FreeBSD/Linux Kernel Cross Reference
sys/netinet6/mld6.c
1 /* $NetBSD: mld6.c,v 1.47 2008/08/22 17:11:39 adrianp Exp $ */
2 /* $KAME: mld6.c,v 1.25 2001/01/16 14:14:18 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) 1992, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * This code is derived from software contributed to Berkeley by
38 * Stephen Deering of Stanford University.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 * 3. Neither the name of the University nor the names of its contributors
49 * may be used to endorse or promote products derived from this software
50 * without specific prior written permission.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62 * SUCH DAMAGE.
63 *
64 * @(#)igmp.c 8.1 (Berkeley) 7/19/93
65 */
66
67 /*
68 * Copyright (c) 1988 Stephen Deering.
69 *
70 * This code is derived from software contributed to Berkeley by
71 * Stephen Deering of Stanford University.
72 *
73 * Redistribution and use in source and binary forms, with or without
74 * modification, are permitted provided that the following conditions
75 * are met:
76 * 1. Redistributions of source code must retain the above copyright
77 * notice, this list of conditions and the following disclaimer.
78 * 2. Redistributions in binary form must reproduce the above copyright
79 * notice, this list of conditions and the following disclaimer in the
80 * documentation and/or other materials provided with the distribution.
81 * 3. All advertising materials mentioning features or use of this software
82 * must display the following acknowledgement:
83 * This product includes software developed by the University of
84 * California, Berkeley and its contributors.
85 * 4. Neither the name of the University nor the names of its contributors
86 * may be used to endorse or promote products derived from this software
87 * without specific prior written permission.
88 *
89 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
90 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
91 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
92 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
93 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
94 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
95 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
96 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
97 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
98 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99 * SUCH DAMAGE.
100 *
101 * @(#)igmp.c 8.1 (Berkeley) 7/19/93
102 */
103
104 #include <sys/cdefs.h>
105 __KERNEL_RCSID(0, "$NetBSD: mld6.c,v 1.47 2008/08/22 17:11:39 adrianp Exp $");
106
107 #include "opt_inet.h"
108
109 #include <sys/param.h>
110 #include <sys/systm.h>
111 #include <sys/mbuf.h>
112 #include <sys/socket.h>
113 #include <sys/socketvar.h>
114 #include <sys/protosw.h>
115 #include <sys/syslog.h>
116 #include <sys/sysctl.h>
117 #include <sys/kernel.h>
118 #include <sys/callout.h>
119
120 #include <net/if.h>
121
122 #include <netinet/in.h>
123 #include <netinet/in_var.h>
124 #include <netinet6/in6_var.h>
125 #include <netinet/ip6.h>
126 #include <netinet6/ip6_var.h>
127 #include <netinet6/scope6_var.h>
128 #include <netinet/icmp6.h>
129 #include <netinet6/icmp6_private.h>
130 #include <netinet6/mld6_var.h>
131
132 #include <net/net_osdep.h>
133
134
135 /*
136 * This structure is used to keep track of in6_multi chains which belong to
137 * deleted interface addresses.
138 */
139 static LIST_HEAD(, multi6_kludge) in6_mk; /* XXX BSS initialization */
140
141 struct multi6_kludge {
142 LIST_ENTRY(multi6_kludge) mk_entry;
143 struct ifnet *mk_ifp;
144 struct in6_multihead mk_head;
145 };
146
147
148 /*
149 * Protocol constants
150 */
151
152 /*
153 * time between repetitions of a node's initial report of interest in a
154 * multicast address(in seconds)
155 */
156 #define MLD_UNSOLICITED_REPORT_INTERVAL 10
157
158 static struct ip6_pktopts ip6_opts;
159
160 static void mld_start_listening(struct in6_multi *);
161 static void mld_stop_listening(struct in6_multi *);
162
163 static struct mld_hdr * mld_allocbuf(struct mbuf **, int, struct in6_multi *,
164 int);
165 static void mld_sendpkt(struct in6_multi *, int, const struct in6_addr *);
166 static void mld_starttimer(struct in6_multi *);
167 static void mld_stoptimer(struct in6_multi *);
168 static u_long mld_timerresid(struct in6_multi *);
169
170 void
171 mld_init(void)
172 {
173 static u_int8_t hbh_buf[8];
174 struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
175 u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
176
177 /* ip6h_nxt will be fill in later */
178 hbh->ip6h_len = 0; /* (8 >> 3) - 1 */
179
180 /* XXX: grotty hard coding... */
181 hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
182 hbh_buf[3] = 0;
183 hbh_buf[4] = IP6OPT_RTALERT;
184 hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
185 bcopy((void *)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
186
187 ip6_opts.ip6po_hbh = hbh;
188 /* We will specify the hoplimit by a multicast option. */
189 ip6_opts.ip6po_hlim = -1;
190 }
191
192 static void
193 mld_starttimer(struct in6_multi *in6m)
194 {
195 struct timeval now;
196
197 microtime(&now);
198 in6m->in6m_timer_expire.tv_sec = now.tv_sec + in6m->in6m_timer / hz;
199 in6m->in6m_timer_expire.tv_usec = now.tv_usec +
200 (in6m->in6m_timer % hz) * (1000000 / hz);
201 if (in6m->in6m_timer_expire.tv_usec > 1000000) {
202 in6m->in6m_timer_expire.tv_sec++;
203 in6m->in6m_timer_expire.tv_usec -= 1000000;
204 }
205
206 /* start or restart the timer */
207 callout_schedule(&in6m->in6m_timer_ch, in6m->in6m_timer);
208 }
209
210 static void
211 mld_stoptimer(struct in6_multi *in6m)
212 {
213 if (in6m->in6m_timer == IN6M_TIMER_UNDEF)
214 return;
215
216 callout_stop(&in6m->in6m_timer_ch);
217
218 in6m->in6m_timer = IN6M_TIMER_UNDEF;
219 }
220
221 static void
222 mld_timeo(void *arg)
223 {
224 struct in6_multi *in6m = arg;
225
226 mutex_enter(softnet_lock);
227 KERNEL_LOCK(1, NULL);
228
229 in6m->in6m_timer = IN6M_TIMER_UNDEF;
230
231 switch (in6m->in6m_state) {
232 case MLD_REPORTPENDING:
233 mld_start_listening(in6m);
234 break;
235 default:
236 mld_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
237 break;
238 }
239
240 KERNEL_UNLOCK_ONE(NULL);
241 mutex_exit(softnet_lock);
242 }
243
244 static u_long
245 mld_timerresid(struct in6_multi *in6m)
246 {
247 struct timeval now, diff;
248
249 microtime(&now);
250
251 if (now.tv_sec > in6m->in6m_timer_expire.tv_sec ||
252 (now.tv_sec == in6m->in6m_timer_expire.tv_sec &&
253 now.tv_usec > in6m->in6m_timer_expire.tv_usec)) {
254 return (0);
255 }
256 diff = in6m->in6m_timer_expire;
257 diff.tv_sec -= now.tv_sec;
258 diff.tv_usec -= now.tv_usec;
259 if (diff.tv_usec < 0) {
260 diff.tv_sec--;
261 diff.tv_usec += 1000000;
262 }
263
264 /* return the remaining time in milliseconds */
265 return diff.tv_sec * 1000 + diff.tv_usec / 1000;
266 }
267
268 static void
269 mld_start_listening(struct in6_multi *in6m)
270 {
271 struct in6_addr all_in6;
272
273 /*
274 * RFC2710 page 10:
275 * The node never sends a Report or Done for the link-scope all-nodes
276 * address.
277 * MLD messages are never sent for multicast addresses whose scope is 0
278 * (reserved) or 1 (node-local).
279 */
280 all_in6 = in6addr_linklocal_allnodes;
281 if (in6_setscope(&all_in6, in6m->in6m_ifp, NULL)) {
282 /* XXX: this should not happen! */
283 in6m->in6m_timer = 0;
284 in6m->in6m_state = MLD_OTHERLISTENER;
285 }
286 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) ||
287 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
288 in6m->in6m_timer = IN6M_TIMER_UNDEF;
289 in6m->in6m_state = MLD_OTHERLISTENER;
290 } else {
291 mld_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
292 in6m->in6m_timer = arc4random() %
293 (MLD_UNSOLICITED_REPORT_INTERVAL * hz);
294 in6m->in6m_state = MLD_IREPORTEDLAST;
295
296 mld_starttimer(in6m);
297 }
298 }
299
300 static void
301 mld_stop_listening(struct in6_multi *in6m)
302 {
303 struct in6_addr allnode, allrouter;
304
305 allnode = in6addr_linklocal_allnodes;
306 if (in6_setscope(&allnode, in6m->in6m_ifp, NULL)) {
307 /* XXX: this should not happen! */
308 return;
309 }
310 allrouter = in6addr_linklocal_allrouters;
311 if (in6_setscope(&allrouter, in6m->in6m_ifp, NULL)) {
312 /* XXX impossible */
313 return;
314 }
315
316 if (in6m->in6m_state == MLD_IREPORTEDLAST &&
317 (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &allnode)) &&
318 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) >
319 IPV6_ADDR_SCOPE_INTFACELOCAL) {
320 mld_sendpkt(in6m, MLD_LISTENER_DONE, &allrouter);
321 }
322 }
323
324 void
325 mld_input(struct mbuf *m, int off)
326 {
327 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
328 struct mld_hdr *mldh;
329 struct ifnet *ifp = m->m_pkthdr.rcvif;
330 struct in6_multi *in6m = NULL;
331 struct in6_addr mld_addr, all_in6;
332 struct in6_ifaddr *ia;
333 u_long timer = 0; /* timer value in the MLD query header */
334
335 IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
336 if (mldh == NULL) {
337 ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
338 return;
339 }
340
341 /* source address validation */
342 ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
343 if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
344 /*
345 * RFC3590 allows the IPv6 unspecified address as the source
346 * address of MLD report and done messages. However, as this
347 * same document says, this special rule is for snooping
348 * switches and the RFC requires routers to discard MLD packets
349 * with the unspecified source address. The RFC only talks
350 * about hosts receiving an MLD query or report in Security
351 * Considerations, but this is probably the correct intention.
352 * RFC3590 does not talk about other cases than link-local and
353 * the unspecified source addresses, but we believe the same
354 * rule should be applied.
355 * As a result, we only allow link-local addresses as the
356 * source address; otherwise, simply discard the packet.
357 */
358 #if 0
359 /*
360 * XXX: do not log in an input path to avoid log flooding,
361 * though RFC3590 says "SHOULD log" if the source of a query
362 * is the unspecified address.
363 */
364 log(LOG_INFO,
365 "mld_input: src %s is not link-local (grp=%s)\n",
366 ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&mldh->mld_addr));
367 #endif
368 m_freem(m);
369 return;
370 }
371
372 /*
373 * make a copy for local work (in6_setscope() may modify the 1st arg)
374 */
375 mld_addr = mldh->mld_addr;
376 if (in6_setscope(&mld_addr, ifp, NULL)) {
377 /* XXX: this should not happen! */
378 m_free(m);
379 return;
380 }
381
382 /*
383 * In the MLD specification, there are 3 states and a flag.
384 *
385 * In Non-Listener state, we simply don't have a membership record.
386 * In Delaying Listener state, our timer is running (in6m->in6m_timer)
387 * In Idle Listener state, our timer is not running
388 * (in6m->in6m_timer==IN6M_TIMER_UNDEF)
389 *
390 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if
391 * we have heard a report from another member, or MLD_IREPORTEDLAST
392 * if we sent the last report.
393 */
394 switch (mldh->mld_type) {
395 case MLD_LISTENER_QUERY:
396 if (ifp->if_flags & IFF_LOOPBACK)
397 break;
398
399 if (!IN6_IS_ADDR_UNSPECIFIED(&mld_addr) &&
400 !IN6_IS_ADDR_MULTICAST(&mld_addr))
401 break; /* print error or log stat? */
402
403 all_in6 = in6addr_linklocal_allnodes;
404 if (in6_setscope(&all_in6, ifp, NULL)) {
405 /* XXX: this should not happen! */
406 break;
407 }
408
409 /*
410 * - Start the timers in all of our membership records
411 * that the query applies to for the interface on
412 * which the query arrived excl. those that belong
413 * to the "all-nodes" group (ff02::1).
414 * - Restart any timer that is already running but has
415 * a value longer than the requested timeout.
416 * - Use the value specified in the query message as
417 * the maximum timeout.
418 */
419 timer = ntohs(mldh->mld_maxdelay);
420
421 IFP_TO_IA6(ifp, ia);
422 if (ia == NULL)
423 break;
424
425 LIST_FOREACH(in6m, &ia->ia6_multiaddrs, in6m_entry) {
426 if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) ||
427 IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
428 IPV6_ADDR_SCOPE_LINKLOCAL)
429 continue;
430
431 if (in6m->in6m_state == MLD_REPORTPENDING)
432 continue; /* we are not yet ready */
433
434 if (!IN6_IS_ADDR_UNSPECIFIED(&mld_addr) &&
435 !IN6_ARE_ADDR_EQUAL(&mld_addr, &in6m->in6m_addr))
436 continue;
437
438 if (timer == 0) {
439 /* send a report immediately */
440 mld_stoptimer(in6m);
441 mld_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
442 in6m->in6m_state = MLD_IREPORTEDLAST;
443 } else if (in6m->in6m_timer == IN6M_TIMER_UNDEF ||
444 mld_timerresid(in6m) > timer) {
445 in6m->in6m_timer =
446 1 + (arc4random() % timer) * hz / 1000;
447 mld_starttimer(in6m);
448 }
449 }
450 break;
451
452 case MLD_LISTENER_REPORT:
453 /*
454 * For fast leave to work, we have to know that we are the
455 * last person to send a report for this group. Reports
456 * can potentially get looped back if we are a multicast
457 * router, so discard reports sourced by me.
458 * Note that it is impossible to check IFF_LOOPBACK flag of
459 * ifp for this purpose, since ip6_mloopback pass the physical
460 * interface to looutput.
461 */
462 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
463 break;
464
465 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
466 break;
467
468 /*
469 * If we belong to the group being reported, stop
470 * our timer for that group.
471 */
472 IN6_LOOKUP_MULTI(mld_addr, ifp, in6m);
473 if (in6m) {
474 mld_stoptimer(in6m); /* transit to idle state */
475 in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */
476 }
477 break;
478 default: /* this is impossible */
479 #if 0
480 /*
481 * this case should be impossible because of filtering in
482 * icmp6_input(). But we explicitly disabled this part
483 * just in case.
484 */
485 log(LOG_ERR, "mld_input: illegal type(%d)", mldh->mld_type);
486 #endif
487 break;
488 }
489
490 m_freem(m);
491 }
492
493 static void
494 mld_sendpkt(struct in6_multi *in6m, int type,
495 const struct in6_addr *dst)
496 {
497 struct mbuf *mh;
498 struct mld_hdr *mldh;
499 struct ip6_hdr *ip6 = NULL;
500 struct ip6_moptions im6o;
501 struct in6_ifaddr *ia = NULL;
502 struct ifnet *ifp = in6m->in6m_ifp;
503 int ignflags;
504
505 /*
506 * At first, find a link local address on the outgoing interface
507 * to use as the source address of the MLD packet.
508 * We do not reject tentative addresses for MLD report to deal with
509 * the case where we first join a link-local address.
510 */
511 ignflags = (IN6_IFF_NOTREADY|IN6_IFF_ANYCAST) & ~IN6_IFF_TENTATIVE;
512 if ((ia = in6ifa_ifpforlinklocal(ifp, ignflags)) == NULL)
513 return;
514 if ((ia->ia6_flags & IN6_IFF_TENTATIVE))
515 ia = NULL;
516
517 /* Allocate two mbufs to store IPv6 header and MLD header */
518 mldh = mld_allocbuf(&mh, sizeof(struct mld_hdr), in6m, type);
519 if (mldh == NULL)
520 return;
521
522 /* fill src/dst here */
523 ip6 = mtod(mh, struct ip6_hdr *);
524 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
525 ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
526
527 mldh->mld_addr = in6m->in6m_addr;
528 in6_clearscope(&mldh->mld_addr); /* XXX */
529 mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
530 sizeof(struct mld_hdr));
531
532 /* construct multicast option */
533 memset(&im6o, 0, sizeof(im6o));
534 im6o.im6o_multicast_ifp = ifp;
535 im6o.im6o_multicast_hlim = 1;
536
537 /*
538 * Request loopback of the report if we are acting as a multicast
539 * router, so that the process-level routing daemon can hear it.
540 */
541 im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
542
543 /* increment output statictics */
544 ICMP6_STATINC(ICMP6_STAT_OUTHIST + type);
545 icmp6_ifstat_inc(ifp, ifs6_out_msg);
546 switch (type) {
547 case MLD_LISTENER_QUERY:
548 icmp6_ifstat_inc(ifp, ifs6_out_mldquery);
549 break;
550 case MLD_LISTENER_REPORT:
551 icmp6_ifstat_inc(ifp, ifs6_out_mldreport);
552 break;
553 case MLD_LISTENER_DONE:
554 icmp6_ifstat_inc(ifp, ifs6_out_mlddone);
555 break;
556 }
557
558 ip6_output(mh, &ip6_opts, NULL, ia ? 0 : IPV6_UNSPECSRC,
559 &im6o, (struct socket *)NULL, NULL);
560 }
561
562 static struct mld_hdr *
563 mld_allocbuf(struct mbuf **mh, int len, struct in6_multi *in6m,
564 int type)
565 {
566 struct mbuf *md;
567 struct mld_hdr *mldh;
568 struct ip6_hdr *ip6;
569
570 /*
571 * Allocate mbufs to store ip6 header and MLD header.
572 * We allocate 2 mbufs and make chain in advance because
573 * it is more convenient when inserting the hop-by-hop option later.
574 */
575 MGETHDR(*mh, M_DONTWAIT, MT_HEADER);
576 if (*mh == NULL)
577 return NULL;
578 MGET(md, M_DONTWAIT, MT_DATA);
579 if (md == NULL) {
580 m_free(*mh);
581 *mh = NULL;
582 return NULL;
583 }
584 (*mh)->m_next = md;
585 md->m_next = NULL;
586
587 (*mh)->m_pkthdr.rcvif = NULL;
588 (*mh)->m_pkthdr.len = sizeof(struct ip6_hdr) + len;
589 (*mh)->m_len = sizeof(struct ip6_hdr);
590 MH_ALIGN(*mh, sizeof(struct ip6_hdr));
591
592 /* fill in the ip6 header */
593 ip6 = mtod(*mh, struct ip6_hdr *);
594 memset(ip6, 0, sizeof(*ip6));
595 ip6->ip6_flow = 0;
596 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
597 ip6->ip6_vfc |= IPV6_VERSION;
598 /* ip6_plen will be set later */
599 ip6->ip6_nxt = IPPROTO_ICMPV6;
600 /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
601 /* ip6_src/dst will be set by mld_sendpkt() or mld_sendbuf() */
602
603 /* fill in the MLD header as much as possible */
604 md->m_len = len;
605 mldh = mtod(md, struct mld_hdr *);
606 memset(mldh, 0, len);
607 mldh->mld_type = type;
608 return mldh;
609 }
610
611 /*
612 * Add an address to the list of IP6 multicast addresses for a given interface.
613 */
614 struct in6_multi *
615 in6_addmulti(struct in6_addr *maddr6, struct ifnet *ifp,
616 int *errorp, int timer)
617 {
618 struct in6_ifaddr *ia;
619 struct in6_ifreq ifr;
620 struct in6_multi *in6m;
621 int s = splsoftnet();
622
623 *errorp = 0;
624
625 /*
626 * See if address already in list.
627 */
628 IN6_LOOKUP_MULTI(*maddr6, ifp, in6m);
629 if (in6m != NULL) {
630 /*
631 * Found it; just increment the refrence count.
632 */
633 in6m->in6m_refcount++;
634 } else {
635 /*
636 * New address; allocate a new multicast record
637 * and link it into the interface's multicast list.
638 */
639 in6m = (struct in6_multi *)
640 malloc(sizeof(*in6m), M_IPMADDR, M_NOWAIT);
641 if (in6m == NULL) {
642 splx(s);
643 *errorp = ENOBUFS;
644 return (NULL);
645 }
646
647 memset(in6m, 0, sizeof(*in6m));
648 in6m->in6m_addr = *maddr6;
649 in6m->in6m_ifp = ifp;
650 in6m->in6m_refcount = 1;
651 in6m->in6m_timer = IN6M_TIMER_UNDEF;
652 IFP_TO_IA6(ifp, ia);
653 if (ia == NULL) {
654 free(in6m, M_IPMADDR);
655 splx(s);
656 *errorp = EADDRNOTAVAIL; /* appropriate? */
657 return (NULL);
658 }
659 in6m->in6m_ia = ia;
660 IFAREF(&ia->ia_ifa); /* gain a reference */
661 LIST_INSERT_HEAD(&ia->ia6_multiaddrs, in6m, in6m_entry);
662
663 /*
664 * Ask the network driver to update its multicast reception
665 * filter appropriately for the new address.
666 */
667 sockaddr_in6_init(&ifr.ifr_addr, maddr6, 0, 0, 0);
668 if (ifp->if_ioctl == NULL)
669 *errorp = ENXIO; /* XXX: appropriate? */
670 else
671 *errorp = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, &ifr);
672 if (*errorp) {
673 LIST_REMOVE(in6m, in6m_entry);
674 free(in6m, M_IPMADDR);
675 IFAFREE(&ia->ia_ifa);
676 splx(s);
677 return (NULL);
678 }
679
680 callout_init(&in6m->in6m_timer_ch, CALLOUT_MPSAFE);
681 callout_setfunc(&in6m->in6m_timer_ch, mld_timeo, in6m);
682 in6m->in6m_timer = timer;
683 if (in6m->in6m_timer > 0) {
684 in6m->in6m_state = MLD_REPORTPENDING;
685 mld_starttimer(in6m);
686
687 splx(s);
688 return (in6m);
689 }
690
691 /*
692 * Let MLD6 know that we have joined a new IP6 multicast
693 * group.
694 */
695 mld_start_listening(in6m);
696 }
697 splx(s);
698 return (in6m);
699 }
700
701 /*
702 * Delete a multicast address record.
703 */
704 void
705 in6_delmulti(struct in6_multi *in6m)
706 {
707 struct in6_ifreq ifr;
708 struct in6_ifaddr *ia;
709 int s = splsoftnet();
710
711 mld_stoptimer(in6m);
712
713 if (--in6m->in6m_refcount == 0) {
714 /*
715 * No remaining claims to this record; let MLD6 know
716 * that we are leaving the multicast group.
717 */
718 mld_stop_listening(in6m);
719
720 /*
721 * Unlink from list.
722 */
723 LIST_REMOVE(in6m, in6m_entry);
724 if (in6m->in6m_ia != NULL) {
725 IFAFREE(&in6m->in6m_ia->ia_ifa); /* release reference */
726 in6m->in6m_ia = NULL;
727 }
728
729 /*
730 * Delete all references of this multicasting group from
731 * the membership arrays
732 */
733 for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
734 struct in6_multi_mship *imm;
735 LIST_FOREACH(imm, &ia->ia6_memberships, i6mm_chain) {
736 if (imm->i6mm_maddr == in6m)
737 imm->i6mm_maddr = NULL;
738 }
739 }
740
741 /*
742 * Notify the network driver to update its multicast
743 * reception filter.
744 */
745 sockaddr_in6_init(&ifr.ifr_addr, &in6m->in6m_addr, 0, 0, 0);
746 (*in6m->in6m_ifp->if_ioctl)(in6m->in6m_ifp, SIOCDELMULTI, &ifr);
747 callout_destroy(&in6m->in6m_timer_ch);
748 free(in6m, M_IPMADDR);
749 }
750 splx(s);
751 }
752
753
754 struct in6_multi_mship *
755 in6_joingroup(struct ifnet *ifp, struct in6_addr *addr,
756 int *errorp, int timer)
757 {
758 struct in6_multi_mship *imm;
759
760 imm = malloc(sizeof(*imm), M_IPMADDR, M_NOWAIT);
761 if (!imm) {
762 *errorp = ENOBUFS;
763 return NULL;
764 }
765
766 memset(imm, 0, sizeof(*imm));
767 imm->i6mm_maddr = in6_addmulti(addr, ifp, errorp, timer);
768 if (!imm->i6mm_maddr) {
769 /* *errorp is already set */
770 free(imm, M_IPMADDR);
771 return NULL;
772 }
773 return imm;
774 }
775
776 int
777 in6_leavegroup(struct in6_multi_mship *imm)
778 {
779
780 if (imm->i6mm_maddr) {
781 in6_delmulti(imm->i6mm_maddr);
782 }
783 free(imm, M_IPMADDR);
784 return 0;
785 }
786
787
788 /*
789 * Multicast address kludge:
790 * If there were any multicast addresses attached to this interface address,
791 * either move them to another address on this interface, or save them until
792 * such time as this interface is reconfigured for IPv6.
793 */
794 void
795 in6_savemkludge(struct in6_ifaddr *oia)
796 {
797 struct in6_ifaddr *ia;
798 struct in6_multi *in6m;
799
800 IFP_TO_IA6(oia->ia_ifp, ia);
801 if (ia) { /* there is another address */
802 KASSERT(ia != oia);
803 while ((in6m = LIST_FIRST(&oia->ia6_multiaddrs)) != NULL) {
804 LIST_REMOVE(in6m, in6m_entry);
805 IFAREF(&ia->ia_ifa);
806 IFAFREE(&in6m->in6m_ia->ia_ifa);
807 in6m->in6m_ia = ia;
808 LIST_INSERT_HEAD(&ia->ia6_multiaddrs, in6m, in6m_entry);
809 }
810 } else { /* last address on this if deleted, save */
811 struct multi6_kludge *mk;
812
813 LIST_FOREACH(mk, &in6_mk, mk_entry) {
814 if (mk->mk_ifp == oia->ia_ifp)
815 break;
816 }
817 if (mk == NULL) /* this should not happen! */
818 panic("in6_savemkludge: no kludge space");
819
820 while ((in6m = LIST_FIRST(&oia->ia6_multiaddrs)) != NULL) {
821 LIST_REMOVE(in6m, in6m_entry);
822 IFAFREE(&in6m->in6m_ia->ia_ifa); /* release reference */
823 in6m->in6m_ia = NULL;
824 LIST_INSERT_HEAD(&mk->mk_head, in6m, in6m_entry);
825 }
826 }
827 }
828
829 /*
830 * Continuation of multicast address hack:
831 * If there was a multicast group list previously saved for this interface,
832 * then we re-attach it to the first address configured on the i/f.
833 */
834 void
835 in6_restoremkludge(struct in6_ifaddr *ia, struct ifnet *ifp)
836 {
837 struct multi6_kludge *mk;
838 struct in6_multi *in6m;
839
840 LIST_FOREACH(mk, &in6_mk, mk_entry) {
841 if (mk->mk_ifp == ifp)
842 break;
843 }
844 if (mk == NULL)
845 return;
846 while ((in6m = LIST_FIRST(&mk->mk_head)) != NULL) {
847 LIST_REMOVE(in6m, in6m_entry);
848 in6m->in6m_ia = ia;
849 IFAREF(&ia->ia_ifa);
850 LIST_INSERT_HEAD(&ia->ia6_multiaddrs, in6m, in6m_entry);
851 }
852 }
853
854 /*
855 * Allocate space for the kludge at interface initialization time.
856 * Formerly, we dynamically allocated the space in in6_savemkludge() with
857 * malloc(M_WAITOK). However, it was wrong since the function could be called
858 * under an interrupt context (software timer on address lifetime expiration).
859 * Also, we cannot just give up allocating the strucutre, since the group
860 * membership structure is very complex and we need to keep it anyway.
861 * Of course, this function MUST NOT be called under an interrupt context.
862 * Specifically, it is expected to be called only from in6_ifattach(), though
863 * it is a global function.
864 */
865 void
866 in6_createmkludge(struct ifnet *ifp)
867 {
868 struct multi6_kludge *mk;
869
870 LIST_FOREACH(mk, &in6_mk, mk_entry) {
871 /* If we've already had one, do not allocate. */
872 if (mk->mk_ifp == ifp)
873 return;
874 }
875
876 mk = malloc(sizeof(*mk), M_IPMADDR, M_WAITOK);
877
878 memset(mk, 0, sizeof(*mk));
879 LIST_INIT(&mk->mk_head);
880 mk->mk_ifp = ifp;
881 LIST_INSERT_HEAD(&in6_mk, mk, mk_entry);
882 }
883
884 void
885 in6_purgemkludge(struct ifnet *ifp)
886 {
887 struct multi6_kludge *mk;
888 struct in6_multi *in6m, *next;
889
890 LIST_FOREACH(mk, &in6_mk, mk_entry) {
891 if (mk->mk_ifp == ifp)
892 break;
893 }
894 if (mk == NULL)
895 return;
896
897 /* leave from all multicast groups joined */
898 for (in6m = LIST_FIRST(&mk->mk_head); in6m != NULL; in6m = next) {
899 next = LIST_NEXT(in6m, in6m_entry);
900 in6_delmulti(in6m);
901 }
902 LIST_REMOVE(mk, mk_entry);
903 free(mk, M_IPMADDR);
904 }
Cache object: aa164ec4d9549d929a6fa1a2934e3e32
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