1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2009 Bruce Simpson.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $
31 */
32
33 /*-
34 * Copyright (c) 1988 Stephen Deering.
35 * Copyright (c) 1992, 1993
36 * The Regents of the University of California. All rights reserved.
37 *
38 * This code is derived from software contributed to Berkeley by
39 * Stephen Deering of Stanford University.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 * 3. Neither the name of the University nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 */
65
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/mbuf.h>
72 #include <sys/socket.h>
73 #include <sys/sysctl.h>
74 #include <sys/kernel.h>
75 #include <sys/callout.h>
76 #include <sys/malloc.h>
77 #include <sys/module.h>
78 #include <sys/ktr.h>
79
80 #include <net/if.h>
81 #include <net/if_var.h>
82 #include <net/if_private.h>
83 #include <net/route.h>
84 #include <net/vnet.h>
85
86 #include <netinet/in.h>
87 #include <netinet/in_var.h>
88 #include <netinet6/in6_var.h>
89 #include <netinet/ip6.h>
90 #include <netinet6/ip6_var.h>
91 #include <netinet6/scope6_var.h>
92 #include <netinet/icmp6.h>
93 #include <netinet6/mld6.h>
94 #include <netinet6/mld6_var.h>
95
96 #include <security/mac/mac_framework.h>
97
98 #ifndef KTR_MLD
99 #define KTR_MLD KTR_INET6
100 #endif
101
102 static void mld_dispatch_packet(struct mbuf *);
103 static void mld_dispatch_queue(struct mbufq *, int);
104 static void mld_final_leave(struct in6_multi *, struct mld_ifsoftc *);
105 static void mld_fasttimo_vnet(struct in6_multi_head *inmh);
106 static int mld_handle_state_change(struct in6_multi *,
107 struct mld_ifsoftc *);
108 static int mld_initial_join(struct in6_multi *, struct mld_ifsoftc *,
109 const int);
110 #ifdef KTR
111 static char * mld_rec_type_to_str(const int);
112 #endif
113 static void mld_set_version(struct mld_ifsoftc *, const int);
114 static void mld_slowtimo_vnet(void);
115 static int mld_v1_input_query(struct ifnet *, const struct ip6_hdr *,
116 /*const*/ struct mld_hdr *);
117 static int mld_v1_input_report(struct ifnet *, const struct ip6_hdr *,
118 /*const*/ struct mld_hdr *);
119 static void mld_v1_process_group_timer(struct in6_multi_head *,
120 struct in6_multi *);
121 static void mld_v1_process_querier_timers(struct mld_ifsoftc *);
122 static int mld_v1_transmit_report(struct in6_multi *, const int);
123 static void mld_v1_update_group(struct in6_multi *, const int);
124 static void mld_v2_cancel_link_timers(struct mld_ifsoftc *);
125 static void mld_v2_dispatch_general_query(struct mld_ifsoftc *);
126 static struct mbuf *
127 mld_v2_encap_report(struct ifnet *, struct mbuf *);
128 static int mld_v2_enqueue_filter_change(struct mbufq *,
129 struct in6_multi *);
130 static int mld_v2_enqueue_group_record(struct mbufq *,
131 struct in6_multi *, const int, const int, const int,
132 const int);
133 static int mld_v2_input_query(struct ifnet *, const struct ip6_hdr *,
134 struct mbuf *, struct mldv2_query *, const int, const int);
135 static int mld_v2_merge_state_changes(struct in6_multi *,
136 struct mbufq *);
137 static void mld_v2_process_group_timers(struct in6_multi_head *,
138 struct mbufq *, struct mbufq *,
139 struct in6_multi *, const int);
140 static int mld_v2_process_group_query(struct in6_multi *,
141 struct mld_ifsoftc *mli, int, struct mbuf *,
142 struct mldv2_query *, const int);
143 static int sysctl_mld_gsr(SYSCTL_HANDLER_ARGS);
144 static int sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS);
145
146 /*
147 * Normative references: RFC 2710, RFC 3590, RFC 3810.
148 *
149 * Locking:
150 * * The MLD subsystem lock ends up being system-wide for the moment,
151 * but could be per-VIMAGE later on.
152 * * The permitted lock order is: IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
153 * Any may be taken independently; if any are held at the same
154 * time, the above lock order must be followed.
155 * * IN6_MULTI_LOCK covers in_multi.
156 * * MLD_LOCK covers per-link state and any global variables in this file.
157 * * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
158 * per-link state iterators.
159 *
160 * XXX LOR PREVENTION
161 * A special case for IPv6 is the in6_setscope() routine. ip6_output()
162 * will not accept an ifp; it wants an embedded scope ID, unlike
163 * ip_output(), which happily takes the ifp given to it. The embedded
164 * scope ID is only used by MLD to select the outgoing interface.
165 *
166 * During interface attach and detach, MLD will take MLD_LOCK *after*
167 * the LLTABLE_LOCK.
168 * As in6_setscope() takes LLTABLE_LOCK then SCOPE_LOCK, we can't call
169 * it with MLD_LOCK held without triggering an LOR. A netisr with indirect
170 * dispatch could work around this, but we'd rather not do that, as it
171 * can introduce other races.
172 *
173 * As such, we exploit the fact that the scope ID is just the interface
174 * index, and embed it in the IPv6 destination address accordingly.
175 * This is potentially NOT VALID for MLDv1 reports, as they
176 * are always sent to the multicast group itself; as MLDv2
177 * reports are always sent to ff02::16, this is not an issue
178 * when MLDv2 is in use.
179 *
180 * This does not however eliminate the LOR when ip6_output() itself
181 * calls in6_setscope() internally whilst MLD_LOCK is held. This will
182 * trigger a LOR warning in WITNESS when the ifnet is detached.
183 *
184 * The right answer is probably to make LLTABLE_LOCK an rwlock, given
185 * how it's used across the network stack. Here we're simply exploiting
186 * the fact that MLD runs at a similar layer in the stack to scope6.c.
187 *
188 * VIMAGE:
189 * * Each in6_multi corresponds to an ifp, and each ifp corresponds
190 * to a vnet in ifp->if_vnet.
191 */
192 static struct mtx mld_mtx;
193 static MALLOC_DEFINE(M_MLD, "mld", "mld state");
194
195 #define MLD_EMBEDSCOPE(pin6, zoneid) \
196 if (IN6_IS_SCOPE_LINKLOCAL(pin6) || \
197 IN6_IS_ADDR_MC_INTFACELOCAL(pin6)) \
198 (pin6)->s6_addr16[1] = htons((zoneid) & 0xFFFF) \
199
200 /*
201 * VIMAGE-wide globals.
202 */
203 VNET_DEFINE_STATIC(struct timeval, mld_gsrdelay) = {10, 0};
204 VNET_DEFINE_STATIC(LIST_HEAD(, mld_ifsoftc), mli_head);
205 VNET_DEFINE_STATIC(int, interface_timers_running6);
206 VNET_DEFINE_STATIC(int, state_change_timers_running6);
207 VNET_DEFINE_STATIC(int, current_state_timers_running6);
208
209 #define V_mld_gsrdelay VNET(mld_gsrdelay)
210 #define V_mli_head VNET(mli_head)
211 #define V_interface_timers_running6 VNET(interface_timers_running6)
212 #define V_state_change_timers_running6 VNET(state_change_timers_running6)
213 #define V_current_state_timers_running6 VNET(current_state_timers_running6)
214
215 SYSCTL_DECL(_net_inet6); /* Note: Not in any common header. */
216
217 SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
218 "IPv6 Multicast Listener Discovery");
219
220 /*
221 * Virtualized sysctls.
222 */
223 SYSCTL_PROC(_net_inet6_mld, OID_AUTO, gsrdelay,
224 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
225 &VNET_NAME(mld_gsrdelay.tv_sec), 0, sysctl_mld_gsr, "I",
226 "Rate limit for MLDv2 Group-and-Source queries in seconds");
227
228 /*
229 * Non-virtualized sysctls.
230 */
231 static SYSCTL_NODE(_net_inet6_mld, OID_AUTO, ifinfo,
232 CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_mld_ifinfo,
233 "Per-interface MLDv2 state");
234
235 VNET_DEFINE_STATIC(bool, mld_v1enable) = true;
236 #define V_mld_v1enable VNET(mld_v1enable)
237 SYSCTL_BOOL(_net_inet6_mld, OID_AUTO, v1enable, CTLFLAG_VNET | CTLFLAG_RWTUN,
238 &VNET_NAME(mld_v1enable), 0, "Enable fallback to MLDv1");
239
240 VNET_DEFINE_STATIC(bool, mld_v2enable) = true;
241 #define V_mld_v2enable VNET(mld_v2enable)
242 SYSCTL_BOOL(_net_inet6_mld, OID_AUTO, v2enable, CTLFLAG_VNET | CTLFLAG_RWTUN,
243 &VNET_NAME(mld_v2enable), 0, "Enable MLDv2");
244
245 VNET_DEFINE_STATIC(bool, mld_use_allow) = true;
246 #define V_mld_use_allow VNET(mld_use_allow)
247 SYSCTL_BOOL(_net_inet6_mld, OID_AUTO, use_allow, CTLFLAG_VNET | CTLFLAG_RWTUN,
248 &VNET_NAME(mld_use_allow), 0, "Use ALLOW/BLOCK for RFC 4604 SSM joins/leaves");
249
250 /*
251 * Packed Router Alert option structure declaration.
252 */
253 struct mld_raopt {
254 struct ip6_hbh hbh;
255 struct ip6_opt pad;
256 struct ip6_opt_router ra;
257 } __packed;
258
259 /*
260 * Router Alert hop-by-hop option header.
261 */
262 static struct mld_raopt mld_ra = {
263 .hbh = { 0, 0 },
264 .pad = { .ip6o_type = IP6OPT_PADN, 0 },
265 .ra = {
266 .ip6or_type = IP6OPT_ROUTER_ALERT,
267 .ip6or_len = IP6OPT_RTALERT_LEN - 2,
268 .ip6or_value[0] = ((IP6OPT_RTALERT_MLD >> 8) & 0xFF),
269 .ip6or_value[1] = (IP6OPT_RTALERT_MLD & 0xFF)
270 }
271 };
272 static struct ip6_pktopts mld_po;
273
274 static __inline void
mld_save_context(struct mbuf * m,struct ifnet * ifp)275 mld_save_context(struct mbuf *m, struct ifnet *ifp)
276 {
277
278 #ifdef VIMAGE
279 m->m_pkthdr.PH_loc.ptr = ifp->if_vnet;
280 #endif /* VIMAGE */
281 m->m_pkthdr.rcvif = ifp;
282 m->m_pkthdr.flowid = ifp->if_index;
283 }
284
285 static __inline void
mld_scrub_context(struct mbuf * m)286 mld_scrub_context(struct mbuf *m)
287 {
288
289 m->m_pkthdr.PH_loc.ptr = NULL;
290 m->m_pkthdr.flowid = 0;
291 }
292
293 /*
294 * Restore context from a queued output chain.
295 * Return saved ifindex.
296 *
297 * VIMAGE: The assertion is there to make sure that we
298 * actually called CURVNET_SET() with what's in the mbuf chain.
299 */
300 static __inline uint32_t
mld_restore_context(struct mbuf * m)301 mld_restore_context(struct mbuf *m)
302 {
303
304 #if defined(VIMAGE) && defined(INVARIANTS)
305 KASSERT(curvnet == m->m_pkthdr.PH_loc.ptr,
306 ("%s: called when curvnet was not restored: cuvnet %p m ptr %p",
307 __func__, curvnet, m->m_pkthdr.PH_loc.ptr));
308 #endif
309 return (m->m_pkthdr.flowid);
310 }
311
312 /*
313 * Retrieve or set threshold between group-source queries in seconds.
314 *
315 * VIMAGE: Assume curvnet set by caller.
316 * SMPng: NOTE: Serialized by MLD lock.
317 */
318 static int
sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)319 sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
320 {
321 int error;
322 int i;
323
324 error = sysctl_wire_old_buffer(req, sizeof(int));
325 if (error)
326 return (error);
327
328 MLD_LOCK();
329
330 i = V_mld_gsrdelay.tv_sec;
331
332 error = sysctl_handle_int(oidp, &i, 0, req);
333 if (error || !req->newptr)
334 goto out_locked;
335
336 if (i < -1 || i >= 60) {
337 error = EINVAL;
338 goto out_locked;
339 }
340
341 CTR2(KTR_MLD, "change mld_gsrdelay from %d to %d",
342 V_mld_gsrdelay.tv_sec, i);
343 V_mld_gsrdelay.tv_sec = i;
344
345 out_locked:
346 MLD_UNLOCK();
347 return (error);
348 }
349
350 /*
351 * Expose struct mld_ifsoftc to userland, keyed by ifindex.
352 * For use by ifmcstat(8).
353 *
354 * VIMAGE: Assume curvnet set by caller. The node handler itself
355 * is not directly virtualized.
356 */
357 static int
sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)358 sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
359 {
360 struct epoch_tracker et;
361 int *name;
362 int error;
363 u_int namelen;
364 struct ifnet *ifp;
365 struct mld_ifsoftc *mli;
366
367 name = (int *)arg1;
368 namelen = arg2;
369
370 if (req->newptr != NULL)
371 return (EPERM);
372
373 if (namelen != 1)
374 return (EINVAL);
375
376 error = sysctl_wire_old_buffer(req, sizeof(struct mld_ifinfo));
377 if (error)
378 return (error);
379
380 IN6_MULTI_LOCK();
381 IN6_MULTI_LIST_LOCK();
382 MLD_LOCK();
383 NET_EPOCH_ENTER(et);
384
385 error = ENOENT;
386 ifp = ifnet_byindex(name[0]);
387 if (ifp == NULL)
388 goto out_locked;
389
390 LIST_FOREACH(mli, &V_mli_head, mli_link) {
391 if (ifp == mli->mli_ifp) {
392 struct mld_ifinfo info;
393
394 info.mli_version = mli->mli_version;
395 info.mli_v1_timer = mli->mli_v1_timer;
396 info.mli_v2_timer = mli->mli_v2_timer;
397 info.mli_flags = mli->mli_flags;
398 info.mli_rv = mli->mli_rv;
399 info.mli_qi = mli->mli_qi;
400 info.mli_qri = mli->mli_qri;
401 info.mli_uri = mli->mli_uri;
402 error = SYSCTL_OUT(req, &info, sizeof(info));
403 break;
404 }
405 }
406
407 out_locked:
408 NET_EPOCH_EXIT(et);
409 MLD_UNLOCK();
410 IN6_MULTI_LIST_UNLOCK();
411 IN6_MULTI_UNLOCK();
412 return (error);
413 }
414
415 /*
416 * Dispatch an entire queue of pending packet chains.
417 * VIMAGE: Assumes the vnet pointer has been set.
418 */
419 static void
mld_dispatch_queue(struct mbufq * mq,int limit)420 mld_dispatch_queue(struct mbufq *mq, int limit)
421 {
422 struct mbuf *m;
423
424 while ((m = mbufq_dequeue(mq)) != NULL) {
425 CTR3(KTR_MLD, "%s: dispatch %p from %p", __func__, mq, m);
426 mld_dispatch_packet(m);
427 if (--limit == 0)
428 break;
429 }
430 }
431
432 /*
433 * Filter outgoing MLD report state by group.
434 *
435 * Reports are ALWAYS suppressed for ALL-HOSTS (ff02::1)
436 * and node-local addresses. However, kernel and socket consumers
437 * always embed the KAME scope ID in the address provided, so strip it
438 * when performing comparison.
439 * Note: This is not the same as the *multicast* scope.
440 *
441 * Return zero if the given group is one for which MLD reports
442 * should be suppressed, or non-zero if reports should be issued.
443 */
444 static __inline int
mld_is_addr_reported(const struct in6_addr * addr)445 mld_is_addr_reported(const struct in6_addr *addr)
446 {
447
448 KASSERT(IN6_IS_ADDR_MULTICAST(addr), ("%s: not multicast", __func__));
449
450 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_NODELOCAL)
451 return (0);
452
453 if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_LINKLOCAL) {
454 struct in6_addr tmp = *addr;
455 in6_clearscope(&tmp);
456 if (IN6_ARE_ADDR_EQUAL(&tmp, &in6addr_linklocal_allnodes))
457 return (0);
458 }
459
460 return (1);
461 }
462
463 /*
464 * Attach MLD when PF_INET6 is attached to an interface. Assumes that the
465 * current VNET is set by the caller.
466 */
467 void
mld_domifattach(struct ifnet * ifp)468 mld_domifattach(struct ifnet *ifp)
469 {
470 struct mld_ifsoftc *mli = MLD_IFINFO(ifp);
471
472 CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp, if_name(ifp));
473
474 *mli = (struct mld_ifsoftc){
475 .mli_ifp = ifp,
476 .mli_version = MLD_VERSION_2,
477 .mli_rv = MLD_RV_INIT,
478 .mli_qi = MLD_QI_INIT,
479 .mli_qri = MLD_QRI_INIT,
480 .mli_uri = MLD_URI_INIT,
481 };
482 mbufq_init(&mli->mli_gq, MLD_MAX_RESPONSE_PACKETS);
483 if ((ifp->if_flags & IFF_MULTICAST) == 0)
484 mli->mli_flags |= MLIF_SILENT;
485 if (V_mld_use_allow)
486 mli->mli_flags |= MLIF_USEALLOW;
487
488 MLD_LOCK();
489 LIST_INSERT_HEAD(&V_mli_head, mli, mli_link);
490 MLD_UNLOCK();
491 }
492
493 /*
494 * Hook for ifdetach.
495 *
496 * NOTE: Some finalization tasks need to run before the protocol domain
497 * is detached, but also before the link layer does its cleanup.
498 * Run before link-layer cleanup; cleanup groups, but do not free MLD state.
499 *
500 * SMPng: Caller must hold IN6_MULTI_LOCK().
501 * Must take IF_ADDR_LOCK() to cover if_multiaddrs iterator.
502 * XXX This routine is also bitten by unlocked ifma_protospec access.
503 */
504 void
mld_ifdetach(struct ifnet * ifp,struct in6_multi_head * inmh)505 mld_ifdetach(struct ifnet *ifp, struct in6_multi_head *inmh)
506 {
507 struct epoch_tracker et;
508 struct mld_ifsoftc *mli;
509 struct ifmultiaddr *ifma;
510 struct in6_multi *inm;
511
512 CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp,
513 if_name(ifp));
514
515 IN6_MULTI_LIST_LOCK_ASSERT();
516 MLD_LOCK();
517
518 mli = MLD_IFINFO(ifp);
519 IF_ADDR_WLOCK(ifp);
520 /*
521 * Extract list of in6_multi associated with the detaching ifp
522 * which the PF_INET6 layer is about to release.
523 */
524 NET_EPOCH_ENTER(et);
525 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
526 inm = in6m_ifmultiaddr_get_inm(ifma);
527 if (inm == NULL)
528 continue;
529 in6m_disconnect_locked(inmh, inm);
530
531 if (mli->mli_version == MLD_VERSION_2) {
532 in6m_clear_recorded(inm);
533
534 /*
535 * We need to release the final reference held
536 * for issuing the INCLUDE {}.
537 */
538 if (inm->in6m_state == MLD_LEAVING_MEMBER) {
539 inm->in6m_state = MLD_NOT_MEMBER;
540 in6m_rele_locked(inmh, inm);
541 }
542 }
543 }
544 NET_EPOCH_EXIT(et);
545 IF_ADDR_WUNLOCK(ifp);
546 MLD_UNLOCK();
547 }
548
549 /*
550 * Hook for domifdetach.
551 * Runs after link-layer cleanup; free MLD state.
552 */
553 void
mld_domifdetach(struct ifnet * ifp)554 mld_domifdetach(struct ifnet *ifp)
555 {
556 struct mld_ifsoftc *mli = MLD_IFINFO(ifp);
557
558 CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
559 __func__, ifp, if_name(ifp));
560
561 MLD_LOCK();
562 LIST_REMOVE(mli, mli_link);
563 MLD_UNLOCK();
564 mbufq_drain(&mli->mli_gq);
565 }
566
567 /*
568 * Process a received MLDv1 general or address-specific query.
569 * Assumes that the query header has been pulled up to sizeof(mld_hdr).
570 *
571 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
572 * mld_addr. This is OK as we own the mbuf chain.
573 */
574 static int
mld_v1_input_query(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)575 mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
576 /*const*/ struct mld_hdr *mld)
577 {
578 struct ifmultiaddr *ifma;
579 struct mld_ifsoftc *mli;
580 struct in6_multi *inm;
581 int is_general_query;
582 uint16_t timer;
583 #ifdef KTR
584 char ip6tbuf[INET6_ADDRSTRLEN];
585 #endif
586
587 NET_EPOCH_ASSERT();
588
589 is_general_query = 0;
590
591 if (!V_mld_v1enable) {
592 CTR3(KTR_MLD, "ignore v1 query %s on ifp %p(%s)",
593 ip6_sprintf(ip6tbuf, &mld->mld_addr),
594 ifp, if_name(ifp));
595 return (0);
596 }
597
598 /*
599 * RFC3810 Section 6.2: MLD queries must originate from
600 * a router's link-local address.
601 */
602 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
603 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
604 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
605 ifp, if_name(ifp));
606 return (0);
607 }
608
609 /*
610 * Do address field validation upfront before we accept
611 * the query.
612 */
613 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
614 /*
615 * MLDv1 General Query.
616 * If this was not sent to the all-nodes group, ignore it.
617 */
618 struct in6_addr dst;
619
620 dst = ip6->ip6_dst;
621 in6_clearscope(&dst);
622 if (!IN6_ARE_ADDR_EQUAL(&dst, &in6addr_linklocal_allnodes))
623 return (EINVAL);
624 is_general_query = 1;
625 } else {
626 /*
627 * Embed scope ID of receiving interface in MLD query for
628 * lookup whilst we don't hold other locks.
629 */
630 in6_setscope(&mld->mld_addr, ifp, NULL);
631 }
632
633 IN6_MULTI_LIST_LOCK();
634 MLD_LOCK();
635
636 /*
637 * Switch to MLDv1 host compatibility mode.
638 */
639 mli = MLD_IFINFO(ifp);
640 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
641 mld_set_version(mli, MLD_VERSION_1);
642
643 timer = (ntohs(mld->mld_maxdelay) * MLD_FASTHZ) / MLD_TIMER_SCALE;
644 if (timer == 0)
645 timer = 1;
646
647 if (is_general_query) {
648 /*
649 * For each reporting group joined on this
650 * interface, kick the report timer.
651 */
652 CTR2(KTR_MLD, "process v1 general query on ifp %p(%s)",
653 ifp, if_name(ifp));
654 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
655 inm = in6m_ifmultiaddr_get_inm(ifma);
656 if (inm == NULL)
657 continue;
658 mld_v1_update_group(inm, timer);
659 }
660 } else {
661 /*
662 * MLDv1 Group-Specific Query.
663 * If this is a group-specific MLDv1 query, we need only
664 * look up the single group to process it.
665 */
666 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
667 if (inm != NULL) {
668 CTR3(KTR_MLD, "process v1 query %s on ifp %p(%s)",
669 ip6_sprintf(ip6tbuf, &mld->mld_addr),
670 ifp, if_name(ifp));
671 mld_v1_update_group(inm, timer);
672 }
673 /* XXX Clear embedded scope ID as userland won't expect it. */
674 in6_clearscope(&mld->mld_addr);
675 }
676
677 MLD_UNLOCK();
678 IN6_MULTI_LIST_UNLOCK();
679
680 return (0);
681 }
682
683 /*
684 * Update the report timer on a group in response to an MLDv1 query.
685 *
686 * If we are becoming the reporting member for this group, start the timer.
687 * If we already are the reporting member for this group, and timer is
688 * below the threshold, reset it.
689 *
690 * We may be updating the group for the first time since we switched
691 * to MLDv2. If we are, then we must clear any recorded source lists,
692 * and transition to REPORTING state; the group timer is overloaded
693 * for group and group-source query responses.
694 *
695 * Unlike MLDv2, the delay per group should be jittered
696 * to avoid bursts of MLDv1 reports.
697 */
698 static void
mld_v1_update_group(struct in6_multi * inm,const int timer)699 mld_v1_update_group(struct in6_multi *inm, const int timer)
700 {
701 #ifdef KTR
702 char ip6tbuf[INET6_ADDRSTRLEN];
703 #endif
704
705 CTR4(KTR_MLD, "%s: %s/%s timer=%d", __func__,
706 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
707 if_name(inm->in6m_ifp), timer);
708
709 IN6_MULTI_LIST_LOCK_ASSERT();
710
711 switch (inm->in6m_state) {
712 case MLD_NOT_MEMBER:
713 case MLD_SILENT_MEMBER:
714 break;
715 case MLD_REPORTING_MEMBER:
716 if (inm->in6m_timer != 0 &&
717 inm->in6m_timer <= timer) {
718 CTR1(KTR_MLD, "%s: REPORTING and timer running, "
719 "skipping.", __func__);
720 break;
721 }
722 /* FALLTHROUGH */
723 case MLD_SG_QUERY_PENDING_MEMBER:
724 case MLD_G_QUERY_PENDING_MEMBER:
725 case MLD_IDLE_MEMBER:
726 case MLD_LAZY_MEMBER:
727 case MLD_AWAKENING_MEMBER:
728 CTR1(KTR_MLD, "%s: ->REPORTING", __func__);
729 inm->in6m_state = MLD_REPORTING_MEMBER;
730 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
731 V_current_state_timers_running6 = 1;
732 break;
733 case MLD_SLEEPING_MEMBER:
734 CTR1(KTR_MLD, "%s: ->AWAKENING", __func__);
735 inm->in6m_state = MLD_AWAKENING_MEMBER;
736 break;
737 case MLD_LEAVING_MEMBER:
738 break;
739 }
740 }
741
742 /*
743 * Process a received MLDv2 general, group-specific or
744 * group-and-source-specific query.
745 *
746 * Assumes that mld points to a struct mldv2_query which is stored in
747 * contiguous memory.
748 *
749 * Return 0 if successful, otherwise an appropriate error code is returned.
750 */
751 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)752 mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
753 struct mbuf *m, struct mldv2_query *mld, const int off, const int icmp6len)
754 {
755 struct mld_ifsoftc *mli;
756 struct in6_multi *inm;
757 uint32_t maxdelay, nsrc, qqi;
758 int is_general_query;
759 uint16_t timer;
760 uint8_t qrv;
761 #ifdef KTR
762 char ip6tbuf[INET6_ADDRSTRLEN];
763 #endif
764
765 NET_EPOCH_ASSERT();
766
767 if (!V_mld_v2enable) {
768 CTR3(KTR_MLD, "ignore v2 query src %s on ifp %p(%s)",
769 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
770 ifp, if_name(ifp));
771 return (0);
772 }
773
774 /*
775 * RFC3810 Section 6.2: MLD queries must originate from
776 * a router's link-local address.
777 */
778 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
779 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
780 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
781 ifp, if_name(ifp));
782 return (0);
783 }
784
785 is_general_query = 0;
786
787 CTR2(KTR_MLD, "input v2 query on ifp %p(%s)", ifp, if_name(ifp));
788
789 maxdelay = ntohs(mld->mld_maxdelay); /* in 1/10ths of a second */
790 if (maxdelay >= 32768) {
791 maxdelay = (MLD_MRC_MANT(maxdelay) | 0x1000) <<
792 (MLD_MRC_EXP(maxdelay) + 3);
793 }
794 timer = (maxdelay * MLD_FASTHZ) / MLD_TIMER_SCALE;
795 if (timer == 0)
796 timer = 1;
797
798 qrv = MLD_QRV(mld->mld_misc);
799 if (qrv < 2) {
800 CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
801 qrv, MLD_RV_INIT);
802 qrv = MLD_RV_INIT;
803 }
804
805 qqi = mld->mld_qqi;
806 if (qqi >= 128) {
807 qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
808 (MLD_QQIC_EXP(mld->mld_qqi) + 3);
809 }
810
811 nsrc = ntohs(mld->mld_numsrc);
812 if (nsrc > MLD_MAX_GS_SOURCES)
813 return (EMSGSIZE);
814 if (icmp6len < sizeof(struct mldv2_query) +
815 (nsrc * sizeof(struct in6_addr)))
816 return (EMSGSIZE);
817
818 /*
819 * Do further input validation upfront to avoid resetting timers
820 * should we need to discard this query.
821 */
822 if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
823 /*
824 * A general query with a source list has undefined
825 * behaviour; discard it.
826 */
827 if (nsrc > 0)
828 return (EINVAL);
829 is_general_query = 1;
830 } else {
831 /*
832 * Embed scope ID of receiving interface in MLD query for
833 * lookup whilst we don't hold other locks (due to KAME
834 * locking lameness). We own this mbuf chain just now.
835 */
836 in6_setscope(&mld->mld_addr, ifp, NULL);
837 }
838
839 IN6_MULTI_LIST_LOCK();
840 MLD_LOCK();
841
842 mli = MLD_IFINFO(ifp);
843 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
844
845 /*
846 * Discard the v2 query if we're in Compatibility Mode.
847 * The RFC is pretty clear that hosts need to stay in MLDv1 mode
848 * until the Old Version Querier Present timer expires.
849 */
850 if (mli->mli_version != MLD_VERSION_2)
851 goto out_locked;
852
853 mld_set_version(mli, MLD_VERSION_2);
854 mli->mli_rv = qrv;
855 mli->mli_qi = qqi;
856 mli->mli_qri = maxdelay;
857
858 CTR4(KTR_MLD, "%s: qrv %d qi %d maxdelay %d", __func__, qrv, qqi,
859 maxdelay);
860
861 if (is_general_query) {
862 /*
863 * MLDv2 General Query.
864 *
865 * Schedule a current-state report on this ifp for
866 * all groups, possibly containing source lists.
867 *
868 * If there is a pending General Query response
869 * scheduled earlier than the selected delay, do
870 * not schedule any other reports.
871 * Otherwise, reset the interface timer.
872 */
873 CTR2(KTR_MLD, "process v2 general query on ifp %p(%s)",
874 ifp, if_name(ifp));
875 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer) {
876 mli->mli_v2_timer = MLD_RANDOM_DELAY(timer);
877 V_interface_timers_running6 = 1;
878 }
879 } else {
880 /*
881 * MLDv2 Group-specific or Group-and-source-specific Query.
882 *
883 * Group-source-specific queries are throttled on
884 * a per-group basis to defeat denial-of-service attempts.
885 * Queries for groups we are not a member of on this
886 * link are simply ignored.
887 */
888 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
889 if (inm == NULL)
890 goto out_locked;
891 if (nsrc > 0) {
892 if (!ratecheck(&inm->in6m_lastgsrtv,
893 &V_mld_gsrdelay)) {
894 CTR1(KTR_MLD, "%s: GS query throttled.",
895 __func__);
896 goto out_locked;
897 }
898 }
899 CTR2(KTR_MLD, "process v2 group query on ifp %p(%s)",
900 ifp, if_name(ifp));
901 /*
902 * If there is a pending General Query response
903 * scheduled sooner than the selected delay, no
904 * further report need be scheduled.
905 * Otherwise, prepare to respond to the
906 * group-specific or group-and-source query.
907 */
908 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer)
909 mld_v2_process_group_query(inm, mli, timer, m, mld, off);
910
911 /* XXX Clear embedded scope ID as userland won't expect it. */
912 in6_clearscope(&mld->mld_addr);
913 }
914
915 out_locked:
916 MLD_UNLOCK();
917 IN6_MULTI_LIST_UNLOCK();
918
919 return (0);
920 }
921
922 /*
923 * Process a received MLDv2 group-specific or group-and-source-specific
924 * query.
925 * Return <0 if any error occurred. Currently this is ignored.
926 */
927 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)928 mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifsoftc *mli,
929 int timer, struct mbuf *m0, struct mldv2_query *mld, const int off)
930 {
931 int retval;
932 uint16_t nsrc;
933
934 IN6_MULTI_LIST_LOCK_ASSERT();
935 MLD_LOCK_ASSERT();
936
937 retval = 0;
938
939 switch (inm->in6m_state) {
940 case MLD_NOT_MEMBER:
941 case MLD_SILENT_MEMBER:
942 case MLD_SLEEPING_MEMBER:
943 case MLD_LAZY_MEMBER:
944 case MLD_AWAKENING_MEMBER:
945 case MLD_IDLE_MEMBER:
946 case MLD_LEAVING_MEMBER:
947 return (retval);
948 break;
949 case MLD_REPORTING_MEMBER:
950 case MLD_G_QUERY_PENDING_MEMBER:
951 case MLD_SG_QUERY_PENDING_MEMBER:
952 break;
953 }
954
955 nsrc = ntohs(mld->mld_numsrc);
956
957 /* Length should be checked by calling function. */
958 KASSERT((m0->m_flags & M_PKTHDR) == 0 ||
959 m0->m_pkthdr.len >= off + sizeof(struct mldv2_query) +
960 nsrc * sizeof(struct in6_addr),
961 ("mldv2 packet is too short: (%d bytes < %zd bytes, m=%p)",
962 m0->m_pkthdr.len, off + sizeof(struct mldv2_query) +
963 nsrc * sizeof(struct in6_addr), m0));
964
965 /*
966 * Deal with group-specific queries upfront.
967 * If any group query is already pending, purge any recorded
968 * source-list state if it exists, and schedule a query response
969 * for this group-specific query.
970 */
971 if (nsrc == 0) {
972 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
973 inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER) {
974 in6m_clear_recorded(inm);
975 timer = min(inm->in6m_timer, timer);
976 }
977 inm->in6m_state = MLD_G_QUERY_PENDING_MEMBER;
978 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
979 V_current_state_timers_running6 = 1;
980 return (retval);
981 }
982
983 /*
984 * Deal with the case where a group-and-source-specific query has
985 * been received but a group-specific query is already pending.
986 */
987 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER) {
988 timer = min(inm->in6m_timer, timer);
989 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
990 V_current_state_timers_running6 = 1;
991 return (retval);
992 }
993
994 /*
995 * Finally, deal with the case where a group-and-source-specific
996 * query has been received, where a response to a previous g-s-r
997 * query exists, or none exists.
998 * In this case, we need to parse the source-list which the Querier
999 * has provided us with and check if we have any source list filter
1000 * entries at T1 for these sources. If we do not, there is no need
1001 * schedule a report and the query may be dropped.
1002 * If we do, we must record them and schedule a current-state
1003 * report for those sources.
1004 */
1005 if (inm->in6m_nsrc > 0) {
1006 struct in6_addr srcaddr;
1007 int i, nrecorded;
1008 int soff;
1009
1010 soff = off + sizeof(struct mldv2_query);
1011 nrecorded = 0;
1012 for (i = 0; i < nsrc; i++) {
1013 m_copydata(m0, soff, sizeof(struct in6_addr),
1014 (caddr_t)&srcaddr);
1015 retval = in6m_record_source(inm, &srcaddr);
1016 if (retval < 0)
1017 break;
1018 nrecorded += retval;
1019 soff += sizeof(struct in6_addr);
1020 }
1021 if (nrecorded > 0) {
1022 CTR1(KTR_MLD,
1023 "%s: schedule response to SG query", __func__);
1024 inm->in6m_state = MLD_SG_QUERY_PENDING_MEMBER;
1025 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1026 V_current_state_timers_running6 = 1;
1027 }
1028 }
1029
1030 return (retval);
1031 }
1032
1033 /*
1034 * Process a received MLDv1 host membership report.
1035 * Assumes mld points to mld_hdr in pulled up mbuf chain.
1036 *
1037 * NOTE: Can't be fully const correct as we temporarily embed scope ID in
1038 * mld_addr. This is OK as we own the mbuf chain.
1039 */
1040 static int
mld_v1_input_report(struct ifnet * ifp,const struct ip6_hdr * ip6,struct mld_hdr * mld)1041 mld_v1_input_report(struct ifnet *ifp, const struct ip6_hdr *ip6,
1042 /*const*/ struct mld_hdr *mld)
1043 {
1044 struct in6_addr src, dst;
1045 struct in6_ifaddr *ia;
1046 struct in6_multi *inm;
1047 #ifdef KTR
1048 char ip6tbuf[INET6_ADDRSTRLEN];
1049 #endif
1050
1051 NET_EPOCH_ASSERT();
1052
1053 if (!V_mld_v1enable) {
1054 CTR3(KTR_MLD, "ignore v1 report %s on ifp %p(%s)",
1055 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1056 ifp, if_name(ifp));
1057 return (0);
1058 }
1059
1060 if (ifp->if_flags & IFF_LOOPBACK)
1061 return (0);
1062
1063 /*
1064 * MLDv1 reports must originate from a host's link-local address,
1065 * or the unspecified address (when booting).
1066 */
1067 src = ip6->ip6_src;
1068 in6_clearscope(&src);
1069 if (!IN6_IS_SCOPE_LINKLOCAL(&src) && !IN6_IS_ADDR_UNSPECIFIED(&src)) {
1070 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
1071 ip6_sprintf(ip6tbuf, &ip6->ip6_src),
1072 ifp, if_name(ifp));
1073 return (EINVAL);
1074 }
1075
1076 /*
1077 * RFC2710 Section 4: MLDv1 reports must pertain to a multicast
1078 * group, and must be directed to the group itself.
1079 */
1080 dst = ip6->ip6_dst;
1081 in6_clearscope(&dst);
1082 if (!IN6_IS_ADDR_MULTICAST(&mld->mld_addr) ||
1083 !IN6_ARE_ADDR_EQUAL(&mld->mld_addr, &dst)) {
1084 CTR3(KTR_MLD, "ignore v1 query dst %s on ifp %p(%s)",
1085 ip6_sprintf(ip6tbuf, &ip6->ip6_dst),
1086 ifp, if_name(ifp));
1087 return (EINVAL);
1088 }
1089
1090 /*
1091 * Make sure we don't hear our own membership report, as fast
1092 * leave requires knowing that we are the only member of a
1093 * group. Assume we used the link-local address if available,
1094 * otherwise look for ::.
1095 *
1096 * XXX Note that scope ID comparison is needed for the address
1097 * returned by in6ifa_ifpforlinklocal(), but SHOULD NOT be
1098 * performed for the on-wire address.
1099 */
1100 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1101 if ((ia && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, IA6_IN6(ia))) ||
1102 (ia == NULL && IN6_IS_ADDR_UNSPECIFIED(&src))) {
1103 if (ia != NULL)
1104 ifa_free(&ia->ia_ifa);
1105 return (0);
1106 }
1107 if (ia != NULL)
1108 ifa_free(&ia->ia_ifa);
1109
1110 CTR3(KTR_MLD, "process v1 report %s on ifp %p(%s)",
1111 ip6_sprintf(ip6tbuf, &mld->mld_addr), ifp, if_name(ifp));
1112
1113 /*
1114 * Embed scope ID of receiving interface in MLD query for lookup
1115 * whilst we don't hold other locks (due to KAME locking lameness).
1116 */
1117 if (!IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr))
1118 in6_setscope(&mld->mld_addr, ifp, NULL);
1119
1120 IN6_MULTI_LIST_LOCK();
1121 MLD_LOCK();
1122
1123 /*
1124 * MLDv1 report suppression.
1125 * If we are a member of this group, and our membership should be
1126 * reported, and our group timer is pending or about to be reset,
1127 * stop our group timer by transitioning to the 'lazy' state.
1128 */
1129 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
1130 if (inm != NULL) {
1131 struct mld_ifsoftc *mli;
1132
1133 mli = inm->in6m_mli;
1134 KASSERT(mli != NULL,
1135 ("%s: no mli for ifp %p", __func__, ifp));
1136
1137 /*
1138 * If we are in MLDv2 host mode, do not allow the
1139 * other host's MLDv1 report to suppress our reports.
1140 */
1141 if (mli->mli_version == MLD_VERSION_2)
1142 goto out_locked;
1143
1144 inm->in6m_timer = 0;
1145
1146 switch (inm->in6m_state) {
1147 case MLD_NOT_MEMBER:
1148 case MLD_SILENT_MEMBER:
1149 case MLD_SLEEPING_MEMBER:
1150 break;
1151 case MLD_REPORTING_MEMBER:
1152 case MLD_IDLE_MEMBER:
1153 case MLD_AWAKENING_MEMBER:
1154 CTR3(KTR_MLD,
1155 "report suppressed for %s on ifp %p(%s)",
1156 ip6_sprintf(ip6tbuf, &mld->mld_addr),
1157 ifp, if_name(ifp));
1158 case MLD_LAZY_MEMBER:
1159 inm->in6m_state = MLD_LAZY_MEMBER;
1160 break;
1161 case MLD_G_QUERY_PENDING_MEMBER:
1162 case MLD_SG_QUERY_PENDING_MEMBER:
1163 case MLD_LEAVING_MEMBER:
1164 break;
1165 }
1166 }
1167
1168 out_locked:
1169 MLD_UNLOCK();
1170 IN6_MULTI_LIST_UNLOCK();
1171
1172 /* XXX Clear embedded scope ID as userland won't expect it. */
1173 in6_clearscope(&mld->mld_addr);
1174
1175 return (0);
1176 }
1177
1178 /*
1179 * MLD input path.
1180 *
1181 * Assume query messages which fit in a single ICMPv6 message header
1182 * have been pulled up.
1183 * Assume that userland will want to see the message, even if it
1184 * otherwise fails kernel input validation; do not free it.
1185 * Pullup may however free the mbuf chain m if it fails.
1186 *
1187 * Return IPPROTO_DONE if we freed m. Otherwise, return 0.
1188 */
1189 int
mld_input(struct mbuf ** mp,int off,int icmp6len)1190 mld_input(struct mbuf **mp, int off, int icmp6len)
1191 {
1192 struct ifnet *ifp;
1193 struct ip6_hdr *ip6;
1194 struct mbuf *m;
1195 struct mld_hdr *mld;
1196 int mldlen;
1197
1198 m = *mp;
1199 CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
1200
1201 ifp = m->m_pkthdr.rcvif;
1202
1203 /* Pullup to appropriate size. */
1204 if (m->m_len < off + sizeof(*mld)) {
1205 m = m_pullup(m, off + sizeof(*mld));
1206 if (m == NULL) {
1207 ICMP6STAT_INC(icp6s_badlen);
1208 return (IPPROTO_DONE);
1209 }
1210 }
1211 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1212 if (mld->mld_type == MLD_LISTENER_QUERY &&
1213 icmp6len >= sizeof(struct mldv2_query)) {
1214 mldlen = sizeof(struct mldv2_query);
1215 } else {
1216 mldlen = sizeof(struct mld_hdr);
1217 }
1218 if (m->m_len < off + mldlen) {
1219 m = m_pullup(m, off + mldlen);
1220 if (m == NULL) {
1221 ICMP6STAT_INC(icp6s_badlen);
1222 return (IPPROTO_DONE);
1223 }
1224 }
1225 *mp = m;
1226 ip6 = mtod(m, struct ip6_hdr *);
1227 mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1228
1229 /*
1230 * Userland needs to see all of this traffic for implementing
1231 * the endpoint discovery portion of multicast routing.
1232 */
1233 switch (mld->mld_type) {
1234 case MLD_LISTENER_QUERY:
1235 icmp6_ifstat_inc(ifp, ifs6_in_mldquery);
1236 if (icmp6len == sizeof(struct mld_hdr)) {
1237 if (mld_v1_input_query(ifp, ip6, mld) != 0)
1238 return (0);
1239 } else if (icmp6len >= sizeof(struct mldv2_query)) {
1240 if (mld_v2_input_query(ifp, ip6, m,
1241 (struct mldv2_query *)mld, off, icmp6len) != 0)
1242 return (0);
1243 }
1244 break;
1245 case MLD_LISTENER_REPORT:
1246 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1247 if (mld_v1_input_report(ifp, ip6, mld) != 0)
1248 return (0);
1249 break;
1250 case MLDV2_LISTENER_REPORT:
1251 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1252 break;
1253 case MLD_LISTENER_DONE:
1254 icmp6_ifstat_inc(ifp, ifs6_in_mlddone);
1255 break;
1256 default:
1257 break;
1258 }
1259
1260 return (0);
1261 }
1262
1263 /*
1264 * Fast timeout handler (global).
1265 * VIMAGE: Timeout handlers are expected to service all vimages.
1266 */
1267 static struct callout mldfast_callout;
1268 static void
mld_fasttimo(void * arg __unused)1269 mld_fasttimo(void *arg __unused)
1270 {
1271 struct epoch_tracker et;
1272 struct in6_multi_head inmh;
1273 VNET_ITERATOR_DECL(vnet_iter);
1274
1275 SLIST_INIT(&inmh);
1276
1277 NET_EPOCH_ENTER(et);
1278 VNET_LIST_RLOCK_NOSLEEP();
1279 VNET_FOREACH(vnet_iter) {
1280 CURVNET_SET(vnet_iter);
1281 mld_fasttimo_vnet(&inmh);
1282 CURVNET_RESTORE();
1283 }
1284 VNET_LIST_RUNLOCK_NOSLEEP();
1285 NET_EPOCH_EXIT(et);
1286 in6m_release_list_deferred(&inmh);
1287
1288 callout_reset(&mldfast_callout, hz / MLD_FASTHZ, mld_fasttimo, NULL);
1289 }
1290
1291 /*
1292 * Fast timeout handler (per-vnet).
1293 *
1294 * VIMAGE: Assume caller has set up our curvnet.
1295 */
1296 static void
mld_fasttimo_vnet(struct in6_multi_head * inmh)1297 mld_fasttimo_vnet(struct in6_multi_head *inmh)
1298 {
1299 struct mbufq scq; /* State-change packets */
1300 struct mbufq qrq; /* Query response packets */
1301 struct ifnet *ifp;
1302 struct mld_ifsoftc *mli;
1303 struct ifmultiaddr *ifma;
1304 struct in6_multi *inm;
1305 int uri_fasthz;
1306
1307 uri_fasthz = 0;
1308
1309 /*
1310 * Quick check to see if any work needs to be done, in order to
1311 * minimize the overhead of fasttimo processing.
1312 * SMPng: XXX Unlocked reads.
1313 */
1314 if (!V_current_state_timers_running6 &&
1315 !V_interface_timers_running6 &&
1316 !V_state_change_timers_running6)
1317 return;
1318
1319 IN6_MULTI_LIST_LOCK();
1320 MLD_LOCK();
1321
1322 /*
1323 * MLDv2 General Query response timer processing.
1324 */
1325 if (V_interface_timers_running6) {
1326 CTR1(KTR_MLD, "%s: interface timers running", __func__);
1327
1328 V_interface_timers_running6 = 0;
1329 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1330 if (mli->mli_v2_timer == 0) {
1331 /* Do nothing. */
1332 } else if (--mli->mli_v2_timer == 0) {
1333 mld_v2_dispatch_general_query(mli);
1334 } else {
1335 V_interface_timers_running6 = 1;
1336 }
1337 }
1338 }
1339
1340 if (!V_current_state_timers_running6 &&
1341 !V_state_change_timers_running6)
1342 goto out_locked;
1343
1344 V_current_state_timers_running6 = 0;
1345 V_state_change_timers_running6 = 0;
1346
1347 CTR1(KTR_MLD, "%s: state change timers running", __func__);
1348
1349 /*
1350 * MLD host report and state-change timer processing.
1351 * Note: Processing a v2 group timer may remove a node.
1352 */
1353 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1354 ifp = mli->mli_ifp;
1355
1356 if (mli->mli_version == MLD_VERSION_2) {
1357 uri_fasthz = MLD_RANDOM_DELAY(mli->mli_uri *
1358 MLD_FASTHZ);
1359 mbufq_init(&qrq, MLD_MAX_G_GS_PACKETS);
1360 mbufq_init(&scq, MLD_MAX_STATE_CHANGE_PACKETS);
1361 }
1362
1363 IF_ADDR_WLOCK(ifp);
1364 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1365 inm = in6m_ifmultiaddr_get_inm(ifma);
1366 if (inm == NULL)
1367 continue;
1368 switch (mli->mli_version) {
1369 case MLD_VERSION_1:
1370 mld_v1_process_group_timer(inmh, inm);
1371 break;
1372 case MLD_VERSION_2:
1373 mld_v2_process_group_timers(inmh, &qrq,
1374 &scq, inm, uri_fasthz);
1375 break;
1376 }
1377 }
1378 IF_ADDR_WUNLOCK(ifp);
1379
1380 switch (mli->mli_version) {
1381 case MLD_VERSION_1:
1382 /*
1383 * Transmit reports for this lifecycle. This
1384 * is done while not holding IF_ADDR_LOCK
1385 * since this can call
1386 * in6ifa_ifpforlinklocal() which locks
1387 * IF_ADDR_LOCK internally as well as
1388 * ip6_output() to transmit a packet.
1389 */
1390 while ((inm = SLIST_FIRST(inmh)) != NULL) {
1391 SLIST_REMOVE_HEAD(inmh, in6m_defer);
1392 (void)mld_v1_transmit_report(inm,
1393 MLD_LISTENER_REPORT);
1394 }
1395 break;
1396 case MLD_VERSION_2:
1397 mld_dispatch_queue(&qrq, 0);
1398 mld_dispatch_queue(&scq, 0);
1399 break;
1400 }
1401 }
1402
1403 out_locked:
1404 MLD_UNLOCK();
1405 IN6_MULTI_LIST_UNLOCK();
1406 }
1407
1408 /*
1409 * Update host report group timer.
1410 * Will update the global pending timer flags.
1411 */
1412 static void
mld_v1_process_group_timer(struct in6_multi_head * inmh,struct in6_multi * inm)1413 mld_v1_process_group_timer(struct in6_multi_head *inmh, struct in6_multi *inm)
1414 {
1415 int report_timer_expired;
1416
1417 IN6_MULTI_LIST_LOCK_ASSERT();
1418 MLD_LOCK_ASSERT();
1419
1420 if (inm->in6m_timer == 0) {
1421 report_timer_expired = 0;
1422 } else if (--inm->in6m_timer == 0) {
1423 report_timer_expired = 1;
1424 } else {
1425 V_current_state_timers_running6 = 1;
1426 return;
1427 }
1428
1429 switch (inm->in6m_state) {
1430 case MLD_NOT_MEMBER:
1431 case MLD_SILENT_MEMBER:
1432 case MLD_IDLE_MEMBER:
1433 case MLD_LAZY_MEMBER:
1434 case MLD_SLEEPING_MEMBER:
1435 case MLD_AWAKENING_MEMBER:
1436 break;
1437 case MLD_REPORTING_MEMBER:
1438 if (report_timer_expired) {
1439 inm->in6m_state = MLD_IDLE_MEMBER;
1440 SLIST_INSERT_HEAD(inmh, inm, in6m_defer);
1441 }
1442 break;
1443 case MLD_G_QUERY_PENDING_MEMBER:
1444 case MLD_SG_QUERY_PENDING_MEMBER:
1445 case MLD_LEAVING_MEMBER:
1446 break;
1447 }
1448 }
1449
1450 /*
1451 * Update a group's timers for MLDv2.
1452 * Will update the global pending timer flags.
1453 * Note: Unlocked read from mli.
1454 */
1455 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)1456 mld_v2_process_group_timers(struct in6_multi_head *inmh,
1457 struct mbufq *qrq, struct mbufq *scq,
1458 struct in6_multi *inm, const int uri_fasthz)
1459 {
1460 int query_response_timer_expired;
1461 int state_change_retransmit_timer_expired;
1462 #ifdef KTR
1463 char ip6tbuf[INET6_ADDRSTRLEN];
1464 #endif
1465
1466 IN6_MULTI_LIST_LOCK_ASSERT();
1467 MLD_LOCK_ASSERT();
1468
1469 query_response_timer_expired = 0;
1470 state_change_retransmit_timer_expired = 0;
1471
1472 /*
1473 * During a transition from compatibility mode back to MLDv2,
1474 * a group record in REPORTING state may still have its group
1475 * timer active. This is a no-op in this function; it is easier
1476 * to deal with it here than to complicate the slow-timeout path.
1477 */
1478 if (inm->in6m_timer == 0) {
1479 query_response_timer_expired = 0;
1480 } else if (--inm->in6m_timer == 0) {
1481 query_response_timer_expired = 1;
1482 } else {
1483 V_current_state_timers_running6 = 1;
1484 }
1485
1486 if (inm->in6m_sctimer == 0) {
1487 state_change_retransmit_timer_expired = 0;
1488 } else if (--inm->in6m_sctimer == 0) {
1489 state_change_retransmit_timer_expired = 1;
1490 } else {
1491 V_state_change_timers_running6 = 1;
1492 }
1493
1494 /* We are in fasttimo, so be quick about it. */
1495 if (!state_change_retransmit_timer_expired &&
1496 !query_response_timer_expired)
1497 return;
1498
1499 switch (inm->in6m_state) {
1500 case MLD_NOT_MEMBER:
1501 case MLD_SILENT_MEMBER:
1502 case MLD_SLEEPING_MEMBER:
1503 case MLD_LAZY_MEMBER:
1504 case MLD_AWAKENING_MEMBER:
1505 case MLD_IDLE_MEMBER:
1506 break;
1507 case MLD_G_QUERY_PENDING_MEMBER:
1508 case MLD_SG_QUERY_PENDING_MEMBER:
1509 /*
1510 * Respond to a previously pending Group-Specific
1511 * or Group-and-Source-Specific query by enqueueing
1512 * the appropriate Current-State report for
1513 * immediate transmission.
1514 */
1515 if (query_response_timer_expired) {
1516 int retval __unused;
1517
1518 retval = mld_v2_enqueue_group_record(qrq, inm, 0, 1,
1519 (inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER),
1520 0);
1521 CTR2(KTR_MLD, "%s: enqueue record = %d",
1522 __func__, retval);
1523 inm->in6m_state = MLD_REPORTING_MEMBER;
1524 in6m_clear_recorded(inm);
1525 }
1526 /* FALLTHROUGH */
1527 case MLD_REPORTING_MEMBER:
1528 case MLD_LEAVING_MEMBER:
1529 if (state_change_retransmit_timer_expired) {
1530 /*
1531 * State-change retransmission timer fired.
1532 * If there are any further pending retransmissions,
1533 * set the global pending state-change flag, and
1534 * reset the timer.
1535 */
1536 if (--inm->in6m_scrv > 0) {
1537 inm->in6m_sctimer = uri_fasthz;
1538 V_state_change_timers_running6 = 1;
1539 }
1540 /*
1541 * Retransmit the previously computed state-change
1542 * report. If there are no further pending
1543 * retransmissions, the mbuf queue will be consumed.
1544 * Update T0 state to T1 as we have now sent
1545 * a state-change.
1546 */
1547 (void)mld_v2_merge_state_changes(inm, scq);
1548
1549 in6m_commit(inm);
1550 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
1551 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1552 if_name(inm->in6m_ifp));
1553
1554 /*
1555 * If we are leaving the group for good, make sure
1556 * we release MLD's reference to it.
1557 * This release must be deferred using a SLIST,
1558 * as we are called from a loop which traverses
1559 * the in_ifmultiaddr TAILQ.
1560 */
1561 if (inm->in6m_state == MLD_LEAVING_MEMBER &&
1562 inm->in6m_scrv == 0) {
1563 inm->in6m_state = MLD_NOT_MEMBER;
1564 in6m_disconnect_locked(inmh, inm);
1565 in6m_rele_locked(inmh, inm);
1566 }
1567 }
1568 break;
1569 }
1570 }
1571
1572 /*
1573 * Switch to a different version on the given interface,
1574 * as per Section 9.12.
1575 */
1576 static void
mld_set_version(struct mld_ifsoftc * mli,const int version)1577 mld_set_version(struct mld_ifsoftc *mli, const int version)
1578 {
1579 int old_version_timer;
1580
1581 MLD_LOCK_ASSERT();
1582
1583 CTR4(KTR_MLD, "%s: switching to v%d on ifp %p(%s)", __func__,
1584 version, mli->mli_ifp, if_name(mli->mli_ifp));
1585
1586 if (version == MLD_VERSION_1) {
1587 /*
1588 * Compute the "Older Version Querier Present" timer as per
1589 * Section 9.12.
1590 */
1591 old_version_timer = (mli->mli_rv * mli->mli_qi) + mli->mli_qri;
1592 old_version_timer *= MLD_SLOWHZ;
1593 mli->mli_v1_timer = old_version_timer;
1594 }
1595
1596 if (mli->mli_v1_timer > 0 && mli->mli_version != MLD_VERSION_1) {
1597 mli->mli_version = MLD_VERSION_1;
1598 mld_v2_cancel_link_timers(mli);
1599 }
1600 }
1601
1602 /*
1603 * Cancel pending MLDv2 timers for the given link and all groups
1604 * joined on it; state-change, general-query, and group-query timers.
1605 */
1606 static void
mld_v2_cancel_link_timers(struct mld_ifsoftc * mli)1607 mld_v2_cancel_link_timers(struct mld_ifsoftc *mli)
1608 {
1609 struct epoch_tracker et;
1610 struct in6_multi_head inmh;
1611 struct ifmultiaddr *ifma;
1612 struct ifnet *ifp;
1613 struct in6_multi *inm;
1614
1615 CTR3(KTR_MLD, "%s: cancel v2 timers on ifp %p(%s)", __func__,
1616 mli->mli_ifp, if_name(mli->mli_ifp));
1617
1618 SLIST_INIT(&inmh);
1619 IN6_MULTI_LIST_LOCK_ASSERT();
1620 MLD_LOCK_ASSERT();
1621
1622 /*
1623 * Fast-track this potentially expensive operation
1624 * by checking all the global 'timer pending' flags.
1625 */
1626 if (!V_interface_timers_running6 &&
1627 !V_state_change_timers_running6 &&
1628 !V_current_state_timers_running6)
1629 return;
1630
1631 mli->mli_v2_timer = 0;
1632
1633 ifp = mli->mli_ifp;
1634
1635 IF_ADDR_WLOCK(ifp);
1636 NET_EPOCH_ENTER(et);
1637 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1638 inm = in6m_ifmultiaddr_get_inm(ifma);
1639 if (inm == NULL)
1640 continue;
1641 switch (inm->in6m_state) {
1642 case MLD_NOT_MEMBER:
1643 case MLD_SILENT_MEMBER:
1644 case MLD_IDLE_MEMBER:
1645 case MLD_LAZY_MEMBER:
1646 case MLD_SLEEPING_MEMBER:
1647 case MLD_AWAKENING_MEMBER:
1648 break;
1649 case MLD_LEAVING_MEMBER:
1650 /*
1651 * If we are leaving the group and switching
1652 * version, we need to release the final
1653 * reference held for issuing the INCLUDE {}.
1654 */
1655 if (inm->in6m_refcount == 1)
1656 in6m_disconnect_locked(&inmh, inm);
1657 in6m_rele_locked(&inmh, inm);
1658 /* FALLTHROUGH */
1659 case MLD_G_QUERY_PENDING_MEMBER:
1660 case MLD_SG_QUERY_PENDING_MEMBER:
1661 in6m_clear_recorded(inm);
1662 /* FALLTHROUGH */
1663 case MLD_REPORTING_MEMBER:
1664 inm->in6m_sctimer = 0;
1665 inm->in6m_timer = 0;
1666 inm->in6m_state = MLD_REPORTING_MEMBER;
1667 /*
1668 * Free any pending MLDv2 state-change records.
1669 */
1670 mbufq_drain(&inm->in6m_scq);
1671 break;
1672 }
1673 }
1674 NET_EPOCH_EXIT(et);
1675 IF_ADDR_WUNLOCK(ifp);
1676 in6m_release_list_deferred(&inmh);
1677 }
1678
1679 /*
1680 * Global slowtimo handler.
1681 * VIMAGE: Timeout handlers are expected to service all vimages.
1682 */
1683 static struct callout mldslow_callout;
1684 static void
mld_slowtimo(void * arg __unused)1685 mld_slowtimo(void *arg __unused)
1686 {
1687 VNET_ITERATOR_DECL(vnet_iter);
1688
1689 VNET_LIST_RLOCK_NOSLEEP();
1690 VNET_FOREACH(vnet_iter) {
1691 CURVNET_SET(vnet_iter);
1692 mld_slowtimo_vnet();
1693 CURVNET_RESTORE();
1694 }
1695 VNET_LIST_RUNLOCK_NOSLEEP();
1696
1697 callout_reset(&mldslow_callout, hz / MLD_SLOWHZ, mld_slowtimo, NULL);
1698 }
1699
1700 /*
1701 * Per-vnet slowtimo handler.
1702 */
1703 static void
mld_slowtimo_vnet(void)1704 mld_slowtimo_vnet(void)
1705 {
1706 struct mld_ifsoftc *mli;
1707
1708 MLD_LOCK();
1709
1710 LIST_FOREACH(mli, &V_mli_head, mli_link) {
1711 mld_v1_process_querier_timers(mli);
1712 }
1713
1714 MLD_UNLOCK();
1715 }
1716
1717 /*
1718 * Update the Older Version Querier Present timers for a link.
1719 * See Section 9.12 of RFC 3810.
1720 */
1721 static void
mld_v1_process_querier_timers(struct mld_ifsoftc * mli)1722 mld_v1_process_querier_timers(struct mld_ifsoftc *mli)
1723 {
1724
1725 MLD_LOCK_ASSERT();
1726
1727 if (mli->mli_version != MLD_VERSION_2 && --mli->mli_v1_timer == 0) {
1728 /*
1729 * MLDv1 Querier Present timer expired; revert to MLDv2.
1730 */
1731 CTR5(KTR_MLD,
1732 "%s: transition from v%d -> v%d on %p(%s)",
1733 __func__, mli->mli_version, MLD_VERSION_2,
1734 mli->mli_ifp, if_name(mli->mli_ifp));
1735 mli->mli_version = MLD_VERSION_2;
1736 }
1737 }
1738
1739 /*
1740 * Transmit an MLDv1 report immediately.
1741 */
1742 static int
mld_v1_transmit_report(struct in6_multi * in6m,const int type)1743 mld_v1_transmit_report(struct in6_multi *in6m, const int type)
1744 {
1745 struct ifnet *ifp;
1746 struct in6_ifaddr *ia;
1747 struct ip6_hdr *ip6;
1748 struct mbuf *mh, *md;
1749 struct mld_hdr *mld;
1750
1751 NET_EPOCH_ASSERT();
1752 IN6_MULTI_LIST_LOCK_ASSERT();
1753 MLD_LOCK_ASSERT();
1754
1755 ifp = in6m->in6m_ifp;
1756 /* in process of being freed */
1757 if (ifp == NULL)
1758 return (0);
1759 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1760 /* ia may be NULL if link-local address is tentative. */
1761
1762 mh = m_gethdr(M_NOWAIT, MT_DATA);
1763 if (mh == NULL) {
1764 if (ia != NULL)
1765 ifa_free(&ia->ia_ifa);
1766 return (ENOMEM);
1767 }
1768 md = m_get(M_NOWAIT, MT_DATA);
1769 if (md == NULL) {
1770 m_free(mh);
1771 if (ia != NULL)
1772 ifa_free(&ia->ia_ifa);
1773 return (ENOMEM);
1774 }
1775 mh->m_next = md;
1776
1777 /*
1778 * FUTURE: Consider increasing alignment by ETHER_HDR_LEN, so
1779 * that ether_output() does not need to allocate another mbuf
1780 * for the header in the most common case.
1781 */
1782 M_ALIGN(mh, sizeof(struct ip6_hdr));
1783 mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
1784 mh->m_len = sizeof(struct ip6_hdr);
1785
1786 ip6 = mtod(mh, struct ip6_hdr *);
1787 ip6->ip6_flow = 0;
1788 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1789 ip6->ip6_vfc |= IPV6_VERSION;
1790 ip6->ip6_nxt = IPPROTO_ICMPV6;
1791 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
1792 ip6->ip6_dst = in6m->in6m_addr;
1793
1794 md->m_len = sizeof(struct mld_hdr);
1795 mld = mtod(md, struct mld_hdr *);
1796 mld->mld_type = type;
1797 mld->mld_code = 0;
1798 mld->mld_cksum = 0;
1799 mld->mld_maxdelay = 0;
1800 mld->mld_reserved = 0;
1801 mld->mld_addr = in6m->in6m_addr;
1802 in6_clearscope(&mld->mld_addr);
1803 mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
1804 sizeof(struct ip6_hdr), sizeof(struct mld_hdr));
1805
1806 mld_save_context(mh, ifp);
1807 mh->m_flags |= M_MLDV1;
1808
1809 mld_dispatch_packet(mh);
1810
1811 if (ia != NULL)
1812 ifa_free(&ia->ia_ifa);
1813 return (0);
1814 }
1815
1816 /*
1817 * Process a state change from the upper layer for the given IPv6 group.
1818 *
1819 * Each socket holds a reference on the in_multi in its own ip_moptions.
1820 * The socket layer will have made the necessary updates to.the group
1821 * state, it is now up to MLD to issue a state change report if there
1822 * has been any change between T0 (when the last state-change was issued)
1823 * and T1 (now).
1824 *
1825 * We use the MLDv2 state machine at group level. The MLd module
1826 * however makes the decision as to which MLD protocol version to speak.
1827 * A state change *from* INCLUDE {} always means an initial join.
1828 * A state change *to* INCLUDE {} always means a final leave.
1829 *
1830 * If delay is non-zero, and the state change is an initial multicast
1831 * join, the state change report will be delayed by 'delay' ticks
1832 * in units of MLD_FASTHZ if MLDv1 is active on the link; otherwise
1833 * the initial MLDv2 state change report will be delayed by whichever
1834 * is sooner, a pending state-change timer or delay itself.
1835 *
1836 * VIMAGE: curvnet should have been set by caller, as this routine
1837 * is called from the socket option handlers.
1838 */
1839 int
mld_change_state(struct in6_multi * inm,const int delay)1840 mld_change_state(struct in6_multi *inm, const int delay)
1841 {
1842 struct mld_ifsoftc *mli;
1843 struct ifnet *ifp;
1844 int error;
1845
1846 IN6_MULTI_LIST_LOCK_ASSERT();
1847
1848 error = 0;
1849
1850 /*
1851 * Check if the in6_multi has already been disconnected.
1852 */
1853 if (inm->in6m_ifp == NULL) {
1854 CTR1(KTR_MLD, "%s: inm is disconnected", __func__);
1855 return (0);
1856 }
1857
1858 /*
1859 * Try to detect if the upper layer just asked us to change state
1860 * for an interface which has now gone away.
1861 */
1862 KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
1863 ifp = inm->in6m_ifma->ifma_ifp;
1864 if (ifp == NULL)
1865 return (0);
1866 /*
1867 * Sanity check that netinet6's notion of ifp is the
1868 * same as net's.
1869 */
1870 KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
1871
1872 MLD_LOCK();
1873 mli = MLD_IFINFO(ifp);
1874 KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
1875
1876 /*
1877 * If we detect a state transition to or from MCAST_UNDEFINED
1878 * for this group, then we are starting or finishing an MLD
1879 * life cycle for this group.
1880 */
1881 if (inm->in6m_st[1].iss_fmode != inm->in6m_st[0].iss_fmode) {
1882 CTR3(KTR_MLD, "%s: inm transition %d -> %d", __func__,
1883 inm->in6m_st[0].iss_fmode, inm->in6m_st[1].iss_fmode);
1884 if (inm->in6m_st[0].iss_fmode == MCAST_UNDEFINED) {
1885 CTR1(KTR_MLD, "%s: initial join", __func__);
1886 error = mld_initial_join(inm, mli, delay);
1887 goto out_locked;
1888 } else if (inm->in6m_st[1].iss_fmode == MCAST_UNDEFINED) {
1889 CTR1(KTR_MLD, "%s: final leave", __func__);
1890 mld_final_leave(inm, mli);
1891 goto out_locked;
1892 }
1893 } else {
1894 CTR1(KTR_MLD, "%s: filter set change", __func__);
1895 }
1896
1897 error = mld_handle_state_change(inm, mli);
1898
1899 out_locked:
1900 MLD_UNLOCK();
1901 return (error);
1902 }
1903
1904 /*
1905 * Perform the initial join for an MLD group.
1906 *
1907 * When joining a group:
1908 * If the group should have its MLD traffic suppressed, do nothing.
1909 * MLDv1 starts sending MLDv1 host membership reports.
1910 * MLDv2 will schedule an MLDv2 state-change report containing the
1911 * initial state of the membership.
1912 *
1913 * If the delay argument is non-zero, then we must delay sending the
1914 * initial state change for delay ticks (in units of MLD_FASTHZ).
1915 */
1916 static int
mld_initial_join(struct in6_multi * inm,struct mld_ifsoftc * mli,const int delay)1917 mld_initial_join(struct in6_multi *inm, struct mld_ifsoftc *mli,
1918 const int delay)
1919 {
1920 struct epoch_tracker et;
1921 struct ifnet *ifp;
1922 struct mbufq *mq;
1923 int error, retval, syncstates;
1924 int odelay;
1925 #ifdef KTR
1926 char ip6tbuf[INET6_ADDRSTRLEN];
1927 #endif
1928
1929 CTR4(KTR_MLD, "%s: initial join %s on ifp %p(%s)",
1930 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1931 inm->in6m_ifp, if_name(inm->in6m_ifp));
1932
1933 error = 0;
1934 syncstates = 1;
1935
1936 ifp = inm->in6m_ifp;
1937
1938 IN6_MULTI_LIST_LOCK_ASSERT();
1939 MLD_LOCK_ASSERT();
1940
1941 KASSERT(mli && mli->mli_ifp == ifp, ("%s: inconsistent ifp", __func__));
1942
1943 /*
1944 * Groups joined on loopback or marked as 'not reported',
1945 * enter the MLD_SILENT_MEMBER state and
1946 * are never reported in any protocol exchanges.
1947 * All other groups enter the appropriate state machine
1948 * for the version in use on this link.
1949 * A link marked as MLIF_SILENT causes MLD to be completely
1950 * disabled for the link.
1951 */
1952 if ((ifp->if_flags & IFF_LOOPBACK) ||
1953 (mli->mli_flags & MLIF_SILENT) ||
1954 !mld_is_addr_reported(&inm->in6m_addr)) {
1955 CTR1(KTR_MLD,
1956 "%s: not kicking state machine for silent group", __func__);
1957 inm->in6m_state = MLD_SILENT_MEMBER;
1958 inm->in6m_timer = 0;
1959 } else {
1960 /*
1961 * Deal with overlapping in_multi lifecycle.
1962 * If this group was LEAVING, then make sure
1963 * we drop the reference we picked up to keep the
1964 * group around for the final INCLUDE {} enqueue.
1965 */
1966 if (mli->mli_version == MLD_VERSION_2 &&
1967 inm->in6m_state == MLD_LEAVING_MEMBER) {
1968 inm->in6m_refcount--;
1969 MPASS(inm->in6m_refcount > 0);
1970 }
1971 inm->in6m_state = MLD_REPORTING_MEMBER;
1972
1973 switch (mli->mli_version) {
1974 case MLD_VERSION_1:
1975 /*
1976 * If a delay was provided, only use it if
1977 * it is greater than the delay normally
1978 * used for an MLDv1 state change report,
1979 * and delay sending the initial MLDv1 report
1980 * by not transitioning to the IDLE state.
1981 */
1982 odelay = MLD_RANDOM_DELAY(MLD_V1_MAX_RI * MLD_FASTHZ);
1983 if (delay) {
1984 inm->in6m_timer = max(delay, odelay);
1985 V_current_state_timers_running6 = 1;
1986 } else {
1987 inm->in6m_state = MLD_IDLE_MEMBER;
1988 NET_EPOCH_ENTER(et);
1989 error = mld_v1_transmit_report(inm,
1990 MLD_LISTENER_REPORT);
1991 NET_EPOCH_EXIT(et);
1992 if (error == 0) {
1993 inm->in6m_timer = odelay;
1994 V_current_state_timers_running6 = 1;
1995 }
1996 }
1997 break;
1998
1999 case MLD_VERSION_2:
2000 /*
2001 * Defer update of T0 to T1, until the first copy
2002 * of the state change has been transmitted.
2003 */
2004 syncstates = 0;
2005
2006 /*
2007 * Immediately enqueue a State-Change Report for
2008 * this interface, freeing any previous reports.
2009 * Don't kick the timers if there is nothing to do,
2010 * or if an error occurred.
2011 */
2012 mq = &inm->in6m_scq;
2013 mbufq_drain(mq);
2014 retval = mld_v2_enqueue_group_record(mq, inm, 1,
2015 0, 0, (mli->mli_flags & MLIF_USEALLOW));
2016 CTR2(KTR_MLD, "%s: enqueue record = %d",
2017 __func__, retval);
2018 if (retval <= 0) {
2019 error = retval * -1;
2020 break;
2021 }
2022
2023 /*
2024 * Schedule transmission of pending state-change
2025 * report up to RV times for this link. The timer
2026 * will fire at the next mld_fasttimo (~200ms),
2027 * giving us an opportunity to merge the reports.
2028 *
2029 * If a delay was provided to this function, only
2030 * use this delay if sooner than the existing one.
2031 */
2032 KASSERT(mli->mli_rv > 1,
2033 ("%s: invalid robustness %d", __func__,
2034 mli->mli_rv));
2035 inm->in6m_scrv = mli->mli_rv;
2036 if (delay) {
2037 if (inm->in6m_sctimer > 1) {
2038 inm->in6m_sctimer =
2039 min(inm->in6m_sctimer, delay);
2040 } else
2041 inm->in6m_sctimer = delay;
2042 } else
2043 inm->in6m_sctimer = 1;
2044 V_state_change_timers_running6 = 1;
2045
2046 error = 0;
2047 break;
2048 }
2049 }
2050
2051 /*
2052 * Only update the T0 state if state change is atomic,
2053 * i.e. we don't need to wait for a timer to fire before we
2054 * can consider the state change to have been communicated.
2055 */
2056 if (syncstates) {
2057 in6m_commit(inm);
2058 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2059 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2060 if_name(inm->in6m_ifp));
2061 }
2062
2063 return (error);
2064 }
2065
2066 /*
2067 * Issue an intermediate state change during the life-cycle.
2068 */
2069 static int
mld_handle_state_change(struct in6_multi * inm,struct mld_ifsoftc * mli)2070 mld_handle_state_change(struct in6_multi *inm, struct mld_ifsoftc *mli)
2071 {
2072 struct ifnet *ifp;
2073 int retval;
2074 #ifdef KTR
2075 char ip6tbuf[INET6_ADDRSTRLEN];
2076 #endif
2077
2078 CTR4(KTR_MLD, "%s: state change for %s on ifp %p(%s)",
2079 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2080 inm->in6m_ifp, if_name(inm->in6m_ifp));
2081
2082 ifp = inm->in6m_ifp;
2083
2084 IN6_MULTI_LIST_LOCK_ASSERT();
2085 MLD_LOCK_ASSERT();
2086
2087 KASSERT(mli && mli->mli_ifp == ifp,
2088 ("%s: inconsistent ifp", __func__));
2089
2090 if ((ifp->if_flags & IFF_LOOPBACK) ||
2091 (mli->mli_flags & MLIF_SILENT) ||
2092 !mld_is_addr_reported(&inm->in6m_addr) ||
2093 (mli->mli_version != MLD_VERSION_2)) {
2094 if (!mld_is_addr_reported(&inm->in6m_addr)) {
2095 CTR1(KTR_MLD,
2096 "%s: not kicking state machine for silent group", __func__);
2097 }
2098 CTR1(KTR_MLD, "%s: nothing to do", __func__);
2099 in6m_commit(inm);
2100 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2101 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2102 if_name(inm->in6m_ifp));
2103 return (0);
2104 }
2105
2106 mbufq_drain(&inm->in6m_scq);
2107
2108 retval = mld_v2_enqueue_group_record(&inm->in6m_scq, inm, 1, 0, 0,
2109 (mli->mli_flags & MLIF_USEALLOW));
2110 CTR2(KTR_MLD, "%s: enqueue record = %d", __func__, retval);
2111 if (retval <= 0)
2112 return (-retval);
2113
2114 /*
2115 * If record(s) were enqueued, start the state-change
2116 * report timer for this group.
2117 */
2118 inm->in6m_scrv = mli->mli_rv;
2119 inm->in6m_sctimer = 1;
2120 V_state_change_timers_running6 = 1;
2121
2122 return (0);
2123 }
2124
2125 /*
2126 * Perform the final leave for a multicast address.
2127 *
2128 * When leaving a group:
2129 * MLDv1 sends a DONE message, if and only if we are the reporter.
2130 * MLDv2 enqueues a state-change report containing a transition
2131 * to INCLUDE {} for immediate transmission.
2132 */
2133 static void
mld_final_leave(struct in6_multi * inm,struct mld_ifsoftc * mli)2134 mld_final_leave(struct in6_multi *inm, struct mld_ifsoftc *mli)
2135 {
2136 struct epoch_tracker et;
2137 #ifdef KTR
2138 char ip6tbuf[INET6_ADDRSTRLEN];
2139 #endif
2140
2141 CTR4(KTR_MLD, "%s: final leave %s on ifp %p(%s)",
2142 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2143 inm->in6m_ifp, if_name(inm->in6m_ifp));
2144
2145 IN6_MULTI_LIST_LOCK_ASSERT();
2146 MLD_LOCK_ASSERT();
2147
2148 switch (inm->in6m_state) {
2149 case MLD_NOT_MEMBER:
2150 case MLD_SILENT_MEMBER:
2151 case MLD_LEAVING_MEMBER:
2152 /* Already leaving or left; do nothing. */
2153 CTR1(KTR_MLD,
2154 "%s: not kicking state machine for silent group", __func__);
2155 break;
2156 case MLD_REPORTING_MEMBER:
2157 case MLD_IDLE_MEMBER:
2158 case MLD_G_QUERY_PENDING_MEMBER:
2159 case MLD_SG_QUERY_PENDING_MEMBER:
2160 if (mli->mli_version == MLD_VERSION_1) {
2161 #ifdef INVARIANTS
2162 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
2163 inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER)
2164 panic("%s: MLDv2 state reached, not MLDv2 mode",
2165 __func__);
2166 #endif
2167 NET_EPOCH_ENTER(et);
2168 mld_v1_transmit_report(inm, MLD_LISTENER_DONE);
2169 NET_EPOCH_EXIT(et);
2170 inm->in6m_state = MLD_NOT_MEMBER;
2171 V_current_state_timers_running6 = 1;
2172 } else if (mli->mli_version == MLD_VERSION_2) {
2173 /*
2174 * Stop group timer and all pending reports.
2175 * Immediately enqueue a state-change report
2176 * TO_IN {} to be sent on the next fast timeout,
2177 * giving us an opportunity to merge reports.
2178 */
2179 mbufq_drain(&inm->in6m_scq);
2180 inm->in6m_timer = 0;
2181 inm->in6m_scrv = mli->mli_rv;
2182 CTR4(KTR_MLD, "%s: Leaving %s/%s with %d "
2183 "pending retransmissions.", __func__,
2184 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2185 if_name(inm->in6m_ifp), inm->in6m_scrv);
2186 if (inm->in6m_scrv == 0) {
2187 inm->in6m_state = MLD_NOT_MEMBER;
2188 inm->in6m_sctimer = 0;
2189 } else {
2190 int retval __diagused;
2191
2192 in6m_acquire_locked(inm);
2193
2194 retval = mld_v2_enqueue_group_record(
2195 &inm->in6m_scq, inm, 1, 0, 0,
2196 (mli->mli_flags & MLIF_USEALLOW));
2197 KASSERT(retval != 0,
2198 ("%s: enqueue record = %d", __func__,
2199 retval));
2200
2201 inm->in6m_state = MLD_LEAVING_MEMBER;
2202 inm->in6m_sctimer = 1;
2203 V_state_change_timers_running6 = 1;
2204 }
2205 break;
2206 }
2207 break;
2208 case MLD_LAZY_MEMBER:
2209 case MLD_SLEEPING_MEMBER:
2210 case MLD_AWAKENING_MEMBER:
2211 /* Our reports are suppressed; do nothing. */
2212 break;
2213 }
2214
2215 in6m_commit(inm);
2216 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2217 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2218 if_name(inm->in6m_ifp));
2219 inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
2220 CTR3(KTR_MLD, "%s: T1 now MCAST_UNDEFINED for %p/%s",
2221 __func__, &inm->in6m_addr, if_name(inm->in6m_ifp));
2222 }
2223
2224 /*
2225 * Enqueue an MLDv2 group record to the given output queue.
2226 *
2227 * If is_state_change is zero, a current-state record is appended.
2228 * If is_state_change is non-zero, a state-change report is appended.
2229 *
2230 * If is_group_query is non-zero, an mbuf packet chain is allocated.
2231 * If is_group_query is zero, and if there is a packet with free space
2232 * at the tail of the queue, it will be appended to providing there
2233 * is enough free space.
2234 * Otherwise a new mbuf packet chain is allocated.
2235 *
2236 * If is_source_query is non-zero, each source is checked to see if
2237 * it was recorded for a Group-Source query, and will be omitted if
2238 * it is not both in-mode and recorded.
2239 *
2240 * If use_block_allow is non-zero, state change reports for initial join
2241 * and final leave, on an inclusive mode group with a source list, will be
2242 * rewritten to use the ALLOW_NEW and BLOCK_OLD record types, respectively.
2243 *
2244 * The function will attempt to allocate leading space in the packet
2245 * for the IPv6+ICMP headers to be prepended without fragmenting the chain.
2246 *
2247 * If successful the size of all data appended to the queue is returned,
2248 * otherwise an error code less than zero is returned, or zero if
2249 * no record(s) were appended.
2250 */
2251 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)2252 mld_v2_enqueue_group_record(struct mbufq *mq, struct in6_multi *inm,
2253 const int is_state_change, const int is_group_query,
2254 const int is_source_query, const int use_block_allow)
2255 {
2256 struct mldv2_record mr;
2257 struct mldv2_record *pmr;
2258 struct ifnet *ifp;
2259 struct ip6_msource *ims, *nims;
2260 struct mbuf *m0, *m, *md;
2261 int is_filter_list_change;
2262 int minrec0len, m0srcs, msrcs, nbytes, off;
2263 int record_has_sources;
2264 int now;
2265 int type;
2266 uint8_t mode;
2267 #ifdef KTR
2268 char ip6tbuf[INET6_ADDRSTRLEN];
2269 #endif
2270
2271 IN6_MULTI_LIST_LOCK_ASSERT();
2272
2273 ifp = inm->in6m_ifp;
2274 is_filter_list_change = 0;
2275 m = NULL;
2276 m0 = NULL;
2277 m0srcs = 0;
2278 msrcs = 0;
2279 nbytes = 0;
2280 nims = NULL;
2281 record_has_sources = 1;
2282 pmr = NULL;
2283 type = MLD_DO_NOTHING;
2284 mode = inm->in6m_st[1].iss_fmode;
2285
2286 /*
2287 * If we did not transition out of ASM mode during t0->t1,
2288 * and there are no source nodes to process, we can skip
2289 * the generation of source records.
2290 */
2291 if (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0 &&
2292 inm->in6m_nsrc == 0)
2293 record_has_sources = 0;
2294
2295 if (is_state_change) {
2296 /*
2297 * Queue a state change record.
2298 * If the mode did not change, and there are non-ASM
2299 * listeners or source filters present,
2300 * we potentially need to issue two records for the group.
2301 * If there are ASM listeners, and there was no filter
2302 * mode transition of any kind, do nothing.
2303 *
2304 * If we are transitioning to MCAST_UNDEFINED, we need
2305 * not send any sources. A transition to/from this state is
2306 * considered inclusive with some special treatment.
2307 *
2308 * If we are rewriting initial joins/leaves to use
2309 * ALLOW/BLOCK, and the group's membership is inclusive,
2310 * we need to send sources in all cases.
2311 */
2312 if (mode != inm->in6m_st[0].iss_fmode) {
2313 if (mode == MCAST_EXCLUDE) {
2314 CTR1(KTR_MLD, "%s: change to EXCLUDE",
2315 __func__);
2316 type = MLD_CHANGE_TO_EXCLUDE_MODE;
2317 } else {
2318 CTR1(KTR_MLD, "%s: change to INCLUDE",
2319 __func__);
2320 if (use_block_allow) {
2321 /*
2322 * XXX
2323 * Here we're interested in state
2324 * edges either direction between
2325 * MCAST_UNDEFINED and MCAST_INCLUDE.
2326 * Perhaps we should just check
2327 * the group state, rather than
2328 * the filter mode.
2329 */
2330 if (mode == MCAST_UNDEFINED) {
2331 type = MLD_BLOCK_OLD_SOURCES;
2332 } else {
2333 type = MLD_ALLOW_NEW_SOURCES;
2334 }
2335 } else {
2336 type = MLD_CHANGE_TO_INCLUDE_MODE;
2337 if (mode == MCAST_UNDEFINED)
2338 record_has_sources = 0;
2339 }
2340 }
2341 } else {
2342 if (record_has_sources) {
2343 is_filter_list_change = 1;
2344 } else {
2345 type = MLD_DO_NOTHING;
2346 }
2347 }
2348 } else {
2349 /*
2350 * Queue a current state record.
2351 */
2352 if (mode == MCAST_EXCLUDE) {
2353 type = MLD_MODE_IS_EXCLUDE;
2354 } else if (mode == MCAST_INCLUDE) {
2355 type = MLD_MODE_IS_INCLUDE;
2356 KASSERT(inm->in6m_st[1].iss_asm == 0,
2357 ("%s: inm %p is INCLUDE but ASM count is %d",
2358 __func__, inm, inm->in6m_st[1].iss_asm));
2359 }
2360 }
2361
2362 /*
2363 * Generate the filter list changes using a separate function.
2364 */
2365 if (is_filter_list_change)
2366 return (mld_v2_enqueue_filter_change(mq, inm));
2367
2368 if (type == MLD_DO_NOTHING) {
2369 CTR3(KTR_MLD, "%s: nothing to do for %s/%s",
2370 __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2371 if_name(inm->in6m_ifp));
2372 return (0);
2373 }
2374
2375 /*
2376 * If any sources are present, we must be able to fit at least
2377 * one in the trailing space of the tail packet's mbuf,
2378 * ideally more.
2379 */
2380 minrec0len = sizeof(struct mldv2_record);
2381 if (record_has_sources)
2382 minrec0len += sizeof(struct in6_addr);
2383
2384 CTR4(KTR_MLD, "%s: queueing %s for %s/%s", __func__,
2385 mld_rec_type_to_str(type),
2386 ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2387 if_name(inm->in6m_ifp));
2388
2389 /*
2390 * Check if we have a packet in the tail of the queue for this
2391 * group into which the first group record for this group will fit.
2392 * Otherwise allocate a new packet.
2393 * Always allocate leading space for IP6+RA+ICMPV6+REPORT.
2394 * Note: Group records for G/GSR query responses MUST be sent
2395 * in their own packet.
2396 */
2397 m0 = mbufq_last(mq);
2398 if (!is_group_query &&
2399 m0 != NULL &&
2400 (m0->m_pkthdr.vt_nrecs + 1 <= MLD_V2_REPORT_MAXRECS) &&
2401 (m0->m_pkthdr.len + minrec0len) <
2402 (ifp->if_mtu - MLD_MTUSPACE)) {
2403 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2404 sizeof(struct mldv2_record)) /
2405 sizeof(struct in6_addr);
2406 m = m0;
2407 CTR1(KTR_MLD, "%s: use existing packet", __func__);
2408 } else {
2409 if (mbufq_full(mq)) {
2410 CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2411 return (-ENOMEM);
2412 }
2413 m = NULL;
2414 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2415 sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2416 if (!is_state_change && !is_group_query)
2417 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2418 if (m == NULL)
2419 m = m_gethdr(M_NOWAIT, MT_DATA);
2420 if (m == NULL)
2421 return (-ENOMEM);
2422
2423 mld_save_context(m, ifp);
2424
2425 CTR1(KTR_MLD, "%s: allocated first packet", __func__);
2426 }
2427
2428 /*
2429 * Append group record.
2430 * If we have sources, we don't know how many yet.
2431 */
2432 mr.mr_type = type;
2433 mr.mr_datalen = 0;
2434 mr.mr_numsrc = 0;
2435 mr.mr_addr = inm->in6m_addr;
2436 in6_clearscope(&mr.mr_addr);
2437 if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2438 if (m != m0)
2439 m_freem(m);
2440 CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2441 return (-ENOMEM);
2442 }
2443 nbytes += sizeof(struct mldv2_record);
2444
2445 /*
2446 * Append as many sources as will fit in the first packet.
2447 * If we are appending to a new packet, the chain allocation
2448 * may potentially use clusters; use m_getptr() in this case.
2449 * If we are appending to an existing packet, we need to obtain
2450 * a pointer to the group record after m_append(), in case a new
2451 * mbuf was allocated.
2452 *
2453 * Only append sources which are in-mode at t1. If we are
2454 * transitioning to MCAST_UNDEFINED state on the group, and
2455 * use_block_allow is zero, do not include source entries.
2456 * Otherwise, we need to include this source in the report.
2457 *
2458 * Only report recorded sources in our filter set when responding
2459 * to a group-source query.
2460 */
2461 if (record_has_sources) {
2462 if (m == m0) {
2463 md = m_last(m);
2464 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2465 md->m_len - nbytes);
2466 } else {
2467 md = m_getptr(m, 0, &off);
2468 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2469 off);
2470 }
2471 msrcs = 0;
2472 RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs,
2473 nims) {
2474 CTR2(KTR_MLD, "%s: visit node %s", __func__,
2475 ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2476 now = im6s_get_mode(inm, ims, 1);
2477 CTR2(KTR_MLD, "%s: node is %d", __func__, now);
2478 if ((now != mode) ||
2479 (now == mode &&
2480 (!use_block_allow && mode == MCAST_UNDEFINED))) {
2481 CTR1(KTR_MLD, "%s: skip node", __func__);
2482 continue;
2483 }
2484 if (is_source_query && ims->im6s_stp == 0) {
2485 CTR1(KTR_MLD, "%s: skip unrecorded node",
2486 __func__);
2487 continue;
2488 }
2489 CTR1(KTR_MLD, "%s: append node", __func__);
2490 if (!m_append(m, sizeof(struct in6_addr),
2491 (void *)&ims->im6s_addr)) {
2492 if (m != m0)
2493 m_freem(m);
2494 CTR1(KTR_MLD, "%s: m_append() failed.",
2495 __func__);
2496 return (-ENOMEM);
2497 }
2498 nbytes += sizeof(struct in6_addr);
2499 ++msrcs;
2500 if (msrcs == m0srcs)
2501 break;
2502 }
2503 CTR2(KTR_MLD, "%s: msrcs is %d this packet", __func__,
2504 msrcs);
2505 pmr->mr_numsrc = htons(msrcs);
2506 nbytes += (msrcs * sizeof(struct in6_addr));
2507 }
2508
2509 if (is_source_query && msrcs == 0) {
2510 CTR1(KTR_MLD, "%s: no recorded sources to report", __func__);
2511 if (m != m0)
2512 m_freem(m);
2513 return (0);
2514 }
2515
2516 /*
2517 * We are good to go with first packet.
2518 */
2519 if (m != m0) {
2520 CTR1(KTR_MLD, "%s: enqueueing first packet", __func__);
2521 m->m_pkthdr.vt_nrecs = 1;
2522 mbufq_enqueue(mq, m);
2523 } else
2524 m->m_pkthdr.vt_nrecs++;
2525
2526 /*
2527 * No further work needed if no source list in packet(s).
2528 */
2529 if (!record_has_sources)
2530 return (nbytes);
2531
2532 /*
2533 * Whilst sources remain to be announced, we need to allocate
2534 * a new packet and fill out as many sources as will fit.
2535 * Always try for a cluster first.
2536 */
2537 while (nims != NULL) {
2538 if (mbufq_full(mq)) {
2539 CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2540 return (-ENOMEM);
2541 }
2542 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2543 if (m == NULL)
2544 m = m_gethdr(M_NOWAIT, MT_DATA);
2545 if (m == NULL)
2546 return (-ENOMEM);
2547 mld_save_context(m, ifp);
2548 md = m_getptr(m, 0, &off);
2549 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) + off);
2550 CTR1(KTR_MLD, "%s: allocated next packet", __func__);
2551
2552 if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2553 if (m != m0)
2554 m_freem(m);
2555 CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2556 return (-ENOMEM);
2557 }
2558 m->m_pkthdr.vt_nrecs = 1;
2559 nbytes += sizeof(struct mldv2_record);
2560
2561 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2562 sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2563
2564 msrcs = 0;
2565 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2566 CTR2(KTR_MLD, "%s: visit node %s",
2567 __func__, ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2568 now = im6s_get_mode(inm, ims, 1);
2569 if ((now != mode) ||
2570 (now == mode &&
2571 (!use_block_allow && mode == MCAST_UNDEFINED))) {
2572 CTR1(KTR_MLD, "%s: skip node", __func__);
2573 continue;
2574 }
2575 if (is_source_query && ims->im6s_stp == 0) {
2576 CTR1(KTR_MLD, "%s: skip unrecorded node",
2577 __func__);
2578 continue;
2579 }
2580 CTR1(KTR_MLD, "%s: append node", __func__);
2581 if (!m_append(m, sizeof(struct in6_addr),
2582 (void *)&ims->im6s_addr)) {
2583 if (m != m0)
2584 m_freem(m);
2585 CTR1(KTR_MLD, "%s: m_append() failed.",
2586 __func__);
2587 return (-ENOMEM);
2588 }
2589 ++msrcs;
2590 if (msrcs == m0srcs)
2591 break;
2592 }
2593 pmr->mr_numsrc = htons(msrcs);
2594 nbytes += (msrcs * sizeof(struct in6_addr));
2595
2596 CTR1(KTR_MLD, "%s: enqueueing next packet", __func__);
2597 mbufq_enqueue(mq, m);
2598 }
2599
2600 return (nbytes);
2601 }
2602
2603 /*
2604 * Type used to mark record pass completion.
2605 * We exploit the fact we can cast to this easily from the
2606 * current filter modes on each ip_msource node.
2607 */
2608 typedef enum {
2609 REC_NONE = 0x00, /* MCAST_UNDEFINED */
2610 REC_ALLOW = 0x01, /* MCAST_INCLUDE */
2611 REC_BLOCK = 0x02, /* MCAST_EXCLUDE */
2612 REC_FULL = REC_ALLOW | REC_BLOCK
2613 } rectype_t;
2614
2615 /*
2616 * Enqueue an MLDv2 filter list change to the given output queue.
2617 *
2618 * Source list filter state is held in an RB-tree. When the filter list
2619 * for a group is changed without changing its mode, we need to compute
2620 * the deltas between T0 and T1 for each source in the filter set,
2621 * and enqueue the appropriate ALLOW_NEW/BLOCK_OLD records.
2622 *
2623 * As we may potentially queue two record types, and the entire R-B tree
2624 * needs to be walked at once, we break this out into its own function
2625 * so we can generate a tightly packed queue of packets.
2626 *
2627 * XXX This could be written to only use one tree walk, although that makes
2628 * serializing into the mbuf chains a bit harder. For now we do two walks
2629 * which makes things easier on us, and it may or may not be harder on
2630 * the L2 cache.
2631 *
2632 * If successful the size of all data appended to the queue is returned,
2633 * otherwise an error code less than zero is returned, or zero if
2634 * no record(s) were appended.
2635 */
2636 static int
mld_v2_enqueue_filter_change(struct mbufq * mq,struct in6_multi * inm)2637 mld_v2_enqueue_filter_change(struct mbufq *mq, struct in6_multi *inm)
2638 {
2639 static const int MINRECLEN =
2640 sizeof(struct mldv2_record) + sizeof(struct in6_addr);
2641 struct ifnet *ifp;
2642 struct mldv2_record mr;
2643 struct mldv2_record *pmr;
2644 struct ip6_msource *ims, *nims;
2645 struct mbuf *m, *m0, *md;
2646 int m0srcs, nbytes, npbytes, off, rsrcs, schanged;
2647 uint8_t mode, now, then;
2648 rectype_t crt, drt, nrt;
2649 #ifdef KTR
2650 int nallow, nblock;
2651 char ip6tbuf[INET6_ADDRSTRLEN];
2652 #endif
2653
2654 IN6_MULTI_LIST_LOCK_ASSERT();
2655
2656 if (inm->in6m_nsrc == 0 ||
2657 (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0))
2658 return (0);
2659
2660 ifp = inm->in6m_ifp; /* interface */
2661 mode = inm->in6m_st[1].iss_fmode; /* filter mode at t1 */
2662 crt = REC_NONE; /* current group record type */
2663 drt = REC_NONE; /* mask of completed group record types */
2664 nrt = REC_NONE; /* record type for current node */
2665 m0srcs = 0; /* # source which will fit in current mbuf chain */
2666 npbytes = 0; /* # of bytes appended this packet */
2667 nbytes = 0; /* # of bytes appended to group's state-change queue */
2668 rsrcs = 0; /* # sources encoded in current record */
2669 schanged = 0; /* # nodes encoded in overall filter change */
2670 #ifdef KTR
2671 nallow = 0; /* # of source entries in ALLOW_NEW */
2672 nblock = 0; /* # of source entries in BLOCK_OLD */
2673 #endif
2674 nims = NULL; /* next tree node pointer */
2675
2676 /*
2677 * For each possible filter record mode.
2678 * The first kind of source we encounter tells us which
2679 * is the first kind of record we start appending.
2680 * If a node transitioned to UNDEFINED at t1, its mode is treated
2681 * as the inverse of the group's filter mode.
2682 */
2683 while (drt != REC_FULL) {
2684 do {
2685 m0 = mbufq_last(mq);
2686 if (m0 != NULL &&
2687 (m0->m_pkthdr.vt_nrecs + 1 <=
2688 MLD_V2_REPORT_MAXRECS) &&
2689 (m0->m_pkthdr.len + MINRECLEN) <
2690 (ifp->if_mtu - MLD_MTUSPACE)) {
2691 m = m0;
2692 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2693 sizeof(struct mldv2_record)) /
2694 sizeof(struct in6_addr);
2695 CTR1(KTR_MLD,
2696 "%s: use previous packet", __func__);
2697 } else {
2698 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2699 if (m == NULL)
2700 m = m_gethdr(M_NOWAIT, MT_DATA);
2701 if (m == NULL) {
2702 CTR1(KTR_MLD,
2703 "%s: m_get*() failed", __func__);
2704 return (-ENOMEM);
2705 }
2706 m->m_pkthdr.vt_nrecs = 0;
2707 mld_save_context(m, ifp);
2708 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2709 sizeof(struct mldv2_record)) /
2710 sizeof(struct in6_addr);
2711 npbytes = 0;
2712 CTR1(KTR_MLD,
2713 "%s: allocated new packet", __func__);
2714 }
2715 /*
2716 * Append the MLD group record header to the
2717 * current packet's data area.
2718 * Recalculate pointer to free space for next
2719 * group record, in case m_append() allocated
2720 * a new mbuf or cluster.
2721 */
2722 memset(&mr, 0, sizeof(mr));
2723 mr.mr_addr = inm->in6m_addr;
2724 in6_clearscope(&mr.mr_addr);
2725 if (!m_append(m, sizeof(mr), (void *)&mr)) {
2726 if (m != m0)
2727 m_freem(m);
2728 CTR1(KTR_MLD,
2729 "%s: m_append() failed", __func__);
2730 return (-ENOMEM);
2731 }
2732 npbytes += sizeof(struct mldv2_record);
2733 if (m != m0) {
2734 /* new packet; offset in chain */
2735 md = m_getptr(m, npbytes -
2736 sizeof(struct mldv2_record), &off);
2737 pmr = (struct mldv2_record *)(mtod(md,
2738 uint8_t *) + off);
2739 } else {
2740 /* current packet; offset from last append */
2741 md = m_last(m);
2742 pmr = (struct mldv2_record *)(mtod(md,
2743 uint8_t *) + md->m_len -
2744 sizeof(struct mldv2_record));
2745 }
2746 /*
2747 * Begin walking the tree for this record type
2748 * pass, or continue from where we left off
2749 * previously if we had to allocate a new packet.
2750 * Only report deltas in-mode at t1.
2751 * We need not report included sources as allowed
2752 * if we are in inclusive mode on the group,
2753 * however the converse is not true.
2754 */
2755 rsrcs = 0;
2756 if (nims == NULL) {
2757 nims = RB_MIN(ip6_msource_tree,
2758 &inm->in6m_srcs);
2759 }
2760 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2761 CTR2(KTR_MLD, "%s: visit node %s", __func__,
2762 ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2763 now = im6s_get_mode(inm, ims, 1);
2764 then = im6s_get_mode(inm, ims, 0);
2765 CTR3(KTR_MLD, "%s: mode: t0 %d, t1 %d",
2766 __func__, then, now);
2767 if (now == then) {
2768 CTR1(KTR_MLD,
2769 "%s: skip unchanged", __func__);
2770 continue;
2771 }
2772 if (mode == MCAST_EXCLUDE &&
2773 now == MCAST_INCLUDE) {
2774 CTR1(KTR_MLD,
2775 "%s: skip IN src on EX group",
2776 __func__);
2777 continue;
2778 }
2779 nrt = (rectype_t)now;
2780 if (nrt == REC_NONE)
2781 nrt = (rectype_t)(~mode & REC_FULL);
2782 if (schanged++ == 0) {
2783 crt = nrt;
2784 } else if (crt != nrt)
2785 continue;
2786 if (!m_append(m, sizeof(struct in6_addr),
2787 (void *)&ims->im6s_addr)) {
2788 if (m != m0)
2789 m_freem(m);
2790 CTR1(KTR_MLD,
2791 "%s: m_append() failed", __func__);
2792 return (-ENOMEM);
2793 }
2794 #ifdef KTR
2795 nallow += !!(crt == REC_ALLOW);
2796 nblock += !!(crt == REC_BLOCK);
2797 #endif
2798 if (++rsrcs == m0srcs)
2799 break;
2800 }
2801 /*
2802 * If we did not append any tree nodes on this
2803 * pass, back out of allocations.
2804 */
2805 if (rsrcs == 0) {
2806 npbytes -= sizeof(struct mldv2_record);
2807 if (m != m0) {
2808 CTR1(KTR_MLD,
2809 "%s: m_free(m)", __func__);
2810 m_freem(m);
2811 } else {
2812 CTR1(KTR_MLD,
2813 "%s: m_adj(m, -mr)", __func__);
2814 m_adj(m, -((int)sizeof(
2815 struct mldv2_record)));
2816 }
2817 continue;
2818 }
2819 npbytes += (rsrcs * sizeof(struct in6_addr));
2820 if (crt == REC_ALLOW)
2821 pmr->mr_type = MLD_ALLOW_NEW_SOURCES;
2822 else if (crt == REC_BLOCK)
2823 pmr->mr_type = MLD_BLOCK_OLD_SOURCES;
2824 pmr->mr_numsrc = htons(rsrcs);
2825 /*
2826 * Count the new group record, and enqueue this
2827 * packet if it wasn't already queued.
2828 */
2829 m->m_pkthdr.vt_nrecs++;
2830 if (m != m0)
2831 mbufq_enqueue(mq, m);
2832 nbytes += npbytes;
2833 } while (nims != NULL);
2834 drt |= crt;
2835 crt = (~crt & REC_FULL);
2836 }
2837
2838 CTR3(KTR_MLD, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
2839 nallow, nblock);
2840
2841 return (nbytes);
2842 }
2843
2844 static int
mld_v2_merge_state_changes(struct in6_multi * inm,struct mbufq * scq)2845 mld_v2_merge_state_changes(struct in6_multi *inm, struct mbufq *scq)
2846 {
2847 struct mbufq *gq;
2848 struct mbuf *m; /* pending state-change */
2849 struct mbuf *m0; /* copy of pending state-change */
2850 struct mbuf *mt; /* last state-change in packet */
2851 int docopy, domerge;
2852 u_int recslen;
2853
2854 docopy = 0;
2855 domerge = 0;
2856 recslen = 0;
2857
2858 IN6_MULTI_LIST_LOCK_ASSERT();
2859 MLD_LOCK_ASSERT();
2860
2861 /*
2862 * If there are further pending retransmissions, make a writable
2863 * copy of each queued state-change message before merging.
2864 */
2865 if (inm->in6m_scrv > 0)
2866 docopy = 1;
2867
2868 gq = &inm->in6m_scq;
2869 #ifdef KTR
2870 if (mbufq_first(gq) == NULL) {
2871 CTR2(KTR_MLD, "%s: WARNING: queue for inm %p is empty",
2872 __func__, inm);
2873 }
2874 #endif
2875
2876 m = mbufq_first(gq);
2877 while (m != NULL) {
2878 /*
2879 * Only merge the report into the current packet if
2880 * there is sufficient space to do so; an MLDv2 report
2881 * packet may only contain 65,535 group records.
2882 * Always use a simple mbuf chain concatentation to do this,
2883 * as large state changes for single groups may have
2884 * allocated clusters.
2885 */
2886 domerge = 0;
2887 mt = mbufq_last(scq);
2888 if (mt != NULL) {
2889 recslen = m_length(m, NULL);
2890
2891 if ((mt->m_pkthdr.vt_nrecs +
2892 m->m_pkthdr.vt_nrecs <=
2893 MLD_V2_REPORT_MAXRECS) &&
2894 (mt->m_pkthdr.len + recslen <=
2895 (inm->in6m_ifp->if_mtu - MLD_MTUSPACE)))
2896 domerge = 1;
2897 }
2898
2899 if (!domerge && mbufq_full(gq)) {
2900 CTR2(KTR_MLD,
2901 "%s: outbound queue full, skipping whole packet %p",
2902 __func__, m);
2903 mt = m->m_nextpkt;
2904 if (!docopy)
2905 m_freem(m);
2906 m = mt;
2907 continue;
2908 }
2909
2910 if (!docopy) {
2911 CTR2(KTR_MLD, "%s: dequeueing %p", __func__, m);
2912 m0 = mbufq_dequeue(gq);
2913 m = m0->m_nextpkt;
2914 } else {
2915 CTR2(KTR_MLD, "%s: copying %p", __func__, m);
2916 m0 = m_dup(m, M_NOWAIT);
2917 if (m0 == NULL)
2918 return (ENOMEM);
2919 m0->m_nextpkt = NULL;
2920 m = m->m_nextpkt;
2921 }
2922
2923 if (!domerge) {
2924 CTR3(KTR_MLD, "%s: queueing %p to scq %p)",
2925 __func__, m0, scq);
2926 mbufq_enqueue(scq, m0);
2927 } else {
2928 struct mbuf *mtl; /* last mbuf of packet mt */
2929
2930 CTR3(KTR_MLD, "%s: merging %p with ifscq tail %p)",
2931 __func__, m0, mt);
2932
2933 mtl = m_last(mt);
2934 m0->m_flags &= ~M_PKTHDR;
2935 mt->m_pkthdr.len += recslen;
2936 mt->m_pkthdr.vt_nrecs +=
2937 m0->m_pkthdr.vt_nrecs;
2938
2939 mtl->m_next = m0;
2940 }
2941 }
2942
2943 return (0);
2944 }
2945
2946 /*
2947 * Respond to a pending MLDv2 General Query.
2948 */
2949 static void
mld_v2_dispatch_general_query(struct mld_ifsoftc * mli)2950 mld_v2_dispatch_general_query(struct mld_ifsoftc *mli)
2951 {
2952 struct ifmultiaddr *ifma;
2953 struct ifnet *ifp;
2954 struct in6_multi *inm;
2955 int retval __unused;
2956
2957 NET_EPOCH_ASSERT();
2958 IN6_MULTI_LIST_LOCK_ASSERT();
2959 MLD_LOCK_ASSERT();
2960
2961 KASSERT(mli->mli_version == MLD_VERSION_2,
2962 ("%s: called when version %d", __func__, mli->mli_version));
2963
2964 /*
2965 * Check that there are some packets queued. If so, send them first.
2966 * For large number of groups the reply to general query can take
2967 * many packets, we should finish sending them before starting of
2968 * queuing the new reply.
2969 */
2970 if (!mbufq_empty(&mli->mli_gq))
2971 goto send;
2972
2973 ifp = mli->mli_ifp;
2974
2975 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
2976 inm = in6m_ifmultiaddr_get_inm(ifma);
2977 if (inm == NULL)
2978 continue;
2979 KASSERT(ifp == inm->in6m_ifp,
2980 ("%s: inconsistent ifp", __func__));
2981
2982 switch (inm->in6m_state) {
2983 case MLD_NOT_MEMBER:
2984 case MLD_SILENT_MEMBER:
2985 break;
2986 case MLD_REPORTING_MEMBER:
2987 case MLD_IDLE_MEMBER:
2988 case MLD_LAZY_MEMBER:
2989 case MLD_SLEEPING_MEMBER:
2990 case MLD_AWAKENING_MEMBER:
2991 inm->in6m_state = MLD_REPORTING_MEMBER;
2992 retval = mld_v2_enqueue_group_record(&mli->mli_gq,
2993 inm, 0, 0, 0, 0);
2994 CTR2(KTR_MLD, "%s: enqueue record = %d",
2995 __func__, retval);
2996 break;
2997 case MLD_G_QUERY_PENDING_MEMBER:
2998 case MLD_SG_QUERY_PENDING_MEMBER:
2999 case MLD_LEAVING_MEMBER:
3000 break;
3001 }
3002 }
3003
3004 send:
3005 mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST);
3006
3007 /*
3008 * Slew transmission of bursts over 500ms intervals.
3009 */
3010 if (mbufq_first(&mli->mli_gq) != NULL) {
3011 mli->mli_v2_timer = 1 + MLD_RANDOM_DELAY(
3012 MLD_RESPONSE_BURST_INTERVAL);
3013 V_interface_timers_running6 = 1;
3014 }
3015 }
3016
3017 /*
3018 * Transmit the next pending message in the output queue.
3019 *
3020 * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
3021 * MRT: Nothing needs to be done, as MLD traffic is always local to
3022 * a link and uses a link-scope multicast address.
3023 */
3024 static void
mld_dispatch_packet(struct mbuf * m)3025 mld_dispatch_packet(struct mbuf *m)
3026 {
3027 struct ip6_moptions im6o;
3028 struct ifnet *ifp;
3029 struct ifnet *oifp;
3030 struct mbuf *m0;
3031 struct mbuf *md;
3032 struct ip6_hdr *ip6;
3033 struct mld_hdr *mld;
3034 int error;
3035 int off;
3036 int type;
3037 uint32_t ifindex;
3038
3039 CTR2(KTR_MLD, "%s: transmit %p", __func__, m);
3040 NET_EPOCH_ASSERT();
3041
3042 /*
3043 * Set VNET image pointer from enqueued mbuf chain
3044 * before doing anything else. Whilst we use interface
3045 * indexes to guard against interface detach, they are
3046 * unique to each VIMAGE and must be retrieved.
3047 */
3048 ifindex = mld_restore_context(m);
3049
3050 /*
3051 * Check if the ifnet still exists. This limits the scope of
3052 * any race in the absence of a global ifp lock for low cost
3053 * (an array lookup).
3054 */
3055 ifp = ifnet_byindex(ifindex);
3056 if (ifp == NULL) {
3057 CTR3(KTR_MLD, "%s: dropped %p as ifindex %u went away.",
3058 __func__, m, ifindex);
3059 m_freem(m);
3060 IP6STAT_INC(ip6s_noroute);
3061 goto out;
3062 }
3063
3064 im6o.im6o_multicast_hlim = 1;
3065 im6o.im6o_multicast_loop = (V_ip6_mrouter != NULL);
3066 im6o.im6o_multicast_ifp = ifp;
3067
3068 if (m->m_flags & M_MLDV1) {
3069 m0 = m;
3070 } else {
3071 m0 = mld_v2_encap_report(ifp, m);
3072 if (m0 == NULL) {
3073 CTR2(KTR_MLD, "%s: dropped %p", __func__, m);
3074 IP6STAT_INC(ip6s_odropped);
3075 goto out;
3076 }
3077 }
3078
3079 mld_scrub_context(m0);
3080 m_clrprotoflags(m);
3081 m0->m_pkthdr.rcvif = V_loif;
3082
3083 ip6 = mtod(m0, struct ip6_hdr *);
3084 #if 0
3085 (void)in6_setscope(&ip6->ip6_dst, ifp, NULL); /* XXX LOR */
3086 #else
3087 /*
3088 * XXX XXX Break some KPI rules to prevent an LOR which would
3089 * occur if we called in6_setscope() at transmission.
3090 * See comments at top of file.
3091 */
3092 MLD_EMBEDSCOPE(&ip6->ip6_dst, ifp->if_index);
3093 #endif
3094
3095 /*
3096 * Retrieve the ICMPv6 type before handoff to ip6_output(),
3097 * so we can bump the stats.
3098 */
3099 md = m_getptr(m0, sizeof(struct ip6_hdr), &off);
3100 mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off);
3101 type = mld->mld_type;
3102
3103 oifp = NULL;
3104 error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o,
3105 &oifp, NULL);
3106 if (error) {
3107 CTR3(KTR_MLD, "%s: ip6_output(%p) = %d", __func__, m0, error);
3108 goto out;
3109 }
3110 ICMP6STAT_INC2(icp6s_outhist, type);
3111 if (oifp != NULL) {
3112 icmp6_ifstat_inc(oifp, ifs6_out_msg);
3113 switch (type) {
3114 case MLD_LISTENER_REPORT:
3115 case MLDV2_LISTENER_REPORT:
3116 icmp6_ifstat_inc(oifp, ifs6_out_mldreport);
3117 break;
3118 case MLD_LISTENER_DONE:
3119 icmp6_ifstat_inc(oifp, ifs6_out_mlddone);
3120 break;
3121 }
3122 }
3123 out:
3124 return;
3125 }
3126
3127 /*
3128 * Encapsulate an MLDv2 report.
3129 *
3130 * KAME IPv6 requires that hop-by-hop options be passed separately,
3131 * and that the IPv6 header be prepended in a separate mbuf.
3132 *
3133 * Returns a pointer to the new mbuf chain head, or NULL if the
3134 * allocation failed.
3135 */
3136 static struct mbuf *
mld_v2_encap_report(struct ifnet * ifp,struct mbuf * m)3137 mld_v2_encap_report(struct ifnet *ifp, struct mbuf *m)
3138 {
3139 struct mbuf *mh;
3140 struct mldv2_report *mld;
3141 struct ip6_hdr *ip6;
3142 struct in6_ifaddr *ia;
3143 int mldreclen;
3144
3145 KASSERT(ifp != NULL, ("%s: null ifp", __func__));
3146 KASSERT((m->m_flags & M_PKTHDR),
3147 ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
3148
3149 /*
3150 * RFC3590: OK to send as :: or tentative during DAD.
3151 */
3152 NET_EPOCH_ASSERT();
3153 ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
3154 if (ia == NULL)
3155 CTR1(KTR_MLD, "%s: warning: ia is NULL", __func__);
3156
3157 mh = m_gethdr(M_NOWAIT, MT_DATA);
3158 if (mh == NULL) {
3159 if (ia != NULL)
3160 ifa_free(&ia->ia_ifa);
3161 m_freem(m);
3162 return (NULL);
3163 }
3164 M_ALIGN(mh, sizeof(struct ip6_hdr) + sizeof(struct mldv2_report));
3165
3166 mldreclen = m_length(m, NULL);
3167 CTR2(KTR_MLD, "%s: mldreclen is %d", __func__, mldreclen);
3168
3169 mh->m_len = sizeof(struct ip6_hdr) + sizeof(struct mldv2_report);
3170 mh->m_pkthdr.len = sizeof(struct ip6_hdr) +
3171 sizeof(struct mldv2_report) + mldreclen;
3172
3173 ip6 = mtod(mh, struct ip6_hdr *);
3174 ip6->ip6_flow = 0;
3175 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
3176 ip6->ip6_vfc |= IPV6_VERSION;
3177 ip6->ip6_nxt = IPPROTO_ICMPV6;
3178 ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
3179 if (ia != NULL)
3180 ifa_free(&ia->ia_ifa);
3181 ip6->ip6_dst = in6addr_linklocal_allv2routers;
3182 /* scope ID will be set in netisr */
3183
3184 mld = (struct mldv2_report *)(ip6 + 1);
3185 mld->mld_type = MLDV2_LISTENER_REPORT;
3186 mld->mld_code = 0;
3187 mld->mld_cksum = 0;
3188 mld->mld_v2_reserved = 0;
3189 mld->mld_v2_numrecs = htons(m->m_pkthdr.vt_nrecs);
3190 m->m_pkthdr.vt_nrecs = 0;
3191
3192 mh->m_next = m;
3193 mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
3194 sizeof(struct ip6_hdr), sizeof(struct mldv2_report) + mldreclen);
3195 return (mh);
3196 }
3197
3198 #ifdef KTR
3199 static char *
mld_rec_type_to_str(const int type)3200 mld_rec_type_to_str(const int type)
3201 {
3202
3203 switch (type) {
3204 case MLD_CHANGE_TO_EXCLUDE_MODE:
3205 return "TO_EX";
3206 break;
3207 case MLD_CHANGE_TO_INCLUDE_MODE:
3208 return "TO_IN";
3209 break;
3210 case MLD_MODE_IS_EXCLUDE:
3211 return "MODE_EX";
3212 break;
3213 case MLD_MODE_IS_INCLUDE:
3214 return "MODE_IN";
3215 break;
3216 case MLD_ALLOW_NEW_SOURCES:
3217 return "ALLOW_NEW";
3218 break;
3219 case MLD_BLOCK_OLD_SOURCES:
3220 return "BLOCK_OLD";
3221 break;
3222 default:
3223 break;
3224 }
3225 return "unknown";
3226 }
3227 #endif
3228
3229 static void
mld_init(void * unused __unused)3230 mld_init(void *unused __unused)
3231 {
3232
3233 CTR1(KTR_MLD, "%s: initializing", __func__);
3234 MLD_LOCK_INIT();
3235
3236 ip6_initpktopts(&mld_po);
3237 mld_po.ip6po_hlim = 1;
3238 mld_po.ip6po_hbh = &mld_ra.hbh;
3239 mld_po.ip6po_prefer_tempaddr = IP6PO_TEMPADDR_NOTPREFER;
3240 mld_po.ip6po_flags = IP6PO_DONTFRAG;
3241 mld_po.ip6po_valid = IP6PO_VALID_HLIM | IP6PO_VALID_HBH;
3242
3243 callout_init(&mldslow_callout, 1);
3244 callout_reset(&mldslow_callout, hz / MLD_SLOWHZ, mld_slowtimo, NULL);
3245 callout_init(&mldfast_callout, 1);
3246 callout_reset(&mldfast_callout, hz / MLD_FASTHZ, mld_fasttimo, NULL);
3247 }
3248 SYSINIT(mld_init, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_init, NULL);
3249
3250 static void
mld_uninit(void * unused __unused)3251 mld_uninit(void *unused __unused)
3252 {
3253
3254 CTR1(KTR_MLD, "%s: tearing down", __func__);
3255 callout_drain(&mldslow_callout);
3256 callout_drain(&mldfast_callout);
3257 MLD_LOCK_DESTROY();
3258 }
3259 SYSUNINIT(mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_uninit, NULL);
3260
3261 static void
vnet_mld_init(const void * unused __unused)3262 vnet_mld_init(const void *unused __unused)
3263 {
3264
3265 CTR1(KTR_MLD, "%s: initializing", __func__);
3266
3267 LIST_INIT(&V_mli_head);
3268 }
3269 VNET_SYSINIT(vnet_mld_init, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_init,
3270 NULL);
3271
3272 static void
vnet_mld_uninit(const void * unused __unused)3273 vnet_mld_uninit(const void *unused __unused)
3274 {
3275
3276 /* This can happen if we shutdown the network stack. */
3277 CTR1(KTR_MLD, "%s: tearing down", __func__);
3278 }
3279 VNET_SYSUNINIT(vnet_mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_uninit,
3280 NULL);
3281
3282 static int
mld_modevent(module_t mod,int type,void * unused __unused)3283 mld_modevent(module_t mod, int type, void *unused __unused)
3284 {
3285
3286 switch (type) {
3287 case MOD_LOAD:
3288 case MOD_UNLOAD:
3289 break;
3290 default:
3291 return (EOPNOTSUPP);
3292 }
3293 return (0);
3294 }
3295
3296 static moduledata_t mld_mod = {
3297 "mld",
3298 mld_modevent,
3299 0
3300 };
3301 DECLARE_MODULE(mld, mld_mod, SI_SUB_PROTO_MC, SI_ORDER_ANY);
3302