FreeBSD/Linux Kernel Cross Reference
sys/netinet6/mld6.c
1 /* $FreeBSD: releng/5.2/sys/netinet6/mld6.c 121808 2003-10-31 16:07:15Z ume $ */
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. All advertising materials mentioning features or use of this software
50 * must display the following acknowledgement:
51 * This product includes software developed by the University of
52 * California, Berkeley and its contributors.
53 * 4. Neither the name of the University nor the names of its contributors
54 * may be used to endorse or promote products derived from this software
55 * without specific prior written permission.
56 *
57 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
58 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
61 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67 * SUCH DAMAGE.
68 *
69 * @(#)igmp.c 8.1 (Berkeley) 7/19/93
70 */
71
72 #include "opt_inet.h"
73 #include "opt_inet6.h"
74
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/mbuf.h>
78 #include <sys/socket.h>
79 #include <sys/protosw.h>
80 #include <sys/syslog.h>
81
82 #include <net/if.h>
83
84 #include <netinet/in.h>
85 #include <netinet/in_var.h>
86 #include <netinet/ip6.h>
87 #include <netinet6/ip6_var.h>
88 #include <netinet/icmp6.h>
89 #include <netinet6/mld6_var.h>
90
91 #include <net/net_osdep.h>
92
93 /*
94 * Protocol constants
95 */
96
97 /* denotes that the MLD max response delay field specifies time in milliseconds */
98 #define MLD_TIMER_SCALE 1000
99 /*
100 * time between repetitions of a node's initial report of interest in a
101 * multicast address(in seconds)
102 */
103 #define MLD_UNSOLICITED_REPORT_INTERVAL 10
104
105 static struct ip6_pktopts ip6_opts;
106 static int mld6_timers_are_running;
107 /* XXX: These are necessary for KAME's link-local hack */
108 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
109 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
110
111 static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
112
113 void
114 mld6_init()
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_ROUTER_ALERT;
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
137 mld6_start_listening(in6m)
138 struct in6_multi *in6m;
139 {
140 int s = splnet();
141
142 /*
143 * RFC2710 page 10:
144 * The node never sends a Report or Done for the link-scope all-nodes
145 * address.
146 * MLD messages are never sent for multicast addresses whose scope is 0
147 * (reserved) or 1 (node-local).
148 */
149 mld6_all_nodes_linklocal.s6_addr16[1] =
150 htons(in6m->in6m_ifp->if_index); /* XXX */
151 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
152 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
153 in6m->in6m_timer = 0;
154 in6m->in6m_state = MLD_OTHERLISTENER;
155 } else {
156 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
157 in6m->in6m_timer =
158 MLD_RANDOM_DELAY(MLD_UNSOLICITED_REPORT_INTERVAL *
159 PR_FASTHZ);
160 in6m->in6m_state = MLD_IREPORTEDLAST;
161 mld6_timers_are_running = 1;
162 }
163 splx(s);
164 }
165
166 void
167 mld6_stop_listening(in6m)
168 struct in6_multi *in6m;
169 {
170 mld6_all_nodes_linklocal.s6_addr16[1] =
171 htons(in6m->in6m_ifp->if_index); /* XXX */
172 mld6_all_routers_linklocal.s6_addr16[1] =
173 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
174
175 if (in6m->in6m_state == MLD_IREPORTEDLAST &&
176 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
177 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_INTFACELOCAL)
178 mld6_sendpkt(in6m, MLD_LISTENER_DONE,
179 &mld6_all_routers_linklocal);
180 }
181
182 void
183 mld6_input(m, off)
184 struct mbuf *m;
185 int off;
186 {
187 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
188 struct mld_hdr *mldh;
189 struct ifnet *ifp = m->m_pkthdr.rcvif;
190 struct in6_multi *in6m;
191 struct in6_ifaddr *ia;
192 struct ifmultiaddr *ifma;
193 int timer; /* timer value in the MLD query header */
194
195 #ifndef PULLDOWN_TEST
196 IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
197 mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
198 #else
199 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
200 if (mldh == NULL) {
201 icmp6stat.icp6s_tooshort++;
202 return;
203 }
204 #endif
205
206 /* source address validation */
207 ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */
208 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
209 log(LOG_ERR,
210 "mld6_input: src %s is not link-local (grp=%s)\n",
211 ip6_sprintf(&ip6->ip6_src),
212 ip6_sprintf(&mldh->mld_addr));
213 /*
214 * spec (RFC2710) does not explicitly
215 * specify to discard the packet from a non link-local
216 * source address. But we believe it's expected to do so.
217 * XXX: do we have to allow :: as source?
218 */
219 m_freem(m);
220 return;
221 }
222
223 /*
224 * In the MLD6 specification, there are 3 states and a flag.
225 *
226 * In Non-Listener state, we simply don't have a membership record.
227 * In Delaying Listener state, our timer is running (in6m->in6m_timer)
228 * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
229 *
230 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if
231 * we have heard a report from another member, or MLD_IREPORTEDLAST
232 * if we sent the last report.
233 */
234 switch(mldh->mld_type) {
235 case MLD_LISTENER_QUERY:
236 if (ifp->if_flags & IFF_LOOPBACK)
237 break;
238
239 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
240 !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
241 break; /* print error or log stat? */
242 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
243 mldh->mld_addr.s6_addr16[1] =
244 htons(ifp->if_index); /* XXX */
245
246 /*
247 * - Start the timers in all of our membership records
248 * that the query applies to for the interface on
249 * which the query arrived excl. those that belong
250 * to the "all-nodes" group (ff02::1).
251 * - Restart any timer that is already running but has
252 * A value longer than the requested timeout.
253 * - Use the value specified in the query message as
254 * the maximum timeout.
255 */
256 IFP_TO_IA6(ifp, ia);
257 if (ia == NULL)
258 break;
259
260 /*
261 * XXX: System timer resolution is too low to handle Max
262 * Response Delay, so set 1 to the internal timer even if
263 * the calculated value equals to zero when Max Response
264 * Delay is positive.
265 */
266 timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD_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 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
273 if (ifma->ifma_addr->sa_family != AF_INET6)
274 continue;
275 in6m = (struct in6_multi *)ifma->ifma_protospec;
276
277 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
278 &mld6_all_nodes_linklocal) ||
279 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
280 IPV6_ADDR_SCOPE_LINKLOCAL)
281 continue;
282
283 if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
284 IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
285 &in6m->in6m_addr))
286 {
287 if (timer == 0) {
288 /* send a report immediately */
289 mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
290 NULL);
291 in6m->in6m_timer = 0; /* reset timer */
292 in6m->in6m_state = MLD_IREPORTEDLAST;
293 }
294 else if (in6m->in6m_timer == 0 || /*idle state*/
295 in6m->in6m_timer > timer) {
296 in6m->in6m_timer =
297 MLD_RANDOM_DELAY(timer);
298 mld6_timers_are_running = 1;
299 }
300 }
301 }
302
303 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
304 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
305 break;
306
307 case MLD_LISTENER_REPORT:
308 /*
309 * For fast leave to work, we have to know that we are the
310 * last person to send a report for this group. Reports
311 * can potentially get looped back if we are a multicast
312 * router, so discard reports sourced by me.
313 * Note that it is impossible to check IFF_LOOPBACK flag of
314 * ifp for this purpose, since ip6_mloopback pass the physical
315 * interface to looutput.
316 */
317 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
318 break;
319
320 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
321 break;
322
323 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
324 mldh->mld_addr.s6_addr16[1] =
325 htons(ifp->if_index); /* XXX */
326 /*
327 * If we belong to the group being reported, stop
328 * our timer for that group.
329 */
330 IN6_LOOKUP_MULTI(mldh->mld_addr, ifp, in6m);
331 if (in6m) {
332 in6m->in6m_timer = 0; /* transit to idle state */
333 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */
334 }
335
336 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
337 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
338 break;
339 default: /* this is impossible */
340 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
341 break;
342 }
343
344 m_freem(m);
345 }
346
347 void
348 mld6_fasttimeo()
349 {
350 struct in6_multi *in6m;
351 struct in6_multistep step;
352 int s;
353
354 /*
355 * Quick check to see if any work needs to be done, in order
356 * to minimize the overhead of fasttimo processing.
357 */
358 if (!mld6_timers_are_running)
359 return;
360
361 s = splnet();
362
363 mld6_timers_are_running = 0;
364 IN6_FIRST_MULTI(step, in6m);
365 while (in6m != NULL) {
366 if (in6m->in6m_timer == 0) {
367 /* do nothing */
368 } else if (--in6m->in6m_timer == 0) {
369 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
370 in6m->in6m_state = MLD_IREPORTEDLAST;
371 } else {
372 mld6_timers_are_running = 1;
373 }
374 IN6_NEXT_MULTI(step, in6m);
375 }
376
377 splx(s);
378 }
379
380 static void
381 mld6_sendpkt(in6m, type, dst)
382 struct in6_multi *in6m;
383 int type;
384 const struct in6_addr *dst;
385 {
386 struct mbuf *mh, *md;
387 struct mld_hdr *mldh;
388 struct ip6_hdr *ip6;
389 struct ip6_moptions im6o;
390 struct in6_ifaddr *ia;
391 struct ifnet *ifp = in6m->in6m_ifp;
392 struct ifnet *outif = NULL;
393
394 /*
395 * At first, find a link local address on the outgoing interface
396 * to use as the source address of the MLD packet.
397 */
398 if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
399 == NULL)
400 return;
401
402 /*
403 * Allocate mbufs to store ip6 header and MLD header.
404 * We allocate 2 mbufs and make chain in advance because
405 * it is more convenient when inserting the hop-by-hop option later.
406 */
407 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
408 if (mh == NULL)
409 return;
410 MGET(md, M_DONTWAIT, MT_DATA);
411 if (md == NULL) {
412 m_free(mh);
413 return;
414 }
415 mh->m_next = md;
416
417 mh->m_pkthdr.rcvif = NULL;
418 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
419 mh->m_len = sizeof(struct ip6_hdr);
420 MH_ALIGN(mh, sizeof(struct ip6_hdr));
421
422 /* fill in the ip6 header */
423 ip6 = mtod(mh, struct ip6_hdr *);
424 ip6->ip6_flow = 0;
425 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
426 ip6->ip6_vfc |= IPV6_VERSION;
427 /* ip6_plen will be set later */
428 ip6->ip6_nxt = IPPROTO_ICMPV6;
429 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
430 ip6->ip6_src = ia->ia_addr.sin6_addr;
431 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
432
433 /* fill in the MLD header */
434 md->m_len = sizeof(struct mld_hdr);
435 mldh = mtod(md, struct mld_hdr *);
436 mldh->mld_type = type;
437 mldh->mld_code = 0;
438 mldh->mld_cksum = 0;
439 /* XXX: we assume the function will not be called for query messages */
440 mldh->mld_maxdelay = 0;
441 mldh->mld_reserved = 0;
442 mldh->mld_addr = in6m->in6m_addr;
443 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
444 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
445 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
446 sizeof(struct mld_hdr));
447
448 /* construct multicast option */
449 bzero(&im6o, sizeof(im6o));
450 im6o.im6o_multicast_ifp = ifp;
451 im6o.im6o_multicast_hlim = 1;
452
453 /*
454 * Request loopback of the report if we are acting as a multicast
455 * router, so that the process-level routing daemon can hear it.
456 */
457 im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
458
459 /* increment output statictics */
460 icmp6stat.icp6s_outhist[type]++;
461
462 ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL);
463 if (outif) {
464 icmp6_ifstat_inc(outif, ifs6_out_msg);
465 switch (type) {
466 case MLD_LISTENER_QUERY:
467 icmp6_ifstat_inc(outif, ifs6_out_mldquery);
468 break;
469 case MLD_LISTENER_REPORT:
470 icmp6_ifstat_inc(outif, ifs6_out_mldreport);
471 break;
472 case MLD_LISTENER_DONE:
473 icmp6_ifstat_inc(outif, ifs6_out_mlddone);
474 break;
475 }
476 }
477 }
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