FreeBSD/Linux Kernel Cross Reference
sys/netinet6/mld6.c
1 /* $FreeBSD: src/sys/netinet6/mld6.c,v 1.17.2.3 2006/01/18 23:36:49 emaste Exp $ */
2 /* $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $ */
3
4 /*-
5 * Copyright (C) 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 /*-
34 * Copyright (c) 1988 Stephen Deering.
35 * Copyright (c) 1992, 1993
36 * The Regents of the University of California. All rights reserved.
37 *
38 * This code is derived from software contributed to Berkeley by
39 * Stephen Deering of Stanford University.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 * 4. Neither the name of the University nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
65 * @(#)igmp.c 8.1 (Berkeley) 7/19/93
66 */
67
68 #include "opt_inet.h"
69 #include "opt_inet6.h"
70
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/mbuf.h>
74 #include <sys/socket.h>
75 #include <sys/protosw.h>
76 #include <sys/syslog.h>
77 #include <sys/malloc.h>
78
79 #include <net/if.h>
80
81 #include <netinet/in.h>
82 #include <netinet/in_var.h>
83 #include <netinet/ip6.h>
84 #include <netinet6/ip6_var.h>
85 #include <netinet/icmp6.h>
86 #include <netinet6/mld6_var.h>
87
88 #include <net/net_osdep.h>
89
90 /*
91 * Protocol constants
92 */
93
94 /* denotes that the MLD max response delay field specifies time in milliseconds */
95 #define MLD_TIMER_SCALE 1000
96 /*
97 * time between repetitions of a node's initial report of interest in a
98 * multicast address(in seconds)
99 */
100 #define MLD_UNSOLICITED_REPORT_INTERVAL 10
101
102 static struct ip6_pktopts ip6_opts;
103 static int mld6_timers_are_running;
104 /* XXX: These are necessary for KAME's link-local hack */
105 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
106 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
107
108 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
109
110 void
111 mld6_init()
112 {
113 static u_int8_t hbh_buf[8];
114 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
115 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
116
117 mld6_timers_are_running = 0;
118
119 /* ip6h_nxt will be fill in later */
120 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */
121
122 /* XXX: grotty hard coding... */
123 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
124 hbh_buf[3] = 0;
125 hbh_buf[4] = IP6OPT_ROUTER_ALERT;
126 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
127 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
128
129 ip6_initpktopts(&ip6_opts);
130 ip6_opts.ip6po_hbh = hbh;
131 }
132
133 void
134 mld6_start_listening(in6m)
135 struct in6_multi *in6m;
136 {
137 int s = splnet();
138
139 /*
140 * RFC2710 page 10:
141 * The node never sends a Report or Done for the link-scope all-nodes
142 * address.
143 * MLD messages are never sent for multicast addresses whose scope is 0
144 * (reserved) or 1 (node-local).
145 */
146 mld6_all_nodes_linklocal.s6_addr16[1] =
147 htons(in6m->in6m_ifp->if_index); /* XXX */
148 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
149 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
150 in6m->in6m_timer = 0;
151 in6m->in6m_state = MLD_OTHERLISTENER;
152 } else {
153 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
154 in6m->in6m_timer =
155 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL *
156 PR_FASTHZ);
157 in6m->in6m_state = MLD_IREPORTEDLAST;
158 mld6_timers_are_running = 1;
159 }
160 splx(s);
161 }
162
163 void
164 mld6_stop_listening(in6m)
165 struct in6_multi *in6m;
166 {
167 mld6_all_nodes_linklocal.s6_addr16[1] =
168 htons(in6m->in6m_ifp->if_index); /* XXX */
169 mld6_all_routers_linklocal.s6_addr16[1] =
170 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
171
172 if (in6m->in6m_state == MLD_IREPORTEDLAST &&
173 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
174 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL)
175 mld6_sendpkt(in6m, MLD_LISTENER_DONE,
176 &mld6_all_routers_linklocal);
177 }
178
179 void
180 mld6_input(m, off)
181 struct mbuf *m;
182 int off;
183 {
184 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
185 struct mld_hdr *mldh;
186 struct ifnet *ifp = m->m_pkthdr.rcvif;
187 struct in6_multi *in6m;
188 struct in6_ifaddr *ia;
189 struct ifmultiaddr *ifma;
190 int timer; /* timer value in the MLD query header */
191
192 #ifndef PULLDOWN_TEST
193 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
194 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
195 #else
196 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
197 if (mldh == NULL) {
198 icmp6stat.icp6s_tooshort++;
199 return;
200 }
201 #endif
202
203 /* source address validation */
204 ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */
205 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
206 log(LOG_ERR,
207 "mld6_input: src %s is not link-local (grp=%s)\n",
208 ip6_sprintf(&ip6->ip6_src),
209 ip6_sprintf(&mldh->mld_addr));
210 /*
211 * spec (RFC2710) does not explicitly
212 * specify to discard the packet from a non link-local
213 * source address. But we believe it's expected to do so.
214 * XXX: do we have to allow :: as source?
215 */
216 m_freem(m);
217 return;
218 }
219
220 /*
221 * In the MLD6 specification, there are 3 states and a flag.
222 *
223 * In Non-Listener state, we simply don't have a membership record.
224 * In Delaying Listener state, our timer is running (in6m->in6m_timer)
225 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
226 *
227 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if
228 * we have heard a report from another member, or MLD_IREPORTEDLAST
229 * if we sent the last report.
230 */
231 switch(mldh->mld_type) {
232 case MLD_LISTENER_QUERY:
233 if (ifp->if_flags & IFF_LOOPBACK)
234 break;
235
236 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
237 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
238 break; /* print error or log stat? */
239 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
240 mldh->mld_addr.s6_addr16[1] =
241 htons(ifp->if_index); /* XXX */
242
243 /*
244 * - Start the timers in all of our membership records
245 * that the query applies to for the interface on
246 * which the query arrived excl. those that belong
247 * to the "all-nodes" group (ff02::1).
248 * - Restart any timer that is already running but has
249 * A value longer than the requested timeout.
250 * - Use the value specified in the query message as
251 * the maximum timeout.
252 */
253 IFP_TO_IA6(ifp, ia);
254 if (ia == NULL)
255 break;
256
257 /*
258 * XXX: System timer resolution is too low to handle Max
259 * Response Delay, so set 1 to the internal timer even if
260 * the calculated value equals to zero when Max Response
261 * Delay is positive.
262 */
263 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD_TIMER_SCALE;
264 if (timer == 0 && mldh->mld_maxdelay)
265 timer = 1;
266 mld6_all_nodes_linklocal.s6_addr16[1] =
267 htons(ifp->if_index); /* XXX */
268
269 IF_ADDR_LOCK(ifp);
270 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
271 if (ifma->ifma_addr->sa_family != AF_INET6)
272 continue;
273 in6m = (struct in6_multi *)ifma->ifma_protospec;
274
275 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
276 &mld6_all_nodes_linklocal) ||
277 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
278 IPV6_ADDR_SCOPE_LINKLOCAL)
279 continue;
280
281 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
282 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
283 &in6m->in6m_addr))
284 {
285 if (timer == 0) {
286 /* send a report immediately */
287 mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
288 NULL);
289 in6m->in6m_timer = 0; /* reset timer */
290 in6m->in6m_state = MLD_IREPORTEDLAST;
291 }
292 else if (in6m->in6m_timer == 0 || /*idle state*/
293 in6m->in6m_timer > timer) {
294 in6m->in6m_timer =
295 MLD_RANDOM_DELAY(timer);
296 mld6_timers_are_running = 1;
297 }
298 }
299 }
300 IF_ADDR_UNLOCK(ifp);
301
302 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
303 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
304 break;
305
306 case MLD_LISTENER_REPORT:
307 /*
308 * For fast leave to work, we have to know that we are the
309 * last person to send a report for this group. Reports
310 * can potentially get looped back if we are a multicast
311 * router, so discard reports sourced by me.
312 * Note that it is impossible to check IFF_LOOPBACK flag of
313 * ifp for this purpose, since ip6_mloopback pass the physical
314 * interface to looutput.
315 */
316 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
317 break;
318
319 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
320 break;
321
322 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
323 mldh->mld_addr.s6_addr16[1] =
324 htons(ifp->if_index); /* XXX */
325 /*
326 * If we belong to the group being reported, stop
327 * our timer for that group.
328 */
329 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m);
330 if (in6m) {
331 in6m->in6m_timer = 0; /* transit to idle state */
332 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */
333 }
334
335 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
336 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
337 break;
338 default: /* this is impossible */
339 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
340 break;
341 }
342
343 m_freem(m);
344 }
345
346 void
347 mld6_fasttimeo()
348 {
349 struct in6_multi *in6m;
350 struct in6_multistep step;
351 int s;
352
353 /*
354 * Quick check to see if any work needs to be done, in order
355 * to minimize the overhead of fasttimo processing.
356 */
357 if (!mld6_timers_are_running)
358 return;
359
360 s = splnet();
361
362 mld6_timers_are_running = 0;
363 IN6_FIRST_MULTI(step, in6m);
364 while (in6m != NULL) {
365 if (in6m->in6m_timer == 0) {
366 /* do nothing */
367 } else if (--in6m->in6m_timer == 0) {
368 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
369 in6m->in6m_state = MLD_IREPORTEDLAST;
370 } else {
371 mld6_timers_are_running = 1;
372 }
373 IN6_NEXT_MULTI(step, in6m);
374 }
375
376 splx(s);
377 }
378
379 static void
380 mld6_sendpkt(in6m, type, dst)
381 struct in6_multi *in6m;
382 int type;
383 const struct in6_addr *dst;
384 {
385 struct mbuf *mh, *md;
386 struct mld_hdr *mldh;
387 struct ip6_hdr *ip6;
388 struct ip6_moptions im6o;
389 struct in6_ifaddr *ia;
390 struct ifnet *ifp = in6m->in6m_ifp;
391 struct ifnet *outif = NULL;
392
393 /*
394 * At first, find a link local address on the outgoing interface
395 * to use as the source address of the MLD packet.
396 */
397 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
398 == NULL)
399 return;
400
401 /*
402 * Allocate mbufs to store ip6 header and MLD header.
403 * We allocate 2 mbufs and make chain in advance because
404 * it is more convenient when inserting the hop-by-hop option later.
405 */
406 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
407 if (mh == NULL)
408 return;
409 MGET(md, M_DONTWAIT, MT_DATA);
410 if (md == NULL) {
411 m_free(mh);
412 return;
413 }
414 mh->m_next = md;
415
416 mh->m_pkthdr.rcvif = NULL;
417 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
418 mh->m_len = sizeof(struct ip6_hdr);
419 MH_ALIGN(mh, sizeof(struct ip6_hdr));
420
421 /* fill in the ip6 header */
422 ip6 = mtod(mh, struct ip6_hdr *);
423 ip6->ip6_flow = 0;
424 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
425 ip6->ip6_vfc |= IPV6_VERSION;
426 /* ip6_plen will be set later */
427 ip6->ip6_nxt = IPPROTO_ICMPV6;
428 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
429 ip6->ip6_src = ia->ia_addr.sin6_addr;
430 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
431
432 /* fill in the MLD header */
433 md->m_len = sizeof(struct mld_hdr);
434 mldh = mtod(md, struct mld_hdr *);
435 mldh->mld_type = type;
436 mldh->mld_code = 0;
437 mldh->mld_cksum = 0;
438 /* XXX: we assume the function will not be called for query messages */
439 mldh->mld_maxdelay = 0;
440 mldh->mld_reserved = 0;
441 mldh->mld_addr = in6m->in6m_addr;
442 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
443 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
444 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
445 sizeof(struct mld_hdr));
446
447 /* construct multicast option */
448 bzero(&im6o, sizeof(im6o));
449 im6o.im6o_multicast_ifp = ifp;
450 im6o.im6o_multicast_hlim = 1;
451
452 /*
453 * Request loopback of the report if we are acting as a multicast
454 * router, so that the process-level routing daemon can hear it.
455 */
456 im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
457
458 /* increment output statictics */
459 icmp6stat.icp6s_outhist[type]++;
460
461 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL);
462 if (outif) {
463 icmp6_ifstat_inc(outif, ifs6_out_msg);
464 switch (type) {
465 case MLD_LISTENER_QUERY:
466 icmp6_ifstat_inc(outif, ifs6_out_mldquery);
467 break;
468 case MLD_LISTENER_REPORT:
469 icmp6_ifstat_inc(outif, ifs6_out_mldreport);
470 break;
471 case MLD_LISTENER_DONE:
472 icmp6_ifstat_inc(outif, ifs6_out_mlddone);
473 break;
474 }
475 }
476 }
477
478 /*
479 * Add an address to the list of IP6 multicast addresses for a given interface.
480 * Add source addresses to the list also, if upstream router is MLDv2 capable
481 * and the number of source is not 0.
482 */
483 struct in6_multi *
484 in6_addmulti(maddr6, ifp, errorp)
485 struct in6_addr *maddr6;
486 struct ifnet *ifp;
487 int *errorp;
488 {
489 struct in6_multi *in6m;
490 struct ifmultiaddr *ifma;
491 struct sockaddr_in6 sa6;
492 int s = splnet();
493
494 *errorp = 0;
495
496 /*
497 * Call generic routine to add membership or increment
498 * refcount. It wants addresses in the form of a sockaddr,
499 * so we build one here (being careful to zero the unused bytes).
500 */
501 bzero(&sa6, sizeof(sa6));
502 sa6.sin6_family = AF_INET6;
503 sa6.sin6_len = sizeof(struct sockaddr_in6);
504 sa6.sin6_addr = *maddr6;
505 *errorp = if_addmulti(ifp, (struct sockaddr *)&sa6, &ifma);
506 if (*errorp) {
507 splx(s);
508 return 0;
509 }
510
511 /*
512 * If ifma->ifma_protospec is null, then if_addmulti() created
513 * a new record. Otherwise, we are done.
514 */
515 if (ifma->ifma_protospec != 0) {
516 splx(s);
517 return ifma->ifma_protospec;
518 }
519
520 /* XXX - if_addmulti uses M_WAITOK. Can this really be called
521 at interrupt time? If so, need to fix if_addmulti. XXX */
522 in6m = (struct in6_multi *)malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT);
523 if (in6m == NULL) {
524 splx(s);
525 return (NULL);
526 }
527
528 bzero(in6m, sizeof *in6m);
529 in6m->in6m_addr = *maddr6;
530 in6m->in6m_ifp = ifp;
531 in6m->in6m_refcount = 1;
532 in6m->in6m_ifma = ifma;
533 ifma->ifma_protospec = in6m;
534 LIST_INSERT_HEAD(&in6_multihead, in6m, in6m_entry);
535
536 /*
537 * Let MLD6 know that we have joined a new IPv6 multicast
538 * group.
539 */
540 mld6_start_listening(in6m);
541 splx(s);
542 return (in6m);
543 }
544
545 /*
546 * Delete a multicast address record.
547 */
548 void
549 in6_delmulti(in6m)
550 struct in6_multi *in6m;
551 {
552 struct ifmultiaddr *ifma = in6m->in6m_ifma;
553 int s = splnet();
554
555 if (ifma->ifma_refcount == 1) {
556 /*
557 * No remaining claims to this record; let MLD6 know
558 * that we are leaving the multicast group.
559 */
560 mld6_stop_listening(in6m);
561 ifma->ifma_protospec = 0;
562 LIST_REMOVE(in6m, in6m_entry);
563 free(in6m, M_IPMADDR);
564 }
565 /* XXX - should be separate API for when we have an ifma? */
566 if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
567 splx(s);
568 }
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