xref: /openbmc/linux/net/ipv4/igmp.c (revision c1d45424)
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 
92 #include <net/net_namespace.h>
93 #include <net/arp.h>
94 #include <net/ip.h>
95 #include <net/protocol.h>
96 #include <net/route.h>
97 #include <net/sock.h>
98 #include <net/checksum.h>
99 #include <linux/netfilter_ipv4.h>
100 #ifdef CONFIG_IP_MROUTE
101 #include <linux/mroute.h>
102 #endif
103 #ifdef CONFIG_PROC_FS
104 #include <linux/proc_fs.h>
105 #include <linux/seq_file.h>
106 #endif
107 
108 #define IP_MAX_MEMBERSHIPS	20
109 #define IP_MAX_MSF		10
110 
111 #ifdef CONFIG_IP_MULTICAST
112 /* Parameter names and values are taken from igmp-v2-06 draft */
113 
114 #define IGMP_V1_Router_Present_Timeout		(400*HZ)
115 #define IGMP_V2_Router_Present_Timeout		(400*HZ)
116 #define IGMP_Unsolicited_Report_Interval	(10*HZ)
117 #define IGMP_Query_Response_Interval		(10*HZ)
118 #define IGMP_Unsolicited_Report_Count		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 void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
142 static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr);
143 static void igmpv3_clear_delrec(struct in_device *in_dev);
144 static int sf_setstate(struct ip_mc_list *pmc);
145 static void sf_markstate(struct ip_mc_list *pmc);
146 #endif
147 static void ip_mc_clear_src(struct ip_mc_list *pmc);
148 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
149 			 int sfcount, __be32 *psfsrc, int delta);
150 
151 static void ip_ma_put(struct ip_mc_list *im)
152 {
153 	if (atomic_dec_and_test(&im->refcnt)) {
154 		in_dev_put(im->interface);
155 		kfree_rcu(im, rcu);
156 	}
157 }
158 
159 #define for_each_pmc_rcu(in_dev, pmc)				\
160 	for (pmc = rcu_dereference(in_dev->mc_list);		\
161 	     pmc != NULL;					\
162 	     pmc = rcu_dereference(pmc->next_rcu))
163 
164 #define for_each_pmc_rtnl(in_dev, pmc)				\
165 	for (pmc = rtnl_dereference(in_dev->mc_list);		\
166 	     pmc != NULL;					\
167 	     pmc = rtnl_dereference(pmc->next_rcu))
168 
169 #ifdef CONFIG_IP_MULTICAST
170 
171 /*
172  *	Timer management
173  */
174 
175 static void igmp_stop_timer(struct ip_mc_list *im)
176 {
177 	spin_lock_bh(&im->lock);
178 	if (del_timer(&im->timer))
179 		atomic_dec(&im->refcnt);
180 	im->tm_running = 0;
181 	im->reporter = 0;
182 	im->unsolicit_count = 0;
183 	spin_unlock_bh(&im->lock);
184 }
185 
186 /* It must be called with locked im->lock */
187 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
188 {
189 	int tv = net_random() % max_delay;
190 
191 	im->tm_running = 1;
192 	if (!mod_timer(&im->timer, jiffies+tv+2))
193 		atomic_inc(&im->refcnt);
194 }
195 
196 static void igmp_gq_start_timer(struct in_device *in_dev)
197 {
198 	int tv = net_random() % in_dev->mr_maxdelay;
199 
200 	in_dev->mr_gq_running = 1;
201 	if (!mod_timer(&in_dev->mr_gq_timer, jiffies+tv+2))
202 		in_dev_hold(in_dev);
203 }
204 
205 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
206 {
207 	int tv = net_random() % delay;
208 
209 	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
210 		in_dev_hold(in_dev);
211 }
212 
213 static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
214 {
215 	spin_lock_bh(&im->lock);
216 	im->unsolicit_count = 0;
217 	if (del_timer(&im->timer)) {
218 		if ((long)(im->timer.expires-jiffies) < max_delay) {
219 			add_timer(&im->timer);
220 			im->tm_running = 1;
221 			spin_unlock_bh(&im->lock);
222 			return;
223 		}
224 		atomic_dec(&im->refcnt);
225 	}
226 	igmp_start_timer(im, max_delay);
227 	spin_unlock_bh(&im->lock);
228 }
229 
230 
231 /*
232  *	Send an IGMP report.
233  */
234 
235 #define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
236 
237 
238 static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
239 	int gdeleted, int sdeleted)
240 {
241 	switch (type) {
242 	case IGMPV3_MODE_IS_INCLUDE:
243 	case IGMPV3_MODE_IS_EXCLUDE:
244 		if (gdeleted || sdeleted)
245 			return 0;
246 		if (!(pmc->gsquery && !psf->sf_gsresp)) {
247 			if (pmc->sfmode == MCAST_INCLUDE)
248 				return 1;
249 			/* don't include if this source is excluded
250 			 * in all filters
251 			 */
252 			if (psf->sf_count[MCAST_INCLUDE])
253 				return type == IGMPV3_MODE_IS_INCLUDE;
254 			return pmc->sfcount[MCAST_EXCLUDE] ==
255 				psf->sf_count[MCAST_EXCLUDE];
256 		}
257 		return 0;
258 	case IGMPV3_CHANGE_TO_INCLUDE:
259 		if (gdeleted || sdeleted)
260 			return 0;
261 		return psf->sf_count[MCAST_INCLUDE] != 0;
262 	case IGMPV3_CHANGE_TO_EXCLUDE:
263 		if (gdeleted || sdeleted)
264 			return 0;
265 		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
266 		    psf->sf_count[MCAST_INCLUDE])
267 			return 0;
268 		return pmc->sfcount[MCAST_EXCLUDE] ==
269 			psf->sf_count[MCAST_EXCLUDE];
270 	case IGMPV3_ALLOW_NEW_SOURCES:
271 		if (gdeleted || !psf->sf_crcount)
272 			return 0;
273 		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
274 	case IGMPV3_BLOCK_OLD_SOURCES:
275 		if (pmc->sfmode == MCAST_INCLUDE)
276 			return gdeleted || (psf->sf_crcount && sdeleted);
277 		return psf->sf_crcount && !gdeleted && !sdeleted;
278 	}
279 	return 0;
280 }
281 
282 static int
283 igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
284 {
285 	struct ip_sf_list *psf;
286 	int scount = 0;
287 
288 	for (psf=pmc->sources; psf; psf=psf->sf_next) {
289 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
290 			continue;
291 		scount++;
292 	}
293 	return scount;
294 }
295 
296 #define igmp_skb_size(skb) (*(unsigned int *)((skb)->cb))
297 
298 static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
299 {
300 	struct sk_buff *skb;
301 	struct rtable *rt;
302 	struct iphdr *pip;
303 	struct igmpv3_report *pig;
304 	struct net *net = dev_net(dev);
305 	struct flowi4 fl4;
306 	int hlen = LL_RESERVED_SPACE(dev);
307 	int tlen = dev->needed_tailroom;
308 
309 	while (1) {
310 		skb = alloc_skb(size + hlen + tlen,
311 				GFP_ATOMIC | __GFP_NOWARN);
312 		if (skb)
313 			break;
314 		size >>= 1;
315 		if (size < 256)
316 			return NULL;
317 	}
318 	igmp_skb_size(skb) = size;
319 
320 	rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
321 				   0, 0,
322 				   IPPROTO_IGMP, 0, dev->ifindex);
323 	if (IS_ERR(rt)) {
324 		kfree_skb(skb);
325 		return NULL;
326 	}
327 
328 	skb_dst_set(skb, &rt->dst);
329 	skb->dev = dev;
330 
331 	skb_reserve(skb, hlen);
332 
333 	skb_reset_network_header(skb);
334 	pip = ip_hdr(skb);
335 	skb_put(skb, sizeof(struct iphdr) + 4);
336 
337 	pip->version  = 4;
338 	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
339 	pip->tos      = 0xc0;
340 	pip->frag_off = htons(IP_DF);
341 	pip->ttl      = 1;
342 	pip->daddr    = fl4.daddr;
343 	pip->saddr    = fl4.saddr;
344 	pip->protocol = IPPROTO_IGMP;
345 	pip->tot_len  = 0;	/* filled in later */
346 	ip_select_ident(pip, &rt->dst, NULL);
347 	((u8 *)&pip[1])[0] = IPOPT_RA;
348 	((u8 *)&pip[1])[1] = 4;
349 	((u8 *)&pip[1])[2] = 0;
350 	((u8 *)&pip[1])[3] = 0;
351 
352 	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
353 	skb_put(skb, sizeof(*pig));
354 	pig = igmpv3_report_hdr(skb);
355 	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
356 	pig->resv1 = 0;
357 	pig->csum = 0;
358 	pig->resv2 = 0;
359 	pig->ngrec = 0;
360 	return skb;
361 }
362 
363 static int igmpv3_sendpack(struct sk_buff *skb)
364 {
365 	struct igmphdr *pig = igmp_hdr(skb);
366 	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
367 
368 	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
369 
370 	return ip_local_out(skb);
371 }
372 
373 static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
374 {
375 	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
376 }
377 
378 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
379 	int type, struct igmpv3_grec **ppgr)
380 {
381 	struct net_device *dev = pmc->interface->dev;
382 	struct igmpv3_report *pih;
383 	struct igmpv3_grec *pgr;
384 
385 	if (!skb)
386 		skb = igmpv3_newpack(dev, dev->mtu);
387 	if (!skb)
388 		return NULL;
389 	pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
390 	pgr->grec_type = type;
391 	pgr->grec_auxwords = 0;
392 	pgr->grec_nsrcs = 0;
393 	pgr->grec_mca = pmc->multiaddr;
394 	pih = igmpv3_report_hdr(skb);
395 	pih->ngrec = htons(ntohs(pih->ngrec)+1);
396 	*ppgr = pgr;
397 	return skb;
398 }
399 
400 #define AVAILABLE(skb) ((skb) ? ((skb)->dev ? igmp_skb_size(skb) - (skb)->len : \
401 	skb_tailroom(skb)) : 0)
402 
403 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
404 	int type, int gdeleted, int sdeleted)
405 {
406 	struct net_device *dev = pmc->interface->dev;
407 	struct igmpv3_report *pih;
408 	struct igmpv3_grec *pgr = NULL;
409 	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
410 	int scount, stotal, first, isquery, truncate;
411 
412 	if (pmc->multiaddr == IGMP_ALL_HOSTS)
413 		return skb;
414 
415 	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
416 		  type == IGMPV3_MODE_IS_EXCLUDE;
417 	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
418 		    type == IGMPV3_CHANGE_TO_EXCLUDE;
419 
420 	stotal = scount = 0;
421 
422 	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
423 
424 	if (!*psf_list)
425 		goto empty_source;
426 
427 	pih = skb ? igmpv3_report_hdr(skb) : NULL;
428 
429 	/* EX and TO_EX get a fresh packet, if needed */
430 	if (truncate) {
431 		if (pih && pih->ngrec &&
432 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
433 			if (skb)
434 				igmpv3_sendpack(skb);
435 			skb = igmpv3_newpack(dev, dev->mtu);
436 		}
437 	}
438 	first = 1;
439 	psf_prev = NULL;
440 	for (psf=*psf_list; psf; psf=psf_next) {
441 		__be32 *psrc;
442 
443 		psf_next = psf->sf_next;
444 
445 		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
446 			psf_prev = psf;
447 			continue;
448 		}
449 
450 		/* clear marks on query responses */
451 		if (isquery)
452 			psf->sf_gsresp = 0;
453 
454 		if (AVAILABLE(skb) < sizeof(__be32) +
455 		    first*sizeof(struct igmpv3_grec)) {
456 			if (truncate && !first)
457 				break;	 /* truncate these */
458 			if (pgr)
459 				pgr->grec_nsrcs = htons(scount);
460 			if (skb)
461 				igmpv3_sendpack(skb);
462 			skb = igmpv3_newpack(dev, dev->mtu);
463 			first = 1;
464 			scount = 0;
465 		}
466 		if (first) {
467 			skb = add_grhead(skb, pmc, type, &pgr);
468 			first = 0;
469 		}
470 		if (!skb)
471 			return NULL;
472 		psrc = (__be32 *)skb_put(skb, sizeof(__be32));
473 		*psrc = psf->sf_inaddr;
474 		scount++; stotal++;
475 		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
476 		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
477 			psf->sf_crcount--;
478 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
479 				if (psf_prev)
480 					psf_prev->sf_next = psf->sf_next;
481 				else
482 					*psf_list = psf->sf_next;
483 				kfree(psf);
484 				continue;
485 			}
486 		}
487 		psf_prev = psf;
488 	}
489 
490 empty_source:
491 	if (!stotal) {
492 		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
493 		    type == IGMPV3_BLOCK_OLD_SOURCES)
494 			return skb;
495 		if (pmc->crcount || isquery) {
496 			/* make sure we have room for group header */
497 			if (skb && AVAILABLE(skb)<sizeof(struct igmpv3_grec)) {
498 				igmpv3_sendpack(skb);
499 				skb = NULL; /* add_grhead will get a new one */
500 			}
501 			skb = add_grhead(skb, pmc, type, &pgr);
502 		}
503 	}
504 	if (pgr)
505 		pgr->grec_nsrcs = htons(scount);
506 
507 	if (isquery)
508 		pmc->gsquery = 0;	/* clear query state on report */
509 	return skb;
510 }
511 
512 static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
513 {
514 	struct sk_buff *skb = NULL;
515 	int type;
516 
517 	if (!pmc) {
518 		rcu_read_lock();
519 		for_each_pmc_rcu(in_dev, pmc) {
520 			if (pmc->multiaddr == IGMP_ALL_HOSTS)
521 				continue;
522 			spin_lock_bh(&pmc->lock);
523 			if (pmc->sfcount[MCAST_EXCLUDE])
524 				type = IGMPV3_MODE_IS_EXCLUDE;
525 			else
526 				type = IGMPV3_MODE_IS_INCLUDE;
527 			skb = add_grec(skb, pmc, type, 0, 0);
528 			spin_unlock_bh(&pmc->lock);
529 		}
530 		rcu_read_unlock();
531 	} else {
532 		spin_lock_bh(&pmc->lock);
533 		if (pmc->sfcount[MCAST_EXCLUDE])
534 			type = IGMPV3_MODE_IS_EXCLUDE;
535 		else
536 			type = IGMPV3_MODE_IS_INCLUDE;
537 		skb = add_grec(skb, pmc, type, 0, 0);
538 		spin_unlock_bh(&pmc->lock);
539 	}
540 	if (!skb)
541 		return 0;
542 	return igmpv3_sendpack(skb);
543 }
544 
545 /*
546  * remove zero-count source records from a source filter list
547  */
548 static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
549 {
550 	struct ip_sf_list *psf_prev, *psf_next, *psf;
551 
552 	psf_prev = NULL;
553 	for (psf=*ppsf; psf; psf = psf_next) {
554 		psf_next = psf->sf_next;
555 		if (psf->sf_crcount == 0) {
556 			if (psf_prev)
557 				psf_prev->sf_next = psf->sf_next;
558 			else
559 				*ppsf = psf->sf_next;
560 			kfree(psf);
561 		} else
562 			psf_prev = psf;
563 	}
564 }
565 
566 static void igmpv3_send_cr(struct in_device *in_dev)
567 {
568 	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
569 	struct sk_buff *skb = NULL;
570 	int type, dtype;
571 
572 	rcu_read_lock();
573 	spin_lock_bh(&in_dev->mc_tomb_lock);
574 
575 	/* deleted MCA's */
576 	pmc_prev = NULL;
577 	for (pmc=in_dev->mc_tomb; pmc; pmc=pmc_next) {
578 		pmc_next = pmc->next;
579 		if (pmc->sfmode == MCAST_INCLUDE) {
580 			type = IGMPV3_BLOCK_OLD_SOURCES;
581 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
582 			skb = add_grec(skb, pmc, type, 1, 0);
583 			skb = add_grec(skb, pmc, dtype, 1, 1);
584 		}
585 		if (pmc->crcount) {
586 			if (pmc->sfmode == MCAST_EXCLUDE) {
587 				type = IGMPV3_CHANGE_TO_INCLUDE;
588 				skb = add_grec(skb, pmc, type, 1, 0);
589 			}
590 			pmc->crcount--;
591 			if (pmc->crcount == 0) {
592 				igmpv3_clear_zeros(&pmc->tomb);
593 				igmpv3_clear_zeros(&pmc->sources);
594 			}
595 		}
596 		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
597 			if (pmc_prev)
598 				pmc_prev->next = pmc_next;
599 			else
600 				in_dev->mc_tomb = pmc_next;
601 			in_dev_put(pmc->interface);
602 			kfree(pmc);
603 		} else
604 			pmc_prev = pmc;
605 	}
606 	spin_unlock_bh(&in_dev->mc_tomb_lock);
607 
608 	/* change recs */
609 	for_each_pmc_rcu(in_dev, pmc) {
610 		spin_lock_bh(&pmc->lock);
611 		if (pmc->sfcount[MCAST_EXCLUDE]) {
612 			type = IGMPV3_BLOCK_OLD_SOURCES;
613 			dtype = IGMPV3_ALLOW_NEW_SOURCES;
614 		} else {
615 			type = IGMPV3_ALLOW_NEW_SOURCES;
616 			dtype = IGMPV3_BLOCK_OLD_SOURCES;
617 		}
618 		skb = add_grec(skb, pmc, type, 0, 0);
619 		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
620 
621 		/* filter mode changes */
622 		if (pmc->crcount) {
623 			if (pmc->sfmode == MCAST_EXCLUDE)
624 				type = IGMPV3_CHANGE_TO_EXCLUDE;
625 			else
626 				type = IGMPV3_CHANGE_TO_INCLUDE;
627 			skb = add_grec(skb, pmc, type, 0, 0);
628 			pmc->crcount--;
629 		}
630 		spin_unlock_bh(&pmc->lock);
631 	}
632 	rcu_read_unlock();
633 
634 	if (!skb)
635 		return;
636 	(void) igmpv3_sendpack(skb);
637 }
638 
639 static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
640 	int type)
641 {
642 	struct sk_buff *skb;
643 	struct iphdr *iph;
644 	struct igmphdr *ih;
645 	struct rtable *rt;
646 	struct net_device *dev = in_dev->dev;
647 	struct net *net = dev_net(dev);
648 	__be32	group = pmc ? pmc->multiaddr : 0;
649 	struct flowi4 fl4;
650 	__be32	dst;
651 	int hlen, tlen;
652 
653 	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
654 		return igmpv3_send_report(in_dev, pmc);
655 	else if (type == IGMP_HOST_LEAVE_MESSAGE)
656 		dst = IGMP_ALL_ROUTER;
657 	else
658 		dst = group;
659 
660 	rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
661 				   0, 0,
662 				   IPPROTO_IGMP, 0, dev->ifindex);
663 	if (IS_ERR(rt))
664 		return -1;
665 
666 	hlen = LL_RESERVED_SPACE(dev);
667 	tlen = dev->needed_tailroom;
668 	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
669 	if (skb == NULL) {
670 		ip_rt_put(rt);
671 		return -1;
672 	}
673 
674 	skb_dst_set(skb, &rt->dst);
675 
676 	skb_reserve(skb, hlen);
677 
678 	skb_reset_network_header(skb);
679 	iph = ip_hdr(skb);
680 	skb_put(skb, sizeof(struct iphdr) + 4);
681 
682 	iph->version  = 4;
683 	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
684 	iph->tos      = 0xc0;
685 	iph->frag_off = htons(IP_DF);
686 	iph->ttl      = 1;
687 	iph->daddr    = dst;
688 	iph->saddr    = fl4.saddr;
689 	iph->protocol = IPPROTO_IGMP;
690 	ip_select_ident(iph, &rt->dst, NULL);
691 	((u8 *)&iph[1])[0] = IPOPT_RA;
692 	((u8 *)&iph[1])[1] = 4;
693 	((u8 *)&iph[1])[2] = 0;
694 	((u8 *)&iph[1])[3] = 0;
695 
696 	ih = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
697 	ih->type = type;
698 	ih->code = 0;
699 	ih->csum = 0;
700 	ih->group = group;
701 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
702 
703 	return ip_local_out(skb);
704 }
705 
706 static void igmp_gq_timer_expire(unsigned long data)
707 {
708 	struct in_device *in_dev = (struct in_device *)data;
709 
710 	in_dev->mr_gq_running = 0;
711 	igmpv3_send_report(in_dev, NULL);
712 	__in_dev_put(in_dev);
713 }
714 
715 static void igmp_ifc_timer_expire(unsigned long data)
716 {
717 	struct in_device *in_dev = (struct in_device *)data;
718 
719 	igmpv3_send_cr(in_dev);
720 	if (in_dev->mr_ifc_count) {
721 		in_dev->mr_ifc_count--;
722 		igmp_ifc_start_timer(in_dev, IGMP_Unsolicited_Report_Interval);
723 	}
724 	__in_dev_put(in_dev);
725 }
726 
727 static void igmp_ifc_event(struct in_device *in_dev)
728 {
729 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
730 		return;
731 	in_dev->mr_ifc_count = in_dev->mr_qrv ? in_dev->mr_qrv :
732 		IGMP_Unsolicited_Report_Count;
733 	igmp_ifc_start_timer(in_dev, 1);
734 }
735 
736 
737 static void igmp_timer_expire(unsigned long data)
738 {
739 	struct ip_mc_list *im=(struct ip_mc_list *)data;
740 	struct in_device *in_dev = im->interface;
741 
742 	spin_lock(&im->lock);
743 	im->tm_running = 0;
744 
745 	if (im->unsolicit_count) {
746 		im->unsolicit_count--;
747 		igmp_start_timer(im, IGMP_Unsolicited_Report_Interval);
748 	}
749 	im->reporter = 1;
750 	spin_unlock(&im->lock);
751 
752 	if (IGMP_V1_SEEN(in_dev))
753 		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
754 	else if (IGMP_V2_SEEN(in_dev))
755 		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
756 	else
757 		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
758 
759 	ip_ma_put(im);
760 }
761 
762 /* mark EXCLUDE-mode sources */
763 static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
764 {
765 	struct ip_sf_list *psf;
766 	int i, scount;
767 
768 	scount = 0;
769 	for (psf=pmc->sources; psf; psf=psf->sf_next) {
770 		if (scount == nsrcs)
771 			break;
772 		for (i=0; i<nsrcs; i++) {
773 			/* skip inactive filters */
774 			if (psf->sf_count[MCAST_INCLUDE] ||
775 			    pmc->sfcount[MCAST_EXCLUDE] !=
776 			    psf->sf_count[MCAST_EXCLUDE])
777 				break;
778 			if (srcs[i] == psf->sf_inaddr) {
779 				scount++;
780 				break;
781 			}
782 		}
783 	}
784 	pmc->gsquery = 0;
785 	if (scount == nsrcs)	/* all sources excluded */
786 		return 0;
787 	return 1;
788 }
789 
790 static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
791 {
792 	struct ip_sf_list *psf;
793 	int i, scount;
794 
795 	if (pmc->sfmode == MCAST_EXCLUDE)
796 		return igmp_xmarksources(pmc, nsrcs, srcs);
797 
798 	/* mark INCLUDE-mode sources */
799 	scount = 0;
800 	for (psf=pmc->sources; psf; psf=psf->sf_next) {
801 		if (scount == nsrcs)
802 			break;
803 		for (i=0; i<nsrcs; i++)
804 			if (srcs[i] == psf->sf_inaddr) {
805 				psf->sf_gsresp = 1;
806 				scount++;
807 				break;
808 			}
809 	}
810 	if (!scount) {
811 		pmc->gsquery = 0;
812 		return 0;
813 	}
814 	pmc->gsquery = 1;
815 	return 1;
816 }
817 
818 /* return true if packet was dropped */
819 static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
820 {
821 	struct ip_mc_list *im;
822 
823 	/* Timers are only set for non-local groups */
824 
825 	if (group == IGMP_ALL_HOSTS)
826 		return false;
827 
828 	rcu_read_lock();
829 	for_each_pmc_rcu(in_dev, im) {
830 		if (im->multiaddr == group) {
831 			igmp_stop_timer(im);
832 			break;
833 		}
834 	}
835 	rcu_read_unlock();
836 	return false;
837 }
838 
839 /* return true if packet was dropped */
840 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
841 	int len)
842 {
843 	struct igmphdr 		*ih = igmp_hdr(skb);
844 	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
845 	struct ip_mc_list	*im;
846 	__be32			group = ih->group;
847 	int			max_delay;
848 	int			mark = 0;
849 
850 
851 	if (len == 8) {
852 		if (ih->code == 0) {
853 			/* Alas, old v1 router presents here. */
854 
855 			max_delay = IGMP_Query_Response_Interval;
856 			in_dev->mr_v1_seen = jiffies +
857 				IGMP_V1_Router_Present_Timeout;
858 			group = 0;
859 		} else {
860 			/* v2 router present */
861 			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
862 			in_dev->mr_v2_seen = jiffies +
863 				IGMP_V2_Router_Present_Timeout;
864 		}
865 		/* cancel the interface change timer */
866 		in_dev->mr_ifc_count = 0;
867 		if (del_timer(&in_dev->mr_ifc_timer))
868 			__in_dev_put(in_dev);
869 		/* clear deleted report items */
870 		igmpv3_clear_delrec(in_dev);
871 	} else if (len < 12) {
872 		return true;	/* ignore bogus packet; freed by caller */
873 	} else if (IGMP_V1_SEEN(in_dev)) {
874 		/* This is a v3 query with v1 queriers present */
875 		max_delay = IGMP_Query_Response_Interval;
876 		group = 0;
877 	} else if (IGMP_V2_SEEN(in_dev)) {
878 		/* this is a v3 query with v2 queriers present;
879 		 * Interpretation of the max_delay code is problematic here.
880 		 * A real v2 host would use ih_code directly, while v3 has a
881 		 * different encoding. We use the v3 encoding as more likely
882 		 * to be intended in a v3 query.
883 		 */
884 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
885 		if (!max_delay)
886 			max_delay = 1;	/* can't mod w/ 0 */
887 	} else { /* v3 */
888 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
889 			return true;
890 
891 		ih3 = igmpv3_query_hdr(skb);
892 		if (ih3->nsrcs) {
893 			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
894 					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
895 				return true;
896 			ih3 = igmpv3_query_hdr(skb);
897 		}
898 
899 		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
900 		if (!max_delay)
901 			max_delay = 1;	/* can't mod w/ 0 */
902 		in_dev->mr_maxdelay = max_delay;
903 		if (ih3->qrv)
904 			in_dev->mr_qrv = ih3->qrv;
905 		if (!group) { /* general query */
906 			if (ih3->nsrcs)
907 				return false;	/* no sources allowed */
908 			igmp_gq_start_timer(in_dev);
909 			return false;
910 		}
911 		/* mark sources to include, if group & source-specific */
912 		mark = ih3->nsrcs != 0;
913 	}
914 
915 	/*
916 	 * - Start the timers in all of our membership records
917 	 *   that the query applies to for the interface on
918 	 *   which the query arrived excl. those that belong
919 	 *   to a "local" group (224.0.0.X)
920 	 * - For timers already running check if they need to
921 	 *   be reset.
922 	 * - Use the igmp->igmp_code field as the maximum
923 	 *   delay possible
924 	 */
925 	rcu_read_lock();
926 	for_each_pmc_rcu(in_dev, im) {
927 		int changed;
928 
929 		if (group && group != im->multiaddr)
930 			continue;
931 		if (im->multiaddr == IGMP_ALL_HOSTS)
932 			continue;
933 		spin_lock_bh(&im->lock);
934 		if (im->tm_running)
935 			im->gsquery = im->gsquery && mark;
936 		else
937 			im->gsquery = mark;
938 		changed = !im->gsquery ||
939 			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
940 		spin_unlock_bh(&im->lock);
941 		if (changed)
942 			igmp_mod_timer(im, max_delay);
943 	}
944 	rcu_read_unlock();
945 	return false;
946 }
947 
948 /* called in rcu_read_lock() section */
949 int igmp_rcv(struct sk_buff *skb)
950 {
951 	/* This basically follows the spec line by line -- see RFC1112 */
952 	struct igmphdr *ih;
953 	struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
954 	int len = skb->len;
955 	bool dropped = true;
956 
957 	if (in_dev == NULL)
958 		goto drop;
959 
960 	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
961 		goto drop;
962 
963 	switch (skb->ip_summed) {
964 	case CHECKSUM_COMPLETE:
965 		if (!csum_fold(skb->csum))
966 			break;
967 		/* fall through */
968 	case CHECKSUM_NONE:
969 		skb->csum = 0;
970 		if (__skb_checksum_complete(skb))
971 			goto drop;
972 	}
973 
974 	ih = igmp_hdr(skb);
975 	switch (ih->type) {
976 	case IGMP_HOST_MEMBERSHIP_QUERY:
977 		dropped = igmp_heard_query(in_dev, skb, len);
978 		break;
979 	case IGMP_HOST_MEMBERSHIP_REPORT:
980 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
981 		/* Is it our report looped back? */
982 		if (rt_is_output_route(skb_rtable(skb)))
983 			break;
984 		/* don't rely on MC router hearing unicast reports */
985 		if (skb->pkt_type == PACKET_MULTICAST ||
986 		    skb->pkt_type == PACKET_BROADCAST)
987 			dropped = igmp_heard_report(in_dev, ih->group);
988 		break;
989 	case IGMP_PIM:
990 #ifdef CONFIG_IP_PIMSM_V1
991 		return pim_rcv_v1(skb);
992 #endif
993 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
994 	case IGMP_DVMRP:
995 	case IGMP_TRACE:
996 	case IGMP_HOST_LEAVE_MESSAGE:
997 	case IGMP_MTRACE:
998 	case IGMP_MTRACE_RESP:
999 		break;
1000 	default:
1001 		break;
1002 	}
1003 
1004 drop:
1005 	if (dropped)
1006 		kfree_skb(skb);
1007 	else
1008 		consume_skb(skb);
1009 	return 0;
1010 }
1011 
1012 #endif
1013 
1014 
1015 /*
1016  *	Add a filter to a device
1017  */
1018 
1019 static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
1020 {
1021 	char buf[MAX_ADDR_LEN];
1022 	struct net_device *dev = in_dev->dev;
1023 
1024 	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
1025 	   We will get multicast token leakage, when IFF_MULTICAST
1026 	   is changed. This check should be done in ndo_set_rx_mode
1027 	   routine. Something sort of:
1028 	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
1029 	   --ANK
1030 	   */
1031 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1032 		dev_mc_add(dev, buf);
1033 }
1034 
1035 /*
1036  *	Remove a filter from a device
1037  */
1038 
1039 static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
1040 {
1041 	char buf[MAX_ADDR_LEN];
1042 	struct net_device *dev = in_dev->dev;
1043 
1044 	if (arp_mc_map(addr, buf, dev, 0) == 0)
1045 		dev_mc_del(dev, buf);
1046 }
1047 
1048 #ifdef CONFIG_IP_MULTICAST
1049 /*
1050  * deleted ip_mc_list manipulation
1051  */
1052 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1053 {
1054 	struct ip_mc_list *pmc;
1055 
1056 	/* this is an "ip_mc_list" for convenience; only the fields below
1057 	 * are actually used. In particular, the refcnt and users are not
1058 	 * used for management of the delete list. Using the same structure
1059 	 * for deleted items allows change reports to use common code with
1060 	 * non-deleted or query-response MCA's.
1061 	 */
1062 	pmc = kzalloc(sizeof(*pmc), GFP_KERNEL);
1063 	if (!pmc)
1064 		return;
1065 	spin_lock_bh(&im->lock);
1066 	pmc->interface = im->interface;
1067 	in_dev_hold(in_dev);
1068 	pmc->multiaddr = im->multiaddr;
1069 	pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
1070 		IGMP_Unsolicited_Report_Count;
1071 	pmc->sfmode = im->sfmode;
1072 	if (pmc->sfmode == MCAST_INCLUDE) {
1073 		struct ip_sf_list *psf;
1074 
1075 		pmc->tomb = im->tomb;
1076 		pmc->sources = im->sources;
1077 		im->tomb = im->sources = NULL;
1078 		for (psf=pmc->sources; psf; psf=psf->sf_next)
1079 			psf->sf_crcount = pmc->crcount;
1080 	}
1081 	spin_unlock_bh(&im->lock);
1082 
1083 	spin_lock_bh(&in_dev->mc_tomb_lock);
1084 	pmc->next = in_dev->mc_tomb;
1085 	in_dev->mc_tomb = pmc;
1086 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1087 }
1088 
1089 static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr)
1090 {
1091 	struct ip_mc_list *pmc, *pmc_prev;
1092 	struct ip_sf_list *psf, *psf_next;
1093 
1094 	spin_lock_bh(&in_dev->mc_tomb_lock);
1095 	pmc_prev = NULL;
1096 	for (pmc=in_dev->mc_tomb; pmc; pmc=pmc->next) {
1097 		if (pmc->multiaddr == multiaddr)
1098 			break;
1099 		pmc_prev = pmc;
1100 	}
1101 	if (pmc) {
1102 		if (pmc_prev)
1103 			pmc_prev->next = pmc->next;
1104 		else
1105 			in_dev->mc_tomb = pmc->next;
1106 	}
1107 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1108 	if (pmc) {
1109 		for (psf=pmc->tomb; psf; psf=psf_next) {
1110 			psf_next = psf->sf_next;
1111 			kfree(psf);
1112 		}
1113 		in_dev_put(pmc->interface);
1114 		kfree(pmc);
1115 	}
1116 }
1117 
1118 static void igmpv3_clear_delrec(struct in_device *in_dev)
1119 {
1120 	struct ip_mc_list *pmc, *nextpmc;
1121 
1122 	spin_lock_bh(&in_dev->mc_tomb_lock);
1123 	pmc = in_dev->mc_tomb;
1124 	in_dev->mc_tomb = NULL;
1125 	spin_unlock_bh(&in_dev->mc_tomb_lock);
1126 
1127 	for (; pmc; pmc = nextpmc) {
1128 		nextpmc = pmc->next;
1129 		ip_mc_clear_src(pmc);
1130 		in_dev_put(pmc->interface);
1131 		kfree(pmc);
1132 	}
1133 	/* clear dead sources, too */
1134 	rcu_read_lock();
1135 	for_each_pmc_rcu(in_dev, pmc) {
1136 		struct ip_sf_list *psf, *psf_next;
1137 
1138 		spin_lock_bh(&pmc->lock);
1139 		psf = pmc->tomb;
1140 		pmc->tomb = NULL;
1141 		spin_unlock_bh(&pmc->lock);
1142 		for (; psf; psf=psf_next) {
1143 			psf_next = psf->sf_next;
1144 			kfree(psf);
1145 		}
1146 	}
1147 	rcu_read_unlock();
1148 }
1149 #endif
1150 
1151 static void igmp_group_dropped(struct ip_mc_list *im)
1152 {
1153 	struct in_device *in_dev = im->interface;
1154 #ifdef CONFIG_IP_MULTICAST
1155 	int reporter;
1156 #endif
1157 
1158 	if (im->loaded) {
1159 		im->loaded = 0;
1160 		ip_mc_filter_del(in_dev, im->multiaddr);
1161 	}
1162 
1163 #ifdef CONFIG_IP_MULTICAST
1164 	if (im->multiaddr == IGMP_ALL_HOSTS)
1165 		return;
1166 
1167 	reporter = im->reporter;
1168 	igmp_stop_timer(im);
1169 
1170 	if (!in_dev->dead) {
1171 		if (IGMP_V1_SEEN(in_dev))
1172 			return;
1173 		if (IGMP_V2_SEEN(in_dev)) {
1174 			if (reporter)
1175 				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
1176 			return;
1177 		}
1178 		/* IGMPv3 */
1179 		igmpv3_add_delrec(in_dev, im);
1180 
1181 		igmp_ifc_event(in_dev);
1182 	}
1183 #endif
1184 }
1185 
1186 static void igmp_group_added(struct ip_mc_list *im)
1187 {
1188 	struct in_device *in_dev = im->interface;
1189 
1190 	if (im->loaded == 0) {
1191 		im->loaded = 1;
1192 		ip_mc_filter_add(in_dev, im->multiaddr);
1193 	}
1194 
1195 #ifdef CONFIG_IP_MULTICAST
1196 	if (im->multiaddr == IGMP_ALL_HOSTS)
1197 		return;
1198 
1199 	if (in_dev->dead)
1200 		return;
1201 	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
1202 		spin_lock_bh(&im->lock);
1203 		igmp_start_timer(im, IGMP_Initial_Report_Delay);
1204 		spin_unlock_bh(&im->lock);
1205 		return;
1206 	}
1207 	/* else, v3 */
1208 
1209 	im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
1210 		IGMP_Unsolicited_Report_Count;
1211 	igmp_ifc_event(in_dev);
1212 #endif
1213 }
1214 
1215 
1216 /*
1217  *	Multicast list managers
1218  */
1219 
1220 static u32 ip_mc_hash(const struct ip_mc_list *im)
1221 {
1222 	return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
1223 }
1224 
1225 static void ip_mc_hash_add(struct in_device *in_dev,
1226 			   struct ip_mc_list *im)
1227 {
1228 	struct ip_mc_list __rcu **mc_hash;
1229 	u32 hash;
1230 
1231 	mc_hash = rtnl_dereference(in_dev->mc_hash);
1232 	if (mc_hash) {
1233 		hash = ip_mc_hash(im);
1234 		im->next_hash = mc_hash[hash];
1235 		rcu_assign_pointer(mc_hash[hash], im);
1236 		return;
1237 	}
1238 
1239 	/* do not use a hash table for small number of items */
1240 	if (in_dev->mc_count < 4)
1241 		return;
1242 
1243 	mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
1244 			  GFP_KERNEL);
1245 	if (!mc_hash)
1246 		return;
1247 
1248 	for_each_pmc_rtnl(in_dev, im) {
1249 		hash = ip_mc_hash(im);
1250 		im->next_hash = mc_hash[hash];
1251 		RCU_INIT_POINTER(mc_hash[hash], im);
1252 	}
1253 
1254 	rcu_assign_pointer(in_dev->mc_hash, mc_hash);
1255 }
1256 
1257 static void ip_mc_hash_remove(struct in_device *in_dev,
1258 			      struct ip_mc_list *im)
1259 {
1260 	struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
1261 	struct ip_mc_list *aux;
1262 
1263 	if (!mc_hash)
1264 		return;
1265 	mc_hash += ip_mc_hash(im);
1266 	while ((aux = rtnl_dereference(*mc_hash)) != im)
1267 		mc_hash = &aux->next_hash;
1268 	*mc_hash = im->next_hash;
1269 }
1270 
1271 
1272 /*
1273  *	A socket has joined a multicast group on device dev.
1274  */
1275 
1276 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
1277 {
1278 	struct ip_mc_list *im;
1279 
1280 	ASSERT_RTNL();
1281 
1282 	for_each_pmc_rtnl(in_dev, im) {
1283 		if (im->multiaddr == addr) {
1284 			im->users++;
1285 			ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, NULL, 0);
1286 			goto out;
1287 		}
1288 	}
1289 
1290 	im = kzalloc(sizeof(*im), GFP_KERNEL);
1291 	if (!im)
1292 		goto out;
1293 
1294 	im->users = 1;
1295 	im->interface = in_dev;
1296 	in_dev_hold(in_dev);
1297 	im->multiaddr = addr;
1298 	/* initial mode is (EX, empty) */
1299 	im->sfmode = MCAST_EXCLUDE;
1300 	im->sfcount[MCAST_EXCLUDE] = 1;
1301 	atomic_set(&im->refcnt, 1);
1302 	spin_lock_init(&im->lock);
1303 #ifdef CONFIG_IP_MULTICAST
1304 	setup_timer(&im->timer, &igmp_timer_expire, (unsigned long)im);
1305 	im->unsolicit_count = IGMP_Unsolicited_Report_Count;
1306 #endif
1307 
1308 	im->next_rcu = in_dev->mc_list;
1309 	in_dev->mc_count++;
1310 	rcu_assign_pointer(in_dev->mc_list, im);
1311 
1312 	ip_mc_hash_add(in_dev, im);
1313 
1314 #ifdef CONFIG_IP_MULTICAST
1315 	igmpv3_del_delrec(in_dev, im->multiaddr);
1316 #endif
1317 	igmp_group_added(im);
1318 	if (!in_dev->dead)
1319 		ip_rt_multicast_event(in_dev);
1320 out:
1321 	return;
1322 }
1323 EXPORT_SYMBOL(ip_mc_inc_group);
1324 
1325 /*
1326  *	Resend IGMP JOIN report; used for bonding.
1327  *	Called with rcu_read_lock()
1328  */
1329 void ip_mc_rejoin_groups(struct in_device *in_dev)
1330 {
1331 #ifdef CONFIG_IP_MULTICAST
1332 	struct ip_mc_list *im;
1333 	int type;
1334 
1335 	for_each_pmc_rcu(in_dev, im) {
1336 		if (im->multiaddr == IGMP_ALL_HOSTS)
1337 			continue;
1338 
1339 		/* a failover is happening and switches
1340 		 * must be notified immediately
1341 		 */
1342 		if (IGMP_V1_SEEN(in_dev))
1343 			type = IGMP_HOST_MEMBERSHIP_REPORT;
1344 		else if (IGMP_V2_SEEN(in_dev))
1345 			type = IGMPV2_HOST_MEMBERSHIP_REPORT;
1346 		else
1347 			type = IGMPV3_HOST_MEMBERSHIP_REPORT;
1348 		igmp_send_report(in_dev, im, type);
1349 	}
1350 #endif
1351 }
1352 EXPORT_SYMBOL(ip_mc_rejoin_groups);
1353 
1354 /*
1355  *	A socket has left a multicast group on device dev
1356  */
1357 
1358 void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
1359 {
1360 	struct ip_mc_list *i;
1361 	struct ip_mc_list __rcu **ip;
1362 
1363 	ASSERT_RTNL();
1364 
1365 	for (ip = &in_dev->mc_list;
1366 	     (i = rtnl_dereference(*ip)) != NULL;
1367 	     ip = &i->next_rcu) {
1368 		if (i->multiaddr == addr) {
1369 			if (--i->users == 0) {
1370 				ip_mc_hash_remove(in_dev, i);
1371 				*ip = i->next_rcu;
1372 				in_dev->mc_count--;
1373 				igmp_group_dropped(i);
1374 				ip_mc_clear_src(i);
1375 
1376 				if (!in_dev->dead)
1377 					ip_rt_multicast_event(in_dev);
1378 
1379 				ip_ma_put(i);
1380 				return;
1381 			}
1382 			break;
1383 		}
1384 	}
1385 }
1386 EXPORT_SYMBOL(ip_mc_dec_group);
1387 
1388 /* Device changing type */
1389 
1390 void ip_mc_unmap(struct in_device *in_dev)
1391 {
1392 	struct ip_mc_list *pmc;
1393 
1394 	ASSERT_RTNL();
1395 
1396 	for_each_pmc_rtnl(in_dev, pmc)
1397 		igmp_group_dropped(pmc);
1398 }
1399 
1400 void ip_mc_remap(struct in_device *in_dev)
1401 {
1402 	struct ip_mc_list *pmc;
1403 
1404 	ASSERT_RTNL();
1405 
1406 	for_each_pmc_rtnl(in_dev, pmc)
1407 		igmp_group_added(pmc);
1408 }
1409 
1410 /* Device going down */
1411 
1412 void ip_mc_down(struct in_device *in_dev)
1413 {
1414 	struct ip_mc_list *pmc;
1415 
1416 	ASSERT_RTNL();
1417 
1418 	for_each_pmc_rtnl(in_dev, pmc)
1419 		igmp_group_dropped(pmc);
1420 
1421 #ifdef CONFIG_IP_MULTICAST
1422 	in_dev->mr_ifc_count = 0;
1423 	if (del_timer(&in_dev->mr_ifc_timer))
1424 		__in_dev_put(in_dev);
1425 	in_dev->mr_gq_running = 0;
1426 	if (del_timer(&in_dev->mr_gq_timer))
1427 		__in_dev_put(in_dev);
1428 	igmpv3_clear_delrec(in_dev);
1429 #endif
1430 
1431 	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
1432 }
1433 
1434 void ip_mc_init_dev(struct in_device *in_dev)
1435 {
1436 	ASSERT_RTNL();
1437 
1438 #ifdef CONFIG_IP_MULTICAST
1439 	setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
1440 			(unsigned long)in_dev);
1441 	setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
1442 			(unsigned long)in_dev);
1443 	in_dev->mr_qrv = IGMP_Unsolicited_Report_Count;
1444 #endif
1445 
1446 	spin_lock_init(&in_dev->mc_tomb_lock);
1447 }
1448 
1449 /* Device going up */
1450 
1451 void ip_mc_up(struct in_device *in_dev)
1452 {
1453 	struct ip_mc_list *pmc;
1454 
1455 	ASSERT_RTNL();
1456 
1457 	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
1458 
1459 	for_each_pmc_rtnl(in_dev, pmc)
1460 		igmp_group_added(pmc);
1461 }
1462 
1463 /*
1464  *	Device is about to be destroyed: clean up.
1465  */
1466 
1467 void ip_mc_destroy_dev(struct in_device *in_dev)
1468 {
1469 	struct ip_mc_list *i;
1470 
1471 	ASSERT_RTNL();
1472 
1473 	/* Deactivate timers */
1474 	ip_mc_down(in_dev);
1475 
1476 	while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
1477 		in_dev->mc_list = i->next_rcu;
1478 		in_dev->mc_count--;
1479 
1480 		/* We've dropped the groups in ip_mc_down already */
1481 		ip_mc_clear_src(i);
1482 		ip_ma_put(i);
1483 	}
1484 }
1485 
1486 /* RTNL is locked */
1487 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1488 {
1489 	struct net_device *dev = NULL;
1490 	struct in_device *idev = NULL;
1491 
1492 	if (imr->imr_ifindex) {
1493 		idev = inetdev_by_index(net, imr->imr_ifindex);
1494 		return idev;
1495 	}
1496 	if (imr->imr_address.s_addr) {
1497 		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1498 		if (!dev)
1499 			return NULL;
1500 	}
1501 
1502 	if (!dev) {
1503 		struct rtable *rt = ip_route_output(net,
1504 						    imr->imr_multiaddr.s_addr,
1505 						    0, 0, 0);
1506 		if (!IS_ERR(rt)) {
1507 			dev = rt->dst.dev;
1508 			ip_rt_put(rt);
1509 		}
1510 	}
1511 	if (dev) {
1512 		imr->imr_ifindex = dev->ifindex;
1513 		idev = __in_dev_get_rtnl(dev);
1514 	}
1515 	return idev;
1516 }
1517 
1518 /*
1519  *	Join a socket to a group
1520  */
1521 int sysctl_igmp_max_memberships __read_mostly = IP_MAX_MEMBERSHIPS;
1522 int sysctl_igmp_max_msf __read_mostly = IP_MAX_MSF;
1523 
1524 
1525 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1526 	__be32 *psfsrc)
1527 {
1528 	struct ip_sf_list *psf, *psf_prev;
1529 	int rv = 0;
1530 
1531 	psf_prev = NULL;
1532 	for (psf=pmc->sources; psf; psf=psf->sf_next) {
1533 		if (psf->sf_inaddr == *psfsrc)
1534 			break;
1535 		psf_prev = psf;
1536 	}
1537 	if (!psf || psf->sf_count[sfmode] == 0) {
1538 		/* source filter not found, or count wrong =>  bug */
1539 		return -ESRCH;
1540 	}
1541 	psf->sf_count[sfmode]--;
1542 	if (psf->sf_count[sfmode] == 0) {
1543 		ip_rt_multicast_event(pmc->interface);
1544 	}
1545 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1546 #ifdef CONFIG_IP_MULTICAST
1547 		struct in_device *in_dev = pmc->interface;
1548 #endif
1549 
1550 		/* no more filters for this source */
1551 		if (psf_prev)
1552 			psf_prev->sf_next = psf->sf_next;
1553 		else
1554 			pmc->sources = psf->sf_next;
1555 #ifdef CONFIG_IP_MULTICAST
1556 		if (psf->sf_oldin &&
1557 		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1558 			psf->sf_crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
1559 				IGMP_Unsolicited_Report_Count;
1560 			psf->sf_next = pmc->tomb;
1561 			pmc->tomb = psf;
1562 			rv = 1;
1563 		} else
1564 #endif
1565 			kfree(psf);
1566 	}
1567 	return rv;
1568 }
1569 
1570 #ifndef CONFIG_IP_MULTICAST
1571 #define igmp_ifc_event(x)	do { } while (0)
1572 #endif
1573 
1574 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1575 			 int sfcount, __be32 *psfsrc, int delta)
1576 {
1577 	struct ip_mc_list *pmc;
1578 	int	changerec = 0;
1579 	int	i, err;
1580 
1581 	if (!in_dev)
1582 		return -ENODEV;
1583 	rcu_read_lock();
1584 	for_each_pmc_rcu(in_dev, pmc) {
1585 		if (*pmca == pmc->multiaddr)
1586 			break;
1587 	}
1588 	if (!pmc) {
1589 		/* MCA not found?? bug */
1590 		rcu_read_unlock();
1591 		return -ESRCH;
1592 	}
1593 	spin_lock_bh(&pmc->lock);
1594 	rcu_read_unlock();
1595 #ifdef CONFIG_IP_MULTICAST
1596 	sf_markstate(pmc);
1597 #endif
1598 	if (!delta) {
1599 		err = -EINVAL;
1600 		if (!pmc->sfcount[sfmode])
1601 			goto out_unlock;
1602 		pmc->sfcount[sfmode]--;
1603 	}
1604 	err = 0;
1605 	for (i=0; i<sfcount; i++) {
1606 		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1607 
1608 		changerec |= rv > 0;
1609 		if (!err && rv < 0)
1610 			err = rv;
1611 	}
1612 	if (pmc->sfmode == MCAST_EXCLUDE &&
1613 	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1614 	    pmc->sfcount[MCAST_INCLUDE]) {
1615 #ifdef CONFIG_IP_MULTICAST
1616 		struct ip_sf_list *psf;
1617 #endif
1618 
1619 		/* filter mode change */
1620 		pmc->sfmode = MCAST_INCLUDE;
1621 #ifdef CONFIG_IP_MULTICAST
1622 		pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
1623 			IGMP_Unsolicited_Report_Count;
1624 		in_dev->mr_ifc_count = pmc->crcount;
1625 		for (psf=pmc->sources; psf; psf = psf->sf_next)
1626 			psf->sf_crcount = 0;
1627 		igmp_ifc_event(pmc->interface);
1628 	} else if (sf_setstate(pmc) || changerec) {
1629 		igmp_ifc_event(pmc->interface);
1630 #endif
1631 	}
1632 out_unlock:
1633 	spin_unlock_bh(&pmc->lock);
1634 	return err;
1635 }
1636 
1637 /*
1638  * Add multicast single-source filter to the interface list
1639  */
1640 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1641 	__be32 *psfsrc)
1642 {
1643 	struct ip_sf_list *psf, *psf_prev;
1644 
1645 	psf_prev = NULL;
1646 	for (psf=pmc->sources; psf; psf=psf->sf_next) {
1647 		if (psf->sf_inaddr == *psfsrc)
1648 			break;
1649 		psf_prev = psf;
1650 	}
1651 	if (!psf) {
1652 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1653 		if (!psf)
1654 			return -ENOBUFS;
1655 		psf->sf_inaddr = *psfsrc;
1656 		if (psf_prev) {
1657 			psf_prev->sf_next = psf;
1658 		} else
1659 			pmc->sources = psf;
1660 	}
1661 	psf->sf_count[sfmode]++;
1662 	if (psf->sf_count[sfmode] == 1) {
1663 		ip_rt_multicast_event(pmc->interface);
1664 	}
1665 	return 0;
1666 }
1667 
1668 #ifdef CONFIG_IP_MULTICAST
1669 static void sf_markstate(struct ip_mc_list *pmc)
1670 {
1671 	struct ip_sf_list *psf;
1672 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1673 
1674 	for (psf=pmc->sources; psf; psf=psf->sf_next)
1675 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1676 			psf->sf_oldin = mca_xcount ==
1677 				psf->sf_count[MCAST_EXCLUDE] &&
1678 				!psf->sf_count[MCAST_INCLUDE];
1679 		} else
1680 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
1681 }
1682 
1683 static int sf_setstate(struct ip_mc_list *pmc)
1684 {
1685 	struct ip_sf_list *psf, *dpsf;
1686 	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1687 	int qrv = pmc->interface->mr_qrv;
1688 	int new_in, rv;
1689 
1690 	rv = 0;
1691 	for (psf=pmc->sources; psf; psf=psf->sf_next) {
1692 		if (pmc->sfcount[MCAST_EXCLUDE]) {
1693 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
1694 				!psf->sf_count[MCAST_INCLUDE];
1695 		} else
1696 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
1697 		if (new_in) {
1698 			if (!psf->sf_oldin) {
1699 				struct ip_sf_list *prev = NULL;
1700 
1701 				for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next) {
1702 					if (dpsf->sf_inaddr == psf->sf_inaddr)
1703 						break;
1704 					prev = dpsf;
1705 				}
1706 				if (dpsf) {
1707 					if (prev)
1708 						prev->sf_next = dpsf->sf_next;
1709 					else
1710 						pmc->tomb = dpsf->sf_next;
1711 					kfree(dpsf);
1712 				}
1713 				psf->sf_crcount = qrv;
1714 				rv++;
1715 			}
1716 		} else if (psf->sf_oldin) {
1717 
1718 			psf->sf_crcount = 0;
1719 			/*
1720 			 * add or update "delete" records if an active filter
1721 			 * is now inactive
1722 			 */
1723 			for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next)
1724 				if (dpsf->sf_inaddr == psf->sf_inaddr)
1725 					break;
1726 			if (!dpsf) {
1727 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
1728 				if (!dpsf)
1729 					continue;
1730 				*dpsf = *psf;
1731 				/* pmc->lock held by callers */
1732 				dpsf->sf_next = pmc->tomb;
1733 				pmc->tomb = dpsf;
1734 			}
1735 			dpsf->sf_crcount = qrv;
1736 			rv++;
1737 		}
1738 	}
1739 	return rv;
1740 }
1741 #endif
1742 
1743 /*
1744  * Add multicast source filter list to the interface list
1745  */
1746 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1747 			 int sfcount, __be32 *psfsrc, int delta)
1748 {
1749 	struct ip_mc_list *pmc;
1750 	int	isexclude;
1751 	int	i, err;
1752 
1753 	if (!in_dev)
1754 		return -ENODEV;
1755 	rcu_read_lock();
1756 	for_each_pmc_rcu(in_dev, pmc) {
1757 		if (*pmca == pmc->multiaddr)
1758 			break;
1759 	}
1760 	if (!pmc) {
1761 		/* MCA not found?? bug */
1762 		rcu_read_unlock();
1763 		return -ESRCH;
1764 	}
1765 	spin_lock_bh(&pmc->lock);
1766 	rcu_read_unlock();
1767 
1768 #ifdef CONFIG_IP_MULTICAST
1769 	sf_markstate(pmc);
1770 #endif
1771 	isexclude = pmc->sfmode == MCAST_EXCLUDE;
1772 	if (!delta)
1773 		pmc->sfcount[sfmode]++;
1774 	err = 0;
1775 	for (i=0; i<sfcount; i++) {
1776 		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
1777 		if (err)
1778 			break;
1779 	}
1780 	if (err) {
1781 		int j;
1782 
1783 		if (!delta)
1784 			pmc->sfcount[sfmode]--;
1785 		for (j=0; j<i; j++)
1786 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
1787 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
1788 #ifdef CONFIG_IP_MULTICAST
1789 		struct ip_sf_list *psf;
1790 		in_dev = pmc->interface;
1791 #endif
1792 
1793 		/* filter mode change */
1794 		if (pmc->sfcount[MCAST_EXCLUDE])
1795 			pmc->sfmode = MCAST_EXCLUDE;
1796 		else if (pmc->sfcount[MCAST_INCLUDE])
1797 			pmc->sfmode = MCAST_INCLUDE;
1798 #ifdef CONFIG_IP_MULTICAST
1799 		/* else no filters; keep old mode for reports */
1800 
1801 		pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
1802 			IGMP_Unsolicited_Report_Count;
1803 		in_dev->mr_ifc_count = pmc->crcount;
1804 		for (psf=pmc->sources; psf; psf = psf->sf_next)
1805 			psf->sf_crcount = 0;
1806 		igmp_ifc_event(in_dev);
1807 	} else if (sf_setstate(pmc)) {
1808 		igmp_ifc_event(in_dev);
1809 #endif
1810 	}
1811 	spin_unlock_bh(&pmc->lock);
1812 	return err;
1813 }
1814 
1815 static void ip_mc_clear_src(struct ip_mc_list *pmc)
1816 {
1817 	struct ip_sf_list *psf, *nextpsf;
1818 
1819 	for (psf=pmc->tomb; psf; psf=nextpsf) {
1820 		nextpsf = psf->sf_next;
1821 		kfree(psf);
1822 	}
1823 	pmc->tomb = NULL;
1824 	for (psf=pmc->sources; psf; psf=nextpsf) {
1825 		nextpsf = psf->sf_next;
1826 		kfree(psf);
1827 	}
1828 	pmc->sources = NULL;
1829 	pmc->sfmode = MCAST_EXCLUDE;
1830 	pmc->sfcount[MCAST_INCLUDE] = 0;
1831 	pmc->sfcount[MCAST_EXCLUDE] = 1;
1832 }
1833 
1834 
1835 /*
1836  * Join a multicast group
1837  */
1838 int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
1839 {
1840 	int err;
1841 	__be32 addr = imr->imr_multiaddr.s_addr;
1842 	struct ip_mc_socklist *iml = NULL, *i;
1843 	struct in_device *in_dev;
1844 	struct inet_sock *inet = inet_sk(sk);
1845 	struct net *net = sock_net(sk);
1846 	int ifindex;
1847 	int count = 0;
1848 
1849 	if (!ipv4_is_multicast(addr))
1850 		return -EINVAL;
1851 
1852 	rtnl_lock();
1853 
1854 	in_dev = ip_mc_find_dev(net, imr);
1855 
1856 	if (!in_dev) {
1857 		iml = NULL;
1858 		err = -ENODEV;
1859 		goto done;
1860 	}
1861 
1862 	err = -EADDRINUSE;
1863 	ifindex = imr->imr_ifindex;
1864 	for_each_pmc_rtnl(inet, i) {
1865 		if (i->multi.imr_multiaddr.s_addr == addr &&
1866 		    i->multi.imr_ifindex == ifindex)
1867 			goto done;
1868 		count++;
1869 	}
1870 	err = -ENOBUFS;
1871 	if (count >= sysctl_igmp_max_memberships)
1872 		goto done;
1873 	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
1874 	if (iml == NULL)
1875 		goto done;
1876 
1877 	memcpy(&iml->multi, imr, sizeof(*imr));
1878 	iml->next_rcu = inet->mc_list;
1879 	iml->sflist = NULL;
1880 	iml->sfmode = MCAST_EXCLUDE;
1881 	rcu_assign_pointer(inet->mc_list, iml);
1882 	ip_mc_inc_group(in_dev, addr);
1883 	err = 0;
1884 done:
1885 	rtnl_unlock();
1886 	return err;
1887 }
1888 EXPORT_SYMBOL(ip_mc_join_group);
1889 
1890 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
1891 			   struct in_device *in_dev)
1892 {
1893 	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
1894 	int err;
1895 
1896 	if (psf == NULL) {
1897 		/* any-source empty exclude case */
1898 		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
1899 			iml->sfmode, 0, NULL, 0);
1900 	}
1901 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
1902 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
1903 	RCU_INIT_POINTER(iml->sflist, NULL);
1904 	/* decrease mem now to avoid the memleak warning */
1905 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
1906 	kfree_rcu(psf, rcu);
1907 	return err;
1908 }
1909 
1910 /*
1911  *	Ask a socket to leave a group.
1912  */
1913 
1914 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
1915 {
1916 	struct inet_sock *inet = inet_sk(sk);
1917 	struct ip_mc_socklist *iml;
1918 	struct ip_mc_socklist __rcu **imlp;
1919 	struct in_device *in_dev;
1920 	struct net *net = sock_net(sk);
1921 	__be32 group = imr->imr_multiaddr.s_addr;
1922 	u32 ifindex;
1923 	int ret = -EADDRNOTAVAIL;
1924 
1925 	rtnl_lock();
1926 	in_dev = ip_mc_find_dev(net, imr);
1927 	ifindex = imr->imr_ifindex;
1928 	for (imlp = &inet->mc_list;
1929 	     (iml = rtnl_dereference(*imlp)) != NULL;
1930 	     imlp = &iml->next_rcu) {
1931 		if (iml->multi.imr_multiaddr.s_addr != group)
1932 			continue;
1933 		if (ifindex) {
1934 			if (iml->multi.imr_ifindex != ifindex)
1935 				continue;
1936 		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
1937 				iml->multi.imr_address.s_addr)
1938 			continue;
1939 
1940 		(void) ip_mc_leave_src(sk, iml, in_dev);
1941 
1942 		*imlp = iml->next_rcu;
1943 
1944 		if (in_dev)
1945 			ip_mc_dec_group(in_dev, group);
1946 		rtnl_unlock();
1947 		/* decrease mem now to avoid the memleak warning */
1948 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
1949 		kfree_rcu(iml, rcu);
1950 		return 0;
1951 	}
1952 	if (!in_dev)
1953 		ret = -ENODEV;
1954 	rtnl_unlock();
1955 	return ret;
1956 }
1957 EXPORT_SYMBOL(ip_mc_leave_group);
1958 
1959 int ip_mc_source(int add, int omode, struct sock *sk, struct
1960 	ip_mreq_source *mreqs, int ifindex)
1961 {
1962 	int err;
1963 	struct ip_mreqn imr;
1964 	__be32 addr = mreqs->imr_multiaddr;
1965 	struct ip_mc_socklist *pmc;
1966 	struct in_device *in_dev = NULL;
1967 	struct inet_sock *inet = inet_sk(sk);
1968 	struct ip_sf_socklist *psl;
1969 	struct net *net = sock_net(sk);
1970 	int leavegroup = 0;
1971 	int i, j, rv;
1972 
1973 	if (!ipv4_is_multicast(addr))
1974 		return -EINVAL;
1975 
1976 	rtnl_lock();
1977 
1978 	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
1979 	imr.imr_address.s_addr = mreqs->imr_interface;
1980 	imr.imr_ifindex = ifindex;
1981 	in_dev = ip_mc_find_dev(net, &imr);
1982 
1983 	if (!in_dev) {
1984 		err = -ENODEV;
1985 		goto done;
1986 	}
1987 	err = -EADDRNOTAVAIL;
1988 
1989 	for_each_pmc_rtnl(inet, pmc) {
1990 		if ((pmc->multi.imr_multiaddr.s_addr ==
1991 		     imr.imr_multiaddr.s_addr) &&
1992 		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
1993 			break;
1994 	}
1995 	if (!pmc) {		/* must have a prior join */
1996 		err = -EINVAL;
1997 		goto done;
1998 	}
1999 	/* if a source filter was set, must be the same mode as before */
2000 	if (pmc->sflist) {
2001 		if (pmc->sfmode != omode) {
2002 			err = -EINVAL;
2003 			goto done;
2004 		}
2005 	} else if (pmc->sfmode != omode) {
2006 		/* allow mode switches for empty-set filters */
2007 		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2008 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2009 			NULL, 0);
2010 		pmc->sfmode = omode;
2011 	}
2012 
2013 	psl = rtnl_dereference(pmc->sflist);
2014 	if (!add) {
2015 		if (!psl)
2016 			goto done;	/* err = -EADDRNOTAVAIL */
2017 		rv = !0;
2018 		for (i=0; i<psl->sl_count; i++) {
2019 			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2020 				sizeof(__be32));
2021 			if (rv == 0)
2022 				break;
2023 		}
2024 		if (rv)		/* source not found */
2025 			goto done;	/* err = -EADDRNOTAVAIL */
2026 
2027 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2028 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2029 			leavegroup = 1;
2030 			goto done;
2031 		}
2032 
2033 		/* update the interface filter */
2034 		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2035 			&mreqs->imr_sourceaddr, 1);
2036 
2037 		for (j=i+1; j<psl->sl_count; j++)
2038 			psl->sl_addr[j-1] = psl->sl_addr[j];
2039 		psl->sl_count--;
2040 		err = 0;
2041 		goto done;
2042 	}
2043 	/* else, add a new source to the filter */
2044 
2045 	if (psl && psl->sl_count >= sysctl_igmp_max_msf) {
2046 		err = -ENOBUFS;
2047 		goto done;
2048 	}
2049 	if (!psl || psl->sl_count == psl->sl_max) {
2050 		struct ip_sf_socklist *newpsl;
2051 		int count = IP_SFBLOCK;
2052 
2053 		if (psl)
2054 			count += psl->sl_max;
2055 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2056 		if (!newpsl) {
2057 			err = -ENOBUFS;
2058 			goto done;
2059 		}
2060 		newpsl->sl_max = count;
2061 		newpsl->sl_count = count - IP_SFBLOCK;
2062 		if (psl) {
2063 			for (i=0; i<psl->sl_count; i++)
2064 				newpsl->sl_addr[i] = psl->sl_addr[i];
2065 			/* decrease mem now to avoid the memleak warning */
2066 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2067 			kfree_rcu(psl, rcu);
2068 		}
2069 		rcu_assign_pointer(pmc->sflist, newpsl);
2070 		psl = newpsl;
2071 	}
2072 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
2073 	for (i=0; i<psl->sl_count; i++) {
2074 		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2075 			sizeof(__be32));
2076 		if (rv == 0)
2077 			break;
2078 	}
2079 	if (rv == 0)		/* address already there is an error */
2080 		goto done;
2081 	for (j=psl->sl_count-1; j>=i; j--)
2082 		psl->sl_addr[j+1] = psl->sl_addr[j];
2083 	psl->sl_addr[i] = mreqs->imr_sourceaddr;
2084 	psl->sl_count++;
2085 	err = 0;
2086 	/* update the interface list */
2087 	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2088 		&mreqs->imr_sourceaddr, 1);
2089 done:
2090 	rtnl_unlock();
2091 	if (leavegroup)
2092 		return ip_mc_leave_group(sk, &imr);
2093 	return err;
2094 }
2095 
2096 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2097 {
2098 	int err = 0;
2099 	struct ip_mreqn	imr;
2100 	__be32 addr = msf->imsf_multiaddr;
2101 	struct ip_mc_socklist *pmc;
2102 	struct in_device *in_dev;
2103 	struct inet_sock *inet = inet_sk(sk);
2104 	struct ip_sf_socklist *newpsl, *psl;
2105 	struct net *net = sock_net(sk);
2106 	int leavegroup = 0;
2107 
2108 	if (!ipv4_is_multicast(addr))
2109 		return -EINVAL;
2110 	if (msf->imsf_fmode != MCAST_INCLUDE &&
2111 	    msf->imsf_fmode != MCAST_EXCLUDE)
2112 		return -EINVAL;
2113 
2114 	rtnl_lock();
2115 
2116 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2117 	imr.imr_address.s_addr = msf->imsf_interface;
2118 	imr.imr_ifindex = ifindex;
2119 	in_dev = ip_mc_find_dev(net, &imr);
2120 
2121 	if (!in_dev) {
2122 		err = -ENODEV;
2123 		goto done;
2124 	}
2125 
2126 	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
2127 	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2128 		leavegroup = 1;
2129 		goto done;
2130 	}
2131 
2132 	for_each_pmc_rtnl(inet, pmc) {
2133 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2134 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2135 			break;
2136 	}
2137 	if (!pmc) {		/* must have a prior join */
2138 		err = -EINVAL;
2139 		goto done;
2140 	}
2141 	if (msf->imsf_numsrc) {
2142 		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2143 							   GFP_KERNEL);
2144 		if (!newpsl) {
2145 			err = -ENOBUFS;
2146 			goto done;
2147 		}
2148 		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2149 		memcpy(newpsl->sl_addr, msf->imsf_slist,
2150 			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2151 		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2152 			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2153 		if (err) {
2154 			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2155 			goto done;
2156 		}
2157 	} else {
2158 		newpsl = NULL;
2159 		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2160 				     msf->imsf_fmode, 0, NULL, 0);
2161 	}
2162 	psl = rtnl_dereference(pmc->sflist);
2163 	if (psl) {
2164 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2165 			psl->sl_count, psl->sl_addr, 0);
2166 		/* decrease mem now to avoid the memleak warning */
2167 		atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2168 		kfree_rcu(psl, rcu);
2169 	} else
2170 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2171 			0, NULL, 0);
2172 	rcu_assign_pointer(pmc->sflist, newpsl);
2173 	pmc->sfmode = msf->imsf_fmode;
2174 	err = 0;
2175 done:
2176 	rtnl_unlock();
2177 	if (leavegroup)
2178 		err = ip_mc_leave_group(sk, &imr);
2179 	return err;
2180 }
2181 
2182 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2183 	struct ip_msfilter __user *optval, int __user *optlen)
2184 {
2185 	int err, len, count, copycount;
2186 	struct ip_mreqn	imr;
2187 	__be32 addr = msf->imsf_multiaddr;
2188 	struct ip_mc_socklist *pmc;
2189 	struct in_device *in_dev;
2190 	struct inet_sock *inet = inet_sk(sk);
2191 	struct ip_sf_socklist *psl;
2192 	struct net *net = sock_net(sk);
2193 
2194 	if (!ipv4_is_multicast(addr))
2195 		return -EINVAL;
2196 
2197 	rtnl_lock();
2198 
2199 	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2200 	imr.imr_address.s_addr = msf->imsf_interface;
2201 	imr.imr_ifindex = 0;
2202 	in_dev = ip_mc_find_dev(net, &imr);
2203 
2204 	if (!in_dev) {
2205 		err = -ENODEV;
2206 		goto done;
2207 	}
2208 	err = -EADDRNOTAVAIL;
2209 
2210 	for_each_pmc_rtnl(inet, pmc) {
2211 		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2212 		    pmc->multi.imr_ifindex == imr.imr_ifindex)
2213 			break;
2214 	}
2215 	if (!pmc)		/* must have a prior join */
2216 		goto done;
2217 	msf->imsf_fmode = pmc->sfmode;
2218 	psl = rtnl_dereference(pmc->sflist);
2219 	rtnl_unlock();
2220 	if (!psl) {
2221 		len = 0;
2222 		count = 0;
2223 	} else {
2224 		count = psl->sl_count;
2225 	}
2226 	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2227 	len = copycount * sizeof(psl->sl_addr[0]);
2228 	msf->imsf_numsrc = count;
2229 	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2230 	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2231 		return -EFAULT;
2232 	}
2233 	if (len &&
2234 	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2235 		return -EFAULT;
2236 	return 0;
2237 done:
2238 	rtnl_unlock();
2239 	return err;
2240 }
2241 
2242 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2243 	struct group_filter __user *optval, int __user *optlen)
2244 {
2245 	int err, i, count, copycount;
2246 	struct sockaddr_in *psin;
2247 	__be32 addr;
2248 	struct ip_mc_socklist *pmc;
2249 	struct inet_sock *inet = inet_sk(sk);
2250 	struct ip_sf_socklist *psl;
2251 
2252 	psin = (struct sockaddr_in *)&gsf->gf_group;
2253 	if (psin->sin_family != AF_INET)
2254 		return -EINVAL;
2255 	addr = psin->sin_addr.s_addr;
2256 	if (!ipv4_is_multicast(addr))
2257 		return -EINVAL;
2258 
2259 	rtnl_lock();
2260 
2261 	err = -EADDRNOTAVAIL;
2262 
2263 	for_each_pmc_rtnl(inet, pmc) {
2264 		if (pmc->multi.imr_multiaddr.s_addr == addr &&
2265 		    pmc->multi.imr_ifindex == gsf->gf_interface)
2266 			break;
2267 	}
2268 	if (!pmc)		/* must have a prior join */
2269 		goto done;
2270 	gsf->gf_fmode = pmc->sfmode;
2271 	psl = rtnl_dereference(pmc->sflist);
2272 	rtnl_unlock();
2273 	count = psl ? psl->sl_count : 0;
2274 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2275 	gsf->gf_numsrc = count;
2276 	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
2277 	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
2278 		return -EFAULT;
2279 	}
2280 	for (i=0; i<copycount; i++) {
2281 		struct sockaddr_storage ss;
2282 
2283 		psin = (struct sockaddr_in *)&ss;
2284 		memset(&ss, 0, sizeof(ss));
2285 		psin->sin_family = AF_INET;
2286 		psin->sin_addr.s_addr = psl->sl_addr[i];
2287 		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
2288 			return -EFAULT;
2289 	}
2290 	return 0;
2291 done:
2292 	rtnl_unlock();
2293 	return err;
2294 }
2295 
2296 /*
2297  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2298  */
2299 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
2300 {
2301 	struct inet_sock *inet = inet_sk(sk);
2302 	struct ip_mc_socklist *pmc;
2303 	struct ip_sf_socklist *psl;
2304 	int i;
2305 	int ret;
2306 
2307 	ret = 1;
2308 	if (!ipv4_is_multicast(loc_addr))
2309 		goto out;
2310 
2311 	rcu_read_lock();
2312 	for_each_pmc_rcu(inet, pmc) {
2313 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2314 		    pmc->multi.imr_ifindex == dif)
2315 			break;
2316 	}
2317 	ret = inet->mc_all;
2318 	if (!pmc)
2319 		goto unlock;
2320 	psl = rcu_dereference(pmc->sflist);
2321 	ret = (pmc->sfmode == MCAST_EXCLUDE);
2322 	if (!psl)
2323 		goto unlock;
2324 
2325 	for (i=0; i<psl->sl_count; i++) {
2326 		if (psl->sl_addr[i] == rmt_addr)
2327 			break;
2328 	}
2329 	ret = 0;
2330 	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2331 		goto unlock;
2332 	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2333 		goto unlock;
2334 	ret = 1;
2335 unlock:
2336 	rcu_read_unlock();
2337 out:
2338 	return ret;
2339 }
2340 
2341 /*
2342  *	A socket is closing.
2343  */
2344 
2345 void ip_mc_drop_socket(struct sock *sk)
2346 {
2347 	struct inet_sock *inet = inet_sk(sk);
2348 	struct ip_mc_socklist *iml;
2349 	struct net *net = sock_net(sk);
2350 
2351 	if (inet->mc_list == NULL)
2352 		return;
2353 
2354 	rtnl_lock();
2355 	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2356 		struct in_device *in_dev;
2357 
2358 		inet->mc_list = iml->next_rcu;
2359 		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2360 		(void) ip_mc_leave_src(sk, iml, in_dev);
2361 		if (in_dev != NULL)
2362 			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2363 		/* decrease mem now to avoid the memleak warning */
2364 		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2365 		kfree_rcu(iml, rcu);
2366 	}
2367 	rtnl_unlock();
2368 }
2369 
2370 /* called with rcu_read_lock() */
2371 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)
2372 {
2373 	struct ip_mc_list *im;
2374 	struct ip_mc_list __rcu **mc_hash;
2375 	struct ip_sf_list *psf;
2376 	int rv = 0;
2377 
2378 	mc_hash = rcu_dereference(in_dev->mc_hash);
2379 	if (mc_hash) {
2380 		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2381 
2382 		for (im = rcu_dereference(mc_hash[hash]);
2383 		     im != NULL;
2384 		     im = rcu_dereference(im->next_hash)) {
2385 			if (im->multiaddr == mc_addr)
2386 				break;
2387 		}
2388 	} else {
2389 		for_each_pmc_rcu(in_dev, im) {
2390 			if (im->multiaddr == mc_addr)
2391 				break;
2392 		}
2393 	}
2394 	if (im && proto == IPPROTO_IGMP) {
2395 		rv = 1;
2396 	} else if (im) {
2397 		if (src_addr) {
2398 			for (psf=im->sources; psf; psf=psf->sf_next) {
2399 				if (psf->sf_inaddr == src_addr)
2400 					break;
2401 			}
2402 			if (psf)
2403 				rv = psf->sf_count[MCAST_INCLUDE] ||
2404 					psf->sf_count[MCAST_EXCLUDE] !=
2405 					im->sfcount[MCAST_EXCLUDE];
2406 			else
2407 				rv = im->sfcount[MCAST_EXCLUDE] != 0;
2408 		} else
2409 			rv = 1; /* unspecified source; tentatively allow */
2410 	}
2411 	return rv;
2412 }
2413 
2414 #if defined(CONFIG_PROC_FS)
2415 struct igmp_mc_iter_state {
2416 	struct seq_net_private p;
2417 	struct net_device *dev;
2418 	struct in_device *in_dev;
2419 };
2420 
2421 #define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
2422 
2423 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2424 {
2425 	struct net *net = seq_file_net(seq);
2426 	struct ip_mc_list *im = NULL;
2427 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2428 
2429 	state->in_dev = NULL;
2430 	for_each_netdev_rcu(net, state->dev) {
2431 		struct in_device *in_dev;
2432 
2433 		in_dev = __in_dev_get_rcu(state->dev);
2434 		if (!in_dev)
2435 			continue;
2436 		im = rcu_dereference(in_dev->mc_list);
2437 		if (im) {
2438 			state->in_dev = in_dev;
2439 			break;
2440 		}
2441 	}
2442 	return im;
2443 }
2444 
2445 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2446 {
2447 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2448 
2449 	im = rcu_dereference(im->next_rcu);
2450 	while (!im) {
2451 		state->dev = next_net_device_rcu(state->dev);
2452 		if (!state->dev) {
2453 			state->in_dev = NULL;
2454 			break;
2455 		}
2456 		state->in_dev = __in_dev_get_rcu(state->dev);
2457 		if (!state->in_dev)
2458 			continue;
2459 		im = rcu_dereference(state->in_dev->mc_list);
2460 	}
2461 	return im;
2462 }
2463 
2464 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2465 {
2466 	struct ip_mc_list *im = igmp_mc_get_first(seq);
2467 	if (im)
2468 		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2469 			--pos;
2470 	return pos ? NULL : im;
2471 }
2472 
2473 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2474 	__acquires(rcu)
2475 {
2476 	rcu_read_lock();
2477 	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2478 }
2479 
2480 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2481 {
2482 	struct ip_mc_list *im;
2483 	if (v == SEQ_START_TOKEN)
2484 		im = igmp_mc_get_first(seq);
2485 	else
2486 		im = igmp_mc_get_next(seq, v);
2487 	++*pos;
2488 	return im;
2489 }
2490 
2491 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2492 	__releases(rcu)
2493 {
2494 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2495 
2496 	state->in_dev = NULL;
2497 	state->dev = NULL;
2498 	rcu_read_unlock();
2499 }
2500 
2501 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2502 {
2503 	if (v == SEQ_START_TOKEN)
2504 		seq_puts(seq,
2505 			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2506 	else {
2507 		struct ip_mc_list *im = (struct ip_mc_list *)v;
2508 		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2509 		char   *querier;
2510 		long delta;
2511 
2512 #ifdef CONFIG_IP_MULTICAST
2513 		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2514 			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
2515 			  "V3";
2516 #else
2517 		querier = "NONE";
2518 #endif
2519 
2520 		if (rcu_dereference(state->in_dev->mc_list) == im) {
2521 			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2522 				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2523 		}
2524 
2525 		delta = im->timer.expires - jiffies;
2526 		seq_printf(seq,
2527 			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2528 			   im->multiaddr, im->users,
2529 			   im->tm_running,
2530 			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2531 			   im->reporter);
2532 	}
2533 	return 0;
2534 }
2535 
2536 static const struct seq_operations igmp_mc_seq_ops = {
2537 	.start	=	igmp_mc_seq_start,
2538 	.next	=	igmp_mc_seq_next,
2539 	.stop	=	igmp_mc_seq_stop,
2540 	.show	=	igmp_mc_seq_show,
2541 };
2542 
2543 static int igmp_mc_seq_open(struct inode *inode, struct file *file)
2544 {
2545 	return seq_open_net(inode, file, &igmp_mc_seq_ops,
2546 			sizeof(struct igmp_mc_iter_state));
2547 }
2548 
2549 static const struct file_operations igmp_mc_seq_fops = {
2550 	.owner		=	THIS_MODULE,
2551 	.open		=	igmp_mc_seq_open,
2552 	.read		=	seq_read,
2553 	.llseek		=	seq_lseek,
2554 	.release	=	seq_release_net,
2555 };
2556 
2557 struct igmp_mcf_iter_state {
2558 	struct seq_net_private p;
2559 	struct net_device *dev;
2560 	struct in_device *idev;
2561 	struct ip_mc_list *im;
2562 };
2563 
2564 #define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
2565 
2566 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2567 {
2568 	struct net *net = seq_file_net(seq);
2569 	struct ip_sf_list *psf = NULL;
2570 	struct ip_mc_list *im = NULL;
2571 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2572 
2573 	state->idev = NULL;
2574 	state->im = NULL;
2575 	for_each_netdev_rcu(net, state->dev) {
2576 		struct in_device *idev;
2577 		idev = __in_dev_get_rcu(state->dev);
2578 		if (unlikely(idev == NULL))
2579 			continue;
2580 		im = rcu_dereference(idev->mc_list);
2581 		if (likely(im != NULL)) {
2582 			spin_lock_bh(&im->lock);
2583 			psf = im->sources;
2584 			if (likely(psf != NULL)) {
2585 				state->im = im;
2586 				state->idev = idev;
2587 				break;
2588 			}
2589 			spin_unlock_bh(&im->lock);
2590 		}
2591 	}
2592 	return psf;
2593 }
2594 
2595 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2596 {
2597 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2598 
2599 	psf = psf->sf_next;
2600 	while (!psf) {
2601 		spin_unlock_bh(&state->im->lock);
2602 		state->im = state->im->next;
2603 		while (!state->im) {
2604 			state->dev = next_net_device_rcu(state->dev);
2605 			if (!state->dev) {
2606 				state->idev = NULL;
2607 				goto out;
2608 			}
2609 			state->idev = __in_dev_get_rcu(state->dev);
2610 			if (!state->idev)
2611 				continue;
2612 			state->im = rcu_dereference(state->idev->mc_list);
2613 		}
2614 		if (!state->im)
2615 			break;
2616 		spin_lock_bh(&state->im->lock);
2617 		psf = state->im->sources;
2618 	}
2619 out:
2620 	return psf;
2621 }
2622 
2623 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2624 {
2625 	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2626 	if (psf)
2627 		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2628 			--pos;
2629 	return pos ? NULL : psf;
2630 }
2631 
2632 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2633 	__acquires(rcu)
2634 {
2635 	rcu_read_lock();
2636 	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2637 }
2638 
2639 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2640 {
2641 	struct ip_sf_list *psf;
2642 	if (v == SEQ_START_TOKEN)
2643 		psf = igmp_mcf_get_first(seq);
2644 	else
2645 		psf = igmp_mcf_get_next(seq, v);
2646 	++*pos;
2647 	return psf;
2648 }
2649 
2650 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2651 	__releases(rcu)
2652 {
2653 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2654 	if (likely(state->im != NULL)) {
2655 		spin_unlock_bh(&state->im->lock);
2656 		state->im = NULL;
2657 	}
2658 	state->idev = NULL;
2659 	state->dev = NULL;
2660 	rcu_read_unlock();
2661 }
2662 
2663 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2664 {
2665 	struct ip_sf_list *psf = (struct ip_sf_list *)v;
2666 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2667 
2668 	if (v == SEQ_START_TOKEN) {
2669 		seq_printf(seq,
2670 			   "%3s %6s "
2671 			   "%10s %10s %6s %6s\n", "Idx",
2672 			   "Device", "MCA",
2673 			   "SRC", "INC", "EXC");
2674 	} else {
2675 		seq_printf(seq,
2676 			   "%3d %6.6s 0x%08x "
2677 			   "0x%08x %6lu %6lu\n",
2678 			   state->dev->ifindex, state->dev->name,
2679 			   ntohl(state->im->multiaddr),
2680 			   ntohl(psf->sf_inaddr),
2681 			   psf->sf_count[MCAST_INCLUDE],
2682 			   psf->sf_count[MCAST_EXCLUDE]);
2683 	}
2684 	return 0;
2685 }
2686 
2687 static const struct seq_operations igmp_mcf_seq_ops = {
2688 	.start	=	igmp_mcf_seq_start,
2689 	.next	=	igmp_mcf_seq_next,
2690 	.stop	=	igmp_mcf_seq_stop,
2691 	.show	=	igmp_mcf_seq_show,
2692 };
2693 
2694 static int igmp_mcf_seq_open(struct inode *inode, struct file *file)
2695 {
2696 	return seq_open_net(inode, file, &igmp_mcf_seq_ops,
2697 			sizeof(struct igmp_mcf_iter_state));
2698 }
2699 
2700 static const struct file_operations igmp_mcf_seq_fops = {
2701 	.owner		=	THIS_MODULE,
2702 	.open		=	igmp_mcf_seq_open,
2703 	.read		=	seq_read,
2704 	.llseek		=	seq_lseek,
2705 	.release	=	seq_release_net,
2706 };
2707 
2708 static int __net_init igmp_net_init(struct net *net)
2709 {
2710 	struct proc_dir_entry *pde;
2711 
2712 	pde = proc_create("igmp", S_IRUGO, net->proc_net, &igmp_mc_seq_fops);
2713 	if (!pde)
2714 		goto out_igmp;
2715 	pde = proc_create("mcfilter", S_IRUGO, net->proc_net,
2716 			  &igmp_mcf_seq_fops);
2717 	if (!pde)
2718 		goto out_mcfilter;
2719 	return 0;
2720 
2721 out_mcfilter:
2722 	remove_proc_entry("igmp", net->proc_net);
2723 out_igmp:
2724 	return -ENOMEM;
2725 }
2726 
2727 static void __net_exit igmp_net_exit(struct net *net)
2728 {
2729 	remove_proc_entry("mcfilter", net->proc_net);
2730 	remove_proc_entry("igmp", net->proc_net);
2731 }
2732 
2733 static struct pernet_operations igmp_net_ops = {
2734 	.init = igmp_net_init,
2735 	.exit = igmp_net_exit,
2736 };
2737 
2738 int __init igmp_mc_proc_init(void)
2739 {
2740 	return register_pernet_subsys(&igmp_net_ops);
2741 }
2742 #endif
2743