xref: /openbmc/linux/net/ipv4/igmp.c (revision d3597236)
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 <asm/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 #define IP_MAX_MEMBERSHIPS	20
111 #define IP_MAX_MSF		10
112 
113 #ifdef CONFIG_IP_MULTICAST
114 /* Parameter names and values are taken from igmp-v2-06 draft */
115 
116 #define IGMP_V1_ROUTER_PRESENT_TIMEOUT		(400*HZ)
117 #define IGMP_V2_ROUTER_PRESENT_TIMEOUT		(400*HZ)
118 #define IGMP_V2_UNSOLICITED_REPORT_INTERVAL	(10*HZ)
119 #define IGMP_V3_UNSOLICITED_REPORT_INTERVAL	(1*HZ)
120 #define IGMP_QUERY_RESPONSE_INTERVAL		(10*HZ)
121 #define IGMP_QUERY_ROBUSTNESS_VARIABLE		2
122 
123 
124 #define IGMP_INITIAL_REPORT_DELAY		(1)
125 
126 /* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
127  * IGMP specs require to report membership immediately after
128  * joining a group, but we delay the first report by a
129  * small interval. It seems more natural and still does not
130  * contradict to specs provided this delay is small enough.
131  */
132 
133 #define IGMP_V1_SEEN(in_dev) \
134 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
135 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
136 	 ((in_dev)->mr_v1_seen && \
137 	  time_before(jiffies, (in_dev)->mr_v1_seen)))
138 #define IGMP_V2_SEEN(in_dev) \
139 	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
140 	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
141 	 ((in_dev)->mr_v2_seen && \
142 	  time_before(jiffies, (in_dev)->mr_v2_seen)))
143 
144 static int unsolicited_report_interval(struct in_device *in_dev)
145 {
146 	int interval_ms, interval_jiffies;
147 
148 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
149 		interval_ms = IN_DEV_CONF_GET(
150 			in_dev,
151 			IGMPV2_UNSOLICITED_REPORT_INTERVAL);
152 	else /* v3 */
153 		interval_ms = IN_DEV_CONF_GET(
154 			in_dev,
155 			IGMPV3_UNSOLICITED_REPORT_INTERVAL);
156 
157 	interval_jiffies = msecs_to_jiffies(interval_ms);
158 
159 	/* _timer functions can't handle a delay of 0 jiffies so ensure
160 	 *  we always return a positive value.
161 	 */
162 	if (interval_jiffies <= 0)
163 		interval_jiffies = 1;
164 	return interval_jiffies;
165 }
166 
167 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
168 static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr);
169 static void igmpv3_clear_delrec(struct in_device *in_dev);
170 static int sf_setstate(struct ip_mc_list *pmc);
171 static void sf_markstate(struct ip_mc_list *pmc);
172 #endif
173 static void ip_mc_clear_src(struct ip_mc_list *pmc);
174 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
175 			 int sfcount, __be32 *psfsrc, int delta);
176 
177 static void ip_ma_put(struct ip_mc_list *im)
178 {
179 	if (atomic_dec_and_test(&im->refcnt)) {
180 		in_dev_put(im->interface);
181 		kfree_rcu(im, rcu);
182 	}
183 }
184 
185 #define for_each_pmc_rcu(in_dev, pmc)				\
186 	for (pmc = rcu_dereference(in_dev->mc_list);		\
187 	     pmc != NULL;					\
188 	     pmc = rcu_dereference(pmc->next_rcu))
189 
190 #define for_each_pmc_rtnl(in_dev, pmc)				\
191 	for (pmc = rtnl_dereference(in_dev->mc_list);		\
192 	     pmc != NULL;					\
193 	     pmc = rtnl_dereference(pmc->next_rcu))
194 
195 #ifdef CONFIG_IP_MULTICAST
196 
197 /*
198  *	Timer management
199  */
200 
201 static void igmp_stop_timer(struct ip_mc_list *im)
202 {
203 	spin_lock_bh(&im->lock);
204 	if (del_timer(&im->timer))
205 		atomic_dec(&im->refcnt);
206 	im->tm_running = 0;
207 	im->reporter = 0;
208 	im->unsolicit_count = 0;
209 	spin_unlock_bh(&im->lock);
210 }
211 
212 /* It must be called with locked im->lock */
213 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
214 {
215 	int tv = prandom_u32() % max_delay;
216 
217 	im->tm_running = 1;
218 	if (!mod_timer(&im->timer, jiffies+tv+2))
219 		atomic_inc(&im->refcnt);
220 }
221 
222 static void igmp_gq_start_timer(struct in_device *in_dev)
223 {
224 	int tv = prandom_u32() % in_dev->mr_maxdelay;
225 
226 	in_dev->mr_gq_running = 1;
227 	if (!mod_timer(&in_dev->mr_gq_timer, jiffies+tv+2))
228 		in_dev_hold(in_dev);
229 }
230 
231 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
232 {
233 	int tv = prandom_u32() % delay;
234 
235 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
236 		in_dev_hold(in_dev);
237 }
238 
239 static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
240 {
241 	spin_lock_bh(&im->lock);
242 	im->unsolicit_count = 0;
243 	if (del_timer(&im->timer)) {
244 		if ((long)(im->timer.expires-jiffies) < max_delay) {
245 			add_timer(&im->timer);
246 			im->tm_running = 1;
247 			spin_unlock_bh(&im->lock);
248 			return;
249 		}
250 		atomic_dec(&im->refcnt);
251 	}
252 	igmp_start_timer(im, max_delay);
253 	spin_unlock_bh(&im->lock);
254 }
255 
256 
257 /*
258  *	Send an IGMP report.
259  */
260 
261 #define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
262 
263 
264 static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
265 	int gdeleted, int sdeleted)
266 {
267 	switch (type) {
268 	case IGMPV3_MODE_IS_INCLUDE:
269 	case IGMPV3_MODE_IS_EXCLUDE:
270 		if (gdeleted || sdeleted)
271 			return 0;
272 		if (!(pmc->gsquery && !psf->sf_gsresp)) {
273 			if (pmc->sfmode == MCAST_INCLUDE)
274 				return 1;
275 			/* don't include if this source is excluded
276 			 * in all filters
277 			 */
278 			if (psf->sf_count[MCAST_INCLUDE])
279 				return type == IGMPV3_MODE_IS_INCLUDE;
280 			return pmc->sfcount[MCAST_EXCLUDE] ==
281 				psf->sf_count[MCAST_EXCLUDE];
282 		}
283 		return 0;
284 	case IGMPV3_CHANGE_TO_INCLUDE:
285 		if (gdeleted || sdeleted)
286 			return 0;
287 		return psf->sf_count[MCAST_INCLUDE] != 0;
288 	case IGMPV3_CHANGE_TO_EXCLUDE:
289 		if (gdeleted || sdeleted)
290 			return 0;
291 		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
292 		    psf->sf_count[MCAST_INCLUDE])
293 			return 0;
294 		return pmc->sfcount[MCAST_EXCLUDE] ==
295 			psf->sf_count[MCAST_EXCLUDE];
296 	case IGMPV3_ALLOW_NEW_SOURCES:
297 		if (gdeleted || !psf->sf_crcount)
298 			return 0;
299 		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
300 	case IGMPV3_BLOCK_OLD_SOURCES:
301 		if (pmc->sfmode == MCAST_INCLUDE)
302 			return gdeleted || (psf->sf_crcount && sdeleted);
303 		return psf->sf_crcount && !gdeleted && !sdeleted;
304 	}
305 	return 0;
306 }
307 
308 static int
309 igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
310 {
311 	struct ip_sf_list *psf;
312 	int scount = 0;
313 
314 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
315 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
316 			continue;
317 		scount++;
318 	}
319 	return scount;
320 }
321 
322 static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
323 {
324 	struct sk_buff *skb;
325 	struct rtable *rt;
326 	struct iphdr *pip;
327 	struct igmpv3_report *pig;
328 	struct net *net = dev_net(dev);
329 	struct flowi4 fl4;
330 	int hlen = LL_RESERVED_SPACE(dev);
331 	int tlen = dev->needed_tailroom;
332 	unsigned int size = mtu;
333 
334 	while (1) {
335 		skb = alloc_skb(size + hlen + tlen,
336 				GFP_ATOMIC | __GFP_NOWARN);
337 		if (skb)
338 			break;
339 		size >>= 1;
340 		if (size < 256)
341 			return NULL;
342 	}
343 	skb->priority = TC_PRIO_CONTROL;
344 
345 	rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
346 				   0, 0,
347 				   IPPROTO_IGMP, 0, dev->ifindex);
348 	if (IS_ERR(rt)) {
349 		kfree_skb(skb);
350 		return NULL;
351 	}
352 
353 	skb_dst_set(skb, &rt->dst);
354 	skb->dev = dev;
355 
356 	skb->reserved_tailroom = skb_end_offset(skb) -
357 				 min(mtu, skb_end_offset(skb));
358 	skb_reserve(skb, hlen);
359 
360 	skb_reset_network_header(skb);
361 	pip = ip_hdr(skb);
362 	skb_put(skb, sizeof(struct iphdr) + 4);
363 
364 	pip->version  = 4;
365 	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
366 	pip->tos      = 0xc0;
367 	pip->frag_off = htons(IP_DF);
368 	pip->ttl      = 1;
369 	pip->daddr    = fl4.daddr;
370 	pip->saddr    = fl4.saddr;
371 	pip->protocol = IPPROTO_IGMP;
372 	pip->tot_len  = 0;	/* filled in later */
373 	ip_select_ident(net, skb, NULL);
374 	((u8 *)&pip[1])[0] = IPOPT_RA;
375 	((u8 *)&pip[1])[1] = 4;
376 	((u8 *)&pip[1])[2] = 0;
377 	((u8 *)&pip[1])[3] = 0;
378 
379 	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
380 	skb_put(skb, sizeof(*pig));
381 	pig = igmpv3_report_hdr(skb);
382 	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
383 	pig->resv1 = 0;
384 	pig->csum = 0;
385 	pig->resv2 = 0;
386 	pig->ngrec = 0;
387 	return skb;
388 }
389 
390 static int igmpv3_sendpack(struct sk_buff *skb)
391 {
392 	struct igmphdr *pig = igmp_hdr(skb);
393 	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
394 
395 	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
396 
397 	return ip_local_out(skb);
398 }
399 
400 static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
401 {
402 	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
403 }
404 
405 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
406 	int type, struct igmpv3_grec **ppgr)
407 {
408 	struct net_device *dev = pmc->interface->dev;
409 	struct igmpv3_report *pih;
410 	struct igmpv3_grec *pgr;
411 
412 	if (!skb)
413 		skb = igmpv3_newpack(dev, dev->mtu);
414 	if (!skb)
415 		return NULL;
416 	pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
417 	pgr->grec_type = type;
418 	pgr->grec_auxwords = 0;
419 	pgr->grec_nsrcs = 0;
420 	pgr->grec_mca = pmc->multiaddr;
421 	pih = igmpv3_report_hdr(skb);
422 	pih->ngrec = htons(ntohs(pih->ngrec)+1);
423 	*ppgr = pgr;
424 	return skb;
425 }
426 
427 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
428 
429 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
430 	int type, int gdeleted, int sdeleted)
431 {
432 	struct net_device *dev = pmc->interface->dev;
433 	struct igmpv3_report *pih;
434 	struct igmpv3_grec *pgr = NULL;
435 	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
436 	int scount, stotal, first, isquery, truncate;
437 
438 	if (pmc->multiaddr == IGMP_ALL_HOSTS)
439 		return skb;
440 
441 	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
442 		  type == IGMPV3_MODE_IS_EXCLUDE;
443 	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
444 		    type == IGMPV3_CHANGE_TO_EXCLUDE;
445 
446 	stotal = scount = 0;
447 
448 	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
449 
450 	if (!*psf_list)
451 		goto empty_source;
452 
453 	pih = skb ? igmpv3_report_hdr(skb) : NULL;
454 
455 	/* EX and TO_EX get a fresh packet, if needed */
456 	if (truncate) {
457 		if (pih && pih->ngrec &&
458 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
459 			if (skb)
460 				igmpv3_sendpack(skb);
461 			skb = igmpv3_newpack(dev, dev->mtu);
462 		}
463 	}
464 	first = 1;
465 	psf_prev = NULL;
466 	for (psf = *psf_list; psf; psf = psf_next) {
467 		__be32 *psrc;
468 
469 		psf_next = psf->sf_next;
470 
471 		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
472 			psf_prev = psf;
473 			continue;
474 		}
475 
476 		/* clear marks on query responses */
477 		if (isquery)
478 			psf->sf_gsresp = 0;
479 
480 		if (AVAILABLE(skb) < sizeof(__be32) +
481 		    first*sizeof(struct igmpv3_grec)) {
482 			if (truncate && !first)
483 				break;	 /* truncate these */
484 			if (pgr)
485 				pgr->grec_nsrcs = htons(scount);
486 			if (skb)
487 				igmpv3_sendpack(skb);
488 			skb = igmpv3_newpack(dev, dev->mtu);
489 			first = 1;
490 			scount = 0;
491 		}
492 		if (first) {
493 			skb = add_grhead(skb, pmc, type, &pgr);
494 			first = 0;
495 		}
496 		if (!skb)
497 			return NULL;
498 		psrc = (__be32 *)skb_put(skb, sizeof(__be32));
499 		*psrc = psf->sf_inaddr;
500 		scount++; stotal++;
501 		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
502 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
503 			psf->sf_crcount--;
504 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
505 				if (psf_prev)
506 					psf_prev->sf_next = psf->sf_next;
507 				else
508 					*psf_list = psf->sf_next;
509 				kfree(psf);
510 				continue;
511 			}
512 		}
513 		psf_prev = psf;
514 	}
515 
516 empty_source:
517 	if (!stotal) {
518 		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
519 		    type == IGMPV3_BLOCK_OLD_SOURCES)
520 			return skb;
521 		if (pmc->crcount || isquery) {
522 			/* make sure we have room for group header */
523 			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
524 				igmpv3_sendpack(skb);
525 				skb = NULL; /* add_grhead will get a new one */
526 			}
527 			skb = add_grhead(skb, pmc, type, &pgr);
528 		}
529 	}
530 	if (pgr)
531 		pgr->grec_nsrcs = htons(scount);
532 
533 	if (isquery)
534 		pmc->gsquery = 0;	/* clear query state on report */
535 	return skb;
536 }
537 
538 static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
539 {
540 	struct sk_buff *skb = NULL;
541 	int type;
542 
543 	if (!pmc) {
544 		rcu_read_lock();
545 		for_each_pmc_rcu(in_dev, pmc) {
546 			if (pmc->multiaddr == IGMP_ALL_HOSTS)
547 				continue;
548 			spin_lock_bh(&pmc->lock);
549 			if (pmc->sfcount[MCAST_EXCLUDE])
550 				type = IGMPV3_MODE_IS_EXCLUDE;
551 			else
552 				type = IGMPV3_MODE_IS_INCLUDE;
553 			skb = add_grec(skb, pmc, type, 0, 0);
554 			spin_unlock_bh(&pmc->lock);
555 		}
556 		rcu_read_unlock();
557 	} else {
558 		spin_lock_bh(&pmc->lock);
559 		if (pmc->sfcount[MCAST_EXCLUDE])
560 			type = IGMPV3_MODE_IS_EXCLUDE;
561 		else
562 			type = IGMPV3_MODE_IS_INCLUDE;
563 		skb = add_grec(skb, pmc, type, 0, 0);
564 		spin_unlock_bh(&pmc->lock);
565 	}
566 	if (!skb)
567 		return 0;
568 	return igmpv3_sendpack(skb);
569 }
570 
571 /*
572  * remove zero-count source records from a source filter list
573  */
574 static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
575 {
576 	struct ip_sf_list *psf_prev, *psf_next, *psf;
577 
578 	psf_prev = NULL;
579 	for (psf = *ppsf; psf; psf = psf_next) {
580 		psf_next = psf->sf_next;
581 		if (psf->sf_crcount == 0) {
582 			if (psf_prev)
583 				psf_prev->sf_next = psf->sf_next;
584 			else
585 				*ppsf = psf->sf_next;
586 			kfree(psf);
587 		} else
588 			psf_prev = psf;
589 	}
590 }
591 
592 static void igmpv3_send_cr(struct in_device *in_dev)
593 {
594 	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
595 	struct sk_buff *skb = NULL;
596 	int type, dtype;
597 
598 	rcu_read_lock();
599 	spin_lock_bh(&in_dev->mc_tomb_lock);
600 
601 	/* deleted MCA's */
602 	pmc_prev = NULL;
603 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
604 		pmc_next = pmc->next;
605 		if (pmc->sfmode == MCAST_INCLUDE) {
606 			type = IGMPV3_BLOCK_OLD_SOURCES;
607 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
608 			skb = add_grec(skb, pmc, type, 1, 0);
609 			skb = add_grec(skb, pmc, dtype, 1, 1);
610 		}
611 		if (pmc->crcount) {
612 			if (pmc->sfmode == MCAST_EXCLUDE) {
613 				type = IGMPV3_CHANGE_TO_INCLUDE;
614 				skb = add_grec(skb, pmc, type, 1, 0);
615 			}
616 			pmc->crcount--;
617 			if (pmc->crcount == 0) {
618 				igmpv3_clear_zeros(&pmc->tomb);
619 				igmpv3_clear_zeros(&pmc->sources);
620 			}
621 		}
622 		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
623 			if (pmc_prev)
624 				pmc_prev->next = pmc_next;
625 			else
626 				in_dev->mc_tomb = pmc_next;
627 			in_dev_put(pmc->interface);
628 			kfree(pmc);
629 		} else
630 			pmc_prev = pmc;
631 	}
632 	spin_unlock_bh(&in_dev->mc_tomb_lock);
633 
634 	/* change recs */
635 	for_each_pmc_rcu(in_dev, pmc) {
636 		spin_lock_bh(&pmc->lock);
637 		if (pmc->sfcount[MCAST_EXCLUDE]) {
638 			type = IGMPV3_BLOCK_OLD_SOURCES;
639 			dtype = IGMPV3_ALLOW_NEW_SOURCES;
640 		} else {
641 			type = IGMPV3_ALLOW_NEW_SOURCES;
642 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
643 		}
644 		skb = add_grec(skb, pmc, type, 0, 0);
645 		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
646 
647 		/* filter mode changes */
648 		if (pmc->crcount) {
649 			if (pmc->sfmode == MCAST_EXCLUDE)
650 				type = IGMPV3_CHANGE_TO_EXCLUDE;
651 			else
652 				type = IGMPV3_CHANGE_TO_INCLUDE;
653 			skb = add_grec(skb, pmc, type, 0, 0);
654 			pmc->crcount--;
655 		}
656 		spin_unlock_bh(&pmc->lock);
657 	}
658 	rcu_read_unlock();
659 
660 	if (!skb)
661 		return;
662 	(void) igmpv3_sendpack(skb);
663 }
664 
665 static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
666 	int type)
667 {
668 	struct sk_buff *skb;
669 	struct iphdr *iph;
670 	struct igmphdr *ih;
671 	struct rtable *rt;
672 	struct net_device *dev = in_dev->dev;
673 	struct net *net = dev_net(dev);
674 	__be32	group = pmc ? pmc->multiaddr : 0;
675 	struct flowi4 fl4;
676 	__be32	dst;
677 	int hlen, tlen;
678 
679 	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
680 		return igmpv3_send_report(in_dev, pmc);
681 	else if (type == IGMP_HOST_LEAVE_MESSAGE)
682 		dst = IGMP_ALL_ROUTER;
683 	else
684 		dst = group;
685 
686 	rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
687 				   0, 0,
688 				   IPPROTO_IGMP, 0, dev->ifindex);
689 	if (IS_ERR(rt))
690 		return -1;
691 
692 	hlen = LL_RESERVED_SPACE(dev);
693 	tlen = dev->needed_tailroom;
694 	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
695 	if (!skb) {
696 		ip_rt_put(rt);
697 		return -1;
698 	}
699 	skb->priority = TC_PRIO_CONTROL;
700 
701 	skb_dst_set(skb, &rt->dst);
702 
703 	skb_reserve(skb, hlen);
704 
705 	skb_reset_network_header(skb);
706 	iph = ip_hdr(skb);
707 	skb_put(skb, sizeof(struct iphdr) + 4);
708 
709 	iph->version  = 4;
710 	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
711 	iph->tos      = 0xc0;
712 	iph->frag_off = htons(IP_DF);
713 	iph->ttl      = 1;
714 	iph->daddr    = dst;
715 	iph->saddr    = fl4.saddr;
716 	iph->protocol = IPPROTO_IGMP;
717 	ip_select_ident(net, skb, NULL);
718 	((u8 *)&iph[1])[0] = IPOPT_RA;
719 	((u8 *)&iph[1])[1] = 4;
720 	((u8 *)&iph[1])[2] = 0;
721 	((u8 *)&iph[1])[3] = 0;
722 
723 	ih = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
724 	ih->type = type;
725 	ih->code = 0;
726 	ih->csum = 0;
727 	ih->group = group;
728 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
729 
730 	return ip_local_out(skb);
731 }
732 
733 static void igmp_gq_timer_expire(unsigned long data)
734 {
735 	struct in_device *in_dev = (struct in_device *)data;
736 
737 	in_dev->mr_gq_running = 0;
738 	igmpv3_send_report(in_dev, NULL);
739 	in_dev_put(in_dev);
740 }
741 
742 static void igmp_ifc_timer_expire(unsigned long data)
743 {
744 	struct in_device *in_dev = (struct in_device *)data;
745 
746 	igmpv3_send_cr(in_dev);
747 	if (in_dev->mr_ifc_count) {
748 		in_dev->mr_ifc_count--;
749 		igmp_ifc_start_timer(in_dev,
750 				     unsolicited_report_interval(in_dev));
751 	}
752 	in_dev_put(in_dev);
753 }
754 
755 static void igmp_ifc_event(struct in_device *in_dev)
756 {
757 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
758 		return;
759 	in_dev->mr_ifc_count = in_dev->mr_qrv ?: sysctl_igmp_qrv;
760 	igmp_ifc_start_timer(in_dev, 1);
761 }
762 
763 
764 static void igmp_timer_expire(unsigned long data)
765 {
766 	struct ip_mc_list *im = (struct ip_mc_list *)data;
767 	struct in_device *in_dev = im->interface;
768 
769 	spin_lock(&im->lock);
770 	im->tm_running = 0;
771 
772 	if (im->unsolicit_count) {
773 		im->unsolicit_count--;
774 		igmp_start_timer(im, unsolicited_report_interval(in_dev));
775 	}
776 	im->reporter = 1;
777 	spin_unlock(&im->lock);
778 
779 	if (IGMP_V1_SEEN(in_dev))
780 		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
781 	else if (IGMP_V2_SEEN(in_dev))
782 		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
783 	else
784 		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
785 
786 	ip_ma_put(im);
787 }
788 
789 /* mark EXCLUDE-mode sources */
790 static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
791 {
792 	struct ip_sf_list *psf;
793 	int i, scount;
794 
795 	scount = 0;
796 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
797 		if (scount == nsrcs)
798 			break;
799 		for (i = 0; i < nsrcs; i++) {
800 			/* skip inactive filters */
801 			if (psf->sf_count[MCAST_INCLUDE] ||
802 			    pmc->sfcount[MCAST_EXCLUDE] !=
803 			    psf->sf_count[MCAST_EXCLUDE])
804 				break;
805 			if (srcs[i] == psf->sf_inaddr) {
806 				scount++;
807 				break;
808 			}
809 		}
810 	}
811 	pmc->gsquery = 0;
812 	if (scount == nsrcs)	/* all sources excluded */
813 		return 0;
814 	return 1;
815 }
816 
817 static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
818 {
819 	struct ip_sf_list *psf;
820 	int i, scount;
821 
822 	if (pmc->sfmode == MCAST_EXCLUDE)
823 		return igmp_xmarksources(pmc, nsrcs, srcs);
824 
825 	/* mark INCLUDE-mode sources */
826 	scount = 0;
827 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
828 		if (scount == nsrcs)
829 			break;
830 		for (i = 0; i < nsrcs; i++)
831 			if (srcs[i] == psf->sf_inaddr) {
832 				psf->sf_gsresp = 1;
833 				scount++;
834 				break;
835 			}
836 	}
837 	if (!scount) {
838 		pmc->gsquery = 0;
839 		return 0;
840 	}
841 	pmc->gsquery = 1;
842 	return 1;
843 }
844 
845 /* return true if packet was dropped */
846 static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
847 {
848 	struct ip_mc_list *im;
849 
850 	/* Timers are only set for non-local groups */
851 
852 	if (group == IGMP_ALL_HOSTS)
853 		return false;
854 
855 	rcu_read_lock();
856 	for_each_pmc_rcu(in_dev, im) {
857 		if (im->multiaddr == group) {
858 			igmp_stop_timer(im);
859 			break;
860 		}
861 	}
862 	rcu_read_unlock();
863 	return false;
864 }
865 
866 /* return true if packet was dropped */
867 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
868 	int len)
869 {
870 	struct igmphdr 		*ih = igmp_hdr(skb);
871 	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
872 	struct ip_mc_list	*im;
873 	__be32			group = ih->group;
874 	int			max_delay;
875 	int			mark = 0;
876 
877 
878 	if (len == 8) {
879 		if (ih->code == 0) {
880 			/* Alas, old v1 router presents here. */
881 
882 			max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
883 			in_dev->mr_v1_seen = jiffies +
884 				IGMP_V1_ROUTER_PRESENT_TIMEOUT;
885 			group = 0;
886 		} else {
887 			/* v2 router present */
888 			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
889 			in_dev->mr_v2_seen = jiffies +
890 				IGMP_V2_ROUTER_PRESENT_TIMEOUT;
891 		}
892 		/* cancel the interface change timer */
893 		in_dev->mr_ifc_count = 0;
894 		if (del_timer(&in_dev->mr_ifc_timer))
895 			__in_dev_put(in_dev);
896 		/* clear deleted report items */
897 		igmpv3_clear_delrec(in_dev);
898 	} else if (len < 12) {
899 		return true;	/* ignore bogus packet; freed by caller */
900 	} else if (IGMP_V1_SEEN(in_dev)) {
901 		/* This is a v3 query with v1 queriers present */
902 		max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
903 		group = 0;
904 	} else if (IGMP_V2_SEEN(in_dev)) {
905 		/* this is a v3 query with v2 queriers present;
906 		 * Interpretation of the max_delay code is problematic here.
907 		 * A real v2 host would use ih_code directly, while v3 has a
908 		 * different encoding. We use the v3 encoding as more likely
909 		 * to be intended in a v3 query.
910 		 */
911 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
912 		if (!max_delay)
913 			max_delay = 1;	/* can't mod w/ 0 */
914 	} else { /* v3 */
915 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
916 			return true;
917 
918 		ih3 = igmpv3_query_hdr(skb);
919 		if (ih3->nsrcs) {
920 			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
921 					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
922 				return true;
923 			ih3 = igmpv3_query_hdr(skb);
924 		}
925 
926 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
927 		if (!max_delay)
928 			max_delay = 1;	/* can't mod w/ 0 */
929 		in_dev->mr_maxdelay = max_delay;
930 		if (ih3->qrv)
931 			in_dev->mr_qrv = ih3->qrv;
932 		if (!group) { /* general query */
933 			if (ih3->nsrcs)
934 				return true;	/* no sources allowed */
935 			igmp_gq_start_timer(in_dev);
936 			return false;
937 		}
938 		/* mark sources to include, if group & source-specific */
939 		mark = ih3->nsrcs != 0;
940 	}
941 
942 	/*
943 	 * - Start the timers in all of our membership records
944 	 *   that the query applies to for the interface on
945 	 *   which the query arrived excl. those that belong
946 	 *   to a "local" group (224.0.0.X)
947 	 * - For timers already running check if they need to
948 	 *   be reset.
949 	 * - Use the igmp->igmp_code field as the maximum
950 	 *   delay possible
951 	 */
952 	rcu_read_lock();
953 	for_each_pmc_rcu(in_dev, im) {
954 		int changed;
955 
956 		if (group && group != im->multiaddr)
957 			continue;
958 		if (im->multiaddr == IGMP_ALL_HOSTS)
959 			continue;
960 		spin_lock_bh(&im->lock);
961 		if (im->tm_running)
962 			im->gsquery = im->gsquery && mark;
963 		else
964 			im->gsquery = mark;
965 		changed = !im->gsquery ||
966 			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
967 		spin_unlock_bh(&im->lock);
968 		if (changed)
969 			igmp_mod_timer(im, max_delay);
970 	}
971 	rcu_read_unlock();
972 	return false;
973 }
974 
975 /* called in rcu_read_lock() section */
976 int igmp_rcv(struct sk_buff *skb)
977 {
978 	/* This basically follows the spec line by line -- see RFC1112 */
979 	struct igmphdr *ih;
980 	struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
981 	int len = skb->len;
982 	bool dropped = true;
983 
984 	if (!in_dev)
985 		goto drop;
986 
987 	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
988 		goto drop;
989 
990 	if (skb_checksum_simple_validate(skb))
991 		goto drop;
992 
993 	ih = igmp_hdr(skb);
994 	switch (ih->type) {
995 	case IGMP_HOST_MEMBERSHIP_QUERY:
996 		dropped = igmp_heard_query(in_dev, skb, len);
997 		break;
998 	case IGMP_HOST_MEMBERSHIP_REPORT:
999 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1000 		/* Is it our report looped back? */
1001 		if (rt_is_output_route(skb_rtable(skb)))
1002 			break;
1003 		/* don't rely on MC router hearing unicast reports */
1004 		if (skb->pkt_type == PACKET_MULTICAST ||
1005 		    skb->pkt_type == PACKET_BROADCAST)
1006 			dropped = igmp_heard_report(in_dev, ih->group);
1007 		break;
1008 	case IGMP_PIM:
1009 #ifdef CONFIG_IP_PIMSM_V1
1010 		return pim_rcv_v1(skb);
1011 #endif
1012 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1013 	case IGMP_DVMRP:
1014 	case IGMP_TRACE:
1015 	case IGMP_HOST_LEAVE_MESSAGE:
1016 	case IGMP_MTRACE:
1017 	case IGMP_MTRACE_RESP:
1018 		break;
1019 	default:
1020 		break;
1021 	}
1022 
1023 drop:
1024 	if (dropped)
1025 		kfree_skb(skb);
1026 	else
1027 		consume_skb(skb);
1028 	return 0;
1029 }
1030 
1031 #endif
1032 
1033 
1034 /*
1035  *	Add a filter to a device
1036  */
1037 
1038 static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
1039 {
1040 	char buf[MAX_ADDR_LEN];
1041 	struct net_device *dev = in_dev->dev;
1042 
1043 	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
1044 	   We will get multicast token leakage, when IFF_MULTICAST
1045 	   is changed. This check should be done in ndo_set_rx_mode
1046 	   routine. Something sort of:
1047 	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
1048 	   --ANK
1049 	   */
1050 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1051 		dev_mc_add(dev, buf);
1052 }
1053 
1054 /*
1055  *	Remove a filter from a device
1056  */
1057 
1058 static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
1059 {
1060 	char buf[MAX_ADDR_LEN];
1061 	struct net_device *dev = in_dev->dev;
1062 
1063 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1064 		dev_mc_del(dev, buf);
1065 }
1066 
1067 #ifdef CONFIG_IP_MULTICAST
1068 /*
1069  * deleted ip_mc_list manipulation
1070  */
1071 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1072 {
1073 	struct ip_mc_list *pmc;
1074 
1075 	/* this is an "ip_mc_list" for convenience; only the fields below
1076 	 * are actually used. In particular, the refcnt and users are not
1077 	 * used for management of the delete list. Using the same structure
1078 	 * for deleted items allows change reports to use common code with
1079 	 * non-deleted or query-response MCA's.
1080 	 */
1081 	pmc = kzalloc(sizeof(*pmc), GFP_KERNEL);
1082 	if (!pmc)
1083 		return;
1084 	spin_lock_bh(&im->lock);
1085 	pmc->interface = im->interface;
1086 	in_dev_hold(in_dev);
1087 	pmc->multiaddr = im->multiaddr;
1088 	pmc->crcount = in_dev->mr_qrv ?: sysctl_igmp_qrv;
1089 	pmc->sfmode = im->sfmode;
1090 	if (pmc->sfmode == MCAST_INCLUDE) {
1091 		struct ip_sf_list *psf;
1092 
1093 		pmc->tomb = im->tomb;
1094 		pmc->sources = im->sources;
1095 		im->tomb = im->sources = NULL;
1096 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1097 			psf->sf_crcount = pmc->crcount;
1098 	}
1099 	spin_unlock_bh(&im->lock);
1100 
1101 	spin_lock_bh(&in_dev->mc_tomb_lock);
1102 	pmc->next = in_dev->mc_tomb;
1103 	in_dev->mc_tomb = pmc;
1104 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1105 }
1106 
1107 static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr)
1108 {
1109 	struct ip_mc_list *pmc, *pmc_prev;
1110 	struct ip_sf_list *psf, *psf_next;
1111 
1112 	spin_lock_bh(&in_dev->mc_tomb_lock);
1113 	pmc_prev = NULL;
1114 	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
1115 		if (pmc->multiaddr == multiaddr)
1116 			break;
1117 		pmc_prev = pmc;
1118 	}
1119 	if (pmc) {
1120 		if (pmc_prev)
1121 			pmc_prev->next = pmc->next;
1122 		else
1123 			in_dev->mc_tomb = pmc->next;
1124 	}
1125 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1126 	if (pmc) {
1127 		for (psf = pmc->tomb; psf; psf = psf_next) {
1128 			psf_next = psf->sf_next;
1129 			kfree(psf);
1130 		}
1131 		in_dev_put(pmc->interface);
1132 		kfree(pmc);
1133 	}
1134 }
1135 
1136 static void igmpv3_clear_delrec(struct in_device *in_dev)
1137 {
1138 	struct ip_mc_list *pmc, *nextpmc;
1139 
1140 	spin_lock_bh(&in_dev->mc_tomb_lock);
1141 	pmc = in_dev->mc_tomb;
1142 	in_dev->mc_tomb = NULL;
1143 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1144 
1145 	for (; pmc; pmc = nextpmc) {
1146 		nextpmc = pmc->next;
1147 		ip_mc_clear_src(pmc);
1148 		in_dev_put(pmc->interface);
1149 		kfree(pmc);
1150 	}
1151 	/* clear dead sources, too */
1152 	rcu_read_lock();
1153 	for_each_pmc_rcu(in_dev, pmc) {
1154 		struct ip_sf_list *psf, *psf_next;
1155 
1156 		spin_lock_bh(&pmc->lock);
1157 		psf = pmc->tomb;
1158 		pmc->tomb = NULL;
1159 		spin_unlock_bh(&pmc->lock);
1160 		for (; psf; psf = psf_next) {
1161 			psf_next = psf->sf_next;
1162 			kfree(psf);
1163 		}
1164 	}
1165 	rcu_read_unlock();
1166 }
1167 #endif
1168 
1169 static void igmp_group_dropped(struct ip_mc_list *im)
1170 {
1171 	struct in_device *in_dev = im->interface;
1172 #ifdef CONFIG_IP_MULTICAST
1173 	int reporter;
1174 #endif
1175 
1176 	if (im->loaded) {
1177 		im->loaded = 0;
1178 		ip_mc_filter_del(in_dev, im->multiaddr);
1179 	}
1180 
1181 #ifdef CONFIG_IP_MULTICAST
1182 	if (im->multiaddr == IGMP_ALL_HOSTS)
1183 		return;
1184 
1185 	reporter = im->reporter;
1186 	igmp_stop_timer(im);
1187 
1188 	if (!in_dev->dead) {
1189 		if (IGMP_V1_SEEN(in_dev))
1190 			return;
1191 		if (IGMP_V2_SEEN(in_dev)) {
1192 			if (reporter)
1193 				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
1194 			return;
1195 		}
1196 		/* IGMPv3 */
1197 		igmpv3_add_delrec(in_dev, im);
1198 
1199 		igmp_ifc_event(in_dev);
1200 	}
1201 #endif
1202 }
1203 
1204 static void igmp_group_added(struct ip_mc_list *im)
1205 {
1206 	struct in_device *in_dev = im->interface;
1207 
1208 	if (im->loaded == 0) {
1209 		im->loaded = 1;
1210 		ip_mc_filter_add(in_dev, im->multiaddr);
1211 	}
1212 
1213 #ifdef CONFIG_IP_MULTICAST
1214 	if (im->multiaddr == IGMP_ALL_HOSTS)
1215 		return;
1216 
1217 	if (in_dev->dead)
1218 		return;
1219 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
1220 		spin_lock_bh(&im->lock);
1221 		igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
1222 		spin_unlock_bh(&im->lock);
1223 		return;
1224 	}
1225 	/* else, v3 */
1226 
1227 	im->crcount = in_dev->mr_qrv ?: sysctl_igmp_qrv;
1228 	igmp_ifc_event(in_dev);
1229 #endif
1230 }
1231 
1232 
1233 /*
1234  *	Multicast list managers
1235  */
1236 
1237 static u32 ip_mc_hash(const struct ip_mc_list *im)
1238 {
1239 	return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
1240 }
1241 
1242 static void ip_mc_hash_add(struct in_device *in_dev,
1243 			   struct ip_mc_list *im)
1244 {
1245 	struct ip_mc_list __rcu **mc_hash;
1246 	u32 hash;
1247 
1248 	mc_hash = rtnl_dereference(in_dev->mc_hash);
1249 	if (mc_hash) {
1250 		hash = ip_mc_hash(im);
1251 		im->next_hash = mc_hash[hash];
1252 		rcu_assign_pointer(mc_hash[hash], im);
1253 		return;
1254 	}
1255 
1256 	/* do not use a hash table for small number of items */
1257 	if (in_dev->mc_count < 4)
1258 		return;
1259 
1260 	mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
1261 			  GFP_KERNEL);
1262 	if (!mc_hash)
1263 		return;
1264 
1265 	for_each_pmc_rtnl(in_dev, im) {
1266 		hash = ip_mc_hash(im);
1267 		im->next_hash = mc_hash[hash];
1268 		RCU_INIT_POINTER(mc_hash[hash], im);
1269 	}
1270 
1271 	rcu_assign_pointer(in_dev->mc_hash, mc_hash);
1272 }
1273 
1274 static void ip_mc_hash_remove(struct in_device *in_dev,
1275 			      struct ip_mc_list *im)
1276 {
1277 	struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
1278 	struct ip_mc_list *aux;
1279 
1280 	if (!mc_hash)
1281 		return;
1282 	mc_hash += ip_mc_hash(im);
1283 	while ((aux = rtnl_dereference(*mc_hash)) != im)
1284 		mc_hash = &aux->next_hash;
1285 	*mc_hash = im->next_hash;
1286 }
1287 
1288 
1289 /*
1290  *	A socket has joined a multicast group on device dev.
1291  */
1292 
1293 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
1294 {
1295 	struct ip_mc_list *im;
1296 
1297 	ASSERT_RTNL();
1298 
1299 	for_each_pmc_rtnl(in_dev, im) {
1300 		if (im->multiaddr == addr) {
1301 			im->users++;
1302 			ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, NULL, 0);
1303 			goto out;
1304 		}
1305 	}
1306 
1307 	im = kzalloc(sizeof(*im), GFP_KERNEL);
1308 	if (!im)
1309 		goto out;
1310 
1311 	im->users = 1;
1312 	im->interface = in_dev;
1313 	in_dev_hold(in_dev);
1314 	im->multiaddr = addr;
1315 	/* initial mode is (EX, empty) */
1316 	im->sfmode = MCAST_EXCLUDE;
1317 	im->sfcount[MCAST_EXCLUDE] = 1;
1318 	atomic_set(&im->refcnt, 1);
1319 	spin_lock_init(&im->lock);
1320 #ifdef CONFIG_IP_MULTICAST
1321 	setup_timer(&im->timer, igmp_timer_expire, (unsigned long)im);
1322 	im->unsolicit_count = sysctl_igmp_qrv;
1323 #endif
1324 
1325 	im->next_rcu = in_dev->mc_list;
1326 	in_dev->mc_count++;
1327 	rcu_assign_pointer(in_dev->mc_list, im);
1328 
1329 	ip_mc_hash_add(in_dev, im);
1330 
1331 #ifdef CONFIG_IP_MULTICAST
1332 	igmpv3_del_delrec(in_dev, im->multiaddr);
1333 #endif
1334 	igmp_group_added(im);
1335 	if (!in_dev->dead)
1336 		ip_rt_multicast_event(in_dev);
1337 out:
1338 	return;
1339 }
1340 EXPORT_SYMBOL(ip_mc_inc_group);
1341 
1342 static int ip_mc_check_iphdr(struct sk_buff *skb)
1343 {
1344 	const struct iphdr *iph;
1345 	unsigned int len;
1346 	unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
1347 
1348 	if (!pskb_may_pull(skb, offset))
1349 		return -EINVAL;
1350 
1351 	iph = ip_hdr(skb);
1352 
1353 	if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
1354 		return -EINVAL;
1355 
1356 	offset += ip_hdrlen(skb) - sizeof(*iph);
1357 
1358 	if (!pskb_may_pull(skb, offset))
1359 		return -EINVAL;
1360 
1361 	iph = ip_hdr(skb);
1362 
1363 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1364 		return -EINVAL;
1365 
1366 	len = skb_network_offset(skb) + ntohs(iph->tot_len);
1367 	if (skb->len < len || len < offset)
1368 		return -EINVAL;
1369 
1370 	skb_set_transport_header(skb, offset);
1371 
1372 	return 0;
1373 }
1374 
1375 static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
1376 {
1377 	unsigned int len = skb_transport_offset(skb);
1378 
1379 	len += sizeof(struct igmpv3_report);
1380 
1381 	return pskb_may_pull(skb, len) ? 0 : -EINVAL;
1382 }
1383 
1384 static int ip_mc_check_igmp_query(struct sk_buff *skb)
1385 {
1386 	unsigned int len = skb_transport_offset(skb);
1387 
1388 	len += sizeof(struct igmphdr);
1389 	if (skb->len < len)
1390 		return -EINVAL;
1391 
1392 	/* IGMPv{1,2}? */
1393 	if (skb->len != len) {
1394 		/* or IGMPv3? */
1395 		len += sizeof(struct igmpv3_query) - sizeof(struct igmphdr);
1396 		if (skb->len < len || !pskb_may_pull(skb, len))
1397 			return -EINVAL;
1398 	}
1399 
1400 	/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
1401 	 * all-systems destination addresses (224.0.0.1) for general queries
1402 	 */
1403 	if (!igmp_hdr(skb)->group &&
1404 	    ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
1405 		return -EINVAL;
1406 
1407 	return 0;
1408 }
1409 
1410 static int ip_mc_check_igmp_msg(struct sk_buff *skb)
1411 {
1412 	switch (igmp_hdr(skb)->type) {
1413 	case IGMP_HOST_LEAVE_MESSAGE:
1414 	case IGMP_HOST_MEMBERSHIP_REPORT:
1415 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1416 		/* fall through */
1417 		return 0;
1418 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1419 		return ip_mc_check_igmp_reportv3(skb);
1420 	case IGMP_HOST_MEMBERSHIP_QUERY:
1421 		return ip_mc_check_igmp_query(skb);
1422 	default:
1423 		return -ENOMSG;
1424 	}
1425 }
1426 
1427 static inline __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
1428 {
1429 	return skb_checksum_simple_validate(skb);
1430 }
1431 
1432 static int __ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
1433 
1434 {
1435 	struct sk_buff *skb_chk;
1436 	unsigned int transport_len;
1437 	unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
1438 	int ret;
1439 
1440 	transport_len = ntohs(ip_hdr(skb)->tot_len) - ip_hdrlen(skb);
1441 
1442 	skb_get(skb);
1443 	skb_chk = skb_checksum_trimmed(skb, transport_len,
1444 				       ip_mc_validate_checksum);
1445 	if (!skb_chk)
1446 		return -EINVAL;
1447 
1448 	if (!pskb_may_pull(skb_chk, len)) {
1449 		kfree_skb(skb_chk);
1450 		return -EINVAL;
1451 	}
1452 
1453 	ret = ip_mc_check_igmp_msg(skb_chk);
1454 	if (ret) {
1455 		kfree_skb(skb_chk);
1456 		return ret;
1457 	}
1458 
1459 	if (skb_trimmed)
1460 		*skb_trimmed = skb_chk;
1461 	else
1462 		kfree_skb(skb_chk);
1463 
1464 	return 0;
1465 }
1466 
1467 /**
1468  * ip_mc_check_igmp - checks whether this is a sane IGMP packet
1469  * @skb: the skb to validate
1470  * @skb_trimmed: to store an skb pointer trimmed to IPv4 packet tail (optional)
1471  *
1472  * Checks whether an IPv4 packet is a valid IGMP packet. If so sets
1473  * skb network and transport headers accordingly and returns zero.
1474  *
1475  * -EINVAL: A broken packet was detected, i.e. it violates some internet
1476  *  standard
1477  * -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
1478  * -ENOMEM: A memory allocation failure happened.
1479  *
1480  * Optionally, an skb pointer might be provided via skb_trimmed (or set it
1481  * to NULL): After parsing an IGMP packet successfully it will point to
1482  * an skb which has its tail aligned to the IP packet end. This might
1483  * either be the originally provided skb or a trimmed, cloned version if
1484  * the skb frame had data beyond the IP packet. A cloned skb allows us
1485  * to leave the original skb and its full frame unchanged (which might be
1486  * desirable for layer 2 frame jugglers).
1487  *
1488  * The caller needs to release a reference count from any returned skb_trimmed.
1489  */
1490 int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
1491 {
1492 	int ret = ip_mc_check_iphdr(skb);
1493 
1494 	if (ret < 0)
1495 		return ret;
1496 
1497 	if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
1498 		return -ENOMSG;
1499 
1500 	return __ip_mc_check_igmp(skb, skb_trimmed);
1501 }
1502 EXPORT_SYMBOL(ip_mc_check_igmp);
1503 
1504 /*
1505  *	Resend IGMP JOIN report; used by netdev notifier.
1506  */
1507 static void ip_mc_rejoin_groups(struct in_device *in_dev)
1508 {
1509 #ifdef CONFIG_IP_MULTICAST
1510 	struct ip_mc_list *im;
1511 	int type;
1512 
1513 	ASSERT_RTNL();
1514 
1515 	for_each_pmc_rtnl(in_dev, im) {
1516 		if (im->multiaddr == IGMP_ALL_HOSTS)
1517 			continue;
1518 
1519 		/* a failover is happening and switches
1520 		 * must be notified immediately
1521 		 */
1522 		if (IGMP_V1_SEEN(in_dev))
1523 			type = IGMP_HOST_MEMBERSHIP_REPORT;
1524 		else if (IGMP_V2_SEEN(in_dev))
1525 			type = IGMPV2_HOST_MEMBERSHIP_REPORT;
1526 		else
1527 			type = IGMPV3_HOST_MEMBERSHIP_REPORT;
1528 		igmp_send_report(in_dev, im, type);
1529 	}
1530 #endif
1531 }
1532 
1533 /*
1534  *	A socket has left a multicast group on device dev
1535  */
1536 
1537 void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
1538 {
1539 	struct ip_mc_list *i;
1540 	struct ip_mc_list __rcu **ip;
1541 
1542 	ASSERT_RTNL();
1543 
1544 	for (ip = &in_dev->mc_list;
1545 	     (i = rtnl_dereference(*ip)) != NULL;
1546 	     ip = &i->next_rcu) {
1547 		if (i->multiaddr == addr) {
1548 			if (--i->users == 0) {
1549 				ip_mc_hash_remove(in_dev, i);
1550 				*ip = i->next_rcu;
1551 				in_dev->mc_count--;
1552 				igmp_group_dropped(i);
1553 				ip_mc_clear_src(i);
1554 
1555 				if (!in_dev->dead)
1556 					ip_rt_multicast_event(in_dev);
1557 
1558 				ip_ma_put(i);
1559 				return;
1560 			}
1561 			break;
1562 		}
1563 	}
1564 }
1565 EXPORT_SYMBOL(ip_mc_dec_group);
1566 
1567 /* Device changing type */
1568 
1569 void ip_mc_unmap(struct in_device *in_dev)
1570 {
1571 	struct ip_mc_list *pmc;
1572 
1573 	ASSERT_RTNL();
1574 
1575 	for_each_pmc_rtnl(in_dev, pmc)
1576 		igmp_group_dropped(pmc);
1577 }
1578 
1579 void ip_mc_remap(struct in_device *in_dev)
1580 {
1581 	struct ip_mc_list *pmc;
1582 
1583 	ASSERT_RTNL();
1584 
1585 	for_each_pmc_rtnl(in_dev, pmc)
1586 		igmp_group_added(pmc);
1587 }
1588 
1589 /* Device going down */
1590 
1591 void ip_mc_down(struct in_device *in_dev)
1592 {
1593 	struct ip_mc_list *pmc;
1594 
1595 	ASSERT_RTNL();
1596 
1597 	for_each_pmc_rtnl(in_dev, pmc)
1598 		igmp_group_dropped(pmc);
1599 
1600 #ifdef CONFIG_IP_MULTICAST
1601 	in_dev->mr_ifc_count = 0;
1602 	if (del_timer(&in_dev->mr_ifc_timer))
1603 		__in_dev_put(in_dev);
1604 	in_dev->mr_gq_running = 0;
1605 	if (del_timer(&in_dev->mr_gq_timer))
1606 		__in_dev_put(in_dev);
1607 	igmpv3_clear_delrec(in_dev);
1608 #endif
1609 
1610 	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
1611 }
1612 
1613 void ip_mc_init_dev(struct in_device *in_dev)
1614 {
1615 	ASSERT_RTNL();
1616 
1617 #ifdef CONFIG_IP_MULTICAST
1618 	setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
1619 			(unsigned long)in_dev);
1620 	setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
1621 			(unsigned long)in_dev);
1622 	in_dev->mr_qrv = sysctl_igmp_qrv;
1623 #endif
1624 
1625 	spin_lock_init(&in_dev->mc_tomb_lock);
1626 }
1627 
1628 /* Device going up */
1629 
1630 void ip_mc_up(struct in_device *in_dev)
1631 {
1632 	struct ip_mc_list *pmc;
1633 
1634 	ASSERT_RTNL();
1635 
1636 #ifdef CONFIG_IP_MULTICAST
1637 	in_dev->mr_qrv = sysctl_igmp_qrv;
1638 #endif
1639 	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
1640 
1641 	for_each_pmc_rtnl(in_dev, pmc)
1642 		igmp_group_added(pmc);
1643 }
1644 
1645 /*
1646  *	Device is about to be destroyed: clean up.
1647  */
1648 
1649 void ip_mc_destroy_dev(struct in_device *in_dev)
1650 {
1651 	struct ip_mc_list *i;
1652 
1653 	ASSERT_RTNL();
1654 
1655 	/* Deactivate timers */
1656 	ip_mc_down(in_dev);
1657 
1658 	while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
1659 		in_dev->mc_list = i->next_rcu;
1660 		in_dev->mc_count--;
1661 
1662 		/* We've dropped the groups in ip_mc_down already */
1663 		ip_mc_clear_src(i);
1664 		ip_ma_put(i);
1665 	}
1666 }
1667 
1668 /* RTNL is locked */
1669 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1670 {
1671 	struct net_device *dev = NULL;
1672 	struct in_device *idev = NULL;
1673 
1674 	if (imr->imr_ifindex) {
1675 		idev = inetdev_by_index(net, imr->imr_ifindex);
1676 		return idev;
1677 	}
1678 	if (imr->imr_address.s_addr) {
1679 		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1680 		if (!dev)
1681 			return NULL;
1682 	}
1683 
1684 	if (!dev) {
1685 		struct rtable *rt = ip_route_output(net,
1686 						    imr->imr_multiaddr.s_addr,
1687 						    0, 0, 0);
1688 		if (!IS_ERR(rt)) {
1689 			dev = rt->dst.dev;
1690 			ip_rt_put(rt);
1691 		}
1692 	}
1693 	if (dev) {
1694 		imr->imr_ifindex = dev->ifindex;
1695 		idev = __in_dev_get_rtnl(dev);
1696 	}
1697 	return idev;
1698 }
1699 
1700 /*
1701  *	Join a socket to a group
1702  */
1703 int sysctl_igmp_max_memberships __read_mostly = IP_MAX_MEMBERSHIPS;
1704 int sysctl_igmp_max_msf __read_mostly = IP_MAX_MSF;
1705 #ifdef CONFIG_IP_MULTICAST
1706 int sysctl_igmp_qrv __read_mostly = IGMP_QUERY_ROBUSTNESS_VARIABLE;
1707 #endif
1708 
1709 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1710 	__be32 *psfsrc)
1711 {
1712 	struct ip_sf_list *psf, *psf_prev;
1713 	int rv = 0;
1714 
1715 	psf_prev = NULL;
1716 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1717 		if (psf->sf_inaddr == *psfsrc)
1718 			break;
1719 		psf_prev = psf;
1720 	}
1721 	if (!psf || psf->sf_count[sfmode] == 0) {
1722 		/* source filter not found, or count wrong =>  bug */
1723 		return -ESRCH;
1724 	}
1725 	psf->sf_count[sfmode]--;
1726 	if (psf->sf_count[sfmode] == 0) {
1727 		ip_rt_multicast_event(pmc->interface);
1728 	}
1729 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1730 #ifdef CONFIG_IP_MULTICAST
1731 		struct in_device *in_dev = pmc->interface;
1732 #endif
1733 
1734 		/* no more filters for this source */
1735 		if (psf_prev)
1736 			psf_prev->sf_next = psf->sf_next;
1737 		else
1738 			pmc->sources = psf->sf_next;
1739 #ifdef CONFIG_IP_MULTICAST
1740 		if (psf->sf_oldin &&
1741 		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1742 			psf->sf_crcount = in_dev->mr_qrv ?: sysctl_igmp_qrv;
1743 			psf->sf_next = pmc->tomb;
1744 			pmc->tomb = psf;
1745 			rv = 1;
1746 		} else
1747 #endif
1748 			kfree(psf);
1749 	}
1750 	return rv;
1751 }
1752 
1753 #ifndef CONFIG_IP_MULTICAST
1754 #define igmp_ifc_event(x)	do { } while (0)
1755 #endif
1756 
1757 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1758 			 int sfcount, __be32 *psfsrc, int delta)
1759 {
1760 	struct ip_mc_list *pmc;
1761 	int	changerec = 0;
1762 	int	i, err;
1763 
1764 	if (!in_dev)
1765 		return -ENODEV;
1766 	rcu_read_lock();
1767 	for_each_pmc_rcu(in_dev, pmc) {
1768 		if (*pmca == pmc->multiaddr)
1769 			break;
1770 	}
1771 	if (!pmc) {
1772 		/* MCA not found?? bug */
1773 		rcu_read_unlock();
1774 		return -ESRCH;
1775 	}
1776 	spin_lock_bh(&pmc->lock);
1777 	rcu_read_unlock();
1778 #ifdef CONFIG_IP_MULTICAST
1779 	sf_markstate(pmc);
1780 #endif
1781 	if (!delta) {
1782 		err = -EINVAL;
1783 		if (!pmc->sfcount[sfmode])
1784 			goto out_unlock;
1785 		pmc->sfcount[sfmode]--;
1786 	}
1787 	err = 0;
1788 	for (i = 0; i < sfcount; i++) {
1789 		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1790 
1791 		changerec |= rv > 0;
1792 		if (!err && rv < 0)
1793 			err = rv;
1794 	}
1795 	if (pmc->sfmode == MCAST_EXCLUDE &&
1796 	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1797 	    pmc->sfcount[MCAST_INCLUDE]) {
1798 #ifdef CONFIG_IP_MULTICAST
1799 		struct ip_sf_list *psf;
1800 #endif
1801 
1802 		/* filter mode change */
1803 		pmc->sfmode = MCAST_INCLUDE;
1804 #ifdef CONFIG_IP_MULTICAST
1805 		pmc->crcount = in_dev->mr_qrv ?: sysctl_igmp_qrv;
1806 		in_dev->mr_ifc_count = pmc->crcount;
1807 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1808 			psf->sf_crcount = 0;
1809 		igmp_ifc_event(pmc->interface);
1810 	} else if (sf_setstate(pmc) || changerec) {
1811 		igmp_ifc_event(pmc->interface);
1812 #endif
1813 	}
1814 out_unlock:
1815 	spin_unlock_bh(&pmc->lock);
1816 	return err;
1817 }
1818 
1819 /*
1820  * Add multicast single-source filter to the interface list
1821  */
1822 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1823 	__be32 *psfsrc)
1824 {
1825 	struct ip_sf_list *psf, *psf_prev;
1826 
1827 	psf_prev = NULL;
1828 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1829 		if (psf->sf_inaddr == *psfsrc)
1830 			break;
1831 		psf_prev = psf;
1832 	}
1833 	if (!psf) {
1834 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1835 		if (!psf)
1836 			return -ENOBUFS;
1837 		psf->sf_inaddr = *psfsrc;
1838 		if (psf_prev) {
1839 			psf_prev->sf_next = psf;
1840 		} else
1841 			pmc->sources = psf;
1842 	}
1843 	psf->sf_count[sfmode]++;
1844 	if (psf->sf_count[sfmode] == 1) {
1845 		ip_rt_multicast_event(pmc->interface);
1846 	}
1847 	return 0;
1848 }
1849 
1850 #ifdef CONFIG_IP_MULTICAST
1851 static void sf_markstate(struct ip_mc_list *pmc)
1852 {
1853 	struct ip_sf_list *psf;
1854 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1855 
1856 	for (psf = pmc->sources; psf; psf = psf->sf_next)
1857 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1858 			psf->sf_oldin = mca_xcount ==
1859 				psf->sf_count[MCAST_EXCLUDE] &&
1860 				!psf->sf_count[MCAST_INCLUDE];
1861 		} else
1862 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
1863 }
1864 
1865 static int sf_setstate(struct ip_mc_list *pmc)
1866 {
1867 	struct ip_sf_list *psf, *dpsf;
1868 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1869 	int qrv = pmc->interface->mr_qrv;
1870 	int new_in, rv;
1871 
1872 	rv = 0;
1873 	for (psf = pmc->sources; psf; psf = psf->sf_next) {
1874 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1875 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
1876 				!psf->sf_count[MCAST_INCLUDE];
1877 		} else
1878 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
1879 		if (new_in) {
1880 			if (!psf->sf_oldin) {
1881 				struct ip_sf_list *prev = NULL;
1882 
1883 				for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
1884 					if (dpsf->sf_inaddr == psf->sf_inaddr)
1885 						break;
1886 					prev = dpsf;
1887 				}
1888 				if (dpsf) {
1889 					if (prev)
1890 						prev->sf_next = dpsf->sf_next;
1891 					else
1892 						pmc->tomb = dpsf->sf_next;
1893 					kfree(dpsf);
1894 				}
1895 				psf->sf_crcount = qrv;
1896 				rv++;
1897 			}
1898 		} else if (psf->sf_oldin) {
1899 
1900 			psf->sf_crcount = 0;
1901 			/*
1902 			 * add or update "delete" records if an active filter
1903 			 * is now inactive
1904 			 */
1905 			for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
1906 				if (dpsf->sf_inaddr == psf->sf_inaddr)
1907 					break;
1908 			if (!dpsf) {
1909 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
1910 				if (!dpsf)
1911 					continue;
1912 				*dpsf = *psf;
1913 				/* pmc->lock held by callers */
1914 				dpsf->sf_next = pmc->tomb;
1915 				pmc->tomb = dpsf;
1916 			}
1917 			dpsf->sf_crcount = qrv;
1918 			rv++;
1919 		}
1920 	}
1921 	return rv;
1922 }
1923 #endif
1924 
1925 /*
1926  * Add multicast source filter list to the interface list
1927  */
1928 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1929 			 int sfcount, __be32 *psfsrc, int delta)
1930 {
1931 	struct ip_mc_list *pmc;
1932 	int	isexclude;
1933 	int	i, err;
1934 
1935 	if (!in_dev)
1936 		return -ENODEV;
1937 	rcu_read_lock();
1938 	for_each_pmc_rcu(in_dev, pmc) {
1939 		if (*pmca == pmc->multiaddr)
1940 			break;
1941 	}
1942 	if (!pmc) {
1943 		/* MCA not found?? bug */
1944 		rcu_read_unlock();
1945 		return -ESRCH;
1946 	}
1947 	spin_lock_bh(&pmc->lock);
1948 	rcu_read_unlock();
1949 
1950 #ifdef CONFIG_IP_MULTICAST
1951 	sf_markstate(pmc);
1952 #endif
1953 	isexclude = pmc->sfmode == MCAST_EXCLUDE;
1954 	if (!delta)
1955 		pmc->sfcount[sfmode]++;
1956 	err = 0;
1957 	for (i = 0; i < sfcount; i++) {
1958 		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
1959 		if (err)
1960 			break;
1961 	}
1962 	if (err) {
1963 		int j;
1964 
1965 		if (!delta)
1966 			pmc->sfcount[sfmode]--;
1967 		for (j = 0; j < i; j++)
1968 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
1969 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
1970 #ifdef CONFIG_IP_MULTICAST
1971 		struct ip_sf_list *psf;
1972 		in_dev = pmc->interface;
1973 #endif
1974 
1975 		/* filter mode change */
1976 		if (pmc->sfcount[MCAST_EXCLUDE])
1977 			pmc->sfmode = MCAST_EXCLUDE;
1978 		else if (pmc->sfcount[MCAST_INCLUDE])
1979 			pmc->sfmode = MCAST_INCLUDE;
1980 #ifdef CONFIG_IP_MULTICAST
1981 		/* else no filters; keep old mode for reports */
1982 
1983 		pmc->crcount = in_dev->mr_qrv ?: sysctl_igmp_qrv;
1984 		in_dev->mr_ifc_count = pmc->crcount;
1985 		for (psf = pmc->sources; psf; psf = psf->sf_next)
1986 			psf->sf_crcount = 0;
1987 		igmp_ifc_event(in_dev);
1988 	} else if (sf_setstate(pmc)) {
1989 		igmp_ifc_event(in_dev);
1990 #endif
1991 	}
1992 	spin_unlock_bh(&pmc->lock);
1993 	return err;
1994 }
1995 
1996 static void ip_mc_clear_src(struct ip_mc_list *pmc)
1997 {
1998 	struct ip_sf_list *psf, *nextpsf;
1999 
2000 	for (psf = pmc->tomb; psf; psf = nextpsf) {
2001 		nextpsf = psf->sf_next;
2002 		kfree(psf);
2003 	}
2004 	pmc->tomb = NULL;
2005 	for (psf = pmc->sources; psf; psf = nextpsf) {
2006 		nextpsf = psf->sf_next;
2007 		kfree(psf);
2008 	}
2009 	pmc->sources = NULL;
2010 	pmc->sfmode = MCAST_EXCLUDE;
2011 	pmc->sfcount[MCAST_INCLUDE] = 0;
2012 	pmc->sfcount[MCAST_EXCLUDE] = 1;
2013 }
2014 
2015 /* Join a multicast group
2016  */
2017 
2018 int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
2019 {
2020 	__be32 addr = imr->imr_multiaddr.s_addr;
2021 	struct ip_mc_socklist *iml, *i;
2022 	struct in_device *in_dev;
2023 	struct inet_sock *inet = inet_sk(sk);
2024 	struct net *net = sock_net(sk);
2025 	int ifindex;
2026 	int count = 0;
2027 	int err;
2028 
2029 	ASSERT_RTNL();
2030 
2031 	if (!ipv4_is_multicast(addr))
2032 		return -EINVAL;
2033 
2034 	in_dev = ip_mc_find_dev(net, imr);
2035 
2036 	if (!in_dev) {
2037 		err = -ENODEV;
2038 		goto done;
2039 	}
2040 
2041 	err = -EADDRINUSE;
2042 	ifindex = imr->imr_ifindex;
2043 	for_each_pmc_rtnl(inet, i) {
2044 		if (i->multi.imr_multiaddr.s_addr == addr &&
2045 		    i->multi.imr_ifindex == ifindex)
2046 			goto done;
2047 		count++;
2048 	}
2049 	err = -ENOBUFS;
2050 	if (count >= sysctl_igmp_max_memberships)
2051 		goto done;
2052 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
2053 	if (!iml)
2054 		goto done;
2055 
2056 	memcpy(&iml->multi, imr, sizeof(*imr));
2057 	iml->next_rcu = inet->mc_list;
2058 	iml->sflist = NULL;
2059 	iml->sfmode = MCAST_EXCLUDE;
2060 	rcu_assign_pointer(inet->mc_list, iml);
2061 	ip_mc_inc_group(in_dev, addr);
2062 	err = 0;
2063 done:
2064 	return err;
2065 }
2066 EXPORT_SYMBOL(ip_mc_join_group);
2067 
2068 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
2069 			   struct in_device *in_dev)
2070 {
2071 	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
2072 	int err;
2073 
2074 	if (!psf) {
2075 		/* any-source empty exclude case */
2076 		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2077 			iml->sfmode, 0, NULL, 0);
2078 	}
2079 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2080 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
2081 	RCU_INIT_POINTER(iml->sflist, NULL);
2082 	/* decrease mem now to avoid the memleak warning */
2083 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
2084 	kfree_rcu(psf, rcu);
2085 	return err;
2086 }
2087 
2088 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
2089 {
2090 	struct inet_sock *inet = inet_sk(sk);
2091 	struct ip_mc_socklist *iml;
2092 	struct ip_mc_socklist __rcu **imlp;
2093 	struct in_device *in_dev;
2094 	struct net *net = sock_net(sk);
2095 	__be32 group = imr->imr_multiaddr.s_addr;
2096 	u32 ifindex;
2097 	int ret = -EADDRNOTAVAIL;
2098 
2099 	ASSERT_RTNL();
2100 
2101 	in_dev = ip_mc_find_dev(net, imr);
2102 	if (!in_dev) {
2103 		ret = -ENODEV;
2104 		goto out;
2105 	}
2106 	ifindex = imr->imr_ifindex;
2107 	for (imlp = &inet->mc_list;
2108 	     (iml = rtnl_dereference(*imlp)) != NULL;
2109 	     imlp = &iml->next_rcu) {
2110 		if (iml->multi.imr_multiaddr.s_addr != group)
2111 			continue;
2112 		if (ifindex) {
2113 			if (iml->multi.imr_ifindex != ifindex)
2114 				continue;
2115 		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
2116 				iml->multi.imr_address.s_addr)
2117 			continue;
2118 
2119 		(void) ip_mc_leave_src(sk, iml, in_dev);
2120 
2121 		*imlp = iml->next_rcu;
2122 
2123 		ip_mc_dec_group(in_dev, group);
2124 
2125 		/* decrease mem now to avoid the memleak warning */
2126 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2127 		kfree_rcu(iml, rcu);
2128 		return 0;
2129 	}
2130 out:
2131 	return ret;
2132 }
2133 EXPORT_SYMBOL(ip_mc_leave_group);
2134 
2135 int ip_mc_source(int add, int omode, struct sock *sk, struct
2136 	ip_mreq_source *mreqs, int ifindex)
2137 {
2138 	int err;
2139 	struct ip_mreqn imr;
2140 	__be32 addr = mreqs->imr_multiaddr;
2141 	struct ip_mc_socklist *pmc;
2142 	struct in_device *in_dev = NULL;
2143 	struct inet_sock *inet = inet_sk(sk);
2144 	struct ip_sf_socklist *psl;
2145 	struct net *net = sock_net(sk);
2146 	int leavegroup = 0;
2147 	int i, j, rv;
2148 
2149 	if (!ipv4_is_multicast(addr))
2150 		return -EINVAL;
2151 
2152 	ASSERT_RTNL();
2153 
2154 	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
2155 	imr.imr_address.s_addr = mreqs->imr_interface;
2156 	imr.imr_ifindex = ifindex;
2157 	in_dev = ip_mc_find_dev(net, &imr);
2158 
2159 	if (!in_dev) {
2160 		err = -ENODEV;
2161 		goto done;
2162 	}
2163 	err = -EADDRNOTAVAIL;
2164 
2165 	for_each_pmc_rtnl(inet, pmc) {
2166 		if ((pmc->multi.imr_multiaddr.s_addr ==
2167 		     imr.imr_multiaddr.s_addr) &&
2168 		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
2169 			break;
2170 	}
2171 	if (!pmc) {		/* must have a prior join */
2172 		err = -EINVAL;
2173 		goto done;
2174 	}
2175 	/* if a source filter was set, must be the same mode as before */
2176 	if (pmc->sflist) {
2177 		if (pmc->sfmode != omode) {
2178 			err = -EINVAL;
2179 			goto done;
2180 		}
2181 	} else if (pmc->sfmode != omode) {
2182 		/* allow mode switches for empty-set filters */
2183 		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2184 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2185 			NULL, 0);
2186 		pmc->sfmode = omode;
2187 	}
2188 
2189 	psl = rtnl_dereference(pmc->sflist);
2190 	if (!add) {
2191 		if (!psl)
2192 			goto done;	/* err = -EADDRNOTAVAIL */
2193 		rv = !0;
2194 		for (i = 0; i < psl->sl_count; i++) {
2195 			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2196 				sizeof(__be32));
2197 			if (rv == 0)
2198 				break;
2199 		}
2200 		if (rv)		/* source not found */
2201 			goto done;	/* err = -EADDRNOTAVAIL */
2202 
2203 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2204 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2205 			leavegroup = 1;
2206 			goto done;
2207 		}
2208 
2209 		/* update the interface filter */
2210 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2211 			&mreqs->imr_sourceaddr, 1);
2212 
2213 		for (j = i+1; j < psl->sl_count; j++)
2214 			psl->sl_addr[j-1] = psl->sl_addr[j];
2215 		psl->sl_count--;
2216 		err = 0;
2217 		goto done;
2218 	}
2219 	/* else, add a new source to the filter */
2220 
2221 	if (psl && psl->sl_count >= sysctl_igmp_max_msf) {
2222 		err = -ENOBUFS;
2223 		goto done;
2224 	}
2225 	if (!psl || psl->sl_count == psl->sl_max) {
2226 		struct ip_sf_socklist *newpsl;
2227 		int count = IP_SFBLOCK;
2228 
2229 		if (psl)
2230 			count += psl->sl_max;
2231 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2232 		if (!newpsl) {
2233 			err = -ENOBUFS;
2234 			goto done;
2235 		}
2236 		newpsl->sl_max = count;
2237 		newpsl->sl_count = count - IP_SFBLOCK;
2238 		if (psl) {
2239 			for (i = 0; i < psl->sl_count; i++)
2240 				newpsl->sl_addr[i] = psl->sl_addr[i];
2241 			/* decrease mem now to avoid the memleak warning */
2242 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2243 			kfree_rcu(psl, rcu);
2244 		}
2245 		rcu_assign_pointer(pmc->sflist, newpsl);
2246 		psl = newpsl;
2247 	}
2248 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
2249 	for (i = 0; i < psl->sl_count; i++) {
2250 		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2251 			sizeof(__be32));
2252 		if (rv == 0)
2253 			break;
2254 	}
2255 	if (rv == 0)		/* address already there is an error */
2256 		goto done;
2257 	for (j = psl->sl_count-1; j >= i; j--)
2258 		psl->sl_addr[j+1] = psl->sl_addr[j];
2259 	psl->sl_addr[i] = mreqs->imr_sourceaddr;
2260 	psl->sl_count++;
2261 	err = 0;
2262 	/* update the interface list */
2263 	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2264 		&mreqs->imr_sourceaddr, 1);
2265 done:
2266 	if (leavegroup)
2267 		err = ip_mc_leave_group(sk, &imr);
2268 	return err;
2269 }
2270 
2271 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2272 {
2273 	int err = 0;
2274 	struct ip_mreqn	imr;
2275 	__be32 addr = msf->imsf_multiaddr;
2276 	struct ip_mc_socklist *pmc;
2277 	struct in_device *in_dev;
2278 	struct inet_sock *inet = inet_sk(sk);
2279 	struct ip_sf_socklist *newpsl, *psl;
2280 	struct net *net = sock_net(sk);
2281 	int leavegroup = 0;
2282 
2283 	if (!ipv4_is_multicast(addr))
2284 		return -EINVAL;
2285 	if (msf->imsf_fmode != MCAST_INCLUDE &&
2286 	    msf->imsf_fmode != MCAST_EXCLUDE)
2287 		return -EINVAL;
2288 
2289 	ASSERT_RTNL();
2290 
2291 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2292 	imr.imr_address.s_addr = msf->imsf_interface;
2293 	imr.imr_ifindex = ifindex;
2294 	in_dev = ip_mc_find_dev(net, &imr);
2295 
2296 	if (!in_dev) {
2297 		err = -ENODEV;
2298 		goto done;
2299 	}
2300 
2301 	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2302 	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2303 		leavegroup = 1;
2304 		goto done;
2305 	}
2306 
2307 	for_each_pmc_rtnl(inet, pmc) {
2308 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2309 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2310 			break;
2311 	}
2312 	if (!pmc) {		/* must have a prior join */
2313 		err = -EINVAL;
2314 		goto done;
2315 	}
2316 	if (msf->imsf_numsrc) {
2317 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2318 							   GFP_KERNEL);
2319 		if (!newpsl) {
2320 			err = -ENOBUFS;
2321 			goto done;
2322 		}
2323 		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2324 		memcpy(newpsl->sl_addr, msf->imsf_slist,
2325 			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2326 		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2327 			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2328 		if (err) {
2329 			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2330 			goto done;
2331 		}
2332 	} else {
2333 		newpsl = NULL;
2334 		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2335 				     msf->imsf_fmode, 0, NULL, 0);
2336 	}
2337 	psl = rtnl_dereference(pmc->sflist);
2338 	if (psl) {
2339 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2340 			psl->sl_count, psl->sl_addr, 0);
2341 		/* decrease mem now to avoid the memleak warning */
2342 		atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2343 		kfree_rcu(psl, rcu);
2344 	} else
2345 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2346 			0, NULL, 0);
2347 	rcu_assign_pointer(pmc->sflist, newpsl);
2348 	pmc->sfmode = msf->imsf_fmode;
2349 	err = 0;
2350 done:
2351 	if (leavegroup)
2352 		err = ip_mc_leave_group(sk, &imr);
2353 	return err;
2354 }
2355 
2356 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2357 	struct ip_msfilter __user *optval, int __user *optlen)
2358 {
2359 	int err, len, count, copycount;
2360 	struct ip_mreqn	imr;
2361 	__be32 addr = msf->imsf_multiaddr;
2362 	struct ip_mc_socklist *pmc;
2363 	struct in_device *in_dev;
2364 	struct inet_sock *inet = inet_sk(sk);
2365 	struct ip_sf_socklist *psl;
2366 	struct net *net = sock_net(sk);
2367 
2368 	if (!ipv4_is_multicast(addr))
2369 		return -EINVAL;
2370 
2371 	rtnl_lock();
2372 
2373 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2374 	imr.imr_address.s_addr = msf->imsf_interface;
2375 	imr.imr_ifindex = 0;
2376 	in_dev = ip_mc_find_dev(net, &imr);
2377 
2378 	if (!in_dev) {
2379 		err = -ENODEV;
2380 		goto done;
2381 	}
2382 	err = -EADDRNOTAVAIL;
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 		goto done;
2391 	msf->imsf_fmode = pmc->sfmode;
2392 	psl = rtnl_dereference(pmc->sflist);
2393 	rtnl_unlock();
2394 	if (!psl) {
2395 		len = 0;
2396 		count = 0;
2397 	} else {
2398 		count = psl->sl_count;
2399 	}
2400 	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2401 	len = copycount * sizeof(psl->sl_addr[0]);
2402 	msf->imsf_numsrc = count;
2403 	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2404 	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2405 		return -EFAULT;
2406 	}
2407 	if (len &&
2408 	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2409 		return -EFAULT;
2410 	return 0;
2411 done:
2412 	rtnl_unlock();
2413 	return err;
2414 }
2415 
2416 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2417 	struct group_filter __user *optval, int __user *optlen)
2418 {
2419 	int err, i, count, copycount;
2420 	struct sockaddr_in *psin;
2421 	__be32 addr;
2422 	struct ip_mc_socklist *pmc;
2423 	struct inet_sock *inet = inet_sk(sk);
2424 	struct ip_sf_socklist *psl;
2425 
2426 	psin = (struct sockaddr_in *)&gsf->gf_group;
2427 	if (psin->sin_family != AF_INET)
2428 		return -EINVAL;
2429 	addr = psin->sin_addr.s_addr;
2430 	if (!ipv4_is_multicast(addr))
2431 		return -EINVAL;
2432 
2433 	rtnl_lock();
2434 
2435 	err = -EADDRNOTAVAIL;
2436 
2437 	for_each_pmc_rtnl(inet, pmc) {
2438 		if (pmc->multi.imr_multiaddr.s_addr == addr &&
2439 		    pmc->multi.imr_ifindex == gsf->gf_interface)
2440 			break;
2441 	}
2442 	if (!pmc)		/* must have a prior join */
2443 		goto done;
2444 	gsf->gf_fmode = pmc->sfmode;
2445 	psl = rtnl_dereference(pmc->sflist);
2446 	rtnl_unlock();
2447 	count = psl ? psl->sl_count : 0;
2448 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2449 	gsf->gf_numsrc = count;
2450 	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
2451 	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
2452 		return -EFAULT;
2453 	}
2454 	for (i = 0; i < copycount; i++) {
2455 		struct sockaddr_storage ss;
2456 
2457 		psin = (struct sockaddr_in *)&ss;
2458 		memset(&ss, 0, sizeof(ss));
2459 		psin->sin_family = AF_INET;
2460 		psin->sin_addr.s_addr = psl->sl_addr[i];
2461 		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
2462 			return -EFAULT;
2463 	}
2464 	return 0;
2465 done:
2466 	rtnl_unlock();
2467 	return err;
2468 }
2469 
2470 /*
2471  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2472  */
2473 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
2474 {
2475 	struct inet_sock *inet = inet_sk(sk);
2476 	struct ip_mc_socklist *pmc;
2477 	struct ip_sf_socklist *psl;
2478 	int i;
2479 	int ret;
2480 
2481 	ret = 1;
2482 	if (!ipv4_is_multicast(loc_addr))
2483 		goto out;
2484 
2485 	rcu_read_lock();
2486 	for_each_pmc_rcu(inet, pmc) {
2487 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2488 		    pmc->multi.imr_ifindex == dif)
2489 			break;
2490 	}
2491 	ret = inet->mc_all;
2492 	if (!pmc)
2493 		goto unlock;
2494 	psl = rcu_dereference(pmc->sflist);
2495 	ret = (pmc->sfmode == MCAST_EXCLUDE);
2496 	if (!psl)
2497 		goto unlock;
2498 
2499 	for (i = 0; i < psl->sl_count; i++) {
2500 		if (psl->sl_addr[i] == rmt_addr)
2501 			break;
2502 	}
2503 	ret = 0;
2504 	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2505 		goto unlock;
2506 	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2507 		goto unlock;
2508 	ret = 1;
2509 unlock:
2510 	rcu_read_unlock();
2511 out:
2512 	return ret;
2513 }
2514 
2515 /*
2516  *	A socket is closing.
2517  */
2518 
2519 void ip_mc_drop_socket(struct sock *sk)
2520 {
2521 	struct inet_sock *inet = inet_sk(sk);
2522 	struct ip_mc_socklist *iml;
2523 	struct net *net = sock_net(sk);
2524 
2525 	if (!inet->mc_list)
2526 		return;
2527 
2528 	rtnl_lock();
2529 	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2530 		struct in_device *in_dev;
2531 
2532 		inet->mc_list = iml->next_rcu;
2533 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2534 		(void) ip_mc_leave_src(sk, iml, in_dev);
2535 		if (in_dev)
2536 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2537 		/* decrease mem now to avoid the memleak warning */
2538 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2539 		kfree_rcu(iml, rcu);
2540 	}
2541 	rtnl_unlock();
2542 }
2543 
2544 /* called with rcu_read_lock() */
2545 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)
2546 {
2547 	struct ip_mc_list *im;
2548 	struct ip_mc_list __rcu **mc_hash;
2549 	struct ip_sf_list *psf;
2550 	int rv = 0;
2551 
2552 	mc_hash = rcu_dereference(in_dev->mc_hash);
2553 	if (mc_hash) {
2554 		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2555 
2556 		for (im = rcu_dereference(mc_hash[hash]);
2557 		     im != NULL;
2558 		     im = rcu_dereference(im->next_hash)) {
2559 			if (im->multiaddr == mc_addr)
2560 				break;
2561 		}
2562 	} else {
2563 		for_each_pmc_rcu(in_dev, im) {
2564 			if (im->multiaddr == mc_addr)
2565 				break;
2566 		}
2567 	}
2568 	if (im && proto == IPPROTO_IGMP) {
2569 		rv = 1;
2570 	} else if (im) {
2571 		if (src_addr) {
2572 			for (psf = im->sources; psf; psf = psf->sf_next) {
2573 				if (psf->sf_inaddr == src_addr)
2574 					break;
2575 			}
2576 			if (psf)
2577 				rv = psf->sf_count[MCAST_INCLUDE] ||
2578 					psf->sf_count[MCAST_EXCLUDE] !=
2579 					im->sfcount[MCAST_EXCLUDE];
2580 			else
2581 				rv = im->sfcount[MCAST_EXCLUDE] != 0;
2582 		} else
2583 			rv = 1; /* unspecified source; tentatively allow */
2584 	}
2585 	return rv;
2586 }
2587 
2588 #if defined(CONFIG_PROC_FS)
2589 struct igmp_mc_iter_state {
2590 	struct seq_net_private p;
2591 	struct net_device *dev;
2592 	struct in_device *in_dev;
2593 };
2594 
2595 #define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
2596 
2597 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2598 {
2599 	struct net *net = seq_file_net(seq);
2600 	struct ip_mc_list *im = NULL;
2601 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2602 
2603 	state->in_dev = NULL;
2604 	for_each_netdev_rcu(net, state->dev) {
2605 		struct in_device *in_dev;
2606 
2607 		in_dev = __in_dev_get_rcu(state->dev);
2608 		if (!in_dev)
2609 			continue;
2610 		im = rcu_dereference(in_dev->mc_list);
2611 		if (im) {
2612 			state->in_dev = in_dev;
2613 			break;
2614 		}
2615 	}
2616 	return im;
2617 }
2618 
2619 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2620 {
2621 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2622 
2623 	im = rcu_dereference(im->next_rcu);
2624 	while (!im) {
2625 		state->dev = next_net_device_rcu(state->dev);
2626 		if (!state->dev) {
2627 			state->in_dev = NULL;
2628 			break;
2629 		}
2630 		state->in_dev = __in_dev_get_rcu(state->dev);
2631 		if (!state->in_dev)
2632 			continue;
2633 		im = rcu_dereference(state->in_dev->mc_list);
2634 	}
2635 	return im;
2636 }
2637 
2638 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2639 {
2640 	struct ip_mc_list *im = igmp_mc_get_first(seq);
2641 	if (im)
2642 		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2643 			--pos;
2644 	return pos ? NULL : im;
2645 }
2646 
2647 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2648 	__acquires(rcu)
2649 {
2650 	rcu_read_lock();
2651 	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2652 }
2653 
2654 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2655 {
2656 	struct ip_mc_list *im;
2657 	if (v == SEQ_START_TOKEN)
2658 		im = igmp_mc_get_first(seq);
2659 	else
2660 		im = igmp_mc_get_next(seq, v);
2661 	++*pos;
2662 	return im;
2663 }
2664 
2665 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2666 	__releases(rcu)
2667 {
2668 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2669 
2670 	state->in_dev = NULL;
2671 	state->dev = NULL;
2672 	rcu_read_unlock();
2673 }
2674 
2675 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2676 {
2677 	if (v == SEQ_START_TOKEN)
2678 		seq_puts(seq,
2679 			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2680 	else {
2681 		struct ip_mc_list *im = (struct ip_mc_list *)v;
2682 		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2683 		char   *querier;
2684 		long delta;
2685 
2686 #ifdef CONFIG_IP_MULTICAST
2687 		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2688 			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
2689 			  "V3";
2690 #else
2691 		querier = "NONE";
2692 #endif
2693 
2694 		if (rcu_access_pointer(state->in_dev->mc_list) == im) {
2695 			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2696 				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2697 		}
2698 
2699 		delta = im->timer.expires - jiffies;
2700 		seq_printf(seq,
2701 			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2702 			   im->multiaddr, im->users,
2703 			   im->tm_running,
2704 			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2705 			   im->reporter);
2706 	}
2707 	return 0;
2708 }
2709 
2710 static const struct seq_operations igmp_mc_seq_ops = {
2711 	.start	=	igmp_mc_seq_start,
2712 	.next	=	igmp_mc_seq_next,
2713 	.stop	=	igmp_mc_seq_stop,
2714 	.show	=	igmp_mc_seq_show,
2715 };
2716 
2717 static int igmp_mc_seq_open(struct inode *inode, struct file *file)
2718 {
2719 	return seq_open_net(inode, file, &igmp_mc_seq_ops,
2720 			sizeof(struct igmp_mc_iter_state));
2721 }
2722 
2723 static const struct file_operations igmp_mc_seq_fops = {
2724 	.owner		=	THIS_MODULE,
2725 	.open		=	igmp_mc_seq_open,
2726 	.read		=	seq_read,
2727 	.llseek		=	seq_lseek,
2728 	.release	=	seq_release_net,
2729 };
2730 
2731 struct igmp_mcf_iter_state {
2732 	struct seq_net_private p;
2733 	struct net_device *dev;
2734 	struct in_device *idev;
2735 	struct ip_mc_list *im;
2736 };
2737 
2738 #define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
2739 
2740 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2741 {
2742 	struct net *net = seq_file_net(seq);
2743 	struct ip_sf_list *psf = NULL;
2744 	struct ip_mc_list *im = NULL;
2745 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2746 
2747 	state->idev = NULL;
2748 	state->im = NULL;
2749 	for_each_netdev_rcu(net, state->dev) {
2750 		struct in_device *idev;
2751 		idev = __in_dev_get_rcu(state->dev);
2752 		if (unlikely(!idev))
2753 			continue;
2754 		im = rcu_dereference(idev->mc_list);
2755 		if (likely(im)) {
2756 			spin_lock_bh(&im->lock);
2757 			psf = im->sources;
2758 			if (likely(psf)) {
2759 				state->im = im;
2760 				state->idev = idev;
2761 				break;
2762 			}
2763 			spin_unlock_bh(&im->lock);
2764 		}
2765 	}
2766 	return psf;
2767 }
2768 
2769 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2770 {
2771 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2772 
2773 	psf = psf->sf_next;
2774 	while (!psf) {
2775 		spin_unlock_bh(&state->im->lock);
2776 		state->im = state->im->next;
2777 		while (!state->im) {
2778 			state->dev = next_net_device_rcu(state->dev);
2779 			if (!state->dev) {
2780 				state->idev = NULL;
2781 				goto out;
2782 			}
2783 			state->idev = __in_dev_get_rcu(state->dev);
2784 			if (!state->idev)
2785 				continue;
2786 			state->im = rcu_dereference(state->idev->mc_list);
2787 		}
2788 		if (!state->im)
2789 			break;
2790 		spin_lock_bh(&state->im->lock);
2791 		psf = state->im->sources;
2792 	}
2793 out:
2794 	return psf;
2795 }
2796 
2797 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2798 {
2799 	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2800 	if (psf)
2801 		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2802 			--pos;
2803 	return pos ? NULL : psf;
2804 }
2805 
2806 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2807 	__acquires(rcu)
2808 {
2809 	rcu_read_lock();
2810 	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2811 }
2812 
2813 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2814 {
2815 	struct ip_sf_list *psf;
2816 	if (v == SEQ_START_TOKEN)
2817 		psf = igmp_mcf_get_first(seq);
2818 	else
2819 		psf = igmp_mcf_get_next(seq, v);
2820 	++*pos;
2821 	return psf;
2822 }
2823 
2824 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2825 	__releases(rcu)
2826 {
2827 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2828 	if (likely(state->im)) {
2829 		spin_unlock_bh(&state->im->lock);
2830 		state->im = NULL;
2831 	}
2832 	state->idev = NULL;
2833 	state->dev = NULL;
2834 	rcu_read_unlock();
2835 }
2836 
2837 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2838 {
2839 	struct ip_sf_list *psf = (struct ip_sf_list *)v;
2840 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2841 
2842 	if (v == SEQ_START_TOKEN) {
2843 		seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
2844 	} else {
2845 		seq_printf(seq,
2846 			   "%3d %6.6s 0x%08x "
2847 			   "0x%08x %6lu %6lu\n",
2848 			   state->dev->ifindex, state->dev->name,
2849 			   ntohl(state->im->multiaddr),
2850 			   ntohl(psf->sf_inaddr),
2851 			   psf->sf_count[MCAST_INCLUDE],
2852 			   psf->sf_count[MCAST_EXCLUDE]);
2853 	}
2854 	return 0;
2855 }
2856 
2857 static const struct seq_operations igmp_mcf_seq_ops = {
2858 	.start	=	igmp_mcf_seq_start,
2859 	.next	=	igmp_mcf_seq_next,
2860 	.stop	=	igmp_mcf_seq_stop,
2861 	.show	=	igmp_mcf_seq_show,
2862 };
2863 
2864 static int igmp_mcf_seq_open(struct inode *inode, struct file *file)
2865 {
2866 	return seq_open_net(inode, file, &igmp_mcf_seq_ops,
2867 			sizeof(struct igmp_mcf_iter_state));
2868 }
2869 
2870 static const struct file_operations igmp_mcf_seq_fops = {
2871 	.owner		=	THIS_MODULE,
2872 	.open		=	igmp_mcf_seq_open,
2873 	.read		=	seq_read,
2874 	.llseek		=	seq_lseek,
2875 	.release	=	seq_release_net,
2876 };
2877 
2878 static int __net_init igmp_net_init(struct net *net)
2879 {
2880 	struct proc_dir_entry *pde;
2881 	int err;
2882 
2883 	pde = proc_create("igmp", S_IRUGO, net->proc_net, &igmp_mc_seq_fops);
2884 	if (!pde)
2885 		goto out_igmp;
2886 	pde = proc_create("mcfilter", S_IRUGO, net->proc_net,
2887 			  &igmp_mcf_seq_fops);
2888 	if (!pde)
2889 		goto out_mcfilter;
2890 	err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
2891 				   SOCK_DGRAM, 0, net);
2892 	if (err < 0) {
2893 		pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
2894 		       err);
2895 		goto out_sock;
2896 	}
2897 
2898 	return 0;
2899 
2900 out_sock:
2901 	remove_proc_entry("mcfilter", net->proc_net);
2902 out_mcfilter:
2903 	remove_proc_entry("igmp", net->proc_net);
2904 out_igmp:
2905 	return -ENOMEM;
2906 }
2907 
2908 static void __net_exit igmp_net_exit(struct net *net)
2909 {
2910 	remove_proc_entry("mcfilter", net->proc_net);
2911 	remove_proc_entry("igmp", net->proc_net);
2912 	inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
2913 }
2914 
2915 static struct pernet_operations igmp_net_ops = {
2916 	.init = igmp_net_init,
2917 	.exit = igmp_net_exit,
2918 };
2919 #endif
2920 
2921 static int igmp_netdev_event(struct notifier_block *this,
2922 			     unsigned long event, void *ptr)
2923 {
2924 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2925 	struct in_device *in_dev;
2926 
2927 	switch (event) {
2928 	case NETDEV_RESEND_IGMP:
2929 		in_dev = __in_dev_get_rtnl(dev);
2930 		if (in_dev)
2931 			ip_mc_rejoin_groups(in_dev);
2932 		break;
2933 	default:
2934 		break;
2935 	}
2936 	return NOTIFY_DONE;
2937 }
2938 
2939 static struct notifier_block igmp_notifier = {
2940 	.notifier_call = igmp_netdev_event,
2941 };
2942 
2943 int __init igmp_mc_init(void)
2944 {
2945 #if defined(CONFIG_PROC_FS)
2946 	int err;
2947 
2948 	err = register_pernet_subsys(&igmp_net_ops);
2949 	if (err)
2950 		return err;
2951 	err = register_netdevice_notifier(&igmp_notifier);
2952 	if (err)
2953 		goto reg_notif_fail;
2954 	return 0;
2955 
2956 reg_notif_fail:
2957 	unregister_pernet_subsys(&igmp_net_ops);
2958 	return err;
2959 #else
2960 	return register_netdevice_notifier(&igmp_notifier);
2961 #endif
2962 }
2963