1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2007-2009 Bruce Simpson.
5 * Copyright (c) 2005 Robert N. M. Watson.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote
17 *    products derived from this software without specific prior written
18 *    permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33/*
34 * IPv4 multicast socket, group, and socket option processing module.
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kernel.h>
40#include <sys/lock.h>
41#include <sys/malloc.h>
42#include <sys/mbuf.h>
43#include <sys/protosw.h>
44#include <sys/socket.h>
45#include <sys/socketvar.h>
46#include <sys/protosw.h>
47#include <sys/sysctl.h>
48#include <sys/ktr.h>
49#include <sys/taskqueue.h>
50#include <sys/tree.h>
51
52#include <net/if.h>
53#include <net/if_var.h>
54#include <net/if_dl.h>
55#include <net/route.h>
56#include <net/route/nhop.h>
57#include <net/vnet.h>
58
59#include <net/ethernet.h>
60
61#include <netinet/in.h>
62#include <netinet/in_systm.h>
63#include <netinet/in_fib.h>
64#include <netinet/in_pcb.h>
65#include <netinet/in_var.h>
66#include <net/if_private.h>
67#include <netinet/ip_var.h>
68#include <netinet/igmp_var.h>
69
70#ifndef KTR_IGMPV3
71#define KTR_IGMPV3 KTR_INET
72#endif
73
74#ifndef __SOCKUNION_DECLARED
75union sockunion {
76	struct sockaddr_storage	ss;
77	struct sockaddr		sa;
78	struct sockaddr_dl	sdl;
79	struct sockaddr_in	sin;
80};
81typedef union sockunion sockunion_t;
82#define __SOCKUNION_DECLARED
83#endif /* __SOCKUNION_DECLARED */
84
85static MALLOC_DEFINE(M_INMFILTER, "in_mfilter",
86    "IPv4 multicast PCB-layer source filter");
87static MALLOC_DEFINE(M_IPMADDR, "in_multi", "IPv4 multicast group");
88static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "IPv4 multicast options");
89static MALLOC_DEFINE(M_IPMSOURCE, "ip_msource",
90    "IPv4 multicast IGMP-layer source filter");
91
92/*
93 * Locking:
94 *
95 * - Lock order is: IN_MULTI_LOCK, INP_WLOCK, IN_MULTI_LIST_LOCK, IGMP_LOCK,
96 *                  IF_ADDR_LOCK.
97 * - The IF_ADDR_LOCK is implicitly taken by inm_lookup() earlier, however
98 *   it can be taken by code in net/if.c also.
99 * - ip_moptions and in_mfilter are covered by the INP_WLOCK.
100 *
101 * struct in_multi is covered by IN_MULTI_LIST_LOCK. There isn't strictly
102 * any need for in_multi itself to be virtualized -- it is bound to an ifp
103 * anyway no matter what happens.
104 */
105struct mtx in_multi_list_mtx;
106MTX_SYSINIT(in_multi_mtx, &in_multi_list_mtx, "in_multi_list_mtx", MTX_DEF);
107
108struct mtx in_multi_free_mtx;
109MTX_SYSINIT(in_multi_free_mtx, &in_multi_free_mtx, "in_multi_free_mtx", MTX_DEF);
110
111struct sx in_multi_sx;
112SX_SYSINIT(in_multi_sx, &in_multi_sx, "in_multi_sx");
113
114/*
115 * Functions with non-static linkage defined in this file should be
116 * declared in in_var.h:
117 *  imo_multi_filter()
118 *  in_joingroup()
119 *  in_joingroup_locked()
120 *  in_leavegroup()
121 *  in_leavegroup_locked()
122 * and ip_var.h:
123 *  inp_freemoptions()
124 *  inp_getmoptions()
125 *  inp_setmoptions()
126 */
127static void	imf_commit(struct in_mfilter *);
128static int	imf_get_source(struct in_mfilter *imf,
129		    const struct sockaddr_in *psin,
130		    struct in_msource **);
131static struct in_msource *
132		imf_graft(struct in_mfilter *, const uint8_t,
133		    const struct sockaddr_in *);
134static void	imf_leave(struct in_mfilter *);
135static int	imf_prune(struct in_mfilter *, const struct sockaddr_in *);
136static void	imf_purge(struct in_mfilter *);
137static void	imf_rollback(struct in_mfilter *);
138static void	imf_reap(struct in_mfilter *);
139static struct in_mfilter *
140		imo_match_group(const struct ip_moptions *,
141		    const struct ifnet *, const struct sockaddr *);
142static struct in_msource *
143		imo_match_source(struct in_mfilter *, const struct sockaddr *);
144static void	ims_merge(struct ip_msource *ims,
145		    const struct in_msource *lims, const int rollback);
146static int	in_getmulti(struct ifnet *, const struct in_addr *,
147		    struct in_multi **);
148static int	inm_get_source(struct in_multi *inm, const in_addr_t haddr,
149		    const int noalloc, struct ip_msource **pims);
150#ifdef KTR
151static int	inm_is_ifp_detached(const struct in_multi *);
152#endif
153static int	inm_merge(struct in_multi *, /*const*/ struct in_mfilter *);
154static void	inm_purge(struct in_multi *);
155static void	inm_reap(struct in_multi *);
156static void inm_release(struct in_multi *);
157static struct ip_moptions *
158		inp_findmoptions(struct inpcb *);
159static int	inp_get_source_filters(struct inpcb *, struct sockopt *);
160static int	inp_join_group(struct inpcb *, struct sockopt *);
161static int	inp_leave_group(struct inpcb *, struct sockopt *);
162static struct ifnet *
163		inp_lookup_mcast_ifp(const struct inpcb *,
164		    const struct sockaddr_in *, const struct in_addr);
165static int	inp_block_unblock_source(struct inpcb *, struct sockopt *);
166static int	inp_set_multicast_if(struct inpcb *, struct sockopt *);
167static int	inp_set_source_filters(struct inpcb *, struct sockopt *);
168static int	sysctl_ip_mcast_filters(SYSCTL_HANDLER_ARGS);
169
170static SYSCTL_NODE(_net_inet_ip, OID_AUTO, mcast,
171    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
172    "IPv4 multicast");
173
174static u_long in_mcast_maxgrpsrc = IP_MAX_GROUP_SRC_FILTER;
175SYSCTL_ULONG(_net_inet_ip_mcast, OID_AUTO, maxgrpsrc,
176    CTLFLAG_RWTUN, &in_mcast_maxgrpsrc, 0,
177    "Max source filters per group");
178
179static u_long in_mcast_maxsocksrc = IP_MAX_SOCK_SRC_FILTER;
180SYSCTL_ULONG(_net_inet_ip_mcast, OID_AUTO, maxsocksrc,
181    CTLFLAG_RWTUN, &in_mcast_maxsocksrc, 0,
182    "Max source filters per socket");
183
184int in_mcast_loop = IP_DEFAULT_MULTICAST_LOOP;
185SYSCTL_INT(_net_inet_ip_mcast, OID_AUTO, loop, CTLFLAG_RWTUN,
186    &in_mcast_loop, 0, "Loopback multicast datagrams by default");
187
188static SYSCTL_NODE(_net_inet_ip_mcast, OID_AUTO, filters,
189    CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_ip_mcast_filters,
190    "Per-interface stack-wide source filters");
191
192#ifdef KTR
193/*
194 * Inline function which wraps assertions for a valid ifp.
195 * The ifnet layer will set the ifma's ifp pointer to NULL if the ifp
196 * is detached.
197 */
198static int __inline
199inm_is_ifp_detached(const struct in_multi *inm)
200{
201	struct ifnet *ifp;
202
203	KASSERT(inm->inm_ifma != NULL, ("%s: no ifma", __func__));
204	ifp = inm->inm_ifma->ifma_ifp;
205	if (ifp != NULL) {
206		/*
207		 * Sanity check that netinet's notion of ifp is the
208		 * same as net's.
209		 */
210		KASSERT(inm->inm_ifp == ifp, ("%s: bad ifp", __func__));
211	}
212
213	return (ifp == NULL);
214}
215#endif
216
217/*
218 * Interface detach can happen in a taskqueue thread context, so we must use a
219 * dedicated thread to avoid deadlocks when draining inm_release tasks.
220 */
221TASKQUEUE_DEFINE_THREAD(inm_free);
222static struct in_multi_head inm_free_list = SLIST_HEAD_INITIALIZER();
223static void inm_release_task(void *arg __unused, int pending __unused);
224static struct task inm_free_task = TASK_INITIALIZER(0, inm_release_task, NULL);
225
226void
227inm_release_wait(void *arg __unused)
228{
229
230	/*
231	 * Make sure all pending multicast addresses are freed before
232	 * the VNET or network device is destroyed:
233	 */
234	taskqueue_drain(taskqueue_inm_free, &inm_free_task);
235}
236#ifdef VIMAGE
237/* XXX-BZ FIXME, see D24914. */
238VNET_SYSUNINIT(inm_release_wait, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, inm_release_wait, NULL);
239#endif
240
241void
242inm_release_list_deferred(struct in_multi_head *inmh)
243{
244
245	if (SLIST_EMPTY(inmh))
246		return;
247	mtx_lock(&in_multi_free_mtx);
248	SLIST_CONCAT(&inm_free_list, inmh, in_multi, inm_nrele);
249	mtx_unlock(&in_multi_free_mtx);
250	taskqueue_enqueue(taskqueue_inm_free, &inm_free_task);
251}
252
253void
254inm_disconnect(struct in_multi *inm)
255{
256	struct ifnet *ifp;
257	struct ifmultiaddr *ifma, *ll_ifma;
258
259	ifp = inm->inm_ifp;
260	IF_ADDR_WLOCK_ASSERT(ifp);
261	ifma = inm->inm_ifma;
262
263	if_ref(ifp);
264	if (ifma->ifma_flags & IFMA_F_ENQUEUED) {
265		CK_STAILQ_REMOVE(&ifp->if_multiaddrs, ifma, ifmultiaddr, ifma_link);
266		ifma->ifma_flags &= ~IFMA_F_ENQUEUED;
267	}
268	MCDPRINTF("removed ifma: %p from %s\n", ifma, ifp->if_xname);
269	if ((ll_ifma = ifma->ifma_llifma) != NULL) {
270		MPASS(ifma != ll_ifma);
271		ifma->ifma_llifma = NULL;
272		MPASS(ll_ifma->ifma_llifma == NULL);
273		MPASS(ll_ifma->ifma_ifp == ifp);
274		if (--ll_ifma->ifma_refcount == 0) {
275			if (ll_ifma->ifma_flags & IFMA_F_ENQUEUED) {
276				CK_STAILQ_REMOVE(&ifp->if_multiaddrs, ll_ifma, ifmultiaddr, ifma_link);
277				ll_ifma->ifma_flags &= ~IFMA_F_ENQUEUED;
278			}
279			MCDPRINTF("removed ll_ifma: %p from %s\n", ll_ifma, ifp->if_xname);
280			if_freemulti(ll_ifma);
281		}
282	}
283}
284
285void
286inm_release_deferred(struct in_multi *inm)
287{
288	struct in_multi_head tmp;
289
290	IN_MULTI_LIST_LOCK_ASSERT();
291	MPASS(inm->inm_refcount > 0);
292	if (--inm->inm_refcount == 0) {
293		SLIST_INIT(&tmp);
294		inm_disconnect(inm);
295		inm->inm_ifma->ifma_protospec = NULL;
296		SLIST_INSERT_HEAD(&tmp, inm, inm_nrele);
297		inm_release_list_deferred(&tmp);
298	}
299}
300
301static void
302inm_release_task(void *arg __unused, int pending __unused)
303{
304	struct in_multi_head inm_free_tmp;
305	struct in_multi *inm, *tinm;
306
307	SLIST_INIT(&inm_free_tmp);
308	mtx_lock(&in_multi_free_mtx);
309	SLIST_CONCAT(&inm_free_tmp, &inm_free_list, in_multi, inm_nrele);
310	mtx_unlock(&in_multi_free_mtx);
311	IN_MULTI_LOCK();
312	SLIST_FOREACH_SAFE(inm, &inm_free_tmp, inm_nrele, tinm) {
313		SLIST_REMOVE_HEAD(&inm_free_tmp, inm_nrele);
314		MPASS(inm);
315		inm_release(inm);
316	}
317	IN_MULTI_UNLOCK();
318}
319
320/*
321 * Initialize an in_mfilter structure to a known state at t0, t1
322 * with an empty source filter list.
323 */
324static __inline void
325imf_init(struct in_mfilter *imf, const int st0, const int st1)
326{
327	memset(imf, 0, sizeof(struct in_mfilter));
328	RB_INIT(&imf->imf_sources);
329	imf->imf_st[0] = st0;
330	imf->imf_st[1] = st1;
331}
332
333struct in_mfilter *
334ip_mfilter_alloc(const int mflags, const int st0, const int st1)
335{
336	struct in_mfilter *imf;
337
338	imf = malloc(sizeof(*imf), M_INMFILTER, mflags);
339	if (imf != NULL)
340		imf_init(imf, st0, st1);
341
342	return (imf);
343}
344
345void
346ip_mfilter_free(struct in_mfilter *imf)
347{
348
349	imf_purge(imf);
350	free(imf, M_INMFILTER);
351}
352
353/*
354 * Function for looking up an in_multi record for an IPv4 multicast address
355 * on a given interface. ifp must be valid. If no record found, return NULL.
356 * The IN_MULTI_LIST_LOCK and IF_ADDR_LOCK on ifp must be held.
357 */
358struct in_multi *
359inm_lookup_locked(struct ifnet *ifp, const struct in_addr ina)
360{
361	struct ifmultiaddr *ifma;
362	struct in_multi *inm;
363
364	IN_MULTI_LIST_LOCK_ASSERT();
365	IF_ADDR_LOCK_ASSERT(ifp);
366
367	CK_STAILQ_FOREACH(ifma, &((ifp)->if_multiaddrs), ifma_link) {
368		inm = inm_ifmultiaddr_get_inm(ifma);
369		if (inm == NULL)
370			continue;
371		if (inm->inm_addr.s_addr == ina.s_addr)
372			return (inm);
373	}
374	return (NULL);
375}
376
377/*
378 * Wrapper for inm_lookup_locked().
379 * The IF_ADDR_LOCK will be taken on ifp and released on return.
380 */
381struct in_multi *
382inm_lookup(struct ifnet *ifp, const struct in_addr ina)
383{
384	struct epoch_tracker et;
385	struct in_multi *inm;
386
387	IN_MULTI_LIST_LOCK_ASSERT();
388	NET_EPOCH_ENTER(et);
389
390	inm = inm_lookup_locked(ifp, ina);
391	NET_EPOCH_EXIT(et);
392
393	return (inm);
394}
395
396/*
397 * Find an IPv4 multicast group entry for this ip_moptions instance
398 * which matches the specified group, and optionally an interface.
399 * Return its index into the array, or -1 if not found.
400 */
401static struct in_mfilter *
402imo_match_group(const struct ip_moptions *imo, const struct ifnet *ifp,
403    const struct sockaddr *group)
404{
405	const struct sockaddr_in *gsin;
406	struct in_mfilter *imf;
407	struct in_multi	*inm;
408
409	gsin = (const struct sockaddr_in *)group;
410
411	IP_MFILTER_FOREACH(imf, &imo->imo_head) {
412		inm = imf->imf_inm;
413		if (inm == NULL)
414			continue;
415		if ((ifp == NULL || (inm->inm_ifp == ifp)) &&
416		    in_hosteq(inm->inm_addr, gsin->sin_addr)) {
417			break;
418		}
419	}
420	return (imf);
421}
422
423/*
424 * Find an IPv4 multicast source entry for this imo which matches
425 * the given group index for this socket, and source address.
426 *
427 * NOTE: This does not check if the entry is in-mode, merely if
428 * it exists, which may not be the desired behaviour.
429 */
430static struct in_msource *
431imo_match_source(struct in_mfilter *imf, const struct sockaddr *src)
432{
433	struct ip_msource	 find;
434	struct ip_msource	*ims;
435	const sockunion_t	*psa;
436
437	KASSERT(src->sa_family == AF_INET, ("%s: !AF_INET", __func__));
438
439	/* Source trees are keyed in host byte order. */
440	psa = (const sockunion_t *)src;
441	find.ims_haddr = ntohl(psa->sin.sin_addr.s_addr);
442	ims = RB_FIND(ip_msource_tree, &imf->imf_sources, &find);
443
444	return ((struct in_msource *)ims);
445}
446
447/*
448 * Perform filtering for multicast datagrams on a socket by group and source.
449 *
450 * Returns 0 if a datagram should be allowed through, or various error codes
451 * if the socket was not a member of the group, or the source was muted, etc.
452 */
453int
454imo_multi_filter(const struct ip_moptions *imo, const struct ifnet *ifp,
455    const struct sockaddr *group, const struct sockaddr *src)
456{
457	struct in_mfilter *imf;
458	struct in_msource *ims;
459	int mode;
460
461	KASSERT(ifp != NULL, ("%s: null ifp", __func__));
462
463	imf = imo_match_group(imo, ifp, group);
464	if (imf == NULL)
465		return (MCAST_NOTGMEMBER);
466
467	/*
468	 * Check if the source was included in an (S,G) join.
469	 * Allow reception on exclusive memberships by default,
470	 * reject reception on inclusive memberships by default.
471	 * Exclude source only if an in-mode exclude filter exists.
472	 * Include source only if an in-mode include filter exists.
473	 * NOTE: We are comparing group state here at IGMP t1 (now)
474	 * with socket-layer t0 (since last downcall).
475	 */
476	mode = imf->imf_st[1];
477	ims = imo_match_source(imf, src);
478
479	if ((ims == NULL && mode == MCAST_INCLUDE) ||
480	    (ims != NULL && ims->imsl_st[0] == MCAST_EXCLUDE))
481		return (MCAST_NOTSMEMBER);
482
483	return (MCAST_PASS);
484}
485
486/*
487 * Find and return a reference to an in_multi record for (ifp, group),
488 * and bump its reference count.
489 * If one does not exist, try to allocate it, and update link-layer multicast
490 * filters on ifp to listen for group.
491 * Assumes the IN_MULTI lock is held across the call.
492 * Return 0 if successful, otherwise return an appropriate error code.
493 */
494static int
495in_getmulti(struct ifnet *ifp, const struct in_addr *group,
496    struct in_multi **pinm)
497{
498	struct sockaddr_in	 gsin;
499	struct ifmultiaddr	*ifma;
500	struct in_ifinfo	*ii;
501	struct in_multi		*inm;
502	int error;
503
504	IN_MULTI_LOCK_ASSERT();
505
506	ii = (struct in_ifinfo *)ifp->if_afdata[AF_INET];
507	IN_MULTI_LIST_LOCK();
508	inm = inm_lookup(ifp, *group);
509	if (inm != NULL) {
510		/*
511		 * If we already joined this group, just bump the
512		 * refcount and return it.
513		 */
514		KASSERT(inm->inm_refcount >= 1,
515		    ("%s: bad refcount %d", __func__, inm->inm_refcount));
516		inm_acquire_locked(inm);
517		*pinm = inm;
518	}
519	IN_MULTI_LIST_UNLOCK();
520	if (inm != NULL)
521		return (0);
522
523	memset(&gsin, 0, sizeof(gsin));
524	gsin.sin_family = AF_INET;
525	gsin.sin_len = sizeof(struct sockaddr_in);
526	gsin.sin_addr = *group;
527
528	/*
529	 * Check if a link-layer group is already associated
530	 * with this network-layer group on the given ifnet.
531	 */
532	error = if_addmulti(ifp, (struct sockaddr *)&gsin, &ifma);
533	if (error != 0)
534		return (error);
535
536	/* XXX ifma_protospec must be covered by IF_ADDR_LOCK */
537	IN_MULTI_LIST_LOCK();
538	IF_ADDR_WLOCK(ifp);
539
540	/*
541	 * If something other than netinet is occupying the link-layer
542	 * group, print a meaningful error message and back out of
543	 * the allocation.
544	 * Otherwise, bump the refcount on the existing network-layer
545	 * group association and return it.
546	 */
547	if (ifma->ifma_protospec != NULL) {
548		inm = (struct in_multi *)ifma->ifma_protospec;
549#ifdef INVARIANTS
550		KASSERT(ifma->ifma_addr != NULL, ("%s: no ifma_addr",
551		    __func__));
552		KASSERT(ifma->ifma_addr->sa_family == AF_INET,
553		    ("%s: ifma not AF_INET", __func__));
554		KASSERT(inm != NULL, ("%s: no ifma_protospec", __func__));
555		if (inm->inm_ifma != ifma || inm->inm_ifp != ifp ||
556		    !in_hosteq(inm->inm_addr, *group)) {
557			char addrbuf[INET_ADDRSTRLEN];
558
559			panic("%s: ifma %p is inconsistent with %p (%s)",
560			    __func__, ifma, inm, inet_ntoa_r(*group, addrbuf));
561		}
562#endif
563		inm_acquire_locked(inm);
564		*pinm = inm;
565		goto out_locked;
566	}
567
568	IF_ADDR_WLOCK_ASSERT(ifp);
569
570	/*
571	 * A new in_multi record is needed; allocate and initialize it.
572	 * We DO NOT perform an IGMP join as the in_ layer may need to
573	 * push an initial source list down to IGMP to support SSM.
574	 *
575	 * The initial source filter state is INCLUDE, {} as per the RFC.
576	 */
577	inm = malloc(sizeof(*inm), M_IPMADDR, M_NOWAIT | M_ZERO);
578	if (inm == NULL) {
579		IF_ADDR_WUNLOCK(ifp);
580		IN_MULTI_LIST_UNLOCK();
581		if_delmulti_ifma(ifma);
582		return (ENOMEM);
583	}
584	inm->inm_addr = *group;
585	inm->inm_ifp = ifp;
586	inm->inm_igi = ii->ii_igmp;
587	inm->inm_ifma = ifma;
588	inm->inm_refcount = 1;
589	inm->inm_state = IGMP_NOT_MEMBER;
590	mbufq_init(&inm->inm_scq, IGMP_MAX_STATE_CHANGES);
591	inm->inm_st[0].iss_fmode = MCAST_UNDEFINED;
592	inm->inm_st[1].iss_fmode = MCAST_UNDEFINED;
593	RB_INIT(&inm->inm_srcs);
594
595	ifma->ifma_protospec = inm;
596
597	*pinm = inm;
598 out_locked:
599	IF_ADDR_WUNLOCK(ifp);
600	IN_MULTI_LIST_UNLOCK();
601	return (0);
602}
603
604/*
605 * Drop a reference to an in_multi record.
606 *
607 * If the refcount drops to 0, free the in_multi record and
608 * delete the underlying link-layer membership.
609 */
610static void
611inm_release(struct in_multi *inm)
612{
613	struct ifmultiaddr *ifma;
614	struct ifnet *ifp;
615
616	CTR2(KTR_IGMPV3, "%s: refcount is %d", __func__, inm->inm_refcount);
617	MPASS(inm->inm_refcount == 0);
618	CTR2(KTR_IGMPV3, "%s: freeing inm %p", __func__, inm);
619
620	ifma = inm->inm_ifma;
621	ifp = inm->inm_ifp;
622
623	/* XXX this access is not covered by IF_ADDR_LOCK */
624	CTR2(KTR_IGMPV3, "%s: purging ifma %p", __func__, ifma);
625	if (ifp != NULL) {
626		CURVNET_SET(ifp->if_vnet);
627		inm_purge(inm);
628		free(inm, M_IPMADDR);
629		if_delmulti_ifma_flags(ifma, 1);
630		CURVNET_RESTORE();
631		if_rele(ifp);
632	} else {
633		inm_purge(inm);
634		free(inm, M_IPMADDR);
635		if_delmulti_ifma_flags(ifma, 1);
636	}
637}
638
639/*
640 * Clear recorded source entries for a group.
641 * Used by the IGMP code. Caller must hold the IN_MULTI lock.
642 * FIXME: Should reap.
643 */
644void
645inm_clear_recorded(struct in_multi *inm)
646{
647	struct ip_msource	*ims;
648
649	IN_MULTI_LIST_LOCK_ASSERT();
650
651	RB_FOREACH(ims, ip_msource_tree, &inm->inm_srcs) {
652		if (ims->ims_stp) {
653			ims->ims_stp = 0;
654			--inm->inm_st[1].iss_rec;
655		}
656	}
657	KASSERT(inm->inm_st[1].iss_rec == 0,
658	    ("%s: iss_rec %d not 0", __func__, inm->inm_st[1].iss_rec));
659}
660
661/*
662 * Record a source as pending for a Source-Group IGMPv3 query.
663 * This lives here as it modifies the shared tree.
664 *
665 * inm is the group descriptor.
666 * naddr is the address of the source to record in network-byte order.
667 *
668 * If the net.inet.igmp.sgalloc sysctl is non-zero, we will
669 * lazy-allocate a source node in response to an SG query.
670 * Otherwise, no allocation is performed. This saves some memory
671 * with the trade-off that the source will not be reported to the
672 * router if joined in the window between the query response and
673 * the group actually being joined on the local host.
674 *
675 * VIMAGE: XXX: Currently the igmp_sgalloc feature has been removed.
676 * This turns off the allocation of a recorded source entry if
677 * the group has not been joined.
678 *
679 * Return 0 if the source didn't exist or was already marked as recorded.
680 * Return 1 if the source was marked as recorded by this function.
681 * Return <0 if any error occurred (negated errno code).
682 */
683int
684inm_record_source(struct in_multi *inm, const in_addr_t naddr)
685{
686	struct ip_msource	 find;
687	struct ip_msource	*ims, *nims;
688
689	IN_MULTI_LIST_LOCK_ASSERT();
690
691	find.ims_haddr = ntohl(naddr);
692	ims = RB_FIND(ip_msource_tree, &inm->inm_srcs, &find);
693	if (ims && ims->ims_stp)
694		return (0);
695	if (ims == NULL) {
696		if (inm->inm_nsrc == in_mcast_maxgrpsrc)
697			return (-ENOSPC);
698		nims = malloc(sizeof(struct ip_msource), M_IPMSOURCE,
699		    M_NOWAIT | M_ZERO);
700		if (nims == NULL)
701			return (-ENOMEM);
702		nims->ims_haddr = find.ims_haddr;
703		RB_INSERT(ip_msource_tree, &inm->inm_srcs, nims);
704		++inm->inm_nsrc;
705		ims = nims;
706	}
707
708	/*
709	 * Mark the source as recorded and update the recorded
710	 * source count.
711	 */
712	++ims->ims_stp;
713	++inm->inm_st[1].iss_rec;
714
715	return (1);
716}
717
718/*
719 * Return a pointer to an in_msource owned by an in_mfilter,
720 * given its source address.
721 * Lazy-allocate if needed. If this is a new entry its filter state is
722 * undefined at t0.
723 *
724 * imf is the filter set being modified.
725 * haddr is the source address in *host* byte-order.
726 *
727 * SMPng: May be called with locks held; malloc must not block.
728 */
729static int
730imf_get_source(struct in_mfilter *imf, const struct sockaddr_in *psin,
731    struct in_msource **plims)
732{
733	struct ip_msource	 find;
734	struct ip_msource	*ims, *nims;
735	struct in_msource	*lims;
736	int			 error;
737
738	error = 0;
739	ims = NULL;
740	lims = NULL;
741
742	/* key is host byte order */
743	find.ims_haddr = ntohl(psin->sin_addr.s_addr);
744	ims = RB_FIND(ip_msource_tree, &imf->imf_sources, &find);
745	lims = (struct in_msource *)ims;
746	if (lims == NULL) {
747		if (imf->imf_nsrc == in_mcast_maxsocksrc)
748			return (ENOSPC);
749		nims = malloc(sizeof(struct in_msource), M_INMFILTER,
750		    M_NOWAIT | M_ZERO);
751		if (nims == NULL)
752			return (ENOMEM);
753		lims = (struct in_msource *)nims;
754		lims->ims_haddr = find.ims_haddr;
755		lims->imsl_st[0] = MCAST_UNDEFINED;
756		RB_INSERT(ip_msource_tree, &imf->imf_sources, nims);
757		++imf->imf_nsrc;
758	}
759
760	*plims = lims;
761
762	return (error);
763}
764
765/*
766 * Graft a source entry into an existing socket-layer filter set,
767 * maintaining any required invariants and checking allocations.
768 *
769 * The source is marked as being in the new filter mode at t1.
770 *
771 * Return the pointer to the new node, otherwise return NULL.
772 */
773static struct in_msource *
774imf_graft(struct in_mfilter *imf, const uint8_t st1,
775    const struct sockaddr_in *psin)
776{
777	struct ip_msource	*nims;
778	struct in_msource	*lims;
779
780	nims = malloc(sizeof(struct in_msource), M_INMFILTER,
781	    M_NOWAIT | M_ZERO);
782	if (nims == NULL)
783		return (NULL);
784	lims = (struct in_msource *)nims;
785	lims->ims_haddr = ntohl(psin->sin_addr.s_addr);
786	lims->imsl_st[0] = MCAST_UNDEFINED;
787	lims->imsl_st[1] = st1;
788	RB_INSERT(ip_msource_tree, &imf->imf_sources, nims);
789	++imf->imf_nsrc;
790
791	return (lims);
792}
793
794/*
795 * Prune a source entry from an existing socket-layer filter set,
796 * maintaining any required invariants and checking allocations.
797 *
798 * The source is marked as being left at t1, it is not freed.
799 *
800 * Return 0 if no error occurred, otherwise return an errno value.
801 */
802static int
803imf_prune(struct in_mfilter *imf, const struct sockaddr_in *psin)
804{
805	struct ip_msource	 find;
806	struct ip_msource	*ims;
807	struct in_msource	*lims;
808
809	/* key is host byte order */
810	find.ims_haddr = ntohl(psin->sin_addr.s_addr);
811	ims = RB_FIND(ip_msource_tree, &imf->imf_sources, &find);
812	if (ims == NULL)
813		return (ENOENT);
814	lims = (struct in_msource *)ims;
815	lims->imsl_st[1] = MCAST_UNDEFINED;
816	return (0);
817}
818
819/*
820 * Revert socket-layer filter set deltas at t1 to t0 state.
821 */
822static void
823imf_rollback(struct in_mfilter *imf)
824{
825	struct ip_msource	*ims, *tims;
826	struct in_msource	*lims;
827
828	RB_FOREACH_SAFE(ims, ip_msource_tree, &imf->imf_sources, tims) {
829		lims = (struct in_msource *)ims;
830		if (lims->imsl_st[0] == lims->imsl_st[1]) {
831			/* no change at t1 */
832			continue;
833		} else if (lims->imsl_st[0] != MCAST_UNDEFINED) {
834			/* revert change to existing source at t1 */
835			lims->imsl_st[1] = lims->imsl_st[0];
836		} else {
837			/* revert source added t1 */
838			CTR2(KTR_IGMPV3, "%s: free ims %p", __func__, ims);
839			RB_REMOVE(ip_msource_tree, &imf->imf_sources, ims);
840			free(ims, M_INMFILTER);
841			imf->imf_nsrc--;
842		}
843	}
844	imf->imf_st[1] = imf->imf_st[0];
845}
846
847/*
848 * Mark socket-layer filter set as INCLUDE {} at t1.
849 */
850static void
851imf_leave(struct in_mfilter *imf)
852{
853	struct ip_msource	*ims;
854	struct in_msource	*lims;
855
856	RB_FOREACH(ims, ip_msource_tree, &imf->imf_sources) {
857		lims = (struct in_msource *)ims;
858		lims->imsl_st[1] = MCAST_UNDEFINED;
859	}
860	imf->imf_st[1] = MCAST_INCLUDE;
861}
862
863/*
864 * Mark socket-layer filter set deltas as committed.
865 */
866static void
867imf_commit(struct in_mfilter *imf)
868{
869	struct ip_msource	*ims;
870	struct in_msource	*lims;
871
872	RB_FOREACH(ims, ip_msource_tree, &imf->imf_sources) {
873		lims = (struct in_msource *)ims;
874		lims->imsl_st[0] = lims->imsl_st[1];
875	}
876	imf->imf_st[0] = imf->imf_st[1];
877}
878
879/*
880 * Reap unreferenced sources from socket-layer filter set.
881 */
882static void
883imf_reap(struct in_mfilter *imf)
884{
885	struct ip_msource	*ims, *tims;
886	struct in_msource	*lims;
887
888	RB_FOREACH_SAFE(ims, ip_msource_tree, &imf->imf_sources, tims) {
889		lims = (struct in_msource *)ims;
890		if ((lims->imsl_st[0] == MCAST_UNDEFINED) &&
891		    (lims->imsl_st[1] == MCAST_UNDEFINED)) {
892			CTR2(KTR_IGMPV3, "%s: free lims %p", __func__, ims);
893			RB_REMOVE(ip_msource_tree, &imf->imf_sources, ims);
894			free(ims, M_INMFILTER);
895			imf->imf_nsrc--;
896		}
897	}
898}
899
900/*
901 * Purge socket-layer filter set.
902 */
903static void
904imf_purge(struct in_mfilter *imf)
905{
906	struct ip_msource	*ims, *tims;
907
908	RB_FOREACH_SAFE(ims, ip_msource_tree, &imf->imf_sources, tims) {
909		CTR2(KTR_IGMPV3, "%s: free ims %p", __func__, ims);
910		RB_REMOVE(ip_msource_tree, &imf->imf_sources, ims);
911		free(ims, M_INMFILTER);
912		imf->imf_nsrc--;
913	}
914	imf->imf_st[0] = imf->imf_st[1] = MCAST_UNDEFINED;
915	KASSERT(RB_EMPTY(&imf->imf_sources),
916	    ("%s: imf_sources not empty", __func__));
917}
918
919/*
920 * Look up a source filter entry for a multicast group.
921 *
922 * inm is the group descriptor to work with.
923 * haddr is the host-byte-order IPv4 address to look up.
924 * noalloc may be non-zero to suppress allocation of sources.
925 * *pims will be set to the address of the retrieved or allocated source.
926 *
927 * SMPng: NOTE: may be called with locks held.
928 * Return 0 if successful, otherwise return a non-zero error code.
929 */
930static int
931inm_get_source(struct in_multi *inm, const in_addr_t haddr,
932    const int noalloc, struct ip_msource **pims)
933{
934	struct ip_msource	 find;
935	struct ip_msource	*ims, *nims;
936
937	find.ims_haddr = haddr;
938	ims = RB_FIND(ip_msource_tree, &inm->inm_srcs, &find);
939	if (ims == NULL && !noalloc) {
940		if (inm->inm_nsrc == in_mcast_maxgrpsrc)
941			return (ENOSPC);
942		nims = malloc(sizeof(struct ip_msource), M_IPMSOURCE,
943		    M_NOWAIT | M_ZERO);
944		if (nims == NULL)
945			return (ENOMEM);
946		nims->ims_haddr = haddr;
947		RB_INSERT(ip_msource_tree, &inm->inm_srcs, nims);
948		++inm->inm_nsrc;
949		ims = nims;
950#ifdef KTR
951		CTR3(KTR_IGMPV3, "%s: allocated 0x%08x as %p", __func__,
952		    haddr, ims);
953#endif
954	}
955
956	*pims = ims;
957	return (0);
958}
959
960/*
961 * Merge socket-layer source into IGMP-layer source.
962 * If rollback is non-zero, perform the inverse of the merge.
963 */
964static void
965ims_merge(struct ip_msource *ims, const struct in_msource *lims,
966    const int rollback)
967{
968	int n = rollback ? -1 : 1;
969
970	if (lims->imsl_st[0] == MCAST_EXCLUDE) {
971		CTR3(KTR_IGMPV3, "%s: t1 ex -= %d on 0x%08x",
972		    __func__, n, ims->ims_haddr);
973		ims->ims_st[1].ex -= n;
974	} else if (lims->imsl_st[0] == MCAST_INCLUDE) {
975		CTR3(KTR_IGMPV3, "%s: t1 in -= %d on 0x%08x",
976		    __func__, n, ims->ims_haddr);
977		ims->ims_st[1].in -= n;
978	}
979
980	if (lims->imsl_st[1] == MCAST_EXCLUDE) {
981		CTR3(KTR_IGMPV3, "%s: t1 ex += %d on 0x%08x",
982		    __func__, n, ims->ims_haddr);
983		ims->ims_st[1].ex += n;
984	} else if (lims->imsl_st[1] == MCAST_INCLUDE) {
985		CTR3(KTR_IGMPV3, "%s: t1 in += %d on 0x%08x",
986		    __func__, n, ims->ims_haddr);
987		ims->ims_st[1].in += n;
988	}
989}
990
991/*
992 * Atomically update the global in_multi state, when a membership's
993 * filter list is being updated in any way.
994 *
995 * imf is the per-inpcb-membership group filter pointer.
996 * A fake imf may be passed for in-kernel consumers.
997 *
998 * XXX This is a candidate for a set-symmetric-difference style loop
999 * which would eliminate the repeated lookup from root of ims nodes,
1000 * as they share the same key space.
1001 *
1002 * If any error occurred this function will back out of refcounts
1003 * and return a non-zero value.
1004 */
1005static int
1006inm_merge(struct in_multi *inm, /*const*/ struct in_mfilter *imf)
1007{
1008	struct ip_msource	*ims, *nims;
1009	struct in_msource	*lims;
1010	int			 schanged, error;
1011	int			 nsrc0, nsrc1;
1012
1013	schanged = 0;
1014	error = 0;
1015	nsrc1 = nsrc0 = 0;
1016	IN_MULTI_LIST_LOCK_ASSERT();
1017
1018	/*
1019	 * Update the source filters first, as this may fail.
1020	 * Maintain count of in-mode filters at t0, t1. These are
1021	 * used to work out if we transition into ASM mode or not.
1022	 * Maintain a count of source filters whose state was
1023	 * actually modified by this operation.
1024	 */
1025	RB_FOREACH(ims, ip_msource_tree, &imf->imf_sources) {
1026		lims = (struct in_msource *)ims;
1027		if (lims->imsl_st[0] == imf->imf_st[0]) nsrc0++;
1028		if (lims->imsl_st[1] == imf->imf_st[1]) nsrc1++;
1029		if (lims->imsl_st[0] == lims->imsl_st[1]) continue;
1030		error = inm_get_source(inm, lims->ims_haddr, 0, &nims);
1031		++schanged;
1032		if (error)
1033			break;
1034		ims_merge(nims, lims, 0);
1035	}
1036	if (error) {
1037		struct ip_msource *bims;
1038
1039		RB_FOREACH_REVERSE_FROM(ims, ip_msource_tree, nims) {
1040			lims = (struct in_msource *)ims;
1041			if (lims->imsl_st[0] == lims->imsl_st[1])
1042				continue;
1043			(void)inm_get_source(inm, lims->ims_haddr, 1, &bims);
1044			if (bims == NULL)
1045				continue;
1046			ims_merge(bims, lims, 1);
1047		}
1048		goto out_reap;
1049	}
1050
1051	CTR3(KTR_IGMPV3, "%s: imf filters in-mode: %d at t0, %d at t1",
1052	    __func__, nsrc0, nsrc1);
1053
1054	/* Handle transition between INCLUDE {n} and INCLUDE {} on socket. */
1055	if (imf->imf_st[0] == imf->imf_st[1] &&
1056	    imf->imf_st[1] == MCAST_INCLUDE) {
1057		if (nsrc1 == 0) {
1058			CTR1(KTR_IGMPV3, "%s: --in on inm at t1", __func__);
1059			--inm->inm_st[1].iss_in;
1060		}
1061	}
1062
1063	/* Handle filter mode transition on socket. */
1064	if (imf->imf_st[0] != imf->imf_st[1]) {
1065		CTR3(KTR_IGMPV3, "%s: imf transition %d to %d",
1066		    __func__, imf->imf_st[0], imf->imf_st[1]);
1067
1068		if (imf->imf_st[0] == MCAST_EXCLUDE) {
1069			CTR1(KTR_IGMPV3, "%s: --ex on inm at t1", __func__);
1070			--inm->inm_st[1].iss_ex;
1071		} else if (imf->imf_st[0] == MCAST_INCLUDE) {
1072			CTR1(KTR_IGMPV3, "%s: --in on inm at t1", __func__);
1073			--inm->inm_st[1].iss_in;
1074		}
1075
1076		if (imf->imf_st[1] == MCAST_EXCLUDE) {
1077			CTR1(KTR_IGMPV3, "%s: ex++ on inm at t1", __func__);
1078			inm->inm_st[1].iss_ex++;
1079		} else if (imf->imf_st[1] == MCAST_INCLUDE && nsrc1 > 0) {
1080			CTR1(KTR_IGMPV3, "%s: in++ on inm at t1", __func__);
1081			inm->inm_st[1].iss_in++;
1082		}
1083	}
1084
1085	/*
1086	 * Track inm filter state in terms of listener counts.
1087	 * If there are any exclusive listeners, stack-wide
1088	 * membership is exclusive.
1089	 * Otherwise, if only inclusive listeners, stack-wide is inclusive.
1090	 * If no listeners remain, state is undefined at t1,
1091	 * and the IGMP lifecycle for this group should finish.
1092	 */
1093	if (inm->inm_st[1].iss_ex > 0) {
1094		CTR1(KTR_IGMPV3, "%s: transition to EX", __func__);
1095		inm->inm_st[1].iss_fmode = MCAST_EXCLUDE;
1096	} else if (inm->inm_st[1].iss_in > 0) {
1097		CTR1(KTR_IGMPV3, "%s: transition to IN", __func__);
1098		inm->inm_st[1].iss_fmode = MCAST_INCLUDE;
1099	} else {
1100		CTR1(KTR_IGMPV3, "%s: transition to UNDEF", __func__);
1101		inm->inm_st[1].iss_fmode = MCAST_UNDEFINED;
1102	}
1103
1104	/* Decrement ASM listener count on transition out of ASM mode. */
1105	if (imf->imf_st[0] == MCAST_EXCLUDE && nsrc0 == 0) {
1106		if ((imf->imf_st[1] != MCAST_EXCLUDE) ||
1107		    (imf->imf_st[1] == MCAST_EXCLUDE && nsrc1 > 0)) {
1108			CTR1(KTR_IGMPV3, "%s: --asm on inm at t1", __func__);
1109			--inm->inm_st[1].iss_asm;
1110		}
1111	}
1112
1113	/* Increment ASM listener count on transition to ASM mode. */
1114	if (imf->imf_st[1] == MCAST_EXCLUDE && nsrc1 == 0) {
1115		CTR1(KTR_IGMPV3, "%s: asm++ on inm at t1", __func__);
1116		inm->inm_st[1].iss_asm++;
1117	}
1118
1119	CTR3(KTR_IGMPV3, "%s: merged imf %p to inm %p", __func__, imf, inm);
1120	inm_print(inm);
1121
1122out_reap:
1123	if (schanged > 0) {
1124		CTR1(KTR_IGMPV3, "%s: sources changed; reaping", __func__);
1125		inm_reap(inm);
1126	}
1127	return (error);
1128}
1129
1130/*
1131 * Mark an in_multi's filter set deltas as committed.
1132 * Called by IGMP after a state change has been enqueued.
1133 */
1134void
1135inm_commit(struct in_multi *inm)
1136{
1137	struct ip_msource	*ims;
1138
1139	CTR2(KTR_IGMPV3, "%s: commit inm %p", __func__, inm);
1140	CTR1(KTR_IGMPV3, "%s: pre commit:", __func__);
1141	inm_print(inm);
1142
1143	RB_FOREACH(ims, ip_msource_tree, &inm->inm_srcs) {
1144		ims->ims_st[0] = ims->ims_st[1];
1145	}
1146	inm->inm_st[0] = inm->inm_st[1];
1147}
1148
1149/*
1150 * Reap unreferenced nodes from an in_multi's filter set.
1151 */
1152static void
1153inm_reap(struct in_multi *inm)
1154{
1155	struct ip_msource	*ims, *tims;
1156
1157	RB_FOREACH_SAFE(ims, ip_msource_tree, &inm->inm_srcs, tims) {
1158		if (ims->ims_st[0].ex > 0 || ims->ims_st[0].in > 0 ||
1159		    ims->ims_st[1].ex > 0 || ims->ims_st[1].in > 0 ||
1160		    ims->ims_stp != 0)
1161			continue;
1162		CTR2(KTR_IGMPV3, "%s: free ims %p", __func__, ims);
1163		RB_REMOVE(ip_msource_tree, &inm->inm_srcs, ims);
1164		free(ims, M_IPMSOURCE);
1165		inm->inm_nsrc--;
1166	}
1167}
1168
1169/*
1170 * Purge all source nodes from an in_multi's filter set.
1171 */
1172static void
1173inm_purge(struct in_multi *inm)
1174{
1175	struct ip_msource	*ims, *tims;
1176
1177	RB_FOREACH_SAFE(ims, ip_msource_tree, &inm->inm_srcs, tims) {
1178		CTR2(KTR_IGMPV3, "%s: free ims %p", __func__, ims);
1179		RB_REMOVE(ip_msource_tree, &inm->inm_srcs, ims);
1180		free(ims, M_IPMSOURCE);
1181		inm->inm_nsrc--;
1182	}
1183	mbufq_drain(&inm->inm_scq);
1184}
1185
1186/*
1187 * Join a multicast group; unlocked entry point.
1188 *
1189 * SMPng: XXX: in_joingroup() is called from in_control().  Fortunately,
1190 * ifp is unlikely to have been detached at this point, so we assume
1191 * it's OK to recurse.
1192 */
1193int
1194in_joingroup(struct ifnet *ifp, const struct in_addr *gina,
1195    /*const*/ struct in_mfilter *imf, struct in_multi **pinm)
1196{
1197	int error;
1198
1199	IN_MULTI_LOCK();
1200	error = in_joingroup_locked(ifp, gina, imf, pinm);
1201	IN_MULTI_UNLOCK();
1202
1203	return (error);
1204}
1205
1206/*
1207 * Join a multicast group; real entry point.
1208 *
1209 * Only preserves atomicity at inm level.
1210 * NOTE: imf argument cannot be const due to sys/tree.h limitations.
1211 *
1212 * If the IGMP downcall fails, the group is not joined, and an error
1213 * code is returned.
1214 */
1215int
1216in_joingroup_locked(struct ifnet *ifp, const struct in_addr *gina,
1217    /*const*/ struct in_mfilter *imf, struct in_multi **pinm)
1218{
1219	struct in_mfilter	 timf;
1220	struct in_multi		*inm;
1221	int			 error;
1222
1223	IN_MULTI_LOCK_ASSERT();
1224	IN_MULTI_LIST_UNLOCK_ASSERT();
1225
1226	CTR4(KTR_IGMPV3, "%s: join 0x%08x on %p(%s))", __func__,
1227	    ntohl(gina->s_addr), ifp, ifp->if_xname);
1228
1229	error = 0;
1230	inm = NULL;
1231
1232	/*
1233	 * If no imf was specified (i.e. kernel consumer),
1234	 * fake one up and assume it is an ASM join.
1235	 */
1236	if (imf == NULL) {
1237		imf_init(&timf, MCAST_UNDEFINED, MCAST_EXCLUDE);
1238		imf = &timf;
1239	}
1240
1241	error = in_getmulti(ifp, gina, &inm);
1242	if (error) {
1243		CTR1(KTR_IGMPV3, "%s: in_getmulti() failure", __func__);
1244		return (error);
1245	}
1246	IN_MULTI_LIST_LOCK();
1247	CTR1(KTR_IGMPV3, "%s: merge inm state", __func__);
1248	error = inm_merge(inm, imf);
1249	if (error) {
1250		CTR1(KTR_IGMPV3, "%s: failed to merge inm state", __func__);
1251		goto out_inm_release;
1252	}
1253
1254	CTR1(KTR_IGMPV3, "%s: doing igmp downcall", __func__);
1255	error = igmp_change_state(inm);
1256	if (error) {
1257		CTR1(KTR_IGMPV3, "%s: failed to update source", __func__);
1258		goto out_inm_release;
1259	}
1260
1261 out_inm_release:
1262	if (error) {
1263		CTR2(KTR_IGMPV3, "%s: dropping ref on %p", __func__, inm);
1264		IF_ADDR_WLOCK(ifp);
1265		inm_release_deferred(inm);
1266		IF_ADDR_WUNLOCK(ifp);
1267	} else {
1268		*pinm = inm;
1269	}
1270	IN_MULTI_LIST_UNLOCK();
1271
1272	return (error);
1273}
1274
1275/*
1276 * Leave a multicast group; unlocked entry point.
1277 */
1278int
1279in_leavegroup(struct in_multi *inm, /*const*/ struct in_mfilter *imf)
1280{
1281	int error;
1282
1283	IN_MULTI_LOCK();
1284	error = in_leavegroup_locked(inm, imf);
1285	IN_MULTI_UNLOCK();
1286
1287	return (error);
1288}
1289
1290/*
1291 * Leave a multicast group; real entry point.
1292 * All source filters will be expunged.
1293 *
1294 * Only preserves atomicity at inm level.
1295 *
1296 * Holding the write lock for the INP which contains imf
1297 * is highly advisable. We can't assert for it as imf does not
1298 * contain a back-pointer to the owning inp.
1299 *
1300 * Note: This is not the same as inm_release(*) as this function also
1301 * makes a state change downcall into IGMP.
1302 */
1303int
1304in_leavegroup_locked(struct in_multi *inm, /*const*/ struct in_mfilter *imf)
1305{
1306	struct in_mfilter	 timf;
1307	int			 error;
1308
1309	IN_MULTI_LOCK_ASSERT();
1310	IN_MULTI_LIST_UNLOCK_ASSERT();
1311
1312	error = 0;
1313
1314	CTR5(KTR_IGMPV3, "%s: leave inm %p, 0x%08x/%s, imf %p", __func__,
1315	    inm, ntohl(inm->inm_addr.s_addr),
1316	    (inm_is_ifp_detached(inm) ? "null" : inm->inm_ifp->if_xname),
1317	    imf);
1318
1319	/*
1320	 * If no imf was specified (i.e. kernel consumer),
1321	 * fake one up and assume it is an ASM join.
1322	 */
1323	if (imf == NULL) {
1324		imf_init(&timf, MCAST_EXCLUDE, MCAST_UNDEFINED);
1325		imf = &timf;
1326	}
1327
1328	/*
1329	 * Begin state merge transaction at IGMP layer.
1330	 *
1331	 * As this particular invocation should not cause any memory
1332	 * to be allocated, and there is no opportunity to roll back
1333	 * the transaction, it MUST NOT fail.
1334	 */
1335	CTR1(KTR_IGMPV3, "%s: merge inm state", __func__);
1336	IN_MULTI_LIST_LOCK();
1337	error = inm_merge(inm, imf);
1338	KASSERT(error == 0, ("%s: failed to merge inm state", __func__));
1339
1340	CTR1(KTR_IGMPV3, "%s: doing igmp downcall", __func__);
1341	CURVNET_SET(inm->inm_ifp->if_vnet);
1342	error = igmp_change_state(inm);
1343	IF_ADDR_WLOCK(inm->inm_ifp);
1344	inm_release_deferred(inm);
1345	IF_ADDR_WUNLOCK(inm->inm_ifp);
1346	IN_MULTI_LIST_UNLOCK();
1347	CURVNET_RESTORE();
1348	if (error)
1349		CTR1(KTR_IGMPV3, "%s: failed igmp downcall", __func__);
1350
1351	CTR2(KTR_IGMPV3, "%s: dropping ref on %p", __func__, inm);
1352
1353	return (error);
1354}
1355
1356/*#ifndef BURN_BRIDGES*/
1357
1358/*
1359 * Block or unblock an ASM multicast source on an inpcb.
1360 * This implements the delta-based API described in RFC 3678.
1361 *
1362 * The delta-based API applies only to exclusive-mode memberships.
1363 * An IGMP downcall will be performed.
1364 *
1365 * Return 0 if successful, otherwise return an appropriate error code.
1366 */
1367static int
1368inp_block_unblock_source(struct inpcb *inp, struct sockopt *sopt)
1369{
1370	struct epoch_tracker		 et;
1371	struct group_source_req		 gsr;
1372	sockunion_t			*gsa, *ssa;
1373	struct ifnet			*ifp;
1374	struct in_mfilter		*imf;
1375	struct ip_moptions		*imo;
1376	struct in_msource		*ims;
1377	struct in_multi			*inm;
1378	uint16_t			 fmode;
1379	int				 error, doblock;
1380
1381	ifp = NULL;
1382	error = 0;
1383	doblock = 0;
1384
1385	memset(&gsr, 0, sizeof(struct group_source_req));
1386	gsa = (sockunion_t *)&gsr.gsr_group;
1387	ssa = (sockunion_t *)&gsr.gsr_source;
1388
1389	switch (sopt->sopt_name) {
1390	case IP_BLOCK_SOURCE:
1391	case IP_UNBLOCK_SOURCE: {
1392		struct ip_mreq_source	 mreqs;
1393
1394		error = sooptcopyin(sopt, &mreqs,
1395		    sizeof(struct ip_mreq_source),
1396		    sizeof(struct ip_mreq_source));
1397		if (error)
1398			return (error);
1399
1400		gsa->sin.sin_family = AF_INET;
1401		gsa->sin.sin_len = sizeof(struct sockaddr_in);
1402		gsa->sin.sin_addr = mreqs.imr_multiaddr;
1403
1404		ssa->sin.sin_family = AF_INET;
1405		ssa->sin.sin_len = sizeof(struct sockaddr_in);
1406		ssa->sin.sin_addr = mreqs.imr_sourceaddr;
1407
1408		if (!in_nullhost(mreqs.imr_interface)) {
1409			NET_EPOCH_ENTER(et);
1410			INADDR_TO_IFP(mreqs.imr_interface, ifp);
1411			/* XXXGL: ifref? */
1412			NET_EPOCH_EXIT(et);
1413		}
1414		if (sopt->sopt_name == IP_BLOCK_SOURCE)
1415			doblock = 1;
1416
1417		CTR3(KTR_IGMPV3, "%s: imr_interface = 0x%08x, ifp = %p",
1418		    __func__, ntohl(mreqs.imr_interface.s_addr), ifp);
1419		break;
1420	    }
1421
1422	case MCAST_BLOCK_SOURCE:
1423	case MCAST_UNBLOCK_SOURCE:
1424		error = sooptcopyin(sopt, &gsr,
1425		    sizeof(struct group_source_req),
1426		    sizeof(struct group_source_req));
1427		if (error)
1428			return (error);
1429
1430		if (gsa->sin.sin_family != AF_INET ||
1431		    gsa->sin.sin_len != sizeof(struct sockaddr_in))
1432			return (EINVAL);
1433
1434		if (ssa->sin.sin_family != AF_INET ||
1435		    ssa->sin.sin_len != sizeof(struct sockaddr_in))
1436			return (EINVAL);
1437
1438		NET_EPOCH_ENTER(et);
1439		ifp = ifnet_byindex(gsr.gsr_interface);
1440		NET_EPOCH_EXIT(et);
1441		if (ifp == NULL)
1442			return (EADDRNOTAVAIL);
1443
1444		if (sopt->sopt_name == MCAST_BLOCK_SOURCE)
1445			doblock = 1;
1446		break;
1447
1448	default:
1449		CTR2(KTR_IGMPV3, "%s: unknown sopt_name %d",
1450		    __func__, sopt->sopt_name);
1451		return (EOPNOTSUPP);
1452		break;
1453	}
1454
1455	if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
1456		return (EINVAL);
1457
1458	IN_MULTI_LOCK();
1459
1460	/*
1461	 * Check if we are actually a member of this group.
1462	 */
1463	imo = inp_findmoptions(inp);
1464	imf = imo_match_group(imo, ifp, &gsa->sa);
1465	if (imf == NULL) {
1466		error = EADDRNOTAVAIL;
1467		goto out_inp_locked;
1468	}
1469	inm = imf->imf_inm;
1470
1471	/*
1472	 * Attempting to use the delta-based API on an
1473	 * non exclusive-mode membership is an error.
1474	 */
1475	fmode = imf->imf_st[0];
1476	if (fmode != MCAST_EXCLUDE) {
1477		error = EINVAL;
1478		goto out_inp_locked;
1479	}
1480
1481	/*
1482	 * Deal with error cases up-front:
1483	 *  Asked to block, but already blocked; or
1484	 *  Asked to unblock, but nothing to unblock.
1485	 * If adding a new block entry, allocate it.
1486	 */
1487	ims = imo_match_source(imf, &ssa->sa);
1488	if ((ims != NULL && doblock) || (ims == NULL && !doblock)) {
1489		CTR3(KTR_IGMPV3, "%s: source 0x%08x %spresent", __func__,
1490		    ntohl(ssa->sin.sin_addr.s_addr), doblock ? "" : "not ");
1491		error = EADDRNOTAVAIL;
1492		goto out_inp_locked;
1493	}
1494
1495	INP_WLOCK_ASSERT(inp);
1496
1497	/*
1498	 * Begin state merge transaction at socket layer.
1499	 */
1500	if (doblock) {
1501		CTR2(KTR_IGMPV3, "%s: %s source", __func__, "block");
1502		ims = imf_graft(imf, fmode, &ssa->sin);
1503		if (ims == NULL)
1504			error = ENOMEM;
1505	} else {
1506		CTR2(KTR_IGMPV3, "%s: %s source", __func__, "allow");
1507		error = imf_prune(imf, &ssa->sin);
1508	}
1509
1510	if (error) {
1511		CTR1(KTR_IGMPV3, "%s: merge imf state failed", __func__);
1512		goto out_imf_rollback;
1513	}
1514
1515	/*
1516	 * Begin state merge transaction at IGMP layer.
1517	 */
1518	CTR1(KTR_IGMPV3, "%s: merge inm state", __func__);
1519	IN_MULTI_LIST_LOCK();
1520	error = inm_merge(inm, imf);
1521	if (error) {
1522		CTR1(KTR_IGMPV3, "%s: failed to merge inm state", __func__);
1523		IN_MULTI_LIST_UNLOCK();
1524		goto out_imf_rollback;
1525	}
1526
1527	CTR1(KTR_IGMPV3, "%s: doing igmp downcall", __func__);
1528	error = igmp_change_state(inm);
1529	IN_MULTI_LIST_UNLOCK();
1530	if (error)
1531		CTR1(KTR_IGMPV3, "%s: failed igmp downcall", __func__);
1532
1533out_imf_rollback:
1534	if (error)
1535		imf_rollback(imf);
1536	else
1537		imf_commit(imf);
1538
1539	imf_reap(imf);
1540
1541out_inp_locked:
1542	INP_WUNLOCK(inp);
1543	IN_MULTI_UNLOCK();
1544	return (error);
1545}
1546
1547/*
1548 * Given an inpcb, return its multicast options structure pointer.  Accepts
1549 * an unlocked inpcb pointer, but will return it locked.  May sleep.
1550 *
1551 * SMPng: NOTE: Returns with the INP write lock held.
1552 */
1553static struct ip_moptions *
1554inp_findmoptions(struct inpcb *inp)
1555{
1556	struct ip_moptions	 *imo;
1557
1558	INP_WLOCK(inp);
1559	if (inp->inp_moptions != NULL)
1560		return (inp->inp_moptions);
1561
1562	INP_WUNLOCK(inp);
1563
1564	imo = malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK);
1565
1566	imo->imo_multicast_ifp = NULL;
1567	imo->imo_multicast_addr.s_addr = INADDR_ANY;
1568	imo->imo_multicast_vif = -1;
1569	imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1570	imo->imo_multicast_loop = in_mcast_loop;
1571	STAILQ_INIT(&imo->imo_head);
1572
1573	INP_WLOCK(inp);
1574	if (inp->inp_moptions != NULL) {
1575		free(imo, M_IPMOPTS);
1576		return (inp->inp_moptions);
1577	}
1578	inp->inp_moptions = imo;
1579	return (imo);
1580}
1581
1582void
1583inp_freemoptions(struct ip_moptions *imo)
1584{
1585	struct in_mfilter *imf;
1586	struct in_multi *inm;
1587	struct ifnet *ifp;
1588
1589	if (imo == NULL)
1590		return;
1591
1592	while ((imf = ip_mfilter_first(&imo->imo_head)) != NULL) {
1593		ip_mfilter_remove(&imo->imo_head, imf);
1594
1595		imf_leave(imf);
1596		if ((inm = imf->imf_inm) != NULL) {
1597			if ((ifp = inm->inm_ifp) != NULL) {
1598				CURVNET_SET(ifp->if_vnet);
1599				(void)in_leavegroup(inm, imf);
1600				CURVNET_RESTORE();
1601			} else {
1602				(void)in_leavegroup(inm, imf);
1603			}
1604		}
1605		ip_mfilter_free(imf);
1606	}
1607	free(imo, M_IPMOPTS);
1608}
1609
1610/*
1611 * Atomically get source filters on a socket for an IPv4 multicast group.
1612 * Called with INP lock held; returns with lock released.
1613 */
1614static int
1615inp_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
1616{
1617	struct epoch_tracker	 et;
1618	struct __msfilterreq	 msfr;
1619	sockunion_t		*gsa;
1620	struct ifnet		*ifp;
1621	struct ip_moptions	*imo;
1622	struct in_mfilter	*imf;
1623	struct ip_msource	*ims;
1624	struct in_msource	*lims;
1625	struct sockaddr_in	*psin;
1626	struct sockaddr_storage	*ptss;
1627	struct sockaddr_storage	*tss;
1628	int			 error;
1629	size_t			 nsrcs, ncsrcs;
1630
1631	INP_WLOCK_ASSERT(inp);
1632
1633	imo = inp->inp_moptions;
1634	KASSERT(imo != NULL, ("%s: null ip_moptions", __func__));
1635
1636	INP_WUNLOCK(inp);
1637
1638	error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
1639	    sizeof(struct __msfilterreq));
1640	if (error)
1641		return (error);
1642
1643	NET_EPOCH_ENTER(et);
1644	ifp = ifnet_byindex(msfr.msfr_ifindex);
1645	NET_EPOCH_EXIT(et);	/* XXXGL: unsafe ifnet pointer left */
1646	if (ifp == NULL)
1647		return (EINVAL);
1648
1649	INP_WLOCK(inp);
1650
1651	/*
1652	 * Lookup group on the socket.
1653	 */
1654	gsa = (sockunion_t *)&msfr.msfr_group;
1655	imf = imo_match_group(imo, ifp, &gsa->sa);
1656	if (imf == NULL) {
1657		INP_WUNLOCK(inp);
1658		return (EADDRNOTAVAIL);
1659	}
1660
1661	/*
1662	 * Ignore memberships which are in limbo.
1663	 */
1664	if (imf->imf_st[1] == MCAST_UNDEFINED) {
1665		INP_WUNLOCK(inp);
1666		return (EAGAIN);
1667	}
1668	msfr.msfr_fmode = imf->imf_st[1];
1669
1670	/*
1671	 * If the user specified a buffer, copy out the source filter
1672	 * entries to userland gracefully.
1673	 * We only copy out the number of entries which userland
1674	 * has asked for, but we always tell userland how big the
1675	 * buffer really needs to be.
1676	 */
1677	if (msfr.msfr_nsrcs > in_mcast_maxsocksrc)
1678		msfr.msfr_nsrcs = in_mcast_maxsocksrc;
1679	tss = NULL;
1680	if (msfr.msfr_srcs != NULL && msfr.msfr_nsrcs > 0) {
1681		tss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
1682		    M_TEMP, M_NOWAIT | M_ZERO);
1683		if (tss == NULL) {
1684			INP_WUNLOCK(inp);
1685			return (ENOBUFS);
1686		}
1687	}
1688
1689	/*
1690	 * Count number of sources in-mode at t0.
1691	 * If buffer space exists and remains, copy out source entries.
1692	 */
1693	nsrcs = msfr.msfr_nsrcs;
1694	ncsrcs = 0;
1695	ptss = tss;
1696	RB_FOREACH(ims, ip_msource_tree, &imf->imf_sources) {
1697		lims = (struct in_msource *)ims;
1698		if (lims->imsl_st[0] == MCAST_UNDEFINED ||
1699		    lims->imsl_st[0] != imf->imf_st[0])
1700			continue;
1701		++ncsrcs;
1702		if (tss != NULL && nsrcs > 0) {
1703			psin = (struct sockaddr_in *)ptss;
1704			psin->sin_family = AF_INET;
1705			psin->sin_len = sizeof(struct sockaddr_in);
1706			psin->sin_addr.s_addr = htonl(lims->ims_haddr);
1707			psin->sin_port = 0;
1708			++ptss;
1709			--nsrcs;
1710		}
1711	}
1712
1713	INP_WUNLOCK(inp);
1714
1715	if (tss != NULL) {
1716		error = copyout(tss, msfr.msfr_srcs,
1717		    sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
1718		free(tss, M_TEMP);
1719		if (error)
1720			return (error);
1721	}
1722
1723	msfr.msfr_nsrcs = ncsrcs;
1724	error = sooptcopyout(sopt, &msfr, sizeof(struct __msfilterreq));
1725
1726	return (error);
1727}
1728
1729/*
1730 * Return the IP multicast options in response to user getsockopt().
1731 */
1732int
1733inp_getmoptions(struct inpcb *inp, struct sockopt *sopt)
1734{
1735	struct ip_mreqn		 mreqn;
1736	struct ip_moptions	*imo;
1737	struct ifnet		*ifp;
1738	struct in_ifaddr	*ia;
1739	int			 error, optval;
1740	u_char			 coptval;
1741
1742	INP_WLOCK(inp);
1743	imo = inp->inp_moptions;
1744	/* If socket is neither of type SOCK_RAW or SOCK_DGRAM reject it. */
1745	if (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
1746	    inp->inp_socket->so_proto->pr_type != SOCK_DGRAM) {
1747		INP_WUNLOCK(inp);
1748		return (EOPNOTSUPP);
1749	}
1750
1751	error = 0;
1752	switch (sopt->sopt_name) {
1753	case IP_MULTICAST_VIF:
1754		if (imo != NULL)
1755			optval = imo->imo_multicast_vif;
1756		else
1757			optval = -1;
1758		INP_WUNLOCK(inp);
1759		error = sooptcopyout(sopt, &optval, sizeof(int));
1760		break;
1761
1762	case IP_MULTICAST_IF:
1763		memset(&mreqn, 0, sizeof(struct ip_mreqn));
1764		if (imo != NULL) {
1765			ifp = imo->imo_multicast_ifp;
1766			if (!in_nullhost(imo->imo_multicast_addr)) {
1767				mreqn.imr_address = imo->imo_multicast_addr;
1768			} else if (ifp != NULL) {
1769				struct epoch_tracker et;
1770
1771				mreqn.imr_ifindex = ifp->if_index;
1772				NET_EPOCH_ENTER(et);
1773				IFP_TO_IA(ifp, ia);
1774				if (ia != NULL)
1775					mreqn.imr_address =
1776					    IA_SIN(ia)->sin_addr;
1777				NET_EPOCH_EXIT(et);
1778			}
1779		}
1780		INP_WUNLOCK(inp);
1781		if (sopt->sopt_valsize == sizeof(struct ip_mreqn)) {
1782			error = sooptcopyout(sopt, &mreqn,
1783			    sizeof(struct ip_mreqn));
1784		} else {
1785			error = sooptcopyout(sopt, &mreqn.imr_address,
1786			    sizeof(struct in_addr));
1787		}
1788		break;
1789
1790	case IP_MULTICAST_TTL:
1791		if (imo == NULL)
1792			optval = coptval = IP_DEFAULT_MULTICAST_TTL;
1793		else
1794			optval = coptval = imo->imo_multicast_ttl;
1795		INP_WUNLOCK(inp);
1796		if (sopt->sopt_valsize == sizeof(u_char))
1797			error = sooptcopyout(sopt, &coptval, sizeof(u_char));
1798		else
1799			error = sooptcopyout(sopt, &optval, sizeof(int));
1800		break;
1801
1802	case IP_MULTICAST_LOOP:
1803		if (imo == NULL)
1804			optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
1805		else
1806			optval = coptval = imo->imo_multicast_loop;
1807		INP_WUNLOCK(inp);
1808		if (sopt->sopt_valsize == sizeof(u_char))
1809			error = sooptcopyout(sopt, &coptval, sizeof(u_char));
1810		else
1811			error = sooptcopyout(sopt, &optval, sizeof(int));
1812		break;
1813
1814	case IP_MSFILTER:
1815		if (imo == NULL) {
1816			error = EADDRNOTAVAIL;
1817			INP_WUNLOCK(inp);
1818		} else {
1819			error = inp_get_source_filters(inp, sopt);
1820		}
1821		break;
1822
1823	default:
1824		INP_WUNLOCK(inp);
1825		error = ENOPROTOOPT;
1826		break;
1827	}
1828
1829	INP_UNLOCK_ASSERT(inp);
1830
1831	return (error);
1832}
1833
1834/*
1835 * Look up the ifnet to use for a multicast group membership,
1836 * given the IPv4 address of an interface, and the IPv4 group address.
1837 *
1838 * This routine exists to support legacy multicast applications
1839 * which do not understand that multicast memberships are scoped to
1840 * specific physical links in the networking stack, or which need
1841 * to join link-scope groups before IPv4 addresses are configured.
1842 *
1843 * Use this socket's current FIB number for any required FIB lookup.
1844 * If ina is INADDR_ANY, look up the group address in the unicast FIB,
1845 * and use its ifp; usually, this points to the default next-hop.
1846 *
1847 * If the FIB lookup fails, attempt to use the first non-loopback
1848 * interface with multicast capability in the system as a
1849 * last resort. The legacy IPv4 ASM API requires that we do
1850 * this in order to allow groups to be joined when the routing
1851 * table has not yet been populated during boot.
1852 *
1853 * Returns NULL if no ifp could be found, otherwise return referenced ifp.
1854 *
1855 * FUTURE: Implement IPv4 source-address selection.
1856 */
1857static struct ifnet *
1858inp_lookup_mcast_ifp(const struct inpcb *inp,
1859    const struct sockaddr_in *gsin, const struct in_addr ina)
1860{
1861	struct ifnet *ifp;
1862	struct nhop_object *nh;
1863
1864	NET_EPOCH_ASSERT();
1865	KASSERT(inp != NULL, ("%s: inp must not be NULL", __func__));
1866	KASSERT(gsin->sin_family == AF_INET, ("%s: not AF_INET", __func__));
1867	KASSERT(IN_MULTICAST(ntohl(gsin->sin_addr.s_addr)),
1868	    ("%s: not multicast", __func__));
1869
1870	ifp = NULL;
1871	if (!in_nullhost(ina)) {
1872		INADDR_TO_IFP(ina, ifp);
1873		if (ifp != NULL)
1874			if_ref(ifp);
1875	} else {
1876		nh = fib4_lookup(inp->inp_inc.inc_fibnum, gsin->sin_addr, 0, NHR_NONE, 0);
1877		if (nh != NULL) {
1878			ifp = nh->nh_ifp;
1879			if_ref(ifp);
1880		} else {
1881			struct in_ifaddr *ia;
1882			struct ifnet *mifp;
1883
1884			mifp = NULL;
1885			CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1886				mifp = ia->ia_ifp;
1887				if (!(mifp->if_flags & IFF_LOOPBACK) &&
1888				     (mifp->if_flags & IFF_MULTICAST)) {
1889					ifp = mifp;
1890					if_ref(ifp);
1891					break;
1892				}
1893			}
1894		}
1895	}
1896
1897	return (ifp);
1898}
1899
1900/*
1901 * Join an IPv4 multicast group, possibly with a source.
1902 */
1903static int
1904inp_join_group(struct inpcb *inp, struct sockopt *sopt)
1905{
1906	struct group_source_req		 gsr;
1907	sockunion_t			*gsa, *ssa;
1908	struct ifnet			*ifp;
1909	struct in_mfilter		*imf;
1910	struct ip_moptions		*imo;
1911	struct in_multi			*inm;
1912	struct in_msource		*lims;
1913	struct epoch_tracker		 et;
1914	int				 error, is_new;
1915
1916	ifp = NULL;
1917	lims = NULL;
1918	error = 0;
1919
1920	memset(&gsr, 0, sizeof(struct group_source_req));
1921	gsa = (sockunion_t *)&gsr.gsr_group;
1922	gsa->ss.ss_family = AF_UNSPEC;
1923	ssa = (sockunion_t *)&gsr.gsr_source;
1924	ssa->ss.ss_family = AF_UNSPEC;
1925
1926	switch (sopt->sopt_name) {
1927	case IP_ADD_MEMBERSHIP: {
1928		struct ip_mreqn mreqn;
1929
1930		if (sopt->sopt_valsize == sizeof(struct ip_mreqn))
1931			error = sooptcopyin(sopt, &mreqn,
1932			    sizeof(struct ip_mreqn), sizeof(struct ip_mreqn));
1933		else
1934			error = sooptcopyin(sopt, &mreqn,
1935			    sizeof(struct ip_mreq), sizeof(struct ip_mreq));
1936		if (error)
1937			return (error);
1938
1939		gsa->sin.sin_family = AF_INET;
1940		gsa->sin.sin_len = sizeof(struct sockaddr_in);
1941		gsa->sin.sin_addr = mreqn.imr_multiaddr;
1942		if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
1943			return (EINVAL);
1944
1945		NET_EPOCH_ENTER(et);
1946		if (sopt->sopt_valsize == sizeof(struct ip_mreqn) &&
1947		    mreqn.imr_ifindex != 0)
1948			ifp = ifnet_byindex_ref(mreqn.imr_ifindex);
1949		else
1950			ifp = inp_lookup_mcast_ifp(inp, &gsa->sin,
1951			    mreqn.imr_address);
1952		NET_EPOCH_EXIT(et);
1953		break;
1954	}
1955	case IP_ADD_SOURCE_MEMBERSHIP: {
1956		struct ip_mreq_source	 mreqs;
1957
1958		error = sooptcopyin(sopt, &mreqs, sizeof(struct ip_mreq_source),
1959			    sizeof(struct ip_mreq_source));
1960		if (error)
1961			return (error);
1962
1963		gsa->sin.sin_family = ssa->sin.sin_family = AF_INET;
1964		gsa->sin.sin_len = ssa->sin.sin_len =
1965		    sizeof(struct sockaddr_in);
1966
1967		gsa->sin.sin_addr = mreqs.imr_multiaddr;
1968		if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
1969			return (EINVAL);
1970
1971		ssa->sin.sin_addr = mreqs.imr_sourceaddr;
1972
1973		NET_EPOCH_ENTER(et);
1974		ifp = inp_lookup_mcast_ifp(inp, &gsa->sin,
1975		    mreqs.imr_interface);
1976		NET_EPOCH_EXIT(et);
1977		CTR3(KTR_IGMPV3, "%s: imr_interface = 0x%08x, ifp = %p",
1978		    __func__, ntohl(mreqs.imr_interface.s_addr), ifp);
1979		break;
1980	}
1981
1982	case MCAST_JOIN_GROUP:
1983	case MCAST_JOIN_SOURCE_GROUP:
1984		if (sopt->sopt_name == MCAST_JOIN_GROUP) {
1985			error = sooptcopyin(sopt, &gsr,
1986			    sizeof(struct group_req),
1987			    sizeof(struct group_req));
1988		} else if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
1989			error = sooptcopyin(sopt, &gsr,
1990			    sizeof(struct group_source_req),
1991			    sizeof(struct group_source_req));
1992		}
1993		if (error)
1994			return (error);
1995
1996		if (gsa->sin.sin_family != AF_INET ||
1997		    gsa->sin.sin_len != sizeof(struct sockaddr_in))
1998			return (EINVAL);
1999
2000		/*
2001		 * Overwrite the port field if present, as the sockaddr
2002		 * being copied in may be matched with a binary comparison.
2003		 */
2004		gsa->sin.sin_port = 0;
2005		if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
2006			if (ssa->sin.sin_family != AF_INET ||
2007			    ssa->sin.sin_len != sizeof(struct sockaddr_in))
2008				return (EINVAL);
2009			ssa->sin.sin_port = 0;
2010		}
2011
2012		if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
2013			return (EINVAL);
2014
2015		NET_EPOCH_ENTER(et);
2016		ifp = ifnet_byindex_ref(gsr.gsr_interface);
2017		NET_EPOCH_EXIT(et);
2018		if (ifp == NULL)
2019			return (EADDRNOTAVAIL);
2020		break;
2021
2022	default:
2023		CTR2(KTR_IGMPV3, "%s: unknown sopt_name %d",
2024		    __func__, sopt->sopt_name);
2025		return (EOPNOTSUPP);
2026		break;
2027	}
2028
2029	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
2030		if (ifp != NULL)
2031			if_rele(ifp);
2032		return (EADDRNOTAVAIL);
2033	}
2034
2035	IN_MULTI_LOCK();
2036
2037	/*
2038	 * Find the membership in the membership list.
2039	 */
2040	imo = inp_findmoptions(inp);
2041	imf = imo_match_group(imo, ifp, &gsa->sa);
2042	if (imf == NULL) {
2043		is_new = 1;
2044		inm = NULL;
2045
2046		if (ip_mfilter_count(&imo->imo_head) >= IP_MAX_MEMBERSHIPS) {
2047			error = ENOMEM;
2048			goto out_inp_locked;
2049		}
2050	} else {
2051		is_new = 0;
2052		inm = imf->imf_inm;
2053
2054		if (ssa->ss.ss_family != AF_UNSPEC) {
2055			/*
2056			 * MCAST_JOIN_SOURCE_GROUP on an exclusive membership
2057			 * is an error. On an existing inclusive membership,
2058			 * it just adds the source to the filter list.
2059			 */
2060			if (imf->imf_st[1] != MCAST_INCLUDE) {
2061				error = EINVAL;
2062				goto out_inp_locked;
2063			}
2064			/*
2065			 * Throw out duplicates.
2066			 *
2067			 * XXX FIXME: This makes a naive assumption that
2068			 * even if entries exist for *ssa in this imf,
2069			 * they will be rejected as dupes, even if they
2070			 * are not valid in the current mode (in-mode).
2071			 *
2072			 * in_msource is transactioned just as for anything
2073			 * else in SSM -- but note naive use of inm_graft()
2074			 * below for allocating new filter entries.
2075			 *
2076			 * This is only an issue if someone mixes the
2077			 * full-state SSM API with the delta-based API,
2078			 * which is discouraged in the relevant RFCs.
2079			 */
2080			lims = imo_match_source(imf, &ssa->sa);
2081			if (lims != NULL /*&&
2082			    lims->imsl_st[1] == MCAST_INCLUDE*/) {
2083				error = EADDRNOTAVAIL;
2084				goto out_inp_locked;
2085			}
2086		} else {
2087			/*
2088			 * MCAST_JOIN_GROUP on an existing exclusive
2089			 * membership is an error; return EADDRINUSE
2090			 * to preserve 4.4BSD API idempotence, and
2091			 * avoid tedious detour to code below.
2092			 * NOTE: This is bending RFC 3678 a bit.
2093			 *
2094			 * On an existing inclusive membership, this is also
2095			 * an error; if you want to change filter mode,
2096			 * you must use the userland API setsourcefilter().
2097			 * XXX We don't reject this for imf in UNDEFINED
2098			 * state at t1, because allocation of a filter
2099			 * is atomic with allocation of a membership.
2100			 */
2101			error = EINVAL;
2102			if (imf->imf_st[1] == MCAST_EXCLUDE)
2103				error = EADDRINUSE;
2104			goto out_inp_locked;
2105		}
2106	}
2107
2108	/*
2109	 * Begin state merge transaction at socket layer.
2110	 */
2111	INP_WLOCK_ASSERT(inp);
2112
2113	/*
2114	 * Graft new source into filter list for this inpcb's
2115	 * membership of the group. The in_multi may not have
2116	 * been allocated yet if this is a new membership, however,
2117	 * the in_mfilter slot will be allocated and must be initialized.
2118	 *
2119	 * Note: Grafting of exclusive mode filters doesn't happen
2120	 * in this path.
2121	 * XXX: Should check for non-NULL lims (node exists but may
2122	 * not be in-mode) for interop with full-state API.
2123	 */
2124	if (ssa->ss.ss_family != AF_UNSPEC) {
2125		/* Membership starts in IN mode */
2126		if (is_new) {
2127			CTR1(KTR_IGMPV3, "%s: new join w/source", __func__);
2128			imf = ip_mfilter_alloc(M_NOWAIT, MCAST_UNDEFINED, MCAST_INCLUDE);
2129			if (imf == NULL) {
2130				error = ENOMEM;
2131				goto out_inp_locked;
2132			}
2133		} else {
2134			CTR2(KTR_IGMPV3, "%s: %s source", __func__, "allow");
2135		}
2136		lims = imf_graft(imf, MCAST_INCLUDE, &ssa->sin);
2137		if (lims == NULL) {
2138			CTR1(KTR_IGMPV3, "%s: merge imf state failed",
2139			    __func__);
2140			error = ENOMEM;
2141			goto out_inp_locked;
2142		}
2143	} else {
2144		/* No address specified; Membership starts in EX mode */
2145		if (is_new) {
2146			CTR1(KTR_IGMPV3, "%s: new join w/o source", __func__);
2147			imf = ip_mfilter_alloc(M_NOWAIT, MCAST_UNDEFINED, MCAST_EXCLUDE);
2148			if (imf == NULL) {
2149				error = ENOMEM;
2150				goto out_inp_locked;
2151			}
2152		}
2153	}
2154
2155	/*
2156	 * Begin state merge transaction at IGMP layer.
2157	 */
2158	if (is_new) {
2159		in_pcbref(inp);
2160		INP_WUNLOCK(inp);
2161
2162		error = in_joingroup_locked(ifp, &gsa->sin.sin_addr, imf,
2163		    &imf->imf_inm);
2164
2165		INP_WLOCK(inp);
2166		if (in_pcbrele_wlocked(inp)) {
2167			error = ENXIO;
2168			goto out_inp_unlocked;
2169		}
2170		if (error) {
2171                        CTR1(KTR_IGMPV3, "%s: in_joingroup_locked failed",
2172                            __func__);
2173			goto out_inp_locked;
2174		}
2175		/*
2176		 * NOTE: Refcount from in_joingroup_locked()
2177		 * is protecting membership.
2178		 */
2179		ip_mfilter_insert(&imo->imo_head, imf);
2180	} else {
2181		CTR1(KTR_IGMPV3, "%s: merge inm state", __func__);
2182		IN_MULTI_LIST_LOCK();
2183		error = inm_merge(inm, imf);
2184		if (error) {
2185			CTR1(KTR_IGMPV3, "%s: failed to merge inm state",
2186				 __func__);
2187			IN_MULTI_LIST_UNLOCK();
2188			imf_rollback(imf);
2189			imf_reap(imf);
2190			goto out_inp_locked;
2191		}
2192		CTR1(KTR_IGMPV3, "%s: doing igmp downcall", __func__);
2193		error = igmp_change_state(inm);
2194		IN_MULTI_LIST_UNLOCK();
2195		if (error) {
2196			CTR1(KTR_IGMPV3, "%s: failed igmp downcall",
2197			    __func__);
2198			imf_rollback(imf);
2199			imf_reap(imf);
2200			goto out_inp_locked;
2201		}
2202	}
2203
2204	imf_commit(imf);
2205	imf = NULL;
2206
2207out_inp_locked:
2208	INP_WUNLOCK(inp);
2209out_inp_unlocked:
2210	IN_MULTI_UNLOCK();
2211
2212	if (is_new && imf) {
2213		if (imf->imf_inm != NULL) {
2214			IN_MULTI_LIST_LOCK();
2215			IF_ADDR_WLOCK(ifp);
2216			inm_release_deferred(imf->imf_inm);
2217			IF_ADDR_WUNLOCK(ifp);
2218			IN_MULTI_LIST_UNLOCK();
2219		}
2220		ip_mfilter_free(imf);
2221	}
2222	if_rele(ifp);
2223	return (error);
2224}
2225
2226/*
2227 * Leave an IPv4 multicast group on an inpcb, possibly with a source.
2228 */
2229static int
2230inp_leave_group(struct inpcb *inp, struct sockopt *sopt)
2231{
2232	struct epoch_tracker		 et;
2233	struct group_source_req		 gsr;
2234	struct ip_mreq_source		 mreqs;
2235	sockunion_t			*gsa, *ssa;
2236	struct ifnet			*ifp;
2237	struct in_mfilter		*imf;
2238	struct ip_moptions		*imo;
2239	struct in_msource		*ims;
2240	struct in_multi			*inm;
2241	int				 error;
2242	bool				 is_final;
2243
2244	ifp = NULL;
2245	error = 0;
2246	is_final = true;
2247
2248	memset(&gsr, 0, sizeof(struct group_source_req));
2249	gsa = (sockunion_t *)&gsr.gsr_group;
2250	gsa->ss.ss_family = AF_UNSPEC;
2251	ssa = (sockunion_t *)&gsr.gsr_source;
2252	ssa->ss.ss_family = AF_UNSPEC;
2253
2254	switch (sopt->sopt_name) {
2255	case IP_DROP_MEMBERSHIP:
2256	case IP_DROP_SOURCE_MEMBERSHIP:
2257		if (sopt->sopt_name == IP_DROP_MEMBERSHIP) {
2258			error = sooptcopyin(sopt, &mreqs,
2259			    sizeof(struct ip_mreq),
2260			    sizeof(struct ip_mreq));
2261			/*
2262			 * Swap interface and sourceaddr arguments,
2263			 * as ip_mreq and ip_mreq_source are laid
2264			 * out differently.
2265			 */
2266			mreqs.imr_interface = mreqs.imr_sourceaddr;
2267			mreqs.imr_sourceaddr.s_addr = INADDR_ANY;
2268		} else if (sopt->sopt_name == IP_DROP_SOURCE_MEMBERSHIP) {
2269			error = sooptcopyin(sopt, &mreqs,
2270			    sizeof(struct ip_mreq_source),
2271			    sizeof(struct ip_mreq_source));
2272		}
2273		if (error)
2274			return (error);
2275
2276		gsa->sin.sin_family = AF_INET;
2277		gsa->sin.sin_len = sizeof(struct sockaddr_in);
2278		gsa->sin.sin_addr = mreqs.imr_multiaddr;
2279
2280		if (sopt->sopt_name == IP_DROP_SOURCE_MEMBERSHIP) {
2281			ssa->sin.sin_family = AF_INET;
2282			ssa->sin.sin_len = sizeof(struct sockaddr_in);
2283			ssa->sin.sin_addr = mreqs.imr_sourceaddr;
2284		}
2285
2286		/*
2287		 * Attempt to look up hinted ifp from interface address.
2288		 * Fallthrough with null ifp iff lookup fails, to
2289		 * preserve 4.4BSD mcast API idempotence.
2290		 * XXX NOTE WELL: The RFC 3678 API is preferred because
2291		 * using an IPv4 address as a key is racy.
2292		 */
2293		if (!in_nullhost(mreqs.imr_interface)) {
2294			NET_EPOCH_ENTER(et);
2295			INADDR_TO_IFP(mreqs.imr_interface, ifp);
2296			/* XXXGL ifref? */
2297			NET_EPOCH_EXIT(et);
2298		}
2299		CTR3(KTR_IGMPV3, "%s: imr_interface = 0x%08x, ifp = %p",
2300		    __func__, ntohl(mreqs.imr_interface.s_addr), ifp);
2301
2302		break;
2303
2304	case MCAST_LEAVE_GROUP:
2305	case MCAST_LEAVE_SOURCE_GROUP:
2306		if (sopt->sopt_name == MCAST_LEAVE_GROUP) {
2307			error = sooptcopyin(sopt, &gsr,
2308			    sizeof(struct group_req),
2309			    sizeof(struct group_req));
2310		} else if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
2311			error = sooptcopyin(sopt, &gsr,
2312			    sizeof(struct group_source_req),
2313			    sizeof(struct group_source_req));
2314		}
2315		if (error)
2316			return (error);
2317
2318		if (gsa->sin.sin_family != AF_INET ||
2319		    gsa->sin.sin_len != sizeof(struct sockaddr_in))
2320			return (EINVAL);
2321
2322		if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
2323			if (ssa->sin.sin_family != AF_INET ||
2324			    ssa->sin.sin_len != sizeof(struct sockaddr_in))
2325				return (EINVAL);
2326		}
2327
2328		NET_EPOCH_ENTER(et);
2329		ifp = ifnet_byindex(gsr.gsr_interface);
2330		NET_EPOCH_EXIT(et);	/* XXXGL: unsafe ifp */
2331		if (ifp == NULL)
2332			return (EADDRNOTAVAIL);
2333		break;
2334
2335	default:
2336		CTR2(KTR_IGMPV3, "%s: unknown sopt_name %d",
2337		    __func__, sopt->sopt_name);
2338		return (EOPNOTSUPP);
2339		break;
2340	}
2341
2342	if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
2343		return (EINVAL);
2344
2345	IN_MULTI_LOCK();
2346
2347	/*
2348	 * Find the membership in the membership list.
2349	 */
2350	imo = inp_findmoptions(inp);
2351	imf = imo_match_group(imo, ifp, &gsa->sa);
2352	if (imf == NULL) {
2353		error = EADDRNOTAVAIL;
2354		goto out_inp_locked;
2355	}
2356	inm = imf->imf_inm;
2357
2358	if (ssa->ss.ss_family != AF_UNSPEC)
2359		is_final = false;
2360
2361	/*
2362	 * Begin state merge transaction at socket layer.
2363	 */
2364	INP_WLOCK_ASSERT(inp);
2365
2366	/*
2367	 * If we were instructed only to leave a given source, do so.
2368	 * MCAST_LEAVE_SOURCE_GROUP is only valid for inclusive memberships.
2369	 */
2370	if (is_final) {
2371		ip_mfilter_remove(&imo->imo_head, imf);
2372		imf_leave(imf);
2373
2374		/*
2375		 * Give up the multicast address record to which
2376		 * the membership points.
2377		 */
2378		(void) in_leavegroup_locked(imf->imf_inm, imf);
2379	} else {
2380		if (imf->imf_st[0] == MCAST_EXCLUDE) {
2381			error = EADDRNOTAVAIL;
2382			goto out_inp_locked;
2383		}
2384		ims = imo_match_source(imf, &ssa->sa);
2385		if (ims == NULL) {
2386			CTR3(KTR_IGMPV3, "%s: source 0x%08x %spresent",
2387			    __func__, ntohl(ssa->sin.sin_addr.s_addr), "not ");
2388			error = EADDRNOTAVAIL;
2389			goto out_inp_locked;
2390		}
2391		CTR2(KTR_IGMPV3, "%s: %s source", __func__, "block");
2392		error = imf_prune(imf, &ssa->sin);
2393		if (error) {
2394			CTR1(KTR_IGMPV3, "%s: merge imf state failed",
2395			    __func__);
2396			goto out_inp_locked;
2397		}
2398	}
2399
2400	/*
2401	 * Begin state merge transaction at IGMP layer.
2402	 */
2403	if (!is_final) {
2404		CTR1(KTR_IGMPV3, "%s: merge inm state", __func__);
2405		IN_MULTI_LIST_LOCK();
2406		error = inm_merge(inm, imf);
2407		if (error) {
2408			CTR1(KTR_IGMPV3, "%s: failed to merge inm state",
2409			    __func__);
2410			IN_MULTI_LIST_UNLOCK();
2411			imf_rollback(imf);
2412			imf_reap(imf);
2413			goto out_inp_locked;
2414		}
2415
2416		CTR1(KTR_IGMPV3, "%s: doing igmp downcall", __func__);
2417		error = igmp_change_state(inm);
2418		IN_MULTI_LIST_UNLOCK();
2419		if (error) {
2420			CTR1(KTR_IGMPV3, "%s: failed igmp downcall",
2421			    __func__);
2422			imf_rollback(imf);
2423			imf_reap(imf);
2424			goto out_inp_locked;
2425		}
2426	}
2427	imf_commit(imf);
2428	imf_reap(imf);
2429
2430out_inp_locked:
2431	INP_WUNLOCK(inp);
2432
2433	if (is_final && imf)
2434		ip_mfilter_free(imf);
2435
2436	IN_MULTI_UNLOCK();
2437	return (error);
2438}
2439
2440/*
2441 * Select the interface for transmitting IPv4 multicast datagrams.
2442 *
2443 * Either an instance of struct in_addr or an instance of struct ip_mreqn
2444 * may be passed to this socket option. An address of INADDR_ANY or an
2445 * interface index of 0 is used to remove a previous selection.
2446 * When no interface is selected, one is chosen for every send.
2447 */
2448static int
2449inp_set_multicast_if(struct inpcb *inp, struct sockopt *sopt)
2450{
2451	struct in_addr		 addr;
2452	struct ip_mreqn		 mreqn;
2453	struct ifnet		*ifp;
2454	struct ip_moptions	*imo;
2455	int			 error;
2456
2457	if (sopt->sopt_valsize == sizeof(struct ip_mreqn)) {
2458		/*
2459		 * An interface index was specified using the
2460		 * Linux-derived ip_mreqn structure.
2461		 */
2462		error = sooptcopyin(sopt, &mreqn, sizeof(struct ip_mreqn),
2463		    sizeof(struct ip_mreqn));
2464		if (error)
2465			return (error);
2466
2467		if (mreqn.imr_ifindex < 0)
2468			return (EINVAL);
2469
2470		if (mreqn.imr_ifindex == 0) {
2471			ifp = NULL;
2472		} else {
2473			struct epoch_tracker et;
2474
2475			NET_EPOCH_ENTER(et);
2476			ifp = ifnet_byindex(mreqn.imr_ifindex);
2477			NET_EPOCH_EXIT(et);	/* XXXGL: unsafe ifp */
2478			if (ifp == NULL)
2479				return (EADDRNOTAVAIL);
2480		}
2481	} else {
2482		/*
2483		 * An interface was specified by IPv4 address.
2484		 * This is the traditional BSD usage.
2485		 */
2486		error = sooptcopyin(sopt, &addr, sizeof(struct in_addr),
2487		    sizeof(struct in_addr));
2488		if (error)
2489			return (error);
2490		if (in_nullhost(addr)) {
2491			ifp = NULL;
2492		} else {
2493			struct epoch_tracker et;
2494
2495			NET_EPOCH_ENTER(et);
2496			INADDR_TO_IFP(addr, ifp);
2497			/* XXXGL ifref? */
2498			NET_EPOCH_EXIT(et);
2499			if (ifp == NULL)
2500				return (EADDRNOTAVAIL);
2501		}
2502		CTR3(KTR_IGMPV3, "%s: ifp = %p, addr = 0x%08x", __func__, ifp,
2503		    ntohl(addr.s_addr));
2504	}
2505
2506	/* Reject interfaces which do not support multicast. */
2507	if (ifp != NULL && (ifp->if_flags & IFF_MULTICAST) == 0)
2508		return (EOPNOTSUPP);
2509
2510	imo = inp_findmoptions(inp);
2511	imo->imo_multicast_ifp = ifp;
2512	imo->imo_multicast_addr.s_addr = INADDR_ANY;
2513	INP_WUNLOCK(inp);
2514
2515	return (0);
2516}
2517
2518/*
2519 * Atomically set source filters on a socket for an IPv4 multicast group.
2520 */
2521static int
2522inp_set_source_filters(struct inpcb *inp, struct sockopt *sopt)
2523{
2524	struct epoch_tracker	 et;
2525	struct __msfilterreq	 msfr;
2526	sockunion_t		*gsa;
2527	struct ifnet		*ifp;
2528	struct in_mfilter	*imf;
2529	struct ip_moptions	*imo;
2530	struct in_multi		*inm;
2531	int			 error;
2532
2533	error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
2534	    sizeof(struct __msfilterreq));
2535	if (error)
2536		return (error);
2537
2538	if (msfr.msfr_nsrcs > in_mcast_maxsocksrc)
2539		return (ENOBUFS);
2540
2541	if ((msfr.msfr_fmode != MCAST_EXCLUDE &&
2542	     msfr.msfr_fmode != MCAST_INCLUDE))
2543		return (EINVAL);
2544
2545	if (msfr.msfr_group.ss_family != AF_INET ||
2546	    msfr.msfr_group.ss_len != sizeof(struct sockaddr_in))
2547		return (EINVAL);
2548
2549	gsa = (sockunion_t *)&msfr.msfr_group;
2550	if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
2551		return (EINVAL);
2552
2553	gsa->sin.sin_port = 0;	/* ignore port */
2554
2555	NET_EPOCH_ENTER(et);
2556	ifp = ifnet_byindex(msfr.msfr_ifindex);
2557	NET_EPOCH_EXIT(et);	/* XXXGL: unsafe ifp */
2558	if (ifp == NULL)
2559		return (EADDRNOTAVAIL);
2560
2561	IN_MULTI_LOCK();
2562
2563	/*
2564	 * Take the INP write lock.
2565	 * Check if this socket is a member of this group.
2566	 */
2567	imo = inp_findmoptions(inp);
2568	imf = imo_match_group(imo, ifp, &gsa->sa);
2569	if (imf == NULL) {
2570		error = EADDRNOTAVAIL;
2571		goto out_inp_locked;
2572	}
2573	inm = imf->imf_inm;
2574
2575	/*
2576	 * Begin state merge transaction at socket layer.
2577	 */
2578	INP_WLOCK_ASSERT(inp);
2579
2580	imf->imf_st[1] = msfr.msfr_fmode;
2581
2582	/*
2583	 * Apply any new source filters, if present.
2584	 * Make a copy of the user-space source vector so
2585	 * that we may copy them with a single copyin. This
2586	 * allows us to deal with page faults up-front.
2587	 */
2588	if (msfr.msfr_nsrcs > 0) {
2589		struct in_msource	*lims;
2590		struct sockaddr_in	*psin;
2591		struct sockaddr_storage	*kss, *pkss;
2592		int			 i;
2593
2594		INP_WUNLOCK(inp);
2595
2596		CTR2(KTR_IGMPV3, "%s: loading %lu source list entries",
2597		    __func__, (unsigned long)msfr.msfr_nsrcs);
2598		kss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
2599		    M_TEMP, M_WAITOK);
2600		error = copyin(msfr.msfr_srcs, kss,
2601		    sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
2602		if (error) {
2603			free(kss, M_TEMP);
2604			return (error);
2605		}
2606
2607		INP_WLOCK(inp);
2608
2609		/*
2610		 * Mark all source filters as UNDEFINED at t1.
2611		 * Restore new group filter mode, as imf_leave()
2612		 * will set it to INCLUDE.
2613		 */
2614		imf_leave(imf);
2615		imf->imf_st[1] = msfr.msfr_fmode;
2616
2617		/*
2618		 * Update socket layer filters at t1, lazy-allocating
2619		 * new entries. This saves a bunch of memory at the
2620		 * cost of one RB_FIND() per source entry; duplicate
2621		 * entries in the msfr_nsrcs vector are ignored.
2622		 * If we encounter an error, rollback transaction.
2623		 *
2624		 * XXX This too could be replaced with a set-symmetric
2625		 * difference like loop to avoid walking from root
2626		 * every time, as the key space is common.
2627		 */
2628		for (i = 0, pkss = kss; i < msfr.msfr_nsrcs; i++, pkss++) {
2629			psin = (struct sockaddr_in *)pkss;
2630			if (psin->sin_family != AF_INET) {
2631				error = EAFNOSUPPORT;
2632				break;
2633			}
2634			if (psin->sin_len != sizeof(struct sockaddr_in)) {
2635				error = EINVAL;
2636				break;
2637			}
2638			error = imf_get_source(imf, psin, &lims);
2639			if (error)
2640				break;
2641			lims->imsl_st[1] = imf->imf_st[1];
2642		}
2643		free(kss, M_TEMP);
2644	}
2645
2646	if (error)
2647		goto out_imf_rollback;
2648
2649	INP_WLOCK_ASSERT(inp);
2650
2651	/*
2652	 * Begin state merge transaction at IGMP layer.
2653	 */
2654	CTR1(KTR_IGMPV3, "%s: merge inm state", __func__);
2655	IN_MULTI_LIST_LOCK();
2656	error = inm_merge(inm, imf);
2657	if (error) {
2658		CTR1(KTR_IGMPV3, "%s: failed to merge inm state", __func__);
2659		IN_MULTI_LIST_UNLOCK();
2660		goto out_imf_rollback;
2661	}
2662
2663	CTR1(KTR_IGMPV3, "%s: doing igmp downcall", __func__);
2664	error = igmp_change_state(inm);
2665	IN_MULTI_LIST_UNLOCK();
2666	if (error)
2667		CTR1(KTR_IGMPV3, "%s: failed igmp downcall", __func__);
2668
2669out_imf_rollback:
2670	if (error)
2671		imf_rollback(imf);
2672	else
2673		imf_commit(imf);
2674
2675	imf_reap(imf);
2676
2677out_inp_locked:
2678	INP_WUNLOCK(inp);
2679	IN_MULTI_UNLOCK();
2680	return (error);
2681}
2682
2683/*
2684 * Set the IP multicast options in response to user setsockopt().
2685 *
2686 * Many of the socket options handled in this function duplicate the
2687 * functionality of socket options in the regular unicast API. However,
2688 * it is not possible to merge the duplicate code, because the idempotence
2689 * of the IPv4 multicast part of the BSD Sockets API must be preserved;
2690 * the effects of these options must be treated as separate and distinct.
2691 *
2692 * SMPng: XXX: Unlocked read of inp_socket believed OK.
2693 * FUTURE: The IP_MULTICAST_VIF option may be eliminated if MROUTING
2694 * is refactored to no longer use vifs.
2695 */
2696int
2697inp_setmoptions(struct inpcb *inp, struct sockopt *sopt)
2698{
2699	struct ip_moptions	*imo;
2700	int			 error;
2701
2702	error = 0;
2703
2704	/* If socket is neither of type SOCK_RAW or SOCK_DGRAM, reject it. */
2705	if (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
2706	     inp->inp_socket->so_proto->pr_type != SOCK_DGRAM)
2707		return (EOPNOTSUPP);
2708
2709	switch (sopt->sopt_name) {
2710	case IP_MULTICAST_VIF: {
2711		int vifi;
2712		/*
2713		 * Select a multicast VIF for transmission.
2714		 * Only useful if multicast forwarding is active.
2715		 */
2716		if (legal_vif_num == NULL) {
2717			error = EOPNOTSUPP;
2718			break;
2719		}
2720		error = sooptcopyin(sopt, &vifi, sizeof(int), sizeof(int));
2721		if (error)
2722			break;
2723		if (!legal_vif_num(vifi) && (vifi != -1)) {
2724			error = EINVAL;
2725			break;
2726		}
2727		imo = inp_findmoptions(inp);
2728		imo->imo_multicast_vif = vifi;
2729		INP_WUNLOCK(inp);
2730		break;
2731	}
2732
2733	case IP_MULTICAST_IF:
2734		error = inp_set_multicast_if(inp, sopt);
2735		break;
2736
2737	case IP_MULTICAST_TTL: {
2738		u_char ttl;
2739
2740		/*
2741		 * Set the IP time-to-live for outgoing multicast packets.
2742		 * The original multicast API required a char argument,
2743		 * which is inconsistent with the rest of the socket API.
2744		 * We allow either a char or an int.
2745		 */
2746		if (sopt->sopt_valsize == sizeof(u_char)) {
2747			error = sooptcopyin(sopt, &ttl, sizeof(u_char),
2748			    sizeof(u_char));
2749			if (error)
2750				break;
2751		} else {
2752			u_int ittl;
2753
2754			error = sooptcopyin(sopt, &ittl, sizeof(u_int),
2755			    sizeof(u_int));
2756			if (error)
2757				break;
2758			if (ittl > 255) {
2759				error = EINVAL;
2760				break;
2761			}
2762			ttl = (u_char)ittl;
2763		}
2764		imo = inp_findmoptions(inp);
2765		imo->imo_multicast_ttl = ttl;
2766		INP_WUNLOCK(inp);
2767		break;
2768	}
2769
2770	case IP_MULTICAST_LOOP: {
2771		u_char loop;
2772
2773		/*
2774		 * Set the loopback flag for outgoing multicast packets.
2775		 * Must be zero or one.  The original multicast API required a
2776		 * char argument, which is inconsistent with the rest
2777		 * of the socket API.  We allow either a char or an int.
2778		 */
2779		if (sopt->sopt_valsize == sizeof(u_char)) {
2780			error = sooptcopyin(sopt, &loop, sizeof(u_char),
2781			    sizeof(u_char));
2782			if (error)
2783				break;
2784		} else {
2785			u_int iloop;
2786
2787			error = sooptcopyin(sopt, &iloop, sizeof(u_int),
2788					    sizeof(u_int));
2789			if (error)
2790				break;
2791			loop = (u_char)iloop;
2792		}
2793		imo = inp_findmoptions(inp);
2794		imo->imo_multicast_loop = !!loop;
2795		INP_WUNLOCK(inp);
2796		break;
2797	}
2798
2799	case IP_ADD_MEMBERSHIP:
2800	case IP_ADD_SOURCE_MEMBERSHIP:
2801	case MCAST_JOIN_GROUP:
2802	case MCAST_JOIN_SOURCE_GROUP:
2803		error = inp_join_group(inp, sopt);
2804		break;
2805
2806	case IP_DROP_MEMBERSHIP:
2807	case IP_DROP_SOURCE_MEMBERSHIP:
2808	case MCAST_LEAVE_GROUP:
2809	case MCAST_LEAVE_SOURCE_GROUP:
2810		error = inp_leave_group(inp, sopt);
2811		break;
2812
2813	case IP_BLOCK_SOURCE:
2814	case IP_UNBLOCK_SOURCE:
2815	case MCAST_BLOCK_SOURCE:
2816	case MCAST_UNBLOCK_SOURCE:
2817		error = inp_block_unblock_source(inp, sopt);
2818		break;
2819
2820	case IP_MSFILTER:
2821		error = inp_set_source_filters(inp, sopt);
2822		break;
2823
2824	default:
2825		error = EOPNOTSUPP;
2826		break;
2827	}
2828
2829	INP_UNLOCK_ASSERT(inp);
2830
2831	return (error);
2832}
2833
2834/*
2835 * Expose IGMP's multicast filter mode and source list(s) to userland,
2836 * keyed by (ifindex, group).
2837 * The filter mode is written out as a uint32_t, followed by
2838 * 0..n of struct in_addr.
2839 * For use by ifmcstat(8).
2840 * SMPng: NOTE: unlocked read of ifindex space.
2841 */
2842static int
2843sysctl_ip_mcast_filters(SYSCTL_HANDLER_ARGS)
2844{
2845	struct in_addr			 src, group;
2846	struct epoch_tracker		 et;
2847	struct ifnet			*ifp;
2848	struct ifmultiaddr		*ifma;
2849	struct in_multi			*inm;
2850	struct ip_msource		*ims;
2851	int				*name;
2852	int				 retval;
2853	u_int				 namelen;
2854	uint32_t			 fmode, ifindex;
2855
2856	name = (int *)arg1;
2857	namelen = arg2;
2858
2859	if (req->newptr != NULL)
2860		return (EPERM);
2861
2862	if (namelen != 2)
2863		return (EINVAL);
2864
2865	group.s_addr = name[1];
2866	if (!IN_MULTICAST(ntohl(group.s_addr))) {
2867		CTR2(KTR_IGMPV3, "%s: group 0x%08x is not multicast",
2868		    __func__, ntohl(group.s_addr));
2869		return (EINVAL);
2870	}
2871
2872	ifindex = name[0];
2873	NET_EPOCH_ENTER(et);
2874	ifp = ifnet_byindex(ifindex);
2875	if (ifp == NULL) {
2876		NET_EPOCH_EXIT(et);
2877		CTR2(KTR_IGMPV3, "%s: no ifp for ifindex %u",
2878		    __func__, ifindex);
2879		return (ENOENT);
2880	}
2881
2882	retval = sysctl_wire_old_buffer(req,
2883	    sizeof(uint32_t) + (in_mcast_maxgrpsrc * sizeof(struct in_addr)));
2884	if (retval) {
2885		NET_EPOCH_EXIT(et);
2886		return (retval);
2887	}
2888
2889	IN_MULTI_LIST_LOCK();
2890
2891	CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
2892		inm = inm_ifmultiaddr_get_inm(ifma);
2893		if (inm == NULL)
2894			continue;
2895		if (!in_hosteq(inm->inm_addr, group))
2896			continue;
2897		fmode = inm->inm_st[1].iss_fmode;
2898		retval = SYSCTL_OUT(req, &fmode, sizeof(uint32_t));
2899		if (retval != 0)
2900			break;
2901		RB_FOREACH(ims, ip_msource_tree, &inm->inm_srcs) {
2902			CTR2(KTR_IGMPV3, "%s: visit node 0x%08x", __func__,
2903			    ims->ims_haddr);
2904			/*
2905			 * Only copy-out sources which are in-mode.
2906			 */
2907			if (fmode != ims_get_mode(inm, ims, 1)) {
2908				CTR1(KTR_IGMPV3, "%s: skip non-in-mode",
2909				    __func__);
2910				continue;
2911			}
2912			src.s_addr = htonl(ims->ims_haddr);
2913			retval = SYSCTL_OUT(req, &src, sizeof(struct in_addr));
2914			if (retval != 0)
2915				break;
2916		}
2917	}
2918
2919	IN_MULTI_LIST_UNLOCK();
2920	NET_EPOCH_EXIT(et);
2921
2922	return (retval);
2923}
2924
2925#if defined(KTR) && (KTR_COMPILE & KTR_IGMPV3)
2926
2927static const char *inm_modestrs[] = {
2928	[MCAST_UNDEFINED] = "un",
2929	[MCAST_INCLUDE] = "in",
2930	[MCAST_EXCLUDE] = "ex",
2931};
2932_Static_assert(MCAST_UNDEFINED == 0 &&
2933	       MCAST_EXCLUDE + 1 == nitems(inm_modestrs),
2934	       "inm_modestrs: no longer matches #defines");
2935
2936static const char *
2937inm_mode_str(const int mode)
2938{
2939
2940	if (mode >= MCAST_UNDEFINED && mode <= MCAST_EXCLUDE)
2941		return (inm_modestrs[mode]);
2942	return ("??");
2943}
2944
2945static const char *inm_statestrs[] = {
2946	[IGMP_NOT_MEMBER] = "not-member",
2947	[IGMP_SILENT_MEMBER] = "silent",
2948	[IGMP_REPORTING_MEMBER] = "reporting",
2949	[IGMP_IDLE_MEMBER] = "idle",
2950	[IGMP_LAZY_MEMBER] = "lazy",
2951	[IGMP_SLEEPING_MEMBER] = "sleeping",
2952	[IGMP_AWAKENING_MEMBER] = "awakening",
2953	[IGMP_G_QUERY_PENDING_MEMBER] = "query-pending",
2954	[IGMP_SG_QUERY_PENDING_MEMBER] = "sg-query-pending",
2955	[IGMP_LEAVING_MEMBER] = "leaving",
2956};
2957_Static_assert(IGMP_NOT_MEMBER == 0 &&
2958	       IGMP_LEAVING_MEMBER + 1 == nitems(inm_statestrs),
2959	       "inm_statetrs: no longer matches #defines");
2960
2961static const char *
2962inm_state_str(const int state)
2963{
2964
2965	if (state >= IGMP_NOT_MEMBER && state <= IGMP_LEAVING_MEMBER)
2966		return (inm_statestrs[state]);
2967	return ("??");
2968}
2969
2970/*
2971 * Dump an in_multi structure to the console.
2972 */
2973void
2974inm_print(const struct in_multi *inm)
2975{
2976	int t;
2977	char addrbuf[INET_ADDRSTRLEN];
2978
2979	if ((ktr_mask & KTR_IGMPV3) == 0)
2980		return;
2981
2982	printf("%s: --- begin inm %p ---\n", __func__, inm);
2983	printf("addr %s ifp %p(%s) ifma %p\n",
2984	    inet_ntoa_r(inm->inm_addr, addrbuf),
2985	    inm->inm_ifp,
2986	    inm->inm_ifp->if_xname,
2987	    inm->inm_ifma);
2988	printf("timer %u state %s refcount %u scq.len %u\n",
2989	    inm->inm_timer,
2990	    inm_state_str(inm->inm_state),
2991	    inm->inm_refcount,
2992	    inm->inm_scq.mq_len);
2993	printf("igi %p nsrc %lu sctimer %u scrv %u\n",
2994	    inm->inm_igi,
2995	    inm->inm_nsrc,
2996	    inm->inm_sctimer,
2997	    inm->inm_scrv);
2998	for (t = 0; t < 2; t++) {
2999		printf("t%d: fmode %s asm %u ex %u in %u rec %u\n", t,
3000		    inm_mode_str(inm->inm_st[t].iss_fmode),
3001		    inm->inm_st[t].iss_asm,
3002		    inm->inm_st[t].iss_ex,
3003		    inm->inm_st[t].iss_in,
3004		    inm->inm_st[t].iss_rec);
3005	}
3006	printf("%s: --- end inm %p ---\n", __func__, inm);
3007}
3008
3009#else /* !KTR || !(KTR_COMPILE & KTR_IGMPV3) */
3010
3011void
3012inm_print(const struct in_multi *inm)
3013{
3014
3015}
3016
3017#endif /* KTR && (KTR_COMPILE & KTR_IGMPV3) */
3018
3019RB_GENERATE(ip_msource_tree, ip_msource, ims_link, ip_msource_cmp);
3020