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Linux/net/ipv4/igmp.c

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  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 #ifdef CONFIG_IP_MULTICAST
111 /* Parameter names and values are taken from igmp-v2-06 draft */
112 
113 #define IGMP_V1_ROUTER_PRESENT_TIMEOUT          (400*HZ)
114 #define IGMP_V2_ROUTER_PRESENT_TIMEOUT          (400*HZ)
115 #define IGMP_V2_UNSOLICITED_REPORT_INTERVAL     (10*HZ)
116 #define IGMP_V3_UNSOLICITED_REPORT_INTERVAL     (1*HZ)
117 #define IGMP_QUERY_RESPONSE_INTERVAL            (10*HZ)
118 #define IGMP_QUERY_ROBUSTNESS_VARIABLE          2
119 
120 
121 #define IGMP_INITIAL_REPORT_DELAY               (1)
122 
123 /* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
124  * IGMP specs require to report membership immediately after
125  * joining a group, but we delay the first report by a
126  * small interval. It seems more natural and still does not
127  * contradict to specs provided this delay is small enough.
128  */
129 
130 #define IGMP_V1_SEEN(in_dev) \
131         (IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
132          IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
133          ((in_dev)->mr_v1_seen && \
134           time_before(jiffies, (in_dev)->mr_v1_seen)))
135 #define IGMP_V2_SEEN(in_dev) \
136         (IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
137          IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
138          ((in_dev)->mr_v2_seen && \
139           time_before(jiffies, (in_dev)->mr_v2_seen)))
140 
141 static int unsolicited_report_interval(struct in_device *in_dev)
142 {
143         int interval_ms, interval_jiffies;
144 
145         if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
146                 interval_ms = IN_DEV_CONF_GET(
147                         in_dev,
148                         IGMPV2_UNSOLICITED_REPORT_INTERVAL);
149         else /* v3 */
150                 interval_ms = IN_DEV_CONF_GET(
151                         in_dev,
152                         IGMPV3_UNSOLICITED_REPORT_INTERVAL);
153 
154         interval_jiffies = msecs_to_jiffies(interval_ms);
155 
156         /* _timer functions can't handle a delay of 0 jiffies so ensure
157          *  we always return a positive value.
158          */
159         if (interval_jiffies <= 0)
160                 interval_jiffies = 1;
161         return interval_jiffies;
162 }
163 
164 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
165 static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr);
166 static void igmpv3_clear_delrec(struct in_device *in_dev);
167 static int sf_setstate(struct ip_mc_list *pmc);
168 static void sf_markstate(struct ip_mc_list *pmc);
169 #endif
170 static void ip_mc_clear_src(struct ip_mc_list *pmc);
171 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
172                          int sfcount, __be32 *psfsrc, int delta);
173 
174 static void ip_ma_put(struct ip_mc_list *im)
175 {
176         if (atomic_dec_and_test(&im->refcnt)) {
177                 in_dev_put(im->interface);
178                 kfree_rcu(im, rcu);
179         }
180 }
181 
182 #define for_each_pmc_rcu(in_dev, pmc)                           \
183         for (pmc = rcu_dereference(in_dev->mc_list);            \
184              pmc != NULL;                                       \
185              pmc = rcu_dereference(pmc->next_rcu))
186 
187 #define for_each_pmc_rtnl(in_dev, pmc)                          \
188         for (pmc = rtnl_dereference(in_dev->mc_list);           \
189              pmc != NULL;                                       \
190              pmc = rtnl_dereference(pmc->next_rcu))
191 
192 #ifdef CONFIG_IP_MULTICAST
193 
194 /*
195  *      Timer management
196  */
197 
198 static void igmp_stop_timer(struct ip_mc_list *im)
199 {
200         spin_lock_bh(&im->lock);
201         if (del_timer(&im->timer))
202                 atomic_dec(&im->refcnt);
203         im->tm_running = 0;
204         im->reporter = 0;
205         im->unsolicit_count = 0;
206         spin_unlock_bh(&im->lock);
207 }
208 
209 /* It must be called with locked im->lock */
210 static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
211 {
212         int tv = prandom_u32() % max_delay;
213 
214         im->tm_running = 1;
215         if (!mod_timer(&im->timer, jiffies+tv+2))
216                 atomic_inc(&im->refcnt);
217 }
218 
219 static void igmp_gq_start_timer(struct in_device *in_dev)
220 {
221         int tv = prandom_u32() % in_dev->mr_maxdelay;
222 
223         in_dev->mr_gq_running = 1;
224         if (!mod_timer(&in_dev->mr_gq_timer, jiffies+tv+2))
225                 in_dev_hold(in_dev);
226 }
227 
228 static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
229 {
230         int tv = prandom_u32() % delay;
231 
232         if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
233                 in_dev_hold(in_dev);
234 }
235 
236 static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
237 {
238         spin_lock_bh(&im->lock);
239         im->unsolicit_count = 0;
240         if (del_timer(&im->timer)) {
241                 if ((long)(im->timer.expires-jiffies) < max_delay) {
242                         add_timer(&im->timer);
243                         im->tm_running = 1;
244                         spin_unlock_bh(&im->lock);
245                         return;
246                 }
247                 atomic_dec(&im->refcnt);
248         }
249         igmp_start_timer(im, max_delay);
250         spin_unlock_bh(&im->lock);
251 }
252 
253 
254 /*
255  *      Send an IGMP report.
256  */
257 
258 #define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
259 
260 
261 static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
262         int gdeleted, int sdeleted)
263 {
264         switch (type) {
265         case IGMPV3_MODE_IS_INCLUDE:
266         case IGMPV3_MODE_IS_EXCLUDE:
267                 if (gdeleted || sdeleted)
268                         return 0;
269                 if (!(pmc->gsquery && !psf->sf_gsresp)) {
270                         if (pmc->sfmode == MCAST_INCLUDE)
271                                 return 1;
272                         /* don't include if this source is excluded
273                          * in all filters
274                          */
275                         if (psf->sf_count[MCAST_INCLUDE])
276                                 return type == IGMPV3_MODE_IS_INCLUDE;
277                         return pmc->sfcount[MCAST_EXCLUDE] ==
278                                 psf->sf_count[MCAST_EXCLUDE];
279                 }
280                 return 0;
281         case IGMPV3_CHANGE_TO_INCLUDE:
282                 if (gdeleted || sdeleted)
283                         return 0;
284                 return psf->sf_count[MCAST_INCLUDE] != 0;
285         case IGMPV3_CHANGE_TO_EXCLUDE:
286                 if (gdeleted || sdeleted)
287                         return 0;
288                 if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
289                     psf->sf_count[MCAST_INCLUDE])
290                         return 0;
291                 return pmc->sfcount[MCAST_EXCLUDE] ==
292                         psf->sf_count[MCAST_EXCLUDE];
293         case IGMPV3_ALLOW_NEW_SOURCES:
294                 if (gdeleted || !psf->sf_crcount)
295                         return 0;
296                 return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
297         case IGMPV3_BLOCK_OLD_SOURCES:
298                 if (pmc->sfmode == MCAST_INCLUDE)
299                         return gdeleted || (psf->sf_crcount && sdeleted);
300                 return psf->sf_crcount && !gdeleted && !sdeleted;
301         }
302         return 0;
303 }
304 
305 static int
306 igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
307 {
308         struct ip_sf_list *psf;
309         int scount = 0;
310 
311         for (psf = pmc->sources; psf; psf = psf->sf_next) {
312                 if (!is_in(pmc, psf, type, gdeleted, sdeleted))
313                         continue;
314                 scount++;
315         }
316         return scount;
317 }
318 
319 static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
320 {
321         struct sk_buff *skb;
322         struct rtable *rt;
323         struct iphdr *pip;
324         struct igmpv3_report *pig;
325         struct net *net = dev_net(dev);
326         struct flowi4 fl4;
327         int hlen = LL_RESERVED_SPACE(dev);
328         int tlen = dev->needed_tailroom;
329         unsigned int size = mtu;
330 
331         while (1) {
332                 skb = alloc_skb(size + hlen + tlen,
333                                 GFP_ATOMIC | __GFP_NOWARN);
334                 if (skb)
335                         break;
336                 size >>= 1;
337                 if (size < 256)
338                         return NULL;
339         }
340         skb->priority = TC_PRIO_CONTROL;
341 
342         rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
343                                    0, 0,
344                                    IPPROTO_IGMP, 0, dev->ifindex);
345         if (IS_ERR(rt)) {
346                 kfree_skb(skb);
347                 return NULL;
348         }
349 
350         skb_dst_set(skb, &rt->dst);
351         skb->dev = dev;
352 
353         skb_reserve(skb, hlen);
354         skb_tailroom_reserve(skb, mtu, tlen);
355 
356         skb_reset_network_header(skb);
357         pip = ip_hdr(skb);
358         skb_put(skb, sizeof(struct iphdr) + 4);
359 
360         pip->version  = 4;
361         pip->ihl      = (sizeof(struct iphdr)+4)>>2;
362         pip->tos      = 0xc0;
363         pip->frag_off = htons(IP_DF);
364         pip->ttl      = 1;
365         pip->daddr    = fl4.daddr;
366         pip->saddr    = fl4.saddr;
367         pip->protocol = IPPROTO_IGMP;
368         pip->tot_len  = 0;      /* filled in later */
369         ip_select_ident(net, skb, NULL);
370         ((u8 *)&pip[1])[0] = IPOPT_RA;
371         ((u8 *)&pip[1])[1] = 4;
372         ((u8 *)&pip[1])[2] = 0;
373         ((u8 *)&pip[1])[3] = 0;
374 
375         skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
376         skb_put(skb, sizeof(*pig));
377         pig = igmpv3_report_hdr(skb);
378         pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
379         pig->resv1 = 0;
380         pig->csum = 0;
381         pig->resv2 = 0;
382         pig->ngrec = 0;
383         return skb;
384 }
385 
386 static int igmpv3_sendpack(struct sk_buff *skb)
387 {
388         struct igmphdr *pig = igmp_hdr(skb);
389         const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
390 
391         pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
392 
393         return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
394 }
395 
396 static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
397 {
398         return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
399 }
400 
401 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
402         int type, struct igmpv3_grec **ppgr)
403 {
404         struct net_device *dev = pmc->interface->dev;
405         struct igmpv3_report *pih;
406         struct igmpv3_grec *pgr;
407 
408         if (!skb)
409                 skb = igmpv3_newpack(dev, dev->mtu);
410         if (!skb)
411                 return NULL;
412         pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
413         pgr->grec_type = type;
414         pgr->grec_auxwords = 0;
415         pgr->grec_nsrcs = 0;
416         pgr->grec_mca = pmc->multiaddr;
417         pih = igmpv3_report_hdr(skb);
418         pih->ngrec = htons(ntohs(pih->ngrec)+1);
419         *ppgr = pgr;
420         return skb;
421 }
422 
423 #define AVAILABLE(skb)  ((skb) ? skb_availroom(skb) : 0)
424 
425 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
426         int type, int gdeleted, int sdeleted)
427 {
428         struct net_device *dev = pmc->interface->dev;
429         struct net *net = dev_net(dev);
430         struct igmpv3_report *pih;
431         struct igmpv3_grec *pgr = NULL;
432         struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
433         int scount, stotal, first, isquery, truncate;
434 
435         if (pmc->multiaddr == IGMP_ALL_HOSTS)
436                 return skb;
437         if (ipv4_is_local_multicast(pmc->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
438                 return skb;
439 
440         isquery = type == IGMPV3_MODE_IS_INCLUDE ||
441                   type == IGMPV3_MODE_IS_EXCLUDE;
442         truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
443                     type == IGMPV3_CHANGE_TO_EXCLUDE;
444 
445         stotal = scount = 0;
446 
447         psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
448 
449         if (!*psf_list)
450                 goto empty_source;
451 
452         pih = skb ? igmpv3_report_hdr(skb) : NULL;
453 
454         /* EX and TO_EX get a fresh packet, if needed */
455         if (truncate) {
456                 if (pih && pih->ngrec &&
457                     AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
458                         if (skb)
459                                 igmpv3_sendpack(skb);
460                         skb = igmpv3_newpack(dev, dev->mtu);
461                 }
462         }
463         first = 1;
464         psf_prev = NULL;
465         for (psf = *psf_list; psf; psf = psf_next) {
466                 __be32 *psrc;
467 
468                 psf_next = psf->sf_next;
469 
470                 if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
471                         psf_prev = psf;
472                         continue;
473                 }
474 
475                 /* clear marks on query responses */
476                 if (isquery)
477                         psf->sf_gsresp = 0;
478 
479                 if (AVAILABLE(skb) < sizeof(__be32) +
480                     first*sizeof(struct igmpv3_grec)) {
481                         if (truncate && !first)
482                                 break;   /* truncate these */
483                         if (pgr)
484                                 pgr->grec_nsrcs = htons(scount);
485                         if (skb)
486                                 igmpv3_sendpack(skb);
487                         skb = igmpv3_newpack(dev, dev->mtu);
488                         first = 1;
489                         scount = 0;
490                 }
491                 if (first) {
492                         skb = add_grhead(skb, pmc, type, &pgr);
493                         first = 0;
494                 }
495                 if (!skb)
496                         return NULL;
497                 psrc = (__be32 *)skb_put(skb, sizeof(__be32));
498                 *psrc = psf->sf_inaddr;
499                 scount++; stotal++;
500                 if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
501                      type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
502                         psf->sf_crcount--;
503                         if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
504                                 if (psf_prev)
505                                         psf_prev->sf_next = psf->sf_next;
506                                 else
507                                         *psf_list = psf->sf_next;
508                                 kfree(psf);
509                                 continue;
510                         }
511                 }
512                 psf_prev = psf;
513         }
514 
515 empty_source:
516         if (!stotal) {
517                 if (type == IGMPV3_ALLOW_NEW_SOURCES ||
518                     type == IGMPV3_BLOCK_OLD_SOURCES)
519                         return skb;
520                 if (pmc->crcount || isquery) {
521                         /* make sure we have room for group header */
522                         if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
523                                 igmpv3_sendpack(skb);
524                                 skb = NULL; /* add_grhead will get a new one */
525                         }
526                         skb = add_grhead(skb, pmc, type, &pgr);
527                 }
528         }
529         if (pgr)
530                 pgr->grec_nsrcs = htons(scount);
531 
532         if (isquery)
533                 pmc->gsquery = 0;       /* clear query state on report */
534         return skb;
535 }
536 
537 static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
538 {
539         struct sk_buff *skb = NULL;
540         struct net *net = dev_net(in_dev->dev);
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                         if (ipv4_is_local_multicast(pmc->multiaddr) &&
549                              !net->ipv4.sysctl_igmp_llm_reports)
550                                 continue;
551                         spin_lock_bh(&pmc->lock);
552                         if (pmc->sfcount[MCAST_EXCLUDE])
553                                 type = IGMPV3_MODE_IS_EXCLUDE;
554                         else
555                                 type = IGMPV3_MODE_IS_INCLUDE;
556                         skb = add_grec(skb, pmc, type, 0, 0);
557                         spin_unlock_bh(&pmc->lock);
558                 }
559                 rcu_read_unlock();
560         } else {
561                 spin_lock_bh(&pmc->lock);
562                 if (pmc->sfcount[MCAST_EXCLUDE])
563                         type = IGMPV3_MODE_IS_EXCLUDE;
564                 else
565                         type = IGMPV3_MODE_IS_INCLUDE;
566                 skb = add_grec(skb, pmc, type, 0, 0);
567                 spin_unlock_bh(&pmc->lock);
568         }
569         if (!skb)
570                 return 0;
571         return igmpv3_sendpack(skb);
572 }
573 
574 /*
575  * remove zero-count source records from a source filter list
576  */
577 static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
578 {
579         struct ip_sf_list *psf_prev, *psf_next, *psf;
580 
581         psf_prev = NULL;
582         for (psf = *ppsf; psf; psf = psf_next) {
583                 psf_next = psf->sf_next;
584                 if (psf->sf_crcount == 0) {
585                         if (psf_prev)
586                                 psf_prev->sf_next = psf->sf_next;
587                         else
588                                 *ppsf = psf->sf_next;
589                         kfree(psf);
590                 } else
591                         psf_prev = psf;
592         }
593 }
594 
595 static void igmpv3_send_cr(struct in_device *in_dev)
596 {
597         struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
598         struct sk_buff *skb = NULL;
599         int type, dtype;
600 
601         rcu_read_lock();
602         spin_lock_bh(&in_dev->mc_tomb_lock);
603 
604         /* deleted MCA's */
605         pmc_prev = NULL;
606         for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
607                 pmc_next = pmc->next;
608                 if (pmc->sfmode == MCAST_INCLUDE) {
609                         type = IGMPV3_BLOCK_OLD_SOURCES;
610                         dtype = IGMPV3_BLOCK_OLD_SOURCES;
611                         skb = add_grec(skb, pmc, type, 1, 0);
612                         skb = add_grec(skb, pmc, dtype, 1, 1);
613                 }
614                 if (pmc->crcount) {
615                         if (pmc->sfmode == MCAST_EXCLUDE) {
616                                 type = IGMPV3_CHANGE_TO_INCLUDE;
617                                 skb = add_grec(skb, pmc, type, 1, 0);
618                         }
619                         pmc->crcount--;
620                         if (pmc->crcount == 0) {
621                                 igmpv3_clear_zeros(&pmc->tomb);
622                                 igmpv3_clear_zeros(&pmc->sources);
623                         }
624                 }
625                 if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
626                         if (pmc_prev)
627                                 pmc_prev->next = pmc_next;
628                         else
629                                 in_dev->mc_tomb = pmc_next;
630                         in_dev_put(pmc->interface);
631                         kfree(pmc);
632                 } else
633                         pmc_prev = pmc;
634         }
635         spin_unlock_bh(&in_dev->mc_tomb_lock);
636 
637         /* change recs */
638         for_each_pmc_rcu(in_dev, pmc) {
639                 spin_lock_bh(&pmc->lock);
640                 if (pmc->sfcount[MCAST_EXCLUDE]) {
641                         type = IGMPV3_BLOCK_OLD_SOURCES;
642                         dtype = IGMPV3_ALLOW_NEW_SOURCES;
643                 } else {
644                         type = IGMPV3_ALLOW_NEW_SOURCES;
645                         dtype = IGMPV3_BLOCK_OLD_SOURCES;
646                 }
647                 skb = add_grec(skb, pmc, type, 0, 0);
648                 skb = add_grec(skb, pmc, dtype, 0, 1);  /* deleted sources */
649 
650                 /* filter mode changes */
651                 if (pmc->crcount) {
652                         if (pmc->sfmode == MCAST_EXCLUDE)
653                                 type = IGMPV3_CHANGE_TO_EXCLUDE;
654                         else
655                                 type = IGMPV3_CHANGE_TO_INCLUDE;
656                         skb = add_grec(skb, pmc, type, 0, 0);
657                         pmc->crcount--;
658                 }
659                 spin_unlock_bh(&pmc->lock);
660         }
661         rcu_read_unlock();
662 
663         if (!skb)
664                 return;
665         (void) igmpv3_sendpack(skb);
666 }
667 
668 static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
669         int type)
670 {
671         struct sk_buff *skb;
672         struct iphdr *iph;
673         struct igmphdr *ih;
674         struct rtable *rt;
675         struct net_device *dev = in_dev->dev;
676         struct net *net = dev_net(dev);
677         __be32  group = pmc ? pmc->multiaddr : 0;
678         struct flowi4 fl4;
679         __be32  dst;
680         int hlen, tlen;
681 
682         if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
683                 return igmpv3_send_report(in_dev, pmc);
684 
685         if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
686                 return 0;
687 
688         if (type == IGMP_HOST_LEAVE_MESSAGE)
689                 dst = IGMP_ALL_ROUTER;
690         else
691                 dst = group;
692 
693         rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
694                                    0, 0,
695                                    IPPROTO_IGMP, 0, dev->ifindex);
696         if (IS_ERR(rt))
697                 return -1;
698 
699         hlen = LL_RESERVED_SPACE(dev);
700         tlen = dev->needed_tailroom;
701         skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
702         if (!skb) {
703                 ip_rt_put(rt);
704                 return -1;
705         }
706         skb->priority = TC_PRIO_CONTROL;
707 
708         skb_dst_set(skb, &rt->dst);
709 
710         skb_reserve(skb, hlen);
711 
712         skb_reset_network_header(skb);
713         iph = ip_hdr(skb);
714         skb_put(skb, sizeof(struct iphdr) + 4);
715 
716         iph->version  = 4;
717         iph->ihl      = (sizeof(struct iphdr)+4)>>2;
718         iph->tos      = 0xc0;
719         iph->frag_off = htons(IP_DF);
720         iph->ttl      = 1;
721         iph->daddr    = dst;
722         iph->saddr    = fl4.saddr;
723         iph->protocol = IPPROTO_IGMP;
724         ip_select_ident(net, skb, NULL);
725         ((u8 *)&iph[1])[0] = IPOPT_RA;
726         ((u8 *)&iph[1])[1] = 4;
727         ((u8 *)&iph[1])[2] = 0;
728         ((u8 *)&iph[1])[3] = 0;
729 
730         ih = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
731         ih->type = type;
732         ih->code = 0;
733         ih->csum = 0;
734         ih->group = group;
735         ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
736 
737         return ip_local_out(net, skb->sk, skb);
738 }
739 
740 static void igmp_gq_timer_expire(unsigned long data)
741 {
742         struct in_device *in_dev = (struct in_device *)data;
743 
744         in_dev->mr_gq_running = 0;
745         igmpv3_send_report(in_dev, NULL);
746         in_dev_put(in_dev);
747 }
748 
749 static void igmp_ifc_timer_expire(unsigned long data)
750 {
751         struct in_device *in_dev = (struct in_device *)data;
752 
753         igmpv3_send_cr(in_dev);
754         if (in_dev->mr_ifc_count) {
755                 in_dev->mr_ifc_count--;
756                 igmp_ifc_start_timer(in_dev,
757                                      unsolicited_report_interval(in_dev));
758         }
759         in_dev_put(in_dev);
760 }
761 
762 static void igmp_ifc_event(struct in_device *in_dev)
763 {
764         struct net *net = dev_net(in_dev->dev);
765         if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
766                 return;
767         in_dev->mr_ifc_count = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
768         igmp_ifc_start_timer(in_dev, 1);
769 }
770 
771 
772 static void igmp_timer_expire(unsigned long data)
773 {
774         struct ip_mc_list *im = (struct ip_mc_list *)data;
775         struct in_device *in_dev = im->interface;
776 
777         spin_lock(&im->lock);
778         im->tm_running = 0;
779 
780         if (im->unsolicit_count) {
781                 im->unsolicit_count--;
782                 igmp_start_timer(im, unsolicited_report_interval(in_dev));
783         }
784         im->reporter = 1;
785         spin_unlock(&im->lock);
786 
787         if (IGMP_V1_SEEN(in_dev))
788                 igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
789         else if (IGMP_V2_SEEN(in_dev))
790                 igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
791         else
792                 igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
793 
794         ip_ma_put(im);
795 }
796 
797 /* mark EXCLUDE-mode sources */
798 static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
799 {
800         struct ip_sf_list *psf;
801         int i, scount;
802 
803         scount = 0;
804         for (psf = pmc->sources; psf; psf = psf->sf_next) {
805                 if (scount == nsrcs)
806                         break;
807                 for (i = 0; i < nsrcs; i++) {
808                         /* skip inactive filters */
809                         if (psf->sf_count[MCAST_INCLUDE] ||
810                             pmc->sfcount[MCAST_EXCLUDE] !=
811                             psf->sf_count[MCAST_EXCLUDE])
812                                 break;
813                         if (srcs[i] == psf->sf_inaddr) {
814                                 scount++;
815                                 break;
816                         }
817                 }
818         }
819         pmc->gsquery = 0;
820         if (scount == nsrcs)    /* all sources excluded */
821                 return 0;
822         return 1;
823 }
824 
825 static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
826 {
827         struct ip_sf_list *psf;
828         int i, scount;
829 
830         if (pmc->sfmode == MCAST_EXCLUDE)
831                 return igmp_xmarksources(pmc, nsrcs, srcs);
832 
833         /* mark INCLUDE-mode sources */
834         scount = 0;
835         for (psf = pmc->sources; psf; psf = psf->sf_next) {
836                 if (scount == nsrcs)
837                         break;
838                 for (i = 0; i < nsrcs; i++)
839                         if (srcs[i] == psf->sf_inaddr) {
840                                 psf->sf_gsresp = 1;
841                                 scount++;
842                                 break;
843                         }
844         }
845         if (!scount) {
846                 pmc->gsquery = 0;
847                 return 0;
848         }
849         pmc->gsquery = 1;
850         return 1;
851 }
852 
853 /* return true if packet was dropped */
854 static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
855 {
856         struct ip_mc_list *im;
857         struct net *net = dev_net(in_dev->dev);
858 
859         /* Timers are only set for non-local groups */
860 
861         if (group == IGMP_ALL_HOSTS)
862                 return false;
863         if (ipv4_is_local_multicast(group) && !net->ipv4.sysctl_igmp_llm_reports)
864                 return false;
865 
866         rcu_read_lock();
867         for_each_pmc_rcu(in_dev, im) {
868                 if (im->multiaddr == group) {
869                         igmp_stop_timer(im);
870                         break;
871                 }
872         }
873         rcu_read_unlock();
874         return false;
875 }
876 
877 /* return true if packet was dropped */
878 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
879         int len)
880 {
881         struct igmphdr          *ih = igmp_hdr(skb);
882         struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
883         struct ip_mc_list       *im;
884         __be32                  group = ih->group;
885         int                     max_delay;
886         int                     mark = 0;
887         struct net              *net = dev_net(in_dev->dev);
888 
889 
890         if (len == 8) {
891                 if (ih->code == 0) {
892                         /* Alas, old v1 router presents here. */
893 
894                         max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
895                         in_dev->mr_v1_seen = jiffies +
896                                 IGMP_V1_ROUTER_PRESENT_TIMEOUT;
897                         group = 0;
898                 } else {
899                         /* v2 router present */
900                         max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
901                         in_dev->mr_v2_seen = jiffies +
902                                 IGMP_V2_ROUTER_PRESENT_TIMEOUT;
903                 }
904                 /* cancel the interface change timer */
905                 in_dev->mr_ifc_count = 0;
906                 if (del_timer(&in_dev->mr_ifc_timer))
907                         __in_dev_put(in_dev);
908                 /* clear deleted report items */
909                 igmpv3_clear_delrec(in_dev);
910         } else if (len < 12) {
911                 return true;    /* ignore bogus packet; freed by caller */
912         } else if (IGMP_V1_SEEN(in_dev)) {
913                 /* This is a v3 query with v1 queriers present */
914                 max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
915                 group = 0;
916         } else if (IGMP_V2_SEEN(in_dev)) {
917                 /* this is a v3 query with v2 queriers present;
918                  * Interpretation of the max_delay code is problematic here.
919                  * A real v2 host would use ih_code directly, while v3 has a
920                  * different encoding. We use the v3 encoding as more likely
921                  * to be intended in a v3 query.
922                  */
923                 max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
924                 if (!max_delay)
925                         max_delay = 1;  /* can't mod w/ 0 */
926         } else { /* v3 */
927                 if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
928                         return true;
929 
930                 ih3 = igmpv3_query_hdr(skb);
931                 if (ih3->nsrcs) {
932                         if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
933                                            + ntohs(ih3->nsrcs)*sizeof(__be32)))
934                                 return true;
935                         ih3 = igmpv3_query_hdr(skb);
936                 }
937 
938                 max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
939                 if (!max_delay)
940                         max_delay = 1;  /* can't mod w/ 0 */
941                 in_dev->mr_maxdelay = max_delay;
942                 if (ih3->qrv)
943                         in_dev->mr_qrv = ih3->qrv;
944                 if (!group) { /* general query */
945                         if (ih3->nsrcs)
946                                 return true;    /* no sources allowed */
947                         igmp_gq_start_timer(in_dev);
948                         return false;
949                 }
950                 /* mark sources to include, if group & source-specific */
951                 mark = ih3->nsrcs != 0;
952         }
953 
954         /*
955          * - Start the timers in all of our membership records
956          *   that the query applies to for the interface on
957          *   which the query arrived excl. those that belong
958          *   to a "local" group (224.0.0.X)
959          * - For timers already running check if they need to
960          *   be reset.
961          * - Use the igmp->igmp_code field as the maximum
962          *   delay possible
963          */
964         rcu_read_lock();
965         for_each_pmc_rcu(in_dev, im) {
966                 int changed;
967 
968                 if (group && group != im->multiaddr)
969                         continue;
970                 if (im->multiaddr == IGMP_ALL_HOSTS)
971                         continue;
972                 if (ipv4_is_local_multicast(im->multiaddr) &&
973                     !net->ipv4.sysctl_igmp_llm_reports)
974                         continue;
975                 spin_lock_bh(&im->lock);
976                 if (im->tm_running)
977                         im->gsquery = im->gsquery && mark;
978                 else
979                         im->gsquery = mark;
980                 changed = !im->gsquery ||
981                         igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
982                 spin_unlock_bh(&im->lock);
983                 if (changed)
984                         igmp_mod_timer(im, max_delay);
985         }
986         rcu_read_unlock();
987         return false;
988 }
989 
990 /* called in rcu_read_lock() section */
991 int igmp_rcv(struct sk_buff *skb)
992 {
993         /* This basically follows the spec line by line -- see RFC1112 */
994         struct igmphdr *ih;
995         struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
996         int len = skb->len;
997         bool dropped = true;
998 
999         if (!in_dev)
1000                 goto drop;
1001 
1002         if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
1003                 goto drop;
1004 
1005         if (skb_checksum_simple_validate(skb))
1006                 goto drop;
1007 
1008         ih = igmp_hdr(skb);
1009         switch (ih->type) {
1010         case IGMP_HOST_MEMBERSHIP_QUERY:
1011                 dropped = igmp_heard_query(in_dev, skb, len);
1012                 break;
1013         case IGMP_HOST_MEMBERSHIP_REPORT:
1014         case IGMPV2_HOST_MEMBERSHIP_REPORT:
1015                 /* Is it our report looped back? */
1016                 if (rt_is_output_route(skb_rtable(skb)))
1017                         break;
1018                 /* don't rely on MC router hearing unicast reports */
1019                 if (skb->pkt_type == PACKET_MULTICAST ||
1020                     skb->pkt_type == PACKET_BROADCAST)
1021                         dropped = igmp_heard_report(in_dev, ih->group);
1022                 break;
1023         case IGMP_PIM:
1024 #ifdef CONFIG_IP_PIMSM_V1
1025                 return pim_rcv_v1(skb);
1026 #endif
1027         case IGMPV3_HOST_MEMBERSHIP_REPORT:
1028         case IGMP_DVMRP:
1029         case IGMP_TRACE:
1030         case IGMP_HOST_LEAVE_MESSAGE:
1031         case IGMP_MTRACE:
1032         case IGMP_MTRACE_RESP:
1033                 break;
1034         default:
1035                 break;
1036         }
1037 
1038 drop:
1039         if (dropped)
1040                 kfree_skb(skb);
1041         else
1042                 consume_skb(skb);
1043         return 0;
1044 }
1045 
1046 #endif
1047 
1048 
1049 /*
1050  *      Add a filter to a device
1051  */
1052 
1053 static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
1054 {
1055         char buf[MAX_ADDR_LEN];
1056         struct net_device *dev = in_dev->dev;
1057 
1058         /* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
1059            We will get multicast token leakage, when IFF_MULTICAST
1060            is changed. This check should be done in ndo_set_rx_mode
1061            routine. Something sort of:
1062            if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
1063            --ANK
1064            */
1065         if (arp_mc_map(addr, buf, dev, 0) == 0)
1066                 dev_mc_add(dev, buf);
1067 }
1068 
1069 /*
1070  *      Remove a filter from a device
1071  */
1072 
1073 static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
1074 {
1075         char buf[MAX_ADDR_LEN];
1076         struct net_device *dev = in_dev->dev;
1077 
1078         if (arp_mc_map(addr, buf, dev, 0) == 0)
1079                 dev_mc_del(dev, buf);
1080 }
1081 
1082 #ifdef CONFIG_IP_MULTICAST
1083 /*
1084  * deleted ip_mc_list manipulation
1085  */
1086 static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im)
1087 {
1088         struct ip_mc_list *pmc;
1089         struct net *net = dev_net(in_dev->dev);
1090 
1091         /* this is an "ip_mc_list" for convenience; only the fields below
1092          * are actually used. In particular, the refcnt and users are not
1093          * used for management of the delete list. Using the same structure
1094          * for deleted items allows change reports to use common code with
1095          * non-deleted or query-response MCA's.
1096          */
1097         pmc = kzalloc(sizeof(*pmc), GFP_KERNEL);
1098         if (!pmc)
1099                 return;
1100         spin_lock_bh(&im->lock);
1101         pmc->interface = im->interface;
1102         in_dev_hold(in_dev);
1103         pmc->multiaddr = im->multiaddr;
1104         pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1105         pmc->sfmode = im->sfmode;
1106         if (pmc->sfmode == MCAST_INCLUDE) {
1107                 struct ip_sf_list *psf;
1108 
1109                 pmc->tomb = im->tomb;
1110                 pmc->sources = im->sources;
1111                 im->tomb = im->sources = NULL;
1112                 for (psf = pmc->sources; psf; psf = psf->sf_next)
1113                         psf->sf_crcount = pmc->crcount;
1114         }
1115         spin_unlock_bh(&im->lock);
1116 
1117         spin_lock_bh(&in_dev->mc_tomb_lock);
1118         pmc->next = in_dev->mc_tomb;
1119         in_dev->mc_tomb = pmc;
1120         spin_unlock_bh(&in_dev->mc_tomb_lock);
1121 }
1122 
1123 static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr)
1124 {
1125         struct ip_mc_list *pmc, *pmc_prev;
1126         struct ip_sf_list *psf, *psf_next;
1127 
1128         spin_lock_bh(&in_dev->mc_tomb_lock);
1129         pmc_prev = NULL;
1130         for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
1131                 if (pmc->multiaddr == multiaddr)
1132                         break;
1133                 pmc_prev = pmc;
1134         }
1135         if (pmc) {
1136                 if (pmc_prev)
1137                         pmc_prev->next = pmc->next;
1138                 else
1139                         in_dev->mc_tomb = pmc->next;
1140         }
1141         spin_unlock_bh(&in_dev->mc_tomb_lock);
1142         if (pmc) {
1143                 for (psf = pmc->tomb; psf; psf = psf_next) {
1144                         psf_next = psf->sf_next;
1145                         kfree(psf);
1146                 }
1147                 in_dev_put(pmc->interface);
1148                 kfree(pmc);
1149         }
1150 }
1151 
1152 static void igmpv3_clear_delrec(struct in_device *in_dev)
1153 {
1154         struct ip_mc_list *pmc, *nextpmc;
1155 
1156         spin_lock_bh(&in_dev->mc_tomb_lock);
1157         pmc = in_dev->mc_tomb;
1158         in_dev->mc_tomb = NULL;
1159         spin_unlock_bh(&in_dev->mc_tomb_lock);
1160 
1161         for (; pmc; pmc = nextpmc) {
1162                 nextpmc = pmc->next;
1163                 ip_mc_clear_src(pmc);
1164                 in_dev_put(pmc->interface);
1165                 kfree(pmc);
1166         }
1167         /* clear dead sources, too */
1168         rcu_read_lock();
1169         for_each_pmc_rcu(in_dev, pmc) {
1170                 struct ip_sf_list *psf, *psf_next;
1171 
1172                 spin_lock_bh(&pmc->lock);
1173                 psf = pmc->tomb;
1174                 pmc->tomb = NULL;
1175                 spin_unlock_bh(&pmc->lock);
1176                 for (; psf; psf = psf_next) {
1177                         psf_next = psf->sf_next;
1178                         kfree(psf);
1179                 }
1180         }
1181         rcu_read_unlock();
1182 }
1183 #endif
1184 
1185 static void igmp_group_dropped(struct ip_mc_list *im)
1186 {
1187         struct in_device *in_dev = im->interface;
1188 #ifdef CONFIG_IP_MULTICAST
1189         struct net *net = dev_net(in_dev->dev);
1190         int reporter;
1191 #endif
1192 
1193         if (im->loaded) {
1194                 im->loaded = 0;
1195                 ip_mc_filter_del(in_dev, im->multiaddr);
1196         }
1197 
1198 #ifdef CONFIG_IP_MULTICAST
1199         if (im->multiaddr == IGMP_ALL_HOSTS)
1200                 return;
1201         if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1202                 return;
1203 
1204         reporter = im->reporter;
1205         igmp_stop_timer(im);
1206 
1207         if (!in_dev->dead) {
1208                 if (IGMP_V1_SEEN(in_dev))
1209                         return;
1210                 if (IGMP_V2_SEEN(in_dev)) {
1211                         if (reporter)
1212                                 igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
1213                         return;
1214                 }
1215                 /* IGMPv3 */
1216                 igmpv3_add_delrec(in_dev, im);
1217 
1218                 igmp_ifc_event(in_dev);
1219         }
1220 #endif
1221 }
1222 
1223 static void igmp_group_added(struct ip_mc_list *im)
1224 {
1225         struct in_device *in_dev = im->interface;
1226 #ifdef CONFIG_IP_MULTICAST
1227         struct net *net = dev_net(in_dev->dev);
1228 #endif
1229 
1230         if (im->loaded == 0) {
1231                 im->loaded = 1;
1232                 ip_mc_filter_add(in_dev, im->multiaddr);
1233         }
1234 
1235 #ifdef CONFIG_IP_MULTICAST
1236         if (im->multiaddr == IGMP_ALL_HOSTS)
1237                 return;
1238         if (ipv4_is_local_multicast(im->multiaddr) && !net->ipv4.sysctl_igmp_llm_reports)
1239                 return;
1240 
1241         if (in_dev->dead)
1242                 return;
1243         if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
1244                 spin_lock_bh(&im->lock);
1245                 igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
1246                 spin_unlock_bh(&im->lock);
1247                 return;
1248         }
1249         /* else, v3 */
1250 
1251         im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1252         igmp_ifc_event(in_dev);
1253 #endif
1254 }
1255 
1256 
1257 /*
1258  *      Multicast list managers
1259  */
1260 
1261 static u32 ip_mc_hash(const struct ip_mc_list *im)
1262 {
1263         return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
1264 }
1265 
1266 static void ip_mc_hash_add(struct in_device *in_dev,
1267                            struct ip_mc_list *im)
1268 {
1269         struct ip_mc_list __rcu **mc_hash;
1270         u32 hash;
1271 
1272         mc_hash = rtnl_dereference(in_dev->mc_hash);
1273         if (mc_hash) {
1274                 hash = ip_mc_hash(im);
1275                 im->next_hash = mc_hash[hash];
1276                 rcu_assign_pointer(mc_hash[hash], im);
1277                 return;
1278         }
1279 
1280         /* do not use a hash table for small number of items */
1281         if (in_dev->mc_count < 4)
1282                 return;
1283 
1284         mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
1285                           GFP_KERNEL);
1286         if (!mc_hash)
1287                 return;
1288 
1289         for_each_pmc_rtnl(in_dev, im) {
1290                 hash = ip_mc_hash(im);
1291                 im->next_hash = mc_hash[hash];
1292                 RCU_INIT_POINTER(mc_hash[hash], im);
1293         }
1294 
1295         rcu_assign_pointer(in_dev->mc_hash, mc_hash);
1296 }
1297 
1298 static void ip_mc_hash_remove(struct in_device *in_dev,
1299                               struct ip_mc_list *im)
1300 {
1301         struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
1302         struct ip_mc_list *aux;
1303 
1304         if (!mc_hash)
1305                 return;
1306         mc_hash += ip_mc_hash(im);
1307         while ((aux = rtnl_dereference(*mc_hash)) != im)
1308                 mc_hash = &aux->next_hash;
1309         *mc_hash = im->next_hash;
1310 }
1311 
1312 
1313 /*
1314  *      A socket has joined a multicast group on device dev.
1315  */
1316 
1317 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
1318 {
1319         struct ip_mc_list *im;
1320 #ifdef CONFIG_IP_MULTICAST
1321         struct net *net = dev_net(in_dev->dev);
1322 #endif
1323 
1324         ASSERT_RTNL();
1325 
1326         for_each_pmc_rtnl(in_dev, im) {
1327                 if (im->multiaddr == addr) {
1328                         im->users++;
1329                         ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, NULL, 0);
1330                         goto out;
1331                 }
1332         }
1333 
1334         im = kzalloc(sizeof(*im), GFP_KERNEL);
1335         if (!im)
1336                 goto out;
1337 
1338         im->users = 1;
1339         im->interface = in_dev;
1340         in_dev_hold(in_dev);
1341         im->multiaddr = addr;
1342         /* initial mode is (EX, empty) */
1343         im->sfmode = MCAST_EXCLUDE;
1344         im->sfcount[MCAST_EXCLUDE] = 1;
1345         atomic_set(&im->refcnt, 1);
1346         spin_lock_init(&im->lock);
1347 #ifdef CONFIG_IP_MULTICAST
1348         setup_timer(&im->timer, igmp_timer_expire, (unsigned long)im);
1349         im->unsolicit_count = net->ipv4.sysctl_igmp_qrv;
1350 #endif
1351 
1352         im->next_rcu = in_dev->mc_list;
1353         in_dev->mc_count++;
1354         rcu_assign_pointer(in_dev->mc_list, im);
1355 
1356         ip_mc_hash_add(in_dev, im);
1357 
1358 #ifdef CONFIG_IP_MULTICAST
1359         igmpv3_del_delrec(in_dev, im->multiaddr);
1360 #endif
1361         igmp_group_added(im);
1362         if (!in_dev->dead)
1363                 ip_rt_multicast_event(in_dev);
1364 out:
1365         return;
1366 }
1367 EXPORT_SYMBOL(ip_mc_inc_group);
1368 
1369 static int ip_mc_check_iphdr(struct sk_buff *skb)
1370 {
1371         const struct iphdr *iph;
1372         unsigned int len;
1373         unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
1374 
1375         if (!pskb_may_pull(skb, offset))
1376                 return -EINVAL;
1377 
1378         iph = ip_hdr(skb);
1379 
1380         if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
1381                 return -EINVAL;
1382 
1383         offset += ip_hdrlen(skb) - sizeof(*iph);
1384 
1385         if (!pskb_may_pull(skb, offset))
1386                 return -EINVAL;
1387 
1388         iph = ip_hdr(skb);
1389 
1390         if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1391                 return -EINVAL;
1392 
1393         len = skb_network_offset(skb) + ntohs(iph->tot_len);
1394         if (skb->len < len || len < offset)
1395                 return -EINVAL;
1396 
1397         skb_set_transport_header(skb, offset);
1398 
1399         return 0;
1400 }
1401 
1402 static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
1403 {
1404         unsigned int len = skb_transport_offset(skb);
1405 
1406         len += sizeof(struct igmpv3_report);
1407 
1408         return pskb_may_pull(skb, len) ? 0 : -EINVAL;
1409 }
1410 
1411 static int ip_mc_check_igmp_query(struct sk_buff *skb)
1412 {
1413         unsigned int len = skb_transport_offset(skb);
1414 
1415         len += sizeof(struct igmphdr);
1416         if (skb->len < len)
1417                 return -EINVAL;
1418 
1419         /* IGMPv{1,2}? */
1420         if (skb->len != len) {
1421                 /* or IGMPv3? */
1422                 len += sizeof(struct igmpv3_query) - sizeof(struct igmphdr);
1423                 if (skb->len < len || !pskb_may_pull(skb, len))
1424                         return -EINVAL;
1425         }
1426 
1427         /* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
1428          * all-systems destination addresses (224.0.0.1) for general queries
1429          */
1430         if (!igmp_hdr(skb)->group &&
1431             ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
1432                 return -EINVAL;
1433 
1434         return 0;
1435 }
1436 
1437 static int ip_mc_check_igmp_msg(struct sk_buff *skb)
1438 {
1439         switch (igmp_hdr(skb)->type) {
1440         case IGMP_HOST_LEAVE_MESSAGE:
1441         case IGMP_HOST_MEMBERSHIP_REPORT:
1442         case IGMPV2_HOST_MEMBERSHIP_REPORT:
1443                 /* fall through */
1444                 return 0;
1445         case IGMPV3_HOST_MEMBERSHIP_REPORT:
1446                 return ip_mc_check_igmp_reportv3(skb);
1447         case IGMP_HOST_MEMBERSHIP_QUERY:
1448                 return ip_mc_check_igmp_query(skb);
1449         default:
1450                 return -ENOMSG;
1451         }
1452 }
1453 
1454 static inline __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
1455 {
1456         return skb_checksum_simple_validate(skb);
1457 }
1458 
1459 static int __ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
1460 
1461 {
1462         struct sk_buff *skb_chk;
1463         unsigned int transport_len;
1464         unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
1465         int ret = -EINVAL;
1466 
1467         transport_len = ntohs(ip_hdr(skb)->tot_len) - ip_hdrlen(skb);
1468 
1469         skb_chk = skb_checksum_trimmed(skb, transport_len,
1470                                        ip_mc_validate_checksum);
1471         if (!skb_chk)
1472                 goto err;
1473 
1474         if (!pskb_may_pull(skb_chk, len))
1475                 goto err;
1476 
1477         ret = ip_mc_check_igmp_msg(skb_chk);
1478         if (ret)
1479                 goto err;
1480 
1481         if (skb_trimmed)
1482                 *skb_trimmed = skb_chk;
1483         /* free now unneeded clone */
1484         else if (skb_chk != skb)
1485                 kfree_skb(skb_chk);
1486 
1487         ret = 0;
1488 
1489 err:
1490         if (ret && skb_chk && skb_chk != skb)
1491                 kfree_skb(skb_chk);
1492 
1493         return ret;
1494 }
1495 
1496 /**
1497  * ip_mc_check_igmp - checks whether this is a sane IGMP packet
1498  * @skb: the skb to validate
1499  * @skb_trimmed: to store an skb pointer trimmed to IPv4 packet tail (optional)
1500  *
1501  * Checks whether an IPv4 packet is a valid IGMP packet. If so sets
1502  * skb transport header accordingly and returns zero.
1503  *
1504  * -EINVAL: A broken packet was detected, i.e. it violates some internet
1505  *  standard
1506  * -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
1507  * -ENOMEM: A memory allocation failure happened.
1508  *
1509  * Optionally, an skb pointer might be provided via skb_trimmed (or set it
1510  * to NULL): After parsing an IGMP packet successfully it will point to
1511  * an skb which has its tail aligned to the IP packet end. This might
1512  * either be the originally provided skb or a trimmed, cloned version if
1513  * the skb frame had data beyond the IP packet. A cloned skb allows us
1514  * to leave the original skb and its full frame unchanged (which might be
1515  * desirable for layer 2 frame jugglers).
1516  *
1517  * Caller needs to set the skb network header and free any returned skb if it
1518  * differs from the provided skb.
1519  */
1520 int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed)
1521 {
1522         int ret = ip_mc_check_iphdr(skb);
1523 
1524         if (ret < 0)
1525                 return ret;
1526 
1527         if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
1528                 return -ENOMSG;
1529 
1530         return __ip_mc_check_igmp(skb, skb_trimmed);
1531 }
1532 EXPORT_SYMBOL(ip_mc_check_igmp);
1533 
1534 /*
1535  *      Resend IGMP JOIN report; used by netdev notifier.
1536  */
1537 static void ip_mc_rejoin_groups(struct in_device *in_dev)
1538 {
1539 #ifdef CONFIG_IP_MULTICAST
1540         struct ip_mc_list *im;
1541         int type;
1542         struct net *net = dev_net(in_dev->dev);
1543 
1544         ASSERT_RTNL();
1545 
1546         for_each_pmc_rtnl(in_dev, im) {
1547                 if (im->multiaddr == IGMP_ALL_HOSTS)
1548                         continue;
1549                 if (ipv4_is_local_multicast(im->multiaddr) &&
1550                     !net->ipv4.sysctl_igmp_llm_reports)
1551                         continue;
1552 
1553                 /* a failover is happening and switches
1554                  * must be notified immediately
1555                  */
1556                 if (IGMP_V1_SEEN(in_dev))
1557                         type = IGMP_HOST_MEMBERSHIP_REPORT;
1558                 else if (IGMP_V2_SEEN(in_dev))
1559                         type = IGMPV2_HOST_MEMBERSHIP_REPORT;
1560                 else
1561                         type = IGMPV3_HOST_MEMBERSHIP_REPORT;
1562                 igmp_send_report(in_dev, im, type);
1563         }
1564 #endif
1565 }
1566 
1567 /*
1568  *      A socket has left a multicast group on device dev
1569  */
1570 
1571 void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
1572 {
1573         struct ip_mc_list *i;
1574         struct ip_mc_list __rcu **ip;
1575 
1576         ASSERT_RTNL();
1577 
1578         for (ip = &in_dev->mc_list;
1579              (i = rtnl_dereference(*ip)) != NULL;
1580              ip = &i->next_rcu) {
1581                 if (i->multiaddr == addr) {
1582                         if (--i->users == 0) {
1583                                 ip_mc_hash_remove(in_dev, i);
1584                                 *ip = i->next_rcu;
1585                                 in_dev->mc_count--;
1586                                 igmp_group_dropped(i);
1587                                 ip_mc_clear_src(i);
1588 
1589                                 if (!in_dev->dead)
1590                                         ip_rt_multicast_event(in_dev);
1591 
1592                                 ip_ma_put(i);
1593                                 return;
1594                         }
1595                         break;
1596                 }
1597         }
1598 }
1599 EXPORT_SYMBOL(ip_mc_dec_group);
1600 
1601 /* Device changing type */
1602 
1603 void ip_mc_unmap(struct in_device *in_dev)
1604 {
1605         struct ip_mc_list *pmc;
1606 
1607         ASSERT_RTNL();
1608 
1609         for_each_pmc_rtnl(in_dev, pmc)
1610                 igmp_group_dropped(pmc);
1611 }
1612 
1613 void ip_mc_remap(struct in_device *in_dev)
1614 {
1615         struct ip_mc_list *pmc;
1616 
1617         ASSERT_RTNL();
1618 
1619         for_each_pmc_rtnl(in_dev, pmc)
1620                 igmp_group_added(pmc);
1621 }
1622 
1623 /* Device going down */
1624 
1625 void ip_mc_down(struct in_device *in_dev)
1626 {
1627         struct ip_mc_list *pmc;
1628 
1629         ASSERT_RTNL();
1630 
1631         for_each_pmc_rtnl(in_dev, pmc)
1632                 igmp_group_dropped(pmc);
1633 
1634 #ifdef CONFIG_IP_MULTICAST
1635         in_dev->mr_ifc_count = 0;
1636         if (del_timer(&in_dev->mr_ifc_timer))
1637                 __in_dev_put(in_dev);
1638         in_dev->mr_gq_running = 0;
1639         if (del_timer(&in_dev->mr_gq_timer))
1640                 __in_dev_put(in_dev);
1641         igmpv3_clear_delrec(in_dev);
1642 #endif
1643 
1644         ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
1645 }
1646 
1647 void ip_mc_init_dev(struct in_device *in_dev)
1648 {
1649 #ifdef CONFIG_IP_MULTICAST
1650         struct net *net = dev_net(in_dev->dev);
1651 #endif
1652         ASSERT_RTNL();
1653 
1654 #ifdef CONFIG_IP_MULTICAST
1655         setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
1656                         (unsigned long)in_dev);
1657         setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
1658                         (unsigned long)in_dev);
1659         in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
1660 #endif
1661 
1662         spin_lock_init(&in_dev->mc_tomb_lock);
1663 }
1664 
1665 /* Device going up */
1666 
1667 void ip_mc_up(struct in_device *in_dev)
1668 {
1669         struct ip_mc_list *pmc;
1670 #ifdef CONFIG_IP_MULTICAST
1671         struct net *net = dev_net(in_dev->dev);
1672 #endif
1673 
1674         ASSERT_RTNL();
1675 
1676 #ifdef CONFIG_IP_MULTICAST
1677         in_dev->mr_qrv = net->ipv4.sysctl_igmp_qrv;
1678 #endif
1679         ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
1680 
1681         for_each_pmc_rtnl(in_dev, pmc)
1682                 igmp_group_added(pmc);
1683 }
1684 
1685 /*
1686  *      Device is about to be destroyed: clean up.
1687  */
1688 
1689 void ip_mc_destroy_dev(struct in_device *in_dev)
1690 {
1691         struct ip_mc_list *i;
1692 
1693         ASSERT_RTNL();
1694 
1695         /* Deactivate timers */
1696         ip_mc_down(in_dev);
1697 
1698         while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
1699                 in_dev->mc_list = i->next_rcu;
1700                 in_dev->mc_count--;
1701 
1702                 /* We've dropped the groups in ip_mc_down already */
1703                 ip_mc_clear_src(i);
1704                 ip_ma_put(i);
1705         }
1706 }
1707 
1708 /* RTNL is locked */
1709 static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
1710 {
1711         struct net_device *dev = NULL;
1712         struct in_device *idev = NULL;
1713 
1714         if (imr->imr_ifindex) {
1715                 idev = inetdev_by_index(net, imr->imr_ifindex);
1716                 return idev;
1717         }
1718         if (imr->imr_address.s_addr) {
1719                 dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
1720                 if (!dev)
1721                         return NULL;
1722         }
1723 
1724         if (!dev) {
1725                 struct rtable *rt = ip_route_output(net,
1726                                                     imr->imr_multiaddr.s_addr,
1727                                                     0, 0, 0);
1728                 if (!IS_ERR(rt)) {
1729                         dev = rt->dst.dev;
1730                         ip_rt_put(rt);
1731                 }
1732         }
1733         if (dev) {
1734                 imr->imr_ifindex = dev->ifindex;
1735                 idev = __in_dev_get_rtnl(dev);
1736         }
1737         return idev;
1738 }
1739 
1740 /*
1741  *      Join a socket to a group
1742  */
1743 
1744 static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
1745         __be32 *psfsrc)
1746 {
1747         struct ip_sf_list *psf, *psf_prev;
1748         int rv = 0;
1749 
1750         psf_prev = NULL;
1751         for (psf = pmc->sources; psf; psf = psf->sf_next) {
1752                 if (psf->sf_inaddr == *psfsrc)
1753                         break;
1754                 psf_prev = psf;
1755         }
1756         if (!psf || psf->sf_count[sfmode] == 0) {
1757                 /* source filter not found, or count wrong =>  bug */
1758                 return -ESRCH;
1759         }
1760         psf->sf_count[sfmode]--;
1761         if (psf->sf_count[sfmode] == 0) {
1762                 ip_rt_multicast_event(pmc->interface);
1763         }
1764         if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
1765 #ifdef CONFIG_IP_MULTICAST
1766                 struct in_device *in_dev = pmc->interface;
1767                 struct net *net = dev_net(in_dev->dev);
1768 #endif
1769 
1770                 /* no more filters for this source */
1771                 if (psf_prev)
1772                         psf_prev->sf_next = psf->sf_next;
1773                 else
1774                         pmc->sources = psf->sf_next;
1775 #ifdef CONFIG_IP_MULTICAST
1776                 if (psf->sf_oldin &&
1777                     !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
1778                         psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1779                         psf->sf_next = pmc->tomb;
1780                         pmc->tomb = psf;
1781                         rv = 1;
1782                 } else
1783 #endif
1784                         kfree(psf);
1785         }
1786         return rv;
1787 }
1788 
1789 #ifndef CONFIG_IP_MULTICAST
1790 #define igmp_ifc_event(x)       do { } while (0)
1791 #endif
1792 
1793 static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1794                          int sfcount, __be32 *psfsrc, int delta)
1795 {
1796         struct ip_mc_list *pmc;
1797         int     changerec = 0;
1798         int     i, err;
1799 
1800         if (!in_dev)
1801                 return -ENODEV;
1802         rcu_read_lock();
1803         for_each_pmc_rcu(in_dev, pmc) {
1804                 if (*pmca == pmc->multiaddr)
1805                         break;
1806         }
1807         if (!pmc) {
1808                 /* MCA not found?? bug */
1809                 rcu_read_unlock();
1810                 return -ESRCH;
1811         }
1812         spin_lock_bh(&pmc->lock);
1813         rcu_read_unlock();
1814 #ifdef CONFIG_IP_MULTICAST
1815         sf_markstate(pmc);
1816 #endif
1817         if (!delta) {
1818                 err = -EINVAL;
1819                 if (!pmc->sfcount[sfmode])
1820                         goto out_unlock;
1821                 pmc->sfcount[sfmode]--;
1822         }
1823         err = 0;
1824         for (i = 0; i < sfcount; i++) {
1825                 int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
1826 
1827                 changerec |= rv > 0;
1828                 if (!err && rv < 0)
1829                         err = rv;
1830         }
1831         if (pmc->sfmode == MCAST_EXCLUDE &&
1832             pmc->sfcount[MCAST_EXCLUDE] == 0 &&
1833             pmc->sfcount[MCAST_INCLUDE]) {
1834 #ifdef CONFIG_IP_MULTICAST
1835                 struct ip_sf_list *psf;
1836                 struct net *net = dev_net(in_dev->dev);
1837 #endif
1838 
1839                 /* filter mode change */
1840                 pmc->sfmode = MCAST_INCLUDE;
1841 #ifdef CONFIG_IP_MULTICAST
1842                 pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
1843                 in_dev->mr_ifc_count = pmc->crcount;
1844                 for (psf = pmc->sources; psf; psf = psf->sf_next)
1845                         psf->sf_crcount = 0;
1846                 igmp_ifc_event(pmc->interface);
1847         } else if (sf_setstate(pmc) || changerec) {
1848                 igmp_ifc_event(pmc->interface);
1849 #endif
1850         }
1851 out_unlock:
1852         spin_unlock_bh(&pmc->lock);
1853         return err;
1854 }
1855 
1856 /*
1857  * Add multicast single-source filter to the interface list
1858  */
1859 static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
1860         __be32 *psfsrc)
1861 {
1862         struct ip_sf_list *psf, *psf_prev;
1863 
1864         psf_prev = NULL;
1865         for (psf = pmc->sources; psf; psf = psf->sf_next) {
1866                 if (psf->sf_inaddr == *psfsrc)
1867                         break;
1868                 psf_prev = psf;
1869         }
1870         if (!psf) {
1871                 psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
1872                 if (!psf)
1873                         return -ENOBUFS;
1874                 psf->sf_inaddr = *psfsrc;
1875                 if (psf_prev) {
1876                         psf_prev->sf_next = psf;
1877                 } else
1878                         pmc->sources = psf;
1879         }
1880         psf->sf_count[sfmode]++;
1881         if (psf->sf_count[sfmode] == 1) {
1882                 ip_rt_multicast_event(pmc->interface);
1883         }
1884         return 0;
1885 }
1886 
1887 #ifdef CONFIG_IP_MULTICAST
1888 static void sf_markstate(struct ip_mc_list *pmc)
1889 {
1890         struct ip_sf_list *psf;
1891         int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1892 
1893         for (psf = pmc->sources; psf; psf = psf->sf_next)
1894                 if (pmc->sfcount[MCAST_EXCLUDE]) {
1895                         psf->sf_oldin = mca_xcount ==
1896                                 psf->sf_count[MCAST_EXCLUDE] &&
1897                                 !psf->sf_count[MCAST_INCLUDE];
1898                 } else
1899                         psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
1900 }
1901 
1902 static int sf_setstate(struct ip_mc_list *pmc)
1903 {
1904         struct ip_sf_list *psf, *dpsf;
1905         int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
1906         int qrv = pmc->interface->mr_qrv;
1907         int new_in, rv;
1908 
1909         rv = 0;
1910         for (psf = pmc->sources; psf; psf = psf->sf_next) {
1911                 if (pmc->sfcount[MCAST_EXCLUDE]) {
1912                         new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
1913                                 !psf->sf_count[MCAST_INCLUDE];
1914                 } else
1915                         new_in = psf->sf_count[MCAST_INCLUDE] != 0;
1916                 if (new_in) {
1917                         if (!psf->sf_oldin) {
1918                                 struct ip_sf_list *prev = NULL;
1919 
1920                                 for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
1921                                         if (dpsf->sf_inaddr == psf->sf_inaddr)
1922                                                 break;
1923                                         prev = dpsf;
1924                                 }
1925                                 if (dpsf) {
1926                                         if (prev)
1927                                                 prev->sf_next = dpsf->sf_next;
1928                                         else
1929                                                 pmc->tomb = dpsf->sf_next;
1930                                         kfree(dpsf);
1931                                 }
1932                                 psf->sf_crcount = qrv;
1933                                 rv++;
1934                         }
1935                 } else if (psf->sf_oldin) {
1936 
1937                         psf->sf_crcount = 0;
1938                         /*
1939                          * add or update "delete" records if an active filter
1940                          * is now inactive
1941                          */
1942                         for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
1943                                 if (dpsf->sf_inaddr == psf->sf_inaddr)
1944                                         break;
1945                         if (!dpsf) {
1946                                 dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
1947                                 if (!dpsf)
1948                                         continue;
1949                                 *dpsf = *psf;
1950                                 /* pmc->lock held by callers */
1951                                 dpsf->sf_next = pmc->tomb;
1952                                 pmc->tomb = dpsf;
1953                         }
1954                         dpsf->sf_crcount = qrv;
1955                         rv++;
1956                 }
1957         }
1958         return rv;
1959 }
1960 #endif
1961 
1962 /*
1963  * Add multicast source filter list to the interface list
1964  */
1965 static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
1966                          int sfcount, __be32 *psfsrc, int delta)
1967 {
1968         struct ip_mc_list *pmc;
1969         int     isexclude;
1970         int     i, err;
1971 
1972         if (!in_dev)
1973                 return -ENODEV;
1974         rcu_read_lock();
1975         for_each_pmc_rcu(in_dev, pmc) {
1976                 if (*pmca == pmc->multiaddr)
1977                         break;
1978         }
1979         if (!pmc) {
1980                 /* MCA not found?? bug */
1981                 rcu_read_unlock();
1982                 return -ESRCH;
1983         }
1984         spin_lock_bh(&pmc->lock);
1985         rcu_read_unlock();
1986 
1987 #ifdef CONFIG_IP_MULTICAST
1988         sf_markstate(pmc);
1989 #endif
1990         isexclude = pmc->sfmode == MCAST_EXCLUDE;
1991         if (!delta)
1992                 pmc->sfcount[sfmode]++;
1993         err = 0;
1994         for (i = 0; i < sfcount; i++) {
1995                 err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
1996                 if (err)
1997                         break;
1998         }
1999         if (err) {
2000                 int j;
2001 
2002                 if (!delta)
2003                         pmc->sfcount[sfmode]--;
2004                 for (j = 0; j < i; j++)
2005                         (void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2006         } else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
2007 #ifdef CONFIG_IP_MULTICAST
2008                 struct ip_sf_list *psf;
2009                 struct net *net = dev_net(pmc->interface->dev);
2010                 in_dev = pmc->interface;
2011 #endif
2012 
2013                 /* filter mode change */
2014                 if (pmc->sfcount[MCAST_EXCLUDE])
2015                         pmc->sfmode = MCAST_EXCLUDE;
2016                 else if (pmc->sfcount[MCAST_INCLUDE])
2017                         pmc->sfmode = MCAST_INCLUDE;
2018 #ifdef CONFIG_IP_MULTICAST
2019                 /* else no filters; keep old mode for reports */
2020 
2021                 pmc->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
2022                 in_dev->mr_ifc_count = pmc->crcount;
2023                 for (psf = pmc->sources; psf; psf = psf->sf_next)
2024                         psf->sf_crcount = 0;
2025                 igmp_ifc_event(in_dev);
2026         } else if (sf_setstate(pmc)) {
2027                 igmp_ifc_event(in_dev);
2028 #endif
2029         }
2030         spin_unlock_bh(&pmc->lock);
2031         return err;
2032 }
2033 
2034 static void ip_mc_clear_src(struct ip_mc_list *pmc)
2035 {
2036         struct ip_sf_list *psf, *nextpsf;
2037 
2038         for (psf = pmc->tomb; psf; psf = nextpsf) {
2039                 nextpsf = psf->sf_next;
2040                 kfree(psf);
2041         }
2042         pmc->tomb = NULL;
2043         for (psf = pmc->sources; psf; psf = nextpsf) {
2044                 nextpsf = psf->sf_next;
2045                 kfree(psf);
2046         }
2047         pmc->sources = NULL;
2048         pmc->sfmode = MCAST_EXCLUDE;
2049         pmc->sfcount[MCAST_INCLUDE] = 0;
2050         pmc->sfcount[MCAST_EXCLUDE] = 1;
2051 }
2052 
2053 /* Join a multicast group
2054  */
2055 
2056 int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
2057 {
2058         __be32 addr = imr->imr_multiaddr.s_addr;
2059         struct ip_mc_socklist *iml, *i;
2060         struct in_device *in_dev;
2061         struct inet_sock *inet = inet_sk(sk);
2062         struct net *net = sock_net(sk);
2063         int ifindex;
2064         int count = 0;
2065         int err;
2066 
2067         ASSERT_RTNL();
2068 
2069         if (!ipv4_is_multicast(addr))
2070                 return -EINVAL;
2071 
2072         in_dev = ip_mc_find_dev(net, imr);
2073 
2074         if (!in_dev) {
2075                 err = -ENODEV;
2076                 goto done;
2077         }
2078 
2079         err = -EADDRINUSE;
2080         ifindex = imr->imr_ifindex;
2081         for_each_pmc_rtnl(inet, i) {
2082                 if (i->multi.imr_multiaddr.s_addr == addr &&
2083                     i->multi.imr_ifindex == ifindex)
2084                         goto done;
2085                 count++;
2086         }
2087         err = -ENOBUFS;
2088         if (count >= net->ipv4.sysctl_igmp_max_memberships)
2089                 goto done;
2090         iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
2091         if (!iml)
2092                 goto done;
2093 
2094         memcpy(&iml->multi, imr, sizeof(*imr));
2095         iml->next_rcu = inet->mc_list;
2096         iml->sflist = NULL;
2097         iml->sfmode = MCAST_EXCLUDE;
2098         rcu_assign_pointer(inet->mc_list, iml);
2099         ip_mc_inc_group(in_dev, addr);
2100         err = 0;
2101 done:
2102         return err;
2103 }
2104 EXPORT_SYMBOL(ip_mc_join_group);
2105 
2106 static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
2107                            struct in_device *in_dev)
2108 {
2109         struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
2110         int err;
2111 
2112         if (!psf) {
2113                 /* any-source empty exclude case */
2114                 return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2115                         iml->sfmode, 0, NULL, 0);
2116         }
2117         err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
2118                         iml->sfmode, psf->sl_count, psf->sl_addr, 0);
2119         RCU_INIT_POINTER(iml->sflist, NULL);
2120         /* decrease mem now to avoid the memleak warning */
2121         atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
2122         kfree_rcu(psf, rcu);
2123         return err;
2124 }
2125 
2126 int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
2127 {
2128         struct inet_sock *inet = inet_sk(sk);
2129         struct ip_mc_socklist *iml;
2130         struct ip_mc_socklist __rcu **imlp;
2131         struct in_device *in_dev;
2132         struct net *net = sock_net(sk);
2133         __be32 group = imr->imr_multiaddr.s_addr;
2134         u32 ifindex;
2135         int ret = -EADDRNOTAVAIL;
2136 
2137         ASSERT_RTNL();
2138 
2139         in_dev = ip_mc_find_dev(net, imr);
2140         if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
2141                 ret = -ENODEV;
2142                 goto out;
2143         }
2144         ifindex = imr->imr_ifindex;
2145         for (imlp = &inet->mc_list;
2146              (iml = rtnl_dereference(*imlp)) != NULL;
2147              imlp = &iml->next_rcu) {
2148                 if (iml->multi.imr_multiaddr.s_addr != group)
2149                         continue;
2150                 if (ifindex) {
2151                         if (iml->multi.imr_ifindex != ifindex)
2152                                 continue;
2153                 } else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
2154                                 iml->multi.imr_address.s_addr)
2155                         continue;
2156 
2157                 (void) ip_mc_leave_src(sk, iml, in_dev);
2158 
2159                 *imlp = iml->next_rcu;
2160 
2161                 if (in_dev)
2162                         ip_mc_dec_group(in_dev, group);
2163 
2164                 /* decrease mem now to avoid the memleak warning */
2165                 atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2166                 kfree_rcu(iml, rcu);
2167                 return 0;
2168         }
2169 out:
2170         return ret;
2171 }
2172 EXPORT_SYMBOL(ip_mc_leave_group);
2173 
2174 int ip_mc_source(int add, int omode, struct sock *sk, struct
2175         ip_mreq_source *mreqs, int ifindex)
2176 {
2177         int err;
2178         struct ip_mreqn imr;
2179         __be32 addr = mreqs->imr_multiaddr;
2180         struct ip_mc_socklist *pmc;
2181         struct in_device *in_dev = NULL;
2182         struct inet_sock *inet = inet_sk(sk);
2183         struct ip_sf_socklist *psl;
2184         struct net *net = sock_net(sk);
2185         int leavegroup = 0;
2186         int i, j, rv;
2187 
2188         if (!ipv4_is_multicast(addr))
2189                 return -EINVAL;
2190 
2191         ASSERT_RTNL();
2192 
2193         imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
2194         imr.imr_address.s_addr = mreqs->imr_interface;
2195         imr.imr_ifindex = ifindex;
2196         in_dev = ip_mc_find_dev(net, &imr);
2197 
2198         if (!in_dev) {
2199                 err = -ENODEV;
2200                 goto done;
2201         }
2202         err = -EADDRNOTAVAIL;
2203 
2204         for_each_pmc_rtnl(inet, pmc) {
2205                 if ((pmc->multi.imr_multiaddr.s_addr ==
2206                      imr.imr_multiaddr.s_addr) &&
2207                     (pmc->multi.imr_ifindex == imr.imr_ifindex))
2208                         break;
2209         }
2210         if (!pmc) {             /* must have a prior join */
2211                 err = -EINVAL;
2212                 goto done;
2213         }
2214         /* if a source filter was set, must be the same mode as before */
2215         if (pmc->sflist) {
2216                 if (pmc->sfmode != omode) {
2217                         err = -EINVAL;
2218                         goto done;
2219                 }
2220         } else if (pmc->sfmode != omode) {
2221                 /* allow mode switches for empty-set filters */
2222                 ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
2223                 ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
2224                         NULL, 0);
2225                 pmc->sfmode = omode;
2226         }
2227 
2228         psl = rtnl_dereference(pmc->sflist);
2229         if (!add) {
2230                 if (!psl)
2231                         goto done;      /* err = -EADDRNOTAVAIL */
2232                 rv = !0;
2233                 for (i = 0; i < psl->sl_count; i++) {
2234                         rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2235                                 sizeof(__be32));
2236                         if (rv == 0)
2237                                 break;
2238                 }
2239                 if (rv)         /* source not found */
2240                         goto done;      /* err = -EADDRNOTAVAIL */
2241 
2242                 /* special case - (INCLUDE, empty) == LEAVE_GROUP */
2243                 if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
2244                         leavegroup = 1;
2245                         goto done;
2246                 }
2247 
2248                 /* update the interface filter */
2249                 ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2250                         &mreqs->imr_sourceaddr, 1);
2251 
2252                 for (j = i+1; j < psl->sl_count; j++)
2253                         psl->sl_addr[j-1] = psl->sl_addr[j];
2254                 psl->sl_count--;
2255                 err = 0;
2256                 goto done;
2257         }
2258         /* else, add a new source to the filter */
2259 
2260         if (psl && psl->sl_count >= net->ipv4.sysctl_igmp_max_msf) {
2261                 err = -ENOBUFS;
2262                 goto done;
2263         }
2264         if (!psl || psl->sl_count == psl->sl_max) {
2265                 struct ip_sf_socklist *newpsl;
2266                 int count = IP_SFBLOCK;
2267 
2268                 if (psl)
2269                         count += psl->sl_max;
2270                 newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
2271                 if (!newpsl) {
2272                         err = -ENOBUFS;
2273                         goto done;
2274                 }
2275                 newpsl->sl_max = count;
2276                 newpsl->sl_count = count - IP_SFBLOCK;
2277                 if (psl) {
2278                         for (i = 0; i < psl->sl_count; i++)
2279                                 newpsl->sl_addr[i] = psl->sl_addr[i];
2280                         /* decrease mem now to avoid the memleak warning */
2281                         atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2282                         kfree_rcu(psl, rcu);
2283                 }
2284                 rcu_assign_pointer(pmc->sflist, newpsl);
2285                 psl = newpsl;
2286         }
2287         rv = 1; /* > 0 for insert logic below if sl_count is 0 */
2288         for (i = 0; i < psl->sl_count; i++) {
2289                 rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
2290                         sizeof(__be32));
2291                 if (rv == 0)
2292                         break;
2293         }
2294         if (rv == 0)            /* address already there is an error */
2295                 goto done;
2296         for (j = psl->sl_count-1; j >= i; j--)
2297                 psl->sl_addr[j+1] = psl->sl_addr[j];
2298         psl->sl_addr[i] = mreqs->imr_sourceaddr;
2299         psl->sl_count++;
2300         err = 0;
2301         /* update the interface list */
2302         ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
2303                 &mreqs->imr_sourceaddr, 1);
2304 done:
2305         if (leavegroup)
2306                 err = ip_mc_leave_group(sk, &imr);
2307         return err;
2308 }
2309 
2310 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
2311 {
2312         int err = 0;
2313         struct ip_mreqn imr;
2314         __be32 addr = msf->imsf_multiaddr;
2315         struct ip_mc_socklist *pmc;
2316         struct in_device *in_dev;
2317         struct inet_sock *inet = inet_sk(sk);
2318         struct ip_sf_socklist *newpsl, *psl;
2319         struct net *net = sock_net(sk);
2320         int leavegroup = 0;
2321 
2322         if (!ipv4_is_multicast(addr))
2323                 return -EINVAL;
2324         if (msf->imsf_fmode != MCAST_INCLUDE &&
2325             msf->imsf_fmode != MCAST_EXCLUDE)
2326                 return -EINVAL;
2327 
2328         ASSERT_RTNL();
2329 
2330         imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2331         imr.imr_address.s_addr = msf->imsf_interface;
2332         imr.imr_ifindex = ifindex;
2333         in_dev = ip_mc_find_dev(net, &imr);
2334 
2335         if (!in_dev) {
2336                 err = -ENODEV;
2337                 goto done;
2338         }
2339 
2340         /* special case - (INCLUDE, empty) == LEAVE_GROUP */
2341         if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
2342                 leavegroup = 1;
2343                 goto done;
2344         }
2345 
2346         for_each_pmc_rtnl(inet, pmc) {
2347                 if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2348                     pmc->multi.imr_ifindex == imr.imr_ifindex)
2349                         break;
2350         }
2351         if (!pmc) {             /* must have a prior join */
2352                 err = -EINVAL;
2353                 goto done;
2354         }
2355         if (msf->imsf_numsrc) {
2356                 newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
2357                                                            GFP_KERNEL);
2358                 if (!newpsl) {
2359                         err = -ENOBUFS;
2360                         goto done;
2361                 }
2362                 newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
2363                 memcpy(newpsl->sl_addr, msf->imsf_slist,
2364                         msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
2365                 err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2366                         msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
2367                 if (err) {
2368                         sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
2369                         goto done;
2370                 }
2371         } else {
2372                 newpsl = NULL;
2373                 (void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
2374                                      msf->imsf_fmode, 0, NULL, 0);
2375         }
2376         psl = rtnl_dereference(pmc->sflist);
2377         if (psl) {
2378                 (void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2379                         psl->sl_count, psl->sl_addr, 0);
2380                 /* decrease mem now to avoid the memleak warning */
2381                 atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
2382                 kfree_rcu(psl, rcu);
2383         } else
2384                 (void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
2385                         0, NULL, 0);
2386         rcu_assign_pointer(pmc->sflist, newpsl);
2387         pmc->sfmode = msf->imsf_fmode;
2388         err = 0;
2389 done:
2390         if (leavegroup)
2391                 err = ip_mc_leave_group(sk, &imr);
2392         return err;
2393 }
2394 
2395 int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
2396         struct ip_msfilter __user *optval, int __user *optlen)
2397 {
2398         int err, len, count, copycount;
2399         struct ip_mreqn imr;
2400         __be32 addr = msf->imsf_multiaddr;
2401         struct ip_mc_socklist *pmc;
2402         struct in_device *in_dev;
2403         struct inet_sock *inet = inet_sk(sk);
2404         struct ip_sf_socklist *psl;
2405         struct net *net = sock_net(sk);
2406 
2407         ASSERT_RTNL();
2408 
2409         if (!ipv4_is_multicast(addr))
2410                 return -EINVAL;
2411 
2412         imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
2413         imr.imr_address.s_addr = msf->imsf_interface;
2414         imr.imr_ifindex = 0;
2415         in_dev = ip_mc_find_dev(net, &imr);
2416 
2417         if (!in_dev) {
2418                 err = -ENODEV;
2419                 goto done;
2420         }
2421         err = -EADDRNOTAVAIL;
2422 
2423         for_each_pmc_rtnl(inet, pmc) {
2424                 if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
2425                     pmc->multi.imr_ifindex == imr.imr_ifindex)
2426                         break;
2427         }
2428         if (!pmc)               /* must have a prior join */
2429                 goto done;
2430         msf->imsf_fmode = pmc->sfmode;
2431         psl = rtnl_dereference(pmc->sflist);
2432         if (!psl) {
2433                 len = 0;
2434                 count = 0;
2435         } else {
2436                 count = psl->sl_count;
2437         }
2438         copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
2439         len = copycount * sizeof(psl->sl_addr[0]);
2440         msf->imsf_numsrc = count;
2441         if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
2442             copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
2443                 return -EFAULT;
2444         }
2445         if (len &&
2446             copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
2447                 return -EFAULT;
2448         return 0;
2449 done:
2450         return err;
2451 }
2452 
2453 int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
2454         struct group_filter __user *optval, int __user *optlen)
2455 {
2456         int err, i, count, copycount;
2457         struct sockaddr_in *psin;
2458         __be32 addr;
2459         struct ip_mc_socklist *pmc;
2460         struct inet_sock *inet = inet_sk(sk);
2461         struct ip_sf_socklist *psl;
2462 
2463         ASSERT_RTNL();
2464 
2465         psin = (struct sockaddr_in *)&gsf->gf_group;
2466         if (psin->sin_family != AF_INET)
2467                 return -EINVAL;
2468         addr = psin->sin_addr.s_addr;
2469         if (!ipv4_is_multicast(addr))
2470                 return -EINVAL;
2471 
2472         err = -EADDRNOTAVAIL;
2473 
2474         for_each_pmc_rtnl(inet, pmc) {
2475                 if (pmc->multi.imr_multiaddr.s_addr == addr &&
2476                     pmc->multi.imr_ifindex == gsf->gf_interface)
2477                         break;
2478         }
2479         if (!pmc)               /* must have a prior join */
2480                 goto done;
2481         gsf->gf_fmode = pmc->sfmode;
2482         psl = rtnl_dereference(pmc->sflist);
2483         count = psl ? psl->sl_count : 0;
2484         copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
2485         gsf->gf_numsrc = count;
2486         if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
2487             copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
2488                 return -EFAULT;
2489         }
2490         for (i = 0; i < copycount; i++) {
2491                 struct sockaddr_storage ss;
2492 
2493                 psin = (struct sockaddr_in *)&ss;
2494                 memset(&ss, 0, sizeof(ss));
2495                 psin->sin_family = AF_INET;
2496                 psin->sin_addr.s_addr = psl->sl_addr[i];
2497                 if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
2498                         return -EFAULT;
2499         }
2500         return 0;
2501 done:
2502         return err;
2503 }
2504 
2505 /*
2506  * check if a multicast source filter allows delivery for a given <src,dst,intf>
2507  */
2508 int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
2509 {
2510         struct inet_sock *inet = inet_sk(sk);
2511         struct ip_mc_socklist *pmc;
2512         struct ip_sf_socklist *psl;
2513         int i;
2514         int ret;
2515 
2516         ret = 1;
2517         if (!ipv4_is_multicast(loc_addr))
2518                 goto out;
2519 
2520         rcu_read_lock();
2521         for_each_pmc_rcu(inet, pmc) {
2522                 if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
2523                     pmc->multi.imr_ifindex == dif)
2524                         break;
2525         }
2526         ret = inet->mc_all;
2527         if (!pmc)
2528                 goto unlock;
2529         psl = rcu_dereference(pmc->sflist);
2530         ret = (pmc->sfmode == MCAST_EXCLUDE);
2531         if (!psl)
2532                 goto unlock;
2533 
2534         for (i = 0; i < psl->sl_count; i++) {
2535                 if (psl->sl_addr[i] == rmt_addr)
2536                         break;
2537         }
2538         ret = 0;
2539         if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
2540                 goto unlock;
2541         if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
2542                 goto unlock;
2543         ret = 1;
2544 unlock:
2545         rcu_read_unlock();
2546 out:
2547         return ret;
2548 }
2549 
2550 /*
2551  *      A socket is closing.
2552  */
2553 
2554 void ip_mc_drop_socket(struct sock *sk)
2555 {
2556         struct inet_sock *inet = inet_sk(sk);
2557         struct ip_mc_socklist *iml;
2558         struct net *net = sock_net(sk);
2559 
2560         if (!inet->mc_list)
2561                 return;
2562 
2563         rtnl_lock();
2564         while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
2565                 struct in_device *in_dev;
2566 
2567                 inet->mc_list = iml->next_rcu;
2568                 in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
2569                 (void) ip_mc_leave_src(sk, iml, in_dev);
2570                 if (in_dev)
2571                         ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
2572                 /* decrease mem now to avoid the memleak warning */
2573                 atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
2574                 kfree_rcu(iml, rcu);
2575         }
2576         rtnl_unlock();
2577 }
2578 
2579 /* called with rcu_read_lock() */
2580 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
2581 {
2582         struct ip_mc_list *im;
2583         struct ip_mc_list __rcu **mc_hash;
2584         struct ip_sf_list *psf;
2585         int rv = 0;
2586 
2587         mc_hash = rcu_dereference(in_dev->mc_hash);
2588         if (mc_hash) {
2589                 u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
2590 
2591                 for (im = rcu_dereference(mc_hash[hash]);
2592                      im != NULL;
2593                      im = rcu_dereference(im->next_hash)) {
2594                         if (im->multiaddr == mc_addr)
2595                                 break;
2596                 }
2597         } else {
2598                 for_each_pmc_rcu(in_dev, im) {
2599                         if (im->multiaddr == mc_addr)
2600                                 break;
2601                 }
2602         }
2603         if (im && proto == IPPROTO_IGMP) {
2604                 rv = 1;
2605         } else if (im) {
2606                 if (src_addr) {
2607                         for (psf = im->sources; psf; psf = psf->sf_next) {
2608                                 if (psf->sf_inaddr == src_addr)
2609                                         break;
2610                         }
2611                         if (psf)
2612                                 rv = psf->sf_count[MCAST_INCLUDE] ||
2613                                         psf->sf_count[MCAST_EXCLUDE] !=
2614                                         im->sfcount[MCAST_EXCLUDE];
2615                         else
2616                                 rv = im->sfcount[MCAST_EXCLUDE] != 0;
2617                 } else
2618                         rv = 1; /* unspecified source; tentatively allow */
2619         }
2620         return rv;
2621 }
2622 
2623 #if defined(CONFIG_PROC_FS)
2624 struct igmp_mc_iter_state {
2625         struct seq_net_private p;
2626         struct net_device *dev;
2627         struct in_device *in_dev;
2628 };
2629 
2630 #define igmp_mc_seq_private(seq)        ((struct igmp_mc_iter_state *)(seq)->private)
2631 
2632 static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
2633 {
2634         struct net *net = seq_file_net(seq);
2635         struct ip_mc_list *im = NULL;
2636         struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2637 
2638         state->in_dev = NULL;
2639         for_each_netdev_rcu(net, state->dev) {
2640                 struct in_device *in_dev;
2641 
2642                 in_dev = __in_dev_get_rcu(state->dev);
2643                 if (!in_dev)
2644                         continue;
2645                 im = rcu_dereference(in_dev->mc_list);
2646                 if (im) {
2647                         state->in_dev = in_dev;
2648                         break;
2649                 }
2650         }
2651         return im;
2652 }
2653 
2654 static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
2655 {
2656         struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2657 
2658         im = rcu_dereference(im->next_rcu);
2659         while (!im) {
2660                 state->dev = next_net_device_rcu(state->dev);
2661                 if (!state->dev) {
2662                         state->in_dev = NULL;
2663                         break;
2664                 }
2665                 state->in_dev = __in_dev_get_rcu(state->dev);
2666                 if (!state->in_dev)
2667                         continue;
2668                 im = rcu_dereference(state->in_dev->mc_list);
2669         }
2670         return im;
2671 }
2672 
2673 static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
2674 {
2675         struct ip_mc_list *im = igmp_mc_get_first(seq);
2676         if (im)
2677                 while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
2678                         --pos;
2679         return pos ? NULL : im;
2680 }
2681 
2682 static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
2683         __acquires(rcu)
2684 {
2685         rcu_read_lock();
2686         return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2687 }
2688 
2689 static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2690 {
2691         struct ip_mc_list *im;
2692         if (v == SEQ_START_TOKEN)
2693                 im = igmp_mc_get_first(seq);
2694         else
2695                 im = igmp_mc_get_next(seq, v);
2696         ++*pos;
2697         return im;
2698 }
2699 
2700 static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
2701         __releases(rcu)
2702 {
2703         struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2704 
2705         state->in_dev = NULL;
2706         state->dev = NULL;
2707         rcu_read_unlock();
2708 }
2709 
2710 static int igmp_mc_seq_show(struct seq_file *seq, void *v)
2711 {
2712         if (v == SEQ_START_TOKEN)
2713                 seq_puts(seq,
2714                          "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
2715         else {
2716                 struct ip_mc_list *im = (struct ip_mc_list *)v;
2717                 struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
2718                 char   *querier;
2719                 long delta;
2720 
2721 #ifdef CONFIG_IP_MULTICAST
2722                 querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
2723                           IGMP_V2_SEEN(state->in_dev) ? "V2" :
2724                           "V3";
2725 #else
2726                 querier = "NONE";
2727 #endif
2728 
2729                 if (rcu_access_pointer(state->in_dev->mc_list) == im) {
2730                         seq_printf(seq, "%d\t%-10s: %5d %7s\n",
2731                                    state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
2732                 }
2733 
2734                 delta = im->timer.expires - jiffies;
2735                 seq_printf(seq,
2736                            "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
2737                            im->multiaddr, im->users,
2738                            im->tm_running,
2739                            im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
2740                            im->reporter);
2741         }
2742         return 0;
2743 }
2744 
2745 static const struct seq_operations igmp_mc_seq_ops = {
2746         .start  =       igmp_mc_seq_start,
2747         .next   =       igmp_mc_seq_next,
2748         .stop   =       igmp_mc_seq_stop,
2749         .show   =       igmp_mc_seq_show,
2750 };
2751 
2752 static int igmp_mc_seq_open(struct inode *inode, struct file *file)
2753 {
2754         return seq_open_net(inode, file, &igmp_mc_seq_ops,
2755                         sizeof(struct igmp_mc_iter_state));
2756 }
2757 
2758 static const struct file_operations igmp_mc_seq_fops = {
2759         .owner          =       THIS_MODULE,
2760         .open           =       igmp_mc_seq_open,
2761         .read           =       seq_read,
2762         .llseek         =       seq_lseek,
2763         .release        =       seq_release_net,
2764 };
2765 
2766 struct igmp_mcf_iter_state {
2767         struct seq_net_private p;
2768         struct net_device *dev;
2769         struct in_device *idev;
2770         struct ip_mc_list *im;
2771 };
2772 
2773 #define igmp_mcf_seq_private(seq)       ((struct igmp_mcf_iter_state *)(seq)->private)
2774 
2775 static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
2776 {
2777         struct net *net = seq_file_net(seq);
2778         struct ip_sf_list *psf = NULL;
2779         struct ip_mc_list *im = NULL;
2780         struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2781 
2782         state->idev = NULL;
2783         state->im = NULL;
2784         for_each_netdev_rcu(net, state->dev) {
2785                 struct in_device *idev;
2786                 idev = __in_dev_get_rcu(state->dev);
2787                 if (unlikely(!idev))
2788                         continue;
2789                 im = rcu_dereference(idev->mc_list);
2790                 if (likely(im)) {
2791                         spin_lock_bh(&im->lock);
2792                         psf = im->sources;
2793                         if (likely(psf)) {
2794                                 state->im = im;
2795                                 state->idev = idev;
2796                                 break;
2797                         }
2798                         spin_unlock_bh(&im->lock);
2799                 }
2800         }
2801         return psf;
2802 }
2803 
2804 static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
2805 {
2806         struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2807 
2808         psf = psf->sf_next;
2809         while (!psf) {
2810                 spin_unlock_bh(&state->im->lock);
2811                 state->im = state->im->next;
2812                 while (!state->im) {
2813                         state->dev = next_net_device_rcu(state->dev);
2814                         if (!state->dev) {
2815                                 state->idev = NULL;
2816                                 goto out;
2817                         }
2818                         state->idev = __in_dev_get_rcu(state->dev);
2819                         if (!state->idev)
2820                                 continue;
2821                         state->im = rcu_dereference(state->idev->mc_list);
2822                 }
2823                 if (!state->im)
2824                         break;
2825                 spin_lock_bh(&state->im->lock);
2826                 psf = state->im->sources;
2827         }
2828 out:
2829         return psf;
2830 }
2831 
2832 static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
2833 {
2834         struct ip_sf_list *psf = igmp_mcf_get_first(seq);
2835         if (psf)
2836                 while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
2837                         --pos;
2838         return pos ? NULL : psf;
2839 }
2840 
2841 static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2842         __acquires(rcu)
2843 {
2844         rcu_read_lock();
2845         return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2846 }
2847 
2848 static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2849 {
2850         struct ip_sf_list *psf;
2851         if (v == SEQ_START_TOKEN)
2852                 psf = igmp_mcf_get_first(seq);
2853         else
2854                 psf = igmp_mcf_get_next(seq, v);
2855         ++*pos;
2856         return psf;
2857 }
2858 
2859 static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
2860         __releases(rcu)
2861 {
2862         struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2863         if (likely(state->im)) {
2864                 spin_unlock_bh(&state->im->lock);
2865                 state->im = NULL;
2866         }
2867         state->idev = NULL;
2868         state->dev = NULL;
2869         rcu_read_unlock();
2870 }
2871 
2872 static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
2873 {
2874         struct ip_sf_list *psf = (struct ip_sf_list *)v;
2875         struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
2876 
2877         if (v == SEQ_START_TOKEN) {
2878                 seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
2879         } else {
2880                 seq_printf(seq,
2881                            "%3d %6.6s 0x%08x "
2882                            "0x%08x %6lu %6lu\n",
2883                            state->dev->ifindex, state->dev->name,
2884                            ntohl(state->im->multiaddr),
2885                            ntohl(psf->sf_inaddr),
2886                            psf->sf_count[MCAST_INCLUDE],
2887                            psf->sf_count[MCAST_EXCLUDE]);
2888         }
2889         return 0;
2890 }
2891 
2892 static const struct seq_operations igmp_mcf_seq_ops = {
2893         .start  =       igmp_mcf_seq_start,
2894         .next   =       igmp_mcf_seq_next,
2895         .stop   =       igmp_mcf_seq_stop,
2896         .show   =       igmp_mcf_seq_show,
2897 };
2898 
2899 static int igmp_mcf_seq_open(struct inode *inode, struct file *file)
2900 {
2901         return seq_open_net(inode, file, &igmp_mcf_seq_ops,
2902                         sizeof(struct igmp_mcf_iter_state));
2903 }
2904 
2905 static const struct file_operations igmp_mcf_seq_fops = {
2906         .owner          =       THIS_MODULE,
2907         .open           =       igmp_mcf_seq_open,
2908         .read           =       seq_read,
2909         .llseek         =       seq_lseek,
2910         .release        =       seq_release_net,
2911 };
2912 
2913 static int __net_init igmp_net_init(struct net *net)
2914 {
2915         struct proc_dir_entry *pde;
2916         int err;
2917 
2918         pde = proc_create("igmp", S_IRUGO, net->proc_net, &igmp_mc_seq_fops);
2919         if (!pde)
2920                 goto out_igmp;
2921         pde = proc_create("mcfilter", S_IRUGO, net->proc_net,
2922                           &igmp_mcf_seq_fops);
2923         if (!pde)
2924                 goto out_mcfilter;
2925         err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
2926                                    SOCK_DGRAM, 0, net);
2927         if (err < 0) {
2928                 pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
2929                        err);
2930                 goto out_sock;
2931         }
2932 
2933         /* Sysctl initialization */
2934         net->ipv4.sysctl_igmp_max_memberships = 20;
2935         net->ipv4.sysctl_igmp_max_msf = 10;
2936         /* IGMP reports for link-local multicast groups are enabled by default */
2937         net->ipv4.sysctl_igmp_llm_reports = 1;
2938         net->ipv4.sysctl_igmp_qrv = 2;
2939         return 0;
2940 
2941 out_sock:
2942         remove_proc_entry("mcfilter", net->proc_net);
2943 out_mcfilter:
2944         remove_proc_entry("igmp", net->proc_net);
2945 out_igmp:
2946         return -ENOMEM;
2947 }
2948 
2949 static void __net_exit igmp_net_exit(struct net *net)
2950 {
2951         remove_proc_entry("mcfilter", net->proc_net);
2952         remove_proc_entry("igmp", net->proc_net);
2953         inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
2954 }
2955 
2956 static struct pernet_operations igmp_net_ops = {
2957         .init = igmp_net_init,
2958         .exit = igmp_net_exit,
2959 };
2960 #endif
2961 
2962 static int igmp_netdev_event(struct notifier_block *this,
2963                              unsigned long event, void *ptr)
2964 {
2965         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2966         struct in_device *in_dev;
2967 
2968         switch (event) {
2969         case NETDEV_RESEND_IGMP:
2970                 in_dev = __in_dev_get_rtnl(dev);
2971                 if (in_dev)
2972                         ip_mc_rejoin_groups(in_dev);
2973                 break;
2974         default:
2975                 break;
2976         }
2977         return NOTIFY_DONE;
2978 }
2979 
2980 static struct notifier_block igmp_notifier = {
2981         .notifier_call = igmp_netdev_event,
2982 };
2983 
2984 int __init igmp_mc_init(void)
2985 {
2986 #if defined(CONFIG_PROC_FS)
2987         int err;
2988 
2989         err = register_pernet_subsys(&igmp_net_ops);
2990         if (err)
2991                 return err;
2992         err = register_netdevice_notifier(&igmp_notifier);
2993         if (err)
2994                 goto reg_notif_fail;
2995         return 0;
2996 
2997 reg_notif_fail:
2998         unregister_pernet_subsys(&igmp_net_ops);
2999         return err;
3000 #else
3001         return register_netdevice_notifier(&igmp_notifier);
3002 #endif
3003 }
3004 

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