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
66 #include <sys/cdefs.h>
67 #include "opt_inet.h"
68 #include "opt_inet6.h"
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/mbuf.h>
73 #include <sys/socket.h>
74 #include <sys/sysctl.h>
75 #include <sys/kernel.h>
76 #include <sys/callout.h>
77 #include <sys/malloc.h>
78 #include <sys/module.h>
79 #include <sys/ktr.h>
80
81 #include <net/if.h>
82 #include <net/if_var.h>
83 #include <net/if_private.h>
84 #include <net/route.h>
85 #include <net/vnet.h>
86
87 #include <netinet/in.h>
88 #include <netinet/in_var.h>
89 #include <netinet6/in6_var.h>
90 #include <netinet/ip6.h>
91 #include <netinet6/ip6_var.h>
92 #include <netinet6/scope6_var.h>
93 #include <netinet/icmp6.h>
94 #include <netinet6/mld6.h>
95 #include <netinet6/mld6_var.h>
96
97 #include <security/mac/mac_framework.h>
98
99 #ifndef KTR_MLD
100 #define KTR_MLD KTR_INET6
101 #endif
102
103 static void mli_delete_locked(struct ifnet *);
104 static void mld_dispatch_packet(struct mbuf *);
105 static void mld_dispatch_queue(struct mbufq *, int);
106 static void mld_final_leave(struct in6_multi *, struct mld_ifsoftc *);
107 static void mld_fasttimo_vnet(struct in6_multi_head *inmh);
108 static int mld_handle_state_change(struct in6_multi *,
109 struct mld_ifsoftc *);
110 static int mld_initial_join(struct in6_multi *, struct mld_ifsoftc *,
111 const int);
112 #ifdef KTR
113 static char * mld_rec_type_to_str(const int);
114 #endif
115 static void mld_set_version(struct mld_ifsoftc *, const int);
116 static void mld_slowtimo_vnet(void);
117 static int mld_v1_input_query(struct ifnet *, const struct ip6_hdr *,
118 /*const*/ struct mld_hdr *);
119 static int mld_v1_input_report(struct ifnet *, const struct ip6_hdr *,
120 /*const*/ struct mld_hdr *);
121 static void mld_v1_process_group_timer(struct in6_multi_head *,
122 struct in6_multi *);
123 static void mld_v1_process_querier_timers(struct mld_ifsoftc *);
124 static int mld_v1_transmit_report(struct in6_multi *, const int);
125 static void mld_v1_update_group(struct in6_multi *, const int);
126 static void mld_v2_cancel_link_timers(struct mld_ifsoftc *);
127 static void mld_v2_dispatch_general_query(struct mld_ifsoftc *);
128 static struct mbuf *
129 mld_v2_encap_report(struct ifnet *, struct mbuf *);
130 static int mld_v2_enqueue_filter_change(struct mbufq *,
131 struct in6_multi *);
132 static int mld_v2_enqueue_group_record(struct mbufq *,
133 struct in6_multi *, const int, const int, const int,
134 const int);
135 static int mld_v2_input_query(struct ifnet *, const struct ip6_hdr *,
136 struct mbuf *, struct mldv2_query *, const int, const int);
137 static int mld_v2_merge_state_changes(struct in6_multi *,
138 struct mbufq *);
139 static void mld_v2_process_group_timers(struct in6_multi_head *,
140 struct mbufq *, struct mbufq *,
141 struct in6_multi *, const int);
142 static int mld_v2_process_group_query(struct in6_multi *,
143 struct mld_ifsoftc *mli, int, struct mbuf *,
144 struct mldv2_query *, const int);
145 static int sysctl_mld_gsr(SYSCTL_HANDLER_ARGS);
146 static int sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS);
147
148 /*
149 * Normative references: RFC 2710, RFC 3590, RFC 3810.
150 *
151 * Locking:
152 * * The MLD subsystem lock ends up being system-wide for the moment,
153 * but could be per-VIMAGE later on.
154 * * The permitted lock order is: IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
155 * Any may be taken independently; if any are held at the same
156 * time, the above lock order must be followed.
157 * * IN6_MULTI_LOCK covers in_multi.
158 * * MLD_LOCK covers per-link state and any global variables in this file.
159 * * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
160 * per-link state iterators.
161 *
162 * XXX LOR PREVENTION
163 * A special case for IPv6 is the in6_setscope() routine. ip6_output()
164 * will not accept an ifp; it wants an embedded scope ID, unlike
165 * ip_output(), which happily takes the ifp given to it. The embedded
166 * scope ID is only used by MLD to select the outgoing interface.
167 *
168 * During interface attach and detach, MLD will take MLD_LOCK *after*
169 * the IF_AFDATA_LOCK.
170 * As in6_setscope() takes IF_AFDATA_LOCK then SCOPE_LOCK, we can't call
171 * it with MLD_LOCK held without triggering an LOR. A netisr with indirect
172 * dispatch could work around this, but we'd rather not do that, as it
173 * can introduce other races.
174 *
175 * As such, we exploit the fact that the scope ID is just the interface
176 * index, and embed it in the IPv6 destination address accordingly.
177 * This is potentially NOT VALID for MLDv1 reports, as they
178 * are always sent to the multicast group itself; as MLDv2
179 * reports are always sent to ff02::16, this is not an issue
180 * when MLDv2 is in use.
181 *
182 * This does not however eliminate the LOR when ip6_output() itself
183 * calls in6_setscope() internally whilst MLD_LOCK is held. This will
184 * trigger a LOR warning in WITNESS when the ifnet is detached.
185 *
186 * The right answer is probably to make IF_AFDATA_LOCK an rwlock, given
187 * how it's used across the network stack. Here we're simply exploiting
188 * the fact that MLD runs at a similar layer in the stack to scope6.c.
189 *
190 * VIMAGE:
191 * * Each in6_multi corresponds to an ifp, and each ifp corresponds
192 * to a vnet in ifp->if_vnet.
193 */
194 static struct mtx mld_mtx;
195 static MALLOC_DEFINE(M_MLD, "mld", "mld state");
196
197 #define MLD_EMBEDSCOPE(pin6, zoneid) \
198 if (IN6_IS_SCOPE_LINKLOCAL(pin6) || \
199 IN6_IS_ADDR_MC_INTFACELOCAL(pin6)) \
200 (pin6)->s6_addr16[1] = htons((zoneid) & 0xFFFF) \
201
202 /*
203 * VIMAGE-wide globals.
204 */
205 VNET_DEFINE_STATIC(struct timeval, mld_gsrdelay) = {10, 0};
206 VNET_DEFINE_STATIC(LIST_HEAD(, mld_ifsoftc), mli_head);
207 VNET_DEFINE_STATIC(int, interface_timers_running6);
208 VNET_DEFINE_STATIC(int, state_change_timers_running6);
209 VNET_DEFINE_STATIC(int, current_state_timers_running6);
210
211 #define V_mld_gsrdelay VNET(mld_gsrdelay)
212 #define V_mli_head VNET(mli_head)
213 #define V_interface_timers_running6 VNET(interface_timers_running6)
214 #define V_state_change_timers_running6 VNET(state_change_timers_running6)
215 #define V_current_state_timers_running6 VNET(current_state_timers_running6)
216
217 SYSCTL_DECL(_net_inet6); /* Note: Not in any common header. */
218
219 SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
220 "IPv6 Multicast Listener Discovery");
221
222 /*
223 * Virtualized sysctls.
224 */
225 SYSCTL_PROC(_net_inet6_mld, OID_AUTO, gsrdelay,
226 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
227 &VNET_NAME(mld_gsrdelay.tv_sec), 0, sysctl_mld_gsr, "I",
228 "Rate limit for MLDv2 Group-and-Source queries in seconds");
229
230 /*
231 * Non-virtualized sysctls.
232 */
233 static SYSCTL_NODE(_net_inet6_mld, OID_AUTO, ifinfo,
234 CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_mld_ifinfo,
235 "Per-interface MLDv2 state");
236
237 static int mld_v1enable = 1;
238 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v1enable, CTLFLAG_RWTUN,
239 &mld_v1enable, 0, "Enable fallback to MLDv1");
240
241 static int mld_v2enable = 1;
242 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v2enable, CTLFLAG_RWTUN,
243 &mld_v2enable, 0, "Enable MLDv2");
244
245 static int mld_use_allow = 1;
246 SYSCTL_INT(_net_inet6_mld, OID_AUTO, use_allow, CTLFLAG_RWTUN,
247 &mld_use_allow, 0, "Use ALLOW/BLOCK for RFC 4604 SSM joins/leaves");
248
249 /*
250 * Packed Router Alert option structure declaration.
251 */
252 struct mld_raopt {
253 struct ip6_hbh hbh;
254 struct ip6_opt pad;
255 struct ip6_opt_router ra;
256 } __packed;
257
258 /*
259 * Router Alert hop-by-hop option header.
260 */
261 static struct mld_raopt mld_ra = {
262 .hbh = { 0, 0 },
263 .pad = { .ip6o_type = IP6OPT_PADN, 0 },
264 .ra = {
265 .ip6or_type = IP6OPT_ROUTER_ALERT,
266 .ip6or_len = IP6OPT_RTALERT_LEN - 2,
267 .ip6or_value[0] = ((IP6OPT_RTALERT_MLD >> 8) & 0xFF),
268 .ip6or_value[1] = (IP6OPT_RTALERT_MLD & 0xFF)
269 }
270 };
271 static struct ip6_pktopts mld_po;
272
273 static __inline void
mld_save_context(struct mbuf * m,struct ifnet * ifp)274 mld_save_context(struct mbuf *m, struct ifnet *ifp)
275 {
276
277 #ifdef VIMAGE
278 m->m_pkthdr.PH_loc.ptr = ifp->if_vnet;
279 #endif /* VIMAGE */
280 m->m_pkthdr.rcvif = ifp;
281 m->m_pkthdr.flowid = ifp->if_index;
282 }
283
284 static __inline void
mld_scrub_context(struct mbuf * m)285 mld_scrub_context(struct mbuf *m)
286 {
287
288 m->m_pkthdr.PH_loc.ptr = NULL;
289 m->m_pkthdr.flowid = 0;
290 }
291
292 /*
293 * Restore context from a queued output chain.
294 * Return saved ifindex.
295 *
296 * VIMAGE: The assertion is there to make sure that we
297 * actually called CURVNET_SET() with what's in the mbuf chain.
298 */
299 static __inline uint32_t
mld_restore_context(struct mbuf * m)300 mld_restore_context(struct mbuf *m)
301 {
302
303 #if defined(VIMAGE) && defined(INVARIANTS)
304 KASSERT(curvnet == m->m_pkthdr.PH_loc.ptr,
305 ("%s: called when curvnet was not restored: cuvnet %p m ptr %p",
306 __func__, curvnet, m->m_pkthdr.PH_loc.ptr));
307 #endif
308 return (m->m_pkthdr.flowid);
309 }
310
311 /*
312 * Retrieve or set threshold between group-source queries in seconds.
313 *
314 * VIMAGE: Assume curvnet set by caller.
315 * SMPng: NOTE: Serialized by MLD lock.
316 */
317 static int
sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)318 sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
319 {
320 int error;
321 int i;
322
323 error = sysctl_wire_old_buffer(req, sizeof(int));
324 if (error)
325 return (error);
326
327 MLD_LOCK();
328
329 i = V_mld_gsrdelay.tv_sec;
330
331 error = sysctl_handle_int(oidp, &i, 0, req);
332 if (error || !req->newptr)
333 goto out_locked;
334
335 if (i < -1 || i >= 60) {
336 error = EINVAL;
337 goto out_locked;
338 }
339
340 CTR2(KTR_MLD, "change mld_gsrdelay from %d to %d",
341 V_mld_gsrdelay.tv_sec, i);
342 V_mld_gsrdelay.tv_sec = i;
343
344 out_locked:
345 MLD_UNLOCK();
346 return (error);
347 }
348
349 /*
350 * Expose struct mld_ifsoftc to userland, keyed by ifindex.
351 * For use by ifmcstat(8).
352 *
353 * VIMAGE: Assume curvnet set by caller. The node handler itself
354 * is not directly virtualized.
355 */
356 static int
sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)357 sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
358 {
359 struct epoch_tracker et;
360 int *name;
361 int error;
362 u_int namelen;
363 struct ifnet *ifp;
364 struct mld_ifsoftc *mli;
365
366 name = (int *)arg1;
367 namelen = arg2;
368
369 if (req->newptr != NULL)
370 return (EPERM);
371
372 if (namelen != 1)
373 return (EINVAL);
374
375 error = sysctl_wire_old_buffer(req, sizeof(struct mld_ifinfo));
376 if (error)
377 return (error);
378
379 IN6_MULTI_LOCK();
380 IN6_MULTI_LIST_LOCK();
381 MLD_LOCK();
382 NET_EPOCH_ENTER(et);
383
384 error = ENOENT;
385 ifp = ifnet_byindex(name[0]);
386 if (ifp == NULL)
387 goto out_locked;
388
389 LIST_FOREACH(mli, &V_mli_head, mli_link) {
390 if (ifp == mli->mli_ifp) {
391 struct mld_ifinfo info;
392
393 info.mli_version = mli->mli_version;
394 info.mli_v1_timer = mli->mli_v1_timer;
395 info.mli_v2_timer = mli->mli_v2_timer;
396 info.mli_flags = mli->mli_flags;
397 info.mli_rv = mli->mli_rv;
398 info.mli_qi = mli->mli_qi;
399 info.mli_qri = mli->mli_qri;
400 info.mli_uri = mli->mli_uri;
401 error = SYSCTL_OUT(req, &info, sizeof(info));
402 break;
403 }
404 }
405
406 out_locked:
407 NET_EPOCH_EXIT(et);
408 MLD_UNLOCK();
409 IN6_MULTI_LIST_UNLOCK();
410 IN6_MULTI_UNLOCK();
411 return (error);
412 }
413
414 /*
415 * Dispatch an entire queue of pending packet chains.
416 * VIMAGE: Assumes the vnet pointer has been set.
417 */
418 static void
mld_dispatch_queue(struct mbufq * mq,int limit)419 mld_dispatch_queue(struct mbufq *mq, int limit)
420 {
421 struct mbuf *m;
422
423 while ((m = mbufq_dequeue(mq)) != NULL) {
424 CTR3(KTR_MLD, "%s: dispatch %p from %p", __func__, mq, m);
425 mld_dispatch_packet(m);
426 if (--limit == 0)
427 break;
428 }
429 }
430
431 /*
432 * Filter outgoing MLD report state by group.
433 *
434 * Reports are ALWAYS suppressed for ALL-HOSTS (ff02::1)
435 * and node-local addresses. However, kernel and socket consumers
436 * always embed the KAME scope ID in the address provided, so strip it
437 * when performing comparison.
438 * Note: This is not the same as the *multicast* scope.
439 *
440 * Return zero if the given group is one for which MLD reports
441 * should be suppressed, or non-zero if reports should be issued.
442 */
443 static __inline int
mld_is_addr_reported(const struct in6_addr * addr)444 mld_is_addr_reported(const struct in6_addr *addr)
445 {
446
447 KASSERT(IN6_IS_ADDR_MULTICAST(addr), ("%s: not multicast", __func__));
448
449 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_NODELOCAL)
450 return (0);
451
452 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_LINKLOCAL) {
453 struct in6_addr tmp = *addr;
454 in6_clearscope(&tmp);
455 if (IN6_ARE_ADDR_EQUAL(&tmp, &in6addr_linklocal_allnodes))
456 return (0);
457 }
458
459 return (1);
460 }
461
462 /*
463 * Attach MLD when PF_INET6 is attached to an interface. Assumes that the
464 * current VNET is set by the caller.
465 */
466 struct mld_ifsoftc *
mld_domifattach(struct ifnet * ifp)467 mld_domifattach(struct ifnet *ifp)
468 {
469 struct mld_ifsoftc *mli;
470
471 CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp, if_name(ifp));
472
473 mli = malloc(sizeof(struct mld_ifsoftc), M_MLD, M_WAITOK | M_ZERO);
474 mli->mli_ifp = ifp;
475 mli->mli_version = MLD_VERSION_2;
476 mli->mli_flags = 0;
477 mli->mli_rv = MLD_RV_INIT;
478 mli->mli_qi = MLD_QI_INIT;
479 mli->mli_qri = MLD_QRI_INIT;
480 mli->mli_uri = MLD_URI_INIT;
481 mbufq_init(&mli->mli_gq, MLD_MAX_RESPONSE_PACKETS);
482 if ((ifp->if_flags & IFF_MULTICAST) == 0)
483 mli->mli_flags |= MLIF_SILENT;
484 if (mld_use_allow)
485 mli->mli_flags |= MLIF_USEALLOW;
486
487 MLD_LOCK();
488 LIST_INSERT_HEAD(&V_mli_head, mli, mli_link);
489 MLD_UNLOCK();
490
491 return (mli);
492 }
493
494 /*
495 * Hook for ifdetach.
496 *
497 * NOTE: Some finalization tasks need to run before the protocol domain
498 * is detached, but also before the link layer does its cleanup.
499 * Run before link-layer cleanup; cleanup groups, but do not free MLD state.
500 *
501 * SMPng: Caller must hold IN6_MULTI_LOCK().
502 * Must take IF_ADDR_LOCK() to cover if_multiaddrs iterator.
503 * XXX This routine is also bitten by unlocked ifma_protospec access.
504 */
505 void
mld_ifdetach(struct ifnet * ifp,struct in6_multi_head * inmh)506 mld_ifdetach(struct ifnet *ifp, struct in6_multi_head *inmh)
507 {
508 struct epoch_tracker et;
509 struct mld_ifsoftc *mli;
510 struct ifmultiaddr *ifma;
511 struct in6_multi *inm;
512
513 CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp,
514 if_name(ifp));
515
516 IN6_MULTI_LIST_LOCK_ASSERT();
517 MLD_LOCK();
518
519 mli = MLD_IFINFO(ifp);
520 IF_ADDR_WLOCK(ifp);
521 /*
522 * Extract list of in6_multi associated with the detaching ifp
523 * which the PF_INET6 layer is about to release.
524 */
525 NET_EPOCH_ENTER(et);
526 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
527 inm = in6m_ifmultiaddr_get_inm(ifma);
528 if (inm == NULL)
529 continue;
530 in6m_disconnect_locked(inmh, inm);
531
532 if (mli->mli_version == MLD_VERSION_2) {
533 in6m_clear_recorded(inm);
534
535 /*
536 * We need to release the final reference held
537 * for issuing the INCLUDE {}.
538 */
539 if (inm->in6m_state == MLD_LEAVING_MEMBER) {
540 inm->in6m_state = MLD_NOT_MEMBER;
541 in6m_rele_locked(inmh, inm);
542 }
543 }
544 }
545 NET_EPOCH_EXIT(et);
546 IF_ADDR_WUNLOCK(ifp);
547 MLD_UNLOCK();
548 }
549
550 /*
551 * Hook for domifdetach.
552 * Runs after link-layer cleanup; free MLD state.
553 *
554 * SMPng: Normally called with IF_AFDATA_LOCK held.
555 */
556 void
mld_domifdetach(struct ifnet * ifp)557 mld_domifdetach(struct ifnet *ifp)
558 {
559
560 CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
561 __func__, ifp, if_name(ifp));
562
563 MLD_LOCK();
564 mli_delete_locked(ifp);
565 MLD_UNLOCK();
566 }
567
568 static void
mli_delete_locked(struct ifnet * ifp)569 mli_delete_locked(struct ifnet *ifp)
570 {
571 struct mld_ifsoftc *mli, *tmli;
572
573 CTR3(KTR_MLD, "%s: freeing mld_ifsoftc for ifp %p(%s)",
574 __func__, ifp, if_name(ifp));
575
576 MLD_LOCK_ASSERT();
577
578 LIST_FOREACH_SAFE(mli, &V_mli_head, mli_link, tmli) {
579 if (mli->mli_ifp == ifp) {
580 /*
581 * Free deferred General Query responses.
582 */
583 mbufq_drain(&mli->mli_gq);
584
585 LIST_REMOVE(mli, mli_link);
586
587 free(mli, M_MLD);
588 return;
589 }
590 }
591 }
592
593 /*
594 * Process a received MLDv1 general or address-specific query.
595 * Assumes that the query header has been pulled up to sizeof(mld_hdr).
596 *
597 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
598 * mld_addr. This is OK as we own the mbuf chain.
599 */
600 static int
mld_v1_input_query(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)601 mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
602 /*const*/ struct mld_hdr *mld)
603 {
604 struct ifmultiaddr *ifma;
605 struct mld_ifsoftc *mli;
606 struct in6_multi *inm;
607 int is_general_query;
608 uint16_t timer;
609 #ifdef KTR
610 char ip6tbuf[INET6_ADDRSTRLEN];
611 #endif
612
613 NET_EPOCH_ASSERT();
614
615 is_general_query = 0;
616
617 if (!mld_v1enable) {
618 CTR3(KTR_MLD, "ignore v1 query %s on ifp %p(%s)",
619 ip6_sprintf(ip6tbuf, &mld->mld_addr),
620 ifp, if_name(ifp));
621 return (0);
622 }
623
624 /*
625 * RFC3810 Section 6.2: MLD queries must originate from
626 * a router's link-local address.
627 */
628 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
629 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
630 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
631 ifp, if_name(ifp));
632 return (0);
633 }
634
635 /*
636 * Do address field validation upfront before we accept
637 * the query.
638 */
639 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
640 /*
641 * MLDv1 General Query.
642 * If this was not sent to the all-nodes group, ignore it.
643 */
644 struct in6_addr dst;
645
646 dst = ip6->ip6_dst;
647 in6_clearscope(&dst);
648 if (!IN6_ARE_ADDR_EQUAL(&dst, &in6addr_linklocal_allnodes))
649 return (EINVAL);
650 is_general_query = 1;
651 } else {
652 /*
653 * Embed scope ID of receiving interface in MLD query for
654 * lookup whilst we don't hold other locks.
655 */
656 in6_setscope(&mld->mld_addr, ifp, NULL);
657 }
658
659 IN6_MULTI_LIST_LOCK();
660 MLD_LOCK();
661
662 /*
663 * Switch to MLDv1 host compatibility mode.
664 */
665 mli = MLD_IFINFO(ifp);
666 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
667 mld_set_version(mli, MLD_VERSION_1);
668
669 timer = (ntohs(mld->mld_maxdelay) * MLD_FASTHZ) / MLD_TIMER_SCALE;
670 if (timer == 0)
671 timer = 1;
672
673 if (is_general_query) {
674 /*
675 * For each reporting group joined on this
676 * interface, kick the report timer.
677 */
678 CTR2(KTR_MLD, "process v1 general query on ifp %p(%s)",
679 ifp, if_name(ifp));
680 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
681 inm = in6m_ifmultiaddr_get_inm(ifma);
682 if (inm == NULL)
683 continue;
684 mld_v1_update_group(inm, timer);
685 }
686 } else {
687 /*
688 * MLDv1 Group-Specific Query.
689 * If this is a group-specific MLDv1 query, we need only
690 * look up the single group to process it.
691 */
692 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
693 if (inm != NULL) {
694 CTR3(KTR_MLD, "process v1 query %s on ifp %p(%s)",
695 ip6_sprintf(ip6tbuf, &mld->mld_addr),
696 ifp, if_name(ifp));
697 mld_v1_update_group(inm, timer);
698 }
699 /* XXX Clear embedded scope ID as userland won't expect it. */
700 in6_clearscope(&mld->mld_addr);
701 }
702
703 MLD_UNLOCK();
704 IN6_MULTI_LIST_UNLOCK();
705
706 return (0);
707 }
708
709 /*
710 * Update the report timer on a group in response to an MLDv1 query.
711 *
712 * If we are becoming the reporting member for this group, start the timer.
713 * If we already are the reporting member for this group, and timer is
714 * below the threshold, reset it.
715 *
716 * We may be updating the group for the first time since we switched
717 * to MLDv2. If we are, then we must clear any recorded source lists,
718 * and transition to REPORTING state; the group timer is overloaded
719 * for group and group-source query responses.
720 *
721 * Unlike MLDv2, the delay per group should be jittered
722 * to avoid bursts of MLDv1 reports.
723 */
724 static void
mld_v1_update_group(struct in6_multi * inm,const int timer)725 mld_v1_update_group(struct in6_multi *inm, const int timer)
726 {
727 #ifdef KTR
728 char ip6tbuf[INET6_ADDRSTRLEN];
729 #endif
730
731 CTR4(KTR_MLD, "%s: %s/%s timer=%d", __func__,
732 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
733 if_name(inm->in6m_ifp), timer);
734
735 IN6_MULTI_LIST_LOCK_ASSERT();
736
737 switch (inm->in6m_state) {
738 case MLD_NOT_MEMBER:
739 case MLD_SILENT_MEMBER:
740 break;
741 case MLD_REPORTING_MEMBER:
742 if (inm->in6m_timer != 0 &&
743 inm->in6m_timer <= timer) {
744 CTR1(KTR_MLD, "%s: REPORTING and timer running, "
745 "skipping.", __func__);
746 break;
747 }
748 /* FALLTHROUGH */
749 case MLD_SG_QUERY_PENDING_MEMBER:
750 case MLD_G_QUERY_PENDING_MEMBER:
751 case MLD_IDLE_MEMBER:
752 case MLD_LAZY_MEMBER:
753 case MLD_AWAKENING_MEMBER:
754 CTR1(KTR_MLD, "%s: ->REPORTING", __func__);
755 inm->in6m_state = MLD_REPORTING_MEMBER;
756 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
757 V_current_state_timers_running6 = 1;
758 break;
759 case MLD_SLEEPING_MEMBER:
760 CTR1(KTR_MLD, "%s: ->AWAKENING", __func__);
761 inm->in6m_state = MLD_AWAKENING_MEMBER;
762 break;
763 case MLD_LEAVING_MEMBER:
764 break;
765 }
766 }
767
768 /*
769 * Process a received MLDv2 general, group-specific or
770 * group-and-source-specific query.
771 *
772 * Assumes that mld points to a struct mldv2_query which is stored in
773 * contiguous memory.
774 *
775 * Return 0 if successful, otherwise an appropriate error code is returned.
776 */
777 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)778 mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
779 struct mbuf *m, struct mldv2_query *mld, const int off, const int icmp6len)
780 {
781 struct mld_ifsoftc *mli;
782 struct in6_multi *inm;
783 uint32_t maxdelay, nsrc, qqi;
784 int is_general_query;
785 uint16_t timer;
786 uint8_t qrv;
787 #ifdef KTR
788 char ip6tbuf[INET6_ADDRSTRLEN];
789 #endif
790
791 NET_EPOCH_ASSERT();
792
793 if (!mld_v2enable) {
794 CTR3(KTR_MLD, "ignore v2 query src %s on ifp %p(%s)",
795 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
796 ifp, if_name(ifp));
797 return (0);
798 }
799
800 /*
801 * RFC3810 Section 6.2: MLD queries must originate from
802 * a router's link-local address.
803 */
804 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
805 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
806 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
807 ifp, if_name(ifp));
808 return (0);
809 }
810
811 is_general_query = 0;
812
813 CTR2(KTR_MLD, "input v2 query on ifp %p(%s)", ifp, if_name(ifp));
814
815 maxdelay = ntohs(mld->mld_maxdelay); /* in 1/10ths of a second */
816 if (maxdelay >= 32768) {
817 maxdelay = (MLD_MRC_MANT(maxdelay) | 0x1000) <<
818 (MLD_MRC_EXP(maxdelay) + 3);
819 }
820 timer = (maxdelay * MLD_FASTHZ) / MLD_TIMER_SCALE;
821 if (timer == 0)
822 timer = 1;
823
824 qrv = MLD_QRV(mld->mld_misc);
825 if (qrv < 2) {
826 CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
827 qrv, MLD_RV_INIT);
828 qrv = MLD_RV_INIT;
829 }
830
831 qqi = mld->mld_qqi;
832 if (qqi >= 128) {
833 qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
834 (MLD_QQIC_EXP(mld->mld_qqi) + 3);
835 }
836
837 nsrc = ntohs(mld->mld_numsrc);
838 if (nsrc > MLD_MAX_GS_SOURCES)
839 return (EMSGSIZE);
840 if (icmp6len < sizeof(struct mldv2_query) +
841 (nsrc * sizeof(struct in6_addr)))
842 return (EMSGSIZE);
843
844 /*
845 * Do further input validation upfront to avoid resetting timers
846 * should we need to discard this query.
847 */
848 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
849 /*
850 * A general query with a source list has undefined
851 * behaviour; discard it.
852 */
853 if (nsrc > 0)
854 return (EINVAL);
855 is_general_query = 1;
856 } else {
857 /*
858 * Embed scope ID of receiving interface in MLD query for
859 * lookup whilst we don't hold other locks (due to KAME
860 * locking lameness). We own this mbuf chain just now.
861 */
862 in6_setscope(&mld->mld_addr, ifp, NULL);
863 }
864
865 IN6_MULTI_LIST_LOCK();
866 MLD_LOCK();
867
868 mli = MLD_IFINFO(ifp);
869 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
870
871 /*
872 * Discard the v2 query if we're in Compatibility Mode.
873 * The RFC is pretty clear that hosts need to stay in MLDv1 mode
874 * until the Old Version Querier Present timer expires.
875 */
876 if (mli->mli_version != MLD_VERSION_2)
877 goto out_locked;
878
879 mld_set_version(mli, MLD_VERSION_2);
880 mli->mli_rv = qrv;
881 mli->mli_qi = qqi;
882 mli->mli_qri = maxdelay;
883
884 CTR4(KTR_MLD, "%s: qrv %d qi %d maxdelay %d", __func__, qrv, qqi,
885 maxdelay);
886
887 if (is_general_query) {
888 /*
889 * MLDv2 General Query.
890 *
891 * Schedule a current-state report on this ifp for
892 * all groups, possibly containing source lists.
893 *
894 * If there is a pending General Query response
895 * scheduled earlier than the selected delay, do
896 * not schedule any other reports.
897 * Otherwise, reset the interface timer.
898 */
899 CTR2(KTR_MLD, "process v2 general query on ifp %p(%s)",
900 ifp, if_name(ifp));
901 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer) {
902 mli->mli_v2_timer = MLD_RANDOM_DELAY(timer);
903 V_interface_timers_running6 = 1;
904 }
905 } else {
906 /*
907 * MLDv2 Group-specific or Group-and-source-specific Query.
908 *
909 * Group-source-specific queries are throttled on
910 * a per-group basis to defeat denial-of-service attempts.
911 * Queries for groups we are not a member of on this
912 * link are simply ignored.
913 */
914 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
915 if (inm == NULL)
916 goto out_locked;
917 if (nsrc > 0) {
918 if (!ratecheck(&inm->in6m_lastgsrtv,
919 &V_mld_gsrdelay)) {
920 CTR1(KTR_MLD, "%s: GS query throttled.",
921 __func__);
922 goto out_locked;
923 }
924 }
925 CTR2(KTR_MLD, "process v2 group query on ifp %p(%s)",
926 ifp, if_name(ifp));
927 /*
928 * If there is a pending General Query response
929 * scheduled sooner than the selected delay, no
930 * further report need be scheduled.
931 * Otherwise, prepare to respond to the
932 * group-specific or group-and-source query.
933 */
934 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer)
935 mld_v2_process_group_query(inm, mli, timer, m, mld, off);
936
937 /* XXX Clear embedded scope ID as userland won't expect it. */
938 in6_clearscope(&mld->mld_addr);
939 }
940
941 out_locked:
942 MLD_UNLOCK();
943 IN6_MULTI_LIST_UNLOCK();
944
945 return (0);
946 }
947
948 /*
949 * Process a received MLDv2 group-specific or group-and-source-specific
950 * query.
951 * Return <0 if any error occurred. Currently this is ignored.
952 */
953 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)954 mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifsoftc *mli,
955 int timer, struct mbuf *m0, struct mldv2_query *mld, const int off)
956 {
957 int retval;
958 uint16_t nsrc;
959
960 IN6_MULTI_LIST_LOCK_ASSERT();
961 MLD_LOCK_ASSERT();
962
963 retval = 0;
964
965 switch (inm->in6m_state) {
966 case MLD_NOT_MEMBER:
967 case MLD_SILENT_MEMBER:
968 case MLD_SLEEPING_MEMBER:
969 case MLD_LAZY_MEMBER:
970 case MLD_AWAKENING_MEMBER:
971 case MLD_IDLE_MEMBER:
972 case MLD_LEAVING_MEMBER:
973 return (retval);
974 break;
975 case MLD_REPORTING_MEMBER:
976 case MLD_G_QUERY_PENDING_MEMBER:
977 case MLD_SG_QUERY_PENDING_MEMBER:
978 break;
979 }
980
981 nsrc = ntohs(mld->mld_numsrc);
982
983 /* Length should be checked by calling function. */
984 KASSERT((m0->m_flags & M_PKTHDR) == 0 ||
985 m0->m_pkthdr.len >= off + sizeof(struct mldv2_query) +
986 nsrc * sizeof(struct in6_addr),
987 ("mldv2 packet is too short: (%d bytes < %zd bytes, m=%p)",
988 m0->m_pkthdr.len, off + sizeof(struct mldv2_query) +
989 nsrc * sizeof(struct in6_addr), m0));
990
991 /*
992 * Deal with group-specific queries upfront.
993 * If any group query is already pending, purge any recorded
994 * source-list state if it exists, and schedule a query response
995 * for this group-specific query.
996 */
997 if (nsrc == 0) {
998 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
999 inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER) {
1000 in6m_clear_recorded(inm);
1001 timer = min(inm->in6m_timer, timer);
1002 }
1003 inm->in6m_state = MLD_G_QUERY_PENDING_MEMBER;
1004 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1005 V_current_state_timers_running6 = 1;
1006 return (retval);
1007 }
1008
1009 /*
1010 * Deal with the case where a group-and-source-specific query has
1011 * been received but a group-specific query is already pending.
1012 */
1013 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER) {
1014 timer = min(inm->in6m_timer, timer);
1015 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1016 V_current_state_timers_running6 = 1;
1017 return (retval);
1018 }
1019
1020 /*
1021 * Finally, deal with the case where a group-and-source-specific
1022 * query has been received, where a response to a previous g-s-r
1023 * query exists, or none exists.
1024 * In this case, we need to parse the source-list which the Querier
1025 * has provided us with and check if we have any source list filter
1026 * entries at T1 for these sources. If we do not, there is no need
1027 * schedule a report and the query may be dropped.
1028 * If we do, we must record them and schedule a current-state
1029 * report for those sources.
1030 */
1031 if (inm->in6m_nsrc > 0) {
1032 struct in6_addr srcaddr;
1033 int i, nrecorded;
1034 int soff;
1035
1036 soff = off + sizeof(struct mldv2_query);
1037 nrecorded = 0;
1038 for (i = 0; i < nsrc; i++) {
1039 m_copydata(m0, soff, sizeof(struct in6_addr),
1040 (caddr_t)&srcaddr);
1041 retval = in6m_record_source(inm, &srcaddr);
1042 if (retval < 0)
1043 break;
1044 nrecorded += retval;
1045 soff += sizeof(struct in6_addr);
1046 }
1047 if (nrecorded > 0) {
1048 CTR1(KTR_MLD,
1049 "%s: schedule response to SG query", __func__);
1050 inm->in6m_state = MLD_SG_QUERY_PENDING_MEMBER;
1051 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1052 V_current_state_timers_running6 = 1;
1053 }
1054 }
1055
1056 return (retval);
1057 }
1058
1059 /*
1060 * Process a received MLDv1 host membership report.
1061 * Assumes mld points to mld_hdr in pulled up mbuf chain.
1062 *
1063 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
1064 * mld_addr. This is OK as we own the mbuf chain.
1065 */
1066 static int
mld_v1_input_report(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)1067 mld_v1_input_report(struct ifnet *ifp, const struct ip6_hdr *ip6,
1068 /*const*/ struct mld_hdr *mld)
1069 {
1070 struct in6_addr src, dst;
1071 struct in6_ifaddr *ia;
1072 struct in6_multi *inm;
1073 #ifdef KTR
1074 char ip6tbuf[INET6_ADDRSTRLEN];
1075 #endif
1076
1077 NET_EPOCH_ASSERT();
1078
1079 if (!mld_v1enable) {
1080 CTR3(KTR_MLD, "ignore v1 report %s on ifp %p(%s)",
1081 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1082 ifp, if_name(ifp));
1083 return (0);
1084 }
1085
1086 if (ifp->if_flags & IFF_LOOPBACK)
1087 return (0);
1088
1089 /*
1090 * MLDv1 reports must originate from a host's link-local address,
1091 * or the unspecified address (when booting).
1092 */
1093 src = ip6->ip6_src;
1094 in6_clearscope(&src);
1095 if (!IN6_IS_SCOPE_LINKLOCAL(&src) && !IN6_IS_ADDR_UNSPECIFIED(&src)) {
1096 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
1097 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
1098 ifp, if_name(ifp));
1099 return (EINVAL);
1100 }
1101
1102 /*
1103 * RFC2710 Section 4: MLDv1 reports must pertain to a multicast
1104 * group, and must be directed to the group itself.
1105 */
1106 dst = ip6->ip6_dst;
1107 in6_clearscope(&dst);
1108 if (!IN6_IS_ADDR_MULTICAST(&mld->mld_addr) ||
1109 !IN6_ARE_ADDR_EQUAL(&mld->mld_addr, &dst)) {
1110 CTR3(KTR_MLD, "ignore v1 query dst %s on ifp %p(%s)",
1111 ip6_sprintf(ip6tbuf, &ip6->ip6_dst),
1112 ifp, if_name(ifp));
1113 return (EINVAL);
1114 }
1115
1116 /*
1117 * Make sure we don't hear our own membership report, as fast
1118 * leave requires knowing that we are the only member of a
1119 * group. Assume we used the link-local address if available,
1120 * otherwise look for ::.
1121 *
1122 * XXX Note that scope ID comparison is needed for the address
1123 * returned by in6ifa_ifpforlinklocal(), but SHOULD NOT be
1124 * performed for the on-wire address.
1125 */
1126 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1127 if ((ia && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, IA6_IN6(ia))) ||
1128 (ia == NULL && IN6_IS_ADDR_UNSPECIFIED(&src))) {
1129 if (ia != NULL)
1130 ifa_free(&ia->ia_ifa);
1131 return (0);
1132 }
1133 if (ia != NULL)
1134 ifa_free(&ia->ia_ifa);
1135
1136 CTR3(KTR_MLD, "process v1 report %s on ifp %p(%s)",
1137 ip6_sprintf(ip6tbuf, &mld->mld_addr), ifp, if_name(ifp));
1138
1139 /*
1140 * Embed scope ID of receiving interface in MLD query for lookup
1141 * whilst we don't hold other locks (due to KAME locking lameness).
1142 */
1143 if (!IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr))
1144 in6_setscope(&mld->mld_addr, ifp, NULL);
1145
1146 IN6_MULTI_LIST_LOCK();
1147 MLD_LOCK();
1148
1149 /*
1150 * MLDv1 report suppression.
1151 * If we are a member of this group, and our membership should be
1152 * reported, and our group timer is pending or about to be reset,
1153 * stop our group timer by transitioning to the 'lazy' state.
1154 */
1155 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
1156 if (inm != NULL) {
1157 struct mld_ifsoftc *mli;
1158
1159 mli = inm->in6m_mli;
1160 KASSERT(mli != NULL,
1161 ("%s: no mli for ifp %p", __func__, ifp));
1162
1163 /*
1164 * If we are in MLDv2 host mode, do not allow the
1165 * other host's MLDv1 report to suppress our reports.
1166 */
1167 if (mli->mli_version == MLD_VERSION_2)
1168 goto out_locked;
1169
1170 inm->in6m_timer = 0;
1171
1172 switch (inm->in6m_state) {
1173 case MLD_NOT_MEMBER:
1174 case MLD_SILENT_MEMBER:
1175 case MLD_SLEEPING_MEMBER:
1176 break;
1177 case MLD_REPORTING_MEMBER:
1178 case MLD_IDLE_MEMBER:
1179 case MLD_AWAKENING_MEMBER:
1180 CTR3(KTR_MLD,
1181 "report suppressed for %s on ifp %p(%s)",
1182 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1183 ifp, if_name(ifp));
1184 case MLD_LAZY_MEMBER:
1185 inm->in6m_state = MLD_LAZY_MEMBER;
1186 break;
1187 case MLD_G_QUERY_PENDING_MEMBER:
1188 case MLD_SG_QUERY_PENDING_MEMBER:
1189 case MLD_LEAVING_MEMBER:
1190 break;
1191 }
1192 }
1193
1194 out_locked:
1195 MLD_UNLOCK();
1196 IN6_MULTI_LIST_UNLOCK();
1197
1198 /* XXX Clear embedded scope ID as userland won't expect it. */
1199 in6_clearscope(&mld->mld_addr);
1200
1201 return (0);
1202 }
1203
1204 /*
1205 * MLD input path.
1206 *
1207 * Assume query messages which fit in a single ICMPv6 message header
1208 * have been pulled up.
1209 * Assume that userland will want to see the message, even if it
1210 * otherwise fails kernel input validation; do not free it.
1211 * Pullup may however free the mbuf chain m if it fails.
1212 *
1213 * Return IPPROTO_DONE if we freed m. Otherwise, return 0.
1214 */
1215 int
mld_input(struct mbuf ** mp,int off,int icmp6len)1216 mld_input(struct mbuf **mp, int off, int icmp6len)
1217 {
1218 struct ifnet *ifp;
1219 struct ip6_hdr *ip6;
1220 struct mbuf *m;
1221 struct mld_hdr *mld;
1222 int mldlen;
1223
1224 m = *mp;
1225 CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
1226
1227 ifp = m->m_pkthdr.rcvif;
1228
1229 /* Pullup to appropriate size. */
1230 if (m->m_len < off + sizeof(*mld)) {
1231 m = m_pullup(m, off + sizeof(*mld));
1232 if (m == NULL) {
1233 ICMP6STAT_INC(icp6s_badlen);
1234 return (IPPROTO_DONE);
1235 }
1236 }
1237 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1238 if (mld->mld_type == MLD_LISTENER_QUERY &&
1239 icmp6len >= sizeof(struct mldv2_query)) {
1240 mldlen = sizeof(struct mldv2_query);
1241 } else {
1242 mldlen = sizeof(struct mld_hdr);
1243 }
1244 if (m->m_len < off + mldlen) {
1245 m = m_pullup(m, off + mldlen);
1246 if (m == NULL) {
1247 ICMP6STAT_INC(icp6s_badlen);
1248 return (IPPROTO_DONE);
1249 }
1250 }
1251 *mp = m;
1252 ip6 = mtod(m, struct ip6_hdr *);
1253 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1254
1255 /*
1256 * Userland needs to see all of this traffic for implementing
1257 * the endpoint discovery portion of multicast routing.
1258 */
1259 switch (mld->mld_type) {
1260 case MLD_LISTENER_QUERY:
1261 icmp6_ifstat_inc(ifp, ifs6_in_mldquery);
1262 if (icmp6len == sizeof(struct mld_hdr)) {
1263 if (mld_v1_input_query(ifp, ip6, mld) != 0)
1264 return (0);
1265 } else if (icmp6len >= sizeof(struct mldv2_query)) {
1266 if (mld_v2_input_query(ifp, ip6, m,
1267 (struct mldv2_query *)mld, off, icmp6len) != 0)
1268 return (0);
1269 }
1270 break;
1271 case MLD_LISTENER_REPORT:
1272 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1273 if (mld_v1_input_report(ifp, ip6, mld) != 0)
1274 return (0);
1275 break;
1276 case MLDV2_LISTENER_REPORT:
1277 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1278 break;
1279 case MLD_LISTENER_DONE:
1280 icmp6_ifstat_inc(ifp, ifs6_in_mlddone);
1281 break;
1282 default:
1283 break;
1284 }
1285
1286 return (0);
1287 }
1288
1289 /*
1290 * Fast timeout handler (global).
1291 * VIMAGE: Timeout handlers are expected to service all vimages.
1292 */
1293 static struct callout mldfast_callout;
1294 static void
mld_fasttimo(void * arg __unused)1295 mld_fasttimo(void *arg __unused)
1296 {
1297 struct epoch_tracker et;
1298 struct in6_multi_head inmh;
1299 VNET_ITERATOR_DECL(vnet_iter);
1300
1301 SLIST_INIT(&inmh);
1302
1303 NET_EPOCH_ENTER(et);
1304 VNET_LIST_RLOCK_NOSLEEP();
1305 VNET_FOREACH(vnet_iter) {
1306 CURVNET_SET(vnet_iter);
1307 mld_fasttimo_vnet(&inmh);
1308 CURVNET_RESTORE();
1309 }
1310 VNET_LIST_RUNLOCK_NOSLEEP();
1311 NET_EPOCH_EXIT(et);
1312 in6m_release_list_deferred(&inmh);
1313
1314 callout_reset(&mldfast_callout, hz / MLD_FASTHZ, mld_fasttimo, NULL);
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 mbufq scq; /* State-change packets */
1326 struct mbufq qrq; /* Query response packets */
1327 struct ifnet *ifp;
1328 struct mld_ifsoftc *mli;
1329 struct ifmultiaddr *ifma;
1330 struct in6_multi *inm;
1331 int uri_fasthz;
1332
1333 uri_fasthz = 0;
1334
1335 /*
1336 * Quick check to see if any work needs to be done, in order to
1337 * minimize the overhead of fasttimo processing.
1338 * SMPng: XXX Unlocked reads.
1339 */
1340 if (!V_current_state_timers_running6 &&
1341 !V_interface_timers_running6 &&
1342 !V_state_change_timers_running6)
1343 return;
1344
1345 IN6_MULTI_LIST_LOCK();
1346 MLD_LOCK();
1347
1348 /*
1349 * MLDv2 General Query response timer processing.
1350 */
1351 if (V_interface_timers_running6) {
1352 CTR1(KTR_MLD, "%s: interface timers running", __func__);
1353
1354 V_interface_timers_running6 = 0;
1355 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1356 if (mli->mli_v2_timer == 0) {
1357 /* Do nothing. */
1358 } else if (--mli->mli_v2_timer == 0) {
1359 mld_v2_dispatch_general_query(mli);
1360 } else {
1361 V_interface_timers_running6 = 1;
1362 }
1363 }
1364 }
1365
1366 if (!V_current_state_timers_running6 &&
1367 !V_state_change_timers_running6)
1368 goto out_locked;
1369
1370 V_current_state_timers_running6 = 0;
1371 V_state_change_timers_running6 = 0;
1372
1373 CTR1(KTR_MLD, "%s: state change timers running", __func__);
1374
1375 /*
1376 * MLD host report and state-change timer processing.
1377 * Note: Processing a v2 group timer may remove a node.
1378 */
1379 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1380 ifp = mli->mli_ifp;
1381
1382 if (mli->mli_version == MLD_VERSION_2) {
1383 uri_fasthz = MLD_RANDOM_DELAY(mli->mli_uri *
1384 MLD_FASTHZ);
1385 mbufq_init(&qrq, MLD_MAX_G_GS_PACKETS);
1386 mbufq_init(&scq, MLD_MAX_STATE_CHANGE_PACKETS);
1387 }
1388
1389 IF_ADDR_WLOCK(ifp);
1390 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1391 inm = in6m_ifmultiaddr_get_inm(ifma);
1392 if (inm == NULL)
1393 continue;
1394 switch (mli->mli_version) {
1395 case MLD_VERSION_1:
1396 mld_v1_process_group_timer(inmh, inm);
1397 break;
1398 case MLD_VERSION_2:
1399 mld_v2_process_group_timers(inmh, &qrq,
1400 &scq, inm, uri_fasthz);
1401 break;
1402 }
1403 }
1404 IF_ADDR_WUNLOCK(ifp);
1405
1406 switch (mli->mli_version) {
1407 case MLD_VERSION_1:
1408 /*
1409 * Transmit reports for this lifecycle. This
1410 * is done while not holding IF_ADDR_LOCK
1411 * since this can call
1412 * in6ifa_ifpforlinklocal() which locks
1413 * IF_ADDR_LOCK internally as well as
1414 * ip6_output() to transmit a packet.
1415 */
1416 while ((inm = SLIST_FIRST(inmh)) != NULL) {
1417 SLIST_REMOVE_HEAD(inmh, in6m_defer);
1418 (void)mld_v1_transmit_report(inm,
1419 MLD_LISTENER_REPORT);
1420 }
1421 break;
1422 case MLD_VERSION_2:
1423 mld_dispatch_queue(&qrq, 0);
1424 mld_dispatch_queue(&scq, 0);
1425 break;
1426 }
1427 }
1428
1429 out_locked:
1430 MLD_UNLOCK();
1431 IN6_MULTI_LIST_UNLOCK();
1432 }
1433
1434 /*
1435 * Update host report group timer.
1436 * Will update the global pending timer flags.
1437 */
1438 static void
mld_v1_process_group_timer(struct in6_multi_head * inmh,struct in6_multi * inm)1439 mld_v1_process_group_timer(struct in6_multi_head *inmh, struct in6_multi *inm)
1440 {
1441 int report_timer_expired;
1442
1443 IN6_MULTI_LIST_LOCK_ASSERT();
1444 MLD_LOCK_ASSERT();
1445
1446 if (inm->in6m_timer == 0) {
1447 report_timer_expired = 0;
1448 } else if (--inm->in6m_timer == 0) {
1449 report_timer_expired = 1;
1450 } else {
1451 V_current_state_timers_running6 = 1;
1452 return;
1453 }
1454
1455 switch (inm->in6m_state) {
1456 case MLD_NOT_MEMBER:
1457 case MLD_SILENT_MEMBER:
1458 case MLD_IDLE_MEMBER:
1459 case MLD_LAZY_MEMBER:
1460 case MLD_SLEEPING_MEMBER:
1461 case MLD_AWAKENING_MEMBER:
1462 break;
1463 case MLD_REPORTING_MEMBER:
1464 if (report_timer_expired) {
1465 inm->in6m_state = MLD_IDLE_MEMBER;
1466 SLIST_INSERT_HEAD(inmh, inm, in6m_defer);
1467 }
1468 break;
1469 case MLD_G_QUERY_PENDING_MEMBER:
1470 case MLD_SG_QUERY_PENDING_MEMBER:
1471 case MLD_LEAVING_MEMBER:
1472 break;
1473 }
1474 }
1475
1476 /*
1477 * Update a group's timers for MLDv2.
1478 * Will update the global pending timer flags.
1479 * Note: Unlocked read from mli.
1480 */
1481 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)1482 mld_v2_process_group_timers(struct in6_multi_head *inmh,
1483 struct mbufq *qrq, struct mbufq *scq,
1484 struct in6_multi *inm, const int uri_fasthz)
1485 {
1486 int query_response_timer_expired;
1487 int state_change_retransmit_timer_expired;
1488 #ifdef KTR
1489 char ip6tbuf[INET6_ADDRSTRLEN];
1490 #endif
1491
1492 IN6_MULTI_LIST_LOCK_ASSERT();
1493 MLD_LOCK_ASSERT();
1494
1495 query_response_timer_expired = 0;
1496 state_change_retransmit_timer_expired = 0;
1497
1498 /*
1499 * During a transition from compatibility mode back to MLDv2,
1500 * a group record in REPORTING state may still have its group
1501 * timer active. This is a no-op in this function; it is easier
1502 * to deal with it here than to complicate the slow-timeout path.
1503 */
1504 if (inm->in6m_timer == 0) {
1505 query_response_timer_expired = 0;
1506 } else if (--inm->in6m_timer == 0) {
1507 query_response_timer_expired = 1;
1508 } else {
1509 V_current_state_timers_running6 = 1;
1510 }
1511
1512 if (inm->in6m_sctimer == 0) {
1513 state_change_retransmit_timer_expired = 0;
1514 } else if (--inm->in6m_sctimer == 0) {
1515 state_change_retransmit_timer_expired = 1;
1516 } else {
1517 V_state_change_timers_running6 = 1;
1518 }
1519
1520 /* We are in fasttimo, so be quick about it. */
1521 if (!state_change_retransmit_timer_expired &&
1522 !query_response_timer_expired)
1523 return;
1524
1525 switch (inm->in6m_state) {
1526 case MLD_NOT_MEMBER:
1527 case MLD_SILENT_MEMBER:
1528 case MLD_SLEEPING_MEMBER:
1529 case MLD_LAZY_MEMBER:
1530 case MLD_AWAKENING_MEMBER:
1531 case MLD_IDLE_MEMBER:
1532 break;
1533 case MLD_G_QUERY_PENDING_MEMBER:
1534 case MLD_SG_QUERY_PENDING_MEMBER:
1535 /*
1536 * Respond to a previously pending Group-Specific
1537 * or Group-and-Source-Specific query by enqueueing
1538 * the appropriate Current-State report for
1539 * immediate transmission.
1540 */
1541 if (query_response_timer_expired) {
1542 int retval __unused;
1543
1544 retval = mld_v2_enqueue_group_record(qrq, inm, 0, 1,
1545 (inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER),
1546 0);
1547 CTR2(KTR_MLD, "%s: enqueue record = %d",
1548 __func__, retval);
1549 inm->in6m_state = MLD_REPORTING_MEMBER;
1550 in6m_clear_recorded(inm);
1551 }
1552 /* FALLTHROUGH */
1553 case MLD_REPORTING_MEMBER:
1554 case MLD_LEAVING_MEMBER:
1555 if (state_change_retransmit_timer_expired) {
1556 /*
1557 * State-change retransmission timer fired.
1558 * If there are any further pending retransmissions,
1559 * set the global pending state-change flag, and
1560 * reset the timer.
1561 */
1562 if (--inm->in6m_scrv > 0) {
1563 inm->in6m_sctimer = uri_fasthz;
1564 V_state_change_timers_running6 = 1;
1565 }
1566 /*
1567 * Retransmit the previously computed state-change
1568 * report. If there are no further pending
1569 * retransmissions, the mbuf queue will be consumed.
1570 * Update T0 state to T1 as we have now sent
1571 * a state-change.
1572 */
1573 (void)mld_v2_merge_state_changes(inm, scq);
1574
1575 in6m_commit(inm);
1576 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
1577 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1578 if_name(inm->in6m_ifp));
1579
1580 /*
1581 * If we are leaving the group for good, make sure
1582 * we release MLD's reference to it.
1583 * This release must be deferred using a SLIST,
1584 * as we are called from a loop which traverses
1585 * the in_ifmultiaddr TAILQ.
1586 */
1587 if (inm->in6m_state == MLD_LEAVING_MEMBER &&
1588 inm->in6m_scrv == 0) {
1589 inm->in6m_state = MLD_NOT_MEMBER;
1590 in6m_disconnect_locked(inmh, inm);
1591 in6m_rele_locked(inmh, inm);
1592 }
1593 }
1594 break;
1595 }
1596 }
1597
1598 /*
1599 * Switch to a different version on the given interface,
1600 * as per Section 9.12.
1601 */
1602 static void
mld_set_version(struct mld_ifsoftc * mli,const int version)1603 mld_set_version(struct mld_ifsoftc *mli, const int version)
1604 {
1605 int old_version_timer;
1606
1607 MLD_LOCK_ASSERT();
1608
1609 CTR4(KTR_MLD, "%s: switching to v%d on ifp %p(%s)", __func__,
1610 version, mli->mli_ifp, if_name(mli->mli_ifp));
1611
1612 if (version == MLD_VERSION_1) {
1613 /*
1614 * Compute the "Older Version Querier Present" timer as per
1615 * Section 9.12.
1616 */
1617 old_version_timer = (mli->mli_rv * mli->mli_qi) + mli->mli_qri;
1618 old_version_timer *= MLD_SLOWHZ;
1619 mli->mli_v1_timer = old_version_timer;
1620 }
1621
1622 if (mli->mli_v1_timer > 0 && mli->mli_version != MLD_VERSION_1) {
1623 mli->mli_version = MLD_VERSION_1;
1624 mld_v2_cancel_link_timers(mli);
1625 }
1626 }
1627
1628 /*
1629 * Cancel pending MLDv2 timers for the given link and all groups
1630 * joined on it; state-change, general-query, and group-query timers.
1631 */
1632 static void
mld_v2_cancel_link_timers(struct mld_ifsoftc * mli)1633 mld_v2_cancel_link_timers(struct mld_ifsoftc *mli)
1634 {
1635 struct epoch_tracker et;
1636 struct in6_multi_head inmh;
1637 struct ifmultiaddr *ifma;
1638 struct ifnet *ifp;
1639 struct in6_multi *inm;
1640
1641 CTR3(KTR_MLD, "%s: cancel v2 timers on ifp %p(%s)", __func__,
1642 mli->mli_ifp, if_name(mli->mli_ifp));
1643
1644 SLIST_INIT(&inmh);
1645 IN6_MULTI_LIST_LOCK_ASSERT();
1646 MLD_LOCK_ASSERT();
1647
1648 /*
1649 * Fast-track this potentially expensive operation
1650 * by checking all the global 'timer pending' flags.
1651 */
1652 if (!V_interface_timers_running6 &&
1653 !V_state_change_timers_running6 &&
1654 !V_current_state_timers_running6)
1655 return;
1656
1657 mli->mli_v2_timer = 0;
1658
1659 ifp = mli->mli_ifp;
1660
1661 IF_ADDR_WLOCK(ifp);
1662 NET_EPOCH_ENTER(et);
1663 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1664 inm = in6m_ifmultiaddr_get_inm(ifma);
1665 if (inm == NULL)
1666 continue;
1667 switch (inm->in6m_state) {
1668 case MLD_NOT_MEMBER:
1669 case MLD_SILENT_MEMBER:
1670 case MLD_IDLE_MEMBER:
1671 case MLD_LAZY_MEMBER:
1672 case MLD_SLEEPING_MEMBER:
1673 case MLD_AWAKENING_MEMBER:
1674 break;
1675 case MLD_LEAVING_MEMBER:
1676 /*
1677 * If we are leaving the group and switching
1678 * version, we need to release the final
1679 * reference held for issuing the INCLUDE {}.
1680 */
1681 if (inm->in6m_refcount == 1)
1682 in6m_disconnect_locked(&inmh, inm);
1683 in6m_rele_locked(&inmh, inm);
1684 /* FALLTHROUGH */
1685 case MLD_G_QUERY_PENDING_MEMBER:
1686 case MLD_SG_QUERY_PENDING_MEMBER:
1687 in6m_clear_recorded(inm);
1688 /* FALLTHROUGH */
1689 case MLD_REPORTING_MEMBER:
1690 inm->in6m_sctimer = 0;
1691 inm->in6m_timer = 0;
1692 inm->in6m_state = MLD_REPORTING_MEMBER;
1693 /*
1694 * Free any pending MLDv2 state-change records.
1695 */
1696 mbufq_drain(&inm->in6m_scq);
1697 break;
1698 }
1699 }
1700 NET_EPOCH_EXIT(et);
1701 IF_ADDR_WUNLOCK(ifp);
1702 in6m_release_list_deferred(&inmh);
1703 }
1704
1705 /*
1706 * Global slowtimo handler.
1707 * VIMAGE: Timeout handlers are expected to service all vimages.
1708 */
1709 static struct callout mldslow_callout;
1710 static void
mld_slowtimo(void * arg __unused)1711 mld_slowtimo(void *arg __unused)
1712 {
1713 VNET_ITERATOR_DECL(vnet_iter);
1714
1715 VNET_LIST_RLOCK_NOSLEEP();
1716 VNET_FOREACH(vnet_iter) {
1717 CURVNET_SET(vnet_iter);
1718 mld_slowtimo_vnet();
1719 CURVNET_RESTORE();
1720 }
1721 VNET_LIST_RUNLOCK_NOSLEEP();
1722
1723 callout_reset(&mldslow_callout, hz / MLD_SLOWHZ, mld_slowtimo, NULL);
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 MLD_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 MLD_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 * MLD_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 __diagused;
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.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.vt_nrecs = 1;
2548 mbufq_enqueue(mq, m);
2549 } else
2550 m->m_pkthdr.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.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 uint8_t mode, now, then;
2674 rectype_t crt, drt, nrt;
2675 #ifdef KTR
2676 int nallow, nblock;
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 #ifdef KTR
2697 nallow = 0; /* # of source entries in ALLOW_NEW */
2698 nblock = 0; /* # of source entries in BLOCK_OLD */
2699 #endif
2700 nims = NULL; /* next tree node pointer */
2701
2702 /*
2703 * For each possible filter record mode.
2704 * The first kind of source we encounter tells us which
2705 * is the first kind of record we start appending.
2706 * If a node transitioned to UNDEFINED at t1, its mode is treated
2707 * as the inverse of the group's filter mode.
2708 */
2709 while (drt != REC_FULL) {
2710 do {
2711 m0 = mbufq_last(mq);
2712 if (m0 != NULL &&
2713 (m0->m_pkthdr.vt_nrecs + 1 <=
2714 MLD_V2_REPORT_MAXRECS) &&
2715 (m0->m_pkthdr.len + MINRECLEN) <
2716 (ifp->if_mtu - MLD_MTUSPACE)) {
2717 m = m0;
2718 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2719 sizeof(struct mldv2_record)) /
2720 sizeof(struct in6_addr);
2721 CTR1(KTR_MLD,
2722 "%s: use previous packet", __func__);
2723 } else {
2724 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2725 if (m == NULL)
2726 m = m_gethdr(M_NOWAIT, MT_DATA);
2727 if (m == NULL) {
2728 CTR1(KTR_MLD,
2729 "%s: m_get*() failed", __func__);
2730 return (-ENOMEM);
2731 }
2732 m->m_pkthdr.vt_nrecs = 0;
2733 mld_save_context(m, ifp);
2734 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2735 sizeof(struct mldv2_record)) /
2736 sizeof(struct in6_addr);
2737 npbytes = 0;
2738 CTR1(KTR_MLD,
2739 "%s: allocated new packet", __func__);
2740 }
2741 /*
2742 * Append the MLD group record header to the
2743 * current packet's data area.
2744 * Recalculate pointer to free space for next
2745 * group record, in case m_append() allocated
2746 * a new mbuf or cluster.
2747 */
2748 memset(&mr, 0, sizeof(mr));
2749 mr.mr_addr = inm->in6m_addr;
2750 in6_clearscope(&mr.mr_addr);
2751 if (!m_append(m, sizeof(mr), (void *)&mr)) {
2752 if (m != m0)
2753 m_freem(m);
2754 CTR1(KTR_MLD,
2755 "%s: m_append() failed", __func__);
2756 return (-ENOMEM);
2757 }
2758 npbytes += sizeof(struct mldv2_record);
2759 if (m != m0) {
2760 /* new packet; offset in chain */
2761 md = m_getptr(m, npbytes -
2762 sizeof(struct mldv2_record), &off);
2763 pmr = (struct mldv2_record *)(mtod(md,
2764 uint8_t *) + off);
2765 } else {
2766 /* current packet; offset from last append */
2767 md = m_last(m);
2768 pmr = (struct mldv2_record *)(mtod(md,
2769 uint8_t *) + md->m_len -
2770 sizeof(struct mldv2_record));
2771 }
2772 /*
2773 * Begin walking the tree for this record type
2774 * pass, or continue from where we left off
2775 * previously if we had to allocate a new packet.
2776 * Only report deltas in-mode at t1.
2777 * We need not report included sources as allowed
2778 * if we are in inclusive mode on the group,
2779 * however the converse is not true.
2780 */
2781 rsrcs = 0;
2782 if (nims == NULL) {
2783 nims = RB_MIN(ip6_msource_tree,
2784 &inm->in6m_srcs);
2785 }
2786 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2787 CTR2(KTR_MLD, "%s: visit node %s", __func__,
2788 ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2789 now = im6s_get_mode(inm, ims, 1);
2790 then = im6s_get_mode(inm, ims, 0);
2791 CTR3(KTR_MLD, "%s: mode: t0 %d, t1 %d",
2792 __func__, then, now);
2793 if (now == then) {
2794 CTR1(KTR_MLD,
2795 "%s: skip unchanged", __func__);
2796 continue;
2797 }
2798 if (mode == MCAST_EXCLUDE &&
2799 now == MCAST_INCLUDE) {
2800 CTR1(KTR_MLD,
2801 "%s: skip IN src on EX group",
2802 __func__);
2803 continue;
2804 }
2805 nrt = (rectype_t)now;
2806 if (nrt == REC_NONE)
2807 nrt = (rectype_t)(~mode & REC_FULL);
2808 if (schanged++ == 0) {
2809 crt = nrt;
2810 } else if (crt != nrt)
2811 continue;
2812 if (!m_append(m, sizeof(struct in6_addr),
2813 (void *)&ims->im6s_addr)) {
2814 if (m != m0)
2815 m_freem(m);
2816 CTR1(KTR_MLD,
2817 "%s: m_append() failed", __func__);
2818 return (-ENOMEM);
2819 }
2820 #ifdef KTR
2821 nallow += !!(crt == REC_ALLOW);
2822 nblock += !!(crt == REC_BLOCK);
2823 #endif
2824 if (++rsrcs == m0srcs)
2825 break;
2826 }
2827 /*
2828 * If we did not append any tree nodes on this
2829 * pass, back out of allocations.
2830 */
2831 if (rsrcs == 0) {
2832 npbytes -= sizeof(struct mldv2_record);
2833 if (m != m0) {
2834 CTR1(KTR_MLD,
2835 "%s: m_free(m)", __func__);
2836 m_freem(m);
2837 } else {
2838 CTR1(KTR_MLD,
2839 "%s: m_adj(m, -mr)", __func__);
2840 m_adj(m, -((int)sizeof(
2841 struct mldv2_record)));
2842 }
2843 continue;
2844 }
2845 npbytes += (rsrcs * sizeof(struct in6_addr));
2846 if (crt == REC_ALLOW)
2847 pmr->mr_type = MLD_ALLOW_NEW_SOURCES;
2848 else if (crt == REC_BLOCK)
2849 pmr->mr_type = MLD_BLOCK_OLD_SOURCES;
2850 pmr->mr_numsrc = htons(rsrcs);
2851 /*
2852 * Count the new group record, and enqueue this
2853 * packet if it wasn't already queued.
2854 */
2855 m->m_pkthdr.vt_nrecs++;
2856 if (m != m0)
2857 mbufq_enqueue(mq, m);
2858 nbytes += npbytes;
2859 } while (nims != NULL);
2860 drt |= crt;
2861 crt = (~crt & REC_FULL);
2862 }
2863
2864 CTR3(KTR_MLD, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
2865 nallow, nblock);
2866
2867 return (nbytes);
2868 }
2869
2870 static int
mld_v2_merge_state_changes(struct in6_multi * inm,struct mbufq * scq)2871 mld_v2_merge_state_changes(struct in6_multi *inm, struct mbufq *scq)
2872 {
2873 struct mbufq *gq;
2874 struct mbuf *m; /* pending state-change */
2875 struct mbuf *m0; /* copy of pending state-change */
2876 struct mbuf *mt; /* last state-change in packet */
2877 int docopy, domerge;
2878 u_int recslen;
2879
2880 docopy = 0;
2881 domerge = 0;
2882 recslen = 0;
2883
2884 IN6_MULTI_LIST_LOCK_ASSERT();
2885 MLD_LOCK_ASSERT();
2886
2887 /*
2888 * If there are further pending retransmissions, make a writable
2889 * copy of each queued state-change message before merging.
2890 */
2891 if (inm->in6m_scrv > 0)
2892 docopy = 1;
2893
2894 gq = &inm->in6m_scq;
2895 #ifdef KTR
2896 if (mbufq_first(gq) == NULL) {
2897 CTR2(KTR_MLD, "%s: WARNING: queue for inm %p is empty",
2898 __func__, inm);
2899 }
2900 #endif
2901
2902 m = mbufq_first(gq);
2903 while (m != NULL) {
2904 /*
2905 * Only merge the report into the current packet if
2906 * there is sufficient space to do so; an MLDv2 report
2907 * packet may only contain 65,535 group records.
2908 * Always use a simple mbuf chain concatentation to do this,
2909 * as large state changes for single groups may have
2910 * allocated clusters.
2911 */
2912 domerge = 0;
2913 mt = mbufq_last(scq);
2914 if (mt != NULL) {
2915 recslen = m_length(m, NULL);
2916
2917 if ((mt->m_pkthdr.vt_nrecs +
2918 m->m_pkthdr.vt_nrecs <=
2919 MLD_V2_REPORT_MAXRECS) &&
2920 (mt->m_pkthdr.len + recslen <=
2921 (inm->in6m_ifp->if_mtu - MLD_MTUSPACE)))
2922 domerge = 1;
2923 }
2924
2925 if (!domerge && mbufq_full(gq)) {
2926 CTR2(KTR_MLD,
2927 "%s: outbound queue full, skipping whole packet %p",
2928 __func__, m);
2929 mt = m->m_nextpkt;
2930 if (!docopy)
2931 m_freem(m);
2932 m = mt;
2933 continue;
2934 }
2935
2936 if (!docopy) {
2937 CTR2(KTR_MLD, "%s: dequeueing %p", __func__, m);
2938 m0 = mbufq_dequeue(gq);
2939 m = m0->m_nextpkt;
2940 } else {
2941 CTR2(KTR_MLD, "%s: copying %p", __func__, m);
2942 m0 = m_dup(m, M_NOWAIT);
2943 if (m0 == NULL)
2944 return (ENOMEM);
2945 m0->m_nextpkt = NULL;
2946 m = m->m_nextpkt;
2947 }
2948
2949 if (!domerge) {
2950 CTR3(KTR_MLD, "%s: queueing %p to scq %p)",
2951 __func__, m0, scq);
2952 mbufq_enqueue(scq, m0);
2953 } else {
2954 struct mbuf *mtl; /* last mbuf of packet mt */
2955
2956 CTR3(KTR_MLD, "%s: merging %p with ifscq tail %p)",
2957 __func__, m0, mt);
2958
2959 mtl = m_last(mt);
2960 m0->m_flags &= ~M_PKTHDR;
2961 mt->m_pkthdr.len += recslen;
2962 mt->m_pkthdr.vt_nrecs +=
2963 m0->m_pkthdr.vt_nrecs;
2964
2965 mtl->m_next = m0;
2966 }
2967 }
2968
2969 return (0);
2970 }
2971
2972 /*
2973 * Respond to a pending MLDv2 General Query.
2974 */
2975 static void
mld_v2_dispatch_general_query(struct mld_ifsoftc * mli)2976 mld_v2_dispatch_general_query(struct mld_ifsoftc *mli)
2977 {
2978 struct ifmultiaddr *ifma;
2979 struct ifnet *ifp;
2980 struct in6_multi *inm;
2981 int retval __unused;
2982
2983 NET_EPOCH_ASSERT();
2984 IN6_MULTI_LIST_LOCK_ASSERT();
2985 MLD_LOCK_ASSERT();
2986
2987 KASSERT(mli->mli_version == MLD_VERSION_2,
2988 ("%s: called when version %d", __func__, mli->mli_version));
2989
2990 /*
2991 * Check that there are some packets queued. If so, send them first.
2992 * For large number of groups the reply to general query can take
2993 * many packets, we should finish sending them before starting of
2994 * queuing the new reply.
2995 */
2996 if (!mbufq_empty(&mli->mli_gq))
2997 goto send;
2998
2999 ifp = mli->mli_ifp;
3000
3001 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
3002 inm = in6m_ifmultiaddr_get_inm(ifma);
3003 if (inm == NULL)
3004 continue;
3005 KASSERT(ifp == inm->in6m_ifp,
3006 ("%s: inconsistent ifp", __func__));
3007
3008 switch (inm->in6m_state) {
3009 case MLD_NOT_MEMBER:
3010 case MLD_SILENT_MEMBER:
3011 break;
3012 case MLD_REPORTING_MEMBER:
3013 case MLD_IDLE_MEMBER:
3014 case MLD_LAZY_MEMBER:
3015 case MLD_SLEEPING_MEMBER:
3016 case MLD_AWAKENING_MEMBER:
3017 inm->in6m_state = MLD_REPORTING_MEMBER;
3018 retval = mld_v2_enqueue_group_record(&mli->mli_gq,
3019 inm, 0, 0, 0, 0);
3020 CTR2(KTR_MLD, "%s: enqueue record = %d",
3021 __func__, retval);
3022 break;
3023 case MLD_G_QUERY_PENDING_MEMBER:
3024 case MLD_SG_QUERY_PENDING_MEMBER:
3025 case MLD_LEAVING_MEMBER:
3026 break;
3027 }
3028 }
3029
3030 send:
3031 mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST);
3032
3033 /*
3034 * Slew transmission of bursts over 500ms intervals.
3035 */
3036 if (mbufq_first(&mli->mli_gq) != NULL) {
3037 mli->mli_v2_timer = 1 + MLD_RANDOM_DELAY(
3038 MLD_RESPONSE_BURST_INTERVAL);
3039 V_interface_timers_running6 = 1;
3040 }
3041 }
3042
3043 /*
3044 * Transmit the next pending message in the output queue.
3045 *
3046 * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
3047 * MRT: Nothing needs to be done, as MLD traffic is always local to
3048 * a link and uses a link-scope multicast address.
3049 */
3050 static void
mld_dispatch_packet(struct mbuf * m)3051 mld_dispatch_packet(struct mbuf *m)
3052 {
3053 struct ip6_moptions im6o;
3054 struct ifnet *ifp;
3055 struct ifnet *oifp;
3056 struct mbuf *m0;
3057 struct mbuf *md;
3058 struct ip6_hdr *ip6;
3059 struct mld_hdr *mld;
3060 int error;
3061 int off;
3062 int type;
3063 uint32_t ifindex;
3064
3065 CTR2(KTR_MLD, "%s: transmit %p", __func__, m);
3066 NET_EPOCH_ASSERT();
3067
3068 /*
3069 * Set VNET image pointer from enqueued mbuf chain
3070 * before doing anything else. Whilst we use interface
3071 * indexes to guard against interface detach, they are
3072 * unique to each VIMAGE and must be retrieved.
3073 */
3074 ifindex = mld_restore_context(m);
3075
3076 /*
3077 * Check if the ifnet still exists. This limits the scope of
3078 * any race in the absence of a global ifp lock for low cost
3079 * (an array lookup).
3080 */
3081 ifp = ifnet_byindex(ifindex);
3082 if (ifp == NULL) {
3083 CTR3(KTR_MLD, "%s: dropped %p as ifindex %u went away.",
3084 __func__, m, ifindex);
3085 m_freem(m);
3086 IP6STAT_INC(ip6s_noroute);
3087 goto out;
3088 }
3089
3090 im6o.im6o_multicast_hlim = 1;
3091 im6o.im6o_multicast_loop = (V_ip6_mrouter != NULL);
3092 im6o.im6o_multicast_ifp = ifp;
3093
3094 if (m->m_flags & M_MLDV1) {
3095 m0 = m;
3096 } else {
3097 m0 = mld_v2_encap_report(ifp, m);
3098 if (m0 == NULL) {
3099 CTR2(KTR_MLD, "%s: dropped %p", __func__, m);
3100 IP6STAT_INC(ip6s_odropped);
3101 goto out;
3102 }
3103 }
3104
3105 mld_scrub_context(m0);
3106 m_clrprotoflags(m);
3107 m0->m_pkthdr.rcvif = V_loif;
3108
3109 ip6 = mtod(m0, struct ip6_hdr *);
3110 #if 0
3111 (void)in6_setscope(&ip6->ip6_dst, ifp, NULL); /* XXX LOR */
3112 #else
3113 /*
3114 * XXX XXX Break some KPI rules to prevent an LOR which would
3115 * occur if we called in6_setscope() at transmission.
3116 * See comments at top of file.
3117 */
3118 MLD_EMBEDSCOPE(&ip6->ip6_dst, ifp->if_index);
3119 #endif
3120
3121 /*
3122 * Retrieve the ICMPv6 type before handoff to ip6_output(),
3123 * so we can bump the stats.
3124 */
3125 md = m_getptr(m0, sizeof(struct ip6_hdr), &off);
3126 mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off);
3127 type = mld->mld_type;
3128
3129 oifp = NULL;
3130 error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o,
3131 &oifp, NULL);
3132 if (error) {
3133 CTR3(KTR_MLD, "%s: ip6_output(%p) = %d", __func__, m0, error);
3134 goto out;
3135 }
3136 ICMP6STAT_INC2(icp6s_outhist, type);
3137 if (oifp != NULL) {
3138 icmp6_ifstat_inc(oifp, ifs6_out_msg);
3139 switch (type) {
3140 case MLD_LISTENER_REPORT:
3141 case MLDV2_LISTENER_REPORT:
3142 icmp6_ifstat_inc(oifp, ifs6_out_mldreport);
3143 break;
3144 case MLD_LISTENER_DONE:
3145 icmp6_ifstat_inc(oifp, ifs6_out_mlddone);
3146 break;
3147 }
3148 }
3149 out:
3150 return;
3151 }
3152
3153 /*
3154 * Encapsulate an MLDv2 report.
3155 *
3156 * KAME IPv6 requires that hop-by-hop options be passed separately,
3157 * and that the IPv6 header be prepended in a separate mbuf.
3158 *
3159 * Returns a pointer to the new mbuf chain head, or NULL if the
3160 * allocation failed.
3161 */
3162 static struct mbuf *
mld_v2_encap_report(struct ifnet * ifp,struct mbuf * m)3163 mld_v2_encap_report(struct ifnet *ifp, struct mbuf *m)
3164 {
3165 struct mbuf *mh;
3166 struct mldv2_report *mld;
3167 struct ip6_hdr *ip6;
3168 struct in6_ifaddr *ia;
3169 int mldreclen;
3170
3171 KASSERT(ifp != NULL, ("%s: null ifp", __func__));
3172 KASSERT((m->m_flags & M_PKTHDR),
3173 ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
3174
3175 /*
3176 * RFC3590: OK to send as :: or tentative during DAD.
3177 */
3178 NET_EPOCH_ASSERT();
3179 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
3180 if (ia == NULL)
3181 CTR1(KTR_MLD, "%s: warning: ia is NULL", __func__);
3182
3183 mh = m_gethdr(M_NOWAIT, MT_DATA);
3184 if (mh == NULL) {
3185 if (ia != NULL)
3186 ifa_free(&ia->ia_ifa);
3187 m_freem(m);
3188 return (NULL);
3189 }
3190 M_ALIGN(mh, sizeof(struct ip6_hdr) + sizeof(struct mldv2_report));
3191
3192 mldreclen = m_length(m, NULL);
3193 CTR2(KTR_MLD, "%s: mldreclen is %d", __func__, mldreclen);
3194
3195 mh->m_len = sizeof(struct ip6_hdr) + sizeof(struct mldv2_report);
3196 mh->m_pkthdr.len = sizeof(struct ip6_hdr) +
3197 sizeof(struct mldv2_report) + mldreclen;
3198
3199 ip6 = mtod(mh, struct ip6_hdr *);
3200 ip6->ip6_flow = 0;
3201 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
3202 ip6->ip6_vfc |= IPV6_VERSION;
3203 ip6->ip6_nxt = IPPROTO_ICMPV6;
3204 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
3205 if (ia != NULL)
3206 ifa_free(&ia->ia_ifa);
3207 ip6->ip6_dst = in6addr_linklocal_allv2routers;
3208 /* scope ID will be set in netisr */
3209
3210 mld = (struct mldv2_report *)(ip6 + 1);
3211 mld->mld_type = MLDV2_LISTENER_REPORT;
3212 mld->mld_code = 0;
3213 mld->mld_cksum = 0;
3214 mld->mld_v2_reserved = 0;
3215 mld->mld_v2_numrecs = htons(m->m_pkthdr.vt_nrecs);
3216 m->m_pkthdr.vt_nrecs = 0;
3217
3218 mh->m_next = m;
3219 mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
3220 sizeof(struct ip6_hdr), sizeof(struct mldv2_report) + mldreclen);
3221 return (mh);
3222 }
3223
3224 #ifdef KTR
3225 static char *
mld_rec_type_to_str(const int type)3226 mld_rec_type_to_str(const int type)
3227 {
3228
3229 switch (type) {
3230 case MLD_CHANGE_TO_EXCLUDE_MODE:
3231 return "TO_EX";
3232 break;
3233 case MLD_CHANGE_TO_INCLUDE_MODE:
3234 return "TO_IN";
3235 break;
3236 case MLD_MODE_IS_EXCLUDE:
3237 return "MODE_EX";
3238 break;
3239 case MLD_MODE_IS_INCLUDE:
3240 return "MODE_IN";
3241 break;
3242 case MLD_ALLOW_NEW_SOURCES:
3243 return "ALLOW_NEW";
3244 break;
3245 case MLD_BLOCK_OLD_SOURCES:
3246 return "BLOCK_OLD";
3247 break;
3248 default:
3249 break;
3250 }
3251 return "unknown";
3252 }
3253 #endif
3254
3255 static void
mld_init(void * unused __unused)3256 mld_init(void *unused __unused)
3257 {
3258
3259 CTR1(KTR_MLD, "%s: initializing", __func__);
3260 MLD_LOCK_INIT();
3261
3262 ip6_initpktopts(&mld_po);
3263 mld_po.ip6po_hlim = 1;
3264 mld_po.ip6po_hbh = &mld_ra.hbh;
3265 mld_po.ip6po_prefer_tempaddr = IP6PO_TEMPADDR_NOTPREFER;
3266 mld_po.ip6po_flags = IP6PO_DONTFRAG;
3267
3268 callout_init(&mldslow_callout, 1);
3269 callout_reset(&mldslow_callout, hz / MLD_SLOWHZ, mld_slowtimo, NULL);
3270 callout_init(&mldfast_callout, 1);
3271 callout_reset(&mldfast_callout, hz / MLD_FASTHZ, mld_fasttimo, NULL);
3272 }
3273 SYSINIT(mld_init, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_init, NULL);
3274
3275 static void
mld_uninit(void * unused __unused)3276 mld_uninit(void *unused __unused)
3277 {
3278
3279 CTR1(KTR_MLD, "%s: tearing down", __func__);
3280 callout_drain(&mldslow_callout);
3281 callout_drain(&mldfast_callout);
3282 MLD_LOCK_DESTROY();
3283 }
3284 SYSUNINIT(mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_uninit, NULL);
3285
3286 static void
vnet_mld_init(const void * unused __unused)3287 vnet_mld_init(const void *unused __unused)
3288 {
3289
3290 CTR1(KTR_MLD, "%s: initializing", __func__);
3291
3292 LIST_INIT(&V_mli_head);
3293 }
3294 VNET_SYSINIT(vnet_mld_init, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_init,
3295 NULL);
3296
3297 static void
vnet_mld_uninit(const void * unused __unused)3298 vnet_mld_uninit(const void *unused __unused)
3299 {
3300
3301 /* This can happen if we shutdown the network stack. */
3302 CTR1(KTR_MLD, "%s: tearing down", __func__);
3303 }
3304 VNET_SYSUNINIT(vnet_mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_uninit,
3305 NULL);
3306
3307 static int
mld_modevent(module_t mod,int type,void * unused __unused)3308 mld_modevent(module_t mod, int type, void *unused __unused)
3309 {
3310
3311 switch (type) {
3312 case MOD_LOAD:
3313 case MOD_UNLOAD:
3314 break;
3315 default:
3316 return (EOPNOTSUPP);
3317 }
3318 return (0);
3319 }
3320
3321 static moduledata_t mld_mod = {
3322 "mld",
3323 mld_modevent,
3324 0
3325 };
3326 DECLARE_MODULE(mld, mld_mod, SI_SUB_PROTO_MC, SI_ORDER_ANY);
3327