1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2009 Bruce Simpson.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $
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 <sys/cdefs.h>
69 #include "opt_inet.h"
70 #include "opt_inet6.h"
71
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/mbuf.h>
75 #include <sys/socket.h>
76 #include <sys/protosw.h>
77 #include <sys/sysctl.h>
78 #include <sys/kernel.h>
79 #include <sys/callout.h>
80 #include <sys/malloc.h>
81 #include <sys/module.h>
82 #include <sys/ktr.h>
83
84 #include <net/if.h>
85 #include <net/if_var.h>
86 #include <net/route.h>
87 #include <net/vnet.h>
88
89 #include <netinet/in.h>
90 #include <netinet/in_var.h>
91 #include <netinet6/in6_var.h>
92 #include <netinet/ip6.h>
93 #include <netinet6/ip6_var.h>
94 #include <netinet6/scope6_var.h>
95 #include <netinet/icmp6.h>
96 #include <netinet6/mld6.h>
97 #include <netinet6/mld6_var.h>
98
99 #include <security/mac/mac_framework.h>
100
101 #ifndef KTR_MLD
102 #define KTR_MLD KTR_INET6
103 #endif
104
105 static void mli_delete_locked(const struct ifnet *);
106 static void mld_dispatch_packet(struct mbuf *);
107 static void mld_dispatch_queue(struct mbufq *, int);
108 static void mld_final_leave(struct in6_multi *, struct mld_ifsoftc *);
109 static void mld_fasttimo_vnet(struct in6_multi_head *inmh);
110 static int mld_handle_state_change(struct in6_multi *,
111 struct mld_ifsoftc *);
112 static int mld_initial_join(struct in6_multi *, struct mld_ifsoftc *,
113 const int);
114 #ifdef KTR
115 static char * mld_rec_type_to_str(const int);
116 #endif
117 static void mld_set_version(struct mld_ifsoftc *, const int);
118 static void mld_slowtimo_vnet(void);
119 static int mld_v1_input_query(struct ifnet *, const struct ip6_hdr *,
120 /*const*/ struct mld_hdr *);
121 static int mld_v1_input_report(struct ifnet *, const struct ip6_hdr *,
122 /*const*/ struct mld_hdr *);
123 static void mld_v1_process_group_timer(struct in6_multi_head *,
124 struct in6_multi *);
125 static void mld_v1_process_querier_timers(struct mld_ifsoftc *);
126 static int mld_v1_transmit_report(struct in6_multi *, const int);
127 static void mld_v1_update_group(struct in6_multi *, const int);
128 static void mld_v2_cancel_link_timers(struct mld_ifsoftc *);
129 static void mld_v2_dispatch_general_query(struct mld_ifsoftc *);
130 static struct mbuf *
131 mld_v2_encap_report(struct ifnet *, struct mbuf *);
132 static int mld_v2_enqueue_filter_change(struct mbufq *,
133 struct in6_multi *);
134 static int mld_v2_enqueue_group_record(struct mbufq *,
135 struct in6_multi *, const int, const int, const int,
136 const int);
137 static int mld_v2_input_query(struct ifnet *, const struct ip6_hdr *,
138 struct mbuf *, struct mldv2_query *, const int, const int);
139 static int mld_v2_merge_state_changes(struct in6_multi *,
140 struct mbufq *);
141 static void mld_v2_process_group_timers(struct in6_multi_head *,
142 struct mbufq *, struct mbufq *,
143 struct in6_multi *, const int);
144 static int mld_v2_process_group_query(struct in6_multi *,
145 struct mld_ifsoftc *mli, int, struct mbuf *,
146 struct mldv2_query *, const int);
147 static int sysctl_mld_gsr(SYSCTL_HANDLER_ARGS);
148 static int sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS);
149
150 /*
151 * Normative references: RFC 2710, RFC 3590, RFC 3810.
152 *
153 * Locking:
154 * * The MLD subsystem lock ends up being system-wide for the moment,
155 * but could be per-VIMAGE later on.
156 * * The permitted lock order is: IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
157 * Any may be taken independently; if any are held at the same
158 * time, the above lock order must be followed.
159 * * IN6_MULTI_LOCK covers in_multi.
160 * * MLD_LOCK covers per-link state and any global variables in this file.
161 * * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
162 * per-link state iterators.
163 *
164 * XXX LOR PREVENTION
165 * A special case for IPv6 is the in6_setscope() routine. ip6_output()
166 * will not accept an ifp; it wants an embedded scope ID, unlike
167 * ip_output(), which happily takes the ifp given to it. The embedded
168 * scope ID is only used by MLD to select the outgoing interface.
169 *
170 * During interface attach and detach, MLD will take MLD_LOCK *after*
171 * the IF_AFDATA_LOCK.
172 * As in6_setscope() takes IF_AFDATA_LOCK then SCOPE_LOCK, we can't call
173 * it with MLD_LOCK held without triggering an LOR. A netisr with indirect
174 * dispatch could work around this, but we'd rather not do that, as it
175 * can introduce other races.
176 *
177 * As such, we exploit the fact that the scope ID is just the interface
178 * index, and embed it in the IPv6 destination address accordingly.
179 * This is potentially NOT VALID for MLDv1 reports, as they
180 * are always sent to the multicast group itself; as MLDv2
181 * reports are always sent to ff02::16, this is not an issue
182 * when MLDv2 is in use.
183 *
184 * This does not however eliminate the LOR when ip6_output() itself
185 * calls in6_setscope() internally whilst MLD_LOCK is held. This will
186 * trigger a LOR warning in WITNESS when the ifnet is detached.
187 *
188 * The right answer is probably to make IF_AFDATA_LOCK an rwlock, given
189 * how it's used across the network stack. Here we're simply exploiting
190 * the fact that MLD runs at a similar layer in the stack to scope6.c.
191 *
192 * VIMAGE:
193 * * Each in6_multi corresponds to an ifp, and each ifp corresponds
194 * to a vnet in ifp->if_vnet.
195 */
196 static struct mtx mld_mtx;
197 static MALLOC_DEFINE(M_MLD, "mld", "mld state");
198
199 #define MLD_EMBEDSCOPE(pin6, zoneid) \
200 if (IN6_IS_SCOPE_LINKLOCAL(pin6) || \
201 IN6_IS_ADDR_MC_INTFACELOCAL(pin6)) \
202 (pin6)->s6_addr16[1] = htons((zoneid) & 0xFFFF) \
203
204 /*
205 * VIMAGE-wide globals.
206 */
207 VNET_DEFINE_STATIC(struct timeval, mld_gsrdelay) = {10, 0};
208 VNET_DEFINE_STATIC(LIST_HEAD(, mld_ifsoftc), mli_head);
209 VNET_DEFINE_STATIC(int, interface_timers_running6);
210 VNET_DEFINE_STATIC(int, state_change_timers_running6);
211 VNET_DEFINE_STATIC(int, current_state_timers_running6);
212
213 #define V_mld_gsrdelay VNET(mld_gsrdelay)
214 #define V_mli_head VNET(mli_head)
215 #define V_interface_timers_running6 VNET(interface_timers_running6)
216 #define V_state_change_timers_running6 VNET(state_change_timers_running6)
217 #define V_current_state_timers_running6 VNET(current_state_timers_running6)
218
219 SYSCTL_DECL(_net_inet6); /* Note: Not in any common header. */
220
221 SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
222 "IPv6 Multicast Listener Discovery");
223
224 /*
225 * Virtualized sysctls.
226 */
227 SYSCTL_PROC(_net_inet6_mld, OID_AUTO, gsrdelay,
228 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
229 &VNET_NAME(mld_gsrdelay.tv_sec), 0, sysctl_mld_gsr, "I",
230 "Rate limit for MLDv2 Group-and-Source queries in seconds");
231
232 /*
233 * Non-virtualized sysctls.
234 */
235 static SYSCTL_NODE(_net_inet6_mld, OID_AUTO, ifinfo,
236 CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_mld_ifinfo,
237 "Per-interface MLDv2 state");
238
239 static int mld_v1enable = 1;
240 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v1enable, CTLFLAG_RWTUN,
241 &mld_v1enable, 0, "Enable fallback to MLDv1");
242
243 static int mld_v2enable = 1;
244 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v2enable, CTLFLAG_RWTUN,
245 &mld_v2enable, 0, "Enable MLDv2");
246
247 static int mld_use_allow = 1;
248 SYSCTL_INT(_net_inet6_mld, OID_AUTO, use_allow, CTLFLAG_RWTUN,
249 &mld_use_allow, 0, "Use ALLOW/BLOCK for RFC 4604 SSM joins/leaves");
250
251 /*
252 * Packed Router Alert option structure declaration.
253 */
254 struct mld_raopt {
255 struct ip6_hbh hbh;
256 struct ip6_opt pad;
257 struct ip6_opt_router ra;
258 } __packed;
259
260 /*
261 * Router Alert hop-by-hop option header.
262 */
263 static struct mld_raopt mld_ra = {
264 .hbh = { 0, 0 },
265 .pad = { .ip6o_type = IP6OPT_PADN, 0 },
266 .ra = {
267 .ip6or_type = IP6OPT_ROUTER_ALERT,
268 .ip6or_len = IP6OPT_RTALERT_LEN - 2,
269 .ip6or_value[0] = ((IP6OPT_RTALERT_MLD >> 8) & 0xFF),
270 .ip6or_value[1] = (IP6OPT_RTALERT_MLD & 0xFF)
271 }
272 };
273 static struct ip6_pktopts mld_po;
274
275 static __inline void
mld_save_context(struct mbuf * m,struct ifnet * ifp)276 mld_save_context(struct mbuf *m, struct ifnet *ifp)
277 {
278
279 #ifdef VIMAGE
280 m->m_pkthdr.PH_loc.ptr = ifp->if_vnet;
281 #endif /* VIMAGE */
282 m->m_pkthdr.rcvif = ifp;
283 m->m_pkthdr.flowid = ifp->if_index;
284 }
285
286 static __inline void
mld_scrub_context(struct mbuf * m)287 mld_scrub_context(struct mbuf *m)
288 {
289
290 m->m_pkthdr.PH_loc.ptr = NULL;
291 m->m_pkthdr.flowid = 0;
292 }
293
294 /*
295 * Restore context from a queued output chain.
296 * Return saved ifindex.
297 *
298 * VIMAGE: The assertion is there to make sure that we
299 * actually called CURVNET_SET() with what's in the mbuf chain.
300 */
301 static __inline uint32_t
mld_restore_context(struct mbuf * m)302 mld_restore_context(struct mbuf *m)
303 {
304
305 #if defined(VIMAGE) && defined(INVARIANTS)
306 KASSERT(curvnet == m->m_pkthdr.PH_loc.ptr,
307 ("%s: called when curvnet was not restored: cuvnet %p m ptr %p",
308 __func__, curvnet, m->m_pkthdr.PH_loc.ptr));
309 #endif
310 return (m->m_pkthdr.flowid);
311 }
312
313 /*
314 * Retrieve or set threshold between group-source queries in seconds.
315 *
316 * VIMAGE: Assume curvnet set by caller.
317 * SMPng: NOTE: Serialized by MLD lock.
318 */
319 static int
sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)320 sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
321 {
322 int error;
323 int i;
324
325 error = sysctl_wire_old_buffer(req, sizeof(int));
326 if (error)
327 return (error);
328
329 MLD_LOCK();
330
331 i = V_mld_gsrdelay.tv_sec;
332
333 error = sysctl_handle_int(oidp, &i, 0, req);
334 if (error || !req->newptr)
335 goto out_locked;
336
337 if (i < -1 || i >= 60) {
338 error = EINVAL;
339 goto out_locked;
340 }
341
342 CTR2(KTR_MLD, "change mld_gsrdelay from %d to %d",
343 V_mld_gsrdelay.tv_sec, i);
344 V_mld_gsrdelay.tv_sec = i;
345
346 out_locked:
347 MLD_UNLOCK();
348 return (error);
349 }
350
351 /*
352 * Expose struct mld_ifsoftc to userland, keyed by ifindex.
353 * For use by ifmcstat(8).
354 *
355 * SMPng: NOTE: Does an unlocked ifindex space read.
356 * VIMAGE: Assume curvnet set by caller. The node handler itself
357 * is not directly virtualized.
358 */
359 static int
sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)360 sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
361 {
362 int *name;
363 int error;
364 u_int namelen;
365 struct ifnet *ifp;
366 struct mld_ifsoftc *mli;
367
368 name = (int *)arg1;
369 namelen = arg2;
370
371 if (req->newptr != NULL)
372 return (EPERM);
373
374 if (namelen != 1)
375 return (EINVAL);
376
377 error = sysctl_wire_old_buffer(req, sizeof(struct mld_ifinfo));
378 if (error)
379 return (error);
380
381 IN6_MULTI_LOCK();
382 IN6_MULTI_LIST_LOCK();
383 MLD_LOCK();
384
385 if (name[0] <= 0 || name[0] > V_if_index) {
386 error = ENOENT;
387 goto out_locked;
388 }
389
390 error = ENOENT;
391
392 ifp = ifnet_byindex(name[0]);
393 if (ifp == NULL)
394 goto out_locked;
395
396 LIST_FOREACH(mli, &V_mli_head, mli_link) {
397 if (ifp == mli->mli_ifp) {
398 struct mld_ifinfo info;
399
400 info.mli_version = mli->mli_version;
401 info.mli_v1_timer = mli->mli_v1_timer;
402 info.mli_v2_timer = mli->mli_v2_timer;
403 info.mli_flags = mli->mli_flags;
404 info.mli_rv = mli->mli_rv;
405 info.mli_qi = mli->mli_qi;
406 info.mli_qri = mli->mli_qri;
407 info.mli_uri = mli->mli_uri;
408 error = SYSCTL_OUT(req, &info, sizeof(info));
409 break;
410 }
411 }
412
413 out_locked:
414 MLD_UNLOCK();
415 IN6_MULTI_LIST_UNLOCK();
416 IN6_MULTI_UNLOCK();
417 return (error);
418 }
419
420 /*
421 * Dispatch an entire queue of pending packet chains.
422 * VIMAGE: Assumes the vnet pointer has been set.
423 */
424 static void
mld_dispatch_queue(struct mbufq * mq,int limit)425 mld_dispatch_queue(struct mbufq *mq, int limit)
426 {
427 struct mbuf *m;
428
429 while ((m = mbufq_dequeue(mq)) != NULL) {
430 CTR3(KTR_MLD, "%s: dispatch %p from %p", __func__, mq, m);
431 mld_dispatch_packet(m);
432 if (--limit == 0)
433 break;
434 }
435 }
436
437 /*
438 * Filter outgoing MLD report state by group.
439 *
440 * Reports are ALWAYS suppressed for ALL-HOSTS (ff02::1)
441 * and node-local addresses. However, kernel and socket consumers
442 * always embed the KAME scope ID in the address provided, so strip it
443 * when performing comparison.
444 * Note: This is not the same as the *multicast* scope.
445 *
446 * Return zero if the given group is one for which MLD reports
447 * should be suppressed, or non-zero if reports should be issued.
448 */
449 static __inline int
mld_is_addr_reported(const struct in6_addr * addr)450 mld_is_addr_reported(const struct in6_addr *addr)
451 {
452
453 KASSERT(IN6_IS_ADDR_MULTICAST(addr), ("%s: not multicast", __func__));
454
455 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_NODELOCAL)
456 return (0);
457
458 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_LINKLOCAL) {
459 struct in6_addr tmp = *addr;
460 in6_clearscope(&tmp);
461 if (IN6_ARE_ADDR_EQUAL(&tmp, &in6addr_linklocal_allnodes))
462 return (0);
463 }
464
465 return (1);
466 }
467
468 /*
469 * Attach MLD when PF_INET6 is attached to an interface. Assumes that the
470 * current VNET is set by the caller.
471 */
472 struct mld_ifsoftc *
mld_domifattach(struct ifnet * ifp)473 mld_domifattach(struct ifnet *ifp)
474 {
475 struct mld_ifsoftc *mli;
476
477 CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp, if_name(ifp));
478
479 mli = malloc(sizeof(struct mld_ifsoftc), M_MLD, M_WAITOK | M_ZERO);
480 mli->mli_ifp = ifp;
481 mli->mli_version = MLD_VERSION_2;
482 mli->mli_flags = 0;
483 mli->mli_rv = MLD_RV_INIT;
484 mli->mli_qi = MLD_QI_INIT;
485 mli->mli_qri = MLD_QRI_INIT;
486 mli->mli_uri = MLD_URI_INIT;
487 mbufq_init(&mli->mli_gq, MLD_MAX_RESPONSE_PACKETS);
488 if ((ifp->if_flags & IFF_MULTICAST) == 0)
489 mli->mli_flags |= MLIF_SILENT;
490 if (mld_use_allow)
491 mli->mli_flags |= MLIF_USEALLOW;
492
493 MLD_LOCK();
494 LIST_INSERT_HEAD(&V_mli_head, mli, mli_link);
495 MLD_UNLOCK();
496
497 return (mli);
498 }
499
500 /*
501 * Hook for ifdetach.
502 *
503 * NOTE: Some finalization tasks need to run before the protocol domain
504 * is detached, but also before the link layer does its cleanup.
505 * Run before link-layer cleanup; cleanup groups, but do not free MLD state.
506 *
507 * SMPng: Caller must hold IN6_MULTI_LOCK().
508 * Must take IF_ADDR_LOCK() to cover if_multiaddrs iterator.
509 * XXX This routine is also bitten by unlocked ifma_protospec access.
510 */
511 void
mld_ifdetach(struct ifnet * ifp,struct in6_multi_head * inmh)512 mld_ifdetach(struct ifnet *ifp, struct in6_multi_head *inmh)
513 {
514 struct epoch_tracker et;
515 struct mld_ifsoftc *mli;
516 struct ifmultiaddr *ifma;
517 struct in6_multi *inm;
518
519 CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp,
520 if_name(ifp));
521
522 IN6_MULTI_LIST_LOCK_ASSERT();
523 MLD_LOCK();
524
525 mli = MLD_IFINFO(ifp);
526 IF_ADDR_WLOCK(ifp);
527 /*
528 * Extract list of in6_multi associated with the detaching ifp
529 * which the PF_INET6 layer is about to release.
530 */
531 NET_EPOCH_ENTER(et);
532 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
533 inm = in6m_ifmultiaddr_get_inm(ifma);
534 if (inm == NULL)
535 continue;
536 in6m_disconnect_locked(inmh, inm);
537
538 if (mli->mli_version == MLD_VERSION_2) {
539 in6m_clear_recorded(inm);
540
541 /*
542 * We need to release the final reference held
543 * for issuing the INCLUDE {}.
544 */
545 if (inm->in6m_state == MLD_LEAVING_MEMBER) {
546 inm->in6m_state = MLD_NOT_MEMBER;
547 in6m_rele_locked(inmh, inm);
548 }
549 }
550 }
551 NET_EPOCH_EXIT(et);
552 IF_ADDR_WUNLOCK(ifp);
553 MLD_UNLOCK();
554 }
555
556 /*
557 * Hook for domifdetach.
558 * Runs after link-layer cleanup; free MLD state.
559 *
560 * SMPng: Normally called with IF_AFDATA_LOCK held.
561 */
562 void
mld_domifdetach(struct ifnet * ifp)563 mld_domifdetach(struct ifnet *ifp)
564 {
565
566 CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
567 __func__, ifp, if_name(ifp));
568
569 MLD_LOCK();
570 mli_delete_locked(ifp);
571 MLD_UNLOCK();
572 }
573
574 static void
mli_delete_locked(const struct ifnet * ifp)575 mli_delete_locked(const struct ifnet *ifp)
576 {
577 struct mld_ifsoftc *mli, *tmli;
578
579 CTR3(KTR_MLD, "%s: freeing mld_ifsoftc for ifp %p(%s)",
580 __func__, ifp, if_name(ifp));
581
582 MLD_LOCK_ASSERT();
583
584 LIST_FOREACH_SAFE(mli, &V_mli_head, mli_link, tmli) {
585 if (mli->mli_ifp == ifp) {
586 /*
587 * Free deferred General Query responses.
588 */
589 mbufq_drain(&mli->mli_gq);
590
591 LIST_REMOVE(mli, mli_link);
592
593 free(mli, M_MLD);
594 return;
595 }
596 }
597 }
598
599 /*
600 * Process a received MLDv1 general or address-specific query.
601 * Assumes that the query header has been pulled up to sizeof(mld_hdr).
602 *
603 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
604 * mld_addr. This is OK as we own the mbuf chain.
605 */
606 static int
mld_v1_input_query(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)607 mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
608 /*const*/ struct mld_hdr *mld)
609 {
610 struct ifmultiaddr *ifma;
611 struct mld_ifsoftc *mli;
612 struct in6_multi *inm;
613 int is_general_query;
614 uint16_t timer;
615 #ifdef KTR
616 char ip6tbuf[INET6_ADDRSTRLEN];
617 #endif
618
619 NET_EPOCH_ASSERT();
620
621 is_general_query = 0;
622
623 if (!mld_v1enable) {
624 CTR3(KTR_MLD, "ignore v1 query %s on ifp %p(%s)",
625 ip6_sprintf(ip6tbuf, &mld->mld_addr),
626 ifp, if_name(ifp));
627 return (0);
628 }
629
630 /*
631 * RFC3810 Section 6.2: MLD queries must originate from
632 * a router's link-local address.
633 */
634 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
635 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
636 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
637 ifp, if_name(ifp));
638 return (0);
639 }
640
641 /*
642 * Do address field validation upfront before we accept
643 * the query.
644 */
645 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
646 /*
647 * MLDv1 General Query.
648 * If this was not sent to the all-nodes group, ignore it.
649 */
650 struct in6_addr dst;
651
652 dst = ip6->ip6_dst;
653 in6_clearscope(&dst);
654 if (!IN6_ARE_ADDR_EQUAL(&dst, &in6addr_linklocal_allnodes))
655 return (EINVAL);
656 is_general_query = 1;
657 } else {
658 /*
659 * Embed scope ID of receiving interface in MLD query for
660 * lookup whilst we don't hold other locks.
661 */
662 in6_setscope(&mld->mld_addr, ifp, NULL);
663 }
664
665 IN6_MULTI_LIST_LOCK();
666 MLD_LOCK();
667
668 /*
669 * Switch to MLDv1 host compatibility mode.
670 */
671 mli = MLD_IFINFO(ifp);
672 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
673 mld_set_version(mli, MLD_VERSION_1);
674
675 timer = (ntohs(mld->mld_maxdelay) * PR_FASTHZ) / MLD_TIMER_SCALE;
676 if (timer == 0)
677 timer = 1;
678
679 if (is_general_query) {
680 /*
681 * For each reporting group joined on this
682 * interface, kick the report timer.
683 */
684 CTR2(KTR_MLD, "process v1 general query on ifp %p(%s)",
685 ifp, if_name(ifp));
686 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
687 inm = in6m_ifmultiaddr_get_inm(ifma);
688 if (inm == NULL)
689 continue;
690 mld_v1_update_group(inm, timer);
691 }
692 } else {
693 /*
694 * MLDv1 Group-Specific Query.
695 * If this is a group-specific MLDv1 query, we need only
696 * look up the single group to process it.
697 */
698 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
699 if (inm != NULL) {
700 CTR3(KTR_MLD, "process v1 query %s on ifp %p(%s)",
701 ip6_sprintf(ip6tbuf, &mld->mld_addr),
702 ifp, if_name(ifp));
703 mld_v1_update_group(inm, timer);
704 }
705 /* XXX Clear embedded scope ID as userland won't expect it. */
706 in6_clearscope(&mld->mld_addr);
707 }
708
709 MLD_UNLOCK();
710 IN6_MULTI_LIST_UNLOCK();
711
712 return (0);
713 }
714
715 /*
716 * Update the report timer on a group in response to an MLDv1 query.
717 *
718 * If we are becoming the reporting member for this group, start the timer.
719 * If we already are the reporting member for this group, and timer is
720 * below the threshold, reset it.
721 *
722 * We may be updating the group for the first time since we switched
723 * to MLDv2. If we are, then we must clear any recorded source lists,
724 * and transition to REPORTING state; the group timer is overloaded
725 * for group and group-source query responses.
726 *
727 * Unlike MLDv2, the delay per group should be jittered
728 * to avoid bursts of MLDv1 reports.
729 */
730 static void
mld_v1_update_group(struct in6_multi * inm,const int timer)731 mld_v1_update_group(struct in6_multi *inm, const int timer)
732 {
733 #ifdef KTR
734 char ip6tbuf[INET6_ADDRSTRLEN];
735 #endif
736
737 CTR4(KTR_MLD, "%s: %s/%s timer=%d", __func__,
738 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
739 if_name(inm->in6m_ifp), timer);
740
741 IN6_MULTI_LIST_LOCK_ASSERT();
742
743 switch (inm->in6m_state) {
744 case MLD_NOT_MEMBER:
745 case MLD_SILENT_MEMBER:
746 break;
747 case MLD_REPORTING_MEMBER:
748 if (inm->in6m_timer != 0 &&
749 inm->in6m_timer <= timer) {
750 CTR1(KTR_MLD, "%s: REPORTING and timer running, "
751 "skipping.", __func__);
752 break;
753 }
754 /* FALLTHROUGH */
755 case MLD_SG_QUERY_PENDING_MEMBER:
756 case MLD_G_QUERY_PENDING_MEMBER:
757 case MLD_IDLE_MEMBER:
758 case MLD_LAZY_MEMBER:
759 case MLD_AWAKENING_MEMBER:
760 CTR1(KTR_MLD, "%s: ->REPORTING", __func__);
761 inm->in6m_state = MLD_REPORTING_MEMBER;
762 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
763 V_current_state_timers_running6 = 1;
764 break;
765 case MLD_SLEEPING_MEMBER:
766 CTR1(KTR_MLD, "%s: ->AWAKENING", __func__);
767 inm->in6m_state = MLD_AWAKENING_MEMBER;
768 break;
769 case MLD_LEAVING_MEMBER:
770 break;
771 }
772 }
773
774 /*
775 * Process a received MLDv2 general, group-specific or
776 * group-and-source-specific query.
777 *
778 * Assumes that mld points to a struct mldv2_query which is stored in
779 * contiguous memory.
780 *
781 * Return 0 if successful, otherwise an appropriate error code is returned.
782 */
783 static int
mld_v2_input_query(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mbuf * m,struct mldv2_query * mld,const int off,const int icmp6len)784 mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
785 struct mbuf *m, struct mldv2_query *mld, const int off, const int icmp6len)
786 {
787 struct mld_ifsoftc *mli;
788 struct in6_multi *inm;
789 uint32_t maxdelay, nsrc, qqi;
790 int is_general_query;
791 uint16_t timer;
792 uint8_t qrv;
793 #ifdef KTR
794 char ip6tbuf[INET6_ADDRSTRLEN];
795 #endif
796
797 NET_EPOCH_ASSERT();
798
799 if (!mld_v2enable) {
800 CTR3(KTR_MLD, "ignore v2 query src %s on ifp %p(%s)",
801 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
802 ifp, if_name(ifp));
803 return (0);
804 }
805
806 /*
807 * RFC3810 Section 6.2: MLD queries must originate from
808 * a router's link-local address.
809 */
810 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
811 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
812 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
813 ifp, if_name(ifp));
814 return (0);
815 }
816
817 is_general_query = 0;
818
819 CTR2(KTR_MLD, "input v2 query on ifp %p(%s)", ifp, if_name(ifp));
820
821 maxdelay = ntohs(mld->mld_maxdelay); /* in 1/10ths of a second */
822 if (maxdelay >= 32768) {
823 maxdelay = (MLD_MRC_MANT(maxdelay) | 0x1000) <<
824 (MLD_MRC_EXP(maxdelay) + 3);
825 }
826 timer = (maxdelay * PR_FASTHZ) / MLD_TIMER_SCALE;
827 if (timer == 0)
828 timer = 1;
829
830 qrv = MLD_QRV(mld->mld_misc);
831 if (qrv < 2) {
832 CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
833 qrv, MLD_RV_INIT);
834 qrv = MLD_RV_INIT;
835 }
836
837 qqi = mld->mld_qqi;
838 if (qqi >= 128) {
839 qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
840 (MLD_QQIC_EXP(mld->mld_qqi) + 3);
841 }
842
843 nsrc = ntohs(mld->mld_numsrc);
844 if (nsrc > MLD_MAX_GS_SOURCES)
845 return (EMSGSIZE);
846 if (icmp6len < sizeof(struct mldv2_query) +
847 (nsrc * sizeof(struct in6_addr)))
848 return (EMSGSIZE);
849
850 /*
851 * Do further input validation upfront to avoid resetting timers
852 * should we need to discard this query.
853 */
854 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
855 /*
856 * A general query with a source list has undefined
857 * behaviour; discard it.
858 */
859 if (nsrc > 0)
860 return (EINVAL);
861 is_general_query = 1;
862 } else {
863 /*
864 * Embed scope ID of receiving interface in MLD query for
865 * lookup whilst we don't hold other locks (due to KAME
866 * locking lameness). We own this mbuf chain just now.
867 */
868 in6_setscope(&mld->mld_addr, ifp, NULL);
869 }
870
871 IN6_MULTI_LIST_LOCK();
872 MLD_LOCK();
873
874 mli = MLD_IFINFO(ifp);
875 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
876
877 /*
878 * Discard the v2 query if we're in Compatibility Mode.
879 * The RFC is pretty clear that hosts need to stay in MLDv1 mode
880 * until the Old Version Querier Present timer expires.
881 */
882 if (mli->mli_version != MLD_VERSION_2)
883 goto out_locked;
884
885 mld_set_version(mli, MLD_VERSION_2);
886 mli->mli_rv = qrv;
887 mli->mli_qi = qqi;
888 mli->mli_qri = maxdelay;
889
890 CTR4(KTR_MLD, "%s: qrv %d qi %d maxdelay %d", __func__, qrv, qqi,
891 maxdelay);
892
893 if (is_general_query) {
894 /*
895 * MLDv2 General Query.
896 *
897 * Schedule a current-state report on this ifp for
898 * all groups, possibly containing source lists.
899 *
900 * If there is a pending General Query response
901 * scheduled earlier than the selected delay, do
902 * not schedule any other reports.
903 * Otherwise, reset the interface timer.
904 */
905 CTR2(KTR_MLD, "process v2 general query on ifp %p(%s)",
906 ifp, if_name(ifp));
907 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer) {
908 mli->mli_v2_timer = MLD_RANDOM_DELAY(timer);
909 V_interface_timers_running6 = 1;
910 }
911 } else {
912 /*
913 * MLDv2 Group-specific or Group-and-source-specific Query.
914 *
915 * Group-source-specific queries are throttled on
916 * a per-group basis to defeat denial-of-service attempts.
917 * Queries for groups we are not a member of on this
918 * link are simply ignored.
919 */
920 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
921 if (inm == NULL)
922 goto out_locked;
923 if (nsrc > 0) {
924 if (!ratecheck(&inm->in6m_lastgsrtv,
925 &V_mld_gsrdelay)) {
926 CTR1(KTR_MLD, "%s: GS query throttled.",
927 __func__);
928 goto out_locked;
929 }
930 }
931 CTR2(KTR_MLD, "process v2 group query on ifp %p(%s)",
932 ifp, if_name(ifp));
933 /*
934 * If there is a pending General Query response
935 * scheduled sooner than the selected delay, no
936 * further report need be scheduled.
937 * Otherwise, prepare to respond to the
938 * group-specific or group-and-source query.
939 */
940 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer)
941 mld_v2_process_group_query(inm, mli, timer, m, mld, off);
942
943 /* XXX Clear embedded scope ID as userland won't expect it. */
944 in6_clearscope(&mld->mld_addr);
945 }
946
947 out_locked:
948 MLD_UNLOCK();
949 IN6_MULTI_LIST_UNLOCK();
950
951 return (0);
952 }
953
954 /*
955 * Process a received MLDv2 group-specific or group-and-source-specific
956 * query.
957 * Return <0 if any error occurred. Currently this is ignored.
958 */
959 static int
mld_v2_process_group_query(struct in6_multi * inm,struct mld_ifsoftc * mli,int timer,struct mbuf * m0,struct mldv2_query * mld,const int off)960 mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifsoftc *mli,
961 int timer, struct mbuf *m0, struct mldv2_query *mld, const int off)
962 {
963 int retval;
964 uint16_t nsrc;
965
966 IN6_MULTI_LIST_LOCK_ASSERT();
967 MLD_LOCK_ASSERT();
968
969 retval = 0;
970
971 switch (inm->in6m_state) {
972 case MLD_NOT_MEMBER:
973 case MLD_SILENT_MEMBER:
974 case MLD_SLEEPING_MEMBER:
975 case MLD_LAZY_MEMBER:
976 case MLD_AWAKENING_MEMBER:
977 case MLD_IDLE_MEMBER:
978 case MLD_LEAVING_MEMBER:
979 return (retval);
980 break;
981 case MLD_REPORTING_MEMBER:
982 case MLD_G_QUERY_PENDING_MEMBER:
983 case MLD_SG_QUERY_PENDING_MEMBER:
984 break;
985 }
986
987 nsrc = ntohs(mld->mld_numsrc);
988
989 /* Length should be checked by calling function. */
990 KASSERT((m0->m_flags & M_PKTHDR) == 0 ||
991 m0->m_pkthdr.len >= off + sizeof(struct mldv2_query) +
992 nsrc * sizeof(struct in6_addr),
993 ("mldv2 packet is too short: (%d bytes < %zd bytes, m=%p)",
994 m0->m_pkthdr.len, off + sizeof(struct mldv2_query) +
995 nsrc * sizeof(struct in6_addr), m0));
996
997 /*
998 * Deal with group-specific queries upfront.
999 * If any group query is already pending, purge any recorded
1000 * source-list state if it exists, and schedule a query response
1001 * for this group-specific query.
1002 */
1003 if (nsrc == 0) {
1004 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
1005 inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER) {
1006 in6m_clear_recorded(inm);
1007 timer = min(inm->in6m_timer, timer);
1008 }
1009 inm->in6m_state = MLD_G_QUERY_PENDING_MEMBER;
1010 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1011 V_current_state_timers_running6 = 1;
1012 return (retval);
1013 }
1014
1015 /*
1016 * Deal with the case where a group-and-source-specific query has
1017 * been received but a group-specific query is already pending.
1018 */
1019 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER) {
1020 timer = min(inm->in6m_timer, timer);
1021 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1022 V_current_state_timers_running6 = 1;
1023 return (retval);
1024 }
1025
1026 /*
1027 * Finally, deal with the case where a group-and-source-specific
1028 * query has been received, where a response to a previous g-s-r
1029 * query exists, or none exists.
1030 * In this case, we need to parse the source-list which the Querier
1031 * has provided us with and check if we have any source list filter
1032 * entries at T1 for these sources. If we do not, there is no need
1033 * schedule a report and the query may be dropped.
1034 * If we do, we must record them and schedule a current-state
1035 * report for those sources.
1036 */
1037 if (inm->in6m_nsrc > 0) {
1038 struct in6_addr srcaddr;
1039 int i, nrecorded;
1040 int soff;
1041
1042 soff = off + sizeof(struct mldv2_query);
1043 nrecorded = 0;
1044 for (i = 0; i < nsrc; i++) {
1045 m_copydata(m0, soff, sizeof(struct in6_addr),
1046 (caddr_t)&srcaddr);
1047 retval = in6m_record_source(inm, &srcaddr);
1048 if (retval < 0)
1049 break;
1050 nrecorded += retval;
1051 soff += sizeof(struct in6_addr);
1052 }
1053 if (nrecorded > 0) {
1054 CTR1(KTR_MLD,
1055 "%s: schedule response to SG query", __func__);
1056 inm->in6m_state = MLD_SG_QUERY_PENDING_MEMBER;
1057 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1058 V_current_state_timers_running6 = 1;
1059 }
1060 }
1061
1062 return (retval);
1063 }
1064
1065 /*
1066 * Process a received MLDv1 host membership report.
1067 * Assumes mld points to mld_hdr in pulled up mbuf chain.
1068 *
1069 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
1070 * mld_addr. This is OK as we own the mbuf chain.
1071 */
1072 static int
mld_v1_input_report(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)1073 mld_v1_input_report(struct ifnet *ifp, const struct ip6_hdr *ip6,
1074 /*const*/ struct mld_hdr *mld)
1075 {
1076 struct in6_addr src, dst;
1077 struct in6_ifaddr *ia;
1078 struct in6_multi *inm;
1079 #ifdef KTR
1080 char ip6tbuf[INET6_ADDRSTRLEN];
1081 #endif
1082
1083 NET_EPOCH_ASSERT();
1084
1085 if (!mld_v1enable) {
1086 CTR3(KTR_MLD, "ignore v1 report %s on ifp %p(%s)",
1087 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1088 ifp, if_name(ifp));
1089 return (0);
1090 }
1091
1092 if (ifp->if_flags & IFF_LOOPBACK)
1093 return (0);
1094
1095 /*
1096 * MLDv1 reports must originate from a host's link-local address,
1097 * or the unspecified address (when booting).
1098 */
1099 src = ip6->ip6_src;
1100 in6_clearscope(&src);
1101 if (!IN6_IS_SCOPE_LINKLOCAL(&src) && !IN6_IS_ADDR_UNSPECIFIED(&src)) {
1102 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
1103 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
1104 ifp, if_name(ifp));
1105 return (EINVAL);
1106 }
1107
1108 /*
1109 * RFC2710 Section 4: MLDv1 reports must pertain to a multicast
1110 * group, and must be directed to the group itself.
1111 */
1112 dst = ip6->ip6_dst;
1113 in6_clearscope(&dst);
1114 if (!IN6_IS_ADDR_MULTICAST(&mld->mld_addr) ||
1115 !IN6_ARE_ADDR_EQUAL(&mld->mld_addr, &dst)) {
1116 CTR3(KTR_MLD, "ignore v1 query dst %s on ifp %p(%s)",
1117 ip6_sprintf(ip6tbuf, &ip6->ip6_dst),
1118 ifp, if_name(ifp));
1119 return (EINVAL);
1120 }
1121
1122 /*
1123 * Make sure we don't hear our own membership report, as fast
1124 * leave requires knowing that we are the only member of a
1125 * group. Assume we used the link-local address if available,
1126 * otherwise look for ::.
1127 *
1128 * XXX Note that scope ID comparison is needed for the address
1129 * returned by in6ifa_ifpforlinklocal(), but SHOULD NOT be
1130 * performed for the on-wire address.
1131 */
1132 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1133 if ((ia && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, IA6_IN6(ia))) ||
1134 (ia == NULL && IN6_IS_ADDR_UNSPECIFIED(&src))) {
1135 if (ia != NULL)
1136 ifa_free(&ia->ia_ifa);
1137 return (0);
1138 }
1139 if (ia != NULL)
1140 ifa_free(&ia->ia_ifa);
1141
1142 CTR3(KTR_MLD, "process v1 report %s on ifp %p(%s)",
1143 ip6_sprintf(ip6tbuf, &mld->mld_addr), ifp, if_name(ifp));
1144
1145 /*
1146 * Embed scope ID of receiving interface in MLD query for lookup
1147 * whilst we don't hold other locks (due to KAME locking lameness).
1148 */
1149 if (!IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr))
1150 in6_setscope(&mld->mld_addr, ifp, NULL);
1151
1152 IN6_MULTI_LIST_LOCK();
1153 MLD_LOCK();
1154
1155 /*
1156 * MLDv1 report suppression.
1157 * If we are a member of this group, and our membership should be
1158 * reported, and our group timer is pending or about to be reset,
1159 * stop our group timer by transitioning to the 'lazy' state.
1160 */
1161 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
1162 if (inm != NULL) {
1163 struct mld_ifsoftc *mli;
1164
1165 mli = inm->in6m_mli;
1166 KASSERT(mli != NULL,
1167 ("%s: no mli for ifp %p", __func__, ifp));
1168
1169 /*
1170 * If we are in MLDv2 host mode, do not allow the
1171 * other host's MLDv1 report to suppress our reports.
1172 */
1173 if (mli->mli_version == MLD_VERSION_2)
1174 goto out_locked;
1175
1176 inm->in6m_timer = 0;
1177
1178 switch (inm->in6m_state) {
1179 case MLD_NOT_MEMBER:
1180 case MLD_SILENT_MEMBER:
1181 case MLD_SLEEPING_MEMBER:
1182 break;
1183 case MLD_REPORTING_MEMBER:
1184 case MLD_IDLE_MEMBER:
1185 case MLD_AWAKENING_MEMBER:
1186 CTR3(KTR_MLD,
1187 "report suppressed for %s on ifp %p(%s)",
1188 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1189 ifp, if_name(ifp));
1190 case MLD_LAZY_MEMBER:
1191 inm->in6m_state = MLD_LAZY_MEMBER;
1192 break;
1193 case MLD_G_QUERY_PENDING_MEMBER:
1194 case MLD_SG_QUERY_PENDING_MEMBER:
1195 case MLD_LEAVING_MEMBER:
1196 break;
1197 }
1198 }
1199
1200 out_locked:
1201 MLD_UNLOCK();
1202 IN6_MULTI_LIST_UNLOCK();
1203
1204 /* XXX Clear embedded scope ID as userland won't expect it. */
1205 in6_clearscope(&mld->mld_addr);
1206
1207 return (0);
1208 }
1209
1210 /*
1211 * MLD input path.
1212 *
1213 * Assume query messages which fit in a single ICMPv6 message header
1214 * have been pulled up.
1215 * Assume that userland will want to see the message, even if it
1216 * otherwise fails kernel input validation; do not free it.
1217 * Pullup may however free the mbuf chain m if it fails.
1218 *
1219 * Return IPPROTO_DONE if we freed m. Otherwise, return 0.
1220 */
1221 int
mld_input(struct mbuf ** mp,int off,int icmp6len)1222 mld_input(struct mbuf **mp, int off, int icmp6len)
1223 {
1224 struct ifnet *ifp;
1225 struct ip6_hdr *ip6;
1226 struct mbuf *m;
1227 struct mld_hdr *mld;
1228 int mldlen;
1229
1230 m = *mp;
1231 CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
1232
1233 ifp = m->m_pkthdr.rcvif;
1234
1235 /* Pullup to appropriate size. */
1236 if (m->m_len < off + sizeof(*mld)) {
1237 m = m_pullup(m, off + sizeof(*mld));
1238 if (m == NULL) {
1239 ICMP6STAT_INC(icp6s_badlen);
1240 return (IPPROTO_DONE);
1241 }
1242 }
1243 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1244 if (mld->mld_type == MLD_LISTENER_QUERY &&
1245 icmp6len >= sizeof(struct mldv2_query)) {
1246 mldlen = sizeof(struct mldv2_query);
1247 } else {
1248 mldlen = sizeof(struct mld_hdr);
1249 }
1250 if (m->m_len < off + mldlen) {
1251 m = m_pullup(m, off + mldlen);
1252 if (m == NULL) {
1253 ICMP6STAT_INC(icp6s_badlen);
1254 return (IPPROTO_DONE);
1255 }
1256 }
1257 *mp = m;
1258 ip6 = mtod(m, struct ip6_hdr *);
1259 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1260
1261 /*
1262 * Userland needs to see all of this traffic for implementing
1263 * the endpoint discovery portion of multicast routing.
1264 */
1265 switch (mld->mld_type) {
1266 case MLD_LISTENER_QUERY:
1267 icmp6_ifstat_inc(ifp, ifs6_in_mldquery);
1268 if (icmp6len == sizeof(struct mld_hdr)) {
1269 if (mld_v1_input_query(ifp, ip6, mld) != 0)
1270 return (0);
1271 } else if (icmp6len >= sizeof(struct mldv2_query)) {
1272 if (mld_v2_input_query(ifp, ip6, m,
1273 (struct mldv2_query *)mld, off, icmp6len) != 0)
1274 return (0);
1275 }
1276 break;
1277 case MLD_LISTENER_REPORT:
1278 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1279 if (mld_v1_input_report(ifp, ip6, mld) != 0)
1280 return (0);
1281 break;
1282 case MLDV2_LISTENER_REPORT:
1283 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1284 break;
1285 case MLD_LISTENER_DONE:
1286 icmp6_ifstat_inc(ifp, ifs6_in_mlddone);
1287 break;
1288 default:
1289 break;
1290 }
1291
1292 return (0);
1293 }
1294
1295 /*
1296 * Fast timeout handler (global).
1297 * VIMAGE: Timeout handlers are expected to service all vimages.
1298 */
1299 void
mld_fasttimo(void)1300 mld_fasttimo(void)
1301 {
1302 struct in6_multi_head inmh;
1303 VNET_ITERATOR_DECL(vnet_iter);
1304
1305 SLIST_INIT(&inmh);
1306
1307 VNET_LIST_RLOCK_NOSLEEP();
1308 VNET_FOREACH(vnet_iter) {
1309 CURVNET_SET(vnet_iter);
1310 mld_fasttimo_vnet(&inmh);
1311 CURVNET_RESTORE();
1312 }
1313 VNET_LIST_RUNLOCK_NOSLEEP();
1314 in6m_release_list_deferred(&inmh);
1315 }
1316
1317 /*
1318 * Fast timeout handler (per-vnet).
1319 *
1320 * VIMAGE: Assume caller has set up our curvnet.
1321 */
1322 static void
mld_fasttimo_vnet(struct in6_multi_head * inmh)1323 mld_fasttimo_vnet(struct in6_multi_head *inmh)
1324 {
1325 struct epoch_tracker et;
1326 struct mbufq scq; /* State-change packets */
1327 struct mbufq qrq; /* Query response packets */
1328 struct ifnet *ifp;
1329 struct mld_ifsoftc *mli;
1330 struct ifmultiaddr *ifma;
1331 struct in6_multi *inm;
1332 int uri_fasthz;
1333
1334 uri_fasthz = 0;
1335
1336 /*
1337 * Quick check to see if any work needs to be done, in order to
1338 * minimize the overhead of fasttimo processing.
1339 * SMPng: XXX Unlocked reads.
1340 */
1341 if (!V_current_state_timers_running6 &&
1342 !V_interface_timers_running6 &&
1343 !V_state_change_timers_running6)
1344 return;
1345
1346 IN6_MULTI_LIST_LOCK();
1347 MLD_LOCK();
1348
1349 /*
1350 * MLDv2 General Query response timer processing.
1351 */
1352 if (V_interface_timers_running6) {
1353 CTR1(KTR_MLD, "%s: interface timers running", __func__);
1354
1355 V_interface_timers_running6 = 0;
1356 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1357 if (mli->mli_v2_timer == 0) {
1358 /* Do nothing. */
1359 } else if (--mli->mli_v2_timer == 0) {
1360 mld_v2_dispatch_general_query(mli);
1361 } else {
1362 V_interface_timers_running6 = 1;
1363 }
1364 }
1365 }
1366
1367 if (!V_current_state_timers_running6 &&
1368 !V_state_change_timers_running6)
1369 goto out_locked;
1370
1371 V_current_state_timers_running6 = 0;
1372 V_state_change_timers_running6 = 0;
1373
1374 CTR1(KTR_MLD, "%s: state change timers running", __func__);
1375
1376 /*
1377 * MLD host report and state-change timer processing.
1378 * Note: Processing a v2 group timer may remove a node.
1379 */
1380 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1381 ifp = mli->mli_ifp;
1382
1383 if (mli->mli_version == MLD_VERSION_2) {
1384 uri_fasthz = MLD_RANDOM_DELAY(mli->mli_uri *
1385 PR_FASTHZ);
1386 mbufq_init(&qrq, MLD_MAX_G_GS_PACKETS);
1387 mbufq_init(&scq, MLD_MAX_STATE_CHANGE_PACKETS);
1388 }
1389
1390 NET_EPOCH_ENTER(et);
1391 IF_ADDR_WLOCK(ifp);
1392 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1393 inm = in6m_ifmultiaddr_get_inm(ifma);
1394 if (inm == NULL)
1395 continue;
1396 switch (mli->mli_version) {
1397 case MLD_VERSION_1:
1398 mld_v1_process_group_timer(inmh, inm);
1399 break;
1400 case MLD_VERSION_2:
1401 mld_v2_process_group_timers(inmh, &qrq,
1402 &scq, inm, uri_fasthz);
1403 break;
1404 }
1405 }
1406 IF_ADDR_WUNLOCK(ifp);
1407
1408 switch (mli->mli_version) {
1409 case MLD_VERSION_1:
1410 /*
1411 * Transmit reports for this lifecycle. This
1412 * is done while not holding IF_ADDR_LOCK
1413 * since this can call
1414 * in6ifa_ifpforlinklocal() which locks
1415 * IF_ADDR_LOCK internally as well as
1416 * ip6_output() to transmit a packet.
1417 */
1418 while ((inm = SLIST_FIRST(inmh)) != NULL) {
1419 SLIST_REMOVE_HEAD(inmh, in6m_defer);
1420 (void)mld_v1_transmit_report(inm,
1421 MLD_LISTENER_REPORT);
1422 }
1423 break;
1424 case MLD_VERSION_2:
1425 mld_dispatch_queue(&qrq, 0);
1426 mld_dispatch_queue(&scq, 0);
1427 break;
1428 }
1429 NET_EPOCH_EXIT(et);
1430 }
1431
1432 out_locked:
1433 MLD_UNLOCK();
1434 IN6_MULTI_LIST_UNLOCK();
1435 }
1436
1437 /*
1438 * Update host report group timer.
1439 * Will update the global pending timer flags.
1440 */
1441 static void
mld_v1_process_group_timer(struct in6_multi_head * inmh,struct in6_multi * inm)1442 mld_v1_process_group_timer(struct in6_multi_head *inmh, struct in6_multi *inm)
1443 {
1444 int report_timer_expired;
1445
1446 IN6_MULTI_LIST_LOCK_ASSERT();
1447 MLD_LOCK_ASSERT();
1448
1449 if (inm->in6m_timer == 0) {
1450 report_timer_expired = 0;
1451 } else if (--inm->in6m_timer == 0) {
1452 report_timer_expired = 1;
1453 } else {
1454 V_current_state_timers_running6 = 1;
1455 return;
1456 }
1457
1458 switch (inm->in6m_state) {
1459 case MLD_NOT_MEMBER:
1460 case MLD_SILENT_MEMBER:
1461 case MLD_IDLE_MEMBER:
1462 case MLD_LAZY_MEMBER:
1463 case MLD_SLEEPING_MEMBER:
1464 case MLD_AWAKENING_MEMBER:
1465 break;
1466 case MLD_REPORTING_MEMBER:
1467 if (report_timer_expired) {
1468 inm->in6m_state = MLD_IDLE_MEMBER;
1469 SLIST_INSERT_HEAD(inmh, inm, in6m_defer);
1470 }
1471 break;
1472 case MLD_G_QUERY_PENDING_MEMBER:
1473 case MLD_SG_QUERY_PENDING_MEMBER:
1474 case MLD_LEAVING_MEMBER:
1475 break;
1476 }
1477 }
1478
1479 /*
1480 * Update a group's timers for MLDv2.
1481 * Will update the global pending timer flags.
1482 * Note: Unlocked read from mli.
1483 */
1484 static void
mld_v2_process_group_timers(struct in6_multi_head * inmh,struct mbufq * qrq,struct mbufq * scq,struct in6_multi * inm,const int uri_fasthz)1485 mld_v2_process_group_timers(struct in6_multi_head *inmh,
1486 struct mbufq *qrq, struct mbufq *scq,
1487 struct in6_multi *inm, const int uri_fasthz)
1488 {
1489 int query_response_timer_expired;
1490 int state_change_retransmit_timer_expired;
1491 #ifdef KTR
1492 char ip6tbuf[INET6_ADDRSTRLEN];
1493 #endif
1494
1495 IN6_MULTI_LIST_LOCK_ASSERT();
1496 MLD_LOCK_ASSERT();
1497
1498 query_response_timer_expired = 0;
1499 state_change_retransmit_timer_expired = 0;
1500
1501 /*
1502 * During a transition from compatibility mode back to MLDv2,
1503 * a group record in REPORTING state may still have its group
1504 * timer active. This is a no-op in this function; it is easier
1505 * to deal with it here than to complicate the slow-timeout path.
1506 */
1507 if (inm->in6m_timer == 0) {
1508 query_response_timer_expired = 0;
1509 } else if (--inm->in6m_timer == 0) {
1510 query_response_timer_expired = 1;
1511 } else {
1512 V_current_state_timers_running6 = 1;
1513 }
1514
1515 if (inm->in6m_sctimer == 0) {
1516 state_change_retransmit_timer_expired = 0;
1517 } else if (--inm->in6m_sctimer == 0) {
1518 state_change_retransmit_timer_expired = 1;
1519 } else {
1520 V_state_change_timers_running6 = 1;
1521 }
1522
1523 /* We are in fasttimo, so be quick about it. */
1524 if (!state_change_retransmit_timer_expired &&
1525 !query_response_timer_expired)
1526 return;
1527
1528 switch (inm->in6m_state) {
1529 case MLD_NOT_MEMBER:
1530 case MLD_SILENT_MEMBER:
1531 case MLD_SLEEPING_MEMBER:
1532 case MLD_LAZY_MEMBER:
1533 case MLD_AWAKENING_MEMBER:
1534 case MLD_IDLE_MEMBER:
1535 break;
1536 case MLD_G_QUERY_PENDING_MEMBER:
1537 case MLD_SG_QUERY_PENDING_MEMBER:
1538 /*
1539 * Respond to a previously pending Group-Specific
1540 * or Group-and-Source-Specific query by enqueueing
1541 * the appropriate Current-State report for
1542 * immediate transmission.
1543 */
1544 if (query_response_timer_expired) {
1545 int retval;
1546
1547 retval = mld_v2_enqueue_group_record(qrq, inm, 0, 1,
1548 (inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER),
1549 0);
1550 CTR2(KTR_MLD, "%s: enqueue record = %d",
1551 __func__, retval);
1552 inm->in6m_state = MLD_REPORTING_MEMBER;
1553 in6m_clear_recorded(inm);
1554 }
1555 /* FALLTHROUGH */
1556 case MLD_REPORTING_MEMBER:
1557 case MLD_LEAVING_MEMBER:
1558 if (state_change_retransmit_timer_expired) {
1559 /*
1560 * State-change retransmission timer fired.
1561 * If there are any further pending retransmissions,
1562 * set the global pending state-change flag, and
1563 * reset the timer.
1564 */
1565 if (--inm->in6m_scrv > 0) {
1566 inm->in6m_sctimer = uri_fasthz;
1567 V_state_change_timers_running6 = 1;
1568 }
1569 /*
1570 * Retransmit the previously computed state-change
1571 * report. If there are no further pending
1572 * retransmissions, the mbuf queue will be consumed.
1573 * Update T0 state to T1 as we have now sent
1574 * a state-change.
1575 */
1576 (void)mld_v2_merge_state_changes(inm, scq);
1577
1578 in6m_commit(inm);
1579 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
1580 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1581 if_name(inm->in6m_ifp));
1582
1583 /*
1584 * If we are leaving the group for good, make sure
1585 * we release MLD's reference to it.
1586 * This release must be deferred using a SLIST,
1587 * as we are called from a loop which traverses
1588 * the in_ifmultiaddr TAILQ.
1589 */
1590 if (inm->in6m_state == MLD_LEAVING_MEMBER &&
1591 inm->in6m_scrv == 0) {
1592 inm->in6m_state = MLD_NOT_MEMBER;
1593 in6m_disconnect_locked(inmh, inm);
1594 in6m_rele_locked(inmh, inm);
1595 }
1596 }
1597 break;
1598 }
1599 }
1600
1601 /*
1602 * Switch to a different version on the given interface,
1603 * as per Section 9.12.
1604 */
1605 static void
mld_set_version(struct mld_ifsoftc * mli,const int version)1606 mld_set_version(struct mld_ifsoftc *mli, const int version)
1607 {
1608 int old_version_timer;
1609
1610 MLD_LOCK_ASSERT();
1611
1612 CTR4(KTR_MLD, "%s: switching to v%d on ifp %p(%s)", __func__,
1613 version, mli->mli_ifp, if_name(mli->mli_ifp));
1614
1615 if (version == MLD_VERSION_1) {
1616 /*
1617 * Compute the "Older Version Querier Present" timer as per
1618 * Section 9.12.
1619 */
1620 old_version_timer = (mli->mli_rv * mli->mli_qi) + mli->mli_qri;
1621 old_version_timer *= PR_SLOWHZ;
1622 mli->mli_v1_timer = old_version_timer;
1623 }
1624
1625 if (mli->mli_v1_timer > 0 && mli->mli_version != MLD_VERSION_1) {
1626 mli->mli_version = MLD_VERSION_1;
1627 mld_v2_cancel_link_timers(mli);
1628 }
1629 }
1630
1631 /*
1632 * Cancel pending MLDv2 timers for the given link and all groups
1633 * joined on it; state-change, general-query, and group-query timers.
1634 */
1635 static void
mld_v2_cancel_link_timers(struct mld_ifsoftc * mli)1636 mld_v2_cancel_link_timers(struct mld_ifsoftc *mli)
1637 {
1638 struct epoch_tracker et;
1639 struct in6_multi_head inmh;
1640 struct ifmultiaddr *ifma;
1641 struct ifnet *ifp;
1642 struct in6_multi *inm;
1643
1644 CTR3(KTR_MLD, "%s: cancel v2 timers on ifp %p(%s)", __func__,
1645 mli->mli_ifp, if_name(mli->mli_ifp));
1646
1647 SLIST_INIT(&inmh);
1648 IN6_MULTI_LIST_LOCK_ASSERT();
1649 MLD_LOCK_ASSERT();
1650
1651 /*
1652 * Fast-track this potentially expensive operation
1653 * by checking all the global 'timer pending' flags.
1654 */
1655 if (!V_interface_timers_running6 &&
1656 !V_state_change_timers_running6 &&
1657 !V_current_state_timers_running6)
1658 return;
1659
1660 mli->mli_v2_timer = 0;
1661
1662 ifp = mli->mli_ifp;
1663
1664 IF_ADDR_WLOCK(ifp);
1665 NET_EPOCH_ENTER(et);
1666 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1667 inm = in6m_ifmultiaddr_get_inm(ifma);
1668 if (inm == NULL)
1669 continue;
1670 switch (inm->in6m_state) {
1671 case MLD_NOT_MEMBER:
1672 case MLD_SILENT_MEMBER:
1673 case MLD_IDLE_MEMBER:
1674 case MLD_LAZY_MEMBER:
1675 case MLD_SLEEPING_MEMBER:
1676 case MLD_AWAKENING_MEMBER:
1677 break;
1678 case MLD_LEAVING_MEMBER:
1679 /*
1680 * If we are leaving the group and switching
1681 * version, we need to release the final
1682 * reference held for issuing the INCLUDE {}.
1683 */
1684 if (inm->in6m_refcount == 1)
1685 in6m_disconnect_locked(&inmh, inm);
1686 in6m_rele_locked(&inmh, inm);
1687 /* FALLTHROUGH */
1688 case MLD_G_QUERY_PENDING_MEMBER:
1689 case MLD_SG_QUERY_PENDING_MEMBER:
1690 in6m_clear_recorded(inm);
1691 /* FALLTHROUGH */
1692 case MLD_REPORTING_MEMBER:
1693 inm->in6m_sctimer = 0;
1694 inm->in6m_timer = 0;
1695 inm->in6m_state = MLD_REPORTING_MEMBER;
1696 /*
1697 * Free any pending MLDv2 state-change records.
1698 */
1699 mbufq_drain(&inm->in6m_scq);
1700 break;
1701 }
1702 }
1703 NET_EPOCH_EXIT(et);
1704 IF_ADDR_WUNLOCK(ifp);
1705 in6m_release_list_deferred(&inmh);
1706 }
1707
1708 /*
1709 * Global slowtimo handler.
1710 * VIMAGE: Timeout handlers are expected to service all vimages.
1711 */
1712 void
mld_slowtimo(void)1713 mld_slowtimo(void)
1714 {
1715 VNET_ITERATOR_DECL(vnet_iter);
1716
1717 VNET_LIST_RLOCK_NOSLEEP();
1718 VNET_FOREACH(vnet_iter) {
1719 CURVNET_SET(vnet_iter);
1720 mld_slowtimo_vnet();
1721 CURVNET_RESTORE();
1722 }
1723 VNET_LIST_RUNLOCK_NOSLEEP();
1724 }
1725
1726 /*
1727 * Per-vnet slowtimo handler.
1728 */
1729 static void
mld_slowtimo_vnet(void)1730 mld_slowtimo_vnet(void)
1731 {
1732 struct mld_ifsoftc *mli;
1733
1734 MLD_LOCK();
1735
1736 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1737 mld_v1_process_querier_timers(mli);
1738 }
1739
1740 MLD_UNLOCK();
1741 }
1742
1743 /*
1744 * Update the Older Version Querier Present timers for a link.
1745 * See Section 9.12 of RFC 3810.
1746 */
1747 static void
mld_v1_process_querier_timers(struct mld_ifsoftc * mli)1748 mld_v1_process_querier_timers(struct mld_ifsoftc *mli)
1749 {
1750
1751 MLD_LOCK_ASSERT();
1752
1753 if (mli->mli_version != MLD_VERSION_2 && --mli->mli_v1_timer == 0) {
1754 /*
1755 * MLDv1 Querier Present timer expired; revert to MLDv2.
1756 */
1757 CTR5(KTR_MLD,
1758 "%s: transition from v%d -> v%d on %p(%s)",
1759 __func__, mli->mli_version, MLD_VERSION_2,
1760 mli->mli_ifp, if_name(mli->mli_ifp));
1761 mli->mli_version = MLD_VERSION_2;
1762 }
1763 }
1764
1765 /*
1766 * Transmit an MLDv1 report immediately.
1767 */
1768 static int
mld_v1_transmit_report(struct in6_multi * in6m,const int type)1769 mld_v1_transmit_report(struct in6_multi *in6m, const int type)
1770 {
1771 struct ifnet *ifp;
1772 struct in6_ifaddr *ia;
1773 struct ip6_hdr *ip6;
1774 struct mbuf *mh, *md;
1775 struct mld_hdr *mld;
1776
1777 NET_EPOCH_ASSERT();
1778 IN6_MULTI_LIST_LOCK_ASSERT();
1779 MLD_LOCK_ASSERT();
1780
1781 ifp = in6m->in6m_ifp;
1782 /* in process of being freed */
1783 if (ifp == NULL)
1784 return (0);
1785 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1786 /* ia may be NULL if link-local address is tentative. */
1787
1788 mh = m_gethdr(M_NOWAIT, MT_DATA);
1789 if (mh == NULL) {
1790 if (ia != NULL)
1791 ifa_free(&ia->ia_ifa);
1792 return (ENOMEM);
1793 }
1794 md = m_get(M_NOWAIT, MT_DATA);
1795 if (md == NULL) {
1796 m_free(mh);
1797 if (ia != NULL)
1798 ifa_free(&ia->ia_ifa);
1799 return (ENOMEM);
1800 }
1801 mh->m_next = md;
1802
1803 /*
1804 * FUTURE: Consider increasing alignment by ETHER_HDR_LEN, so
1805 * that ether_output() does not need to allocate another mbuf
1806 * for the header in the most common case.
1807 */
1808 M_ALIGN(mh, sizeof(struct ip6_hdr));
1809 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
1810 mh->m_len = sizeof(struct ip6_hdr);
1811
1812 ip6 = mtod(mh, struct ip6_hdr *);
1813 ip6->ip6_flow = 0;
1814 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1815 ip6->ip6_vfc |= IPV6_VERSION;
1816 ip6->ip6_nxt = IPPROTO_ICMPV6;
1817 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
1818 ip6->ip6_dst = in6m->in6m_addr;
1819
1820 md->m_len = sizeof(struct mld_hdr);
1821 mld = mtod(md, struct mld_hdr *);
1822 mld->mld_type = type;
1823 mld->mld_code = 0;
1824 mld->mld_cksum = 0;
1825 mld->mld_maxdelay = 0;
1826 mld->mld_reserved = 0;
1827 mld->mld_addr = in6m->in6m_addr;
1828 in6_clearscope(&mld->mld_addr);
1829 mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
1830 sizeof(struct ip6_hdr), sizeof(struct mld_hdr));
1831
1832 mld_save_context(mh, ifp);
1833 mh->m_flags |= M_MLDV1;
1834
1835 mld_dispatch_packet(mh);
1836
1837 if (ia != NULL)
1838 ifa_free(&ia->ia_ifa);
1839 return (0);
1840 }
1841
1842 /*
1843 * Process a state change from the upper layer for the given IPv6 group.
1844 *
1845 * Each socket holds a reference on the in_multi in its own ip_moptions.
1846 * The socket layer will have made the necessary updates to.the group
1847 * state, it is now up to MLD to issue a state change report if there
1848 * has been any change between T0 (when the last state-change was issued)
1849 * and T1 (now).
1850 *
1851 * We use the MLDv2 state machine at group level. The MLd module
1852 * however makes the decision as to which MLD protocol version to speak.
1853 * A state change *from* INCLUDE {} always means an initial join.
1854 * A state change *to* INCLUDE {} always means a final leave.
1855 *
1856 * If delay is non-zero, and the state change is an initial multicast
1857 * join, the state change report will be delayed by 'delay' ticks
1858 * in units of PR_FASTHZ if MLDv1 is active on the link; otherwise
1859 * the initial MLDv2 state change report will be delayed by whichever
1860 * is sooner, a pending state-change timer or delay itself.
1861 *
1862 * VIMAGE: curvnet should have been set by caller, as this routine
1863 * is called from the socket option handlers.
1864 */
1865 int
mld_change_state(struct in6_multi * inm,const int delay)1866 mld_change_state(struct in6_multi *inm, const int delay)
1867 {
1868 struct mld_ifsoftc *mli;
1869 struct ifnet *ifp;
1870 int error;
1871
1872 IN6_MULTI_LIST_LOCK_ASSERT();
1873
1874 error = 0;
1875
1876 /*
1877 * Check if the in6_multi has already been disconnected.
1878 */
1879 if (inm->in6m_ifp == NULL) {
1880 CTR1(KTR_MLD, "%s: inm is disconnected", __func__);
1881 return (0);
1882 }
1883
1884 /*
1885 * Try to detect if the upper layer just asked us to change state
1886 * for an interface which has now gone away.
1887 */
1888 KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
1889 ifp = inm->in6m_ifma->ifma_ifp;
1890 if (ifp == NULL)
1891 return (0);
1892 /*
1893 * Sanity check that netinet6's notion of ifp is the
1894 * same as net's.
1895 */
1896 KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
1897
1898 MLD_LOCK();
1899 mli = MLD_IFINFO(ifp);
1900 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
1901
1902 /*
1903 * If we detect a state transition to or from MCAST_UNDEFINED
1904 * for this group, then we are starting or finishing an MLD
1905 * life cycle for this group.
1906 */
1907 if (inm->in6m_st[1].iss_fmode != inm->in6m_st[0].iss_fmode) {
1908 CTR3(KTR_MLD, "%s: inm transition %d -> %d", __func__,
1909 inm->in6m_st[0].iss_fmode, inm->in6m_st[1].iss_fmode);
1910 if (inm->in6m_st[0].iss_fmode == MCAST_UNDEFINED) {
1911 CTR1(KTR_MLD, "%s: initial join", __func__);
1912 error = mld_initial_join(inm, mli, delay);
1913 goto out_locked;
1914 } else if (inm->in6m_st[1].iss_fmode == MCAST_UNDEFINED) {
1915 CTR1(KTR_MLD, "%s: final leave", __func__);
1916 mld_final_leave(inm, mli);
1917 goto out_locked;
1918 }
1919 } else {
1920 CTR1(KTR_MLD, "%s: filter set change", __func__);
1921 }
1922
1923 error = mld_handle_state_change(inm, mli);
1924
1925 out_locked:
1926 MLD_UNLOCK();
1927 return (error);
1928 }
1929
1930 /*
1931 * Perform the initial join for an MLD group.
1932 *
1933 * When joining a group:
1934 * If the group should have its MLD traffic suppressed, do nothing.
1935 * MLDv1 starts sending MLDv1 host membership reports.
1936 * MLDv2 will schedule an MLDv2 state-change report containing the
1937 * initial state of the membership.
1938 *
1939 * If the delay argument is non-zero, then we must delay sending the
1940 * initial state change for delay ticks (in units of PR_FASTHZ).
1941 */
1942 static int
mld_initial_join(struct in6_multi * inm,struct mld_ifsoftc * mli,const int delay)1943 mld_initial_join(struct in6_multi *inm, struct mld_ifsoftc *mli,
1944 const int delay)
1945 {
1946 struct epoch_tracker et;
1947 struct ifnet *ifp;
1948 struct mbufq *mq;
1949 int error, retval, syncstates;
1950 int odelay;
1951 #ifdef KTR
1952 char ip6tbuf[INET6_ADDRSTRLEN];
1953 #endif
1954
1955 CTR4(KTR_MLD, "%s: initial join %s on ifp %p(%s)",
1956 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1957 inm->in6m_ifp, if_name(inm->in6m_ifp));
1958
1959 error = 0;
1960 syncstates = 1;
1961
1962 ifp = inm->in6m_ifp;
1963
1964 IN6_MULTI_LIST_LOCK_ASSERT();
1965 MLD_LOCK_ASSERT();
1966
1967 KASSERT(mli && mli->mli_ifp == ifp, ("%s: inconsistent ifp", __func__));
1968
1969 /*
1970 * Groups joined on loopback or marked as 'not reported',
1971 * enter the MLD_SILENT_MEMBER state and
1972 * are never reported in any protocol exchanges.
1973 * All other groups enter the appropriate state machine
1974 * for the version in use on this link.
1975 * A link marked as MLIF_SILENT causes MLD to be completely
1976 * disabled for the link.
1977 */
1978 if ((ifp->if_flags & IFF_LOOPBACK) ||
1979 (mli->mli_flags & MLIF_SILENT) ||
1980 !mld_is_addr_reported(&inm->in6m_addr)) {
1981 CTR1(KTR_MLD,
1982 "%s: not kicking state machine for silent group", __func__);
1983 inm->in6m_state = MLD_SILENT_MEMBER;
1984 inm->in6m_timer = 0;
1985 } else {
1986 /*
1987 * Deal with overlapping in_multi lifecycle.
1988 * If this group was LEAVING, then make sure
1989 * we drop the reference we picked up to keep the
1990 * group around for the final INCLUDE {} enqueue.
1991 */
1992 if (mli->mli_version == MLD_VERSION_2 &&
1993 inm->in6m_state == MLD_LEAVING_MEMBER) {
1994 inm->in6m_refcount--;
1995 MPASS(inm->in6m_refcount > 0);
1996 }
1997 inm->in6m_state = MLD_REPORTING_MEMBER;
1998
1999 switch (mli->mli_version) {
2000 case MLD_VERSION_1:
2001 /*
2002 * If a delay was provided, only use it if
2003 * it is greater than the delay normally
2004 * used for an MLDv1 state change report,
2005 * and delay sending the initial MLDv1 report
2006 * by not transitioning to the IDLE state.
2007 */
2008 odelay = MLD_RANDOM_DELAY(MLD_V1_MAX_RI * PR_FASTHZ);
2009 if (delay) {
2010 inm->in6m_timer = max(delay, odelay);
2011 V_current_state_timers_running6 = 1;
2012 } else {
2013 inm->in6m_state = MLD_IDLE_MEMBER;
2014 NET_EPOCH_ENTER(et);
2015 error = mld_v1_transmit_report(inm,
2016 MLD_LISTENER_REPORT);
2017 NET_EPOCH_EXIT(et);
2018 if (error == 0) {
2019 inm->in6m_timer = odelay;
2020 V_current_state_timers_running6 = 1;
2021 }
2022 }
2023 break;
2024
2025 case MLD_VERSION_2:
2026 /*
2027 * Defer update of T0 to T1, until the first copy
2028 * of the state change has been transmitted.
2029 */
2030 syncstates = 0;
2031
2032 /*
2033 * Immediately enqueue a State-Change Report for
2034 * this interface, freeing any previous reports.
2035 * Don't kick the timers if there is nothing to do,
2036 * or if an error occurred.
2037 */
2038 mq = &inm->in6m_scq;
2039 mbufq_drain(mq);
2040 retval = mld_v2_enqueue_group_record(mq, inm, 1,
2041 0, 0, (mli->mli_flags & MLIF_USEALLOW));
2042 CTR2(KTR_MLD, "%s: enqueue record = %d",
2043 __func__, retval);
2044 if (retval <= 0) {
2045 error = retval * -1;
2046 break;
2047 }
2048
2049 /*
2050 * Schedule transmission of pending state-change
2051 * report up to RV times for this link. The timer
2052 * will fire at the next mld_fasttimo (~200ms),
2053 * giving us an opportunity to merge the reports.
2054 *
2055 * If a delay was provided to this function, only
2056 * use this delay if sooner than the existing one.
2057 */
2058 KASSERT(mli->mli_rv > 1,
2059 ("%s: invalid robustness %d", __func__,
2060 mli->mli_rv));
2061 inm->in6m_scrv = mli->mli_rv;
2062 if (delay) {
2063 if (inm->in6m_sctimer > 1) {
2064 inm->in6m_sctimer =
2065 min(inm->in6m_sctimer, delay);
2066 } else
2067 inm->in6m_sctimer = delay;
2068 } else
2069 inm->in6m_sctimer = 1;
2070 V_state_change_timers_running6 = 1;
2071
2072 error = 0;
2073 break;
2074 }
2075 }
2076
2077 /*
2078 * Only update the T0 state if state change is atomic,
2079 * i.e. we don't need to wait for a timer to fire before we
2080 * can consider the state change to have been communicated.
2081 */
2082 if (syncstates) {
2083 in6m_commit(inm);
2084 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2085 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2086 if_name(inm->in6m_ifp));
2087 }
2088
2089 return (error);
2090 }
2091
2092 /*
2093 * Issue an intermediate state change during the life-cycle.
2094 */
2095 static int
mld_handle_state_change(struct in6_multi * inm,struct mld_ifsoftc * mli)2096 mld_handle_state_change(struct in6_multi *inm, struct mld_ifsoftc *mli)
2097 {
2098 struct ifnet *ifp;
2099 int retval;
2100 #ifdef KTR
2101 char ip6tbuf[INET6_ADDRSTRLEN];
2102 #endif
2103
2104 CTR4(KTR_MLD, "%s: state change for %s on ifp %p(%s)",
2105 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2106 inm->in6m_ifp, if_name(inm->in6m_ifp));
2107
2108 ifp = inm->in6m_ifp;
2109
2110 IN6_MULTI_LIST_LOCK_ASSERT();
2111 MLD_LOCK_ASSERT();
2112
2113 KASSERT(mli && mli->mli_ifp == ifp,
2114 ("%s: inconsistent ifp", __func__));
2115
2116 if ((ifp->if_flags & IFF_LOOPBACK) ||
2117 (mli->mli_flags & MLIF_SILENT) ||
2118 !mld_is_addr_reported(&inm->in6m_addr) ||
2119 (mli->mli_version != MLD_VERSION_2)) {
2120 if (!mld_is_addr_reported(&inm->in6m_addr)) {
2121 CTR1(KTR_MLD,
2122 "%s: not kicking state machine for silent group", __func__);
2123 }
2124 CTR1(KTR_MLD, "%s: nothing to do", __func__);
2125 in6m_commit(inm);
2126 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2127 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2128 if_name(inm->in6m_ifp));
2129 return (0);
2130 }
2131
2132 mbufq_drain(&inm->in6m_scq);
2133
2134 retval = mld_v2_enqueue_group_record(&inm->in6m_scq, inm, 1, 0, 0,
2135 (mli->mli_flags & MLIF_USEALLOW));
2136 CTR2(KTR_MLD, "%s: enqueue record = %d", __func__, retval);
2137 if (retval <= 0)
2138 return (-retval);
2139
2140 /*
2141 * If record(s) were enqueued, start the state-change
2142 * report timer for this group.
2143 */
2144 inm->in6m_scrv = mli->mli_rv;
2145 inm->in6m_sctimer = 1;
2146 V_state_change_timers_running6 = 1;
2147
2148 return (0);
2149 }
2150
2151 /*
2152 * Perform the final leave for a multicast address.
2153 *
2154 * When leaving a group:
2155 * MLDv1 sends a DONE message, if and only if we are the reporter.
2156 * MLDv2 enqueues a state-change report containing a transition
2157 * to INCLUDE {} for immediate transmission.
2158 */
2159 static void
mld_final_leave(struct in6_multi * inm,struct mld_ifsoftc * mli)2160 mld_final_leave(struct in6_multi *inm, struct mld_ifsoftc *mli)
2161 {
2162 struct epoch_tracker et;
2163 #ifdef KTR
2164 char ip6tbuf[INET6_ADDRSTRLEN];
2165 #endif
2166
2167 CTR4(KTR_MLD, "%s: final leave %s on ifp %p(%s)",
2168 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2169 inm->in6m_ifp, if_name(inm->in6m_ifp));
2170
2171 IN6_MULTI_LIST_LOCK_ASSERT();
2172 MLD_LOCK_ASSERT();
2173
2174 switch (inm->in6m_state) {
2175 case MLD_NOT_MEMBER:
2176 case MLD_SILENT_MEMBER:
2177 case MLD_LEAVING_MEMBER:
2178 /* Already leaving or left; do nothing. */
2179 CTR1(KTR_MLD,
2180 "%s: not kicking state machine for silent group", __func__);
2181 break;
2182 case MLD_REPORTING_MEMBER:
2183 case MLD_IDLE_MEMBER:
2184 case MLD_G_QUERY_PENDING_MEMBER:
2185 case MLD_SG_QUERY_PENDING_MEMBER:
2186 if (mli->mli_version == MLD_VERSION_1) {
2187 #ifdef INVARIANTS
2188 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
2189 inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER)
2190 panic("%s: MLDv2 state reached, not MLDv2 mode",
2191 __func__);
2192 #endif
2193 NET_EPOCH_ENTER(et);
2194 mld_v1_transmit_report(inm, MLD_LISTENER_DONE);
2195 NET_EPOCH_EXIT(et);
2196 inm->in6m_state = MLD_NOT_MEMBER;
2197 V_current_state_timers_running6 = 1;
2198 } else if (mli->mli_version == MLD_VERSION_2) {
2199 /*
2200 * Stop group timer and all pending reports.
2201 * Immediately enqueue a state-change report
2202 * TO_IN {} to be sent on the next fast timeout,
2203 * giving us an opportunity to merge reports.
2204 */
2205 mbufq_drain(&inm->in6m_scq);
2206 inm->in6m_timer = 0;
2207 inm->in6m_scrv = mli->mli_rv;
2208 CTR4(KTR_MLD, "%s: Leaving %s/%s with %d "
2209 "pending retransmissions.", __func__,
2210 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2211 if_name(inm->in6m_ifp), inm->in6m_scrv);
2212 if (inm->in6m_scrv == 0) {
2213 inm->in6m_state = MLD_NOT_MEMBER;
2214 inm->in6m_sctimer = 0;
2215 } else {
2216 int retval;
2217
2218 in6m_acquire_locked(inm);
2219
2220 retval = mld_v2_enqueue_group_record(
2221 &inm->in6m_scq, inm, 1, 0, 0,
2222 (mli->mli_flags & MLIF_USEALLOW));
2223 KASSERT(retval != 0,
2224 ("%s: enqueue record = %d", __func__,
2225 retval));
2226
2227 inm->in6m_state = MLD_LEAVING_MEMBER;
2228 inm->in6m_sctimer = 1;
2229 V_state_change_timers_running6 = 1;
2230 }
2231 break;
2232 }
2233 break;
2234 case MLD_LAZY_MEMBER:
2235 case MLD_SLEEPING_MEMBER:
2236 case MLD_AWAKENING_MEMBER:
2237 /* Our reports are suppressed; do nothing. */
2238 break;
2239 }
2240
2241 in6m_commit(inm);
2242 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2243 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2244 if_name(inm->in6m_ifp));
2245 inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
2246 CTR3(KTR_MLD, "%s: T1 now MCAST_UNDEFINED for %p/%s",
2247 __func__, &inm->in6m_addr, if_name(inm->in6m_ifp));
2248 }
2249
2250 /*
2251 * Enqueue an MLDv2 group record to the given output queue.
2252 *
2253 * If is_state_change is zero, a current-state record is appended.
2254 * If is_state_change is non-zero, a state-change report is appended.
2255 *
2256 * If is_group_query is non-zero, an mbuf packet chain is allocated.
2257 * If is_group_query is zero, and if there is a packet with free space
2258 * at the tail of the queue, it will be appended to providing there
2259 * is enough free space.
2260 * Otherwise a new mbuf packet chain is allocated.
2261 *
2262 * If is_source_query is non-zero, each source is checked to see if
2263 * it was recorded for a Group-Source query, and will be omitted if
2264 * it is not both in-mode and recorded.
2265 *
2266 * If use_block_allow is non-zero, state change reports for initial join
2267 * and final leave, on an inclusive mode group with a source list, will be
2268 * rewritten to use the ALLOW_NEW and BLOCK_OLD record types, respectively.
2269 *
2270 * The function will attempt to allocate leading space in the packet
2271 * for the IPv6+ICMP headers to be prepended without fragmenting the chain.
2272 *
2273 * If successful the size of all data appended to the queue is returned,
2274 * otherwise an error code less than zero is returned, or zero if
2275 * no record(s) were appended.
2276 */
2277 static int
mld_v2_enqueue_group_record(struct mbufq * mq,struct in6_multi * inm,const int is_state_change,const int is_group_query,const int is_source_query,const int use_block_allow)2278 mld_v2_enqueue_group_record(struct mbufq *mq, struct in6_multi *inm,
2279 const int is_state_change, const int is_group_query,
2280 const int is_source_query, const int use_block_allow)
2281 {
2282 struct mldv2_record mr;
2283 struct mldv2_record *pmr;
2284 struct ifnet *ifp;
2285 struct ip6_msource *ims, *nims;
2286 struct mbuf *m0, *m, *md;
2287 int is_filter_list_change;
2288 int minrec0len, m0srcs, msrcs, nbytes, off;
2289 int record_has_sources;
2290 int now;
2291 int type;
2292 uint8_t mode;
2293 #ifdef KTR
2294 char ip6tbuf[INET6_ADDRSTRLEN];
2295 #endif
2296
2297 IN6_MULTI_LIST_LOCK_ASSERT();
2298
2299 ifp = inm->in6m_ifp;
2300 is_filter_list_change = 0;
2301 m = NULL;
2302 m0 = NULL;
2303 m0srcs = 0;
2304 msrcs = 0;
2305 nbytes = 0;
2306 nims = NULL;
2307 record_has_sources = 1;
2308 pmr = NULL;
2309 type = MLD_DO_NOTHING;
2310 mode = inm->in6m_st[1].iss_fmode;
2311
2312 /*
2313 * If we did not transition out of ASM mode during t0->t1,
2314 * and there are no source nodes to process, we can skip
2315 * the generation of source records.
2316 */
2317 if (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0 &&
2318 inm->in6m_nsrc == 0)
2319 record_has_sources = 0;
2320
2321 if (is_state_change) {
2322 /*
2323 * Queue a state change record.
2324 * If the mode did not change, and there are non-ASM
2325 * listeners or source filters present,
2326 * we potentially need to issue two records for the group.
2327 * If there are ASM listeners, and there was no filter
2328 * mode transition of any kind, do nothing.
2329 *
2330 * If we are transitioning to MCAST_UNDEFINED, we need
2331 * not send any sources. A transition to/from this state is
2332 * considered inclusive with some special treatment.
2333 *
2334 * If we are rewriting initial joins/leaves to use
2335 * ALLOW/BLOCK, and the group's membership is inclusive,
2336 * we need to send sources in all cases.
2337 */
2338 if (mode != inm->in6m_st[0].iss_fmode) {
2339 if (mode == MCAST_EXCLUDE) {
2340 CTR1(KTR_MLD, "%s: change to EXCLUDE",
2341 __func__);
2342 type = MLD_CHANGE_TO_EXCLUDE_MODE;
2343 } else {
2344 CTR1(KTR_MLD, "%s: change to INCLUDE",
2345 __func__);
2346 if (use_block_allow) {
2347 /*
2348 * XXX
2349 * Here we're interested in state
2350 * edges either direction between
2351 * MCAST_UNDEFINED and MCAST_INCLUDE.
2352 * Perhaps we should just check
2353 * the group state, rather than
2354 * the filter mode.
2355 */
2356 if (mode == MCAST_UNDEFINED) {
2357 type = MLD_BLOCK_OLD_SOURCES;
2358 } else {
2359 type = MLD_ALLOW_NEW_SOURCES;
2360 }
2361 } else {
2362 type = MLD_CHANGE_TO_INCLUDE_MODE;
2363 if (mode == MCAST_UNDEFINED)
2364 record_has_sources = 0;
2365 }
2366 }
2367 } else {
2368 if (record_has_sources) {
2369 is_filter_list_change = 1;
2370 } else {
2371 type = MLD_DO_NOTHING;
2372 }
2373 }
2374 } else {
2375 /*
2376 * Queue a current state record.
2377 */
2378 if (mode == MCAST_EXCLUDE) {
2379 type = MLD_MODE_IS_EXCLUDE;
2380 } else if (mode == MCAST_INCLUDE) {
2381 type = MLD_MODE_IS_INCLUDE;
2382 KASSERT(inm->in6m_st[1].iss_asm == 0,
2383 ("%s: inm %p is INCLUDE but ASM count is %d",
2384 __func__, inm, inm->in6m_st[1].iss_asm));
2385 }
2386 }
2387
2388 /*
2389 * Generate the filter list changes using a separate function.
2390 */
2391 if (is_filter_list_change)
2392 return (mld_v2_enqueue_filter_change(mq, inm));
2393
2394 if (type == MLD_DO_NOTHING) {
2395 CTR3(KTR_MLD, "%s: nothing to do for %s/%s",
2396 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2397 if_name(inm->in6m_ifp));
2398 return (0);
2399 }
2400
2401 /*
2402 * If any sources are present, we must be able to fit at least
2403 * one in the trailing space of the tail packet's mbuf,
2404 * ideally more.
2405 */
2406 minrec0len = sizeof(struct mldv2_record);
2407 if (record_has_sources)
2408 minrec0len += sizeof(struct in6_addr);
2409
2410 CTR4(KTR_MLD, "%s: queueing %s for %s/%s", __func__,
2411 mld_rec_type_to_str(type),
2412 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2413 if_name(inm->in6m_ifp));
2414
2415 /*
2416 * Check if we have a packet in the tail of the queue for this
2417 * group into which the first group record for this group will fit.
2418 * Otherwise allocate a new packet.
2419 * Always allocate leading space for IP6+RA+ICMPV6+REPORT.
2420 * Note: Group records for G/GSR query responses MUST be sent
2421 * in their own packet.
2422 */
2423 m0 = mbufq_last(mq);
2424 if (!is_group_query &&
2425 m0 != NULL &&
2426 (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <= MLD_V2_REPORT_MAXRECS) &&
2427 (m0->m_pkthdr.len + minrec0len) <
2428 (ifp->if_mtu - MLD_MTUSPACE)) {
2429 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2430 sizeof(struct mldv2_record)) /
2431 sizeof(struct in6_addr);
2432 m = m0;
2433 CTR1(KTR_MLD, "%s: use existing packet", __func__);
2434 } else {
2435 if (mbufq_full(mq)) {
2436 CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2437 return (-ENOMEM);
2438 }
2439 m = NULL;
2440 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2441 sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2442 if (!is_state_change && !is_group_query)
2443 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2444 if (m == NULL)
2445 m = m_gethdr(M_NOWAIT, MT_DATA);
2446 if (m == NULL)
2447 return (-ENOMEM);
2448
2449 mld_save_context(m, ifp);
2450
2451 CTR1(KTR_MLD, "%s: allocated first packet", __func__);
2452 }
2453
2454 /*
2455 * Append group record.
2456 * If we have sources, we don't know how many yet.
2457 */
2458 mr.mr_type = type;
2459 mr.mr_datalen = 0;
2460 mr.mr_numsrc = 0;
2461 mr.mr_addr = inm->in6m_addr;
2462 in6_clearscope(&mr.mr_addr);
2463 if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2464 if (m != m0)
2465 m_freem(m);
2466 CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2467 return (-ENOMEM);
2468 }
2469 nbytes += sizeof(struct mldv2_record);
2470
2471 /*
2472 * Append as many sources as will fit in the first packet.
2473 * If we are appending to a new packet, the chain allocation
2474 * may potentially use clusters; use m_getptr() in this case.
2475 * If we are appending to an existing packet, we need to obtain
2476 * a pointer to the group record after m_append(), in case a new
2477 * mbuf was allocated.
2478 *
2479 * Only append sources which are in-mode at t1. If we are
2480 * transitioning to MCAST_UNDEFINED state on the group, and
2481 * use_block_allow is zero, do not include source entries.
2482 * Otherwise, we need to include this source in the report.
2483 *
2484 * Only report recorded sources in our filter set when responding
2485 * to a group-source query.
2486 */
2487 if (record_has_sources) {
2488 if (m == m0) {
2489 md = m_last(m);
2490 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2491 md->m_len - nbytes);
2492 } else {
2493 md = m_getptr(m, 0, &off);
2494 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2495 off);
2496 }
2497 msrcs = 0;
2498 RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs,
2499 nims) {
2500 CTR2(KTR_MLD, "%s: visit node %s", __func__,
2501 ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2502 now = im6s_get_mode(inm, ims, 1);
2503 CTR2(KTR_MLD, "%s: node is %d", __func__, now);
2504 if ((now != mode) ||
2505 (now == mode &&
2506 (!use_block_allow && mode == MCAST_UNDEFINED))) {
2507 CTR1(KTR_MLD, "%s: skip node", __func__);
2508 continue;
2509 }
2510 if (is_source_query && ims->im6s_stp == 0) {
2511 CTR1(KTR_MLD, "%s: skip unrecorded node",
2512 __func__);
2513 continue;
2514 }
2515 CTR1(KTR_MLD, "%s: append node", __func__);
2516 if (!m_append(m, sizeof(struct in6_addr),
2517 (void *)&ims->im6s_addr)) {
2518 if (m != m0)
2519 m_freem(m);
2520 CTR1(KTR_MLD, "%s: m_append() failed.",
2521 __func__);
2522 return (-ENOMEM);
2523 }
2524 nbytes += sizeof(struct in6_addr);
2525 ++msrcs;
2526 if (msrcs == m0srcs)
2527 break;
2528 }
2529 CTR2(KTR_MLD, "%s: msrcs is %d this packet", __func__,
2530 msrcs);
2531 pmr->mr_numsrc = htons(msrcs);
2532 nbytes += (msrcs * sizeof(struct in6_addr));
2533 }
2534
2535 if (is_source_query && msrcs == 0) {
2536 CTR1(KTR_MLD, "%s: no recorded sources to report", __func__);
2537 if (m != m0)
2538 m_freem(m);
2539 return (0);
2540 }
2541
2542 /*
2543 * We are good to go with first packet.
2544 */
2545 if (m != m0) {
2546 CTR1(KTR_MLD, "%s: enqueueing first packet", __func__);
2547 m->m_pkthdr.PH_vt.vt_nrecs = 1;
2548 mbufq_enqueue(mq, m);
2549 } else
2550 m->m_pkthdr.PH_vt.vt_nrecs++;
2551
2552 /*
2553 * No further work needed if no source list in packet(s).
2554 */
2555 if (!record_has_sources)
2556 return (nbytes);
2557
2558 /*
2559 * Whilst sources remain to be announced, we need to allocate
2560 * a new packet and fill out as many sources as will fit.
2561 * Always try for a cluster first.
2562 */
2563 while (nims != NULL) {
2564 if (mbufq_full(mq)) {
2565 CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2566 return (-ENOMEM);
2567 }
2568 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2569 if (m == NULL)
2570 m = m_gethdr(M_NOWAIT, MT_DATA);
2571 if (m == NULL)
2572 return (-ENOMEM);
2573 mld_save_context(m, ifp);
2574 md = m_getptr(m, 0, &off);
2575 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) + off);
2576 CTR1(KTR_MLD, "%s: allocated next packet", __func__);
2577
2578 if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2579 if (m != m0)
2580 m_freem(m);
2581 CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2582 return (-ENOMEM);
2583 }
2584 m->m_pkthdr.PH_vt.vt_nrecs = 1;
2585 nbytes += sizeof(struct mldv2_record);
2586
2587 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2588 sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2589
2590 msrcs = 0;
2591 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2592 CTR2(KTR_MLD, "%s: visit node %s",
2593 __func__, ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2594 now = im6s_get_mode(inm, ims, 1);
2595 if ((now != mode) ||
2596 (now == mode &&
2597 (!use_block_allow && mode == MCAST_UNDEFINED))) {
2598 CTR1(KTR_MLD, "%s: skip node", __func__);
2599 continue;
2600 }
2601 if (is_source_query && ims->im6s_stp == 0) {
2602 CTR1(KTR_MLD, "%s: skip unrecorded node",
2603 __func__);
2604 continue;
2605 }
2606 CTR1(KTR_MLD, "%s: append node", __func__);
2607 if (!m_append(m, sizeof(struct in6_addr),
2608 (void *)&ims->im6s_addr)) {
2609 if (m != m0)
2610 m_freem(m);
2611 CTR1(KTR_MLD, "%s: m_append() failed.",
2612 __func__);
2613 return (-ENOMEM);
2614 }
2615 ++msrcs;
2616 if (msrcs == m0srcs)
2617 break;
2618 }
2619 pmr->mr_numsrc = htons(msrcs);
2620 nbytes += (msrcs * sizeof(struct in6_addr));
2621
2622 CTR1(KTR_MLD, "%s: enqueueing next packet", __func__);
2623 mbufq_enqueue(mq, m);
2624 }
2625
2626 return (nbytes);
2627 }
2628
2629 /*
2630 * Type used to mark record pass completion.
2631 * We exploit the fact we can cast to this easily from the
2632 * current filter modes on each ip_msource node.
2633 */
2634 typedef enum {
2635 REC_NONE = 0x00, /* MCAST_UNDEFINED */
2636 REC_ALLOW = 0x01, /* MCAST_INCLUDE */
2637 REC_BLOCK = 0x02, /* MCAST_EXCLUDE */
2638 REC_FULL = REC_ALLOW | REC_BLOCK
2639 } rectype_t;
2640
2641 /*
2642 * Enqueue an MLDv2 filter list change to the given output queue.
2643 *
2644 * Source list filter state is held in an RB-tree. When the filter list
2645 * for a group is changed without changing its mode, we need to compute
2646 * the deltas between T0 and T1 for each source in the filter set,
2647 * and enqueue the appropriate ALLOW_NEW/BLOCK_OLD records.
2648 *
2649 * As we may potentially queue two record types, and the entire R-B tree
2650 * needs to be walked at once, we break this out into its own function
2651 * so we can generate a tightly packed queue of packets.
2652 *
2653 * XXX This could be written to only use one tree walk, although that makes
2654 * serializing into the mbuf chains a bit harder. For now we do two walks
2655 * which makes things easier on us, and it may or may not be harder on
2656 * the L2 cache.
2657 *
2658 * If successful the size of all data appended to the queue is returned,
2659 * otherwise an error code less than zero is returned, or zero if
2660 * no record(s) were appended.
2661 */
2662 static int
mld_v2_enqueue_filter_change(struct mbufq * mq,struct in6_multi * inm)2663 mld_v2_enqueue_filter_change(struct mbufq *mq, struct in6_multi *inm)
2664 {
2665 static const int MINRECLEN =
2666 sizeof(struct mldv2_record) + sizeof(struct in6_addr);
2667 struct ifnet *ifp;
2668 struct mldv2_record mr;
2669 struct mldv2_record *pmr;
2670 struct ip6_msource *ims, *nims;
2671 struct mbuf *m, *m0, *md;
2672 int m0srcs, nbytes, npbytes, off, rsrcs, schanged;
2673 int nallow, nblock;
2674 uint8_t mode, now, then;
2675 rectype_t crt, drt, nrt;
2676 #ifdef KTR
2677 char ip6tbuf[INET6_ADDRSTRLEN];
2678 #endif
2679
2680 IN6_MULTI_LIST_LOCK_ASSERT();
2681
2682 if (inm->in6m_nsrc == 0 ||
2683 (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0))
2684 return (0);
2685
2686 ifp = inm->in6m_ifp; /* interface */
2687 mode = inm->in6m_st[1].iss_fmode; /* filter mode at t1 */
2688 crt = REC_NONE; /* current group record type */
2689 drt = REC_NONE; /* mask of completed group record types */
2690 nrt = REC_NONE; /* record type for current node */
2691 m0srcs = 0; /* # source which will fit in current mbuf chain */
2692 npbytes = 0; /* # of bytes appended this packet */
2693 nbytes = 0; /* # of bytes appended to group's state-change queue */
2694 rsrcs = 0; /* # sources encoded in current record */
2695 schanged = 0; /* # nodes encoded in overall filter change */
2696 nallow = 0; /* # of source entries in ALLOW_NEW */
2697 nblock = 0; /* # of source entries in BLOCK_OLD */
2698 nims = NULL; /* next tree node pointer */
2699
2700 /*
2701 * For each possible filter record mode.
2702 * The first kind of source we encounter tells us which
2703 * is the first kind of record we start appending.
2704 * If a node transitioned to UNDEFINED at t1, its mode is treated
2705 * as the inverse of the group's filter mode.
2706 */
2707 while (drt != REC_FULL) {
2708 do {
2709 m0 = mbufq_last(mq);
2710 if (m0 != NULL &&
2711 (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <=
2712 MLD_V2_REPORT_MAXRECS) &&
2713 (m0->m_pkthdr.len + MINRECLEN) <
2714 (ifp->if_mtu - MLD_MTUSPACE)) {
2715 m = m0;
2716 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2717 sizeof(struct mldv2_record)) /
2718 sizeof(struct in6_addr);
2719 CTR1(KTR_MLD,
2720 "%s: use previous packet", __func__);
2721 } else {
2722 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2723 if (m == NULL)
2724 m = m_gethdr(M_NOWAIT, MT_DATA);
2725 if (m == NULL) {
2726 CTR1(KTR_MLD,
2727 "%s: m_get*() failed", __func__);
2728 return (-ENOMEM);
2729 }
2730 m->m_pkthdr.PH_vt.vt_nrecs = 0;
2731 mld_save_context(m, ifp);
2732 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2733 sizeof(struct mldv2_record)) /
2734 sizeof(struct in6_addr);
2735 npbytes = 0;
2736 CTR1(KTR_MLD,
2737 "%s: allocated new packet", __func__);
2738 }
2739 /*
2740 * Append the MLD group record header to the
2741 * current packet's data area.
2742 * Recalculate pointer to free space for next
2743 * group record, in case m_append() allocated
2744 * a new mbuf or cluster.
2745 */
2746 memset(&mr, 0, sizeof(mr));
2747 mr.mr_addr = inm->in6m_addr;
2748 in6_clearscope(&mr.mr_addr);
2749 if (!m_append(m, sizeof(mr), (void *)&mr)) {
2750 if (m != m0)
2751 m_freem(m);
2752 CTR1(KTR_MLD,
2753 "%s: m_append() failed", __func__);
2754 return (-ENOMEM);
2755 }
2756 npbytes += sizeof(struct mldv2_record);
2757 if (m != m0) {
2758 /* new packet; offset in chain */
2759 md = m_getptr(m, npbytes -
2760 sizeof(struct mldv2_record), &off);
2761 pmr = (struct mldv2_record *)(mtod(md,
2762 uint8_t *) + off);
2763 } else {
2764 /* current packet; offset from last append */
2765 md = m_last(m);
2766 pmr = (struct mldv2_record *)(mtod(md,
2767 uint8_t *) + md->m_len -
2768 sizeof(struct mldv2_record));
2769 }
2770 /*
2771 * Begin walking the tree for this record type
2772 * pass, or continue from where we left off
2773 * previously if we had to allocate a new packet.
2774 * Only report deltas in-mode at t1.
2775 * We need not report included sources as allowed
2776 * if we are in inclusive mode on the group,
2777 * however the converse is not true.
2778 */
2779 rsrcs = 0;
2780 if (nims == NULL) {
2781 nims = RB_MIN(ip6_msource_tree,
2782 &inm->in6m_srcs);
2783 }
2784 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2785 CTR2(KTR_MLD, "%s: visit node %s", __func__,
2786 ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2787 now = im6s_get_mode(inm, ims, 1);
2788 then = im6s_get_mode(inm, ims, 0);
2789 CTR3(KTR_MLD, "%s: mode: t0 %d, t1 %d",
2790 __func__, then, now);
2791 if (now == then) {
2792 CTR1(KTR_MLD,
2793 "%s: skip unchanged", __func__);
2794 continue;
2795 }
2796 if (mode == MCAST_EXCLUDE &&
2797 now == MCAST_INCLUDE) {
2798 CTR1(KTR_MLD,
2799 "%s: skip IN src on EX group",
2800 __func__);
2801 continue;
2802 }
2803 nrt = (rectype_t)now;
2804 if (nrt == REC_NONE)
2805 nrt = (rectype_t)(~mode & REC_FULL);
2806 if (schanged++ == 0) {
2807 crt = nrt;
2808 } else if (crt != nrt)
2809 continue;
2810 if (!m_append(m, sizeof(struct in6_addr),
2811 (void *)&ims->im6s_addr)) {
2812 if (m != m0)
2813 m_freem(m);
2814 CTR1(KTR_MLD,
2815 "%s: m_append() failed", __func__);
2816 return (-ENOMEM);
2817 }
2818 nallow += !!(crt == REC_ALLOW);
2819 nblock += !!(crt == REC_BLOCK);
2820 if (++rsrcs == m0srcs)
2821 break;
2822 }
2823 /*
2824 * If we did not append any tree nodes on this
2825 * pass, back out of allocations.
2826 */
2827 if (rsrcs == 0) {
2828 npbytes -= sizeof(struct mldv2_record);
2829 if (m != m0) {
2830 CTR1(KTR_MLD,
2831 "%s: m_free(m)", __func__);
2832 m_freem(m);
2833 } else {
2834 CTR1(KTR_MLD,
2835 "%s: m_adj(m, -mr)", __func__);
2836 m_adj(m, -((int)sizeof(
2837 struct mldv2_record)));
2838 }
2839 continue;
2840 }
2841 npbytes += (rsrcs * sizeof(struct in6_addr));
2842 if (crt == REC_ALLOW)
2843 pmr->mr_type = MLD_ALLOW_NEW_SOURCES;
2844 else if (crt == REC_BLOCK)
2845 pmr->mr_type = MLD_BLOCK_OLD_SOURCES;
2846 pmr->mr_numsrc = htons(rsrcs);
2847 /*
2848 * Count the new group record, and enqueue this
2849 * packet if it wasn't already queued.
2850 */
2851 m->m_pkthdr.PH_vt.vt_nrecs++;
2852 if (m != m0)
2853 mbufq_enqueue(mq, m);
2854 nbytes += npbytes;
2855 } while (nims != NULL);
2856 drt |= crt;
2857 crt = (~crt & REC_FULL);
2858 }
2859
2860 CTR3(KTR_MLD, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
2861 nallow, nblock);
2862
2863 return (nbytes);
2864 }
2865
2866 static int
mld_v2_merge_state_changes(struct in6_multi * inm,struct mbufq * scq)2867 mld_v2_merge_state_changes(struct in6_multi *inm, struct mbufq *scq)
2868 {
2869 struct mbufq *gq;
2870 struct mbuf *m; /* pending state-change */
2871 struct mbuf *m0; /* copy of pending state-change */
2872 struct mbuf *mt; /* last state-change in packet */
2873 int docopy, domerge;
2874 u_int recslen;
2875
2876 docopy = 0;
2877 domerge = 0;
2878 recslen = 0;
2879
2880 IN6_MULTI_LIST_LOCK_ASSERT();
2881 MLD_LOCK_ASSERT();
2882
2883 /*
2884 * If there are further pending retransmissions, make a writable
2885 * copy of each queued state-change message before merging.
2886 */
2887 if (inm->in6m_scrv > 0)
2888 docopy = 1;
2889
2890 gq = &inm->in6m_scq;
2891 #ifdef KTR
2892 if (mbufq_first(gq) == NULL) {
2893 CTR2(KTR_MLD, "%s: WARNING: queue for inm %p is empty",
2894 __func__, inm);
2895 }
2896 #endif
2897
2898 m = mbufq_first(gq);
2899 while (m != NULL) {
2900 /*
2901 * Only merge the report into the current packet if
2902 * there is sufficient space to do so; an MLDv2 report
2903 * packet may only contain 65,535 group records.
2904 * Always use a simple mbuf chain concatentation to do this,
2905 * as large state changes for single groups may have
2906 * allocated clusters.
2907 */
2908 domerge = 0;
2909 mt = mbufq_last(scq);
2910 if (mt != NULL) {
2911 recslen = m_length(m, NULL);
2912
2913 if ((mt->m_pkthdr.PH_vt.vt_nrecs +
2914 m->m_pkthdr.PH_vt.vt_nrecs <=
2915 MLD_V2_REPORT_MAXRECS) &&
2916 (mt->m_pkthdr.len + recslen <=
2917 (inm->in6m_ifp->if_mtu - MLD_MTUSPACE)))
2918 domerge = 1;
2919 }
2920
2921 if (!domerge && mbufq_full(gq)) {
2922 CTR2(KTR_MLD,
2923 "%s: outbound queue full, skipping whole packet %p",
2924 __func__, m);
2925 mt = m->m_nextpkt;
2926 if (!docopy)
2927 m_freem(m);
2928 m = mt;
2929 continue;
2930 }
2931
2932 if (!docopy) {
2933 CTR2(KTR_MLD, "%s: dequeueing %p", __func__, m);
2934 m0 = mbufq_dequeue(gq);
2935 m = m0->m_nextpkt;
2936 } else {
2937 CTR2(KTR_MLD, "%s: copying %p", __func__, m);
2938 m0 = m_dup(m, M_NOWAIT);
2939 if (m0 == NULL)
2940 return (ENOMEM);
2941 m0->m_nextpkt = NULL;
2942 m = m->m_nextpkt;
2943 }
2944
2945 if (!domerge) {
2946 CTR3(KTR_MLD, "%s: queueing %p to scq %p)",
2947 __func__, m0, scq);
2948 mbufq_enqueue(scq, m0);
2949 } else {
2950 struct mbuf *mtl; /* last mbuf of packet mt */
2951
2952 CTR3(KTR_MLD, "%s: merging %p with ifscq tail %p)",
2953 __func__, m0, mt);
2954
2955 mtl = m_last(mt);
2956 m0->m_flags &= ~M_PKTHDR;
2957 mt->m_pkthdr.len += recslen;
2958 mt->m_pkthdr.PH_vt.vt_nrecs +=
2959 m0->m_pkthdr.PH_vt.vt_nrecs;
2960
2961 mtl->m_next = m0;
2962 }
2963 }
2964
2965 return (0);
2966 }
2967
2968 /*
2969 * Respond to a pending MLDv2 General Query.
2970 */
2971 static void
mld_v2_dispatch_general_query(struct mld_ifsoftc * mli)2972 mld_v2_dispatch_general_query(struct mld_ifsoftc *mli)
2973 {
2974 struct ifmultiaddr *ifma;
2975 struct ifnet *ifp;
2976 struct in6_multi *inm;
2977 int retval;
2978
2979 NET_EPOCH_ASSERT();
2980 IN6_MULTI_LIST_LOCK_ASSERT();
2981 MLD_LOCK_ASSERT();
2982
2983 KASSERT(mli->mli_version == MLD_VERSION_2,
2984 ("%s: called when version %d", __func__, mli->mli_version));
2985
2986 /*
2987 * Check that there are some packets queued. If so, send them first.
2988 * For large number of groups the reply to general query can take
2989 * many packets, we should finish sending them before starting of
2990 * queuing the new reply.
2991 */
2992 if (!mbufq_empty(&mli->mli_gq))
2993 goto send;
2994
2995 ifp = mli->mli_ifp;
2996
2997 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
2998 inm = in6m_ifmultiaddr_get_inm(ifma);
2999 if (inm == NULL)
3000 continue;
3001 KASSERT(ifp == inm->in6m_ifp,
3002 ("%s: inconsistent ifp", __func__));
3003
3004 switch (inm->in6m_state) {
3005 case MLD_NOT_MEMBER:
3006 case MLD_SILENT_MEMBER:
3007 break;
3008 case MLD_REPORTING_MEMBER:
3009 case MLD_IDLE_MEMBER:
3010 case MLD_LAZY_MEMBER:
3011 case MLD_SLEEPING_MEMBER:
3012 case MLD_AWAKENING_MEMBER:
3013 inm->in6m_state = MLD_REPORTING_MEMBER;
3014 retval = mld_v2_enqueue_group_record(&mli->mli_gq,
3015 inm, 0, 0, 0, 0);
3016 CTR2(KTR_MLD, "%s: enqueue record = %d",
3017 __func__, retval);
3018 break;
3019 case MLD_G_QUERY_PENDING_MEMBER:
3020 case MLD_SG_QUERY_PENDING_MEMBER:
3021 case MLD_LEAVING_MEMBER:
3022 break;
3023 }
3024 }
3025
3026 send:
3027 mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST);
3028
3029 /*
3030 * Slew transmission of bursts over 500ms intervals.
3031 */
3032 if (mbufq_first(&mli->mli_gq) != NULL) {
3033 mli->mli_v2_timer = 1 + MLD_RANDOM_DELAY(
3034 MLD_RESPONSE_BURST_INTERVAL);
3035 V_interface_timers_running6 = 1;
3036 }
3037 }
3038
3039 /*
3040 * Transmit the next pending message in the output queue.
3041 *
3042 * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
3043 * MRT: Nothing needs to be done, as MLD traffic is always local to
3044 * a link and uses a link-scope multicast address.
3045 */
3046 static void
mld_dispatch_packet(struct mbuf * m)3047 mld_dispatch_packet(struct mbuf *m)
3048 {
3049 struct ip6_moptions im6o;
3050 struct ifnet *ifp;
3051 struct ifnet *oifp;
3052 struct mbuf *m0;
3053 struct mbuf *md;
3054 struct ip6_hdr *ip6;
3055 struct mld_hdr *mld;
3056 int error;
3057 int off;
3058 int type;
3059 uint32_t ifindex;
3060
3061 CTR2(KTR_MLD, "%s: transmit %p", __func__, m);
3062 NET_EPOCH_ASSERT();
3063
3064 /*
3065 * Set VNET image pointer from enqueued mbuf chain
3066 * before doing anything else. Whilst we use interface
3067 * indexes to guard against interface detach, they are
3068 * unique to each VIMAGE and must be retrieved.
3069 */
3070 ifindex = mld_restore_context(m);
3071
3072 /*
3073 * Check if the ifnet still exists. This limits the scope of
3074 * any race in the absence of a global ifp lock for low cost
3075 * (an array lookup).
3076 */
3077 ifp = ifnet_byindex(ifindex);
3078 if (ifp == NULL) {
3079 CTR3(KTR_MLD, "%s: dropped %p as ifindex %u went away.",
3080 __func__, m, ifindex);
3081 m_freem(m);
3082 IP6STAT_INC(ip6s_noroute);
3083 goto out;
3084 }
3085
3086 im6o.im6o_multicast_hlim = 1;
3087 im6o.im6o_multicast_loop = (V_ip6_mrouter != NULL);
3088 im6o.im6o_multicast_ifp = ifp;
3089
3090 if (m->m_flags & M_MLDV1) {
3091 m0 = m;
3092 } else {
3093 m0 = mld_v2_encap_report(ifp, m);
3094 if (m0 == NULL) {
3095 CTR2(KTR_MLD, "%s: dropped %p", __func__, m);
3096 IP6STAT_INC(ip6s_odropped);
3097 goto out;
3098 }
3099 }
3100
3101 mld_scrub_context(m0);
3102 m_clrprotoflags(m);
3103 m0->m_pkthdr.rcvif = V_loif;
3104
3105 ip6 = mtod(m0, struct ip6_hdr *);
3106 #if 0
3107 (void)in6_setscope(&ip6->ip6_dst, ifp, NULL); /* XXX LOR */
3108 #else
3109 /*
3110 * XXX XXX Break some KPI rules to prevent an LOR which would
3111 * occur if we called in6_setscope() at transmission.
3112 * See comments at top of file.
3113 */
3114 MLD_EMBEDSCOPE(&ip6->ip6_dst, ifp->if_index);
3115 #endif
3116
3117 /*
3118 * Retrieve the ICMPv6 type before handoff to ip6_output(),
3119 * so we can bump the stats.
3120 */
3121 md = m_getptr(m0, sizeof(struct ip6_hdr), &off);
3122 mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off);
3123 type = mld->mld_type;
3124
3125 oifp = NULL;
3126 error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o,
3127 &oifp, NULL);
3128 if (error) {
3129 CTR3(KTR_MLD, "%s: ip6_output(%p) = %d", __func__, m0, error);
3130 goto out;
3131 }
3132 ICMP6STAT_INC(icp6s_outhist[type]);
3133 if (oifp != NULL) {
3134 icmp6_ifstat_inc(oifp, ifs6_out_msg);
3135 switch (type) {
3136 case MLD_LISTENER_REPORT:
3137 case MLDV2_LISTENER_REPORT:
3138 icmp6_ifstat_inc(oifp, ifs6_out_mldreport);
3139 break;
3140 case MLD_LISTENER_DONE:
3141 icmp6_ifstat_inc(oifp, ifs6_out_mlddone);
3142 break;
3143 }
3144 }
3145 out:
3146 return;
3147 }
3148
3149 /*
3150 * Encapsulate an MLDv2 report.
3151 *
3152 * KAME IPv6 requires that hop-by-hop options be passed separately,
3153 * and that the IPv6 header be prepended in a separate mbuf.
3154 *
3155 * Returns a pointer to the new mbuf chain head, or NULL if the
3156 * allocation failed.
3157 */
3158 static struct mbuf *
mld_v2_encap_report(struct ifnet * ifp,struct mbuf * m)3159 mld_v2_encap_report(struct ifnet *ifp, struct mbuf *m)
3160 {
3161 struct mbuf *mh;
3162 struct mldv2_report *mld;
3163 struct ip6_hdr *ip6;
3164 struct in6_ifaddr *ia;
3165 int mldreclen;
3166
3167 KASSERT(ifp != NULL, ("%s: null ifp", __func__));
3168 KASSERT((m->m_flags & M_PKTHDR),
3169 ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
3170
3171 /*
3172 * RFC3590: OK to send as :: or tentative during DAD.
3173 */
3174 NET_EPOCH_ASSERT();
3175 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
3176 if (ia == NULL)
3177 CTR1(KTR_MLD, "%s: warning: ia is NULL", __func__);
3178
3179 mh = m_gethdr(M_NOWAIT, MT_DATA);
3180 if (mh == NULL) {
3181 if (ia != NULL)
3182 ifa_free(&ia->ia_ifa);
3183 m_freem(m);
3184 return (NULL);
3185 }
3186 M_ALIGN(mh, sizeof(struct ip6_hdr) + sizeof(struct mldv2_report));
3187
3188 mldreclen = m_length(m, NULL);
3189 CTR2(KTR_MLD, "%s: mldreclen is %d", __func__, mldreclen);
3190
3191 mh->m_len = sizeof(struct ip6_hdr) + sizeof(struct mldv2_report);
3192 mh->m_pkthdr.len = sizeof(struct ip6_hdr) +
3193 sizeof(struct mldv2_report) + mldreclen;
3194
3195 ip6 = mtod(mh, struct ip6_hdr *);
3196 ip6->ip6_flow = 0;
3197 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
3198 ip6->ip6_vfc |= IPV6_VERSION;
3199 ip6->ip6_nxt = IPPROTO_ICMPV6;
3200 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
3201 if (ia != NULL)
3202 ifa_free(&ia->ia_ifa);
3203 ip6->ip6_dst = in6addr_linklocal_allv2routers;
3204 /* scope ID will be set in netisr */
3205
3206 mld = (struct mldv2_report *)(ip6 + 1);
3207 mld->mld_type = MLDV2_LISTENER_REPORT;
3208 mld->mld_code = 0;
3209 mld->mld_cksum = 0;
3210 mld->mld_v2_reserved = 0;
3211 mld->mld_v2_numrecs = htons(m->m_pkthdr.PH_vt.vt_nrecs);
3212 m->m_pkthdr.PH_vt.vt_nrecs = 0;
3213
3214 mh->m_next = m;
3215 mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
3216 sizeof(struct ip6_hdr), sizeof(struct mldv2_report) + mldreclen);
3217 return (mh);
3218 }
3219
3220 #ifdef KTR
3221 static char *
mld_rec_type_to_str(const int type)3222 mld_rec_type_to_str(const int type)
3223 {
3224
3225 switch (type) {
3226 case MLD_CHANGE_TO_EXCLUDE_MODE:
3227 return "TO_EX";
3228 break;
3229 case MLD_CHANGE_TO_INCLUDE_MODE:
3230 return "TO_IN";
3231 break;
3232 case MLD_MODE_IS_EXCLUDE:
3233 return "MODE_EX";
3234 break;
3235 case MLD_MODE_IS_INCLUDE:
3236 return "MODE_IN";
3237 break;
3238 case MLD_ALLOW_NEW_SOURCES:
3239 return "ALLOW_NEW";
3240 break;
3241 case MLD_BLOCK_OLD_SOURCES:
3242 return "BLOCK_OLD";
3243 break;
3244 default:
3245 break;
3246 }
3247 return "unknown";
3248 }
3249 #endif
3250
3251 static void
mld_init(void * unused __unused)3252 mld_init(void *unused __unused)
3253 {
3254
3255 CTR1(KTR_MLD, "%s: initializing", __func__);
3256 MLD_LOCK_INIT();
3257
3258 ip6_initpktopts(&mld_po);
3259 mld_po.ip6po_hlim = 1;
3260 mld_po.ip6po_hbh = &mld_ra.hbh;
3261 mld_po.ip6po_prefer_tempaddr = IP6PO_TEMPADDR_NOTPREFER;
3262 mld_po.ip6po_flags = IP6PO_DONTFRAG;
3263 }
3264 SYSINIT(mld_init, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_init, NULL);
3265
3266 static void
mld_uninit(void * unused __unused)3267 mld_uninit(void *unused __unused)
3268 {
3269
3270 CTR1(KTR_MLD, "%s: tearing down", __func__);
3271 MLD_LOCK_DESTROY();
3272 }
3273 SYSUNINIT(mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_uninit, NULL);
3274
3275 static void
vnet_mld_init(const void * unused __unused)3276 vnet_mld_init(const void *unused __unused)
3277 {
3278
3279 CTR1(KTR_MLD, "%s: initializing", __func__);
3280
3281 LIST_INIT(&V_mli_head);
3282 }
3283 VNET_SYSINIT(vnet_mld_init, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_init,
3284 NULL);
3285
3286 static void
vnet_mld_uninit(const void * unused __unused)3287 vnet_mld_uninit(const void *unused __unused)
3288 {
3289
3290 /* This can happen if we shutdown the network stack. */
3291 CTR1(KTR_MLD, "%s: tearing down", __func__);
3292 }
3293 VNET_SYSUNINIT(vnet_mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_uninit,
3294 NULL);
3295
3296 static int
mld_modevent(module_t mod,int type,void * unused __unused)3297 mld_modevent(module_t mod, int type, void *unused __unused)
3298 {
3299
3300 switch (type) {
3301 case MOD_LOAD:
3302 case MOD_UNLOAD:
3303 break;
3304 default:
3305 return (EOPNOTSUPP);
3306 }
3307 return (0);
3308 }
3309
3310 static moduledata_t mld_mod = {
3311 "mld",
3312 mld_modevent,
3313 0
3314 };
3315 DECLARE_MODULE(mld, mld_mod, SI_SUB_PROTO_MC, SI_ORDER_ANY);
3316