The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/in6_mcast.c

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    1 /*
    2  * Copyright (c) 2009 Bruce Simpson.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. The name of the author may not be used to endorse or promote
   14  *    products derived from this software without specific prior written
   15  *    permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 /*
   31  * IPv6 multicast socket, group, and socket option processing module.
   32  * Normative references: RFC 2292, RFC 3492, RFC 3542, RFC 3678, RFC 3810.
   33  */
   34 
   35 #include <sys/cdefs.h>
   36 __FBSDID("$FreeBSD$");
   37 
   38 #include "opt_inet6.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/kernel.h>
   43 #include <sys/malloc.h>
   44 #include <sys/mbuf.h>
   45 #include <sys/protosw.h>
   46 #include <sys/socket.h>
   47 #include <sys/socketvar.h>
   48 #include <sys/protosw.h>
   49 #include <sys/sysctl.h>
   50 #include <sys/priv.h>
   51 #include <sys/ktr.h>
   52 #include <sys/tree.h>
   53 
   54 #include <net/if.h>
   55 #include <net/if_dl.h>
   56 #include <net/route.h>
   57 #include <net/vnet.h>
   58 
   59 #include <netinet/in.h>
   60 #include <netinet/in_var.h>
   61 #include <netinet6/in6_var.h>
   62 #include <netinet/ip6.h>
   63 #include <netinet/icmp6.h>
   64 #include <netinet6/ip6_var.h>
   65 #include <netinet/in_pcb.h>
   66 #include <netinet/tcp_var.h>
   67 #include <netinet6/nd6.h>
   68 #include <netinet6/mld6_var.h>
   69 #include <netinet6/scope6_var.h>
   70 
   71 #ifndef KTR_MLD
   72 #define KTR_MLD KTR_INET6
   73 #endif
   74 
   75 #ifndef __SOCKUNION_DECLARED
   76 union sockunion {
   77         struct sockaddr_storage ss;
   78         struct sockaddr         sa;
   79         struct sockaddr_dl      sdl;
   80         struct sockaddr_in6     sin6;
   81 };
   82 typedef union sockunion sockunion_t;
   83 #define __SOCKUNION_DECLARED
   84 #endif /* __SOCKUNION_DECLARED */
   85 
   86 static MALLOC_DEFINE(M_IN6MFILTER, "in6_mfilter",
   87     "IPv6 multicast PCB-layer source filter");
   88 static MALLOC_DEFINE(M_IP6MADDR, "in6_multi", "IPv6 multicast group");
   89 static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "IPv6 multicast options");
   90 static MALLOC_DEFINE(M_IP6MSOURCE, "ip6_msource",
   91     "IPv6 multicast MLD-layer source filter");
   92 
   93 RB_GENERATE(ip6_msource_tree, ip6_msource, im6s_link, ip6_msource_cmp);
   94 
   95 /*
   96  * Locking:
   97  * - Lock order is: Giant, INP_WLOCK, IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
   98  * - The IF_ADDR_LOCK is implicitly taken by in6m_lookup() earlier, however
   99  *   it can be taken by code in net/if.c also.
  100  * - ip6_moptions and in6_mfilter are covered by the INP_WLOCK.
  101  *
  102  * struct in6_multi is covered by IN6_MULTI_LOCK. There isn't strictly
  103  * any need for in6_multi itself to be virtualized -- it is bound to an ifp
  104  * anyway no matter what happens.
  105  */
  106 struct mtx in6_multi_mtx;
  107 MTX_SYSINIT(in6_multi_mtx, &in6_multi_mtx, "in6_multi_mtx", MTX_DEF);
  108 
  109 static void     im6f_commit(struct in6_mfilter *);
  110 static int      im6f_get_source(struct in6_mfilter *imf,
  111                     const struct sockaddr_in6 *psin,
  112                     struct in6_msource **);
  113 static struct in6_msource *
  114                 im6f_graft(struct in6_mfilter *, const uint8_t,
  115                     const struct sockaddr_in6 *);
  116 static void     im6f_leave(struct in6_mfilter *);
  117 static int      im6f_prune(struct in6_mfilter *, const struct sockaddr_in6 *);
  118 static void     im6f_purge(struct in6_mfilter *);
  119 static void     im6f_rollback(struct in6_mfilter *);
  120 static void     im6f_reap(struct in6_mfilter *);
  121 static int      im6o_grow(struct ip6_moptions *);
  122 static size_t   im6o_match_group(const struct ip6_moptions *,
  123                     const struct ifnet *, const struct sockaddr *);
  124 static struct in6_msource *
  125                 im6o_match_source(const struct ip6_moptions *, const size_t,
  126                     const struct sockaddr *);
  127 static void     im6s_merge(struct ip6_msource *ims,
  128                     const struct in6_msource *lims, const int rollback);
  129 static int      in6_mc_get(struct ifnet *, const struct in6_addr *,
  130                     struct in6_multi **);
  131 static int      in6m_get_source(struct in6_multi *inm,
  132                     const struct in6_addr *addr, const int noalloc,
  133                     struct ip6_msource **pims);
  134 #ifdef KTR
  135 static int      in6m_is_ifp_detached(const struct in6_multi *);
  136 #endif
  137 static int      in6m_merge(struct in6_multi *, /*const*/ struct in6_mfilter *);
  138 static void     in6m_purge(struct in6_multi *);
  139 static void     in6m_reap(struct in6_multi *);
  140 static struct ip6_moptions *
  141                 in6p_findmoptions(struct inpcb *);
  142 static int      in6p_get_source_filters(struct inpcb *, struct sockopt *);
  143 static int      in6p_join_group(struct inpcb *, struct sockopt *);
  144 static int      in6p_leave_group(struct inpcb *, struct sockopt *);
  145 static struct ifnet *
  146                 in6p_lookup_mcast_ifp(const struct inpcb *,
  147                     const struct sockaddr_in6 *);
  148 static int      in6p_block_unblock_source(struct inpcb *, struct sockopt *);
  149 static int      in6p_set_multicast_if(struct inpcb *, struct sockopt *);
  150 static int      in6p_set_source_filters(struct inpcb *, struct sockopt *);
  151 static int      sysctl_ip6_mcast_filters(SYSCTL_HANDLER_ARGS);
  152 
  153 SYSCTL_DECL(_net_inet6_ip6);    /* XXX Not in any common header. */
  154 
  155 static SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, mcast, CTLFLAG_RW, 0,
  156     "IPv6 multicast");
  157 
  158 static u_long in6_mcast_maxgrpsrc = IPV6_MAX_GROUP_SRC_FILTER;
  159 SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxgrpsrc,
  160     CTLFLAG_RW | CTLFLAG_TUN, &in6_mcast_maxgrpsrc, 0,
  161     "Max source filters per group");
  162 TUNABLE_ULONG("net.inet6.ip6.mcast.maxgrpsrc", &in6_mcast_maxgrpsrc);
  163 
  164 static u_long in6_mcast_maxsocksrc = IPV6_MAX_SOCK_SRC_FILTER;
  165 SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxsocksrc,
  166     CTLFLAG_RW | CTLFLAG_TUN, &in6_mcast_maxsocksrc, 0,
  167     "Max source filters per socket");
  168 TUNABLE_ULONG("net.inet6.ip6.mcast.maxsocksrc", &in6_mcast_maxsocksrc);
  169 
  170 /* TODO Virtualize this switch. */
  171 int in6_mcast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
  172 SYSCTL_INT(_net_inet6_ip6_mcast, OID_AUTO, loop, CTLFLAG_RW | CTLFLAG_TUN,
  173     &in6_mcast_loop, 0, "Loopback multicast datagrams by default");
  174 TUNABLE_INT("net.inet6.ip6.mcast.loop", &in6_mcast_loop);
  175 
  176 static SYSCTL_NODE(_net_inet6_ip6_mcast, OID_AUTO, filters,
  177     CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_ip6_mcast_filters,
  178     "Per-interface stack-wide source filters");
  179 
  180 #ifdef KTR
  181 /*
  182  * Inline function which wraps assertions for a valid ifp.
  183  * The ifnet layer will set the ifma's ifp pointer to NULL if the ifp
  184  * is detached.
  185  */
  186 static int __inline
  187 in6m_is_ifp_detached(const struct in6_multi *inm)
  188 {
  189         struct ifnet *ifp;
  190 
  191         KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
  192         ifp = inm->in6m_ifma->ifma_ifp;
  193         if (ifp != NULL) {
  194                 /*
  195                  * Sanity check that network-layer notion of ifp is the
  196                  * same as that of link-layer.
  197                  */
  198                 KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
  199         }
  200 
  201         return (ifp == NULL);
  202 }
  203 #endif
  204 
  205 /*
  206  * Initialize an in6_mfilter structure to a known state at t0, t1
  207  * with an empty source filter list.
  208  */
  209 static __inline void
  210 im6f_init(struct in6_mfilter *imf, const int st0, const int st1)
  211 {
  212         memset(imf, 0, sizeof(struct in6_mfilter));
  213         RB_INIT(&imf->im6f_sources);
  214         imf->im6f_st[0] = st0;
  215         imf->im6f_st[1] = st1;
  216 }
  217 
  218 /*
  219  * Resize the ip6_moptions vector to the next power-of-two minus 1.
  220  * May be called with locks held; do not sleep.
  221  */
  222 static int
  223 im6o_grow(struct ip6_moptions *imo)
  224 {
  225         struct in6_multi        **nmships;
  226         struct in6_multi        **omships;
  227         struct in6_mfilter       *nmfilters;
  228         struct in6_mfilter       *omfilters;
  229         size_t                    idx;
  230         size_t                    newmax;
  231         size_t                    oldmax;
  232 
  233         nmships = NULL;
  234         nmfilters = NULL;
  235         omships = imo->im6o_membership;
  236         omfilters = imo->im6o_mfilters;
  237         oldmax = imo->im6o_max_memberships;
  238         newmax = ((oldmax + 1) * 2) - 1;
  239 
  240         if (newmax <= IPV6_MAX_MEMBERSHIPS) {
  241                 nmships = (struct in6_multi **)realloc(omships,
  242                     sizeof(struct in6_multi *) * newmax, M_IP6MOPTS, M_NOWAIT);
  243                 nmfilters = (struct in6_mfilter *)realloc(omfilters,
  244                     sizeof(struct in6_mfilter) * newmax, M_IN6MFILTER,
  245                     M_NOWAIT);
  246                 if (nmships != NULL && nmfilters != NULL) {
  247                         /* Initialize newly allocated source filter heads. */
  248                         for (idx = oldmax; idx < newmax; idx++) {
  249                                 im6f_init(&nmfilters[idx], MCAST_UNDEFINED,
  250                                     MCAST_EXCLUDE);
  251                         }
  252                         imo->im6o_max_memberships = newmax;
  253                         imo->im6o_membership = nmships;
  254                         imo->im6o_mfilters = nmfilters;
  255                 }
  256         }
  257 
  258         if (nmships == NULL || nmfilters == NULL) {
  259                 if (nmships != NULL)
  260                         free(nmships, M_IP6MOPTS);
  261                 if (nmfilters != NULL)
  262                         free(nmfilters, M_IN6MFILTER);
  263                 return (ETOOMANYREFS);
  264         }
  265 
  266         return (0);
  267 }
  268 
  269 /*
  270  * Find an IPv6 multicast group entry for this ip6_moptions instance
  271  * which matches the specified group, and optionally an interface.
  272  * Return its index into the array, or -1 if not found.
  273  */
  274 static size_t
  275 im6o_match_group(const struct ip6_moptions *imo, const struct ifnet *ifp,
  276     const struct sockaddr *group)
  277 {
  278         const struct sockaddr_in6 *gsin6;
  279         struct in6_multi        **pinm;
  280         int               idx;
  281         int               nmships;
  282 
  283         gsin6 = (const struct sockaddr_in6 *)group;
  284 
  285         /* The im6o_membership array may be lazy allocated. */
  286         if (imo->im6o_membership == NULL || imo->im6o_num_memberships == 0)
  287                 return (-1);
  288 
  289         nmships = imo->im6o_num_memberships;
  290         pinm = &imo->im6o_membership[0];
  291         for (idx = 0; idx < nmships; idx++, pinm++) {
  292                 if (*pinm == NULL)
  293                         continue;
  294                 if ((ifp == NULL || ((*pinm)->in6m_ifp == ifp)) &&
  295                     IN6_ARE_ADDR_EQUAL(&(*pinm)->in6m_addr,
  296                     &gsin6->sin6_addr)) {
  297                         break;
  298                 }
  299         }
  300         if (idx >= nmships)
  301                 idx = -1;
  302 
  303         return (idx);
  304 }
  305 
  306 /*
  307  * Find an IPv6 multicast source entry for this imo which matches
  308  * the given group index for this socket, and source address.
  309  *
  310  * XXX TODO: The scope ID, if present in src, is stripped before
  311  * any comparison. We SHOULD enforce scope/zone checks where the source
  312  * filter entry has a link scope.
  313  *
  314  * NOTE: This does not check if the entry is in-mode, merely if
  315  * it exists, which may not be the desired behaviour.
  316  */
  317 static struct in6_msource *
  318 im6o_match_source(const struct ip6_moptions *imo, const size_t gidx,
  319     const struct sockaddr *src)
  320 {
  321         struct ip6_msource       find;
  322         struct in6_mfilter      *imf;
  323         struct ip6_msource      *ims;
  324         const sockunion_t       *psa;
  325 
  326         KASSERT(src->sa_family == AF_INET6, ("%s: !AF_INET6", __func__));
  327         KASSERT(gidx != -1 && gidx < imo->im6o_num_memberships,
  328             ("%s: invalid index %d\n", __func__, (int)gidx));
  329 
  330         /* The im6o_mfilters array may be lazy allocated. */
  331         if (imo->im6o_mfilters == NULL)
  332                 return (NULL);
  333         imf = &imo->im6o_mfilters[gidx];
  334 
  335         psa = (const sockunion_t *)src;
  336         find.im6s_addr = psa->sin6.sin6_addr;
  337         in6_clearscope(&find.im6s_addr);                /* XXX */
  338         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  339 
  340         return ((struct in6_msource *)ims);
  341 }
  342 
  343 /*
  344  * Perform filtering for multicast datagrams on a socket by group and source.
  345  *
  346  * Returns 0 if a datagram should be allowed through, or various error codes
  347  * if the socket was not a member of the group, or the source was muted, etc.
  348  */
  349 int
  350 im6o_mc_filter(const struct ip6_moptions *imo, const struct ifnet *ifp,
  351     const struct sockaddr *group, const struct sockaddr *src)
  352 {
  353         size_t gidx;
  354         struct in6_msource *ims;
  355         int mode;
  356 
  357         KASSERT(ifp != NULL, ("%s: null ifp", __func__));
  358 
  359         gidx = im6o_match_group(imo, ifp, group);
  360         if (gidx == -1)
  361                 return (MCAST_NOTGMEMBER);
  362 
  363         /*
  364          * Check if the source was included in an (S,G) join.
  365          * Allow reception on exclusive memberships by default,
  366          * reject reception on inclusive memberships by default.
  367          * Exclude source only if an in-mode exclude filter exists.
  368          * Include source only if an in-mode include filter exists.
  369          * NOTE: We are comparing group state here at MLD t1 (now)
  370          * with socket-layer t0 (since last downcall).
  371          */
  372         mode = imo->im6o_mfilters[gidx].im6f_st[1];
  373         ims = im6o_match_source(imo, gidx, src);
  374 
  375         if ((ims == NULL && mode == MCAST_INCLUDE) ||
  376             (ims != NULL && ims->im6sl_st[0] != mode))
  377                 return (MCAST_NOTSMEMBER);
  378 
  379         return (MCAST_PASS);
  380 }
  381 
  382 /*
  383  * Find and return a reference to an in6_multi record for (ifp, group),
  384  * and bump its reference count.
  385  * If one does not exist, try to allocate it, and update link-layer multicast
  386  * filters on ifp to listen for group.
  387  * Assumes the IN6_MULTI lock is held across the call.
  388  * Return 0 if successful, otherwise return an appropriate error code.
  389  */
  390 static int
  391 in6_mc_get(struct ifnet *ifp, const struct in6_addr *group,
  392     struct in6_multi **pinm)
  393 {
  394         struct sockaddr_in6      gsin6;
  395         struct ifmultiaddr      *ifma;
  396         struct in6_multi        *inm;
  397         int                      error;
  398 
  399         error = 0;
  400 
  401         /*
  402          * XXX: Accesses to ifma_protospec must be covered by IF_ADDR_LOCK;
  403          * if_addmulti() takes this mutex itself, so we must drop and
  404          * re-acquire around the call.
  405          */
  406         IN6_MULTI_LOCK_ASSERT();
  407         IF_ADDR_WLOCK(ifp);
  408 
  409         inm = in6m_lookup_locked(ifp, group);
  410         if (inm != NULL) {
  411                 /*
  412                  * If we already joined this group, just bump the
  413                  * refcount and return it.
  414                  */
  415                 KASSERT(inm->in6m_refcount >= 1,
  416                     ("%s: bad refcount %d", __func__, inm->in6m_refcount));
  417                 ++inm->in6m_refcount;
  418                 *pinm = inm;
  419                 goto out_locked;
  420         }
  421 
  422         memset(&gsin6, 0, sizeof(gsin6));
  423         gsin6.sin6_family = AF_INET6;
  424         gsin6.sin6_len = sizeof(struct sockaddr_in6);
  425         gsin6.sin6_addr = *group;
  426 
  427         /*
  428          * Check if a link-layer group is already associated
  429          * with this network-layer group on the given ifnet.
  430          */
  431         IF_ADDR_WUNLOCK(ifp);
  432         error = if_addmulti(ifp, (struct sockaddr *)&gsin6, &ifma);
  433         if (error != 0)
  434                 return (error);
  435         IF_ADDR_WLOCK(ifp);
  436 
  437         /*
  438          * If something other than netinet6 is occupying the link-layer
  439          * group, print a meaningful error message and back out of
  440          * the allocation.
  441          * Otherwise, bump the refcount on the existing network-layer
  442          * group association and return it.
  443          */
  444         if (ifma->ifma_protospec != NULL) {
  445                 inm = (struct in6_multi *)ifma->ifma_protospec;
  446 #ifdef INVARIANTS
  447                 KASSERT(ifma->ifma_addr != NULL, ("%s: no ifma_addr",
  448                     __func__));
  449                 KASSERT(ifma->ifma_addr->sa_family == AF_INET6,
  450                     ("%s: ifma not AF_INET6", __func__));
  451                 KASSERT(inm != NULL, ("%s: no ifma_protospec", __func__));
  452                 if (inm->in6m_ifma != ifma || inm->in6m_ifp != ifp ||
  453                     !IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, group))
  454                         panic("%s: ifma %p is inconsistent with %p (%p)",
  455                             __func__, ifma, inm, group);
  456 #endif
  457                 ++inm->in6m_refcount;
  458                 *pinm = inm;
  459                 goto out_locked;
  460         }
  461 
  462         IF_ADDR_WLOCK_ASSERT(ifp);
  463 
  464         /*
  465          * A new in6_multi record is needed; allocate and initialize it.
  466          * We DO NOT perform an MLD join as the in6_ layer may need to
  467          * push an initial source list down to MLD to support SSM.
  468          *
  469          * The initial source filter state is INCLUDE, {} as per the RFC.
  470          * Pending state-changes per group are subject to a bounds check.
  471          */
  472         inm = malloc(sizeof(*inm), M_IP6MADDR, M_NOWAIT | M_ZERO);
  473         if (inm == NULL) {
  474                 if_delmulti_ifma(ifma);
  475                 error = ENOMEM;
  476                 goto out_locked;
  477         }
  478         inm->in6m_addr = *group;
  479         inm->in6m_ifp = ifp;
  480         inm->in6m_mli = MLD_IFINFO(ifp);
  481         inm->in6m_ifma = ifma;
  482         inm->in6m_refcount = 1;
  483         inm->in6m_state = MLD_NOT_MEMBER;
  484         IFQ_SET_MAXLEN(&inm->in6m_scq, MLD_MAX_STATE_CHANGES);
  485 
  486         inm->in6m_st[0].iss_fmode = MCAST_UNDEFINED;
  487         inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
  488         RB_INIT(&inm->in6m_srcs);
  489 
  490         ifma->ifma_protospec = inm;
  491         *pinm = inm;
  492 
  493 out_locked:
  494         IF_ADDR_WUNLOCK(ifp);
  495         return (error);
  496 }
  497 
  498 /*
  499  * Drop a reference to an in6_multi record.
  500  *
  501  * If the refcount drops to 0, free the in6_multi record and
  502  * delete the underlying link-layer membership.
  503  */
  504 void
  505 in6m_release_locked(struct in6_multi *inm)
  506 {
  507         struct ifmultiaddr *ifma;
  508 
  509         IN6_MULTI_LOCK_ASSERT();
  510 
  511         CTR2(KTR_MLD, "%s: refcount is %d", __func__, inm->in6m_refcount);
  512 
  513         if (--inm->in6m_refcount > 0) {
  514                 CTR2(KTR_MLD, "%s: refcount is now %d", __func__,
  515                     inm->in6m_refcount);
  516                 return;
  517         }
  518 
  519         CTR2(KTR_MLD, "%s: freeing inm %p", __func__, inm);
  520 
  521         ifma = inm->in6m_ifma;
  522 
  523         /* XXX this access is not covered by IF_ADDR_LOCK */
  524         CTR2(KTR_MLD, "%s: purging ifma %p", __func__, ifma);
  525         KASSERT(ifma->ifma_protospec == inm,
  526             ("%s: ifma_protospec != inm", __func__));
  527         ifma->ifma_protospec = NULL;
  528 
  529         in6m_purge(inm);
  530 
  531         free(inm, M_IP6MADDR);
  532 
  533         if_delmulti_ifma(ifma);
  534 }
  535 
  536 /*
  537  * Clear recorded source entries for a group.
  538  * Used by the MLD code. Caller must hold the IN6_MULTI lock.
  539  * FIXME: Should reap.
  540  */
  541 void
  542 in6m_clear_recorded(struct in6_multi *inm)
  543 {
  544         struct ip6_msource      *ims;
  545 
  546         IN6_MULTI_LOCK_ASSERT();
  547 
  548         RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
  549                 if (ims->im6s_stp) {
  550                         ims->im6s_stp = 0;
  551                         --inm->in6m_st[1].iss_rec;
  552                 }
  553         }
  554         KASSERT(inm->in6m_st[1].iss_rec == 0,
  555             ("%s: iss_rec %d not 0", __func__, inm->in6m_st[1].iss_rec));
  556 }
  557 
  558 /*
  559  * Record a source as pending for a Source-Group MLDv2 query.
  560  * This lives here as it modifies the shared tree.
  561  *
  562  * inm is the group descriptor.
  563  * naddr is the address of the source to record in network-byte order.
  564  *
  565  * If the net.inet6.mld.sgalloc sysctl is non-zero, we will
  566  * lazy-allocate a source node in response to an SG query.
  567  * Otherwise, no allocation is performed. This saves some memory
  568  * with the trade-off that the source will not be reported to the
  569  * router if joined in the window between the query response and
  570  * the group actually being joined on the local host.
  571  *
  572  * VIMAGE: XXX: Currently the mld_sgalloc feature has been removed.
  573  * This turns off the allocation of a recorded source entry if
  574  * the group has not been joined.
  575  *
  576  * Return 0 if the source didn't exist or was already marked as recorded.
  577  * Return 1 if the source was marked as recorded by this function.
  578  * Return <0 if any error occured (negated errno code).
  579  */
  580 int
  581 in6m_record_source(struct in6_multi *inm, const struct in6_addr *addr)
  582 {
  583         struct ip6_msource       find;
  584         struct ip6_msource      *ims, *nims;
  585 
  586         IN6_MULTI_LOCK_ASSERT();
  587 
  588         find.im6s_addr = *addr;
  589         ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
  590         if (ims && ims->im6s_stp)
  591                 return (0);
  592         if (ims == NULL) {
  593                 if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
  594                         return (-ENOSPC);
  595                 nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
  596                     M_NOWAIT | M_ZERO);
  597                 if (nims == NULL)
  598                         return (-ENOMEM);
  599                 nims->im6s_addr = find.im6s_addr;
  600                 RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
  601                 ++inm->in6m_nsrc;
  602                 ims = nims;
  603         }
  604 
  605         /*
  606          * Mark the source as recorded and update the recorded
  607          * source count.
  608          */
  609         ++ims->im6s_stp;
  610         ++inm->in6m_st[1].iss_rec;
  611 
  612         return (1);
  613 }
  614 
  615 /*
  616  * Return a pointer to an in6_msource owned by an in6_mfilter,
  617  * given its source address.
  618  * Lazy-allocate if needed. If this is a new entry its filter state is
  619  * undefined at t0.
  620  *
  621  * imf is the filter set being modified.
  622  * addr is the source address.
  623  *
  624  * SMPng: May be called with locks held; malloc must not block.
  625  */
  626 static int
  627 im6f_get_source(struct in6_mfilter *imf, const struct sockaddr_in6 *psin,
  628     struct in6_msource **plims)
  629 {
  630         struct ip6_msource       find;
  631         struct ip6_msource      *ims, *nims;
  632         struct in6_msource      *lims;
  633         int                      error;
  634 
  635         error = 0;
  636         ims = NULL;
  637         lims = NULL;
  638 
  639         find.im6s_addr = psin->sin6_addr;
  640         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  641         lims = (struct in6_msource *)ims;
  642         if (lims == NULL) {
  643                 if (imf->im6f_nsrc == in6_mcast_maxsocksrc)
  644                         return (ENOSPC);
  645                 nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
  646                     M_NOWAIT | M_ZERO);
  647                 if (nims == NULL)
  648                         return (ENOMEM);
  649                 lims = (struct in6_msource *)nims;
  650                 lims->im6s_addr = find.im6s_addr;
  651                 lims->im6sl_st[0] = MCAST_UNDEFINED;
  652                 RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
  653                 ++imf->im6f_nsrc;
  654         }
  655 
  656         *plims = lims;
  657 
  658         return (error);
  659 }
  660 
  661 /*
  662  * Graft a source entry into an existing socket-layer filter set,
  663  * maintaining any required invariants and checking allocations.
  664  *
  665  * The source is marked as being in the new filter mode at t1.
  666  *
  667  * Return the pointer to the new node, otherwise return NULL.
  668  */
  669 static struct in6_msource *
  670 im6f_graft(struct in6_mfilter *imf, const uint8_t st1,
  671     const struct sockaddr_in6 *psin)
  672 {
  673         struct ip6_msource      *nims;
  674         struct in6_msource      *lims;
  675 
  676         nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
  677             M_NOWAIT | M_ZERO);
  678         if (nims == NULL)
  679                 return (NULL);
  680         lims = (struct in6_msource *)nims;
  681         lims->im6s_addr = psin->sin6_addr;
  682         lims->im6sl_st[0] = MCAST_UNDEFINED;
  683         lims->im6sl_st[1] = st1;
  684         RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
  685         ++imf->im6f_nsrc;
  686 
  687         return (lims);
  688 }
  689 
  690 /*
  691  * Prune a source entry from an existing socket-layer filter set,
  692  * maintaining any required invariants and checking allocations.
  693  *
  694  * The source is marked as being left at t1, it is not freed.
  695  *
  696  * Return 0 if no error occurred, otherwise return an errno value.
  697  */
  698 static int
  699 im6f_prune(struct in6_mfilter *imf, const struct sockaddr_in6 *psin)
  700 {
  701         struct ip6_msource       find;
  702         struct ip6_msource      *ims;
  703         struct in6_msource      *lims;
  704 
  705         find.im6s_addr = psin->sin6_addr;
  706         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  707         if (ims == NULL)
  708                 return (ENOENT);
  709         lims = (struct in6_msource *)ims;
  710         lims->im6sl_st[1] = MCAST_UNDEFINED;
  711         return (0);
  712 }
  713 
  714 /*
  715  * Revert socket-layer filter set deltas at t1 to t0 state.
  716  */
  717 static void
  718 im6f_rollback(struct in6_mfilter *imf)
  719 {
  720         struct ip6_msource      *ims, *tims;
  721         struct in6_msource      *lims;
  722 
  723         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  724                 lims = (struct in6_msource *)ims;
  725                 if (lims->im6sl_st[0] == lims->im6sl_st[1]) {
  726                         /* no change at t1 */
  727                         continue;
  728                 } else if (lims->im6sl_st[0] != MCAST_UNDEFINED) {
  729                         /* revert change to existing source at t1 */
  730                         lims->im6sl_st[1] = lims->im6sl_st[0];
  731                 } else {
  732                         /* revert source added t1 */
  733                         CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
  734                         RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  735                         free(ims, M_IN6MFILTER);
  736                         imf->im6f_nsrc--;
  737                 }
  738         }
  739         imf->im6f_st[1] = imf->im6f_st[0];
  740 }
  741 
  742 /*
  743  * Mark socket-layer filter set as INCLUDE {} at t1.
  744  */
  745 static void
  746 im6f_leave(struct in6_mfilter *imf)
  747 {
  748         struct ip6_msource      *ims;
  749         struct in6_msource      *lims;
  750 
  751         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  752                 lims = (struct in6_msource *)ims;
  753                 lims->im6sl_st[1] = MCAST_UNDEFINED;
  754         }
  755         imf->im6f_st[1] = MCAST_INCLUDE;
  756 }
  757 
  758 /*
  759  * Mark socket-layer filter set deltas as committed.
  760  */
  761 static void
  762 im6f_commit(struct in6_mfilter *imf)
  763 {
  764         struct ip6_msource      *ims;
  765         struct in6_msource      *lims;
  766 
  767         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  768                 lims = (struct in6_msource *)ims;
  769                 lims->im6sl_st[0] = lims->im6sl_st[1];
  770         }
  771         imf->im6f_st[0] = imf->im6f_st[1];
  772 }
  773 
  774 /*
  775  * Reap unreferenced sources from socket-layer filter set.
  776  */
  777 static void
  778 im6f_reap(struct in6_mfilter *imf)
  779 {
  780         struct ip6_msource      *ims, *tims;
  781         struct in6_msource      *lims;
  782 
  783         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  784                 lims = (struct in6_msource *)ims;
  785                 if ((lims->im6sl_st[0] == MCAST_UNDEFINED) &&
  786                     (lims->im6sl_st[1] == MCAST_UNDEFINED)) {
  787                         CTR2(KTR_MLD, "%s: free lims %p", __func__, ims);
  788                         RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  789                         free(ims, M_IN6MFILTER);
  790                         imf->im6f_nsrc--;
  791                 }
  792         }
  793 }
  794 
  795 /*
  796  * Purge socket-layer filter set.
  797  */
  798 static void
  799 im6f_purge(struct in6_mfilter *imf)
  800 {
  801         struct ip6_msource      *ims, *tims;
  802 
  803         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  804                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
  805                 RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  806                 free(ims, M_IN6MFILTER);
  807                 imf->im6f_nsrc--;
  808         }
  809         imf->im6f_st[0] = imf->im6f_st[1] = MCAST_UNDEFINED;
  810         KASSERT(RB_EMPTY(&imf->im6f_sources),
  811             ("%s: im6f_sources not empty", __func__));
  812 }
  813 
  814 /*
  815  * Look up a source filter entry for a multicast group.
  816  *
  817  * inm is the group descriptor to work with.
  818  * addr is the IPv6 address to look up.
  819  * noalloc may be non-zero to suppress allocation of sources.
  820  * *pims will be set to the address of the retrieved or allocated source.
  821  *
  822  * SMPng: NOTE: may be called with locks held.
  823  * Return 0 if successful, otherwise return a non-zero error code.
  824  */
  825 static int
  826 in6m_get_source(struct in6_multi *inm, const struct in6_addr *addr,
  827     const int noalloc, struct ip6_msource **pims)
  828 {
  829         struct ip6_msource       find;
  830         struct ip6_msource      *ims, *nims;
  831 #ifdef KTR
  832         char                     ip6tbuf[INET6_ADDRSTRLEN];
  833 #endif
  834 
  835         find.im6s_addr = *addr;
  836         ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
  837         if (ims == NULL && !noalloc) {
  838                 if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
  839                         return (ENOSPC);
  840                 nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
  841                     M_NOWAIT | M_ZERO);
  842                 if (nims == NULL)
  843                         return (ENOMEM);
  844                 nims->im6s_addr = *addr;
  845                 RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
  846                 ++inm->in6m_nsrc;
  847                 ims = nims;
  848                 CTR3(KTR_MLD, "%s: allocated %s as %p", __func__,
  849                     ip6_sprintf(ip6tbuf, addr), ims);
  850         }
  851 
  852         *pims = ims;
  853         return (0);
  854 }
  855 
  856 /*
  857  * Merge socket-layer source into MLD-layer source.
  858  * If rollback is non-zero, perform the inverse of the merge.
  859  */
  860 static void
  861 im6s_merge(struct ip6_msource *ims, const struct in6_msource *lims,
  862     const int rollback)
  863 {
  864         int n = rollback ? -1 : 1;
  865 #ifdef KTR
  866         char ip6tbuf[INET6_ADDRSTRLEN];
  867 
  868         ip6_sprintf(ip6tbuf, &lims->im6s_addr);
  869 #endif
  870 
  871         if (lims->im6sl_st[0] == MCAST_EXCLUDE) {
  872                 CTR3(KTR_MLD, "%s: t1 ex -= %d on %s", __func__, n, ip6tbuf);
  873                 ims->im6s_st[1].ex -= n;
  874         } else if (lims->im6sl_st[0] == MCAST_INCLUDE) {
  875                 CTR3(KTR_MLD, "%s: t1 in -= %d on %s", __func__, n, ip6tbuf);
  876                 ims->im6s_st[1].in -= n;
  877         }
  878 
  879         if (lims->im6sl_st[1] == MCAST_EXCLUDE) {
  880                 CTR3(KTR_MLD, "%s: t1 ex += %d on %s", __func__, n, ip6tbuf);
  881                 ims->im6s_st[1].ex += n;
  882         } else if (lims->im6sl_st[1] == MCAST_INCLUDE) {
  883                 CTR3(KTR_MLD, "%s: t1 in += %d on %s", __func__, n, ip6tbuf);
  884                 ims->im6s_st[1].in += n;
  885         }
  886 }
  887 
  888 /*
  889  * Atomically update the global in6_multi state, when a membership's
  890  * filter list is being updated in any way.
  891  *
  892  * imf is the per-inpcb-membership group filter pointer.
  893  * A fake imf may be passed for in-kernel consumers.
  894  *
  895  * XXX This is a candidate for a set-symmetric-difference style loop
  896  * which would eliminate the repeated lookup from root of ims nodes,
  897  * as they share the same key space.
  898  *
  899  * If any error occurred this function will back out of refcounts
  900  * and return a non-zero value.
  901  */
  902 static int
  903 in6m_merge(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
  904 {
  905         struct ip6_msource      *ims, *nims;
  906         struct in6_msource      *lims;
  907         int                      schanged, error;
  908         int                      nsrc0, nsrc1;
  909 
  910         schanged = 0;
  911         error = 0;
  912         nsrc1 = nsrc0 = 0;
  913 
  914         /*
  915          * Update the source filters first, as this may fail.
  916          * Maintain count of in-mode filters at t0, t1. These are
  917          * used to work out if we transition into ASM mode or not.
  918          * Maintain a count of source filters whose state was
  919          * actually modified by this operation.
  920          */
  921         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  922                 lims = (struct in6_msource *)ims;
  923                 if (lims->im6sl_st[0] == imf->im6f_st[0]) nsrc0++;
  924                 if (lims->im6sl_st[1] == imf->im6f_st[1]) nsrc1++;
  925                 if (lims->im6sl_st[0] == lims->im6sl_st[1]) continue;
  926                 error = in6m_get_source(inm, &lims->im6s_addr, 0, &nims);
  927                 ++schanged;
  928                 if (error)
  929                         break;
  930                 im6s_merge(nims, lims, 0);
  931         }
  932         if (error) {
  933                 struct ip6_msource *bims;
  934 
  935                 RB_FOREACH_REVERSE_FROM(ims, ip6_msource_tree, nims) {
  936                         lims = (struct in6_msource *)ims;
  937                         if (lims->im6sl_st[0] == lims->im6sl_st[1])
  938                                 continue;
  939                         (void)in6m_get_source(inm, &lims->im6s_addr, 1, &bims);
  940                         if (bims == NULL)
  941                                 continue;
  942                         im6s_merge(bims, lims, 1);
  943                 }
  944                 goto out_reap;
  945         }
  946 
  947         CTR3(KTR_MLD, "%s: imf filters in-mode: %d at t0, %d at t1",
  948             __func__, nsrc0, nsrc1);
  949 
  950         /* Handle transition between INCLUDE {n} and INCLUDE {} on socket. */
  951         if (imf->im6f_st[0] == imf->im6f_st[1] &&
  952             imf->im6f_st[1] == MCAST_INCLUDE) {
  953                 if (nsrc1 == 0) {
  954                         CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
  955                         --inm->in6m_st[1].iss_in;
  956                 }
  957         }
  958 
  959         /* Handle filter mode transition on socket. */
  960         if (imf->im6f_st[0] != imf->im6f_st[1]) {
  961                 CTR3(KTR_MLD, "%s: imf transition %d to %d",
  962                     __func__, imf->im6f_st[0], imf->im6f_st[1]);
  963 
  964                 if (imf->im6f_st[0] == MCAST_EXCLUDE) {
  965                         CTR1(KTR_MLD, "%s: --ex on inm at t1", __func__);
  966                         --inm->in6m_st[1].iss_ex;
  967                 } else if (imf->im6f_st[0] == MCAST_INCLUDE) {
  968                         CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
  969                         --inm->in6m_st[1].iss_in;
  970                 }
  971 
  972                 if (imf->im6f_st[1] == MCAST_EXCLUDE) {
  973                         CTR1(KTR_MLD, "%s: ex++ on inm at t1", __func__);
  974                         inm->in6m_st[1].iss_ex++;
  975                 } else if (imf->im6f_st[1] == MCAST_INCLUDE && nsrc1 > 0) {
  976                         CTR1(KTR_MLD, "%s: in++ on inm at t1", __func__);
  977                         inm->in6m_st[1].iss_in++;
  978                 }
  979         }
  980 
  981         /*
  982          * Track inm filter state in terms of listener counts.
  983          * If there are any exclusive listeners, stack-wide
  984          * membership is exclusive.
  985          * Otherwise, if only inclusive listeners, stack-wide is inclusive.
  986          * If no listeners remain, state is undefined at t1,
  987          * and the MLD lifecycle for this group should finish.
  988          */
  989         if (inm->in6m_st[1].iss_ex > 0) {
  990                 CTR1(KTR_MLD, "%s: transition to EX", __func__);
  991                 inm->in6m_st[1].iss_fmode = MCAST_EXCLUDE;
  992         } else if (inm->in6m_st[1].iss_in > 0) {
  993                 CTR1(KTR_MLD, "%s: transition to IN", __func__);
  994                 inm->in6m_st[1].iss_fmode = MCAST_INCLUDE;
  995         } else {
  996                 CTR1(KTR_MLD, "%s: transition to UNDEF", __func__);
  997                 inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
  998         }
  999 
 1000         /* Decrement ASM listener count on transition out of ASM mode. */
 1001         if (imf->im6f_st[0] == MCAST_EXCLUDE && nsrc0 == 0) {
 1002                 if ((imf->im6f_st[1] != MCAST_EXCLUDE) ||
 1003                     (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 > 0))
 1004                         CTR1(KTR_MLD, "%s: --asm on inm at t1", __func__);
 1005                         --inm->in6m_st[1].iss_asm;
 1006         }
 1007 
 1008         /* Increment ASM listener count on transition to ASM mode. */
 1009         if (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 == 0) {
 1010                 CTR1(KTR_MLD, "%s: asm++ on inm at t1", __func__);
 1011                 inm->in6m_st[1].iss_asm++;
 1012         }
 1013 
 1014         CTR3(KTR_MLD, "%s: merged imf %p to inm %p", __func__, imf, inm);
 1015         in6m_print(inm);
 1016 
 1017 out_reap:
 1018         if (schanged > 0) {
 1019                 CTR1(KTR_MLD, "%s: sources changed; reaping", __func__);
 1020                 in6m_reap(inm);
 1021         }
 1022         return (error);
 1023 }
 1024 
 1025 /*
 1026  * Mark an in6_multi's filter set deltas as committed.
 1027  * Called by MLD after a state change has been enqueued.
 1028  */
 1029 void
 1030 in6m_commit(struct in6_multi *inm)
 1031 {
 1032         struct ip6_msource      *ims;
 1033 
 1034         CTR2(KTR_MLD, "%s: commit inm %p", __func__, inm);
 1035         CTR1(KTR_MLD, "%s: pre commit:", __func__);
 1036         in6m_print(inm);
 1037 
 1038         RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
 1039                 ims->im6s_st[0] = ims->im6s_st[1];
 1040         }
 1041         inm->in6m_st[0] = inm->in6m_st[1];
 1042 }
 1043 
 1044 /*
 1045  * Reap unreferenced nodes from an in6_multi's filter set.
 1046  */
 1047 static void
 1048 in6m_reap(struct in6_multi *inm)
 1049 {
 1050         struct ip6_msource      *ims, *tims;
 1051 
 1052         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1053                 if (ims->im6s_st[0].ex > 0 || ims->im6s_st[0].in > 0 ||
 1054                     ims->im6s_st[1].ex > 0 || ims->im6s_st[1].in > 0 ||
 1055                     ims->im6s_stp != 0)
 1056                         continue;
 1057                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1058                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1059                 free(ims, M_IP6MSOURCE);
 1060                 inm->in6m_nsrc--;
 1061         }
 1062 }
 1063 
 1064 /*
 1065  * Purge all source nodes from an in6_multi's filter set.
 1066  */
 1067 static void
 1068 in6m_purge(struct in6_multi *inm)
 1069 {
 1070         struct ip6_msource      *ims, *tims;
 1071 
 1072         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1073                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1074                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1075                 free(ims, M_IP6MSOURCE);
 1076                 inm->in6m_nsrc--;
 1077         }
 1078         /* Free state-change requests that might be queued. */
 1079         _IF_DRAIN(&inm->in6m_scq);
 1080 }
 1081 
 1082 /*
 1083  * Join a multicast address w/o sources.
 1084  * KAME compatibility entry point.
 1085  *
 1086  * SMPng: Assume no mc locks held by caller.
 1087  */
 1088 struct in6_multi_mship *
 1089 in6_joingroup(struct ifnet *ifp, struct in6_addr *mcaddr,
 1090     int *errorp, int delay)
 1091 {
 1092         struct in6_multi_mship *imm;
 1093         int error;
 1094 
 1095         imm = malloc(sizeof(*imm), M_IP6MADDR, M_NOWAIT);
 1096         if (imm == NULL) {
 1097                 *errorp = ENOBUFS;
 1098                 return (NULL);
 1099         }
 1100 
 1101         delay = (delay * PR_FASTHZ) / hz;
 1102 
 1103         error = in6_mc_join(ifp, mcaddr, NULL, &imm->i6mm_maddr, delay);
 1104         if (error) {
 1105                 *errorp = error;
 1106                 free(imm, M_IP6MADDR);
 1107                 return (NULL);
 1108         }
 1109 
 1110         return (imm);
 1111 }
 1112 
 1113 /*
 1114  * Leave a multicast address w/o sources.
 1115  * KAME compatibility entry point.
 1116  *
 1117  * SMPng: Assume no mc locks held by caller.
 1118  */
 1119 int
 1120 in6_leavegroup(struct in6_multi_mship *imm)
 1121 {
 1122 
 1123         if (imm->i6mm_maddr != NULL)
 1124                 in6_mc_leave(imm->i6mm_maddr, NULL);
 1125         free(imm,  M_IP6MADDR);
 1126         return 0;
 1127 }
 1128 
 1129 /*
 1130  * Join a multicast group; unlocked entry point.
 1131  *
 1132  * SMPng: XXX: in6_mc_join() is called from in6_control() when upper
 1133  * locks are not held. Fortunately, ifp is unlikely to have been detached
 1134  * at this point, so we assume it's OK to recurse.
 1135  */
 1136 int
 1137 in6_mc_join(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1138     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1139     const int delay)
 1140 {
 1141         int error;
 1142 
 1143         IN6_MULTI_LOCK();
 1144         error = in6_mc_join_locked(ifp, mcaddr, imf, pinm, delay);
 1145         IN6_MULTI_UNLOCK();
 1146 
 1147         return (error);
 1148 }
 1149 
 1150 /*
 1151  * Join a multicast group; real entry point.
 1152  *
 1153  * Only preserves atomicity at inm level.
 1154  * NOTE: imf argument cannot be const due to sys/tree.h limitations.
 1155  *
 1156  * If the MLD downcall fails, the group is not joined, and an error
 1157  * code is returned.
 1158  */
 1159 int
 1160 in6_mc_join_locked(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1161     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1162     const int delay)
 1163 {
 1164         struct in6_mfilter       timf;
 1165         struct in6_multi        *inm;
 1166         int                      error;
 1167 #ifdef KTR
 1168         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1169 #endif
 1170 
 1171 #ifdef INVARIANTS
 1172         /*
 1173          * Sanity: Check scope zone ID was set for ifp, if and
 1174          * only if group is scoped to an interface.
 1175          */
 1176         KASSERT(IN6_IS_ADDR_MULTICAST(mcaddr),
 1177             ("%s: not a multicast address", __func__));
 1178         if (IN6_IS_ADDR_MC_LINKLOCAL(mcaddr) ||
 1179             IN6_IS_ADDR_MC_INTFACELOCAL(mcaddr)) {
 1180                 KASSERT(mcaddr->s6_addr16[1] != 0,
 1181                     ("%s: scope zone ID not set", __func__));
 1182         }
 1183 #endif
 1184 
 1185         IN6_MULTI_LOCK_ASSERT();
 1186 
 1187         CTR4(KTR_MLD, "%s: join %s on %p(%s))", __func__,
 1188             ip6_sprintf(ip6tbuf, mcaddr), ifp, ifp->if_xname);
 1189 
 1190         error = 0;
 1191         inm = NULL;
 1192 
 1193         /*
 1194          * If no imf was specified (i.e. kernel consumer),
 1195          * fake one up and assume it is an ASM join.
 1196          */
 1197         if (imf == NULL) {
 1198                 im6f_init(&timf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 1199                 imf = &timf;
 1200         }
 1201 
 1202         error = in6_mc_get(ifp, mcaddr, &inm);
 1203         if (error) {
 1204                 CTR1(KTR_MLD, "%s: in6_mc_get() failure", __func__);
 1205                 return (error);
 1206         }
 1207 
 1208         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1209         error = in6m_merge(inm, imf);
 1210         if (error) {
 1211                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1212                 goto out_in6m_release;
 1213         }
 1214 
 1215         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1216         error = mld_change_state(inm, delay);
 1217         if (error) {
 1218                 CTR1(KTR_MLD, "%s: failed to update source", __func__);
 1219                 goto out_in6m_release;
 1220         }
 1221 
 1222 out_in6m_release:
 1223         if (error) {
 1224                 CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1225                 in6m_release_locked(inm);
 1226         } else {
 1227                 *pinm = inm;
 1228         }
 1229 
 1230         return (error);
 1231 }
 1232 
 1233 /*
 1234  * Leave a multicast group; unlocked entry point.
 1235  */
 1236 int
 1237 in6_mc_leave(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1238 {
 1239         struct ifnet *ifp;
 1240         int error;
 1241 
 1242         ifp = inm->in6m_ifp;
 1243 
 1244         IN6_MULTI_LOCK();
 1245         error = in6_mc_leave_locked(inm, imf);
 1246         IN6_MULTI_UNLOCK();
 1247 
 1248         return (error);
 1249 }
 1250 
 1251 /*
 1252  * Leave a multicast group; real entry point.
 1253  * All source filters will be expunged.
 1254  *
 1255  * Only preserves atomicity at inm level.
 1256  *
 1257  * Holding the write lock for the INP which contains imf
 1258  * is highly advisable. We can't assert for it as imf does not
 1259  * contain a back-pointer to the owning inp.
 1260  *
 1261  * Note: This is not the same as in6m_release(*) as this function also
 1262  * makes a state change downcall into MLD.
 1263  */
 1264 int
 1265 in6_mc_leave_locked(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1266 {
 1267         struct in6_mfilter       timf;
 1268         int                      error;
 1269 #ifdef KTR
 1270         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1271 #endif
 1272 
 1273         error = 0;
 1274 
 1275         IN6_MULTI_LOCK_ASSERT();
 1276 
 1277         CTR5(KTR_MLD, "%s: leave inm %p, %s/%s, imf %p", __func__,
 1278             inm, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 1279             (in6m_is_ifp_detached(inm) ? "null" : inm->in6m_ifp->if_xname),
 1280             imf);
 1281 
 1282         /*
 1283          * If no imf was specified (i.e. kernel consumer),
 1284          * fake one up and assume it is an ASM join.
 1285          */
 1286         if (imf == NULL) {
 1287                 im6f_init(&timf, MCAST_EXCLUDE, MCAST_UNDEFINED);
 1288                 imf = &timf;
 1289         }
 1290 
 1291         /*
 1292          * Begin state merge transaction at MLD layer.
 1293          *
 1294          * As this particular invocation should not cause any memory
 1295          * to be allocated, and there is no opportunity to roll back
 1296          * the transaction, it MUST NOT fail.
 1297          */
 1298         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1299         error = in6m_merge(inm, imf);
 1300         KASSERT(error == 0, ("%s: failed to merge inm state", __func__));
 1301 
 1302         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1303         error = mld_change_state(inm, 0);
 1304         if (error)
 1305                 CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1306 
 1307         CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1308         in6m_release_locked(inm);
 1309 
 1310         return (error);
 1311 }
 1312 
 1313 /*
 1314  * Block or unblock an ASM multicast source on an inpcb.
 1315  * This implements the delta-based API described in RFC 3678.
 1316  *
 1317  * The delta-based API applies only to exclusive-mode memberships.
 1318  * An MLD downcall will be performed.
 1319  *
 1320  * SMPng: NOTE: Must take Giant as a join may create a new ifma.
 1321  *
 1322  * Return 0 if successful, otherwise return an appropriate error code.
 1323  */
 1324 static int
 1325 in6p_block_unblock_source(struct inpcb *inp, struct sockopt *sopt)
 1326 {
 1327         struct group_source_req          gsr;
 1328         sockunion_t                     *gsa, *ssa;
 1329         struct ifnet                    *ifp;
 1330         struct in6_mfilter              *imf;
 1331         struct ip6_moptions             *imo;
 1332         struct in6_msource              *ims;
 1333         struct in6_multi                        *inm;
 1334         size_t                           idx;
 1335         uint16_t                         fmode;
 1336         int                              error, doblock;
 1337 #ifdef KTR
 1338         char                             ip6tbuf[INET6_ADDRSTRLEN];
 1339 #endif
 1340 
 1341         ifp = NULL;
 1342         error = 0;
 1343         doblock = 0;
 1344 
 1345         memset(&gsr, 0, sizeof(struct group_source_req));
 1346         gsa = (sockunion_t *)&gsr.gsr_group;
 1347         ssa = (sockunion_t *)&gsr.gsr_source;
 1348 
 1349         switch (sopt->sopt_name) {
 1350         case MCAST_BLOCK_SOURCE:
 1351         case MCAST_UNBLOCK_SOURCE:
 1352                 error = sooptcopyin(sopt, &gsr,
 1353                     sizeof(struct group_source_req),
 1354                     sizeof(struct group_source_req));
 1355                 if (error)
 1356                         return (error);
 1357 
 1358                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1359                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1360                         return (EINVAL);
 1361 
 1362                 if (ssa->sin6.sin6_family != AF_INET6 ||
 1363                     ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1364                         return (EINVAL);
 1365 
 1366                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1367                         return (EADDRNOTAVAIL);
 1368 
 1369                 ifp = ifnet_byindex(gsr.gsr_interface);
 1370 
 1371                 if (sopt->sopt_name == MCAST_BLOCK_SOURCE)
 1372                         doblock = 1;
 1373                 break;
 1374 
 1375         default:
 1376                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1377                     __func__, sopt->sopt_name);
 1378                 return (EOPNOTSUPP);
 1379                 break;
 1380         }
 1381 
 1382         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1383                 return (EINVAL);
 1384 
 1385         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1386 
 1387         /*
 1388          * Check if we are actually a member of this group.
 1389          */
 1390         imo = in6p_findmoptions(inp);
 1391         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1392         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1393                 error = EADDRNOTAVAIL;
 1394                 goto out_in6p_locked;
 1395         }
 1396 
 1397         KASSERT(imo->im6o_mfilters != NULL,
 1398             ("%s: im6o_mfilters not allocated", __func__));
 1399         imf = &imo->im6o_mfilters[idx];
 1400         inm = imo->im6o_membership[idx];
 1401 
 1402         /*
 1403          * Attempting to use the delta-based API on an
 1404          * non exclusive-mode membership is an error.
 1405          */
 1406         fmode = imf->im6f_st[0];
 1407         if (fmode != MCAST_EXCLUDE) {
 1408                 error = EINVAL;
 1409                 goto out_in6p_locked;
 1410         }
 1411 
 1412         /*
 1413          * Deal with error cases up-front:
 1414          *  Asked to block, but already blocked; or
 1415          *  Asked to unblock, but nothing to unblock.
 1416          * If adding a new block entry, allocate it.
 1417          */
 1418         ims = im6o_match_source(imo, idx, &ssa->sa);
 1419         if ((ims != NULL && doblock) || (ims == NULL && !doblock)) {
 1420                 CTR3(KTR_MLD, "%s: source %s %spresent", __func__,
 1421                     ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 1422                     doblock ? "" : "not ");
 1423                 error = EADDRNOTAVAIL;
 1424                 goto out_in6p_locked;
 1425         }
 1426 
 1427         INP_WLOCK_ASSERT(inp);
 1428 
 1429         /*
 1430          * Begin state merge transaction at socket layer.
 1431          */
 1432         if (doblock) {
 1433                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 1434                 ims = im6f_graft(imf, fmode, &ssa->sin6);
 1435                 if (ims == NULL)
 1436                         error = ENOMEM;
 1437         } else {
 1438                 CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 1439                 error = im6f_prune(imf, &ssa->sin6);
 1440         }
 1441 
 1442         if (error) {
 1443                 CTR1(KTR_MLD, "%s: merge imf state failed", __func__);
 1444                 goto out_im6f_rollback;
 1445         }
 1446 
 1447         /*
 1448          * Begin state merge transaction at MLD layer.
 1449          */
 1450         IN6_MULTI_LOCK();
 1451 
 1452         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1453         error = in6m_merge(inm, imf);
 1454         if (error)
 1455                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1456         else {
 1457                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1458                 error = mld_change_state(inm, 0);
 1459                 if (error)
 1460                         CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1461         }
 1462 
 1463         IN6_MULTI_UNLOCK();
 1464 
 1465 out_im6f_rollback:
 1466         if (error)
 1467                 im6f_rollback(imf);
 1468         else
 1469                 im6f_commit(imf);
 1470 
 1471         im6f_reap(imf);
 1472 
 1473 out_in6p_locked:
 1474         INP_WUNLOCK(inp);
 1475         return (error);
 1476 }
 1477 
 1478 /*
 1479  * Given an inpcb, return its multicast options structure pointer.  Accepts
 1480  * an unlocked inpcb pointer, but will return it locked.  May sleep.
 1481  *
 1482  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 1483  * SMPng: NOTE: Returns with the INP write lock held.
 1484  */
 1485 static struct ip6_moptions *
 1486 in6p_findmoptions(struct inpcb *inp)
 1487 {
 1488         struct ip6_moptions      *imo;
 1489         struct in6_multi                **immp;
 1490         struct in6_mfilter       *imfp;
 1491         size_t                    idx;
 1492 
 1493         INP_WLOCK(inp);
 1494         if (inp->in6p_moptions != NULL)
 1495                 return (inp->in6p_moptions);
 1496 
 1497         INP_WUNLOCK(inp);
 1498 
 1499         imo = malloc(sizeof(*imo), M_IP6MOPTS, M_WAITOK);
 1500         immp = malloc(sizeof(*immp) * IPV6_MIN_MEMBERSHIPS, M_IP6MOPTS,
 1501             M_WAITOK | M_ZERO);
 1502         imfp = malloc(sizeof(struct in6_mfilter) * IPV6_MIN_MEMBERSHIPS,
 1503             M_IN6MFILTER, M_WAITOK);
 1504 
 1505         imo->im6o_multicast_ifp = NULL;
 1506         imo->im6o_multicast_hlim = V_ip6_defmcasthlim;
 1507         imo->im6o_multicast_loop = in6_mcast_loop;
 1508         imo->im6o_num_memberships = 0;
 1509         imo->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
 1510         imo->im6o_membership = immp;
 1511 
 1512         /* Initialize per-group source filters. */
 1513         for (idx = 0; idx < IPV6_MIN_MEMBERSHIPS; idx++)
 1514                 im6f_init(&imfp[idx], MCAST_UNDEFINED, MCAST_EXCLUDE);
 1515         imo->im6o_mfilters = imfp;
 1516 
 1517         INP_WLOCK(inp);
 1518         if (inp->in6p_moptions != NULL) {
 1519                 free(imfp, M_IN6MFILTER);
 1520                 free(immp, M_IP6MOPTS);
 1521                 free(imo, M_IP6MOPTS);
 1522                 return (inp->in6p_moptions);
 1523         }
 1524         inp->in6p_moptions = imo;
 1525         return (imo);
 1526 }
 1527 
 1528 /*
 1529  * Discard the IPv6 multicast options (and source filters).
 1530  *
 1531  * SMPng: NOTE: assumes INP write lock is held.
 1532  */
 1533 void
 1534 ip6_freemoptions(struct ip6_moptions *imo)
 1535 {
 1536         struct in6_mfilter      *imf;
 1537         size_t                   idx, nmships;
 1538 
 1539         KASSERT(imo != NULL, ("%s: ip6_moptions is NULL", __func__));
 1540 
 1541         nmships = imo->im6o_num_memberships;
 1542         for (idx = 0; idx < nmships; ++idx) {
 1543                 imf = imo->im6o_mfilters ? &imo->im6o_mfilters[idx] : NULL;
 1544                 if (imf)
 1545                         im6f_leave(imf);
 1546                 /* XXX this will thrash the lock(s) */
 1547                 (void)in6_mc_leave(imo->im6o_membership[idx], imf);
 1548                 if (imf)
 1549                         im6f_purge(imf);
 1550         }
 1551 
 1552         if (imo->im6o_mfilters)
 1553                 free(imo->im6o_mfilters, M_IN6MFILTER);
 1554         free(imo->im6o_membership, M_IP6MOPTS);
 1555         free(imo, M_IP6MOPTS);
 1556 }
 1557 
 1558 /*
 1559  * Atomically get source filters on a socket for an IPv6 multicast group.
 1560  * Called with INP lock held; returns with lock released.
 1561  */
 1562 static int
 1563 in6p_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
 1564 {
 1565         struct __msfilterreq     msfr;
 1566         sockunion_t             *gsa;
 1567         struct ifnet            *ifp;
 1568         struct ip6_moptions     *imo;
 1569         struct in6_mfilter      *imf;
 1570         struct ip6_msource      *ims;
 1571         struct in6_msource      *lims;
 1572         struct sockaddr_in6     *psin;
 1573         struct sockaddr_storage *ptss;
 1574         struct sockaddr_storage *tss;
 1575         int                      error;
 1576         size_t                   idx, nsrcs, ncsrcs;
 1577 
 1578         INP_WLOCK_ASSERT(inp);
 1579 
 1580         imo = inp->in6p_moptions;
 1581         KASSERT(imo != NULL, ("%s: null ip6_moptions", __func__));
 1582 
 1583         INP_WUNLOCK(inp);
 1584 
 1585         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 1586             sizeof(struct __msfilterreq));
 1587         if (error)
 1588                 return (error);
 1589 
 1590         if (msfr.msfr_group.ss_family != AF_INET6 ||
 1591             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 1592                 return (EINVAL);
 1593 
 1594         gsa = (sockunion_t *)&msfr.msfr_group;
 1595         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1596                 return (EINVAL);
 1597 
 1598         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 1599                 return (EADDRNOTAVAIL);
 1600         ifp = ifnet_byindex(msfr.msfr_ifindex);
 1601         if (ifp == NULL)
 1602                 return (EADDRNOTAVAIL);
 1603         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1604 
 1605         INP_WLOCK(inp);
 1606 
 1607         /*
 1608          * Lookup group on the socket.
 1609          */
 1610         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1611         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1612                 INP_WUNLOCK(inp);
 1613                 return (EADDRNOTAVAIL);
 1614         }
 1615         imf = &imo->im6o_mfilters[idx];
 1616 
 1617         /*
 1618          * Ignore memberships which are in limbo.
 1619          */
 1620         if (imf->im6f_st[1] == MCAST_UNDEFINED) {
 1621                 INP_WUNLOCK(inp);
 1622                 return (EAGAIN);
 1623         }
 1624         msfr.msfr_fmode = imf->im6f_st[1];
 1625 
 1626         /*
 1627          * If the user specified a buffer, copy out the source filter
 1628          * entries to userland gracefully.
 1629          * We only copy out the number of entries which userland
 1630          * has asked for, but we always tell userland how big the
 1631          * buffer really needs to be.
 1632          */
 1633         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 1634                 msfr.msfr_nsrcs = in6_mcast_maxsocksrc;
 1635         tss = NULL;
 1636         if (msfr.msfr_srcs != NULL && msfr.msfr_nsrcs > 0) {
 1637                 tss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 1638                     M_TEMP, M_NOWAIT | M_ZERO);
 1639                 if (tss == NULL) {
 1640                         INP_WUNLOCK(inp);
 1641                         return (ENOBUFS);
 1642                 }
 1643         }
 1644 
 1645         /*
 1646          * Count number of sources in-mode at t0.
 1647          * If buffer space exists and remains, copy out source entries.
 1648          */
 1649         nsrcs = msfr.msfr_nsrcs;
 1650         ncsrcs = 0;
 1651         ptss = tss;
 1652         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
 1653                 lims = (struct in6_msource *)ims;
 1654                 if (lims->im6sl_st[0] == MCAST_UNDEFINED ||
 1655                     lims->im6sl_st[0] != imf->im6f_st[0])
 1656                         continue;
 1657                 ++ncsrcs;
 1658                 if (tss != NULL && nsrcs > 0) {
 1659                         psin = (struct sockaddr_in6 *)ptss;
 1660                         psin->sin6_family = AF_INET6;
 1661                         psin->sin6_len = sizeof(struct sockaddr_in6);
 1662                         psin->sin6_addr = lims->im6s_addr;
 1663                         psin->sin6_port = 0;
 1664                         --nsrcs;
 1665                         ++ptss;
 1666                 }
 1667         }
 1668 
 1669         INP_WUNLOCK(inp);
 1670 
 1671         if (tss != NULL) {
 1672                 error = copyout(tss, msfr.msfr_srcs,
 1673                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 1674                 free(tss, M_TEMP);
 1675                 if (error)
 1676                         return (error);
 1677         }
 1678 
 1679         msfr.msfr_nsrcs = ncsrcs;
 1680         error = sooptcopyout(sopt, &msfr, sizeof(struct __msfilterreq));
 1681 
 1682         return (error);
 1683 }
 1684 
 1685 /*
 1686  * Return the IP multicast options in response to user getsockopt().
 1687  */
 1688 int
 1689 ip6_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 1690 {
 1691         struct ip6_moptions     *im6o;
 1692         int                      error;
 1693         u_int                    optval;
 1694 
 1695         INP_WLOCK(inp);
 1696         im6o = inp->in6p_moptions;
 1697         /*
 1698          * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 1699          * or is a divert socket, reject it.
 1700          */
 1701         if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
 1702             (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
 1703             inp->inp_socket->so_proto->pr_type != SOCK_DGRAM)) {
 1704                 INP_WUNLOCK(inp);
 1705                 return (EOPNOTSUPP);
 1706         }
 1707 
 1708         error = 0;
 1709         switch (sopt->sopt_name) {
 1710         case IPV6_MULTICAST_IF:
 1711                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL) {
 1712                         optval = 0;
 1713                 } else {
 1714                         optval = im6o->im6o_multicast_ifp->if_index;
 1715                 }
 1716                 INP_WUNLOCK(inp);
 1717                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1718                 break;
 1719 
 1720         case IPV6_MULTICAST_HOPS:
 1721                 if (im6o == NULL)
 1722                         optval = V_ip6_defmcasthlim;
 1723                 else
 1724                         optval = im6o->im6o_multicast_hlim;
 1725                 INP_WUNLOCK(inp);
 1726                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1727                 break;
 1728 
 1729         case IPV6_MULTICAST_LOOP:
 1730                 if (im6o == NULL)
 1731                         optval = in6_mcast_loop; /* XXX VIMAGE */
 1732                 else
 1733                         optval = im6o->im6o_multicast_loop;
 1734                 INP_WUNLOCK(inp);
 1735                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1736                 break;
 1737 
 1738         case IPV6_MSFILTER:
 1739                 if (im6o == NULL) {
 1740                         error = EADDRNOTAVAIL;
 1741                         INP_WUNLOCK(inp);
 1742                 } else {
 1743                         error = in6p_get_source_filters(inp, sopt);
 1744                 }
 1745                 break;
 1746 
 1747         default:
 1748                 INP_WUNLOCK(inp);
 1749                 error = ENOPROTOOPT;
 1750                 break;
 1751         }
 1752 
 1753         INP_UNLOCK_ASSERT(inp);
 1754 
 1755         return (error);
 1756 }
 1757 
 1758 /*
 1759  * Look up the ifnet to use for a multicast group membership,
 1760  * given the address of an IPv6 group.
 1761  *
 1762  * This routine exists to support legacy IPv6 multicast applications.
 1763  *
 1764  * If inp is non-NULL, use this socket's current FIB number for any
 1765  * required FIB lookup. Look up the group address in the unicast FIB,
 1766  * and use its ifp; usually, this points to the default next-hop.
 1767  * If the FIB lookup fails, return NULL.
 1768  *
 1769  * FUTURE: Support multiple forwarding tables for IPv6.
 1770  *
 1771  * Returns NULL if no ifp could be found.
 1772  */
 1773 static struct ifnet *
 1774 in6p_lookup_mcast_ifp(const struct inpcb *in6p,
 1775     const struct sockaddr_in6 *gsin6)
 1776 {
 1777         struct route_in6         ro6;
 1778         struct ifnet            *ifp;
 1779 
 1780         KASSERT(in6p->inp_vflag & INP_IPV6,
 1781             ("%s: not INP_IPV6 inpcb", __func__));
 1782         KASSERT(gsin6->sin6_family == AF_INET6,
 1783             ("%s: not AF_INET6 group", __func__));
 1784         KASSERT(IN6_IS_ADDR_MULTICAST(&gsin6->sin6_addr),
 1785             ("%s: not multicast", __func__));
 1786 
 1787         ifp = NULL;
 1788         memset(&ro6, 0, sizeof(struct route_in6));
 1789         memcpy(&ro6.ro_dst, gsin6, sizeof(struct sockaddr_in6));
 1790         rtalloc_ign_fib((struct route *)&ro6, 0,
 1791             in6p ? in6p->inp_inc.inc_fibnum : RT_DEFAULT_FIB);
 1792         if (ro6.ro_rt != NULL) {
 1793                 ifp = ro6.ro_rt->rt_ifp;
 1794                 KASSERT(ifp != NULL, ("%s: null ifp", __func__));
 1795                 RTFREE(ro6.ro_rt);
 1796         }
 1797 
 1798         return (ifp);
 1799 }
 1800 
 1801 /*
 1802  * Join an IPv6 multicast group, possibly with a source.
 1803  *
 1804  * FIXME: The KAME use of the unspecified address (::)
 1805  * to join *all* multicast groups is currently unsupported.
 1806  */
 1807 static int
 1808 in6p_join_group(struct inpcb *inp, struct sockopt *sopt)
 1809 {
 1810         struct group_source_req          gsr;
 1811         sockunion_t                     *gsa, *ssa;
 1812         struct ifnet                    *ifp;
 1813         struct in6_mfilter              *imf;
 1814         struct ip6_moptions             *imo;
 1815         struct in6_multi                *inm;
 1816         struct in6_msource              *lims;
 1817         size_t                           idx;
 1818         int                              error, is_new;
 1819 
 1820         ifp = NULL;
 1821         imf = NULL;
 1822         lims = NULL;
 1823         error = 0;
 1824         is_new = 0;
 1825 
 1826         memset(&gsr, 0, sizeof(struct group_source_req));
 1827         gsa = (sockunion_t *)&gsr.gsr_group;
 1828         gsa->ss.ss_family = AF_UNSPEC;
 1829         ssa = (sockunion_t *)&gsr.gsr_source;
 1830         ssa->ss.ss_family = AF_UNSPEC;
 1831 
 1832         /*
 1833          * Chew everything into struct group_source_req.
 1834          * Overwrite the port field if present, as the sockaddr
 1835          * being copied in may be matched with a binary comparison.
 1836          * Ignore passed-in scope ID.
 1837          */
 1838         switch (sopt->sopt_name) {
 1839         case IPV6_JOIN_GROUP: {
 1840                 struct ipv6_mreq mreq;
 1841 
 1842                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 1843                     sizeof(struct ipv6_mreq));
 1844                 if (error)
 1845                         return (error);
 1846 
 1847                 gsa->sin6.sin6_family = AF_INET6;
 1848                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 1849                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 1850 
 1851                 if (mreq.ipv6mr_interface == 0) {
 1852                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 1853                 } else {
 1854                         if (mreq.ipv6mr_interface < 0 ||
 1855                             V_if_index < mreq.ipv6mr_interface)
 1856                                 return (EADDRNOTAVAIL);
 1857                         ifp = ifnet_byindex(mreq.ipv6mr_interface);
 1858                 }
 1859                 CTR3(KTR_MLD, "%s: ipv6mr_interface = %d, ifp = %p",
 1860                     __func__, mreq.ipv6mr_interface, ifp);
 1861         } break;
 1862 
 1863         case MCAST_JOIN_GROUP:
 1864         case MCAST_JOIN_SOURCE_GROUP:
 1865                 if (sopt->sopt_name == MCAST_JOIN_GROUP) {
 1866                         error = sooptcopyin(sopt, &gsr,
 1867                             sizeof(struct group_req),
 1868                             sizeof(struct group_req));
 1869                 } else if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1870                         error = sooptcopyin(sopt, &gsr,
 1871                             sizeof(struct group_source_req),
 1872                             sizeof(struct group_source_req));
 1873                 }
 1874                 if (error)
 1875                         return (error);
 1876 
 1877                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1878                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1879                         return (EINVAL);
 1880 
 1881                 if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1882                         if (ssa->sin6.sin6_family != AF_INET6 ||
 1883                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1884                                 return (EINVAL);
 1885                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 1886                                 return (EINVAL);
 1887                         /*
 1888                          * TODO: Validate embedded scope ID in source
 1889                          * list entry against passed-in ifp, if and only
 1890                          * if source list filter entry is iface or node local.
 1891                          */
 1892                         in6_clearscope(&ssa->sin6.sin6_addr);
 1893                         ssa->sin6.sin6_port = 0;
 1894                         ssa->sin6.sin6_scope_id = 0;
 1895                 }
 1896 
 1897                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1898                         return (EADDRNOTAVAIL);
 1899                 ifp = ifnet_byindex(gsr.gsr_interface);
 1900                 break;
 1901 
 1902         default:
 1903                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1904                     __func__, sopt->sopt_name);
 1905                 return (EOPNOTSUPP);
 1906                 break;
 1907         }
 1908 
 1909         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1910                 return (EINVAL);
 1911 
 1912         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
 1913                 return (EADDRNOTAVAIL);
 1914 
 1915         gsa->sin6.sin6_port = 0;
 1916         gsa->sin6.sin6_scope_id = 0;
 1917 
 1918         /*
 1919          * Always set the scope zone ID on memberships created from userland.
 1920          * Use the passed-in ifp to do this.
 1921          * XXX The in6_setscope() return value is meaningless.
 1922          * XXX SCOPE6_LOCK() is taken by in6_setscope().
 1923          */
 1924         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1925 
 1926         imo = in6p_findmoptions(inp);
 1927         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1928         if (idx == -1) {
 1929                 is_new = 1;
 1930         } else {
 1931                 inm = imo->im6o_membership[idx];
 1932                 imf = &imo->im6o_mfilters[idx];
 1933                 if (ssa->ss.ss_family != AF_UNSPEC) {
 1934                         /*
 1935                          * MCAST_JOIN_SOURCE_GROUP on an exclusive membership
 1936                          * is an error. On an existing inclusive membership,
 1937                          * it just adds the source to the filter list.
 1938                          */
 1939                         if (imf->im6f_st[1] != MCAST_INCLUDE) {
 1940                                 error = EINVAL;
 1941                                 goto out_in6p_locked;
 1942                         }
 1943                         /*
 1944                          * Throw out duplicates.
 1945                          *
 1946                          * XXX FIXME: This makes a naive assumption that
 1947                          * even if entries exist for *ssa in this imf,
 1948                          * they will be rejected as dupes, even if they
 1949                          * are not valid in the current mode (in-mode).
 1950                          *
 1951                          * in6_msource is transactioned just as for anything
 1952                          * else in SSM -- but note naive use of in6m_graft()
 1953                          * below for allocating new filter entries.
 1954                          *
 1955                          * This is only an issue if someone mixes the
 1956                          * full-state SSM API with the delta-based API,
 1957                          * which is discouraged in the relevant RFCs.
 1958                          */
 1959                         lims = im6o_match_source(imo, idx, &ssa->sa);
 1960                         if (lims != NULL /*&&
 1961                             lims->im6sl_st[1] == MCAST_INCLUDE*/) {
 1962                                 error = EADDRNOTAVAIL;
 1963                                 goto out_in6p_locked;
 1964                         }
 1965                 } else {
 1966                         /*
 1967                          * MCAST_JOIN_GROUP alone, on any existing membership,
 1968                          * is rejected, to stop the same inpcb tying up
 1969                          * multiple refs to the in_multi.
 1970                          * On an existing inclusive membership, this is also
 1971                          * an error; if you want to change filter mode,
 1972                          * you must use the userland API setsourcefilter().
 1973                          * XXX We don't reject this for imf in UNDEFINED
 1974                          * state at t1, because allocation of a filter
 1975                          * is atomic with allocation of a membership.
 1976                          */
 1977                         error = EINVAL;
 1978                         goto out_in6p_locked;
 1979                 }
 1980         }
 1981 
 1982         /*
 1983          * Begin state merge transaction at socket layer.
 1984          */
 1985         INP_WLOCK_ASSERT(inp);
 1986 
 1987         if (is_new) {
 1988                 if (imo->im6o_num_memberships == imo->im6o_max_memberships) {
 1989                         error = im6o_grow(imo);
 1990                         if (error)
 1991                                 goto out_in6p_locked;
 1992                 }
 1993                 /*
 1994                  * Allocate the new slot upfront so we can deal with
 1995                  * grafting the new source filter in same code path
 1996                  * as for join-source on existing membership.
 1997                  */
 1998                 idx = imo->im6o_num_memberships;
 1999                 imo->im6o_membership[idx] = NULL;
 2000                 imo->im6o_num_memberships++;
 2001                 KASSERT(imo->im6o_mfilters != NULL,
 2002                     ("%s: im6f_mfilters vector was not allocated", __func__));
 2003                 imf = &imo->im6o_mfilters[idx];
 2004                 KASSERT(RB_EMPTY(&imf->im6f_sources),
 2005                     ("%s: im6f_sources not empty", __func__));
 2006         }
 2007 
 2008         /*
 2009          * Graft new source into filter list for this inpcb's
 2010          * membership of the group. The in6_multi may not have
 2011          * been allocated yet if this is a new membership, however,
 2012          * the in_mfilter slot will be allocated and must be initialized.
 2013          *
 2014          * Note: Grafting of exclusive mode filters doesn't happen
 2015          * in this path.
 2016          * XXX: Should check for non-NULL lims (node exists but may
 2017          * not be in-mode) for interop with full-state API.
 2018          */
 2019         if (ssa->ss.ss_family != AF_UNSPEC) {
 2020                 /* Membership starts in IN mode */
 2021                 if (is_new) {
 2022                         CTR1(KTR_MLD, "%s: new join w/source", __func__);
 2023                         im6f_init(imf, MCAST_UNDEFINED, MCAST_INCLUDE);
 2024                 } else {
 2025                         CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 2026                 }
 2027                 lims = im6f_graft(imf, MCAST_INCLUDE, &ssa->sin6);
 2028                 if (lims == NULL) {
 2029                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2030                             __func__);
 2031                         error = ENOMEM;
 2032                         goto out_im6o_free;
 2033                 }
 2034         } else {
 2035                 /* No address specified; Membership starts in EX mode */
 2036                 if (is_new) {
 2037                         CTR1(KTR_MLD, "%s: new join w/o source", __func__);
 2038                         im6f_init(imf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 2039                 }
 2040         }
 2041 
 2042         /*
 2043          * Begin state merge transaction at MLD layer.
 2044          */
 2045         IN6_MULTI_LOCK();
 2046 
 2047         if (is_new) {
 2048                 error = in6_mc_join_locked(ifp, &gsa->sin6.sin6_addr, imf,
 2049                     &inm, 0);
 2050                 if (error) {
 2051                         IN6_MULTI_UNLOCK();
 2052                         goto out_im6o_free;
 2053                 }
 2054                 imo->im6o_membership[idx] = inm;
 2055         } else {
 2056                 CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2057                 error = in6m_merge(inm, imf);
 2058                 if (error)
 2059                         CTR1(KTR_MLD, "%s: failed to merge inm state",
 2060                             __func__);
 2061                 else {
 2062                         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2063                         error = mld_change_state(inm, 0);
 2064                         if (error)
 2065                                 CTR1(KTR_MLD, "%s: failed mld downcall",
 2066                                     __func__);
 2067                 }
 2068         }
 2069 
 2070         IN6_MULTI_UNLOCK();
 2071         INP_WLOCK_ASSERT(inp);
 2072         if (error) {
 2073                 im6f_rollback(imf);
 2074                 if (is_new)
 2075                         im6f_purge(imf);
 2076                 else
 2077                         im6f_reap(imf);
 2078         } else {
 2079                 im6f_commit(imf);
 2080         }
 2081 
 2082 out_im6o_free:
 2083         if (error && is_new) {
 2084                 imo->im6o_membership[idx] = NULL;
 2085                 --imo->im6o_num_memberships;
 2086         }
 2087 
 2088 out_in6p_locked:
 2089         INP_WUNLOCK(inp);
 2090         return (error);
 2091 }
 2092 
 2093 /*
 2094  * Leave an IPv6 multicast group on an inpcb, possibly with a source.
 2095  */
 2096 static int
 2097 in6p_leave_group(struct inpcb *inp, struct sockopt *sopt)
 2098 {
 2099         struct ipv6_mreq                 mreq;
 2100         struct group_source_req          gsr;
 2101         sockunion_t                     *gsa, *ssa;
 2102         struct ifnet                    *ifp;
 2103         struct in6_mfilter              *imf;
 2104         struct ip6_moptions             *imo;
 2105         struct in6_msource              *ims;
 2106         struct in6_multi                *inm;
 2107         uint32_t                         ifindex;
 2108         size_t                           idx;
 2109         int                              error, is_final;
 2110 #ifdef KTR
 2111         char                             ip6tbuf[INET6_ADDRSTRLEN];
 2112 #endif
 2113 
 2114         ifp = NULL;
 2115         ifindex = 0;
 2116         error = 0;
 2117         is_final = 1;
 2118 
 2119         memset(&gsr, 0, sizeof(struct group_source_req));
 2120         gsa = (sockunion_t *)&gsr.gsr_group;
 2121         gsa->ss.ss_family = AF_UNSPEC;
 2122         ssa = (sockunion_t *)&gsr.gsr_source;
 2123         ssa->ss.ss_family = AF_UNSPEC;
 2124 
 2125         /*
 2126          * Chew everything passed in up into a struct group_source_req
 2127          * as that is easier to process.
 2128          * Note: Any embedded scope ID in the multicast group passed
 2129          * in by userland is ignored, the interface index is the recommended
 2130          * mechanism to specify an interface; see below.
 2131          */
 2132         switch (sopt->sopt_name) {
 2133         case IPV6_LEAVE_GROUP:
 2134                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 2135                     sizeof(struct ipv6_mreq));
 2136                 if (error)
 2137                         return (error);
 2138                 gsa->sin6.sin6_family = AF_INET6;
 2139                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 2140                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 2141                 gsa->sin6.sin6_port = 0;
 2142                 gsa->sin6.sin6_scope_id = 0;
 2143                 ifindex = mreq.ipv6mr_interface;
 2144                 break;
 2145 
 2146         case MCAST_LEAVE_GROUP:
 2147         case MCAST_LEAVE_SOURCE_GROUP:
 2148                 if (sopt->sopt_name == MCAST_LEAVE_GROUP) {
 2149                         error = sooptcopyin(sopt, &gsr,
 2150                             sizeof(struct group_req),
 2151                             sizeof(struct group_req));
 2152                 } else if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2153                         error = sooptcopyin(sopt, &gsr,
 2154                             sizeof(struct group_source_req),
 2155                             sizeof(struct group_source_req));
 2156                 }
 2157                 if (error)
 2158                         return (error);
 2159 
 2160                 if (gsa->sin6.sin6_family != AF_INET6 ||
 2161                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2162                         return (EINVAL);
 2163                 if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2164                         if (ssa->sin6.sin6_family != AF_INET6 ||
 2165                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2166                                 return (EINVAL);
 2167                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 2168                                 return (EINVAL);
 2169                         /*
 2170                          * TODO: Validate embedded scope ID in source
 2171                          * list entry against passed-in ifp, if and only
 2172                          * if source list filter entry is iface or node local.
 2173                          */
 2174                         in6_clearscope(&ssa->sin6.sin6_addr);
 2175                 }
 2176                 gsa->sin6.sin6_port = 0;
 2177                 gsa->sin6.sin6_scope_id = 0;
 2178                 ifindex = gsr.gsr_interface;
 2179                 break;
 2180 
 2181         default:
 2182                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 2183                     __func__, sopt->sopt_name);
 2184                 return (EOPNOTSUPP);
 2185                 break;
 2186         }
 2187 
 2188         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2189                 return (EINVAL);
 2190 
 2191         /*
 2192          * Validate interface index if provided. If no interface index
 2193          * was provided separately, attempt to look the membership up
 2194          * from the default scope as a last resort to disambiguate
 2195          * the membership we are being asked to leave.
 2196          * XXX SCOPE6 lock potentially taken here.
 2197          */
 2198         if (ifindex != 0) {
 2199                 if (ifindex < 0 || V_if_index < ifindex)
 2200                         return (EADDRNOTAVAIL);
 2201                 ifp = ifnet_byindex(ifindex);
 2202                 if (ifp == NULL)
 2203                         return (EADDRNOTAVAIL);
 2204                 (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2205         } else {
 2206                 error = sa6_embedscope(&gsa->sin6, V_ip6_use_defzone);
 2207                 if (error)
 2208                         return (EADDRNOTAVAIL);
 2209                 /*
 2210                  * Some badly behaved applications don't pass an ifindex
 2211                  * or a scope ID, which is an API violation. In this case,
 2212                  * perform a lookup as per a v6 join.
 2213                  *
 2214                  * XXX For now, stomp on zone ID for the corner case.
 2215                  * This is not the 'KAME way', but we need to see the ifp
 2216                  * directly until such time as this implementation is
 2217                  * refactored, assuming the scope IDs are the way to go.
 2218                  */
 2219                 ifindex = ntohs(gsa->sin6.sin6_addr.s6_addr16[1]);
 2220                 if (ifindex == 0) {
 2221                         CTR2(KTR_MLD, "%s: warning: no ifindex, looking up "
 2222                             "ifp for group %s.", __func__,
 2223                             ip6_sprintf(ip6tbuf, &gsa->sin6.sin6_addr));
 2224                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 2225                 } else {
 2226                         ifp = ifnet_byindex(ifindex);
 2227                 }
 2228                 if (ifp == NULL)
 2229                         return (EADDRNOTAVAIL);
 2230         }
 2231 
 2232         CTR2(KTR_MLD, "%s: ifp = %p", __func__, ifp);
 2233         KASSERT(ifp != NULL, ("%s: ifp did not resolve", __func__));
 2234 
 2235         /*
 2236          * Find the membership in the membership array.
 2237          */
 2238         imo = in6p_findmoptions(inp);
 2239         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2240         if (idx == -1) {
 2241                 error = EADDRNOTAVAIL;
 2242                 goto out_in6p_locked;
 2243         }
 2244         inm = imo->im6o_membership[idx];
 2245         imf = &imo->im6o_mfilters[idx];
 2246 
 2247         if (ssa->ss.ss_family != AF_UNSPEC)
 2248                 is_final = 0;
 2249 
 2250         /*
 2251          * Begin state merge transaction at socket layer.
 2252          */
 2253         INP_WLOCK_ASSERT(inp);
 2254 
 2255         /*
 2256          * If we were instructed only to leave a given source, do so.
 2257          * MCAST_LEAVE_SOURCE_GROUP is only valid for inclusive memberships.
 2258          */
 2259         if (is_final) {
 2260                 im6f_leave(imf);
 2261         } else {
 2262                 if (imf->im6f_st[0] == MCAST_EXCLUDE) {
 2263                         error = EADDRNOTAVAIL;
 2264                         goto out_in6p_locked;
 2265                 }
 2266                 ims = im6o_match_source(imo, idx, &ssa->sa);
 2267                 if (ims == NULL) {
 2268                         CTR3(KTR_MLD, "%s: source %p %spresent", __func__,
 2269                             ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 2270                             "not ");
 2271                         error = EADDRNOTAVAIL;
 2272                         goto out_in6p_locked;
 2273                 }
 2274                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 2275                 error = im6f_prune(imf, &ssa->sin6);
 2276                 if (error) {
 2277                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2278                             __func__);
 2279                         goto out_in6p_locked;
 2280                 }
 2281         }
 2282 
 2283         /*
 2284          * Begin state merge transaction at MLD layer.
 2285          */
 2286         IN6_MULTI_LOCK();
 2287 
 2288         if (is_final) {
 2289                 /*
 2290                  * Give up the multicast address record to which
 2291                  * the membership points.
 2292                  */
 2293                 (void)in6_mc_leave_locked(inm, imf);
 2294         } else {
 2295                 CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2296                 error = in6m_merge(inm, imf);
 2297                 if (error)
 2298                         CTR1(KTR_MLD, "%s: failed to merge inm state",
 2299                             __func__);
 2300                 else {
 2301                         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2302                         error = mld_change_state(inm, 0);
 2303                         if (error)
 2304                                 CTR1(KTR_MLD, "%s: failed mld downcall",
 2305                                     __func__);
 2306                 }
 2307         }
 2308 
 2309         IN6_MULTI_UNLOCK();
 2310 
 2311         if (error)
 2312                 im6f_rollback(imf);
 2313         else
 2314                 im6f_commit(imf);
 2315 
 2316         im6f_reap(imf);
 2317 
 2318         if (is_final) {
 2319                 /* Remove the gap in the membership array. */
 2320                 for (++idx; idx < imo->im6o_num_memberships; ++idx) {
 2321                         imo->im6o_membership[idx-1] = imo->im6o_membership[idx];
 2322                         imo->im6o_mfilters[idx-1] = imo->im6o_mfilters[idx];
 2323                 }
 2324                 imo->im6o_num_memberships--;
 2325         }
 2326 
 2327 out_in6p_locked:
 2328         INP_WUNLOCK(inp);
 2329         return (error);
 2330 }
 2331 
 2332 /*
 2333  * Select the interface for transmitting IPv6 multicast datagrams.
 2334  *
 2335  * Either an instance of struct in6_addr or an instance of struct ipv6_mreqn
 2336  * may be passed to this socket option. An address of in6addr_any or an
 2337  * interface index of 0 is used to remove a previous selection.
 2338  * When no interface is selected, one is chosen for every send.
 2339  */
 2340 static int
 2341 in6p_set_multicast_if(struct inpcb *inp, struct sockopt *sopt)
 2342 {
 2343         struct ifnet            *ifp;
 2344         struct ip6_moptions     *imo;
 2345         u_int                    ifindex;
 2346         int                      error;
 2347 
 2348         if (sopt->sopt_valsize != sizeof(u_int))
 2349                 return (EINVAL);
 2350 
 2351         error = sooptcopyin(sopt, &ifindex, sizeof(u_int), sizeof(u_int));
 2352         if (error)
 2353                 return (error);
 2354         if (ifindex < 0 || V_if_index < ifindex)
 2355                 return (EINVAL);
 2356         if (ifindex == 0)
 2357                 ifp = NULL;
 2358         else {
 2359                 ifp = ifnet_byindex(ifindex);
 2360                 if (ifp == NULL)
 2361                         return (EINVAL);
 2362                 if ((ifp->if_flags & IFF_MULTICAST) == 0)
 2363                         return (EADDRNOTAVAIL);
 2364         }
 2365         imo = in6p_findmoptions(inp);
 2366         imo->im6o_multicast_ifp = ifp;
 2367         INP_WUNLOCK(inp);
 2368 
 2369         return (0);
 2370 }
 2371 
 2372 /*
 2373  * Atomically set source filters on a socket for an IPv6 multicast group.
 2374  *
 2375  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 2376  */
 2377 static int
 2378 in6p_set_source_filters(struct inpcb *inp, struct sockopt *sopt)
 2379 {
 2380         struct __msfilterreq     msfr;
 2381         sockunion_t             *gsa;
 2382         struct ifnet            *ifp;
 2383         struct in6_mfilter      *imf;
 2384         struct ip6_moptions     *imo;
 2385         struct in6_multi                *inm;
 2386         size_t                   idx;
 2387         int                      error;
 2388 
 2389         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 2390             sizeof(struct __msfilterreq));
 2391         if (error)
 2392                 return (error);
 2393 
 2394         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 2395                 return (ENOBUFS);
 2396 
 2397         if (msfr.msfr_fmode != MCAST_EXCLUDE &&
 2398             msfr.msfr_fmode != MCAST_INCLUDE)
 2399                 return (EINVAL);
 2400 
 2401         if (msfr.msfr_group.ss_family != AF_INET6 ||
 2402             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 2403                 return (EINVAL);
 2404 
 2405         gsa = (sockunion_t *)&msfr.msfr_group;
 2406         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2407                 return (EINVAL);
 2408 
 2409         gsa->sin6.sin6_port = 0;        /* ignore port */
 2410 
 2411         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 2412                 return (EADDRNOTAVAIL);
 2413         ifp = ifnet_byindex(msfr.msfr_ifindex);
 2414         if (ifp == NULL)
 2415                 return (EADDRNOTAVAIL);
 2416         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2417 
 2418         /*
 2419          * Take the INP write lock.
 2420          * Check if this socket is a member of this group.
 2421          */
 2422         imo = in6p_findmoptions(inp);
 2423         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2424         if (idx == -1 || imo->im6o_mfilters == NULL) {
 2425                 error = EADDRNOTAVAIL;
 2426                 goto out_in6p_locked;
 2427         }
 2428         inm = imo->im6o_membership[idx];
 2429         imf = &imo->im6o_mfilters[idx];
 2430 
 2431         /*
 2432          * Begin state merge transaction at socket layer.
 2433          */
 2434         INP_WLOCK_ASSERT(inp);
 2435 
 2436         imf->im6f_st[1] = msfr.msfr_fmode;
 2437 
 2438         /*
 2439          * Apply any new source filters, if present.
 2440          * Make a copy of the user-space source vector so
 2441          * that we may copy them with a single copyin. This
 2442          * allows us to deal with page faults up-front.
 2443          */
 2444         if (msfr.msfr_nsrcs > 0) {
 2445                 struct in6_msource      *lims;
 2446                 struct sockaddr_in6     *psin;
 2447                 struct sockaddr_storage *kss, *pkss;
 2448                 int                      i;
 2449 
 2450                 INP_WUNLOCK(inp);
 2451  
 2452                 CTR2(KTR_MLD, "%s: loading %lu source list entries",
 2453                     __func__, (unsigned long)msfr.msfr_nsrcs);
 2454                 kss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 2455                     M_TEMP, M_WAITOK);
 2456                 error = copyin(msfr.msfr_srcs, kss,
 2457                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 2458                 if (error) {
 2459                         free(kss, M_TEMP);
 2460                         return (error);
 2461                 }
 2462 
 2463                 INP_WLOCK(inp);
 2464 
 2465                 /*
 2466                  * Mark all source filters as UNDEFINED at t1.
 2467                  * Restore new group filter mode, as im6f_leave()
 2468                  * will set it to INCLUDE.
 2469                  */
 2470                 im6f_leave(imf);
 2471                 imf->im6f_st[1] = msfr.msfr_fmode;
 2472 
 2473                 /*
 2474                  * Update socket layer filters at t1, lazy-allocating
 2475                  * new entries. This saves a bunch of memory at the
 2476                  * cost of one RB_FIND() per source entry; duplicate
 2477                  * entries in the msfr_nsrcs vector are ignored.
 2478                  * If we encounter an error, rollback transaction.
 2479                  *
 2480                  * XXX This too could be replaced with a set-symmetric
 2481                  * difference like loop to avoid walking from root
 2482                  * every time, as the key space is common.
 2483                  */
 2484                 for (i = 0, pkss = kss; i < msfr.msfr_nsrcs; i++, pkss++) {
 2485                         psin = (struct sockaddr_in6 *)pkss;
 2486                         if (psin->sin6_family != AF_INET6) {
 2487                                 error = EAFNOSUPPORT;
 2488                                 break;
 2489                         }
 2490                         if (psin->sin6_len != sizeof(struct sockaddr_in6)) {
 2491                                 error = EINVAL;
 2492                                 break;
 2493                         }
 2494                         if (IN6_IS_ADDR_MULTICAST(&psin->sin6_addr)) {
 2495                                 error = EINVAL;
 2496                                 break;
 2497                         }
 2498                         /*
 2499                          * TODO: Validate embedded scope ID in source
 2500                          * list entry against passed-in ifp, if and only
 2501                          * if source list filter entry is iface or node local.
 2502                          */
 2503                         in6_clearscope(&psin->sin6_addr);
 2504                         error = im6f_get_source(imf, psin, &lims);
 2505                         if (error)
 2506                                 break;
 2507                         lims->im6sl_st[1] = imf->im6f_st[1];
 2508                 }
 2509                 free(kss, M_TEMP);
 2510         }
 2511 
 2512         if (error)
 2513                 goto out_im6f_rollback;
 2514 
 2515         INP_WLOCK_ASSERT(inp);
 2516         IN6_MULTI_LOCK();
 2517 
 2518         /*
 2519          * Begin state merge transaction at MLD layer.
 2520          */
 2521         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2522         error = in6m_merge(inm, imf);
 2523         if (error)
 2524                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 2525         else {
 2526                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2527                 error = mld_change_state(inm, 0);
 2528                 if (error)
 2529                         CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 2530         }
 2531 
 2532         IN6_MULTI_UNLOCK();
 2533 
 2534 out_im6f_rollback:
 2535         if (error)
 2536                 im6f_rollback(imf);
 2537         else
 2538                 im6f_commit(imf);
 2539 
 2540         im6f_reap(imf);
 2541 
 2542 out_in6p_locked:
 2543         INP_WUNLOCK(inp);
 2544         return (error);
 2545 }
 2546 
 2547 /*
 2548  * Set the IP multicast options in response to user setsockopt().
 2549  *
 2550  * Many of the socket options handled in this function duplicate the
 2551  * functionality of socket options in the regular unicast API. However,
 2552  * it is not possible to merge the duplicate code, because the idempotence
 2553  * of the IPv6 multicast part of the BSD Sockets API must be preserved;
 2554  * the effects of these options must be treated as separate and distinct.
 2555  *
 2556  * SMPng: XXX: Unlocked read of inp_socket believed OK.
 2557  */
 2558 int
 2559 ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 2560 {
 2561         struct ip6_moptions     *im6o;
 2562         int                      error;
 2563 
 2564         error = 0;
 2565 
 2566         /*
 2567          * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 2568          * or is a divert socket, reject it.
 2569          */
 2570         if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
 2571             (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
 2572              inp->inp_socket->so_proto->pr_type != SOCK_DGRAM))
 2573                 return (EOPNOTSUPP);
 2574 
 2575         switch (sopt->sopt_name) {
 2576         case IPV6_MULTICAST_IF:
 2577                 error = in6p_set_multicast_if(inp, sopt);
 2578                 break;
 2579 
 2580         case IPV6_MULTICAST_HOPS: {
 2581                 int hlim;
 2582 
 2583                 if (sopt->sopt_valsize != sizeof(int)) {
 2584                         error = EINVAL;
 2585                         break;
 2586                 }
 2587                 error = sooptcopyin(sopt, &hlim, sizeof(hlim), sizeof(int));
 2588                 if (error)
 2589                         break;
 2590                 if (hlim < -1 || hlim > 255) {
 2591                         error = EINVAL;
 2592                         break;
 2593                 } else if (hlim == -1) {
 2594                         hlim = V_ip6_defmcasthlim;
 2595                 }
 2596                 im6o = in6p_findmoptions(inp);
 2597                 im6o->im6o_multicast_hlim = hlim;
 2598                 INP_WUNLOCK(inp);
 2599                 break;
 2600         }
 2601 
 2602         case IPV6_MULTICAST_LOOP: {
 2603                 u_int loop;
 2604 
 2605                 /*
 2606                  * Set the loopback flag for outgoing multicast packets.
 2607                  * Must be zero or one.
 2608                  */
 2609                 if (sopt->sopt_valsize != sizeof(u_int)) {
 2610                         error = EINVAL;
 2611                         break;
 2612                 }
 2613                 error = sooptcopyin(sopt, &loop, sizeof(u_int), sizeof(u_int));
 2614                 if (error)
 2615                         break;
 2616                 if (loop > 1) {
 2617                         error = EINVAL;
 2618                         break;
 2619                 }
 2620                 im6o = in6p_findmoptions(inp);
 2621                 im6o->im6o_multicast_loop = loop;
 2622                 INP_WUNLOCK(inp);
 2623                 break;
 2624         }
 2625 
 2626         case IPV6_JOIN_GROUP:
 2627         case MCAST_JOIN_GROUP:
 2628         case MCAST_JOIN_SOURCE_GROUP:
 2629                 error = in6p_join_group(inp, sopt);
 2630                 break;
 2631 
 2632         case IPV6_LEAVE_GROUP:
 2633         case MCAST_LEAVE_GROUP:
 2634         case MCAST_LEAVE_SOURCE_GROUP:
 2635                 error = in6p_leave_group(inp, sopt);
 2636                 break;
 2637 
 2638         case MCAST_BLOCK_SOURCE:
 2639         case MCAST_UNBLOCK_SOURCE:
 2640                 error = in6p_block_unblock_source(inp, sopt);
 2641                 break;
 2642 
 2643         case IPV6_MSFILTER:
 2644                 error = in6p_set_source_filters(inp, sopt);
 2645                 break;
 2646 
 2647         default:
 2648                 error = EOPNOTSUPP;
 2649                 break;
 2650         }
 2651 
 2652         INP_UNLOCK_ASSERT(inp);
 2653 
 2654         return (error);
 2655 }
 2656 
 2657 /*
 2658  * Expose MLD's multicast filter mode and source list(s) to userland,
 2659  * keyed by (ifindex, group).
 2660  * The filter mode is written out as a uint32_t, followed by
 2661  * 0..n of struct in6_addr.
 2662  * For use by ifmcstat(8).
 2663  * SMPng: NOTE: unlocked read of ifindex space.
 2664  */
 2665 static int
 2666 sysctl_ip6_mcast_filters(SYSCTL_HANDLER_ARGS)
 2667 {
 2668         struct in6_addr                  mcaddr;
 2669         struct in6_addr                  src;
 2670         struct ifnet                    *ifp;
 2671         struct ifmultiaddr              *ifma;
 2672         struct in6_multi                *inm;
 2673         struct ip6_msource              *ims;
 2674         int                             *name;
 2675         int                              retval;
 2676         u_int                            namelen;
 2677         uint32_t                         fmode, ifindex;
 2678 #ifdef KTR
 2679         char                             ip6tbuf[INET6_ADDRSTRLEN];
 2680 #endif
 2681 
 2682         name = (int *)arg1;
 2683         namelen = arg2;
 2684 
 2685         if (req->newptr != NULL)
 2686                 return (EPERM);
 2687 
 2688         /* int: ifindex + 4 * 32 bits of IPv6 address */
 2689         if (namelen != 5)
 2690                 return (EINVAL);
 2691 
 2692         ifindex = name[0];
 2693         if (ifindex <= 0 || ifindex > V_if_index) {
 2694                 CTR2(KTR_MLD, "%s: ifindex %u out of range",
 2695                     __func__, ifindex);
 2696                 return (ENOENT);
 2697         }
 2698 
 2699         memcpy(&mcaddr, &name[1], sizeof(struct in6_addr));
 2700         if (!IN6_IS_ADDR_MULTICAST(&mcaddr)) {
 2701                 CTR2(KTR_MLD, "%s: group %s is not multicast",
 2702                     __func__, ip6_sprintf(ip6tbuf, &mcaddr));
 2703                 return (EINVAL);
 2704         }
 2705 
 2706         ifp = ifnet_byindex(ifindex);
 2707         if (ifp == NULL) {
 2708                 CTR2(KTR_MLD, "%s: no ifp for ifindex %u",
 2709                     __func__, ifindex);
 2710                 return (ENOENT);
 2711         }
 2712         /*
 2713          * Internal MLD lookups require that scope/zone ID is set.
 2714          */
 2715         (void)in6_setscope(&mcaddr, ifp, NULL);
 2716 
 2717         retval = sysctl_wire_old_buffer(req,
 2718             sizeof(uint32_t) + (in6_mcast_maxgrpsrc * sizeof(struct in6_addr)));
 2719         if (retval)
 2720                 return (retval);
 2721 
 2722         IN6_MULTI_LOCK();
 2723 
 2724         IF_ADDR_RLOCK(ifp);
 2725         TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
 2726                 if (ifma->ifma_addr->sa_family != AF_INET6 ||
 2727                     ifma->ifma_protospec == NULL)
 2728                         continue;
 2729                 inm = (struct in6_multi *)ifma->ifma_protospec;
 2730                 if (!IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, &mcaddr))
 2731                         continue;
 2732                 fmode = inm->in6m_st[1].iss_fmode;
 2733                 retval = SYSCTL_OUT(req, &fmode, sizeof(uint32_t));
 2734                 if (retval != 0)
 2735                         break;
 2736                 RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
 2737                         CTR2(KTR_MLD, "%s: visit node %p", __func__, ims);
 2738                         /*
 2739                          * Only copy-out sources which are in-mode.
 2740                          */
 2741                         if (fmode != im6s_get_mode(inm, ims, 1)) {
 2742                                 CTR1(KTR_MLD, "%s: skip non-in-mode",
 2743                                     __func__);
 2744                                 continue;
 2745                         }
 2746                         src = ims->im6s_addr;
 2747                         retval = SYSCTL_OUT(req, &src,
 2748                             sizeof(struct in6_addr));
 2749                         if (retval != 0)
 2750                                 break;
 2751                 }
 2752         }
 2753         IF_ADDR_RUNLOCK(ifp);
 2754 
 2755         IN6_MULTI_UNLOCK();
 2756 
 2757         return (retval);
 2758 }
 2759 
 2760 #ifdef KTR
 2761 
 2762 static const char *in6m_modestrs[] = { "un", "in", "ex" };
 2763 
 2764 static const char *
 2765 in6m_mode_str(const int mode)
 2766 {
 2767 
 2768         if (mode >= MCAST_UNDEFINED && mode <= MCAST_EXCLUDE)
 2769                 return (in6m_modestrs[mode]);
 2770         return ("??");
 2771 }
 2772 
 2773 static const char *in6m_statestrs[] = {
 2774         "not-member",
 2775         "silent",
 2776         "idle",
 2777         "lazy",
 2778         "sleeping",
 2779         "awakening",
 2780         "query-pending",
 2781         "sg-query-pending",
 2782         "leaving"
 2783 };
 2784 
 2785 static const char *
 2786 in6m_state_str(const int state)
 2787 {
 2788 
 2789         if (state >= MLD_NOT_MEMBER && state <= MLD_LEAVING_MEMBER)
 2790                 return (in6m_statestrs[state]);
 2791         return ("??");
 2792 }
 2793 
 2794 /*
 2795  * Dump an in6_multi structure to the console.
 2796  */
 2797 void
 2798 in6m_print(const struct in6_multi *inm)
 2799 {
 2800         int t;
 2801         char ip6tbuf[INET6_ADDRSTRLEN];
 2802 
 2803         if ((ktr_mask & KTR_MLD) == 0)
 2804                 return;
 2805 
 2806         printf("%s: --- begin in6m %p ---\n", __func__, inm);
 2807         printf("addr %s ifp %p(%s) ifma %p\n",
 2808             ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2809             inm->in6m_ifp,
 2810             inm->in6m_ifp->if_xname,
 2811             inm->in6m_ifma);
 2812         printf("timer %u state %s refcount %u scq.len %u\n",
 2813             inm->in6m_timer,
 2814             in6m_state_str(inm->in6m_state),
 2815             inm->in6m_refcount,
 2816             inm->in6m_scq.ifq_len);
 2817         printf("mli %p nsrc %lu sctimer %u scrv %u\n",
 2818             inm->in6m_mli,
 2819             inm->in6m_nsrc,
 2820             inm->in6m_sctimer,
 2821             inm->in6m_scrv);
 2822         for (t = 0; t < 2; t++) {
 2823                 printf("t%d: fmode %s asm %u ex %u in %u rec %u\n", t,
 2824                     in6m_mode_str(inm->in6m_st[t].iss_fmode),
 2825                     inm->in6m_st[t].iss_asm,
 2826                     inm->in6m_st[t].iss_ex,
 2827                     inm->in6m_st[t].iss_in,
 2828                     inm->in6m_st[t].iss_rec);
 2829         }
 2830         printf("%s: --- end in6m %p ---\n", __func__, inm);
 2831 }
 2832 
 2833 #else /* !KTR */
 2834 
 2835 void
 2836 in6m_print(const struct in6_multi *inm)
 2837 {
 2838 
 2839 }
 2840 
 2841 #endif /* KTR */

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