stotal, first, isquery, truncate;
439 
440 	if (pmc->multiaddr == IGMP_ALL_HOSTS)
441 		return skb;
442 	if (ipv4_is_local_multicast(pmc->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
443 		return skb;
444 
445 	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
446 		  type == IGMPV3_MODE_IS_EXCLUDE;
447 	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
448 		    type == IGMPV3_CHANGE_TO_EXCLUDE;
449 
450 	stotal = scount = 0;
451 
452 	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
453 
454 	if (!*psf_list)
455 		goto empty_source;
456 
457 	pih = skb ? igmpv3_report_hdr(skb) : NULL;
458 
459 	/* EX and TO_EX get a fresh packet, if needed */
460 	if (truncate) {
461 		if (pih && pih->ngrec &&
462 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
463 			if (skb)
464 				igmpv3_sendpack(skb);
465 			skb = igmpv3_newpack(dev, dev->mtu);
466 		}
467 	}
468 	first = 1;
469 	psf_prev = NULL;
470 	for (psf = *psf_list; psf; psf = psf_next) {
471 		__be32 *psrc;
472 
473 		psf_next = psf->sf_next;
474 
475 		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
476 			psf_prev = psf;
477 			continue;
478 		}
479 
480 		/* Based on RFC3376 5.1. Should not send source-list change
481 		 * records when there is a filter mode change.
482 		 */
483 		if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) ||
484 		     (!gdeleted && pmc->crcount)) &&
485 		    (type == IGMPV3_ALLOW_NEW_SOURCES ||
486 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount)
487 			goto decrease_sf_crcount;
488 
489 		/* clear marks on query responses */
490 		if (isquery)
491 			psf->sf_gsresp = 0;
492 
493 		if (AVAILABLE(skb) < sizeof(__be32) +
494 		    first*sizeof(struct igmpv3_grec)) {
495 			if (truncate && !first)
496 				break;	 /* truncate these */
497 			if (pgr)
498 				pgr->grec_nsrcs = htons(scount);
499 			if (skb)
500 				igmpv3_sendpack(skb);
501 			skb = igmpv3_newpack(dev, dev->mtu);
502 			first = 1;
503 			scount = 0;
504 		}
505 		if (first) {
506 			skb = add_grhead(skb, pmc, type, &pgr);
507 			first = 0;
508 		}
509 		if (!skb)
510 			return NULL;
511 		psrc = (__be32 *)skb_put(skb, sizeof(__be32));
512 		*psrc = psf->sf_inaddr;
513 		scount++; stotal++;
514 		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
515 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
516 decrease_sf_crcount:
517 			psf->sf_crcount--;
518 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
519 				if (psf_prev)
520 					psf_prev->sf_next = psf->sf_next;
521 				else
522 					*psf_list = psf->sf_next;
523 				kfree(psf);
524 				continue;
525 			}
526 		}
527 		psf_prev = psf;
528 	}
529 
530 empty_source:
531 	if (!stotal) {
532 		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
533 		    type == IGMPV3_BLOCK_OLD_SOURCES)
534 			return skb;
535 		if (pmc->crcount || isquery) {
536 			/* make sure we have room for group header */
537 			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
538 				igmpv3_sendpack(skb);
539 				skb = NULL; /* add_grhead will get a new one */
540 			}
541 			skb = add_grhead(skb, pmc, type, &pgr);
542 		}
543 	}
544 	if (pgr)
545 		pgr->grec_nsrcs = htons(scount);
546 
547 	if (isquery)
548 		pmc->gsquery = 0;	/* clear query state on report */
549 	return skb;
550 }
551 
552 static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
553 {
554 	struct sk_buff *skb = NULL;
555 	struct net *net = dev_net(in_dev->dev);
556 	int type;
557 
558 	if (!pmc) {
559 		rcu_read_lock();
560 		for_each_pmc_rcu(in_dev, pmc) {
561 			if (pmc->multiaddr == IGMP_ALL_HOSTS)
562 				continue;
563 			if (ipv4_is_local_multicast(pmc->multiaddr) &&
564 			     !net->ipv4.sysctl_igmp_llm_reports)
565 				continue;
566 			spin_lock_bh(&pmc->lock);
567 			if (pmc->sfcount[MCAST_EXCLUDE])
568 				type = IGMPV3_MODE_IS_EXCLUDE;
569 			else
570 				type = IGMPV3_MODE_IS_INCLUDE;
571 			skb = add_grec(skb, pmc, type, 0, 0);
572 			spin_unlock_bh(&pmc->lock);
573 		}
574 		rcu_read_unlock();
575 	} else {
576 		spin_lock_bh(&pmc->lock);
577 		if (pmc->sfcount[MCAST_EXCLUDE])
578 			type = IGMPV3_MODE_IS_EXCLUDE;
579 		else
580 			type = IGMPV3_MODE_IS_INCLUDE;
581 		skb = add_grec(skb, pmc, type, 0, 0);
582 		spin_unlock_bh(&pmc->lock);
583 	}
584 	if (!skb)
585 		return 0;
586 	return igmpv3_sendpack(skb);
587 }
588 
589 /*
590  * remove zero-count source records from a source filter list
591  */
592 static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
593 {
594 	struct ip_sf_list *psf_prev, *psf_next, *psf;
595 
596 	psf_prev = NULL;
597 	for (psf = *ppsf; psf; psf = psf_next) {
598 		psf_next = psf->sf_next;
599 		if (psf->sf_crcount == 0) {
600 			if (psf_prev)
601 				psf_prev->sf_next = psf->sf_next;
602 			else
603 				*ppsf = psf->sf_next;
604 			kfree(psf);
605 		} else
606 			psf_prev = psf;
607 	}
608 }
609 
610 static void igmpv3_send_cr(struct in_device *in_dev)
611 {
612 	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
613 	struct sk_buff *skb = NULL;
614 	int type, dtype;
615 
616 	rcu_read_lock();
617 	spin_lock_bh(&in_dev->mc_tomb_lock);
618 
619 	/* deleted MCA's */
620 	pmc_prev = NULL;
621 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
622 		pmc_next = pmc->next;
623 		if (pmc->sfmode == MCAST_INCLUDE) {
624 			type = IGMPV3_BLOCK_OLD_SOURCES;
625 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
626 			skb = add_grec(skb, pmc, type, 1, 0);
627 			skb = add_grec(skb, pmc, dtype, 1, 1);
628 		}
629 		if (pmc->crcount) {
630 			if (pmc->sfmode == MCAST_EXCLUDE) {
631 				type = IGMPV3_CHANGE_TO_INCLUDE;
632 				skb = add_grec(skb, pmc, type, 1, 0);
633 			}
634 			pmc->crcount--;
635 			if (pmc->crcount == 0) {
636 				igmpv3_clear_zeros(&pmc->tomb);
637 				igmpv3_clear_zeros(&pmc->sources);
638 			}
639 		}
640 		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
641 			if (pmc_prev)
642 				pmc_prev->next = pmc_next;
643 			else
644 				in_dev->mc_tomb = pmc_next;
645 			in_dev_put(pmc->interface);
646 			kfree(pmc);
647 		} else
648 			pmc_prev = pmc;
649 	}
650 	spin_unlock_bh(&in_dev->mc_tomb_lock);
651 
652 	/* change recs */
653 	for_each_pmc_rcu(in_dev, pmc) {
654 		spin_lock_bh(&pmc->lock);
655 		if (pmc->sfcount[MCAST_EXCLUDE]) {
656 			type = IGMPV3_BLOCK_OLD_SOURCES;
657 			dtype = IGMPV3_ALLOW_NEW_SOURCES;
658 		} else {
659 			type = IGMPV3_ALLOW_NEW_SOURCES;
660 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
661 		}
662 		skb = add_grec(skb, pmc, type, 0, 0);
663 		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
664 
665 		/* filter mode changes */
666 		if (pmc->crcount) {
667 			if (pmc->sfmode == MCAST_EXCLUDE)
668 				type = IGMPV3_CHANGE_TO_EXCLUDE;
669 			else
670 				type = IGMPV3_CHANGE_TO_INCLUDE;
671 			skb = add_grec(skb, pmc, type, 0, 0);
672 			pmc->crcount--;
673 		}
674 		spin_unlock_bh(&pmc->lock);
675 	}
676 	rcu_read_unlock();
677 
678 	if (!skb)
679 		return;
680 	(void) igmpv3_sendpack(skb);
681 }
682 
683 static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
684 	int type)
685 {
686 	struct sk_buff *skb;
687 	struct iphdr *iph;
688 	struct igmphdr *ih;
689 	struct rtable *rt;
690 	struct net_device *dev = in_dev->dev;
691 	struct net *net = dev_net(dev);
692 	__be32	group = pmc ? pmc->multiaddr : 0;
693 	struct flowi4 fl4;
694 	__be32	dst;
695 	int hlen, tlen;
696 
697 	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
698 		return igmpv3_send_report(in_dev, pmc);
699 
700 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
701 		return 0;
702 
703 	if (type == IGMP_HOST_LEAVE_MESSAGE)
704 		dst = IGMP_ALL_ROUTER;
705 	else
706 		dst = group;
707 
708 	rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
709 				   0, 0,
710 				   IPPROTO_IGMP, 0, dev->ifindex);
711 	if (IS_ERR(rt))
712 		return -1;
713 
714 	hlen = LL_RESERVED_SPACE(dev);
715 	tlen = dev->needed_tailroom;
716 	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
717 	if (!skb) {
718 		ip_rt_put(rt);
719 		return -1;
720 	}
721 	skb->priority = TC_PRIO_CONTROL;
722 
723 	skb_dst_set(skb, &rt->dst);
724 
725 	skb_reserve(skb, hlen);
726 
727 	skb_reset_network_header(skb);
728 	iph = ip_hdr(skb);
729 	skb_put(skb, sizeof(struct iphdr) + 4);
730 
731 	iph->version  = 4;
732 	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
733 	iph->tos      = 0xc0;
734 	iph->frag_off = htons(IP_DF);
735 	iph->ttl      = 1;
736 	iph->daddr    = dst;
737 	iph->saddr    = fl4.saddr;
738 	iph->protocol = IPPROTO_IGMP;
739 	ip_select_ident(net, skb, NULL);
740 	((u8 *)&iph[1])[0] = IPOPT_RA;
741 	((u8 *)&iph[1])[1] = 4;
742 	((u8 *)&iph[1])[2] = 0;
743 	((u8 *)&iph[1])[3] = 0;
744 
745 	ih = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
746 	ih->type = type;
747 	ih->code = 0;
748 	ih->csum = 0;
749 	ih->group = group;
750 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
751 
752 	return ip_local_out(net, skb->sk, skb);
753 }
754 
755 static void igmp_gq_timer_expire(unsigned long data)
756 {
757 	struct in_device *in_dev = (struct in_device *)data;
758 
759 	in_dev->mr_gq_running = 0;
760 	igmpv3_send_report(in_dev, NULL);
761 	in_dev_put(in_dev);
762 }
763 
764 static void igmp_ifc_timer_expire(unsigned long data)
765 {
766 	struct in_device *in_dev = (struct in_device *)data;
767 
768 	igmpv3_send_cr(in_dev);
769 	if (in_dev->mr_ifc_count) {
770 		in_dev->mr_ifc_count--;
771 		igmp_ifc_start_timer(in_dev,
772 				     unsolicited_report_interval(in_dev));
773 	}
774 	in_dev_put(in_dev);
775 }
776 
777 static void igmp_ifc_event(struct in_device *in_dev)
778 {
779 	struct net *net = dev_net(in_dev->dev);
780 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
781 		return;
782 	in_dev->mr_ifc_count = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
783 	igmp_ifc_start_timer(in_dev, 1);
784 }
785 
786 
787 static void igmp_timer_expire(unsigned long data)
788 {
789 	struct ip_mc_list *im = (struct ip_mc_list *)data;
790 	struct in_device *in_dev = im->interface;
791 
792 	spin_lock(&im->lock);
793 	im->tm_running = 0;
794 
795 	if (im->unsolicit_count) {
796 		im->unsolicit_count--;
797 		igmp_start_timer(im, unsolicited_report_interval(in_dev));
798 	}
799 	im->reporter = 1;
800 	spin_unlock(&im->lock);
801 
802 	if (IGMP_V1_SEEN(in_dev))
803 		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
804 	else if (IGMP_V2_SEEN(in_dev))
805 		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
806 	else
807 		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
808 
809 	ip_ma_put(im);
810 }
811 
812 /* mark EXCLUDE-mode sources */
813 static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
814 {
815 	struct ip_sf_list *psf;
816 	int i, scount;
817 
818 	scount = 0;
819 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
820 		if (scount == nsrcs)
821 			break;
822 		for (i = 0; i < nsrcs; i++) {
823 			/* skip inactive filters */
824 			if (psf->sf_count[MCAST_INCLUDE] ||
825 			    pmc->sfcount[MCAST_EXCLUDE] !=
826 			    psf->sf_count[MCAST_EXCLUDE])
827 				break;
828 			if (srcs[i] == psf->sf_inaddr) {
829 				scount++;
830 				break;
831 			}
832 		}
833 	}
834 	pmc->gsquery = 0;
835 	if (scount == nsrcs)	/* all sources excluded */
836 		return 0;
837 	return 1;
838 }
839 
840 static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
841 {
842 	struct ip_sf_list *psf;
843 	int i, scount;
844 
845 	if (pmc->sfmode == MCAST_EXCLUDE)
846 		return igmp_xmarksources(pmc, nsrcs, srcs);
847 
848 	/* mark INCLUDE-mode sources */
849 	scount = 0;
850 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
851 		if (scount == nsrcs)
852 			break;
853 		for (i = 0; i < nsrcs; i++)
854 			if (srcs[i] == psf->sf_inaddr) {
855 				psf->sf_gsresp = 1;
856 				scount++;
857 				break;
858 			}
859 	}
860 	if (!scount) {
861 		pmc->gsquery = 0;
862 		return 0;
863 	}
864 	pmc->gsquery = 1;
865 	return 1;
866 }
867 
868 /* return true if packet was dropped */
869 static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
870 {
871 	struct ip_mc_list *im;
872 	struct net *net = dev_net(in_dev->dev);
873 
874 	/* Timers are only set for non-local groups */
875 
876 	if (group == IGMP_ALL_HOSTS)
877 		return false;
878 	if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
879 		return false;
880 
881 	rcu_read_lock();
882 	for_each_pmc_rcu(in_dev, im) {
883 		if (im->multiaddr == group) {
884 			igmp_stop_timer(im);
885 			break;
886 		}
887 	}
888 	rcu_read_unlock();
889 	return false;
890 }
891 
892 /* return true if packet was dropped */
893 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
894 	int len)
895 {
896 	struct igmphdr 		*ih = igmp_hdr(skb);
897 	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
898 	struct ip_mc_list	*im;
899 	__be32			group = ih->group;
900 	int			max_delay;
901 	int			mark = 0;
902 	struct net		*net = dev_net(in_dev->dev);
903 
904 
905 	if (len == 8) {
906 		if (ih->code == 0) {
907 			/* Alas, old v1 router presents here. */
908 
909 			max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
910 			in_dev->mr_v1_seen = jiffies +
911 				IGMP_V1_ROUTER_PRESENT_TIMEOUT;
912 			group = 0;
913 		} else {
914 			/* v2 router present */
915 			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
916 			in_dev->mr_v2_seen = jiffies +
917 				IGMP_V2_ROUTER_PRESENT_TIMEOUT;
918 		}
919 		/* cancel the interface change timer */
920 		in_dev->mr_ifc_count = 0;
921 		if (del_timer(&in_dev->mr_ifc_timer))
922 			__in_dev_put(in_dev);
923 		/* clear deleted report items */
924 		igmpv3_clear_delrec(in_dev);
925 	} else if (len < 12) {
926 		return true;	/* ignore bogus packet; freed by caller */
927 	} else if (IGMP_V1_SEEN(in_dev)) {
928 		/* This is a v3 query with v1 queriers present */
929 		max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
930 		group = 0;
931 	} else if (IGMP_V2_SEEN(in_dev)) {
932 		/* this is a v3 query with v2 queriers present;
933 		 * Interpretation of the max_delay code is problematic here.
934 		 * A real v2 host would use ih_code directly, while v3 has a
935 		 * different encoding. We use the v3 encoding as more likely
936 		 * to be intended in a v3 query.
937 		 */
938 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
939 		if (!max_delay)
940 			max_delay = 1;	/* can't mod w/ 0 */
941 	} else { /* v3 */
942 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
943 			return true;
944 
945 		ih3 = igmpv3_query_hdr(skb);
946 		if (ih3->nsrcs) {
947 			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
948 					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
949 				return true;
950 			ih3 = igmpv3_query_hdr(skb);
951 		}
952 
953 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
954 		if (!max_delay)
955 			max_delay = 1;	/* can't mod w/ 0 */
956 		in_dev->mr_maxdelay = max_delay;
957 		if (ih3->qrv)
958 			in_dev->mr_qrv = ih3->qrv;
959 		if (!group) { /* general query */
960 			if (ih3->nsrcs)
961 				return true;	/* no sources allowed */
962 			igmp_gq_start_timer(in_dev);
963 			return false;
964 		}
965 		/* mark sources to include, if group & source-specific */
966 		mark = ih3->nsrcs != 0;
967 	}
968 
969 	/*
970 	 * - Start the timers in all of our membership records
971 	 *   that the query applies to for the interface on
972 	 *   which the query arrived excl. those that belong
973 	 *   to a "local" group (224.0.0.X)
974 	 * - For timers already running check if they need to
975 	 *   be reset.
976 	 * - Use the igmp->igmp_code field as the maximum
977 	 *   delay possible
978 	 */
979 	rcu_read_lock();
980 	for_each_pmc_rcu(in_dev, im) {
981 		int changed;
982 
983 		if (group && group != im->multiaddr)
984 			continue;
985 		if (im->multiaddr == IGMP_ALL_HOSTS)
986 			continue;
987 		if (ipv4_is_local_multicast(im->multiaddr) &&
988 		    !net->ipv4.sysctl_igmp_llm_reports)
989 			continue;
990 		spin_lock_bh(&im->lock);
991 		if (im->tm_running)
992 			im->gsquery = im->gsquery && mark;
993 		else
994 			im->gsquery = mark;
995 		changed = !im->gsquery ||
996 			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
997 		spin_unlock_bh(&im->lock);
998 		if (changed)
999 			igmp_mod_timer(im, max_delay);
1000 	}
1001 	rcu_read_unlock();
1002 	return false;
1003 }
1004 
1005 /* called in rcu_read_lock() section */
1006 int igmp_rcv(struct sk_buff *skb)
1007 {
1008 	/* This basically follows the spec line by line -- see RFC1112 */
1009 	struct igmphdr *ih;
1010 	struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
1011 	int len = skb->len;
1012 	bool dropped = true;
1013 
1014 	if (!in_dev)
1015 		goto drop;
1016 
1017 	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
1018 		goto drop;
1019 
1020 	if (skb_checksum_simple_validate(skb))
1021 		goto drop;
1022 
1023 	ih = igmp_hdr(skb);
1024 	switch (ih->type) {
1025 	case IGMP_HOST_MEMBERSHIP_QUERY:
1026 		dropped = igmp_heard_query(in_dev, skb, len);
1027 		break;
1028 	case IGMP_HOST_MEMBERSHIP_REPORT:
1029 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1030 		/* Is it our report looped back? */
1031 		if (rt_is_output_route(skb_rtable(skb)))
1032 			break;
1033 		/* don't rely on MC router hearing unicast reports */
1034 		if (skb->pkt_type == PACKET_MULTICAST ||
1035 		    skb->pkt_type == PACKET_BROADCAST)
1036 			dropped = igmp_heard_report(in_dev, ih->group);
1037 		break;
1038 	case IGMP_PIM:
1039 #ifdef CONFIG_IP_PIMSM_V1
1040 		return pim_rcv_v1(skb);
1041 #endif
1042 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1043 	case IGMP_DVMRP:
1044 	case IGMP_TRACE:
1045 	case IGMP_HOST_LEAVE_MESSAGE:
1046 	case IGMP_MTRACE:
1047 	case IGMP_MTRACE_RESP:
1048 		break;
1049 	default:
1050 		break;
1051 	}
1052 
1053 drop:
1054 	if (dropped)
1055 		kfree_skb(skb);
1056 	else
1057 		consume_skb(skb);
1058 	return 0;
1059 }
1060 
1061 #endif
1062 
1063 
1064 /*
1065  *	Add a filter to a device
1066  */
1067 
1068 static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
1069 {
1070 	char buf[MAX_ADDR_LEN];
1071 	struct net_device *dev = in_dev->dev;
1072 
1073 	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
1074 	   We will get multicast token leakage, when IFF_MULTICAST
1075 	   is changed. This check should be done in ndo_set_rx_mode
1076 	   routine. Something sort of:
1077 	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
1078 	   --ANK
1079 	   */
1080 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1081 		dev_mc_add(dev, buf);
1082 }
1083 
1084 /*
1085  *	Remove a filter from a device
1086  */
1087 
1088 static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
1089 {
1090 	char buf[MAX_ADDR_LEN];
1091 	struct net_device *dev = in_dev->dev;
1092 
1093 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1094 		dev_mc_del(dev, buf);
1095 }
1096 
1097 #ifdef CONFIG_IP_MULTICAST
1098 /*
1099  * deleted ip_mc_list manipulation
1100  */
1101 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1102 {
1103 	struct ip_mc_list *pmc;
1104 	struct net *net = dev_net(in_dev->dev);
1105 
1106 	/* this is an "ip_mc_list" for convenience; only the fields below
1107 	 * are actually used. In particular, the refcnt and users are not
1108 	 * used for management of the delete list. Using the same structure
1109 	 * for deleted items allows change reports to use common code with
1110 	 * non-deleted or query-response MCA's.
1111 	 */
1112 	pmc = kzalloc(sizeof(*pmc), GFP_KERNEL);
1113 	if (!pmc)
1114 		return;
1115 	spin_lock_bh(&im->lock);
1116 	pmc->interface = im->interface;
1117 	in_dev_hold(in_dev);
1118 	pmc->multiaddr = im->multiaddr;
1119 	pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1120 	pmc->sfmode = im->sfmode;
1121 	if (pmc->sfmode == MCAST_INCLUDE) {
1122 		struct ip_sf_list *psf;
1123 
1124 		pmc->tomb = im->tomb;
1125 		pmc->sources = im->sources;
1126 		im->tomb = im->sources = NULL;
1127 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1128 			psf->sf_crcount = pmc->crcount;
1129 	}
1130 	spin_unlock_bh(&im->lock);
1131 
1132 	spin_lock_bh(&in_dev->mc_tomb_lock);
1133 	pmc->next = in_dev->mc_tomb;
1134 	in_dev->mc_tomb = pmc;
1135 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1136 }
1137 
1138 /*
1139  * restore ip_mc_list deleted records
1140  */
1141 static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1142 {
1143 	struct ip_mc_list *pmc, *pmc_prev;
1144 	struct ip_sf_list *psf;
1145 	struct net *net = dev_net(in_dev->dev);
1146 	__be32 multiaddr = im->multiaddr;
1147 
1148 	spin_lock_bh(&in_dev->mc_tomb_lock);
1149 	pmc_prev = NULL;
1150 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
1151 		if (pmc->multiaddr == multiaddr)
1152 			break;
1153 		pmc_prev = pmc;
1154 	}
1155 	if (pmc) {
1156 		if (pmc_prev)
1157 			pmc_prev->next = pmc->next;
1158 		else
1159 			in_dev->mc_tomb = pmc->next;
1160 	}
1161 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1162 
1163 	spin_lock_bh(&im->lock);
1164 	if (pmc) {
1165 		im->interface = pmc->interface;
1166 		im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1167 		im->sfmode = pmc->sfmode;
1168 		if (pmc->sfmode == MCAST_INCLUDE) {
1169 			im->tomb = pmc->tomb;
1170 			im->sources = pmc->sources;
1171 			for (psf = im->sources; psf; psf = psf->sf_next)
1172 				psf->sf_crcount = im->crcount;
1173 		}
1174 		in_dev_put(pmc->interface);
1175 		kfree(pmc);
1176 	}
1177 	spin_unlock_bh(&im->lock);
1178 }
1179 
1180 /*
1181  * flush ip_mc_list deleted records
1182  */
1183 static void igmpv3_clear_delrec(struct in_device *in_dev)
1184 {
1185 	struct ip_mc_list *pmc, *nextpmc;
1186 
1187 	spin_lock_bh(&in_dev->mc_tomb_lock);
1188 	pmc = in_dev->mc_tomb;
1189 	in_dev->mc_tomb = NULL;
1190 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1191 
1192 	for (; pmc; pmc = nextpmc) {
1193 		nextpmc = pmc->next;
1194 		ip_mc_clear_src(pmc);
1195 		in_dev_put(pmc->interface);
1196 		kfree(pmc);
1197 	}
1198 	/* clear dead sources, too */
1199 	rcu_read_lock();
1200 	for_each_pmc_rcu(in_dev, pmc) {
1201 		struct ip_sf_list *psf, *psf_next;
1202 
1203 		spin_lock_bh(&pmc->lock);
1204 		psf = pmc->tomb;
1205 		pmc->tomb = NULL;
1206 		spin_unlock_bh(&pmc->lock);
1207 		for (; psf; psf = psf_next) {
1208 			psf_next = psf->sf_next;
1209 			kfree(psf);
1210 		}
1211 	}
1212 	rcu_read_unlock();
1213 }
1214 #endif
1215 
1216 static void igmp_group_dropped(struct ip_mc_list *im)
1217 {
1218 	struct in_device *in_dev = im->interface;
1219 #ifdef CONFIG_IP_MULTICAST
1220 	struct net *net = dev_net(in_dev->dev);
1221 	int reporter;
1222 #endif
1223 
1224 	if (im->loaded) {
1225 		im->loaded = 0;
1226 		ip_mc_filter_del(in_dev, im->multiaddr);
1227 	}
1228 
1229 #ifdef CONFIG_IP_MULTICAST
1230 	if (im->multiaddr == IGMP_ALL_HOSTS)
1231 		return;
1232 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1233 		return;
1234 
1235 	reporter = im->reporter;
1236 	igmp_stop_timer(im);
1237 
1238 	if (!in_dev->dead) {
1239 		if (IGMP_V1_SEEN(in_dev))
1240 			return;
1241 		if (IGMP_V2_SEEN(in_dev)) {
1242 			if (reporter)
1243 				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
1244 			return;
1245 		}
1246 		/* IGMPv3 */
1247 		igmpv3_add_delrec(in_dev, im);
1248 
1249 		igmp_ifc_event(in_dev);
1250 	}
1251 #endif
1252 }
1253 
1254 static void igmp_group_added(struct ip_mc_list *im)
1255 {
1256 	struct in_device *in_dev = im->interface;
1257 #ifdef CONFIG_IP_MULTICAST
1258 	struct net *net = dev_net(in_dev->dev);
1259 #endif
1260 
1261 	if (im->loaded == 0) {
1262 		im->loaded = 1;
1263 		ip_mc_filter_add(in_dev, im->multiaddr);
1264 	}
1265 
1266 #ifdef CONFIG_IP_MULTICAST
1267 	if (im->multiaddr == IGMP_ALL_HOSTS)
1268 		return;
1269 	if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1270 		return;
1271 
1272 	if (in_dev->dead)
1273 		return;
1274 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
1275 		spin_lock_bh(&im->lock);
1276 		igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
1277 		spin_unlock_bh(&im->lock);
1278 		return;
1279 	}
1280 	/* else, v3 */
1281 
1282 	im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1283 	igmp_ifc_event(in_dev);
1284 #endif
1285 }
1286 
1287 
1288 /*
1289  *	Multicast list managers
1290  */
1291 
1292 static u32 ip_mc_hash(const struct ip_mc_list *im)
1293 {
1294 	return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
1295 }
1296 
1297 static void ip_mc_hash_add(struct in_device *in_dev,
1298 			   struct ip_mc_list *im)
1299 {
1300 	struct ip_mc_list __rcu **mc_hash;
1301 	u32 hash;
1302 
1303 	mc_hash = rtnl_dereference(in_dev->mc_hash);
1304 	if (mc_hash) {
1305 		hash = ip_mc_hash(im);
1306 		im->next_hash = mc_hash[hash];
1307 		rcu_assign_pointer(mc_hash[hash], im);
1308 		return;
1309 	}
1310 
1311 	/* do not use a hash table for small number of items */
1312 	if (in_dev->mc_count < 4)
1313 		return;
1314 
1315 	mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
1316 			  GFP_KERNEL);
1317 	if (!mc_hash)
1318 		return;
1319 
1320 	for_each_pmc_rtnl(in_dev, im) {
1321 		hash = ip_mc_hash(im);
1322 		im->next_hash = mc_hash[hash];
1323 		RCU_INIT_POINTER(mc_hash[hash], im);
1324 	}
1325 
1326 	rcu_assign_pointer(in_dev->mc_hash, mc_hash);
1327 }
1328 
1329 static void ip_mc_hash_remove(struct in_device *in_dev,
1330 			      struct ip_mc_list *im)
1331 {
1332 	struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
1333 	struct ip_mc_list *aux;
1334 
1335 	if (!mc_hash)
1336 		return;
1337 	mc_hash += ip_mc_hash(im);
1338 	while ((aux = rtnl_dereference(*mc_hash)) != im)
1339 		mc_hash = &aux->next_hash;
1340 	*mc_hash = im->next_hash;
1341 }
1342 
1343 
1344 /*
1345  *	A socket has joined a multicast group on device dev.
1346  */
1347 
1348 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
1349 {
1350 	struct ip_mc_list *im;
1351 #ifdef CONFIG_IP_MULTICAST
1352 	struct net *net = dev_net(in_dev->dev);
1353 #endif
1354 
1355 	ASSERT_RTNL();
1356 
1357 	for_each_pmc_rtnl(in_dev, im) {
1358 		if (im->multiaddr == addr) {
1359 			im->users++;
1360 			ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, NULL, 0);
1361 			goto out;
1362 		}
1363 	}
1364 
1365 	im = kzalloc(sizeof(*im), GFP_KERNEL);
1366 	if (!im)
1367 		goto out;
1368 
1369 	im->users = 1;
1370 	im->interface = in_dev;
1371 	in_dev_hold(in_dev);
1372 	im->multiaddr = addr;
1373 	/* initial mode is (EX, empty) */
1374 	im->sfmode = MCAST_EXCLUDE;
1375 	im->sfcount[MCAST_EXCLUDE] = 1;
1376 	atomic_set(&im->refcnt, 1);
1377 	spin_lock_init(&im->lock);
1378 #ifdef CONFIG_IP_MULTICAST
1379 	setup_timer(&im->timer, igmp_timer_expire, (unsigned long)im);
1380 	im->unsolicit_count = net->ipv4.sysctl_igmp_qrv;
1381 #endif
1382 
1383 	im->next_rcu = in_dev->mc_list;
1384 	in_dev->mc_count++;
1385 	rcu_assign_pointer(in_dev->mc_list, im);
1386 
1387 	ip_mc_hash_add(in_dev, im);
1388 
1389 #ifdef CONFIG_IP_MULTICAST
1390 	igmpv3_del_delrec(in_dev, im);
1391 #endif
1392 	igmp_group_added(im);
1393 	if (!in_dev->dead)
1394 		ip_rt_multicast_event(in_dev);
1395 out:
1396 	return;
1397 }
1398 EXPORT_SYMBOL(ip_mc_inc_group);
1399 
1400 static int ip_mc_check_iphdr(struct sk_buff *skb)
1401 {
1402 	const struct iphdr *iph;
1403 	unsigned int len;
1404 	unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
1405 
1406 	if (!pskb_may_pull(skb, offset))
1407 		return -EINVAL;
1408 
1409 	iph = ip_hdr(skb);
1410 
1411 	if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
1412 		return -EINVAL;
1413 
1414 	offset += ip_hdrlen(skb) - sizeof(*iph);
1415 
1416 	if (!pskb_may_pull(skb, offset))
1417 		return -EINVAL;
1418 
1419 	iph = ip_hdr(skb);
1420 
1421 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1422 		return -EINVAL;
1423 
1424 	len = skb_network_offset(skb) + ntohs(iph->tot_len);
1425 	if (skb->len < len || len < offset)
1426 		return -EINVAL;
1427 
1428 	skb_set_transport_header(skb, offset);
1429 
1430 	return 0;
1431 }
1432 
1433 static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
1434 {
1435 	unsigned int len = skb_transport_offset(skb);
1436 
1437 	len += sizeof(struct igmpv3_report);
1438 
1439 	return pskb_may_pull(skb, len) ? 0 : -EINVAL;
1440 }
1441 
1442 static int ip_mc_check_igmp_query(struct sk_buff *skb)
1443 {
1444 	unsigned int len = skb_transport_offset(skb);
1445 
1446 	len += sizeof(struct igmphdr);
1447 	if (skb->len < len)
1448 		return -EINVAL;
1449 
1450 	/* IGMPv{1,2}? */
1451 	if (skb->len != len) {
1452 		/* or IGMPv3? */
1453 		len += sizeof(struct igmpv3_query) - sizeof(struct igmphdr);
1454 		if (skb->len < len || !pskb_may_pull(skb, len))
1455 			return -EINVAL;
1456 	}
1457 
1458 	/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
1459 	 * all-systems destination addresses (224.0.0.1) for general queries
1460 	 */
1461 	if (!igmp_hdr(skb)->group &&
1462 	    ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
1463 		return -EINVAL;
1464 
1465 	return 0;
1466 }
1467 
1468 static int ip_mc_check_igmp_msg(struct sk_buff *skb)
1469 {
1470 	switch (igmp_hdr(skb)->type) {
1471 	case IGMP_HOST_LEAVE_MESSAGE:
1472 	case IGMP_HOST_MEMBERSHIP_REPORT:
1473 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1474 		/* fall through */
1475 		return 0;
1476 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1477 		return ip_mc_check_igmp_reportv3(skb);
1478 	case IGMP_HOST_MEMBERSHIP_QUERY:
1479 		return ip_mc_check_igmp_query(skb);
1480 	default:
1481 		return -ENOMSG;
1482 	}
1483 }
1484 
1485 static inline __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
1486 {
1487 	return skb_checksum_simple_validate(skb);
1488 }
1489 
1490 static int __ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
1491 
1492 {
1493 	struct sk_buff *skb_chk;
1494 	unsigned int transport_len;
1495 	unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
1496 	int ret = -EINVAL;
1497 
1498 	transport_len = ntohs(ip_hdr(skb)->tot_len) - ip_hdrlen(skb);
1499 
1500 	skb_chk = skb_checksum_trimmed(skb, transport_len,
1501 				       ip_mc_validate_checksum);
1502 	if (!skb_chk)
1503 		goto err;
1504 
1505 	if (!pskb_may_pull(skb_chk, len))
1506 		goto err;
1507 
1508 	ret = ip_mc_check_igmp_msg(skb_chk);
1509 	if (ret)
1510 		goto err;
1511 
1512 	if (skb_trimmed)
1513 		*skb_trimmed = skb_chk;
1514 	/* free now unneeded clone */
1515 	else if (skb_chk != skb)
1516 		kfree_skb(skb_chk);
1517 
1518 	ret = 0;
1519 
1520 err:
1521 	if (ret && skb_chk && skb_chk != skb)
1522 		kfree_skb(skb_chk);
1523 
1524 	return ret;
1525 }
1526 
1527 /**
1528  * ip_mc_check_igmp - checks whether this is a sane IGMP packet
1529  * @skb: the skb to validate
1530  * @skb_trimmed: to store an skb pointer trimmed to IPv4 packet tail (optional)
1531  *
1532  * Checks whether an IPv4 packet is a valid IGMP packet. If so sets
1533  * skb transport header accordingly and returns zero.
1534  *
1535  * -EINVAL: A broken packet was detected, i.e. it violates some internet
1536  *  standard
1537  * -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
1538  * -ENOMEM: A memory allocation failure happened.
1539  *
1540  * Optionally, an skb pointer might be provided via skb_trimmed (or set it
1541  * to NULL): After parsing an IGMP packet successfully it will point to
1542  * an skb which has its tail aligned to the IP packet end. This might
1543  * either be the originally provided skb or a trimmed, cloned version if
1544  * the skb frame had data beyond the IP packet. A cloned skb allows us
1545  * to leave the original skb and its full frame unchanged (which might be
1546  * desirable for layer 2 frame jugglers).
1547  *
1548  * Caller needs to set the skb network header and free any returned skb if it
1549  * differs from the provided skb.
1550  */
1551 int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
1552 {
1553 	int ret = ip_mc_check_iphdr(skb);
1554 
1555 	if (ret < 0)
1556 		return ret;
1557 
1558 	if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
1559 		return -ENOMSG;
1560 
1561 	return __ip_mc_check_igmp(skb, skb_trimmed);
1562 }
1563 EXPORT_SYMBOL(ip_mc_check_igmp);
1564 
1565 /*
1566  *	Resend IGMP JOIN report; used by netdev notifier.
1567  */
1568 static void ip_mc_rejoin_groups(struct in_device *in_dev)
1569 {
1570 #ifdef CONFIG_IP_MULTICAST
1571 	struct ip_mc_list *im;
1572 	int type;
1573 	struct net *net = dev_net(in_dev->dev);
1574 
1575 	ASSERT_RTNL();
1576 
1577 	for_each_pmc_rtnl(in_dev, im) {
1578 		if (im->multiaddr == IGMP_ALL_HOSTS)
1579 			continue;
1580 		if (ipv4_is_local_multicast(im->multiaddr) &&
1581 		    !net->ipv4.sysctl_igmp_llm_reports)
1582 			continue;
1583 
1584 		/* a failover is happening and switches
1585 		 * must be notified immediately
1586 		 */
1587 		if (IGMP_V1_SEEN(in_dev))
1588 			type = IGMP_HOST_MEMBERSHIP_REPORT;
1589 		else if (IGMP_V2_SEEN(in_dev))
1590 			type = IGMPV2_HOST_MEMBERSHIP_REPORT;
1591 		else
1592 			type = IGMPV3_HOST_MEMBERSHIP_REPORT;
1593 		igmp_send_report(in_dev, im, type);
1594 	}
1595 #endif
1596 }
1597 
1598 /*
1599  *	A socket has left a multicast group on device dev
1600  */
1601 
1602 void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
1603 {
1604 	struct ip_mc_list *i;
1605 	struct ip_mc_list __rcu **ip;
1606 
1607 	ASSERT_RTNL();
1608 
1609 	for (ip = &in_dev->mc_list;
1610 	     (i = rtnl_dereference(*ip)) != NULL;
1611 	     ip = &i->next_rcu) {
1612 		if (i->multiaddr == addr) {
1613 			if (--i->users == 0) {
1614 				ip_mc_hash_remove(in_dev, i);
1615 				*ip = i->next_rcu;
1616 				in_dev->mc_count--;
1617 				igmp_group_dropped(i);
1618 				ip_mc_clear_src(i);
1619 
1620 				if (!in_dev->dead)
1621 					ip_rt_multicast_event(in_dev);
1622 
1623 				ip_ma_put(i);
1624 				return;
1625 			}
1626 			break;
1627 		}
1628 	}
1629 }
1630 EXPORT_SYMBOL(ip_mc_dec_group);
1631 
1632 /* Device changing type */
1633 
1634 void ip_mc_unmap(struct in_device *in_dev)
1635 {
1636 	struct ip_mc_list *pmc;
1637 
1638 	ASSERT_RTNL();
1639 
1640 	for_each_pmc_rtnl(in_dev, pmc)
1641 		igmp_group_dropped(pmc);
1642 }
1643 
1644 void ip_mc_remap(struct in_device *in_dev)
1645 {
1646 	struct ip_mc_list *pmc;
1647 
1648 	ASSERT_RTNL();
1649 
1650 	for_each_pmc_rtnl(in_dev, pmc) {
1651 #ifdef CONFIG_IP_MULTICAST
1652 		igmpv3_del_delrec(in_dev, pmc);
1653 #endif
1654 		igmp_group_added(pmc);
1655 	}
1656 }
1657 
1658 /* Device going down */
1659 
1660 void ip_mc_down(struct in_device *in_dev)
1661 {
1662 	struct ip_mc_list *pmc;
1663 
1664 	ASSERT_RTNL();
1665 
1666 	for_each_pmc_rtnl(in_dev, pmc)
1667 		igmp_group_dropped(pmc);
1668 
1669 #ifdef CONFIG_IP_MULTICAST
1670 	in_dev->mr_ifc_count = 0;
1671 	if (del_timer(&in_dev->mr_ifc_timer))
1672 		__in_dev_put(in_dev);
1673 	in_dev->mr_gq_running = 0;
1674 	if (del_timer(&in_dev->mr_gq_timer))
1675 		__in_dev_put(in_dev);
1676 #endif
1677 
1678 	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
1679 }
1680 
1681 void ip_mc_init_dev(struct in_device *in_dev)
1682 {
1683 #ifdef CONFIG_IP_MULTICAST
1684 	struct net *net = dev_net(in_dev->dev);
1685 #endif
1686 	ASSERT_RTNL();
1687 
1688 #ifdef CONFIG_IP_MULTICAST
1689 	setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
1690 			(unsigned long)in_dev);
1691 	setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
1692 			(unsigned long)in_dev);
1693 	in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
1694 #endif
1695 
1696 	spin_lock_init(&in_dev->mc_tomb_lock);
1697 }
1698 
1699 /* Device going up */
1700 
1701 void ip_mc_up(struct in_device *in_dev)
1702 {
1703 	struct ip_mc_list *pmc;
1704 #ifdef CONFIG_IP_MULTICAST
1705 	struct net *net = dev_net(in_dev->dev);
1706 #endif
1707 
1708 	ASSERT_RTNL();
1709 
1710 #ifdef CONFIG_IP_MULTICAST
1711 	in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
1712 #endif
1713 	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
1714 
1715 	for_each_pmc_rtnl(in_dev, pmc) {
1716 #ifdef CONFIG_IP_MULTICAST
1717 		igmpv3_del_delrec(in_dev, pmc);
1718 #endif
1719 		igmp_group_added(pmc);
1720 	}
1721 }
1722 
1723 /*
1724  *	Device is about to be destroyed: clean up.
1725  */
1726 
1727 void ip_mc_destroy_dev(struct in_device *in_dev)
1728 {
1729 	struct ip_mc_list *i;
1730 
1731 	ASSERT_RTNL();
1732 
1733 	/* Deactivate timers */
1734 	ip_mc_down(in_dev);
1735 #ifdef CONFIG_IP_MULTICAST
1736 	igmpv3_clear_delrec(in_dev);
1737 #endif
1738 
1739 	while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
1740 		in_dev->mc_list = i->next_rcu;
1741 		in_dev->mc_count--;
1742 		ip_ma_put(i);
1743 	}
1744 }
1745 
1746 /* RTNL is locked */
1747 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1748 {
1749 	struct net_device *dev = NULL;
1750 	struct in_device *idev = NULL;
1751 
1752 	if (imr->imr_ifindex) {
1753 		idev = inetdev_by_index(net, imr->imr_ifindex);
1754 		return idev;
1755 	}
1756 	if (imr->imr_address.s_addr) {
1757 		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1758 		if (!dev)
1759 			return NULL;
1760 	}
1761 
1762 	if (!dev) {
1763 		struct rtable *rt = ip_route_output(net,
1764 						    imr->imr_multiaddr.s_addr,
1765 						    0, 0, 0);
1766 		if (!IS_ERR(rt)) {
1767 			dev = rt->dst.dev;
1768 			ip_rt_put(rt);
1769 		}
1770 	}
1771 	if (dev) {
1772 		imr->imr_ifindex = dev->ifindex;
1773 		idev = __in_dev_get_rtnl(dev);
1774 	}
1775 	return idev;
1776 }
1777 
1778 /*
1779  *	Join a socket to a group
1780  */
1781 
1782 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1783 	__be32 *psfsrc)
1784 {
1785 	struct ip_sf_list *psf, *psf_prev;
1786 	int rv = 0;
1787 
1788 	psf_prev = NULL;
1789 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1790 		if (psf->sf_inaddr == *psfsrc)
1791 			break;
1792 		psf_prev = psf;
1793 	}
1794 	if (!psf || psf->sf_count[sfmode] == 0) {
1795 		/* source filter not found, or count wrong =>  bug */
1796 		return -ESRCH;
1797 	}
1798 	psf->sf_count[sfmode]--;
1799 	if (psf->sf_count[sfmode] == 0) {
1800 		ip_rt_multicast_event(pmc->interface);
1801 	}
1802 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1803 #ifdef CONFIG_IP_MULTICAST
1804 		struct in_device *in_dev = pmc->interface;
1805 		struct net *net = dev_net(in_dev->dev);
1806 #endif
1807 
1808 		/* no more filters for this source */
1809 		if (psf_prev)
1810 			psf_prev->sf_next = psf->sf_next;
1811 		else
1812 			pmc->sources = psf->sf_next;
1813 #ifdef CONFIG_IP_MULTICAST
1814 		if (psf->sf_oldin &&
1815 		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1816 			psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1817 			psf->sf_next = pmc->tomb;
1818 			pmc->tomb = psf;
1819 			rv = 1;
1820 		} else
1821 #endif
1822 			kfree(psf);
1823 	}
1824 	return rv;
1825 }
1826 
1827 #ifndef CONFIG_IP_MULTICAST
1828 #define igmp_ifc_event(x)	do { } while (0)
1829 #endif
1830 
1831 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1832 			 int sfcount, __be32 *psfsrc, int delta)
1833 {
1834 	struct ip_mc_list *pmc;
1835 	int	changerec = 0;
1836 	int	i, err;
1837 
1838 	if (!in_dev)
1839 		return -ENODEV;
1840 	rcu_read_lock();
1841 	for_each_pmc_rcu(in_dev, pmc) {
1842 		if (*pmca == pmc->multiaddr)
1843 			break;
1844 	}
1845 	if (!pmc) {
1846 		/* MCA not found?? bug */
1847 		rcu_read_unlock();
1848 		return -ESRCH;
1849 	}
1850 	spin_lock_bh(&pmc->lock);
1851 	rcu_read_unlock();
1852 #ifdef CONFIG_IP_MULTICAST
1853 	sf_markstate(pmc);
1854 #endif
1855 	if (!delta) {
1856 		err = -EINVAL;
1857 		if (!pmc->sfcount[sfmode])
1858 			goto out_unlock;
1859 		pmc->sfcount[sfmode]--;
1860 	}
1861 	err = 0;
1862 	for (i = 0; i < sfcount; i++) {
1863 		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1864 
1865 		changerec |= rv > 0;
1866 		if (!err && rv < 0)
1867 			err = rv;
1868 	}
1869 	if (pmc->sfmode == MCAST_EXCLUDE &&
1870 	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1871 	    pmc->sfcount[MCAST_INCLUDE]) {
1872 #ifdef CONFIG_IP_MULTICAST
1873 		struct ip_sf_list *psf;
1874 		struct net *net = dev_net(in_dev->dev);
1875 #endif
1876 
1877 		/* filter mode change */
1878 		pmc->sfmode = MCAST_INCLUDE;
1879 #ifdef CONFIG_IP_MULTICAST
1880 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1881 		in_dev->mr_ifc_count = pmc->crcount;
1882 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1883 			psf->sf_crcount = 0;
1884 		igmp_ifc_event(pmc->interface);
1885 	} else if (sf_setstate(pmc) || changerec) {
1886 		igmp_ifc_event(pmc->interface);
1887 #endif
1888 	}
1889 out_unlock:
1890 	spin_unlock_bh(&pmc->lock);
1891 	return err;
1892 }
1893 
1894 /*
1895  * Add multicast single-source filter to the interface list
1896  */
1897 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1898 	__be32 *psfsrc)
1899 {
1900 	struct ip_sf_list *psf, *psf_prev;
1901 
1902 	psf_prev = NULL;
1903 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1904 		if (psf->sf_inaddr == *psfsrc)
1905 			break;
1906 		psf_prev = psf;
1907 	}
1908 	if (!psf) {
1909 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1910 		if (!psf)
1911 			return -ENOBUFS;
1912 		psf->sf_inaddr = *psfsrc;
1913 		if (psf_prev) {
1914 			psf_prev->sf_next = psf;
1915 		} else
1916 			pmc->sources = psf;
1917 	}
1918 	psf->sf_count[sfmode]++;
1919 	if (psf->sf_count[sfmode] == 1) {
1920 		ip_rt_multicast_event(pmc->interface);
1921 	}
1922 	return 0;
1923 }
1924 
1925 #ifdef CONFIG_IP_MULTICAST
1926 static void sf_markstate(struct ip_mc_list *pmc)
1927 {
1928 	struct ip_sf_list *psf;
1929 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1930 
1931 	for (psf = pmc->sources; psf; psf = psf->sf_next)
1932 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1933 			psf->sf_oldin = mca_xcount ==
1934 				psf->sf_count[MCAST_EXCLUDE] &&
1935 				!psf->sf_count[MCAST_INCLUDE];
1936 		} else
1937 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
1938 }
1939 
1940 static int sf_setstate(struct ip_mc_list *pmc)
1941 {
1942 	struct ip_sf_list *psf, *dpsf;
1943 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1944 	int qrv = pmc->interface->mr_qrv;
1945 	int new_in, rv;
1946 
1947 	rv = 0;
1948 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1949 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1950 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
1951 				!psf->sf_count[MCAST_INCLUDE];
1952 		} else
1953 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
1954 		if (new_in) {
1955 			if (!psf->sf_oldin) {
1956 				struct ip_sf_list *prev = NULL;
1957 
1958 				for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
1959 					if (dpsf->sf_inaddr == psf->sf_inaddr)
1960 						break;
1961 					prev = dpsf;
1962 				}
1963 				if (dpsf) {
1964 					if (prev)
1965 						prev->sf_next = dpsf->sf_next;
1966 					else
1967 						pmc->tomb = dpsf->sf_next;
1968 					kfree(dpsf);
1969 				}
1970 				psf->sf_crcount = qrv;
1971 				rv++;
1972 			}
1973 		} else if (psf->sf_oldin) {
1974 
1975 			psf->sf_crcount = 0;
1976 			/*
1977 			 * add or update "delete" records if an active filter
1978 			 * is now inactive
1979 			 */
1980 			for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
1981 				if (dpsf->sf_inaddr == psf->sf_inaddr)
1982 					break;
1983 			if (!dpsf) {
1984 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
1985 				if (!dpsf)
1986 					continue;
1987 				*dpsf = *psf;
1988 				/* pmc->lock held by callers */
1989 				dpsf->sf_next = pmc->tomb;
1990 				pmc->tomb = dpsf;
1991 			}
1992 			dpsf->sf_crcount = qrv;
1993 			rv++;
1994 		}
1995 	}
1996 	return rv;
1997 }
1998 #endif
1999 
2000 /*
2001  * Add multicast source filter list to the interface list
2002  */
2003 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
2004 			 int sfcount, __be32 *psfsrc, int delta)
2005 {
2006 	struct ip_mc_list *pmc;
2007 	int	isexclude;
2008 	int	i, err;
2009 
2010 	if (!in_dev)
2011 		return -ENODEV;
2012 	rcu_read_lock();
2013 	for_each_pmc_rcu(in_dev, pmc) {
2014 		if (*pmca == pmc->multiaddr)
2015 			break;
2016 	}
2017 	if (!pmc) {
2018 		/* MCA not found?? bug */
2019 		rcu_read_unlock();
2020 		return -ESRCH;
2021 	}
2022 	spin_lock_bh(&pmc->lock);
2023 	rcu_read_unlock();
2024 
2025 #ifdef CONFIG_IP_MULTICAST
2026 	sf_markstate(pmc);
2027 #endif
2028 	isexclude = pmc->sfmode == MCAST_EXCLUDE;
2029 	if (!delta)
2030 		pmc->sfcount[sfmode]++;
2031 	err = 0;
2032 	for (i = 0; i < sfcount; i++) {
2033 		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2034 		if (err)
2035 			break;
2036 	}
2037 	if (err) {
2038 		int j;
2039 
2040 		if (!delta)
2041 			pmc->sfcount[sfmode]--;
2042 		for (j = 0; j < i; j++)
2043 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2044 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
2045 #ifdef CONFIG_IP_MULTICAST
2046 		struct ip_sf_list *psf;
2047 		struct net *net = dev_net(pmc->interface->dev);
2048 		in_dev = pmc->interface;
2049 #endif
2050 
2051 		/* filter mode change */
2052 		if (pmc->sfcount[MCAST_EXCLUDE])
2053 			pmc->sfmode = MCAST_EXCLUDE;
2054 		else if (pmc->sfcount[MCAST_INCLUDE])
2055 			pmc->sfmode = MCAST_INCLUDE;
2056 #ifdef CONFIG_IP_MULTICAST
2057 		/* else no filters; keep old mode for reports */
2058 
2059 		pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
2060 		in_dev->mr_ifc_count = pmc->crcount;
2061 		for (psf = pmc->sources; psf; psf = psf->sf_next)
2062 			psf->sf_crcount = 0;
2063 		igmp_ifc_event(in_dev);
2064 	} else if (sf_setstate(pmc)) {
2065 		igmp_ifc_event(in_dev);
2066 #endif
2067 	}
2068 	spin_unlock_bh(&pmc->lock);
2069 	return err;
2070 }
2071 
2072 static void ip_mc_clear_src(struct ip_mc_list *pmc)
2073 {
2074 	struct ip_sf_list *psf, *nextpsf;
2075 
2076 	for (psf = pmc->tomb; psf; psf = nextpsf) {
2077 		nextpsf = psf->sf_next;
2078 		kfree(psf);
2079 	}
2080 	pmc->tomb = NULL;
2081 	for (psf = pmc->sources; psf; psf = nextpsf) {
2082 		nextpsf = psf->sf_next;
2083 		kfree(psf);
2084 	}
2085 	pmc->sources = NULL;
2086 	pmc->sfmode = MCAST_EXCLUDE;
2087 	pmc->sfcount[MCAST_INCLUDE] = 0;
2088 	pmc->sfcount[MCAST_EXCLUDE] = 1;
2089 }
2090 
2091 /* Join a multicast group
2092  */
2093 
2094 int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
2095 {
2096 	__be32 addr = imr->imr_multiaddr.s_addr;
2097 	struct ip_mc_socklist *iml, *i;
2098 	struct in_device *in_dev;
2099 	struct inet_sock *inet = inet_sk(sk);
2100 	struct net *net = sock_net(sk);
2101 	int ifindex;
2102 	int count = 0;
2103 	int err;
2104 
2105 	ASSERT_RTNL();
2106 
2107 	if (!ipv4_is_multicast(addr))
2108 		return -EINVAL;
2109 
2110 	in_dev = ip_mc_find_dev(net, imr);
2111 
2112 	if (!in_dev) {
2113 		err = -ENODEV;
2114 		goto done;
2115 	}
2116 
2117 	err = -EADDRINUSE;
2118 	ifindex = imr->imr_ifindex;
2119 	for_each_pmc_rtnl(inet, i) {
2120 		if (i->multi.imr_multiaddr.s_addr == addr &&
2121 		    i->multi.imr_ifindex == ifindex)
2122 			goto done;
2123 		count++;
2124 	}
2125 	err = -ENOBUFS;
2126 	if (count >= net->ipv4.sysctl_igmp_max_memberships)
2127 		goto done;
2128 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
2129 	if (!iml)
2130 		goto done;
2131 
2132 	memcpy(&iml->multi, imr, sizeof(*imr));
2133 	iml->next_rcu = inet->mc_list;
2134 	iml->sflist = NULL;
2135 	iml->sfmode = MCAST_EXCLUDE;
2136 	rcu_assign_pointer(inet->mc_list, iml);
2137 	ip_mc_inc_group(in_dev, addr);
2138 	err = 0;
2139 done:
2140 	return err;
2141 }
2142 EXPORT_SYMBOL(ip_mc_join_group);
2143 
2144 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
2145 			   struct in_device *in_dev)
2146 {
2147 	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
2148 	int err;
2149 
2150 	if (!psf) {
2151 		/* any-source empty exclude case */
2152 		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2153 			iml->sfmode, 0, NULL, 0);
2154 	}
2155 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2156 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
2157 	RCU_INIT_POINTER(iml->sflist, NULL);
2158 	/* decrease mem now to avoid the memleak warning */
2159 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
2160 	kfree_rcu(psf, rcu);
2161 	return err;
2162 }
2163 
2164 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
2165 {
2166 	struct inet_sock *inet = inet_sk(sk);
2167 	struct ip_mc_socklist *iml;
2168 	struct ip_mc_socklist __rcu **imlp;
2169 	struct in_device *in_dev;
2170 	struct net *net = sock_net(sk);
2171 	__be32 group = imr->imr_multiaddr.s_addr;
2172 	u32 ifindex;
2173 	int ret = -EADDRNOTAVAIL;
2174 
2175 	ASSERT_RTNL();
2176 
2177 	in_dev = ip_mc_find_dev(net, imr);
2178 	if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
2179 		ret = -ENODEV;
2180 		goto out;
2181 	}
2182 	ifindex = imr->imr_ifindex;
2183 	for (imlp = &inet->mc_list;
2184 	     (iml = rtnl_dereference(*imlp)) != NULL;
2185 	     imlp = &iml->next_rcu) {
2186 		if (iml->multi.imr_multiaddr.s_addr != group)
2187 			continue;
2188 		if (ifindex) {
2189 			if (iml->multi.imr_ifindex != ifindex)
2190 				continue;
2191 		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
2192 				iml->multi.imr_address.s_addr)
2193 			continue;
2194 
2195 		(void) ip_mc_leave_src(sk, iml, in_dev);
2196 
2197 		*imlp = iml->next_rcu;
2198 
2199 		if (in_dev)
2200 			ip_mc_dec_group(in_dev, group);
2201 
2202 		/* decrease mem now to avoid the memleak warning */
2203 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2204 		kfree_rcu(iml, rcu);
2205 		return 0;
2206 	}
2207 out:
2208 	return ret;
2209 }
2210 EXPORT_SYMBOL(ip_mc_leave_group);
2211 
2212 int ip_mc_source(int add, int omode, struct sock *sk, struct
2213 	ip_mreq_source *mreqs, int ifindex)
2214 {
2215 	int err;
2216 	struct ip_mreqn imr;
2217 	__be32 addr = mreqs->imr_multiaddr;
2218 	struct ip_mc_socklist *pmc;
2219 	struct in_device *in_dev = NULL;
2220 	struct inet_sock *inet = inet_sk(sk);
2221 	struct ip_sf_socklist *psl;
2222 	struct net *net = sock_net(sk);
2223 	int leavegroup = 0;
2224 	int i, j, rv;
2225 
2226 	if (!ipv4_is_multicast(addr))
2227 		return -EINVAL;
2228 
2229 	ASSERT_RTNL();
2230 
2231 	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
2232 	imr.imr_address.s_addr = mreqs->imr_interface;
2233 	imr.imr_ifindex = ifindex;
2234 	in_dev = ip_mc_find_dev(net, &imr);
2235 
2236 	if (!in_dev) {
2237 		err = -ENODEV;
2238 		goto done;
2239 	}
2240 	err = -EADDRNOTAVAIL;
2241 
2242 	for_each_pmc_rtnl(inet, pmc) {
2243 		if ((pmc->multi.imr_multiaddr.s_addr ==
2244 		     imr.imr_multiaddr.s_addr) &&
2245 		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
2246 			break;
2247 	}
2248 	if (!pmc) {		/* must have a prior join */
2249 		err = -EINVAL;
2250 		goto done;
2251 	}
2252 	/* if a source filter was set, must be the same mode as before */
2253 	if (pmc->sflist) {
2254 		if (pmc->sfmode != omode) {
2255 			err = -EINVAL;
2256 			goto done;
2257 		}
2258 	} else if (pmc->sfmode != omode) {
2259 		/* allow mode switches for empty-set filters */
2260 		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2261 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2262 			NULL, 0);
2263 		pmc->sfmode = omode;
2264 	}
2265 
2266 	psl = rtnl_dereference(pmc->sflist);
2267 	if (!add) {
2268 		if (!psl)
2269 			goto done;	/* err = -EADDRNOTAVAIL */
2270 		rv = !0;
2271 		for (i = 0; i < psl->sl_count; i++) {
2272 			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2273 				sizeof(__be32));
2274 			if (rv == 0)
2275 				break;
2276 		}
2277 		if (rv)		/* source not found */
2278 			goto done;	/* err = -EADDRNOTAVAIL */
2279 
2280 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2281 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2282 			leavegroup = 1;
2283 			goto done;
2284 		}
2285 
2286 		/* update the interface filter */
2287 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2288 			&mreqs->imr_sourceaddr, 1);
2289 
2290 		for (j = i+1; j < psl->sl_count; j++)
2291 			psl->sl_addr[j-1] = psl->sl_addr[j];
2292 		psl->sl_count--;
2293 		err = 0;
2294 		goto done;
2295 	}
2296 	/* else, add a new source to the filter */
2297 
2298 	if (psl && psl->sl_count >= net->ipv4.sysctl_igmp_max_msf) {
2299 		err = -ENOBUFS;
2300 		goto done;
2301 	}
2302 	if (!psl || psl->sl_count == psl->sl_max) {
2303 		struct ip_sf_socklist *newpsl;
2304 		int count = IP_SFBLOCK;
2305 
2306 		if (psl)
2307 			count += psl->sl_max;
2308 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2309 		if (!newpsl) {
2310 			err = -ENOBUFS;
2311 			goto done;
2312 		}
2313 		newpsl->sl_max = count;
2314 		newpsl->sl_count = count - IP_SFBLOCK;
2315 		if (psl) {
2316 			for (i = 0; i < psl->sl_count; i++)
2317 				newpsl->sl_addr[i] = psl->sl_addr[i];
2318 			/* decrease mem now to avoid the memleak warning */
2319 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2320 			kfree_rcu(psl, rcu);
2321 		}
2322 		rcu_assign_pointer(pmc->sflist, newpsl);
2323 		psl = newpsl;
2324 	}
2325 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
2326 	for (i = 0; i < psl->sl_count; i++) {
2327 		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2328 			sizeof(__be32));
2329 		if (rv == 0)
2330 			break;
2331 	}
2332 	if (rv == 0)		/* address already there is an error */
2333 		goto done;
2334 	for (j = psl->sl_count-1; j >= i; j--)
2335 		psl->sl_addr[j+1] = psl->sl_addr[j];
2336 	psl->sl_addr[i] = mreqs->imr_sourceaddr;
2337 	psl->sl_count++;
2338 	err = 0;
2339 	/* update the interface list */
2340 	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2341 		&mreqs->imr_sourceaddr, 1);
2342 done:
2343 	if (leavegroup)
2344 		err = ip_mc_leave_group(sk, &imr);
2345 	return err;
2346 }
2347 
2348 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2349 {
2350 	int err = 0;
2351 	struct ip_mreqn	imr;
2352 	__be32 addr = msf->imsf_multiaddr;
2353 	struct ip_mc_socklist *pmc;
2354 	struct in_device *in_dev;
2355 	struct inet_sock *inet = inet_sk(sk);
2356 	struct ip_sf_socklist *newpsl, *psl;
2357 	struct net *net = sock_net(sk);
2358 	int leavegroup = 0;
2359 
2360 	if (!ipv4_is_multicast(addr))
2361 		return -EINVAL;
2362 	if (msf->imsf_fmode != MCAST_INCLUDE &&
2363 	    msf->imsf_fmode != MCAST_EXCLUDE)
2364 		return -EINVAL;
2365 
2366 	ASSERT_RTNL();
2367 
2368 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2369 	imr.imr_address.s_addr = msf->imsf_interface;
2370 	imr.imr_ifindex = ifindex;
2371 	in_dev = ip_mc_find_dev(net, &imr);
2372 
2373 	if (!in_dev) {
2374 		err = -ENODEV;
2375 		goto done;
2376 	}
2377 
2378 	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2379 	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2380 		leavegroup = 1;
2381 		goto done;
2382 	}
2383 
2384 	for_each_pmc_rtnl(inet, pmc) {
2385 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2386 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2387 			break;
2388 	}
2389 	if (!pmc) {		/* must have a prior join */
2390 		err = -EINVAL;
2391 		goto done;
2392 	}
2393 	if (msf->imsf_numsrc) {
2394 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2395 							   GFP_KERNEL);
2396 		if (!newpsl) {
2397 			err = -ENOBUFS;
2398 			goto done;
2399 		}
2400 		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2401 		memcpy(newpsl->sl_addr, msf->imsf_slist,
2402 			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2403 		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2404 			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2405 		if (err) {
2406 			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2407 			goto done;
2408 		}
2409 	} else {
2410 		newpsl = NULL;
2411 		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2412 				     msf->imsf_fmode, 0, NULL, 0);
2413 	}
2414 	psl = rtnl_dereference(pmc->sflist);
2415 	if (psl) {
2416 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2417 			psl->sl_count, psl->sl_addr, 0);
2418 		/* decrease mem now to avoid the memleak warning */
2419 		atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2420 		kfree_rcu(psl, rcu);
2421 	} else
2422 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2423 			0, NULL, 0);
2424 	rcu_assign_pointer(pmc->sflist, newpsl);
2425 	pmc->sfmode = msf->imsf_fmode;
2426 	err = 0;
2427 done:
2428 	if (leavegroup)
2429 		err = ip_mc_leave_group(sk, &imr);
2430 	return err;
2431 }
2432 
2433 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2434 	struct ip_msfilter __user *optval, int __user *optlen)
2435 {
2436 	int err, len, count, copycount;
2437 	struct ip_mreqn	imr;
2438 	__be32 addr = msf->imsf_multiaddr;
2439 	struct ip_mc_socklist *pmc;
2440 	struct in_device *in_dev;
2441 	struct inet_sock *inet = inet_sk(sk);
2442 	struct ip_sf_socklist *psl;
2443 	struct net *net = sock_net(sk);
2444 
2445 	ASSERT_RTNL();
2446 
2447 	if (!ipv4_is_multicast(addr))
2448 		return -EINVAL;
2449 
2450 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2451 	imr.imr_address.s_addr = msf->imsf_interface;
2452 	imr.imr_ifindex = 0;
2453 	in_dev = ip_mc_find_dev(net, &imr);
2454 
2455 	if (!in_dev) {
2456 		err = -ENODEV;
2457 		goto done;
2458 	}
2459 	err = -EADDRNOTAVAIL;
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 		goto done;
2468 	msf->imsf_fmode = pmc->sfmode;
2469 	psl = rtnl_dereference(pmc->sflist);
2470 	if (!psl) {
2471 		len = 0;
2472 		count = 0;
2473 	} else {
2474 		count = psl->sl_count;
2475 	}
2476 	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2477 	len = copycount * sizeof(psl->sl_addr[0]);
2478 	msf->imsf_numsrc = count;
2479 	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2480 	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2481 		return -EFAULT;
2482 	}
2483 	if (len &&
2484 	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2485 		return -EFAULT;
2486 	return 0;
2487 done:
2488 	return err;
2489 }
2490 
2491 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2492 	struct group_filter __user *optval, int __user *optlen)
2493 {
2494 	int err, i, count, copycount;
2495 	struct sockaddr_in *psin;
2496 	__be32 addr;
2497 	struct ip_mc_socklist *pmc;
2498 	struct inet_sock *inet = inet_sk(sk);
2499 	struct ip_sf_socklist *psl;
2500 
2501 	ASSERT_RTNL();
2502 
2503 	psin = (struct sockaddr_in *)&gsf->gf_group;
2504 	if (psin->sin_family != AF_INET)
2505 		return -EINVAL;
2506 	addr = psin->sin_addr.s_addr;
2507 	if (!ipv4_is_multicast(addr))
2508 		return -EINVAL;
2509 
2510 	err = -EADDRNOTAVAIL;
2511 
2512 	for_each_pmc_rtnl(inet, pmc) {
2513 		if (pmc->multi.imr_multiaddr.s_addr == addr &&
2514 		    pmc->multi.imr_ifindex == gsf->gf_interface)
2515 			break;
2516 	}
2517 	if (!pmc)		/* must have a prior join */
2518 		goto done;
2519 	gsf->gf_fmode = pmc->sfmode;
2520 	psl = rtnl_dereference(pmc->sflist);
2521 	count = psl ? psl->sl_count : 0;
2522 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2523 	gsf->gf_numsrc = count;
2524 	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
2525 	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
2526 		return -EFAULT;
2527 	}
2528 	for (i = 0; i < copycount; i++) {
2529 		struct sockaddr_storage ss;
2530 
2531 		psin = (struct sockaddr_in *)&ss;
2532 		memset(&ss, 0, sizeof(ss));
2533 		psin->sin_family = AF_INET;
2534 		psin->sin_addr.s_addr = psl->sl_addr[i];
2535 		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
2536 			return -EFAULT;
2537 	}
2538 	return 0;
2539 done:
2540 	return err;
2541 }
2542 
2543 /*
2544  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2545  */
2546 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
2547 {
2548 	struct inet_sock *inet = inet_sk(sk);
2549 	struct ip_mc_socklist *pmc;
2550 	struct ip_sf_socklist *psl;
2551 	int i;
2552 	int ret;
2553 
2554 	ret = 1;
2555 	if (!ipv4_is_multicast(loc_addr))
2556 		goto out;
2557 
2558 	rcu_read_lock();
2559 	for_each_pmc_rcu(inet, pmc) {
2560 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2561 		    pmc->multi.imr_ifindex == dif)
2562 			break;
2563 	}
2564 	ret = inet->mc_all;
2565 	if (!pmc)
2566 		goto unlock;
2567 	psl = rcu_dereference(pmc->sflist);
2568 	ret = (pmc->sfmode == MCAST_EXCLUDE);
2569 	if (!psl)
2570 		goto unlock;
2571 
2572 	for (i = 0; i < psl->sl_count; i++) {
2573 		if (psl->sl_addr[i] == rmt_addr)
2574 			break;
2575 	}
2576 	ret = 0;
2577 	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2578 		goto unlock;
2579 	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2580 		goto unlock;
2581 	ret = 1;
2582 unlock:
2583 	rcu_read_unlock();
2584 out:
2585 	return ret;
2586 }
2587 
2588 /*
2589  *	A socket is closing.
2590  */
2591 
2592 void ip_mc_drop_socket(struct sock *sk)
2593 {
2594 	struct inet_sock *inet = inet_sk(sk);
2595 	struct ip_mc_socklist *iml;
2596 	struct net *net = sock_net(sk);
2597 
2598 	if (!inet->mc_list)
2599 		return;
2600 
2601 	rtnl_lock();
2602 	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2603 		struct in_device *in_dev;
2604 
2605 		inet->mc_list = iml->next_rcu;
2606 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2607 		(void) ip_mc_leave_src(sk, iml, in_dev);
2608 		if (in_dev)
2609 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2610 		/* decrease mem now to avoid the memleak warning */
2611 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2612 		kfree_rcu(iml, rcu);
2613 	}
2614 	rtnl_unlock();
2615 }
2616 
2617 /* called with rcu_read_lock() */
2618 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
2619 {
2620 	struct ip_mc_list *im;
2621 	struct ip_mc_list __rcu **mc_hash;
2622 	struct ip_sf_list *psf;
2623 	int rv = 0;
2624 
2625 	mc_hash = rcu_dereference(in_dev->mc_hash);
2626 	if (mc_hash) {
2627 		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2628 
2629 		for (im = rcu_dereference(mc_hash[hash]);
2630 		     im != NULL;
2631 		     im = rcu_dereference(im->next_hash)) {
2632 			if (im->multiaddr == mc_addr)
2633 				break;
2634 		}
2635 	} else {
2636 		for_each_pmc_rcu(in_dev, im) {
2637 			if (im->multiaddr == mc_addr)
2638 				break;
2639 		}
2640 	}
2641 	if (im && proto == IPPROTO_IGMP) {
2642 		rv = 1;
2643 	} else if (im) {
2644 		if (src_addr) {
2645 			for (psf = im->sources; psf; psf = psf->sf_next) {
2646 				if (psf->sf_inaddr == src_addr)
2647 					break;
2648 			}
2649 			if (psf)
2650 				rv = psf->sf_count[MCAST_INCLUDE] ||
2651 					psf->sf_count[MCAST_EXCLUDE] !=
2652 					im->sfcount[MCAST_EXCLUDE];
2653 			else
2654 				rv = im->sfcount[MCAST_EXCLUDE] != 0;
2655 		} else
2656 			rv = 1; /* unspecified source; tentatively allow */
2657 	}
2658 	return rv;
2659 }
2660 
2661 #if defined(CONFIG_PROC_FS)
2662 struct igmp_mc_iter_state {
2663 	struct seq_net_private p;
2664 	struct net_device *dev;
2665 	struct in_device *in_dev;
2666 };
2667 
2668 #define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
2669 
2670 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2671 {
2672 	struct net *net = seq_file_net(seq);
2673 	struct ip_mc_list *im = NULL;
2674 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2675 
2676 	state->in_dev = NULL;
2677 	for_each_netdev_rcu(net, state->dev) {
2678 		struct in_device *in_dev;
2679 
2680 		in_dev = __in_dev_get_rcu(state->dev);
2681 		if (!in_dev)
2682 			continue;
2683 		im = rcu_dereference(in_dev->mc_list);
2684 		if (im) {
2685 			state->in_dev = in_dev;
2686 			break;
2687 		}
2688 	}
2689 	return im;
2690 }
2691 
2692 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2693 {
2694 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2695 
2696 	im = rcu_dereference(im->next_rcu);
2697 	while (!im) {
2698 		state->dev = next_net_device_rcu(state->dev);
2699 		if (!state->dev) {
2700 			state->in_dev = NULL;
2701 			break;
2702 		}
2703 		state->in_dev = __in_dev_get_rcu(state->dev);
2704 		if (!state->in_dev)
2705 			continue;
2706 		im = rcu_dereference(state->in_dev->mc_list);
2707 	}
2708 	return im;
2709 }
2710 
2711 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2712 {
2713 	struct ip_mc_list *im = igmp_mc_get_first(seq);
2714 	if (im)
2715 		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2716 			--pos;
2717 	return pos ? NULL : im;
2718 }
2719 
2720 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2721 	__acquires(rcu)
2722 {
2723 	rcu_read_lock();
2724 	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2725 }
2726 
2727 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2728 {
2729 	struct ip_mc_list *im;
2730 	if (v == SEQ_START_TOKEN)
2731 		im = igmp_mc_get_first(seq);
2732 	else
2733 		im = igmp_mc_get_next(seq, v);
2734 	++*pos;
2735 	return im;
2736 }
2737 
2738 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2739 	__releases(rcu)
2740 {
2741 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2742 
2743 	state->in_dev = NULL;
2744 	state->dev = NULL;
2745 	rcu_read_unlock();
2746 }
2747 
2748 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2749 {
2750 	if (v == SEQ_START_TOKEN)
2751 		seq_puts(seq,
2752 			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2753 	else {
2754 		struct ip_mc_list *im = (struct ip_mc_list *)v;
2755 		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2756 		char   *querier;
2757 		long delta;
2758 
2759 #ifdef CONFIG_IP_MULTICAST
2760 		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2761 			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
2762 			  "V3";
2763 #else
2764 		querier = "NONE";
2765 #endif
2766 
2767 		if (rcu_access_pointer(state->in_dev->mc_list) == im) {
2768 			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2769 				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2770 		}
2771 
2772 		delta = im->timer.expires - jiffies;
2773 		seq_printf(seq,
2774 			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2775 			   im->multiaddr, im->users,
2776 			   im->tm_running,
2777 			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2778 			   im->reporter);
2779 	}
2780 	return 0;
2781 }
2782 
2783 static const struct seq_operations igmp_mc_seq_ops = {
2784 	.start	=	igmp_mc_seq_start,
2785 	.next	=	igmp_mc_seq_next,
2786 	.stop	=	igmp_mc_seq_stop,
2787 	.show	=	igmp_mc_seq_show,
2788 };
2789 
2790 static int igmp_mc_seq_open(struct inode *inode, struct file *file)
2791 {
2792 	return seq_open_net(inode, file, &igmp_mc_seq_ops,
2793 			sizeof(struct igmp_mc_iter_state));
2794 }
2795 
2796 static const struct file_operations igmp_mc_seq_fops = {
2797 	.owner		=	THIS_MODULE,
2798 	.open		=	igmp_mc_seq_open,
2799 	.read		=	seq_read,
2800 	.llseek		=	seq_lseek,
2801 	.release	=	seq_release_net,
2802 };
2803 
2804 struct igmp_mcf_iter_state {
2805 	struct seq_net_private p;
2806 	struct net_device *dev;
2807 	struct in_device *idev;
2808 	struct ip_mc_list *im;
2809 };
2810 
2811 #define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
2812 
2813 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2814 {
2815 	struct net *net = seq_file_net(seq);
2816 	struct ip_sf_list *psf = NULL;
2817 	struct ip_mc_list *im = NULL;
2818 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2819 
2820 	state->idev = NULL;
2821 	state->im = NULL;
2822 	for_each_netdev_rcu(net, state->dev) {
2823 		struct in_device *idev;
2824 		idev = __in_dev_get_rcu(state->dev);
2825 		if (unlikely(!idev))
2826 			continue;
2827 		im = rcu_dereference(idev->mc_list);
2828 		if (likely(im)) {
2829 			spin_lock_bh(&im->lock);
2830 			psf = im->sources;
2831 			if (likely(psf)) {
2832 				state->im = im;
2833 				state->idev = idev;
2834 				break;
2835 			}
2836 			spin_unlock_bh(&im->lock);
2837 		}
2838 	}
2839 	return psf;
2840 }
2841 
2842 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2843 {
2844 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2845 
2846 	psf = psf->sf_next;
2847 	while (!psf) {
2848 		spin_unlock_bh(&state->im->lock);
2849 		state->im = state->im->next;
2850 		while (!state->im) {
2851 			state->dev = next_net_device_rcu(state->dev);
2852 			if (!state->dev) {
2853 				state->idev = NULL;
2854 				goto out;
2855 			}
2856 			state->idev = __in_dev_get_rcu(state->dev);
2857 			if (!state->idev)
2858 				continue;
2859 			state->im = rcu_dereference(state->idev->mc_list);
2860 		}
2861 		if (!state->im)
2862 			break;
2863 		spin_lock_bh(&state->im->lock);
2864 		psf = state->im->sources;
2865 	}
2866 out:
2867 	return psf;
2868 }
2869 
2870 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2871 {
2872 	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2873 	if (psf)
2874 		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2875 			--pos;
2876 	return pos ? NULL : psf;
2877 }
2878 
2879 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2880 	__acquires(rcu)
2881 {
2882 	rcu_read_lock();
2883 	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2884 }
2885 
2886 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2887 {
2888 	struct ip_sf_list *psf;
2889 	if (v == SEQ_START_TOKEN)
2890 		psf = igmp_mcf_get_first(seq);
2891 	else
2892 		psf = igmp_mcf_get_next(seq, v);
2893 	++*pos;
2894 	return psf;
2895 }
2896 
2897 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2898 	__releases(rcu)
2899 {
2900 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2901 	if (likely(state->im)) {
2902 		spin_unlock_bh(&state->im->lock);
2903 		state->im = NULL;
2904 	}
2905 	state->idev = NULL;
2906 	state->dev = NULL;
2907 	rcu_read_unlock();
2908 }
2909 
2910 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2911 {
2912 	struct ip_sf_list *psf = (struct ip_sf_list *)v;
2913 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2914 
2915 	if (v == SEQ_START_TOKEN) {
2916 		seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
2917 	} else {
2918 		seq_printf(seq,
2919 			   "%3d %6.6s 0x%08x "
2920 			   "0x%08x %6lu %6lu\n",
2921 			   state->dev->ifindex, state->dev->name,
2922 			   ntohl(state->im->multiaddr),
2923 			   ntohl(psf->sf_inaddr),
2924 			   psf->sf_count[MCAST_INCLUDE],
2925 			   psf->sf_count[MCAST_EXCLUDE]);
2926 	}
2927 	return 0;
2928 }
2929 
2930 static const struct seq_operations igmp_mcf_seq_ops = {
2931 	.start	=	igmp_mcf_seq_start,
2932 	.next	=	igmp_mcf_seq_next,
2933 	.stop	=	igmp_mcf_seq_stop,
2934 	.show	=	igmp_mcf_seq_show,
2935 };
2936 
2937 static int igmp_mcf_seq_open(struct inode *inode, struct file *file)
2938 {
2939 	return seq_open_net(inode, file, &igmp_mcf_seq_ops,
2940 			sizeof(struct igmp_mcf_iter_state));
2941 }
2942 
2943 static const struct file_operations igmp_mcf_seq_fops = {
2944 	.owner		=	THIS_MODULE,
2945 	.open		=	igmp_mcf_seq_open,
2946 	.read		=	seq_read,
2947 	.llseek		=	seq_lseek,
2948 	.release	=	seq_release_net,
2949 };
2950 
2951 static int __net_init igmp_net_init(struct net *net)
2952 {
2953 	struct proc_dir_entry *pde;
2954 	int err;
2955 
2956 	pde = proc_create("igmp", S_IRUGO, net->proc_net, &igmp_mc_seq_fops);
2957 	if (!pde)
2958 		goto out_igmp;
2959 	pde = proc_create("mcfilter", S_IRUGO, net->proc_net,
2960 			  &igmp_mcf_seq_fops);
2961 	if (!pde)
2962 		goto out_mcfilter;
2963 	err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
2964 				   SOCK_DGRAM, 0, net);
2965 	if (err < 0) {
2966 		pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
2967 		       err);
2968 		goto out_sock;
2969 	}
2970 
2971 	/* Sysctl initialization */
2972 	net->ipv4.sysctl_igmp_max_memberships = 20;
2973 	net->ipv4.sysctl_igmp_max_msf = 10;
2974 	/* IGMP reports for link-local multicast groups are enabled by default */
2975 	net->ipv4.sysctl_igmp_llm_reports = 1;
2976 	net->ipv4.sysctl_igmp_qrv = 2;
2977 	return 0;
2978 
2979 out_sock:
2980 	remove_proc_entry("mcfilter", net->proc_net);
2981 out_mcfilter:
2982 	remove_proc_entry("igmp", net->proc_net);
2983 out_igmp:
2984 	return -ENOMEM;
2985 }
2986 
2987 static void __net_exit igmp_net_exit(struct net *net)
2988 {
2989 	remove_proc_entry("mcfilter", net->proc_net);
2990 	remove_proc_entry("igmp", net->proc_net);
2991 	inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
2992 }
2993 
2994 static struct pernet_operations igmp_net_ops = {
2995 	.init = igmp_net_init,
2996 	.exit = igmp_net_exit,
2997 };
2998 #endif
2999 
3000 static int igmp_netdev_event(struct notifier_block *this,
3001 			     unsigned long event, void *ptr)
3002 {
3003 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3004 	struct in_device *in_dev;
3005 
3006 	switch (event) {
3007 	case NETDEV_RESEND_IGMP:
3008 		in_dev = __in_dev_get_rtnl(dev);
3009 		if (in_dev)
3010 			ip_mc_rejoin_groups(in_dev);
3011 		break;
3012 	default:
3013 		break;
3014 	}
3015 	return NOTIFY_DONE;
3016 }
3017 
3018 static struct notifier_block igmp_notifier = {
3019 	.notifier_call = igmp_netdev_event,
3020 };
3021 
3022 int __init igmp_mc_init(void)
3023 {
3024 #if defined(CONFIG_PROC_FS)
3025 	int err;
3026 
3027 	err = register_pernet_subsys(&igmp_net_ops);
3028 	if (err)
3029 		return err;
3030 	err = register_netdevice_notifier(&igmp_notifier);
3031 	if (err)
3032 		goto reg_notif_fail;
3033 	return 0;
3034 
3035 reg_notif_fail:
3036 	unregister_pernet_subsys(&igmp_net_ops);
3037 	return err;
3038 #else
3039 	return register_netdevice_notifier(&igmp_notifier);
3040 #endif
3041 }
3042