1 /* $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.4 2003/01/23 21:06:47 sam 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 * 3. 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/malloc.h> /* for M_NOWAIT */
74 #include <sys/mbuf.h>
75 #include <sys/socket.h>
76 #include <sys/protosw.h>
77 #include <sys/syslog.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 MLD6_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 MLD6_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 static struct lwkt_token mld6_token = LWKT_TOKEN_INITIALIZER(mp_token);
111
112
113 void
mld6_init(void)114 mld6_init(void)
115 {
116 static u_int8_t hbh_buf[8];
117 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
118 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
119
120 mld6_timers_are_running = 0;
121
122 /* ip6h_nxt will be fill in later */
123 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */
124
125 /* XXX: grotty hard coding... */
126 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
127 hbh_buf[3] = 0;
128 hbh_buf[4] = IP6OPT_RTALERT;
129 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
130 bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
131
132 init_ip6pktopts(&ip6_opts);
133 ip6_opts.ip6po_hbh = hbh;
134 }
135
136 void
mld6_start_listening(struct in6_multi * in6m)137 mld6_start_listening(struct in6_multi *in6m)
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 lwkt_gettoken(&mld6_token);
147 mld6_all_nodes_linklocal.s6_addr16[1] =
148 htons(in6m->in6m_ifp->if_index); /* XXX */
149 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
150 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
151 in6m->in6m_timer = 0;
152 in6m->in6m_state = MLD6_OTHERLISTENER;
153 } else {
154 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
155 in6m->in6m_timer = MLD6_RANDOM_DELAY(
156 MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
157 in6m->in6m_state = MLD6_IREPORTEDLAST;
158 mld6_timers_are_running = 1;
159 }
160 lwkt_reltoken(&mld6_token);
161 }
162
163 void
mld6_stop_listening(struct in6_multi * in6m)164 mld6_stop_listening(struct in6_multi *in6m)
165 {
166 mld6_all_nodes_linklocal.s6_addr16[1] =
167 htons(in6m->in6m_ifp->if_index); /* XXX */
168 mld6_all_routers_linklocal.s6_addr16[1] =
169 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
170
171 if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
172 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
173 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL)
174 mld6_sendpkt(in6m, MLD_LISTENER_DONE,
175 &mld6_all_routers_linklocal);
176 }
177
178 void
mld6_input(struct mbuf * m,int off)179 mld6_input(struct mbuf *m, int off)
180 {
181 struct ip6_hdr *ip6;
182 struct mld_hdr *mldh;
183 struct ifnet *ifp = m->m_pkthdr.rcvif;
184 struct in6_multi *in6m;
185 struct in6_ifaddr *ia;
186 struct ifmultiaddr *ifma, mark;
187 struct sockaddr sa;
188 int timer; /* timer value in the MLD query header */
189
190 #ifndef PULLDOWN_TEST
191 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
192 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
193 #else
194 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
195 if (mldh == NULL) {
196 icmp6stat.icp6s_tooshort++;
197 return;
198 }
199 #endif
200
201 lwkt_gettoken(&mld6_token);
202 /* source address validation */
203 ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */
204 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
205 #if 0
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 #endif
211 /*
212 * spec (RFC2710) does not explicitly
213 * specify to discard the packet from a non link-local
214 * source address. But we believe it's expected to do so.
215 * XXX: do we have to allow :: as source?
216 */
217 m_freem(m);
218 lwkt_reltoken(&mld6_token);
219 return;
220 }
221
222 /*
223 * In the MLD6 specification, there are 3 states and a flag.
224 *
225 * In Non-Listener state, we simply don't have a membership record.
226 * In Delaying Listener state, our timer is running (in6m->in6m_timer)
227 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
228 *
229 * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
230 * we have heard a report from another member, or MLD6_IREPORTEDLAST
231 * if we sent the last report.
232 */
233 switch(mldh->mld_type) {
234 case MLD_LISTENER_QUERY:
235 if (ifp->if_flags & IFF_LOOPBACK)
236 break;
237
238 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
239 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
240 break; /* print error or log stat? */
241 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
242 mldh->mld_addr.s6_addr16[1] =
243 htons(ifp->if_index); /* XXX */
244
245 /*
246 * - Start the timers in all of our membership records
247 * that the query applies to for the interface on
248 * which the query arrived excl. those that belong
249 * to the "all-nodes" group (ff02::1).
250 * - Restart any timer that is already running but has
251 * A value longer than the requested timeout.
252 * - Use the value specified in the query message as
253 * the maximum timeout.
254 */
255 IFP_TO_IA6(ifp, ia);
256 if (ia == NULL)
257 break;
258
259 /*
260 * XXX: System timer resolution is too low to handle Max
261 * Response Delay, so set 1 to the internal timer even if
262 * the calculated value equals to zero when Max Response
263 * Delay is positive.
264 */
265 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ /
266 MLD6_TIMER_SCALE;
267 if (timer == 0 && mldh->mld_maxdelay)
268 timer = 1;
269 mld6_all_nodes_linklocal.s6_addr16[1] =
270 htons(ifp->if_index); /* XXX */
271
272 bzero(&sa, sizeof(sa));
273 sa.sa_family = AF_UNSPEC;
274 sa.sa_len = sizeof(sa);
275
276 bzero(&mark, sizeof(mark));
277 mark.ifma_addr = &sa;
278
279 /* TODO: need ifnet_serialize_main */
280 ifnet_serialize_all(ifp);
281
282 TAILQ_INSERT_HEAD(&ifp->if_multiaddrs, &mark, ifma_link);
283 while ((ifma = TAILQ_NEXT(&mark, ifma_link)) != NULL) {
284 TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link);
285 TAILQ_INSERT_AFTER(&ifp->if_multiaddrs, ifma, &mark,
286 ifma_link);
287
288 if (ifma->ifma_addr->sa_family != AF_INET6)
289 continue;
290 in6m = (struct in6_multi *)ifma->ifma_protospec;
291
292 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
293 &mld6_all_nodes_linklocal) ||
294 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
295 IPV6_ADDR_SCOPE_LINKLOCAL)
296 continue;
297
298 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
299 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
300 &in6m->in6m_addr))
301 {
302 if (timer == 0) {
303 /*
304 * Release serializer(s) temporarily,
305 * before sending report.
306 */
307 ifnet_deserialize_all(ifp);
308 /* send a report immediately */
309 mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
310 NULL);
311 ifnet_serialize_all(ifp);
312 in6m->in6m_timer = 0; /* reset timer */
313 in6m->in6m_state = MLD6_IREPORTEDLAST;
314 }
315 else if (in6m->in6m_timer == 0 || /*idle state*/
316 in6m->in6m_timer > timer) {
317 in6m->in6m_timer =
318 MLD6_RANDOM_DELAY(timer);
319 mld6_timers_are_running = 1;
320 }
321 }
322 }
323 TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link);
324
325 ifnet_deserialize_all(ifp);
326
327 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
328 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
329 break;
330
331 case MLD_LISTENER_REPORT:
332 /*
333 * For fast leave to work, we have to know that we are the
334 * last person to send a report for this group. Reports
335 * can potentially get looped back if we are a multicast
336 * router, so discard reports sourced by me.
337 * Note that it is impossible to check IFF_LOOPBACK flag of
338 * ifp for this purpose, since ip6_mloopback pass the physical
339 * interface to looutput.
340 */
341 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
342 break;
343
344 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
345 break;
346
347 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
348 mldh->mld_addr.s6_addr16[1] =
349 htons(ifp->if_index); /* XXX */
350 /*
351 * If we belong to the group being reported, stop
352 * our timer for that group.
353 */
354 in6m = IN6_LOOKUP_MULTI(&mldh->mld_addr, ifp);
355 if (in6m) {
356 in6m->in6m_timer = 0; /* transit to idle state */
357 in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
358 }
359
360 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
361 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
362 break;
363 default: /* this is impossible */
364 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
365 break;
366 }
367
368 m_freem(m);
369 lwkt_reltoken(&mld6_token);
370 }
371
372 void
mld6_fasttimeo(void)373 mld6_fasttimeo(void)
374 {
375 struct in6_multi *in6m;
376 struct in6_multistep step;
377
378 /*
379 * Quick check to see if any work needs to be done, in order
380 * to minimize the overhead of fasttimo processing.
381 */
382 lwkt_gettoken(&mld6_token);
383
384 if (!mld6_timers_are_running) {
385 lwkt_reltoken(&mld6_token);
386 return;
387 }
388
389 mld6_timers_are_running = 0;
390 IN6_FIRST_MULTI(step, in6m);
391 while (in6m != NULL) {
392 if (in6m->in6m_timer == 0) {
393 /* do nothing */
394 } else if (--in6m->in6m_timer == 0) {
395 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
396 in6m->in6m_state = MLD6_IREPORTEDLAST;
397 } else {
398 mld6_timers_are_running = 1;
399 }
400 IN6_NEXT_MULTI(step, in6m);
401 }
402
403 lwkt_reltoken(&mld6_token);
404 }
405
406 static void
mld6_sendpkt(struct in6_multi * in6m,int type,const struct in6_addr * dst)407 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
408 {
409 struct mbuf *mh, *md;
410 struct mld_hdr *mldh;
411 struct ip6_hdr *ip6;
412 struct ip6_moptions im6o;
413 struct in6_ifaddr *ia;
414 struct ifnet *ifp = in6m->in6m_ifp;
415 struct ifnet *outif = NULL;
416
417 /*
418 * At first, find a link local address on the outgoing interface
419 * to use as the source address of the MLD packet.
420 */
421 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
422 == NULL)
423 return;
424
425 /*
426 * Allocate mbufs to store ip6 header and MLD header.
427 * We allocate 2 mbufs and make chain in advance because
428 * it is more convenient when inserting the hop-by-hop option later.
429 */
430 MGETHDR(mh, M_NOWAIT, MT_HEADER);
431 if (mh == NULL)
432 return;
433 MGET(md, M_NOWAIT, MT_DATA);
434 if (md == NULL) {
435 m_free(mh);
436 return;
437 }
438 mh->m_next = md;
439
440 mh->m_pkthdr.rcvif = NULL;
441 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
442 mh->m_len = sizeof(struct ip6_hdr);
443 MH_ALIGN(mh, sizeof(struct ip6_hdr));
444
445 /* fill in the ip6 header */
446 ip6 = mtod(mh, struct ip6_hdr *);
447 ip6->ip6_flow = 0;
448 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
449 ip6->ip6_vfc |= IPV6_VERSION;
450 /* ip6_plen will be set later */
451 ip6->ip6_nxt = IPPROTO_ICMPV6;
452 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
453 ip6->ip6_src = ia->ia_addr.sin6_addr;
454 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
455
456 /* fill in the MLD header */
457 md->m_len = sizeof(struct mld_hdr);
458 mldh = mtod(md, struct mld_hdr *);
459 mldh->mld_type = type;
460 mldh->mld_code = 0;
461 mldh->mld_cksum = 0;
462 /* XXX: we assume the function will not be called for query messages */
463 mldh->mld_maxdelay = 0;
464 mldh->mld_reserved = 0;
465 mldh->mld_addr = in6m->in6m_addr;
466 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
467 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
468 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
469 sizeof(struct mld_hdr));
470
471 /* construct multicast option */
472 bzero(&im6o, sizeof(im6o));
473 im6o.im6o_multicast_ifp = ifp;
474 im6o.im6o_multicast_hlim = 1;
475
476 /*
477 * Request loopback of the report if we are acting as a multicast
478 * router, so that the process-level routing daemon can hear it.
479 */
480 im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
481
482 /* increment output statictics */
483 icmp6stat.icp6s_outhist[type]++;
484
485 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL);
486 if (outif) {
487 icmp6_ifstat_inc(outif, ifs6_out_msg);
488 switch (type) {
489 case MLD_LISTENER_QUERY:
490 icmp6_ifstat_inc(outif, ifs6_out_mldquery);
491 break;
492 case MLD_LISTENER_REPORT:
493 icmp6_ifstat_inc(outif, ifs6_out_mldreport);
494 break;
495 case MLD_LISTENER_DONE:
496 icmp6_ifstat_inc(outif, ifs6_out_mlddone);
497 break;
498 }
499 }
500 }
501