1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2009 Bruce Simpson.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $
31 */
32
33 /*-
34 * Copyright (c) 1988 Stephen Deering.
35 * Copyright (c) 1992, 1993
36 * The Regents of the University of California. All rights reserved.
37 *
38 * This code is derived from software contributed to Berkeley by
39 * Stephen Deering of Stanford University.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 * 3. Neither the name of the University nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
65 * @(#)igmp.c 8.1 (Berkeley) 7/19/93
66 */
67
68 #include <sys/cdefs.h>
69 __FBSDID("$FreeBSD: stable/12/sys/netinet6/mld6.c 358542 2020-03-02 13:23:28Z bz $");
70
71 #include "opt_inet.h"
72 #include "opt_inet6.h"
73
74 #include <sys/param.h>
75 #include <sys/systm.h>
76 #include <sys/mbuf.h>
77 #include <sys/socket.h>
78 #include <sys/protosw.h>
79 #include <sys/sysctl.h>
80 #include <sys/kernel.h>
81 #include <sys/callout.h>
82 #include <sys/malloc.h>
83 #include <sys/module.h>
84 #include <sys/ktr.h>
85
86 #include <net/if.h>
87 #include <net/if_var.h>
88 #include <net/route.h>
89 #include <net/vnet.h>
90
91 #include <netinet/in.h>
92 #include <netinet/in_var.h>
93 #include <netinet6/in6_var.h>
94 #include <netinet/ip6.h>
95 #include <netinet6/ip6_var.h>
96 #include <netinet6/scope6_var.h>
97 #include <netinet/icmp6.h>
98 #include <netinet6/mld6.h>
99 #include <netinet6/mld6_var.h>
100
101 #include <security/mac/mac_framework.h>
102
103 #ifndef KTR_MLD
104 #define KTR_MLD KTR_INET6
105 #endif
106
107 static struct mld_ifsoftc *
108 mli_alloc_locked(struct ifnet *);
109 static void mli_delete_locked(const struct ifnet *);
110 static void mld_dispatch_packet(struct mbuf *);
111 static void mld_dispatch_queue(struct mbufq *, int);
112 static void mld_final_leave(struct in6_multi *, struct mld_ifsoftc *);
113 static void mld_fasttimo_vnet(struct in6_multi_head *inmh);
114 static int mld_handle_state_change(struct in6_multi *,
115 struct mld_ifsoftc *);
116 static int mld_initial_join(struct in6_multi *, struct mld_ifsoftc *,
117 const int);
118 #ifdef KTR
119 static char * mld_rec_type_to_str(const int);
120 #endif
121 static void mld_set_version(struct mld_ifsoftc *, const int);
122 static void mld_slowtimo_vnet(void);
123 static int mld_v1_input_query(struct ifnet *, const struct ip6_hdr *,
124 /*const*/ struct mld_hdr *);
125 static int mld_v1_input_report(struct ifnet *, const struct ip6_hdr *,
126 /*const*/ struct mld_hdr *);
127 static void mld_v1_process_group_timer(struct in6_multi_head *,
128 struct in6_multi *);
129 static void mld_v1_process_querier_timers(struct mld_ifsoftc *);
130 static int mld_v1_transmit_report(struct in6_multi *, const int);
131 static void mld_v1_update_group(struct in6_multi *, const int);
132 static void mld_v2_cancel_link_timers(struct mld_ifsoftc *);
133 static void mld_v2_dispatch_general_query(struct mld_ifsoftc *);
134 static struct mbuf *
135 mld_v2_encap_report(struct ifnet *, struct mbuf *);
136 static int mld_v2_enqueue_filter_change(struct mbufq *,
137 struct in6_multi *);
138 static int mld_v2_enqueue_group_record(struct mbufq *,
139 struct in6_multi *, const int, const int, const int,
140 const int);
141 static int mld_v2_input_query(struct ifnet *, const struct ip6_hdr *,
142 struct mbuf *, struct mldv2_query *, const int, const int);
143 static int mld_v2_merge_state_changes(struct in6_multi *,
144 struct mbufq *);
145 static void mld_v2_process_group_timers(struct in6_multi_head *,
146 struct mbufq *, struct mbufq *,
147 struct in6_multi *, const int);
148 static int mld_v2_process_group_query(struct in6_multi *,
149 struct mld_ifsoftc *mli, int, struct mbuf *,
150 struct mldv2_query *, const int);
151 static int sysctl_mld_gsr(SYSCTL_HANDLER_ARGS);
152 static int sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS);
153
154 /*
155 * Normative references: RFC 2710, RFC 3590, RFC 3810.
156 *
157 * Locking:
158 * * The MLD subsystem lock ends up being system-wide for the moment,
159 * but could be per-VIMAGE later on.
160 * * The permitted lock order is: IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
161 * Any may be taken independently; if any are held at the same
162 * time, the above lock order must be followed.
163 * * IN6_MULTI_LOCK covers in_multi.
164 * * MLD_LOCK covers per-link state and any global variables in this file.
165 * * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
166 * per-link state iterators.
167 *
168 * XXX LOR PREVENTION
169 * A special case for IPv6 is the in6_setscope() routine. ip6_output()
170 * will not accept an ifp; it wants an embedded scope ID, unlike
171 * ip_output(), which happily takes the ifp given to it. The embedded
172 * scope ID is only used by MLD to select the outgoing interface.
173 *
174 * During interface attach and detach, MLD will take MLD_LOCK *after*
175 * the IF_AFDATA_LOCK.
176 * As in6_setscope() takes IF_AFDATA_LOCK then SCOPE_LOCK, we can't call
177 * it with MLD_LOCK held without triggering an LOR. A netisr with indirect
178 * dispatch could work around this, but we'd rather not do that, as it
179 * can introduce other races.
180 *
181 * As such, we exploit the fact that the scope ID is just the interface
182 * index, and embed it in the IPv6 destination address accordingly.
183 * This is potentially NOT VALID for MLDv1 reports, as they
184 * are always sent to the multicast group itself; as MLDv2
185 * reports are always sent to ff02::16, this is not an issue
186 * when MLDv2 is in use.
187 *
188 * This does not however eliminate the LOR when ip6_output() itself
189 * calls in6_setscope() internally whilst MLD_LOCK is held. This will
190 * trigger a LOR warning in WITNESS when the ifnet is detached.
191 *
192 * The right answer is probably to make IF_AFDATA_LOCK an rwlock, given
193 * how it's used across the network stack. Here we're simply exploiting
194 * the fact that MLD runs at a similar layer in the stack to scope6.c.
195 *
196 * VIMAGE:
197 * * Each in6_multi corresponds to an ifp, and each ifp corresponds
198 * to a vnet in ifp->if_vnet.
199 */
200 static struct mtx mld_mtx;
201 static MALLOC_DEFINE(M_MLD, "mld", "mld state");
202
203 #define MLD_EMBEDSCOPE(pin6, zoneid) \
204 if (IN6_IS_SCOPE_LINKLOCAL(pin6) || \
205 IN6_IS_ADDR_MC_INTFACELOCAL(pin6)) \
206 (pin6)->s6_addr16[1] = htons((zoneid) & 0xFFFF) \
207
208 /*
209 * VIMAGE-wide globals.
210 */
211 VNET_DEFINE_STATIC(struct timeval, mld_gsrdelay) = {10, 0};
212 VNET_DEFINE_STATIC(LIST_HEAD(, mld_ifsoftc), mli_head);
213 VNET_DEFINE_STATIC(int, interface_timers_running6);
214 VNET_DEFINE_STATIC(int, state_change_timers_running6);
215 VNET_DEFINE_STATIC(int, current_state_timers_running6);
216
217 #define V_mld_gsrdelay VNET(mld_gsrdelay)
218 #define V_mli_head VNET(mli_head)
219 #define V_interface_timers_running6 VNET(interface_timers_running6)
220 #define V_state_change_timers_running6 VNET(state_change_timers_running6)
221 #define V_current_state_timers_running6 VNET(current_state_timers_running6)
222
223 SYSCTL_DECL(_net_inet6); /* Note: Not in any common header. */
224
225 SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW, 0,
226 "IPv6 Multicast Listener Discovery");
227
228 /*
229 * Virtualized sysctls.
230 */
231 SYSCTL_PROC(_net_inet6_mld, OID_AUTO, gsrdelay,
232 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
233 &VNET_NAME(mld_gsrdelay.tv_sec), 0, sysctl_mld_gsr, "I",
234 "Rate limit for MLDv2 Group-and-Source queries in seconds");
235
236 /*
237 * Non-virtualized sysctls.
238 */
239 static SYSCTL_NODE(_net_inet6_mld, OID_AUTO, ifinfo,
240 CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_mld_ifinfo,
241 "Per-interface MLDv2 state");
242
243 static int mld_v1enable = 1;
244 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v1enable, CTLFLAG_RWTUN,
245 &mld_v1enable, 0, "Enable fallback to MLDv1");
246
247 static int mld_v2enable = 1;
248 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v2enable, CTLFLAG_RWTUN,
249 &mld_v2enable, 0, "Enable MLDv2");
250
251 static int mld_use_allow = 1;
252 SYSCTL_INT(_net_inet6_mld, OID_AUTO, use_allow, CTLFLAG_RWTUN,
253 &mld_use_allow, 0, "Use ALLOW/BLOCK for RFC 4604 SSM joins/leaves");
254
255 /*
256 * Packed Router Alert option structure declaration.
257 */
258 struct mld_raopt {
259 struct ip6_hbh hbh;
260 struct ip6_opt pad;
261 struct ip6_opt_router ra;
262 } __packed;
263
264 /*
265 * Router Alert hop-by-hop option header.
266 */
267 static struct mld_raopt mld_ra = {
268 .hbh = { 0, 0 },
269 .pad = { .ip6o_type = IP6OPT_PADN, 0 },
270 .ra = {
271 .ip6or_type = IP6OPT_ROUTER_ALERT,
272 .ip6or_len = IP6OPT_RTALERT_LEN - 2,
273 .ip6or_value[0] = ((IP6OPT_RTALERT_MLD >> 8) & 0xFF),
274 .ip6or_value[1] = (IP6OPT_RTALERT_MLD & 0xFF)
275 }
276 };
277 static struct ip6_pktopts mld_po;
278
279 static __inline void
mld_save_context(struct mbuf * m,struct ifnet * ifp)280 mld_save_context(struct mbuf *m, struct ifnet *ifp)
281 {
282
283 #ifdef VIMAGE
284 m->m_pkthdr.PH_loc.ptr = ifp->if_vnet;
285 #endif /* VIMAGE */
286 m->m_pkthdr.rcvif = ifp;
287 m->m_pkthdr.flowid = ifp->if_index;
288 }
289
290 static __inline void
mld_scrub_context(struct mbuf * m)291 mld_scrub_context(struct mbuf *m)
292 {
293
294 m->m_pkthdr.PH_loc.ptr = NULL;
295 m->m_pkthdr.flowid = 0;
296 }
297
298 /*
299 * Restore context from a queued output chain.
300 * Return saved ifindex.
301 *
302 * VIMAGE: The assertion is there to make sure that we
303 * actually called CURVNET_SET() with what's in the mbuf chain.
304 */
305 static __inline uint32_t
mld_restore_context(struct mbuf * m)306 mld_restore_context(struct mbuf *m)
307 {
308
309 #if defined(VIMAGE) && defined(INVARIANTS)
310 KASSERT(curvnet == m->m_pkthdr.PH_loc.ptr,
311 ("%s: called when curvnet was not restored: cuvnet %p m ptr %p",
312 __func__, curvnet, m->m_pkthdr.PH_loc.ptr));
313 #endif
314 return (m->m_pkthdr.flowid);
315 }
316
317 /*
318 * Retrieve or set threshold between group-source queries in seconds.
319 *
320 * VIMAGE: Assume curvnet set by caller.
321 * SMPng: NOTE: Serialized by MLD lock.
322 */
323 static int
sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)324 sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
325 {
326 int error;
327 int i;
328
329 error = sysctl_wire_old_buffer(req, sizeof(int));
330 if (error)
331 return (error);
332
333 MLD_LOCK();
334
335 i = V_mld_gsrdelay.tv_sec;
336
337 error = sysctl_handle_int(oidp, &i, 0, req);
338 if (error || !req->newptr)
339 goto out_locked;
340
341 if (i < -1 || i >= 60) {
342 error = EINVAL;
343 goto out_locked;
344 }
345
346 CTR2(KTR_MLD, "change mld_gsrdelay from %d to %d",
347 V_mld_gsrdelay.tv_sec, i);
348 V_mld_gsrdelay.tv_sec = i;
349
350 out_locked:
351 MLD_UNLOCK();
352 return (error);
353 }
354
355 /*
356 * Expose struct mld_ifsoftc to userland, keyed by ifindex.
357 * For use by ifmcstat(8).
358 *
359 * SMPng: NOTE: Does an unlocked ifindex space read.
360 * VIMAGE: Assume curvnet set by caller. The node handler itself
361 * is not directly virtualized.
362 */
363 static int
sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)364 sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
365 {
366 int *name;
367 int error;
368 u_int namelen;
369 struct ifnet *ifp;
370 struct mld_ifsoftc *mli;
371
372 name = (int *)arg1;
373 namelen = arg2;
374
375 if (req->newptr != NULL)
376 return (EPERM);
377
378 if (namelen != 1)
379 return (EINVAL);
380
381 error = sysctl_wire_old_buffer(req, sizeof(struct mld_ifinfo));
382 if (error)
383 return (error);
384
385 IN6_MULTI_LOCK();
386 IN6_MULTI_LIST_LOCK();
387 MLD_LOCK();
388
389 if (name[0] <= 0 || name[0] > V_if_index) {
390 error = ENOENT;
391 goto out_locked;
392 }
393
394 error = ENOENT;
395
396 ifp = ifnet_byindex(name[0]);
397 if (ifp == NULL)
398 goto out_locked;
399
400 LIST_FOREACH(mli, &V_mli_head, mli_link) {
401 if (ifp == mli->mli_ifp) {
402 struct mld_ifinfo info;
403
404 info.mli_version = mli->mli_version;
405 info.mli_v1_timer = mli->mli_v1_timer;
406 info.mli_v2_timer = mli->mli_v2_timer;
407 info.mli_flags = mli->mli_flags;
408 info.mli_rv = mli->mli_rv;
409 info.mli_qi = mli->mli_qi;
410 info.mli_qri = mli->mli_qri;
411 info.mli_uri = mli->mli_uri;
412 error = SYSCTL_OUT(req, &info, sizeof(info));
413 break;
414 }
415 }
416
417 out_locked:
418 MLD_UNLOCK();
419 IN6_MULTI_LIST_UNLOCK();
420 IN6_MULTI_UNLOCK();
421 return (error);
422 }
423
424 /*
425 * Dispatch an entire queue of pending packet chains.
426 * VIMAGE: Assumes the vnet pointer has been set.
427 */
428 static void
mld_dispatch_queue(struct mbufq * mq,int limit)429 mld_dispatch_queue(struct mbufq *mq, int limit)
430 {
431 struct mbuf *m;
432
433 while ((m = mbufq_dequeue(mq)) != NULL) {
434 CTR3(KTR_MLD, "%s: dispatch %p from %p", __func__, mq, m);
435 mld_dispatch_packet(m);
436 if (--limit == 0)
437 break;
438 }
439 }
440
441 /*
442 * Filter outgoing MLD report state by group.
443 *
444 * Reports are ALWAYS suppressed for ALL-HOSTS (ff02::1)
445 * and node-local addresses. However, kernel and socket consumers
446 * always embed the KAME scope ID in the address provided, so strip it
447 * when performing comparison.
448 * Note: This is not the same as the *multicast* scope.
449 *
450 * Return zero if the given group is one for which MLD reports
451 * should be suppressed, or non-zero if reports should be issued.
452 */
453 static __inline int
mld_is_addr_reported(const struct in6_addr * addr)454 mld_is_addr_reported(const struct in6_addr *addr)
455 {
456
457 KASSERT(IN6_IS_ADDR_MULTICAST(addr), ("%s: not multicast", __func__));
458
459 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_NODELOCAL)
460 return (0);
461
462 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_LINKLOCAL) {
463 struct in6_addr tmp = *addr;
464 in6_clearscope(&tmp);
465 if (IN6_ARE_ADDR_EQUAL(&tmp, &in6addr_linklocal_allnodes))
466 return (0);
467 }
468
469 return (1);
470 }
471
472 /*
473 * Attach MLD when PF_INET6 is attached to an interface.
474 *
475 * SMPng: Normally called with IF_AFDATA_LOCK held.
476 */
477 struct mld_ifsoftc *
mld_domifattach(struct ifnet * ifp)478 mld_domifattach(struct ifnet *ifp)
479 {
480 struct mld_ifsoftc *mli;
481
482 CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
483 __func__, ifp, if_name(ifp));
484
485 MLD_LOCK();
486
487 mli = mli_alloc_locked(ifp);
488 if (!(ifp->if_flags & IFF_MULTICAST))
489 mli->mli_flags |= MLIF_SILENT;
490 if (mld_use_allow)
491 mli->mli_flags |= MLIF_USEALLOW;
492
493 MLD_UNLOCK();
494
495 return (mli);
496 }
497
498 /*
499 * VIMAGE: assume curvnet set by caller.
500 */
501 static struct mld_ifsoftc *
mli_alloc_locked(struct ifnet * ifp)502 mli_alloc_locked(/*const*/ struct ifnet *ifp)
503 {
504 struct mld_ifsoftc *mli;
505
506 MLD_LOCK_ASSERT();
507
508 mli = malloc(sizeof(struct mld_ifsoftc), M_MLD, M_NOWAIT|M_ZERO);
509 if (mli == NULL)
510 goto out;
511
512 mli->mli_ifp = ifp;
513 mli->mli_version = MLD_VERSION_2;
514 mli->mli_flags = 0;
515 mli->mli_rv = MLD_RV_INIT;
516 mli->mli_qi = MLD_QI_INIT;
517 mli->mli_qri = MLD_QRI_INIT;
518 mli->mli_uri = MLD_URI_INIT;
519 mbufq_init(&mli->mli_gq, MLD_MAX_RESPONSE_PACKETS);
520
521 LIST_INSERT_HEAD(&V_mli_head, mli, mli_link);
522
523 CTR2(KTR_MLD, "allocate mld_ifsoftc for ifp %p(%s)",
524 ifp, if_name(ifp));
525
526 out:
527 return (mli);
528 }
529
530 /*
531 * Hook for ifdetach.
532 *
533 * NOTE: Some finalization tasks need to run before the protocol domain
534 * is detached, but also before the link layer does its cleanup.
535 * Run before link-layer cleanup; cleanup groups, but do not free MLD state.
536 *
537 * SMPng: Caller must hold IN6_MULTI_LOCK().
538 * Must take IF_ADDR_LOCK() to cover if_multiaddrs iterator.
539 * XXX This routine is also bitten by unlocked ifma_protospec access.
540 */
541 void
mld_ifdetach(struct ifnet * ifp,struct in6_multi_head * inmh)542 mld_ifdetach(struct ifnet *ifp, struct in6_multi_head *inmh)
543 {
544 struct epoch_tracker et;
545 struct mld_ifsoftc *mli;
546 struct ifmultiaddr *ifma;
547 struct in6_multi *inm;
548
549 CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp,
550 if_name(ifp));
551
552 IN6_MULTI_LIST_LOCK_ASSERT();
553 MLD_LOCK();
554
555 mli = MLD_IFINFO(ifp);
556 IF_ADDR_WLOCK(ifp);
557 /*
558 * Extract list of in6_multi associated with the detaching ifp
559 * which the PF_INET6 layer is about to release.
560 */
561 NET_EPOCH_ENTER_ET(et);
562 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
563 inm = in6m_ifmultiaddr_get_inm(ifma);
564 if (inm == NULL)
565 continue;
566 in6m_disconnect_locked(inmh, inm);
567
568 if (mli->mli_version == MLD_VERSION_2) {
569 in6m_clear_recorded(inm);
570
571 /*
572 * We need to release the final reference held
573 * for issuing the INCLUDE {}.
574 */
575 if (inm->in6m_state == MLD_LEAVING_MEMBER) {
576 inm->in6m_state = MLD_NOT_MEMBER;
577 in6m_rele_locked(inmh, inm);
578 }
579 }
580 }
581 NET_EPOCH_EXIT_ET(et);
582 IF_ADDR_WUNLOCK(ifp);
583 MLD_UNLOCK();
584 }
585
586 /*
587 * Hook for domifdetach.
588 * Runs after link-layer cleanup; free MLD state.
589 *
590 * SMPng: Normally called with IF_AFDATA_LOCK held.
591 */
592 void
mld_domifdetach(struct ifnet * ifp)593 mld_domifdetach(struct ifnet *ifp)
594 {
595
596 CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
597 __func__, ifp, if_name(ifp));
598
599 MLD_LOCK();
600 mli_delete_locked(ifp);
601 MLD_UNLOCK();
602 }
603
604 static void
mli_delete_locked(const struct ifnet * ifp)605 mli_delete_locked(const struct ifnet *ifp)
606 {
607 struct mld_ifsoftc *mli, *tmli;
608
609 CTR3(KTR_MLD, "%s: freeing mld_ifsoftc for ifp %p(%s)",
610 __func__, ifp, if_name(ifp));
611
612 MLD_LOCK_ASSERT();
613
614 LIST_FOREACH_SAFE(mli, &V_mli_head, mli_link, tmli) {
615 if (mli->mli_ifp == ifp) {
616 /*
617 * Free deferred General Query responses.
618 */
619 mbufq_drain(&mli->mli_gq);
620
621 LIST_REMOVE(mli, mli_link);
622
623 free(mli, M_MLD);
624 return;
625 }
626 }
627 }
628
629 /*
630 * Process a received MLDv1 general or address-specific query.
631 * Assumes that the query header has been pulled up to sizeof(mld_hdr).
632 *
633 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
634 * mld_addr. This is OK as we own the mbuf chain.
635 */
636 static int
mld_v1_input_query(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)637 mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
638 /*const*/ struct mld_hdr *mld)
639 {
640 struct ifmultiaddr *ifma;
641 struct mld_ifsoftc *mli;
642 struct in6_multi *inm;
643 int is_general_query;
644 uint16_t timer;
645 #ifdef KTR
646 char ip6tbuf[INET6_ADDRSTRLEN];
647 #endif
648
649 is_general_query = 0;
650
651 if (!mld_v1enable) {
652 CTR3(KTR_MLD, "ignore v1 query %s on ifp %p(%s)",
653 ip6_sprintf(ip6tbuf, &mld->mld_addr),
654 ifp, if_name(ifp));
655 return (0);
656 }
657
658 /*
659 * RFC3810 Section 6.2: MLD queries must originate from
660 * a router's link-local address.
661 */
662 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
663 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
664 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
665 ifp, if_name(ifp));
666 return (0);
667 }
668
669 /*
670 * Do address field validation upfront before we accept
671 * the query.
672 */
673 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
674 /*
675 * MLDv1 General Query.
676 * If this was not sent to the all-nodes group, ignore it.
677 */
678 struct in6_addr dst;
679
680 dst = ip6->ip6_dst;
681 in6_clearscope(&dst);
682 if (!IN6_ARE_ADDR_EQUAL(&dst, &in6addr_linklocal_allnodes))
683 return (EINVAL);
684 is_general_query = 1;
685 } else {
686 /*
687 * Embed scope ID of receiving interface in MLD query for
688 * lookup whilst we don't hold other locks.
689 */
690 in6_setscope(&mld->mld_addr, ifp, NULL);
691 }
692
693 IN6_MULTI_LIST_LOCK();
694 MLD_LOCK();
695
696 /*
697 * Switch to MLDv1 host compatibility mode.
698 */
699 mli = MLD_IFINFO(ifp);
700 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
701 mld_set_version(mli, MLD_VERSION_1);
702
703 timer = (ntohs(mld->mld_maxdelay) * PR_FASTHZ) / MLD_TIMER_SCALE;
704 if (timer == 0)
705 timer = 1;
706
707 IF_ADDR_RLOCK(ifp);
708 if (is_general_query) {
709 /*
710 * For each reporting group joined on this
711 * interface, kick the report timer.
712 */
713 CTR2(KTR_MLD, "process v1 general query on ifp %p(%s)",
714 ifp, if_name(ifp));
715 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
716 inm = in6m_ifmultiaddr_get_inm(ifma);
717 if (inm == NULL)
718 continue;
719 mld_v1_update_group(inm, timer);
720 }
721 } else {
722 /*
723 * MLDv1 Group-Specific Query.
724 * If this is a group-specific MLDv1 query, we need only
725 * look up the single group to process it.
726 */
727 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
728 if (inm != NULL) {
729 CTR3(KTR_MLD, "process v1 query %s on ifp %p(%s)",
730 ip6_sprintf(ip6tbuf, &mld->mld_addr),
731 ifp, if_name(ifp));
732 mld_v1_update_group(inm, timer);
733 }
734 /* XXX Clear embedded scope ID as userland won't expect it. */
735 in6_clearscope(&mld->mld_addr);
736 }
737
738 IF_ADDR_RUNLOCK(ifp);
739 MLD_UNLOCK();
740 IN6_MULTI_LIST_UNLOCK();
741
742 return (0);
743 }
744
745 /*
746 * Update the report timer on a group in response to an MLDv1 query.
747 *
748 * If we are becoming the reporting member for this group, start the timer.
749 * If we already are the reporting member for this group, and timer is
750 * below the threshold, reset it.
751 *
752 * We may be updating the group for the first time since we switched
753 * to MLDv2. If we are, then we must clear any recorded source lists,
754 * and transition to REPORTING state; the group timer is overloaded
755 * for group and group-source query responses.
756 *
757 * Unlike MLDv2, the delay per group should be jittered
758 * to avoid bursts of MLDv1 reports.
759 */
760 static void
mld_v1_update_group(struct in6_multi * inm,const int timer)761 mld_v1_update_group(struct in6_multi *inm, const int timer)
762 {
763 #ifdef KTR
764 char ip6tbuf[INET6_ADDRSTRLEN];
765 #endif
766
767 CTR4(KTR_MLD, "%s: %s/%s timer=%d", __func__,
768 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
769 if_name(inm->in6m_ifp), timer);
770
771 IN6_MULTI_LIST_LOCK_ASSERT();
772
773 switch (inm->in6m_state) {
774 case MLD_NOT_MEMBER:
775 case MLD_SILENT_MEMBER:
776 break;
777 case MLD_REPORTING_MEMBER:
778 if (inm->in6m_timer != 0 &&
779 inm->in6m_timer <= timer) {
780 CTR1(KTR_MLD, "%s: REPORTING and timer running, "
781 "skipping.", __func__);
782 break;
783 }
784 /* FALLTHROUGH */
785 case MLD_SG_QUERY_PENDING_MEMBER:
786 case MLD_G_QUERY_PENDING_MEMBER:
787 case MLD_IDLE_MEMBER:
788 case MLD_LAZY_MEMBER:
789 case MLD_AWAKENING_MEMBER:
790 CTR1(KTR_MLD, "%s: ->REPORTING", __func__);
791 inm->in6m_state = MLD_REPORTING_MEMBER;
792 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
793 V_current_state_timers_running6 = 1;
794 break;
795 case MLD_SLEEPING_MEMBER:
796 CTR1(KTR_MLD, "%s: ->AWAKENING", __func__);
797 inm->in6m_state = MLD_AWAKENING_MEMBER;
798 break;
799 case MLD_LEAVING_MEMBER:
800 break;
801 }
802 }
803
804 /*
805 * Process a received MLDv2 general, group-specific or
806 * group-and-source-specific query.
807 *
808 * Assumes that mld points to a struct mldv2_query which is stored in
809 * contiguous memory.
810 *
811 * Return 0 if successful, otherwise an appropriate error code is returned.
812 */
813 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)814 mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
815 struct mbuf *m, struct mldv2_query *mld, const int off, const int icmp6len)
816 {
817 struct mld_ifsoftc *mli;
818 struct in6_multi *inm;
819 uint32_t maxdelay, nsrc, qqi;
820 int is_general_query;
821 uint16_t timer;
822 uint8_t qrv;
823 #ifdef KTR
824 char ip6tbuf[INET6_ADDRSTRLEN];
825 #endif
826
827 if (!mld_v2enable) {
828 CTR3(KTR_MLD, "ignore v2 query src %s on ifp %p(%s)",
829 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
830 ifp, if_name(ifp));
831 return (0);
832 }
833
834 /*
835 * RFC3810 Section 6.2: MLD queries must originate from
836 * a router's link-local address.
837 */
838 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
839 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
840 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
841 ifp, if_name(ifp));
842 return (0);
843 }
844
845 is_general_query = 0;
846
847 CTR2(KTR_MLD, "input v2 query on ifp %p(%s)", ifp, if_name(ifp));
848
849 maxdelay = ntohs(mld->mld_maxdelay); /* in 1/10ths of a second */
850 if (maxdelay >= 32768) {
851 maxdelay = (MLD_MRC_MANT(maxdelay) | 0x1000) <<
852 (MLD_MRC_EXP(maxdelay) + 3);
853 }
854 timer = (maxdelay * PR_FASTHZ) / MLD_TIMER_SCALE;
855 if (timer == 0)
856 timer = 1;
857
858 qrv = MLD_QRV(mld->mld_misc);
859 if (qrv < 2) {
860 CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
861 qrv, MLD_RV_INIT);
862 qrv = MLD_RV_INIT;
863 }
864
865 qqi = mld->mld_qqi;
866 if (qqi >= 128) {
867 qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
868 (MLD_QQIC_EXP(mld->mld_qqi) + 3);
869 }
870
871 nsrc = ntohs(mld->mld_numsrc);
872 if (nsrc > MLD_MAX_GS_SOURCES)
873 return (EMSGSIZE);
874 if (icmp6len < sizeof(struct mldv2_query) +
875 (nsrc * sizeof(struct in6_addr)))
876 return (EMSGSIZE);
877
878 /*
879 * Do further input validation upfront to avoid resetting timers
880 * should we need to discard this query.
881 */
882 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
883 /*
884 * A general query with a source list has undefined
885 * behaviour; discard it.
886 */
887 if (nsrc > 0)
888 return (EINVAL);
889 is_general_query = 1;
890 } else {
891 /*
892 * Embed scope ID of receiving interface in MLD query for
893 * lookup whilst we don't hold other locks (due to KAME
894 * locking lameness). We own this mbuf chain just now.
895 */
896 in6_setscope(&mld->mld_addr, ifp, NULL);
897 }
898
899 IN6_MULTI_LIST_LOCK();
900 MLD_LOCK();
901
902 mli = MLD_IFINFO(ifp);
903 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
904
905 /*
906 * Discard the v2 query if we're in Compatibility Mode.
907 * The RFC is pretty clear that hosts need to stay in MLDv1 mode
908 * until the Old Version Querier Present timer expires.
909 */
910 if (mli->mli_version != MLD_VERSION_2)
911 goto out_locked;
912
913 mld_set_version(mli, MLD_VERSION_2);
914 mli->mli_rv = qrv;
915 mli->mli_qi = qqi;
916 mli->mli_qri = maxdelay;
917
918 CTR4(KTR_MLD, "%s: qrv %d qi %d maxdelay %d", __func__, qrv, qqi,
919 maxdelay);
920
921 if (is_general_query) {
922 /*
923 * MLDv2 General Query.
924 *
925 * Schedule a current-state report on this ifp for
926 * all groups, possibly containing source lists.
927 *
928 * If there is a pending General Query response
929 * scheduled earlier than the selected delay, do
930 * not schedule any other reports.
931 * Otherwise, reset the interface timer.
932 */
933 CTR2(KTR_MLD, "process v2 general query on ifp %p(%s)",
934 ifp, if_name(ifp));
935 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer) {
936 mli->mli_v2_timer = MLD_RANDOM_DELAY(timer);
937 V_interface_timers_running6 = 1;
938 }
939 } else {
940 /*
941 * MLDv2 Group-specific or Group-and-source-specific Query.
942 *
943 * Group-source-specific queries are throttled on
944 * a per-group basis to defeat denial-of-service attempts.
945 * Queries for groups we are not a member of on this
946 * link are simply ignored.
947 */
948 IF_ADDR_RLOCK(ifp);
949 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
950 if (inm == NULL) {
951 IF_ADDR_RUNLOCK(ifp);
952 goto out_locked;
953 }
954 if (nsrc > 0) {
955 if (!ratecheck(&inm->in6m_lastgsrtv,
956 &V_mld_gsrdelay)) {
957 CTR1(KTR_MLD, "%s: GS query throttled.",
958 __func__);
959 IF_ADDR_RUNLOCK(ifp);
960 goto out_locked;
961 }
962 }
963 CTR2(KTR_MLD, "process v2 group query on ifp %p(%s)",
964 ifp, if_name(ifp));
965 /*
966 * If there is a pending General Query response
967 * scheduled sooner than the selected delay, no
968 * further report need be scheduled.
969 * Otherwise, prepare to respond to the
970 * group-specific or group-and-source query.
971 */
972 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer)
973 mld_v2_process_group_query(inm, mli, timer, m, mld, off);
974
975 /* XXX Clear embedded scope ID as userland won't expect it. */
976 in6_clearscope(&mld->mld_addr);
977 IF_ADDR_RUNLOCK(ifp);
978 }
979
980 out_locked:
981 MLD_UNLOCK();
982 IN6_MULTI_LIST_UNLOCK();
983
984 return (0);
985 }
986
987 /*
988 * Process a received MLDv2 group-specific or group-and-source-specific
989 * query.
990 * Return <0 if any error occurred. Currently this is ignored.
991 */
992 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)993 mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifsoftc *mli,
994 int timer, struct mbuf *m0, struct mldv2_query *mld, const int off)
995 {
996 int retval;
997 uint16_t nsrc;
998
999 IN6_MULTI_LIST_LOCK_ASSERT();
1000 MLD_LOCK_ASSERT();
1001
1002 retval = 0;
1003
1004 switch (inm->in6m_state) {
1005 case MLD_NOT_MEMBER:
1006 case MLD_SILENT_MEMBER:
1007 case MLD_SLEEPING_MEMBER:
1008 case MLD_LAZY_MEMBER:
1009 case MLD_AWAKENING_MEMBER:
1010 case MLD_IDLE_MEMBER:
1011 case MLD_LEAVING_MEMBER:
1012 return (retval);
1013 break;
1014 case MLD_REPORTING_MEMBER:
1015 case MLD_G_QUERY_PENDING_MEMBER:
1016 case MLD_SG_QUERY_PENDING_MEMBER:
1017 break;
1018 }
1019
1020 nsrc = ntohs(mld->mld_numsrc);
1021
1022 /* Length should be checked by calling function. */
1023 KASSERT((m0->m_flags & M_PKTHDR) == 0 ||
1024 m0->m_pkthdr.len >= off + sizeof(struct mldv2_query) +
1025 nsrc * sizeof(struct in6_addr),
1026 ("mldv2 packet is too short: (%d bytes < %zd bytes, m=%p)",
1027 m0->m_pkthdr.len, off + sizeof(struct mldv2_query) +
1028 nsrc * sizeof(struct in6_addr), m0));
1029
1030
1031 /*
1032 * Deal with group-specific queries upfront.
1033 * If any group query is already pending, purge any recorded
1034 * source-list state if it exists, and schedule a query response
1035 * for this group-specific query.
1036 */
1037 if (nsrc == 0) {
1038 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
1039 inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER) {
1040 in6m_clear_recorded(inm);
1041 timer = min(inm->in6m_timer, timer);
1042 }
1043 inm->in6m_state = MLD_G_QUERY_PENDING_MEMBER;
1044 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1045 V_current_state_timers_running6 = 1;
1046 return (retval);
1047 }
1048
1049 /*
1050 * Deal with the case where a group-and-source-specific query has
1051 * been received but a group-specific query is already pending.
1052 */
1053 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER) {
1054 timer = min(inm->in6m_timer, timer);
1055 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1056 V_current_state_timers_running6 = 1;
1057 return (retval);
1058 }
1059
1060 /*
1061 * Finally, deal with the case where a group-and-source-specific
1062 * query has been received, where a response to a previous g-s-r
1063 * query exists, or none exists.
1064 * In this case, we need to parse the source-list which the Querier
1065 * has provided us with and check if we have any source list filter
1066 * entries at T1 for these sources. If we do not, there is no need
1067 * schedule a report and the query may be dropped.
1068 * If we do, we must record them and schedule a current-state
1069 * report for those sources.
1070 */
1071 if (inm->in6m_nsrc > 0) {
1072 struct in6_addr srcaddr;
1073 int i, nrecorded;
1074 int soff;
1075
1076 soff = off + sizeof(struct mldv2_query);
1077 nrecorded = 0;
1078 for (i = 0; i < nsrc; i++) {
1079 m_copydata(m0, soff, sizeof(struct in6_addr),
1080 (caddr_t)&srcaddr);
1081 retval = in6m_record_source(inm, &srcaddr);
1082 if (retval < 0)
1083 break;
1084 nrecorded += retval;
1085 soff += sizeof(struct in6_addr);
1086 }
1087 if (nrecorded > 0) {
1088 CTR1(KTR_MLD,
1089 "%s: schedule response to SG query", __func__);
1090 inm->in6m_state = MLD_SG_QUERY_PENDING_MEMBER;
1091 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1092 V_current_state_timers_running6 = 1;
1093 }
1094 }
1095
1096 return (retval);
1097 }
1098
1099 /*
1100 * Process a received MLDv1 host membership report.
1101 * Assumes mld points to mld_hdr in pulled up mbuf chain.
1102 *
1103 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
1104 * mld_addr. This is OK as we own the mbuf chain.
1105 */
1106 static int
mld_v1_input_report(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)1107 mld_v1_input_report(struct ifnet *ifp, const struct ip6_hdr *ip6,
1108 /*const*/ struct mld_hdr *mld)
1109 {
1110 struct in6_addr src, dst;
1111 struct in6_ifaddr *ia;
1112 struct in6_multi *inm;
1113 #ifdef KTR
1114 char ip6tbuf[INET6_ADDRSTRLEN];
1115 #endif
1116
1117 if (!mld_v1enable) {
1118 CTR3(KTR_MLD, "ignore v1 report %s on ifp %p(%s)",
1119 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1120 ifp, if_name(ifp));
1121 return (0);
1122 }
1123
1124 if (ifp->if_flags & IFF_LOOPBACK)
1125 return (0);
1126
1127 /*
1128 * MLDv1 reports must originate from a host's link-local address,
1129 * or the unspecified address (when booting).
1130 */
1131 src = ip6->ip6_src;
1132 in6_clearscope(&src);
1133 if (!IN6_IS_SCOPE_LINKLOCAL(&src) && !IN6_IS_ADDR_UNSPECIFIED(&src)) {
1134 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
1135 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
1136 ifp, if_name(ifp));
1137 return (EINVAL);
1138 }
1139
1140 /*
1141 * RFC2710 Section 4: MLDv1 reports must pertain to a multicast
1142 * group, and must be directed to the group itself.
1143 */
1144 dst = ip6->ip6_dst;
1145 in6_clearscope(&dst);
1146 if (!IN6_IS_ADDR_MULTICAST(&mld->mld_addr) ||
1147 !IN6_ARE_ADDR_EQUAL(&mld->mld_addr, &dst)) {
1148 CTR3(KTR_MLD, "ignore v1 query dst %s on ifp %p(%s)",
1149 ip6_sprintf(ip6tbuf, &ip6->ip6_dst),
1150 ifp, if_name(ifp));
1151 return (EINVAL);
1152 }
1153
1154 /*
1155 * Make sure we don't hear our own membership report, as fast
1156 * leave requires knowing that we are the only member of a
1157 * group. Assume we used the link-local address if available,
1158 * otherwise look for ::.
1159 *
1160 * XXX Note that scope ID comparison is needed for the address
1161 * returned by in6ifa_ifpforlinklocal(), but SHOULD NOT be
1162 * performed for the on-wire address.
1163 */
1164 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1165 if ((ia && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, IA6_IN6(ia))) ||
1166 (ia == NULL && IN6_IS_ADDR_UNSPECIFIED(&src))) {
1167 if (ia != NULL)
1168 ifa_free(&ia->ia_ifa);
1169 return (0);
1170 }
1171 if (ia != NULL)
1172 ifa_free(&ia->ia_ifa);
1173
1174 CTR3(KTR_MLD, "process v1 report %s on ifp %p(%s)",
1175 ip6_sprintf(ip6tbuf, &mld->mld_addr), ifp, if_name(ifp));
1176
1177 /*
1178 * Embed scope ID of receiving interface in MLD query for lookup
1179 * whilst we don't hold other locks (due to KAME locking lameness).
1180 */
1181 if (!IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr))
1182 in6_setscope(&mld->mld_addr, ifp, NULL);
1183
1184 IN6_MULTI_LIST_LOCK();
1185 MLD_LOCK();
1186 IF_ADDR_RLOCK(ifp);
1187
1188 /*
1189 * MLDv1 report suppression.
1190 * If we are a member of this group, and our membership should be
1191 * reported, and our group timer is pending or about to be reset,
1192 * stop our group timer by transitioning to the 'lazy' state.
1193 */
1194 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
1195 if (inm != NULL) {
1196 struct mld_ifsoftc *mli;
1197
1198 mli = inm->in6m_mli;
1199 KASSERT(mli != NULL,
1200 ("%s: no mli for ifp %p", __func__, ifp));
1201
1202 /*
1203 * If we are in MLDv2 host mode, do not allow the
1204 * other host's MLDv1 report to suppress our reports.
1205 */
1206 if (mli->mli_version == MLD_VERSION_2)
1207 goto out_locked;
1208
1209 inm->in6m_timer = 0;
1210
1211 switch (inm->in6m_state) {
1212 case MLD_NOT_MEMBER:
1213 case MLD_SILENT_MEMBER:
1214 case MLD_SLEEPING_MEMBER:
1215 break;
1216 case MLD_REPORTING_MEMBER:
1217 case MLD_IDLE_MEMBER:
1218 case MLD_AWAKENING_MEMBER:
1219 CTR3(KTR_MLD,
1220 "report suppressed for %s on ifp %p(%s)",
1221 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1222 ifp, if_name(ifp));
1223 case MLD_LAZY_MEMBER:
1224 inm->in6m_state = MLD_LAZY_MEMBER;
1225 break;
1226 case MLD_G_QUERY_PENDING_MEMBER:
1227 case MLD_SG_QUERY_PENDING_MEMBER:
1228 case MLD_LEAVING_MEMBER:
1229 break;
1230 }
1231 }
1232
1233 out_locked:
1234 IF_ADDR_RUNLOCK(ifp);
1235 MLD_UNLOCK();
1236 IN6_MULTI_LIST_UNLOCK();
1237
1238 /* XXX Clear embedded scope ID as userland won't expect it. */
1239 in6_clearscope(&mld->mld_addr);
1240
1241 return (0);
1242 }
1243
1244 /*
1245 * MLD input path.
1246 *
1247 * Assume query messages which fit in a single ICMPv6 message header
1248 * have been pulled up.
1249 * Assume that userland will want to see the message, even if it
1250 * otherwise fails kernel input validation; do not free it.
1251 * Pullup may however free the mbuf chain m if it fails.
1252 *
1253 * Return IPPROTO_DONE if we freed m. Otherwise, return 0.
1254 */
1255 int
mld_input(struct mbuf ** mp,int off,int icmp6len)1256 mld_input(struct mbuf **mp, int off, int icmp6len)
1257 {
1258 struct ifnet *ifp;
1259 struct ip6_hdr *ip6;
1260 struct mbuf *m;
1261 struct mld_hdr *mld;
1262 int mldlen;
1263
1264 m = *mp;
1265 CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
1266
1267 ifp = m->m_pkthdr.rcvif;
1268
1269 /* Pullup to appropriate size. */
1270 if (m->m_len < off + sizeof(*mld)) {
1271 m = m_pullup(m, off + sizeof(*mld));
1272 if (m == NULL) {
1273 ICMP6STAT_INC(icp6s_badlen);
1274 return (IPPROTO_DONE);
1275 }
1276 }
1277 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1278 if (mld->mld_type == MLD_LISTENER_QUERY &&
1279 icmp6len >= sizeof(struct mldv2_query)) {
1280 mldlen = sizeof(struct mldv2_query);
1281 } else {
1282 mldlen = sizeof(struct mld_hdr);
1283 }
1284 if (m->m_len < off + mldlen) {
1285 m = m_pullup(m, off + mldlen);
1286 if (m == NULL) {
1287 ICMP6STAT_INC(icp6s_badlen);
1288 return (IPPROTO_DONE);
1289 }
1290 }
1291 *mp = m;
1292 ip6 = mtod(m, struct ip6_hdr *);
1293 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1294
1295 /*
1296 * Userland needs to see all of this traffic for implementing
1297 * the endpoint discovery portion of multicast routing.
1298 */
1299 switch (mld->mld_type) {
1300 case MLD_LISTENER_QUERY:
1301 icmp6_ifstat_inc(ifp, ifs6_in_mldquery);
1302 if (icmp6len == sizeof(struct mld_hdr)) {
1303 if (mld_v1_input_query(ifp, ip6, mld) != 0)
1304 return (0);
1305 } else if (icmp6len >= sizeof(struct mldv2_query)) {
1306 if (mld_v2_input_query(ifp, ip6, m,
1307 (struct mldv2_query *)mld, off, icmp6len) != 0)
1308 return (0);
1309 }
1310 break;
1311 case MLD_LISTENER_REPORT:
1312 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1313 if (mld_v1_input_report(ifp, ip6, mld) != 0)
1314 return (0);
1315 break;
1316 case MLDV2_LISTENER_REPORT:
1317 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1318 break;
1319 case MLD_LISTENER_DONE:
1320 icmp6_ifstat_inc(ifp, ifs6_in_mlddone);
1321 break;
1322 default:
1323 break;
1324 }
1325
1326 return (0);
1327 }
1328
1329 /*
1330 * Fast timeout handler (global).
1331 * VIMAGE: Timeout handlers are expected to service all vimages.
1332 */
1333 void
mld_fasttimo(void)1334 mld_fasttimo(void)
1335 {
1336 struct in6_multi_head inmh;
1337 VNET_ITERATOR_DECL(vnet_iter);
1338
1339 SLIST_INIT(&inmh);
1340
1341 VNET_LIST_RLOCK_NOSLEEP();
1342 VNET_FOREACH(vnet_iter) {
1343 CURVNET_SET(vnet_iter);
1344 mld_fasttimo_vnet(&inmh);
1345 CURVNET_RESTORE();
1346 }
1347 VNET_LIST_RUNLOCK_NOSLEEP();
1348 in6m_release_list_deferred(&inmh);
1349 }
1350
1351 /*
1352 * Fast timeout handler (per-vnet).
1353 *
1354 * VIMAGE: Assume caller has set up our curvnet.
1355 */
1356 static void
mld_fasttimo_vnet(struct in6_multi_head * inmh)1357 mld_fasttimo_vnet(struct in6_multi_head *inmh)
1358 {
1359 struct epoch_tracker et;
1360 struct mbufq scq; /* State-change packets */
1361 struct mbufq qrq; /* Query response packets */
1362 struct ifnet *ifp;
1363 struct mld_ifsoftc *mli;
1364 struct ifmultiaddr *ifma;
1365 struct in6_multi *inm;
1366 int uri_fasthz;
1367
1368 uri_fasthz = 0;
1369
1370 /*
1371 * Quick check to see if any work needs to be done, in order to
1372 * minimize the overhead of fasttimo processing.
1373 * SMPng: XXX Unlocked reads.
1374 */
1375 if (!V_current_state_timers_running6 &&
1376 !V_interface_timers_running6 &&
1377 !V_state_change_timers_running6)
1378 return;
1379
1380 IN6_MULTI_LIST_LOCK();
1381 MLD_LOCK();
1382
1383 /*
1384 * MLDv2 General Query response timer processing.
1385 */
1386 if (V_interface_timers_running6) {
1387 CTR1(KTR_MLD, "%s: interface timers running", __func__);
1388
1389 V_interface_timers_running6 = 0;
1390 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1391 if (mli->mli_v2_timer == 0) {
1392 /* Do nothing. */
1393 } else if (--mli->mli_v2_timer == 0) {
1394 mld_v2_dispatch_general_query(mli);
1395 } else {
1396 V_interface_timers_running6 = 1;
1397 }
1398 }
1399 }
1400
1401 if (!V_current_state_timers_running6 &&
1402 !V_state_change_timers_running6)
1403 goto out_locked;
1404
1405 V_current_state_timers_running6 = 0;
1406 V_state_change_timers_running6 = 0;
1407
1408 CTR1(KTR_MLD, "%s: state change timers running", __func__);
1409
1410 /*
1411 * MLD host report and state-change timer processing.
1412 * Note: Processing a v2 group timer may remove a node.
1413 */
1414 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1415 ifp = mli->mli_ifp;
1416
1417 if (mli->mli_version == MLD_VERSION_2) {
1418 uri_fasthz = MLD_RANDOM_DELAY(mli->mli_uri *
1419 PR_FASTHZ);
1420 mbufq_init(&qrq, MLD_MAX_G_GS_PACKETS);
1421 mbufq_init(&scq, MLD_MAX_STATE_CHANGE_PACKETS);
1422 }
1423
1424 IF_ADDR_WLOCK(ifp);
1425 NET_EPOCH_ENTER_ET(et);
1426 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1427 inm = in6m_ifmultiaddr_get_inm(ifma);
1428 if (inm == NULL)
1429 continue;
1430 switch (mli->mli_version) {
1431 case MLD_VERSION_1:
1432 mld_v1_process_group_timer(inmh, inm);
1433 break;
1434 case MLD_VERSION_2:
1435 mld_v2_process_group_timers(inmh, &qrq,
1436 &scq, inm, uri_fasthz);
1437 break;
1438 }
1439 }
1440 IF_ADDR_WUNLOCK(ifp);
1441
1442 switch (mli->mli_version) {
1443 case MLD_VERSION_1:
1444 /*
1445 * Transmit reports for this lifecycle. This
1446 * is done while not holding IF_ADDR_LOCK
1447 * since this can call
1448 * in6ifa_ifpforlinklocal() which locks
1449 * IF_ADDR_LOCK internally as well as
1450 * ip6_output() to transmit a packet.
1451 */
1452 while ((inm = SLIST_FIRST(inmh)) != NULL) {
1453 SLIST_REMOVE_HEAD(inmh, in6m_defer);
1454 (void)mld_v1_transmit_report(inm,
1455 MLD_LISTENER_REPORT);
1456 }
1457 break;
1458 case MLD_VERSION_2:
1459 mld_dispatch_queue(&qrq, 0);
1460 mld_dispatch_queue(&scq, 0);
1461 break;
1462 }
1463 NET_EPOCH_EXIT_ET(et);
1464 }
1465
1466 out_locked:
1467 MLD_UNLOCK();
1468 IN6_MULTI_LIST_UNLOCK();
1469 }
1470
1471 /*
1472 * Update host report group timer.
1473 * Will update the global pending timer flags.
1474 */
1475 static void
mld_v1_process_group_timer(struct in6_multi_head * inmh,struct in6_multi * inm)1476 mld_v1_process_group_timer(struct in6_multi_head *inmh, struct in6_multi *inm)
1477 {
1478 int report_timer_expired;
1479
1480 IN6_MULTI_LIST_LOCK_ASSERT();
1481 MLD_LOCK_ASSERT();
1482
1483 if (inm->in6m_timer == 0) {
1484 report_timer_expired = 0;
1485 } else if (--inm->in6m_timer == 0) {
1486 report_timer_expired = 1;
1487 } else {
1488 V_current_state_timers_running6 = 1;
1489 return;
1490 }
1491
1492 switch (inm->in6m_state) {
1493 case MLD_NOT_MEMBER:
1494 case MLD_SILENT_MEMBER:
1495 case MLD_IDLE_MEMBER:
1496 case MLD_LAZY_MEMBER:
1497 case MLD_SLEEPING_MEMBER:
1498 case MLD_AWAKENING_MEMBER:
1499 break;
1500 case MLD_REPORTING_MEMBER:
1501 if (report_timer_expired) {
1502 inm->in6m_state = MLD_IDLE_MEMBER;
1503 SLIST_INSERT_HEAD(inmh, inm, in6m_defer);
1504 }
1505 break;
1506 case MLD_G_QUERY_PENDING_MEMBER:
1507 case MLD_SG_QUERY_PENDING_MEMBER:
1508 case MLD_LEAVING_MEMBER:
1509 break;
1510 }
1511 }
1512
1513 /*
1514 * Update a group's timers for MLDv2.
1515 * Will update the global pending timer flags.
1516 * Note: Unlocked read from mli.
1517 */
1518 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)1519 mld_v2_process_group_timers(struct in6_multi_head *inmh,
1520 struct mbufq *qrq, struct mbufq *scq,
1521 struct in6_multi *inm, const int uri_fasthz)
1522 {
1523 int query_response_timer_expired;
1524 int state_change_retransmit_timer_expired;
1525 #ifdef KTR
1526 char ip6tbuf[INET6_ADDRSTRLEN];
1527 #endif
1528
1529 IN6_MULTI_LIST_LOCK_ASSERT();
1530 MLD_LOCK_ASSERT();
1531
1532 query_response_timer_expired = 0;
1533 state_change_retransmit_timer_expired = 0;
1534
1535 /*
1536 * During a transition from compatibility mode back to MLDv2,
1537 * a group record in REPORTING state may still have its group
1538 * timer active. This is a no-op in this function; it is easier
1539 * to deal with it here than to complicate the slow-timeout path.
1540 */
1541 if (inm->in6m_timer == 0) {
1542 query_response_timer_expired = 0;
1543 } else if (--inm->in6m_timer == 0) {
1544 query_response_timer_expired = 1;
1545 } else {
1546 V_current_state_timers_running6 = 1;
1547 }
1548
1549 if (inm->in6m_sctimer == 0) {
1550 state_change_retransmit_timer_expired = 0;
1551 } else if (--inm->in6m_sctimer == 0) {
1552 state_change_retransmit_timer_expired = 1;
1553 } else {
1554 V_state_change_timers_running6 = 1;
1555 }
1556
1557 /* We are in fasttimo, so be quick about it. */
1558 if (!state_change_retransmit_timer_expired &&
1559 !query_response_timer_expired)
1560 return;
1561
1562 switch (inm->in6m_state) {
1563 case MLD_NOT_MEMBER:
1564 case MLD_SILENT_MEMBER:
1565 case MLD_SLEEPING_MEMBER:
1566 case MLD_LAZY_MEMBER:
1567 case MLD_AWAKENING_MEMBER:
1568 case MLD_IDLE_MEMBER:
1569 break;
1570 case MLD_G_QUERY_PENDING_MEMBER:
1571 case MLD_SG_QUERY_PENDING_MEMBER:
1572 /*
1573 * Respond to a previously pending Group-Specific
1574 * or Group-and-Source-Specific query by enqueueing
1575 * the appropriate Current-State report for
1576 * immediate transmission.
1577 */
1578 if (query_response_timer_expired) {
1579 int retval;
1580
1581 retval = mld_v2_enqueue_group_record(qrq, inm, 0, 1,
1582 (inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER),
1583 0);
1584 CTR2(KTR_MLD, "%s: enqueue record = %d",
1585 __func__, retval);
1586 inm->in6m_state = MLD_REPORTING_MEMBER;
1587 in6m_clear_recorded(inm);
1588 }
1589 /* FALLTHROUGH */
1590 case MLD_REPORTING_MEMBER:
1591 case MLD_LEAVING_MEMBER:
1592 if (state_change_retransmit_timer_expired) {
1593 /*
1594 * State-change retransmission timer fired.
1595 * If there are any further pending retransmissions,
1596 * set the global pending state-change flag, and
1597 * reset the timer.
1598 */
1599 if (--inm->in6m_scrv > 0) {
1600 inm->in6m_sctimer = uri_fasthz;
1601 V_state_change_timers_running6 = 1;
1602 }
1603 /*
1604 * Retransmit the previously computed state-change
1605 * report. If there are no further pending
1606 * retransmissions, the mbuf queue will be consumed.
1607 * Update T0 state to T1 as we have now sent
1608 * a state-change.
1609 */
1610 (void)mld_v2_merge_state_changes(inm, scq);
1611
1612 in6m_commit(inm);
1613 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
1614 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1615 if_name(inm->in6m_ifp));
1616
1617 /*
1618 * If we are leaving the group for good, make sure
1619 * we release MLD's reference to it.
1620 * This release must be deferred using a SLIST,
1621 * as we are called from a loop which traverses
1622 * the in_ifmultiaddr TAILQ.
1623 */
1624 if (inm->in6m_state == MLD_LEAVING_MEMBER &&
1625 inm->in6m_scrv == 0) {
1626 inm->in6m_state = MLD_NOT_MEMBER;
1627 in6m_disconnect_locked(inmh, inm);
1628 in6m_rele_locked(inmh, inm);
1629 }
1630 }
1631 break;
1632 }
1633 }
1634
1635 /*
1636 * Switch to a different version on the given interface,
1637 * as per Section 9.12.
1638 */
1639 static void
mld_set_version(struct mld_ifsoftc * mli,const int version)1640 mld_set_version(struct mld_ifsoftc *mli, const int version)
1641 {
1642 int old_version_timer;
1643
1644 MLD_LOCK_ASSERT();
1645
1646 CTR4(KTR_MLD, "%s: switching to v%d on ifp %p(%s)", __func__,
1647 version, mli->mli_ifp, if_name(mli->mli_ifp));
1648
1649 if (version == MLD_VERSION_1) {
1650 /*
1651 * Compute the "Older Version Querier Present" timer as per
1652 * Section 9.12.
1653 */
1654 old_version_timer = (mli->mli_rv * mli->mli_qi) + mli->mli_qri;
1655 old_version_timer *= PR_SLOWHZ;
1656 mli->mli_v1_timer = old_version_timer;
1657 }
1658
1659 if (mli->mli_v1_timer > 0 && mli->mli_version != MLD_VERSION_1) {
1660 mli->mli_version = MLD_VERSION_1;
1661 mld_v2_cancel_link_timers(mli);
1662 }
1663 }
1664
1665 /*
1666 * Cancel pending MLDv2 timers for the given link and all groups
1667 * joined on it; state-change, general-query, and group-query timers.
1668 */
1669 static void
mld_v2_cancel_link_timers(struct mld_ifsoftc * mli)1670 mld_v2_cancel_link_timers(struct mld_ifsoftc *mli)
1671 {
1672 struct epoch_tracker et;
1673 struct in6_multi_head inmh;
1674 struct ifmultiaddr *ifma;
1675 struct ifnet *ifp;
1676 struct in6_multi *inm;
1677
1678 CTR3(KTR_MLD, "%s: cancel v2 timers on ifp %p(%s)", __func__,
1679 mli->mli_ifp, if_name(mli->mli_ifp));
1680
1681 SLIST_INIT(&inmh);
1682 IN6_MULTI_LIST_LOCK_ASSERT();
1683 MLD_LOCK_ASSERT();
1684
1685 /*
1686 * Fast-track this potentially expensive operation
1687 * by checking all the global 'timer pending' flags.
1688 */
1689 if (!V_interface_timers_running6 &&
1690 !V_state_change_timers_running6 &&
1691 !V_current_state_timers_running6)
1692 return;
1693
1694 mli->mli_v2_timer = 0;
1695
1696 ifp = mli->mli_ifp;
1697
1698 IF_ADDR_WLOCK(ifp);
1699 NET_EPOCH_ENTER_ET(et);
1700 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1701 inm = in6m_ifmultiaddr_get_inm(ifma);
1702 if (inm == NULL)
1703 continue;
1704 switch (inm->in6m_state) {
1705 case MLD_NOT_MEMBER:
1706 case MLD_SILENT_MEMBER:
1707 case MLD_IDLE_MEMBER:
1708 case MLD_LAZY_MEMBER:
1709 case MLD_SLEEPING_MEMBER:
1710 case MLD_AWAKENING_MEMBER:
1711 break;
1712 case MLD_LEAVING_MEMBER:
1713 /*
1714 * If we are leaving the group and switching
1715 * version, we need to release the final
1716 * reference held for issuing the INCLUDE {}.
1717 */
1718 if (inm->in6m_refcount == 1)
1719 in6m_disconnect_locked(&inmh, inm);
1720 in6m_rele_locked(&inmh, inm);
1721 /* FALLTHROUGH */
1722 case MLD_G_QUERY_PENDING_MEMBER:
1723 case MLD_SG_QUERY_PENDING_MEMBER:
1724 in6m_clear_recorded(inm);
1725 /* FALLTHROUGH */
1726 case MLD_REPORTING_MEMBER:
1727 inm->in6m_sctimer = 0;
1728 inm->in6m_timer = 0;
1729 inm->in6m_state = MLD_REPORTING_MEMBER;
1730 /*
1731 * Free any pending MLDv2 state-change records.
1732 */
1733 mbufq_drain(&inm->in6m_scq);
1734 break;
1735 }
1736 }
1737 NET_EPOCH_EXIT_ET(et);
1738 IF_ADDR_WUNLOCK(ifp);
1739 in6m_release_list_deferred(&inmh);
1740 }
1741
1742 /*
1743 * Global slowtimo handler.
1744 * VIMAGE: Timeout handlers are expected to service all vimages.
1745 */
1746 void
mld_slowtimo(void)1747 mld_slowtimo(void)
1748 {
1749 VNET_ITERATOR_DECL(vnet_iter);
1750
1751 VNET_LIST_RLOCK_NOSLEEP();
1752 VNET_FOREACH(vnet_iter) {
1753 CURVNET_SET(vnet_iter);
1754 mld_slowtimo_vnet();
1755 CURVNET_RESTORE();
1756 }
1757 VNET_LIST_RUNLOCK_NOSLEEP();
1758 }
1759
1760 /*
1761 * Per-vnet slowtimo handler.
1762 */
1763 static void
mld_slowtimo_vnet(void)1764 mld_slowtimo_vnet(void)
1765 {
1766 struct mld_ifsoftc *mli;
1767
1768 MLD_LOCK();
1769
1770 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1771 mld_v1_process_querier_timers(mli);
1772 }
1773
1774 MLD_UNLOCK();
1775 }
1776
1777 /*
1778 * Update the Older Version Querier Present timers for a link.
1779 * See Section 9.12 of RFC 3810.
1780 */
1781 static void
mld_v1_process_querier_timers(struct mld_ifsoftc * mli)1782 mld_v1_process_querier_timers(struct mld_ifsoftc *mli)
1783 {
1784
1785 MLD_LOCK_ASSERT();
1786
1787 if (mli->mli_version != MLD_VERSION_2 && --mli->mli_v1_timer == 0) {
1788 /*
1789 * MLDv1 Querier Present timer expired; revert to MLDv2.
1790 */
1791 CTR5(KTR_MLD,
1792 "%s: transition from v%d -> v%d on %p(%s)",
1793 __func__, mli->mli_version, MLD_VERSION_2,
1794 mli->mli_ifp, if_name(mli->mli_ifp));
1795 mli->mli_version = MLD_VERSION_2;
1796 }
1797 }
1798
1799 /*
1800 * Transmit an MLDv1 report immediately.
1801 */
1802 static int
mld_v1_transmit_report(struct in6_multi * in6m,const int type)1803 mld_v1_transmit_report(struct in6_multi *in6m, const int type)
1804 {
1805 struct ifnet *ifp;
1806 struct in6_ifaddr *ia;
1807 struct ip6_hdr *ip6;
1808 struct mbuf *mh, *md;
1809 struct mld_hdr *mld;
1810
1811 IN6_MULTI_LIST_LOCK_ASSERT();
1812 MLD_LOCK_ASSERT();
1813
1814 ifp = in6m->in6m_ifp;
1815 /* in process of being freed */
1816 if (ifp == NULL)
1817 return (0);
1818 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1819 /* ia may be NULL if link-local address is tentative. */
1820
1821 mh = m_gethdr(M_NOWAIT, MT_DATA);
1822 if (mh == NULL) {
1823 if (ia != NULL)
1824 ifa_free(&ia->ia_ifa);
1825 return (ENOMEM);
1826 }
1827 md = m_get(M_NOWAIT, MT_DATA);
1828 if (md == NULL) {
1829 m_free(mh);
1830 if (ia != NULL)
1831 ifa_free(&ia->ia_ifa);
1832 return (ENOMEM);
1833 }
1834 mh->m_next = md;
1835
1836 /*
1837 * FUTURE: Consider increasing alignment by ETHER_HDR_LEN, so
1838 * that ether_output() does not need to allocate another mbuf
1839 * for the header in the most common case.
1840 */
1841 M_ALIGN(mh, sizeof(struct ip6_hdr));
1842 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
1843 mh->m_len = sizeof(struct ip6_hdr);
1844
1845 ip6 = mtod(mh, struct ip6_hdr *);
1846 ip6->ip6_flow = 0;
1847 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1848 ip6->ip6_vfc |= IPV6_VERSION;
1849 ip6->ip6_nxt = IPPROTO_ICMPV6;
1850 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
1851 ip6->ip6_dst = in6m->in6m_addr;
1852
1853 md->m_len = sizeof(struct mld_hdr);
1854 mld = mtod(md, struct mld_hdr *);
1855 mld->mld_type = type;
1856 mld->mld_code = 0;
1857 mld->mld_cksum = 0;
1858 mld->mld_maxdelay = 0;
1859 mld->mld_reserved = 0;
1860 mld->mld_addr = in6m->in6m_addr;
1861 in6_clearscope(&mld->mld_addr);
1862 mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
1863 sizeof(struct ip6_hdr), sizeof(struct mld_hdr));
1864
1865 mld_save_context(mh, ifp);
1866 mh->m_flags |= M_MLDV1;
1867
1868 mld_dispatch_packet(mh);
1869
1870 if (ia != NULL)
1871 ifa_free(&ia->ia_ifa);
1872 return (0);
1873 }
1874
1875 /*
1876 * Process a state change from the upper layer for the given IPv6 group.
1877 *
1878 * Each socket holds a reference on the in_multi in its own ip_moptions.
1879 * The socket layer will have made the necessary updates to.the group
1880 * state, it is now up to MLD to issue a state change report if there
1881 * has been any change between T0 (when the last state-change was issued)
1882 * and T1 (now).
1883 *
1884 * We use the MLDv2 state machine at group level. The MLd module
1885 * however makes the decision as to which MLD protocol version to speak.
1886 * A state change *from* INCLUDE {} always means an initial join.
1887 * A state change *to* INCLUDE {} always means a final leave.
1888 *
1889 * If delay is non-zero, and the state change is an initial multicast
1890 * join, the state change report will be delayed by 'delay' ticks
1891 * in units of PR_FASTHZ if MLDv1 is active on the link; otherwise
1892 * the initial MLDv2 state change report will be delayed by whichever
1893 * is sooner, a pending state-change timer or delay itself.
1894 *
1895 * VIMAGE: curvnet should have been set by caller, as this routine
1896 * is called from the socket option handlers.
1897 */
1898 int
mld_change_state(struct in6_multi * inm,const int delay)1899 mld_change_state(struct in6_multi *inm, const int delay)
1900 {
1901 struct mld_ifsoftc *mli;
1902 struct ifnet *ifp;
1903 int error;
1904
1905 IN6_MULTI_LIST_LOCK_ASSERT();
1906
1907 error = 0;
1908
1909 /*
1910 * Check if the in6_multi has already been disconnected.
1911 */
1912 if (inm->in6m_ifp == NULL) {
1913 CTR1(KTR_MLD, "%s: inm is disconnected", __func__);
1914 return (0);
1915 }
1916
1917 /*
1918 * Try to detect if the upper layer just asked us to change state
1919 * for an interface which has now gone away.
1920 */
1921 KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
1922 ifp = inm->in6m_ifma->ifma_ifp;
1923 if (ifp == NULL)
1924 return (0);
1925 /*
1926 * Sanity check that netinet6's notion of ifp is the
1927 * same as net's.
1928 */
1929 KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
1930
1931 MLD_LOCK();
1932 mli = MLD_IFINFO(ifp);
1933 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
1934
1935 /*
1936 * If we detect a state transition to or from MCAST_UNDEFINED
1937 * for this group, then we are starting or finishing an MLD
1938 * life cycle for this group.
1939 */
1940 if (inm->in6m_st[1].iss_fmode != inm->in6m_st[0].iss_fmode) {
1941 CTR3(KTR_MLD, "%s: inm transition %d -> %d", __func__,
1942 inm->in6m_st[0].iss_fmode, inm->in6m_st[1].iss_fmode);
1943 if (inm->in6m_st[0].iss_fmode == MCAST_UNDEFINED) {
1944 CTR1(KTR_MLD, "%s: initial join", __func__);
1945 error = mld_initial_join(inm, mli, delay);
1946 goto out_locked;
1947 } else if (inm->in6m_st[1].iss_fmode == MCAST_UNDEFINED) {
1948 CTR1(KTR_MLD, "%s: final leave", __func__);
1949 mld_final_leave(inm, mli);
1950 goto out_locked;
1951 }
1952 } else {
1953 CTR1(KTR_MLD, "%s: filter set change", __func__);
1954 }
1955
1956 error = mld_handle_state_change(inm, mli);
1957
1958 out_locked:
1959 MLD_UNLOCK();
1960 return (error);
1961 }
1962
1963 /*
1964 * Perform the initial join for an MLD group.
1965 *
1966 * When joining a group:
1967 * If the group should have its MLD traffic suppressed, do nothing.
1968 * MLDv1 starts sending MLDv1 host membership reports.
1969 * MLDv2 will schedule an MLDv2 state-change report containing the
1970 * initial state of the membership.
1971 *
1972 * If the delay argument is non-zero, then we must delay sending the
1973 * initial state change for delay ticks (in units of PR_FASTHZ).
1974 */
1975 static int
mld_initial_join(struct in6_multi * inm,struct mld_ifsoftc * mli,const int delay)1976 mld_initial_join(struct in6_multi *inm, struct mld_ifsoftc *mli,
1977 const int delay)
1978 {
1979 struct ifnet *ifp;
1980 struct mbufq *mq;
1981 int error, retval, syncstates;
1982 int odelay;
1983 #ifdef KTR
1984 char ip6tbuf[INET6_ADDRSTRLEN];
1985 #endif
1986
1987 CTR4(KTR_MLD, "%s: initial join %s on ifp %p(%s)",
1988 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1989 inm->in6m_ifp, if_name(inm->in6m_ifp));
1990
1991 error = 0;
1992 syncstates = 1;
1993
1994 ifp = inm->in6m_ifp;
1995
1996 IN6_MULTI_LIST_LOCK_ASSERT();
1997 MLD_LOCK_ASSERT();
1998
1999 KASSERT(mli && mli->mli_ifp == ifp, ("%s: inconsistent ifp", __func__));
2000
2001 /*
2002 * Groups joined on loopback or marked as 'not reported',
2003 * enter the MLD_SILENT_MEMBER state and
2004 * are never reported in any protocol exchanges.
2005 * All other groups enter the appropriate state machine
2006 * for the version in use on this link.
2007 * A link marked as MLIF_SILENT causes MLD to be completely
2008 * disabled for the link.
2009 */
2010 if ((ifp->if_flags & IFF_LOOPBACK) ||
2011 (mli->mli_flags & MLIF_SILENT) ||
2012 !mld_is_addr_reported(&inm->in6m_addr)) {
2013 CTR1(KTR_MLD,
2014 "%s: not kicking state machine for silent group", __func__);
2015 inm->in6m_state = MLD_SILENT_MEMBER;
2016 inm->in6m_timer = 0;
2017 } else {
2018 /*
2019 * Deal with overlapping in_multi lifecycle.
2020 * If this group was LEAVING, then make sure
2021 * we drop the reference we picked up to keep the
2022 * group around for the final INCLUDE {} enqueue.
2023 */
2024 if (mli->mli_version == MLD_VERSION_2 &&
2025 inm->in6m_state == MLD_LEAVING_MEMBER) {
2026 inm->in6m_refcount--;
2027 MPASS(inm->in6m_refcount > 0);
2028 }
2029 inm->in6m_state = MLD_REPORTING_MEMBER;
2030
2031 switch (mli->mli_version) {
2032 case MLD_VERSION_1:
2033 /*
2034 * If a delay was provided, only use it if
2035 * it is greater than the delay normally
2036 * used for an MLDv1 state change report,
2037 * and delay sending the initial MLDv1 report
2038 * by not transitioning to the IDLE state.
2039 */
2040 odelay = MLD_RANDOM_DELAY(MLD_V1_MAX_RI * PR_FASTHZ);
2041 if (delay) {
2042 inm->in6m_timer = max(delay, odelay);
2043 V_current_state_timers_running6 = 1;
2044 } else {
2045 inm->in6m_state = MLD_IDLE_MEMBER;
2046 error = mld_v1_transmit_report(inm,
2047 MLD_LISTENER_REPORT);
2048 if (error == 0) {
2049 inm->in6m_timer = odelay;
2050 V_current_state_timers_running6 = 1;
2051 }
2052 }
2053 break;
2054
2055 case MLD_VERSION_2:
2056 /*
2057 * Defer update of T0 to T1, until the first copy
2058 * of the state change has been transmitted.
2059 */
2060 syncstates = 0;
2061
2062 /*
2063 * Immediately enqueue a State-Change Report for
2064 * this interface, freeing any previous reports.
2065 * Don't kick the timers if there is nothing to do,
2066 * or if an error occurred.
2067 */
2068 mq = &inm->in6m_scq;
2069 mbufq_drain(mq);
2070 retval = mld_v2_enqueue_group_record(mq, inm, 1,
2071 0, 0, (mli->mli_flags & MLIF_USEALLOW));
2072 CTR2(KTR_MLD, "%s: enqueue record = %d",
2073 __func__, retval);
2074 if (retval <= 0) {
2075 error = retval * -1;
2076 break;
2077 }
2078
2079 /*
2080 * Schedule transmission of pending state-change
2081 * report up to RV times for this link. The timer
2082 * will fire at the next mld_fasttimo (~200ms),
2083 * giving us an opportunity to merge the reports.
2084 *
2085 * If a delay was provided to this function, only
2086 * use this delay if sooner than the existing one.
2087 */
2088 KASSERT(mli->mli_rv > 1,
2089 ("%s: invalid robustness %d", __func__,
2090 mli->mli_rv));
2091 inm->in6m_scrv = mli->mli_rv;
2092 if (delay) {
2093 if (inm->in6m_sctimer > 1) {
2094 inm->in6m_sctimer =
2095 min(inm->in6m_sctimer, delay);
2096 } else
2097 inm->in6m_sctimer = delay;
2098 } else
2099 inm->in6m_sctimer = 1;
2100 V_state_change_timers_running6 = 1;
2101
2102 error = 0;
2103 break;
2104 }
2105 }
2106
2107 /*
2108 * Only update the T0 state if state change is atomic,
2109 * i.e. we don't need to wait for a timer to fire before we
2110 * can consider the state change to have been communicated.
2111 */
2112 if (syncstates) {
2113 in6m_commit(inm);
2114 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2115 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2116 if_name(inm->in6m_ifp));
2117 }
2118
2119 return (error);
2120 }
2121
2122 /*
2123 * Issue an intermediate state change during the life-cycle.
2124 */
2125 static int
mld_handle_state_change(struct in6_multi * inm,struct mld_ifsoftc * mli)2126 mld_handle_state_change(struct in6_multi *inm, struct mld_ifsoftc *mli)
2127 {
2128 struct ifnet *ifp;
2129 int retval;
2130 #ifdef KTR
2131 char ip6tbuf[INET6_ADDRSTRLEN];
2132 #endif
2133
2134 CTR4(KTR_MLD, "%s: state change for %s on ifp %p(%s)",
2135 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2136 inm->in6m_ifp, if_name(inm->in6m_ifp));
2137
2138 ifp = inm->in6m_ifp;
2139
2140 IN6_MULTI_LIST_LOCK_ASSERT();
2141 MLD_LOCK_ASSERT();
2142
2143 KASSERT(mli && mli->mli_ifp == ifp,
2144 ("%s: inconsistent ifp", __func__));
2145
2146 if ((ifp->if_flags & IFF_LOOPBACK) ||
2147 (mli->mli_flags & MLIF_SILENT) ||
2148 !mld_is_addr_reported(&inm->in6m_addr) ||
2149 (mli->mli_version != MLD_VERSION_2)) {
2150 if (!mld_is_addr_reported(&inm->in6m_addr)) {
2151 CTR1(KTR_MLD,
2152 "%s: not kicking state machine for silent group", __func__);
2153 }
2154 CTR1(KTR_MLD, "%s: nothing to do", __func__);
2155 in6m_commit(inm);
2156 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2157 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2158 if_name(inm->in6m_ifp));
2159 return (0);
2160 }
2161
2162 mbufq_drain(&inm->in6m_scq);
2163
2164 retval = mld_v2_enqueue_group_record(&inm->in6m_scq, inm, 1, 0, 0,
2165 (mli->mli_flags & MLIF_USEALLOW));
2166 CTR2(KTR_MLD, "%s: enqueue record = %d", __func__, retval);
2167 if (retval <= 0)
2168 return (-retval);
2169
2170 /*
2171 * If record(s) were enqueued, start the state-change
2172 * report timer for this group.
2173 */
2174 inm->in6m_scrv = mli->mli_rv;
2175 inm->in6m_sctimer = 1;
2176 V_state_change_timers_running6 = 1;
2177
2178 return (0);
2179 }
2180
2181 /*
2182 * Perform the final leave for a multicast address.
2183 *
2184 * When leaving a group:
2185 * MLDv1 sends a DONE message, if and only if we are the reporter.
2186 * MLDv2 enqueues a state-change report containing a transition
2187 * to INCLUDE {} for immediate transmission.
2188 */
2189 static void
mld_final_leave(struct in6_multi * inm,struct mld_ifsoftc * mli)2190 mld_final_leave(struct in6_multi *inm, struct mld_ifsoftc *mli)
2191 {
2192 int syncstates;
2193 #ifdef KTR
2194 char ip6tbuf[INET6_ADDRSTRLEN];
2195 #endif
2196
2197 syncstates = 1;
2198
2199 CTR4(KTR_MLD, "%s: final leave %s on ifp %p(%s)",
2200 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2201 inm->in6m_ifp, if_name(inm->in6m_ifp));
2202
2203 IN6_MULTI_LIST_LOCK_ASSERT();
2204 MLD_LOCK_ASSERT();
2205
2206 switch (inm->in6m_state) {
2207 case MLD_NOT_MEMBER:
2208 case MLD_SILENT_MEMBER:
2209 case MLD_LEAVING_MEMBER:
2210 /* Already leaving or left; do nothing. */
2211 CTR1(KTR_MLD,
2212 "%s: not kicking state machine for silent group", __func__);
2213 break;
2214 case MLD_REPORTING_MEMBER:
2215 case MLD_IDLE_MEMBER:
2216 case MLD_G_QUERY_PENDING_MEMBER:
2217 case MLD_SG_QUERY_PENDING_MEMBER:
2218 if (mli->mli_version == MLD_VERSION_1) {
2219 #ifdef INVARIANTS
2220 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
2221 inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER)
2222 panic("%s: MLDv2 state reached, not MLDv2 mode",
2223 __func__);
2224 #endif
2225 mld_v1_transmit_report(inm, MLD_LISTENER_DONE);
2226 inm->in6m_state = MLD_NOT_MEMBER;
2227 V_current_state_timers_running6 = 1;
2228 } else if (mli->mli_version == MLD_VERSION_2) {
2229 /*
2230 * Stop group timer and all pending reports.
2231 * Immediately enqueue a state-change report
2232 * TO_IN {} to be sent on the next fast timeout,
2233 * giving us an opportunity to merge reports.
2234 */
2235 mbufq_drain(&inm->in6m_scq);
2236 inm->in6m_timer = 0;
2237 inm->in6m_scrv = mli->mli_rv;
2238 CTR4(KTR_MLD, "%s: Leaving %s/%s with %d "
2239 "pending retransmissions.", __func__,
2240 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2241 if_name(inm->in6m_ifp), inm->in6m_scrv);
2242 if (inm->in6m_scrv == 0) {
2243 inm->in6m_state = MLD_NOT_MEMBER;
2244 inm->in6m_sctimer = 0;
2245 } else {
2246 int retval;
2247
2248 in6m_acquire_locked(inm);
2249
2250 retval = mld_v2_enqueue_group_record(
2251 &inm->in6m_scq, inm, 1, 0, 0,
2252 (mli->mli_flags & MLIF_USEALLOW));
2253 KASSERT(retval != 0,
2254 ("%s: enqueue record = %d", __func__,
2255 retval));
2256
2257 inm->in6m_state = MLD_LEAVING_MEMBER;
2258 inm->in6m_sctimer = 1;
2259 V_state_change_timers_running6 = 1;
2260 syncstates = 0;
2261 }
2262 break;
2263 }
2264 break;
2265 case MLD_LAZY_MEMBER:
2266 case MLD_SLEEPING_MEMBER:
2267 case MLD_AWAKENING_MEMBER:
2268 /* Our reports are suppressed; do nothing. */
2269 break;
2270 }
2271
2272 if (syncstates) {
2273 in6m_commit(inm);
2274 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2275 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2276 if_name(inm->in6m_ifp));
2277 inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
2278 CTR3(KTR_MLD, "%s: T1 now MCAST_UNDEFINED for %p/%s",
2279 __func__, &inm->in6m_addr, if_name(inm->in6m_ifp));
2280 }
2281 }
2282
2283 /*
2284 * Enqueue an MLDv2 group record to the given output queue.
2285 *
2286 * If is_state_change is zero, a current-state record is appended.
2287 * If is_state_change is non-zero, a state-change report is appended.
2288 *
2289 * If is_group_query is non-zero, an mbuf packet chain is allocated.
2290 * If is_group_query is zero, and if there is a packet with free space
2291 * at the tail of the queue, it will be appended to providing there
2292 * is enough free space.
2293 * Otherwise a new mbuf packet chain is allocated.
2294 *
2295 * If is_source_query is non-zero, each source is checked to see if
2296 * it was recorded for a Group-Source query, and will be omitted if
2297 * it is not both in-mode and recorded.
2298 *
2299 * If use_block_allow is non-zero, state change reports for initial join
2300 * and final leave, on an inclusive mode group with a source list, will be
2301 * rewritten to use the ALLOW_NEW and BLOCK_OLD record types, respectively.
2302 *
2303 * The function will attempt to allocate leading space in the packet
2304 * for the IPv6+ICMP headers to be prepended without fragmenting the chain.
2305 *
2306 * If successful the size of all data appended to the queue is returned,
2307 * otherwise an error code less than zero is returned, or zero if
2308 * no record(s) were appended.
2309 */
2310 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)2311 mld_v2_enqueue_group_record(struct mbufq *mq, struct in6_multi *inm,
2312 const int is_state_change, const int is_group_query,
2313 const int is_source_query, const int use_block_allow)
2314 {
2315 struct mldv2_record mr;
2316 struct mldv2_record *pmr;
2317 struct ifnet *ifp;
2318 struct ip6_msource *ims, *nims;
2319 struct mbuf *m0, *m, *md;
2320 int is_filter_list_change;
2321 int minrec0len, m0srcs, msrcs, nbytes, off;
2322 int record_has_sources;
2323 int now;
2324 int type;
2325 uint8_t mode;
2326 #ifdef KTR
2327 char ip6tbuf[INET6_ADDRSTRLEN];
2328 #endif
2329
2330 IN6_MULTI_LIST_LOCK_ASSERT();
2331
2332 ifp = inm->in6m_ifp;
2333 is_filter_list_change = 0;
2334 m = NULL;
2335 m0 = NULL;
2336 m0srcs = 0;
2337 msrcs = 0;
2338 nbytes = 0;
2339 nims = NULL;
2340 record_has_sources = 1;
2341 pmr = NULL;
2342 type = MLD_DO_NOTHING;
2343 mode = inm->in6m_st[1].iss_fmode;
2344
2345 /*
2346 * If we did not transition out of ASM mode during t0->t1,
2347 * and there are no source nodes to process, we can skip
2348 * the generation of source records.
2349 */
2350 if (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0 &&
2351 inm->in6m_nsrc == 0)
2352 record_has_sources = 0;
2353
2354 if (is_state_change) {
2355 /*
2356 * Queue a state change record.
2357 * If the mode did not change, and there are non-ASM
2358 * listeners or source filters present,
2359 * we potentially need to issue two records for the group.
2360 * If there are ASM listeners, and there was no filter
2361 * mode transition of any kind, do nothing.
2362 *
2363 * If we are transitioning to MCAST_UNDEFINED, we need
2364 * not send any sources. A transition to/from this state is
2365 * considered inclusive with some special treatment.
2366 *
2367 * If we are rewriting initial joins/leaves to use
2368 * ALLOW/BLOCK, and the group's membership is inclusive,
2369 * we need to send sources in all cases.
2370 */
2371 if (mode != inm->in6m_st[0].iss_fmode) {
2372 if (mode == MCAST_EXCLUDE) {
2373 CTR1(KTR_MLD, "%s: change to EXCLUDE",
2374 __func__);
2375 type = MLD_CHANGE_TO_EXCLUDE_MODE;
2376 } else {
2377 CTR1(KTR_MLD, "%s: change to INCLUDE",
2378 __func__);
2379 if (use_block_allow) {
2380 /*
2381 * XXX
2382 * Here we're interested in state
2383 * edges either direction between
2384 * MCAST_UNDEFINED and MCAST_INCLUDE.
2385 * Perhaps we should just check
2386 * the group state, rather than
2387 * the filter mode.
2388 */
2389 if (mode == MCAST_UNDEFINED) {
2390 type = MLD_BLOCK_OLD_SOURCES;
2391 } else {
2392 type = MLD_ALLOW_NEW_SOURCES;
2393 }
2394 } else {
2395 type = MLD_CHANGE_TO_INCLUDE_MODE;
2396 if (mode == MCAST_UNDEFINED)
2397 record_has_sources = 0;
2398 }
2399 }
2400 } else {
2401 if (record_has_sources) {
2402 is_filter_list_change = 1;
2403 } else {
2404 type = MLD_DO_NOTHING;
2405 }
2406 }
2407 } else {
2408 /*
2409 * Queue a current state record.
2410 */
2411 if (mode == MCAST_EXCLUDE) {
2412 type = MLD_MODE_IS_EXCLUDE;
2413 } else if (mode == MCAST_INCLUDE) {
2414 type = MLD_MODE_IS_INCLUDE;
2415 KASSERT(inm->in6m_st[1].iss_asm == 0,
2416 ("%s: inm %p is INCLUDE but ASM count is %d",
2417 __func__, inm, inm->in6m_st[1].iss_asm));
2418 }
2419 }
2420
2421 /*
2422 * Generate the filter list changes using a separate function.
2423 */
2424 if (is_filter_list_change)
2425 return (mld_v2_enqueue_filter_change(mq, inm));
2426
2427 if (type == MLD_DO_NOTHING) {
2428 CTR3(KTR_MLD, "%s: nothing to do for %s/%s",
2429 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2430 if_name(inm->in6m_ifp));
2431 return (0);
2432 }
2433
2434 /*
2435 * If any sources are present, we must be able to fit at least
2436 * one in the trailing space of the tail packet's mbuf,
2437 * ideally more.
2438 */
2439 minrec0len = sizeof(struct mldv2_record);
2440 if (record_has_sources)
2441 minrec0len += sizeof(struct in6_addr);
2442
2443 CTR4(KTR_MLD, "%s: queueing %s for %s/%s", __func__,
2444 mld_rec_type_to_str(type),
2445 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2446 if_name(inm->in6m_ifp));
2447
2448 /*
2449 * Check if we have a packet in the tail of the queue for this
2450 * group into which the first group record for this group will fit.
2451 * Otherwise allocate a new packet.
2452 * Always allocate leading space for IP6+RA+ICMPV6+REPORT.
2453 * Note: Group records for G/GSR query responses MUST be sent
2454 * in their own packet.
2455 */
2456 m0 = mbufq_last(mq);
2457 if (!is_group_query &&
2458 m0 != NULL &&
2459 (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <= MLD_V2_REPORT_MAXRECS) &&
2460 (m0->m_pkthdr.len + minrec0len) <
2461 (ifp->if_mtu - MLD_MTUSPACE)) {
2462 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2463 sizeof(struct mldv2_record)) /
2464 sizeof(struct in6_addr);
2465 m = m0;
2466 CTR1(KTR_MLD, "%s: use existing packet", __func__);
2467 } else {
2468 if (mbufq_full(mq)) {
2469 CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2470 return (-ENOMEM);
2471 }
2472 m = NULL;
2473 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2474 sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2475 if (!is_state_change && !is_group_query)
2476 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2477 if (m == NULL)
2478 m = m_gethdr(M_NOWAIT, MT_DATA);
2479 if (m == NULL)
2480 return (-ENOMEM);
2481
2482 mld_save_context(m, ifp);
2483
2484 CTR1(KTR_MLD, "%s: allocated first packet", __func__);
2485 }
2486
2487 /*
2488 * Append group record.
2489 * If we have sources, we don't know how many yet.
2490 */
2491 mr.mr_type = type;
2492 mr.mr_datalen = 0;
2493 mr.mr_numsrc = 0;
2494 mr.mr_addr = inm->in6m_addr;
2495 in6_clearscope(&mr.mr_addr);
2496 if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2497 if (m != m0)
2498 m_freem(m);
2499 CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2500 return (-ENOMEM);
2501 }
2502 nbytes += sizeof(struct mldv2_record);
2503
2504 /*
2505 * Append as many sources as will fit in the first packet.
2506 * If we are appending to a new packet, the chain allocation
2507 * may potentially use clusters; use m_getptr() in this case.
2508 * If we are appending to an existing packet, we need to obtain
2509 * a pointer to the group record after m_append(), in case a new
2510 * mbuf was allocated.
2511 *
2512 * Only append sources which are in-mode at t1. If we are
2513 * transitioning to MCAST_UNDEFINED state on the group, and
2514 * use_block_allow is zero, do not include source entries.
2515 * Otherwise, we need to include this source in the report.
2516 *
2517 * Only report recorded sources in our filter set when responding
2518 * to a group-source query.
2519 */
2520 if (record_has_sources) {
2521 if (m == m0) {
2522 md = m_last(m);
2523 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2524 md->m_len - nbytes);
2525 } else {
2526 md = m_getptr(m, 0, &off);
2527 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2528 off);
2529 }
2530 msrcs = 0;
2531 RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs,
2532 nims) {
2533 CTR2(KTR_MLD, "%s: visit node %s", __func__,
2534 ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2535 now = im6s_get_mode(inm, ims, 1);
2536 CTR2(KTR_MLD, "%s: node is %d", __func__, now);
2537 if ((now != mode) ||
2538 (now == mode &&
2539 (!use_block_allow && mode == MCAST_UNDEFINED))) {
2540 CTR1(KTR_MLD, "%s: skip node", __func__);
2541 continue;
2542 }
2543 if (is_source_query && ims->im6s_stp == 0) {
2544 CTR1(KTR_MLD, "%s: skip unrecorded node",
2545 __func__);
2546 continue;
2547 }
2548 CTR1(KTR_MLD, "%s: append node", __func__);
2549 if (!m_append(m, sizeof(struct in6_addr),
2550 (void *)&ims->im6s_addr)) {
2551 if (m != m0)
2552 m_freem(m);
2553 CTR1(KTR_MLD, "%s: m_append() failed.",
2554 __func__);
2555 return (-ENOMEM);
2556 }
2557 nbytes += sizeof(struct in6_addr);
2558 ++msrcs;
2559 if (msrcs == m0srcs)
2560 break;
2561 }
2562 CTR2(KTR_MLD, "%s: msrcs is %d this packet", __func__,
2563 msrcs);
2564 pmr->mr_numsrc = htons(msrcs);
2565 nbytes += (msrcs * sizeof(struct in6_addr));
2566 }
2567
2568 if (is_source_query && msrcs == 0) {
2569 CTR1(KTR_MLD, "%s: no recorded sources to report", __func__);
2570 if (m != m0)
2571 m_freem(m);
2572 return (0);
2573 }
2574
2575 /*
2576 * We are good to go with first packet.
2577 */
2578 if (m != m0) {
2579 CTR1(KTR_MLD, "%s: enqueueing first packet", __func__);
2580 m->m_pkthdr.PH_vt.vt_nrecs = 1;
2581 mbufq_enqueue(mq, m);
2582 } else
2583 m->m_pkthdr.PH_vt.vt_nrecs++;
2584
2585 /*
2586 * No further work needed if no source list in packet(s).
2587 */
2588 if (!record_has_sources)
2589 return (nbytes);
2590
2591 /*
2592 * Whilst sources remain to be announced, we need to allocate
2593 * a new packet and fill out as many sources as will fit.
2594 * Always try for a cluster first.
2595 */
2596 while (nims != NULL) {
2597 if (mbufq_full(mq)) {
2598 CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2599 return (-ENOMEM);
2600 }
2601 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2602 if (m == NULL)
2603 m = m_gethdr(M_NOWAIT, MT_DATA);
2604 if (m == NULL)
2605 return (-ENOMEM);
2606 mld_save_context(m, ifp);
2607 md = m_getptr(m, 0, &off);
2608 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) + off);
2609 CTR1(KTR_MLD, "%s: allocated next packet", __func__);
2610
2611 if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2612 if (m != m0)
2613 m_freem(m);
2614 CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2615 return (-ENOMEM);
2616 }
2617 m->m_pkthdr.PH_vt.vt_nrecs = 1;
2618 nbytes += sizeof(struct mldv2_record);
2619
2620 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2621 sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2622
2623 msrcs = 0;
2624 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2625 CTR2(KTR_MLD, "%s: visit node %s",
2626 __func__, ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2627 now = im6s_get_mode(inm, ims, 1);
2628 if ((now != mode) ||
2629 (now == mode &&
2630 (!use_block_allow && mode == MCAST_UNDEFINED))) {
2631 CTR1(KTR_MLD, "%s: skip node", __func__);
2632 continue;
2633 }
2634 if (is_source_query && ims->im6s_stp == 0) {
2635 CTR1(KTR_MLD, "%s: skip unrecorded node",
2636 __func__);
2637 continue;
2638 }
2639 CTR1(KTR_MLD, "%s: append node", __func__);
2640 if (!m_append(m, sizeof(struct in6_addr),
2641 (void *)&ims->im6s_addr)) {
2642 if (m != m0)
2643 m_freem(m);
2644 CTR1(KTR_MLD, "%s: m_append() failed.",
2645 __func__);
2646 return (-ENOMEM);
2647 }
2648 ++msrcs;
2649 if (msrcs == m0srcs)
2650 break;
2651 }
2652 pmr->mr_numsrc = htons(msrcs);
2653 nbytes += (msrcs * sizeof(struct in6_addr));
2654
2655 CTR1(KTR_MLD, "%s: enqueueing next packet", __func__);
2656 mbufq_enqueue(mq, m);
2657 }
2658
2659 return (nbytes);
2660 }
2661
2662 /*
2663 * Type used to mark record pass completion.
2664 * We exploit the fact we can cast to this easily from the
2665 * current filter modes on each ip_msource node.
2666 */
2667 typedef enum {
2668 REC_NONE = 0x00, /* MCAST_UNDEFINED */
2669 REC_ALLOW = 0x01, /* MCAST_INCLUDE */
2670 REC_BLOCK = 0x02, /* MCAST_EXCLUDE */
2671 REC_FULL = REC_ALLOW | REC_BLOCK
2672 } rectype_t;
2673
2674 /*
2675 * Enqueue an MLDv2 filter list change to the given output queue.
2676 *
2677 * Source list filter state is held in an RB-tree. When the filter list
2678 * for a group is changed without changing its mode, we need to compute
2679 * the deltas between T0 and T1 for each source in the filter set,
2680 * and enqueue the appropriate ALLOW_NEW/BLOCK_OLD records.
2681 *
2682 * As we may potentially queue two record types, and the entire R-B tree
2683 * needs to be walked at once, we break this out into its own function
2684 * so we can generate a tightly packed queue of packets.
2685 *
2686 * XXX This could be written to only use one tree walk, although that makes
2687 * serializing into the mbuf chains a bit harder. For now we do two walks
2688 * which makes things easier on us, and it may or may not be harder on
2689 * the L2 cache.
2690 *
2691 * If successful the size of all data appended to the queue is returned,
2692 * otherwise an error code less than zero is returned, or zero if
2693 * no record(s) were appended.
2694 */
2695 static int
mld_v2_enqueue_filter_change(struct mbufq * mq,struct in6_multi * inm)2696 mld_v2_enqueue_filter_change(struct mbufq *mq, struct in6_multi *inm)
2697 {
2698 static const int MINRECLEN =
2699 sizeof(struct mldv2_record) + sizeof(struct in6_addr);
2700 struct ifnet *ifp;
2701 struct mldv2_record mr;
2702 struct mldv2_record *pmr;
2703 struct ip6_msource *ims, *nims;
2704 struct mbuf *m, *m0, *md;
2705 int m0srcs, nbytes, npbytes, off, rsrcs, schanged;
2706 int nallow, nblock;
2707 uint8_t mode, now, then;
2708 rectype_t crt, drt, nrt;
2709 #ifdef KTR
2710 char ip6tbuf[INET6_ADDRSTRLEN];
2711 #endif
2712
2713 IN6_MULTI_LIST_LOCK_ASSERT();
2714
2715 if (inm->in6m_nsrc == 0 ||
2716 (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0))
2717 return (0);
2718
2719 ifp = inm->in6m_ifp; /* interface */
2720 mode = inm->in6m_st[1].iss_fmode; /* filter mode at t1 */
2721 crt = REC_NONE; /* current group record type */
2722 drt = REC_NONE; /* mask of completed group record types */
2723 nrt = REC_NONE; /* record type for current node */
2724 m0srcs = 0; /* # source which will fit in current mbuf chain */
2725 npbytes = 0; /* # of bytes appended this packet */
2726 nbytes = 0; /* # of bytes appended to group's state-change queue */
2727 rsrcs = 0; /* # sources encoded in current record */
2728 schanged = 0; /* # nodes encoded in overall filter change */
2729 nallow = 0; /* # of source entries in ALLOW_NEW */
2730 nblock = 0; /* # of source entries in BLOCK_OLD */
2731 nims = NULL; /* next tree node pointer */
2732
2733 /*
2734 * For each possible filter record mode.
2735 * The first kind of source we encounter tells us which
2736 * is the first kind of record we start appending.
2737 * If a node transitioned to UNDEFINED at t1, its mode is treated
2738 * as the inverse of the group's filter mode.
2739 */
2740 while (drt != REC_FULL) {
2741 do {
2742 m0 = mbufq_last(mq);
2743 if (m0 != NULL &&
2744 (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <=
2745 MLD_V2_REPORT_MAXRECS) &&
2746 (m0->m_pkthdr.len + MINRECLEN) <
2747 (ifp->if_mtu - MLD_MTUSPACE)) {
2748 m = m0;
2749 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2750 sizeof(struct mldv2_record)) /
2751 sizeof(struct in6_addr);
2752 CTR1(KTR_MLD,
2753 "%s: use previous packet", __func__);
2754 } else {
2755 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2756 if (m == NULL)
2757 m = m_gethdr(M_NOWAIT, MT_DATA);
2758 if (m == NULL) {
2759 CTR1(KTR_MLD,
2760 "%s: m_get*() failed", __func__);
2761 return (-ENOMEM);
2762 }
2763 m->m_pkthdr.PH_vt.vt_nrecs = 0;
2764 mld_save_context(m, ifp);
2765 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2766 sizeof(struct mldv2_record)) /
2767 sizeof(struct in6_addr);
2768 npbytes = 0;
2769 CTR1(KTR_MLD,
2770 "%s: allocated new packet", __func__);
2771 }
2772 /*
2773 * Append the MLD group record header to the
2774 * current packet's data area.
2775 * Recalculate pointer to free space for next
2776 * group record, in case m_append() allocated
2777 * a new mbuf or cluster.
2778 */
2779 memset(&mr, 0, sizeof(mr));
2780 mr.mr_addr = inm->in6m_addr;
2781 in6_clearscope(&mr.mr_addr);
2782 if (!m_append(m, sizeof(mr), (void *)&mr)) {
2783 if (m != m0)
2784 m_freem(m);
2785 CTR1(KTR_MLD,
2786 "%s: m_append() failed", __func__);
2787 return (-ENOMEM);
2788 }
2789 npbytes += sizeof(struct mldv2_record);
2790 if (m != m0) {
2791 /* new packet; offset in chain */
2792 md = m_getptr(m, npbytes -
2793 sizeof(struct mldv2_record), &off);
2794 pmr = (struct mldv2_record *)(mtod(md,
2795 uint8_t *) + off);
2796 } else {
2797 /* current packet; offset from last append */
2798 md = m_last(m);
2799 pmr = (struct mldv2_record *)(mtod(md,
2800 uint8_t *) + md->m_len -
2801 sizeof(struct mldv2_record));
2802 }
2803 /*
2804 * Begin walking the tree for this record type
2805 * pass, or continue from where we left off
2806 * previously if we had to allocate a new packet.
2807 * Only report deltas in-mode at t1.
2808 * We need not report included sources as allowed
2809 * if we are in inclusive mode on the group,
2810 * however the converse is not true.
2811 */
2812 rsrcs = 0;
2813 if (nims == NULL) {
2814 nims = RB_MIN(ip6_msource_tree,
2815 &inm->in6m_srcs);
2816 }
2817 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2818 CTR2(KTR_MLD, "%s: visit node %s", __func__,
2819 ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2820 now = im6s_get_mode(inm, ims, 1);
2821 then = im6s_get_mode(inm, ims, 0);
2822 CTR3(KTR_MLD, "%s: mode: t0 %d, t1 %d",
2823 __func__, then, now);
2824 if (now == then) {
2825 CTR1(KTR_MLD,
2826 "%s: skip unchanged", __func__);
2827 continue;
2828 }
2829 if (mode == MCAST_EXCLUDE &&
2830 now == MCAST_INCLUDE) {
2831 CTR1(KTR_MLD,
2832 "%s: skip IN src on EX group",
2833 __func__);
2834 continue;
2835 }
2836 nrt = (rectype_t)now;
2837 if (nrt == REC_NONE)
2838 nrt = (rectype_t)(~mode & REC_FULL);
2839 if (schanged++ == 0) {
2840 crt = nrt;
2841 } else if (crt != nrt)
2842 continue;
2843 if (!m_append(m, sizeof(struct in6_addr),
2844 (void *)&ims->im6s_addr)) {
2845 if (m != m0)
2846 m_freem(m);
2847 CTR1(KTR_MLD,
2848 "%s: m_append() failed", __func__);
2849 return (-ENOMEM);
2850 }
2851 nallow += !!(crt == REC_ALLOW);
2852 nblock += !!(crt == REC_BLOCK);
2853 if (++rsrcs == m0srcs)
2854 break;
2855 }
2856 /*
2857 * If we did not append any tree nodes on this
2858 * pass, back out of allocations.
2859 */
2860 if (rsrcs == 0) {
2861 npbytes -= sizeof(struct mldv2_record);
2862 if (m != m0) {
2863 CTR1(KTR_MLD,
2864 "%s: m_free(m)", __func__);
2865 m_freem(m);
2866 } else {
2867 CTR1(KTR_MLD,
2868 "%s: m_adj(m, -mr)", __func__);
2869 m_adj(m, -((int)sizeof(
2870 struct mldv2_record)));
2871 }
2872 continue;
2873 }
2874 npbytes += (rsrcs * sizeof(struct in6_addr));
2875 if (crt == REC_ALLOW)
2876 pmr->mr_type = MLD_ALLOW_NEW_SOURCES;
2877 else if (crt == REC_BLOCK)
2878 pmr->mr_type = MLD_BLOCK_OLD_SOURCES;
2879 pmr->mr_numsrc = htons(rsrcs);
2880 /*
2881 * Count the new group record, and enqueue this
2882 * packet if it wasn't already queued.
2883 */
2884 m->m_pkthdr.PH_vt.vt_nrecs++;
2885 if (m != m0)
2886 mbufq_enqueue(mq, m);
2887 nbytes += npbytes;
2888 } while (nims != NULL);
2889 drt |= crt;
2890 crt = (~crt & REC_FULL);
2891 }
2892
2893 CTR3(KTR_MLD, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
2894 nallow, nblock);
2895
2896 return (nbytes);
2897 }
2898
2899 static int
mld_v2_merge_state_changes(struct in6_multi * inm,struct mbufq * scq)2900 mld_v2_merge_state_changes(struct in6_multi *inm, struct mbufq *scq)
2901 {
2902 struct mbufq *gq;
2903 struct mbuf *m; /* pending state-change */
2904 struct mbuf *m0; /* copy of pending state-change */
2905 struct mbuf *mt; /* last state-change in packet */
2906 int docopy, domerge;
2907 u_int recslen;
2908
2909 docopy = 0;
2910 domerge = 0;
2911 recslen = 0;
2912
2913 IN6_MULTI_LIST_LOCK_ASSERT();
2914 MLD_LOCK_ASSERT();
2915
2916 /*
2917 * If there are further pending retransmissions, make a writable
2918 * copy of each queued state-change message before merging.
2919 */
2920 if (inm->in6m_scrv > 0)
2921 docopy = 1;
2922
2923 gq = &inm->in6m_scq;
2924 #ifdef KTR
2925 if (mbufq_first(gq) == NULL) {
2926 CTR2(KTR_MLD, "%s: WARNING: queue for inm %p is empty",
2927 __func__, inm);
2928 }
2929 #endif
2930
2931 m = mbufq_first(gq);
2932 while (m != NULL) {
2933 /*
2934 * Only merge the report into the current packet if
2935 * there is sufficient space to do so; an MLDv2 report
2936 * packet may only contain 65,535 group records.
2937 * Always use a simple mbuf chain concatentation to do this,
2938 * as large state changes for single groups may have
2939 * allocated clusters.
2940 */
2941 domerge = 0;
2942 mt = mbufq_last(scq);
2943 if (mt != NULL) {
2944 recslen = m_length(m, NULL);
2945
2946 if ((mt->m_pkthdr.PH_vt.vt_nrecs +
2947 m->m_pkthdr.PH_vt.vt_nrecs <=
2948 MLD_V2_REPORT_MAXRECS) &&
2949 (mt->m_pkthdr.len + recslen <=
2950 (inm->in6m_ifp->if_mtu - MLD_MTUSPACE)))
2951 domerge = 1;
2952 }
2953
2954 if (!domerge && mbufq_full(gq)) {
2955 CTR2(KTR_MLD,
2956 "%s: outbound queue full, skipping whole packet %p",
2957 __func__, m);
2958 mt = m->m_nextpkt;
2959 if (!docopy)
2960 m_freem(m);
2961 m = mt;
2962 continue;
2963 }
2964
2965 if (!docopy) {
2966 CTR2(KTR_MLD, "%s: dequeueing %p", __func__, m);
2967 m0 = mbufq_dequeue(gq);
2968 m = m0->m_nextpkt;
2969 } else {
2970 CTR2(KTR_MLD, "%s: copying %p", __func__, m);
2971 m0 = m_dup(m, M_NOWAIT);
2972 if (m0 == NULL)
2973 return (ENOMEM);
2974 m0->m_nextpkt = NULL;
2975 m = m->m_nextpkt;
2976 }
2977
2978 if (!domerge) {
2979 CTR3(KTR_MLD, "%s: queueing %p to scq %p)",
2980 __func__, m0, scq);
2981 mbufq_enqueue(scq, m0);
2982 } else {
2983 struct mbuf *mtl; /* last mbuf of packet mt */
2984
2985 CTR3(KTR_MLD, "%s: merging %p with ifscq tail %p)",
2986 __func__, m0, mt);
2987
2988 mtl = m_last(mt);
2989 m0->m_flags &= ~M_PKTHDR;
2990 mt->m_pkthdr.len += recslen;
2991 mt->m_pkthdr.PH_vt.vt_nrecs +=
2992 m0->m_pkthdr.PH_vt.vt_nrecs;
2993
2994 mtl->m_next = m0;
2995 }
2996 }
2997
2998 return (0);
2999 }
3000
3001 /*
3002 * Respond to a pending MLDv2 General Query.
3003 */
3004 static void
mld_v2_dispatch_general_query(struct mld_ifsoftc * mli)3005 mld_v2_dispatch_general_query(struct mld_ifsoftc *mli)
3006 {
3007 struct ifmultiaddr *ifma;
3008 struct ifnet *ifp;
3009 struct in6_multi *inm;
3010 int retval;
3011
3012 IN6_MULTI_LIST_LOCK_ASSERT();
3013 MLD_LOCK_ASSERT();
3014
3015 KASSERT(mli->mli_version == MLD_VERSION_2,
3016 ("%s: called when version %d", __func__, mli->mli_version));
3017
3018 /*
3019 * Check that there are some packets queued. If so, send them first.
3020 * For large number of groups the reply to general query can take
3021 * many packets, we should finish sending them before starting of
3022 * queuing the new reply.
3023 */
3024 if (mbufq_len(&mli->mli_gq) != 0)
3025 goto send;
3026
3027 ifp = mli->mli_ifp;
3028
3029 IF_ADDR_RLOCK(ifp);
3030 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
3031 inm = in6m_ifmultiaddr_get_inm(ifma);
3032 if (inm == NULL)
3033 continue;
3034 KASSERT(ifp == inm->in6m_ifp,
3035 ("%s: inconsistent ifp", __func__));
3036
3037 switch (inm->in6m_state) {
3038 case MLD_NOT_MEMBER:
3039 case MLD_SILENT_MEMBER:
3040 break;
3041 case MLD_REPORTING_MEMBER:
3042 case MLD_IDLE_MEMBER:
3043 case MLD_LAZY_MEMBER:
3044 case MLD_SLEEPING_MEMBER:
3045 case MLD_AWAKENING_MEMBER:
3046 inm->in6m_state = MLD_REPORTING_MEMBER;
3047 retval = mld_v2_enqueue_group_record(&mli->mli_gq,
3048 inm, 0, 0, 0, 0);
3049 CTR2(KTR_MLD, "%s: enqueue record = %d",
3050 __func__, retval);
3051 break;
3052 case MLD_G_QUERY_PENDING_MEMBER:
3053 case MLD_SG_QUERY_PENDING_MEMBER:
3054 case MLD_LEAVING_MEMBER:
3055 break;
3056 }
3057 }
3058 IF_ADDR_RUNLOCK(ifp);
3059
3060 send:
3061 mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST);
3062
3063 /*
3064 * Slew transmission of bursts over 500ms intervals.
3065 */
3066 if (mbufq_first(&mli->mli_gq) != NULL) {
3067 mli->mli_v2_timer = 1 + MLD_RANDOM_DELAY(
3068 MLD_RESPONSE_BURST_INTERVAL);
3069 V_interface_timers_running6 = 1;
3070 }
3071 }
3072
3073 /*
3074 * Transmit the next pending message in the output queue.
3075 *
3076 * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
3077 * MRT: Nothing needs to be done, as MLD traffic is always local to
3078 * a link and uses a link-scope multicast address.
3079 */
3080 static void
mld_dispatch_packet(struct mbuf * m)3081 mld_dispatch_packet(struct mbuf *m)
3082 {
3083 struct ip6_moptions im6o;
3084 struct ifnet *ifp;
3085 struct ifnet *oifp;
3086 struct mbuf *m0;
3087 struct mbuf *md;
3088 struct ip6_hdr *ip6;
3089 struct mld_hdr *mld;
3090 int error;
3091 int off;
3092 int type;
3093 uint32_t ifindex;
3094
3095 CTR2(KTR_MLD, "%s: transmit %p", __func__, m);
3096
3097 /*
3098 * Set VNET image pointer from enqueued mbuf chain
3099 * before doing anything else. Whilst we use interface
3100 * indexes to guard against interface detach, they are
3101 * unique to each VIMAGE and must be retrieved.
3102 */
3103 ifindex = mld_restore_context(m);
3104
3105 /*
3106 * Check if the ifnet still exists. This limits the scope of
3107 * any race in the absence of a global ifp lock for low cost
3108 * (an array lookup).
3109 */
3110 ifp = ifnet_byindex(ifindex);
3111 if (ifp == NULL) {
3112 CTR3(KTR_MLD, "%s: dropped %p as ifindex %u went away.",
3113 __func__, m, ifindex);
3114 m_freem(m);
3115 IP6STAT_INC(ip6s_noroute);
3116 goto out;
3117 }
3118
3119 im6o.im6o_multicast_hlim = 1;
3120 im6o.im6o_multicast_loop = (V_ip6_mrouter != NULL);
3121 im6o.im6o_multicast_ifp = ifp;
3122
3123 if (m->m_flags & M_MLDV1) {
3124 m0 = m;
3125 } else {
3126 m0 = mld_v2_encap_report(ifp, m);
3127 if (m0 == NULL) {
3128 CTR2(KTR_MLD, "%s: dropped %p", __func__, m);
3129 IP6STAT_INC(ip6s_odropped);
3130 goto out;
3131 }
3132 }
3133
3134 mld_scrub_context(m0);
3135 m_clrprotoflags(m);
3136 m0->m_pkthdr.rcvif = V_loif;
3137
3138 ip6 = mtod(m0, struct ip6_hdr *);
3139 #if 0
3140 (void)in6_setscope(&ip6->ip6_dst, ifp, NULL); /* XXX LOR */
3141 #else
3142 /*
3143 * XXX XXX Break some KPI rules to prevent an LOR which would
3144 * occur if we called in6_setscope() at transmission.
3145 * See comments at top of file.
3146 */
3147 MLD_EMBEDSCOPE(&ip6->ip6_dst, ifp->if_index);
3148 #endif
3149
3150 /*
3151 * Retrieve the ICMPv6 type before handoff to ip6_output(),
3152 * so we can bump the stats.
3153 */
3154 md = m_getptr(m0, sizeof(struct ip6_hdr), &off);
3155 mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off);
3156 type = mld->mld_type;
3157
3158 oifp = NULL;
3159 error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o,
3160 &oifp, NULL);
3161 if (error) {
3162 CTR3(KTR_MLD, "%s: ip6_output(%p) = %d", __func__, m0, error);
3163 goto out;
3164 }
3165 ICMP6STAT_INC(icp6s_outhist[type]);
3166 if (oifp != NULL) {
3167 icmp6_ifstat_inc(oifp, ifs6_out_msg);
3168 switch (type) {
3169 case MLD_LISTENER_REPORT:
3170 case MLDV2_LISTENER_REPORT:
3171 icmp6_ifstat_inc(oifp, ifs6_out_mldreport);
3172 break;
3173 case MLD_LISTENER_DONE:
3174 icmp6_ifstat_inc(oifp, ifs6_out_mlddone);
3175 break;
3176 }
3177 }
3178 out:
3179 return;
3180 }
3181
3182 /*
3183 * Encapsulate an MLDv2 report.
3184 *
3185 * KAME IPv6 requires that hop-by-hop options be passed separately,
3186 * and that the IPv6 header be prepended in a separate mbuf.
3187 *
3188 * Returns a pointer to the new mbuf chain head, or NULL if the
3189 * allocation failed.
3190 */
3191 static struct mbuf *
mld_v2_encap_report(struct ifnet * ifp,struct mbuf * m)3192 mld_v2_encap_report(struct ifnet *ifp, struct mbuf *m)
3193 {
3194 struct mbuf *mh;
3195 struct mldv2_report *mld;
3196 struct ip6_hdr *ip6;
3197 struct in6_ifaddr *ia;
3198 int mldreclen;
3199
3200 KASSERT(ifp != NULL, ("%s: null ifp", __func__));
3201 KASSERT((m->m_flags & M_PKTHDR),
3202 ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
3203
3204 /*
3205 * RFC3590: OK to send as :: or tentative during DAD.
3206 */
3207 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
3208 if (ia == NULL)
3209 CTR1(KTR_MLD, "%s: warning: ia is NULL", __func__);
3210
3211 mh = m_gethdr(M_NOWAIT, MT_DATA);
3212 if (mh == NULL) {
3213 if (ia != NULL)
3214 ifa_free(&ia->ia_ifa);
3215 m_freem(m);
3216 return (NULL);
3217 }
3218 M_ALIGN(mh, sizeof(struct ip6_hdr) + sizeof(struct mldv2_report));
3219
3220 mldreclen = m_length(m, NULL);
3221 CTR2(KTR_MLD, "%s: mldreclen is %d", __func__, mldreclen);
3222
3223 mh->m_len = sizeof(struct ip6_hdr) + sizeof(struct mldv2_report);
3224 mh->m_pkthdr.len = sizeof(struct ip6_hdr) +
3225 sizeof(struct mldv2_report) + mldreclen;
3226
3227 ip6 = mtod(mh, struct ip6_hdr *);
3228 ip6->ip6_flow = 0;
3229 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
3230 ip6->ip6_vfc |= IPV6_VERSION;
3231 ip6->ip6_nxt = IPPROTO_ICMPV6;
3232 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
3233 if (ia != NULL)
3234 ifa_free(&ia->ia_ifa);
3235 ip6->ip6_dst = in6addr_linklocal_allv2routers;
3236 /* scope ID will be set in netisr */
3237
3238 mld = (struct mldv2_report *)(ip6 + 1);
3239 mld->mld_type = MLDV2_LISTENER_REPORT;
3240 mld->mld_code = 0;
3241 mld->mld_cksum = 0;
3242 mld->mld_v2_reserved = 0;
3243 mld->mld_v2_numrecs = htons(m->m_pkthdr.PH_vt.vt_nrecs);
3244 m->m_pkthdr.PH_vt.vt_nrecs = 0;
3245
3246 mh->m_next = m;
3247 mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
3248 sizeof(struct ip6_hdr), sizeof(struct mldv2_report) + mldreclen);
3249 return (mh);
3250 }
3251
3252 #ifdef KTR
3253 static char *
mld_rec_type_to_str(const int type)3254 mld_rec_type_to_str(const int type)
3255 {
3256
3257 switch (type) {
3258 case MLD_CHANGE_TO_EXCLUDE_MODE:
3259 return "TO_EX";
3260 break;
3261 case MLD_CHANGE_TO_INCLUDE_MODE:
3262 return "TO_IN";
3263 break;
3264 case MLD_MODE_IS_EXCLUDE:
3265 return "MODE_EX";
3266 break;
3267 case MLD_MODE_IS_INCLUDE:
3268 return "MODE_IN";
3269 break;
3270 case MLD_ALLOW_NEW_SOURCES:
3271 return "ALLOW_NEW";
3272 break;
3273 case MLD_BLOCK_OLD_SOURCES:
3274 return "BLOCK_OLD";
3275 break;
3276 default:
3277 break;
3278 }
3279 return "unknown";
3280 }
3281 #endif
3282
3283 static void
mld_init(void * unused __unused)3284 mld_init(void *unused __unused)
3285 {
3286
3287 CTR1(KTR_MLD, "%s: initializing", __func__);
3288 MLD_LOCK_INIT();
3289
3290 ip6_initpktopts(&mld_po);
3291 mld_po.ip6po_hlim = 1;
3292 mld_po.ip6po_hbh = &mld_ra.hbh;
3293 mld_po.ip6po_prefer_tempaddr = IP6PO_TEMPADDR_NOTPREFER;
3294 mld_po.ip6po_flags = IP6PO_DONTFRAG;
3295 }
3296 SYSINIT(mld_init, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_init, NULL);
3297
3298 static void
mld_uninit(void * unused __unused)3299 mld_uninit(void *unused __unused)
3300 {
3301
3302 CTR1(KTR_MLD, "%s: tearing down", __func__);
3303 MLD_LOCK_DESTROY();
3304 }
3305 SYSUNINIT(mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_uninit, NULL);
3306
3307 static void
vnet_mld_init(const void * unused __unused)3308 vnet_mld_init(const void *unused __unused)
3309 {
3310
3311 CTR1(KTR_MLD, "%s: initializing", __func__);
3312
3313 LIST_INIT(&V_mli_head);
3314 }
3315 VNET_SYSINIT(vnet_mld_init, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_init,
3316 NULL);
3317
3318 static void
vnet_mld_uninit(const void * unused __unused)3319 vnet_mld_uninit(const void *unused __unused)
3320 {
3321
3322 /* This can happen if we shutdown the network stack. */
3323 CTR1(KTR_MLD, "%s: tearing down", __func__);
3324 }
3325 VNET_SYSUNINIT(vnet_mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_uninit,
3326 NULL);
3327
3328 static int
mld_modevent(module_t mod,int type,void * unused __unused)3329 mld_modevent(module_t mod, int type, void *unused __unused)
3330 {
3331
3332 switch (type) {
3333 case MOD_LOAD:
3334 case MOD_UNLOAD:
3335 break;
3336 default:
3337 return (EOPNOTSUPP);
3338 }
3339 return (0);
3340 }
3341
3342 static moduledata_t mld_mod = {
3343 "mld",
3344 mld_modevent,
3345 0
3346 };
3347 DECLARE_MODULE(mld, mld_mod, SI_SUB_PROTO_MC, SI_ORDER_ANY);
3348