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: releng/10.0/sys/netinet6/in6_mcast.c 254629 2013-08-22 00:51:37Z delphij $");
   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 static int      in6m_is_ifp_detached(const struct in6_multi *);
  135 static int      in6m_merge(struct in6_multi *, /*const*/ struct in6_mfilter *);
  136 static void     in6m_purge(struct in6_multi *);
  137 static void     in6m_reap(struct in6_multi *);
  138 static struct ip6_moptions *
  139                 in6p_findmoptions(struct inpcb *);
  140 static int      in6p_get_source_filters(struct inpcb *, struct sockopt *);
  141 static int      in6p_join_group(struct inpcb *, struct sockopt *);
  142 static int      in6p_leave_group(struct inpcb *, struct sockopt *);
  143 static struct ifnet *
  144                 in6p_lookup_mcast_ifp(const struct inpcb *,
  145                     const struct sockaddr_in6 *);
  146 static int      in6p_block_unblock_source(struct inpcb *, struct sockopt *);
  147 static int      in6p_set_multicast_if(struct inpcb *, struct sockopt *);
  148 static int      in6p_set_source_filters(struct inpcb *, struct sockopt *);
  149 static int      sysctl_ip6_mcast_filters(SYSCTL_HANDLER_ARGS);
  150 
  151 SYSCTL_DECL(_net_inet6_ip6);    /* XXX Not in any common header. */
  152 
  153 static SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, mcast, CTLFLAG_RW, 0,
  154     "IPv6 multicast");
  155 
  156 static u_long in6_mcast_maxgrpsrc = IPV6_MAX_GROUP_SRC_FILTER;
  157 SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxgrpsrc,
  158     CTLFLAG_RW | CTLFLAG_TUN, &in6_mcast_maxgrpsrc, 0,
  159     "Max source filters per group");
  160 TUNABLE_ULONG("net.inet6.ip6.mcast.maxgrpsrc", &in6_mcast_maxgrpsrc);
  161 
  162 static u_long in6_mcast_maxsocksrc = IPV6_MAX_SOCK_SRC_FILTER;
  163 SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxsocksrc,
  164     CTLFLAG_RW | CTLFLAG_TUN, &in6_mcast_maxsocksrc, 0,
  165     "Max source filters per socket");
  166 TUNABLE_ULONG("net.inet6.ip6.mcast.maxsocksrc", &in6_mcast_maxsocksrc);
  167 
  168 /* TODO Virtualize this switch. */
  169 int in6_mcast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
  170 SYSCTL_INT(_net_inet6_ip6_mcast, OID_AUTO, loop, CTLFLAG_RW | CTLFLAG_TUN,
  171     &in6_mcast_loop, 0, "Loopback multicast datagrams by default");
  172 TUNABLE_INT("net.inet6.ip6.mcast.loop", &in6_mcast_loop);
  173 
  174 static SYSCTL_NODE(_net_inet6_ip6_mcast, OID_AUTO, filters,
  175     CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_ip6_mcast_filters,
  176     "Per-interface stack-wide source filters");
  177 
  178 /*
  179  * Inline function which wraps assertions for a valid ifp.
  180  * The ifnet layer will set the ifma's ifp pointer to NULL if the ifp
  181  * is detached.
  182  */
  183 static int __inline
  184 in6m_is_ifp_detached(const struct in6_multi *inm)
  185 {
  186         struct ifnet *ifp;
  187 
  188         KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
  189         ifp = inm->in6m_ifma->ifma_ifp;
  190         if (ifp != NULL) {
  191                 /*
  192                  * Sanity check that network-layer notion of ifp is the
  193                  * same as that of link-layer.
  194                  */
  195                 KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
  196         }
  197 
  198         return (ifp == NULL);
  199 }
  200 
  201 /*
  202  * Initialize an in6_mfilter structure to a known state at t0, t1
  203  * with an empty source filter list.
  204  */
  205 static __inline void
  206 im6f_init(struct in6_mfilter *imf, const int st0, const int st1)
  207 {
  208         memset(imf, 0, sizeof(struct in6_mfilter));
  209         RB_INIT(&imf->im6f_sources);
  210         imf->im6f_st[0] = st0;
  211         imf->im6f_st[1] = st1;
  212 }
  213 
  214 /*
  215  * Resize the ip6_moptions vector to the next power-of-two minus 1.
  216  * May be called with locks held; do not sleep.
  217  */
  218 static int
  219 im6o_grow(struct ip6_moptions *imo)
  220 {
  221         struct in6_multi        **nmships;
  222         struct in6_multi        **omships;
  223         struct in6_mfilter       *nmfilters;
  224         struct in6_mfilter       *omfilters;
  225         size_t                    idx;
  226         size_t                    newmax;
  227         size_t                    oldmax;
  228 
  229         nmships = NULL;
  230         nmfilters = NULL;
  231         omships = imo->im6o_membership;
  232         omfilters = imo->im6o_mfilters;
  233         oldmax = imo->im6o_max_memberships;
  234         newmax = ((oldmax + 1) * 2) - 1;
  235 
  236         if (newmax <= IPV6_MAX_MEMBERSHIPS) {
  237                 nmships = (struct in6_multi **)realloc(omships,
  238                     sizeof(struct in6_multi *) * newmax, M_IP6MOPTS, M_NOWAIT);
  239                 nmfilters = (struct in6_mfilter *)realloc(omfilters,
  240                     sizeof(struct in6_mfilter) * newmax, M_IN6MFILTER,
  241                     M_NOWAIT);
  242                 if (nmships != NULL && nmfilters != NULL) {
  243                         /* Initialize newly allocated source filter heads. */
  244                         for (idx = oldmax; idx < newmax; idx++) {
  245                                 im6f_init(&nmfilters[idx], MCAST_UNDEFINED,
  246                                     MCAST_EXCLUDE);
  247                         }
  248                         imo->im6o_max_memberships = newmax;
  249                         imo->im6o_membership = nmships;
  250                         imo->im6o_mfilters = nmfilters;
  251                 }
  252         }
  253 
  254         if (nmships == NULL || nmfilters == NULL) {
  255                 if (nmships != NULL)
  256                         free(nmships, M_IP6MOPTS);
  257                 if (nmfilters != NULL)
  258                         free(nmfilters, M_IN6MFILTER);
  259                 return (ETOOMANYREFS);
  260         }
  261 
  262         return (0);
  263 }
  264 
  265 /*
  266  * Find an IPv6 multicast group entry for this ip6_moptions instance
  267  * which matches the specified group, and optionally an interface.
  268  * Return its index into the array, or -1 if not found.
  269  */
  270 static size_t
  271 im6o_match_group(const struct ip6_moptions *imo, const struct ifnet *ifp,
  272     const struct sockaddr *group)
  273 {
  274         const struct sockaddr_in6 *gsin6;
  275         struct in6_multi        **pinm;
  276         int               idx;
  277         int               nmships;
  278 
  279         gsin6 = (const struct sockaddr_in6 *)group;
  280 
  281         /* The im6o_membership array may be lazy allocated. */
  282         if (imo->im6o_membership == NULL || imo->im6o_num_memberships == 0)
  283                 return (-1);
  284 
  285         nmships = imo->im6o_num_memberships;
  286         pinm = &imo->im6o_membership[0];
  287         for (idx = 0; idx < nmships; idx++, pinm++) {
  288                 if (*pinm == NULL)
  289                         continue;
  290                 if ((ifp == NULL || ((*pinm)->in6m_ifp == ifp)) &&
  291                     IN6_ARE_ADDR_EQUAL(&(*pinm)->in6m_addr,
  292                     &gsin6->sin6_addr)) {
  293                         break;
  294                 }
  295         }
  296         if (idx >= nmships)
  297                 idx = -1;
  298 
  299         return (idx);
  300 }
  301 
  302 /*
  303  * Find an IPv6 multicast source entry for this imo which matches
  304  * the given group index for this socket, and source address.
  305  *
  306  * XXX TODO: The scope ID, if present in src, is stripped before
  307  * any comparison. We SHOULD enforce scope/zone checks where the source
  308  * filter entry has a link scope.
  309  *
  310  * NOTE: This does not check if the entry is in-mode, merely if
  311  * it exists, which may not be the desired behaviour.
  312  */
  313 static struct in6_msource *
  314 im6o_match_source(const struct ip6_moptions *imo, const size_t gidx,
  315     const struct sockaddr *src)
  316 {
  317         struct ip6_msource       find;
  318         struct in6_mfilter      *imf;
  319         struct ip6_msource      *ims;
  320         const sockunion_t       *psa;
  321 
  322         KASSERT(src->sa_family == AF_INET6, ("%s: !AF_INET6", __func__));
  323         KASSERT(gidx != -1 && gidx < imo->im6o_num_memberships,
  324             ("%s: invalid index %d\n", __func__, (int)gidx));
  325 
  326         /* The im6o_mfilters array may be lazy allocated. */
  327         if (imo->im6o_mfilters == NULL)
  328                 return (NULL);
  329         imf = &imo->im6o_mfilters[gidx];
  330 
  331         psa = (const sockunion_t *)src;
  332         find.im6s_addr = psa->sin6.sin6_addr;
  333         in6_clearscope(&find.im6s_addr);                /* XXX */
  334         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  335 
  336         return ((struct in6_msource *)ims);
  337 }
  338 
  339 /*
  340  * Perform filtering for multicast datagrams on a socket by group and source.
  341  *
  342  * Returns 0 if a datagram should be allowed through, or various error codes
  343  * if the socket was not a member of the group, or the source was muted, etc.
  344  */
  345 int
  346 im6o_mc_filter(const struct ip6_moptions *imo, const struct ifnet *ifp,
  347     const struct sockaddr *group, const struct sockaddr *src)
  348 {
  349         size_t gidx;
  350         struct in6_msource *ims;
  351         int mode;
  352 
  353         KASSERT(ifp != NULL, ("%s: null ifp", __func__));
  354 
  355         gidx = im6o_match_group(imo, ifp, group);
  356         if (gidx == -1)
  357                 return (MCAST_NOTGMEMBER);
  358 
  359         /*
  360          * Check if the source was included in an (S,G) join.
  361          * Allow reception on exclusive memberships by default,
  362          * reject reception on inclusive memberships by default.
  363          * Exclude source only if an in-mode exclude filter exists.
  364          * Include source only if an in-mode include filter exists.
  365          * NOTE: We are comparing group state here at MLD t1 (now)
  366          * with socket-layer t0 (since last downcall).
  367          */
  368         mode = imo->im6o_mfilters[gidx].im6f_st[1];
  369         ims = im6o_match_source(imo, gidx, src);
  370 
  371         if ((ims == NULL && mode == MCAST_INCLUDE) ||
  372             (ims != NULL && ims->im6sl_st[0] != mode))
  373                 return (MCAST_NOTSMEMBER);
  374 
  375         return (MCAST_PASS);
  376 }
  377 
  378 /*
  379  * Find and return a reference to an in6_multi record for (ifp, group),
  380  * and bump its reference count.
  381  * If one does not exist, try to allocate it, and update link-layer multicast
  382  * filters on ifp to listen for group.
  383  * Assumes the IN6_MULTI lock is held across the call.
  384  * Return 0 if successful, otherwise return an appropriate error code.
  385  */
  386 static int
  387 in6_mc_get(struct ifnet *ifp, const struct in6_addr *group,
  388     struct in6_multi **pinm)
  389 {
  390         struct sockaddr_in6      gsin6;
  391         struct ifmultiaddr      *ifma;
  392         struct in6_multi        *inm;
  393         int                      error;
  394 
  395         error = 0;
  396 
  397         /*
  398          * XXX: Accesses to ifma_protospec must be covered by IF_ADDR_LOCK;
  399          * if_addmulti() takes this mutex itself, so we must drop and
  400          * re-acquire around the call.
  401          */
  402         IN6_MULTI_LOCK_ASSERT();
  403         IF_ADDR_WLOCK(ifp);
  404 
  405         inm = in6m_lookup_locked(ifp, group);
  406         if (inm != NULL) {
  407                 /*
  408                  * If we already joined this group, just bump the
  409                  * refcount and return it.
  410                  */
  411                 KASSERT(inm->in6m_refcount >= 1,
  412                     ("%s: bad refcount %d", __func__, inm->in6m_refcount));
  413                 ++inm->in6m_refcount;
  414                 *pinm = inm;
  415                 goto out_locked;
  416         }
  417 
  418         memset(&gsin6, 0, sizeof(gsin6));
  419         gsin6.sin6_family = AF_INET6;
  420         gsin6.sin6_len = sizeof(struct sockaddr_in6);
  421         gsin6.sin6_addr = *group;
  422 
  423         /*
  424          * Check if a link-layer group is already associated
  425          * with this network-layer group on the given ifnet.
  426          */
  427         IF_ADDR_WUNLOCK(ifp);
  428         error = if_addmulti(ifp, (struct sockaddr *)&gsin6, &ifma);
  429         if (error != 0)
  430                 return (error);
  431         IF_ADDR_WLOCK(ifp);
  432 
  433         /*
  434          * If something other than netinet6 is occupying the link-layer
  435          * group, print a meaningful error message and back out of
  436          * the allocation.
  437          * Otherwise, bump the refcount on the existing network-layer
  438          * group association and return it.
  439          */
  440         if (ifma->ifma_protospec != NULL) {
  441                 inm = (struct in6_multi *)ifma->ifma_protospec;
  442 #ifdef INVARIANTS
  443                 KASSERT(ifma->ifma_addr != NULL, ("%s: no ifma_addr",
  444                     __func__));
  445                 KASSERT(ifma->ifma_addr->sa_family == AF_INET6,
  446                     ("%s: ifma not AF_INET6", __func__));
  447                 KASSERT(inm != NULL, ("%s: no ifma_protospec", __func__));
  448                 if (inm->in6m_ifma != ifma || inm->in6m_ifp != ifp ||
  449                     !IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, group))
  450                         panic("%s: ifma %p is inconsistent with %p (%p)",
  451                             __func__, ifma, inm, group);
  452 #endif
  453                 ++inm->in6m_refcount;
  454                 *pinm = inm;
  455                 goto out_locked;
  456         }
  457 
  458         IF_ADDR_WLOCK_ASSERT(ifp);
  459 
  460         /*
  461          * A new in6_multi record is needed; allocate and initialize it.
  462          * We DO NOT perform an MLD join as the in6_ layer may need to
  463          * push an initial source list down to MLD to support SSM.
  464          *
  465          * The initial source filter state is INCLUDE, {} as per the RFC.
  466          * Pending state-changes per group are subject to a bounds check.
  467          */
  468         inm = malloc(sizeof(*inm), M_IP6MADDR, M_NOWAIT | M_ZERO);
  469         if (inm == NULL) {
  470                 if_delmulti_ifma(ifma);
  471                 error = ENOMEM;
  472                 goto out_locked;
  473         }
  474         inm->in6m_addr = *group;
  475         inm->in6m_ifp = ifp;
  476         inm->in6m_mli = MLD_IFINFO(ifp);
  477         inm->in6m_ifma = ifma;
  478         inm->in6m_refcount = 1;
  479         inm->in6m_state = MLD_NOT_MEMBER;
  480         IFQ_SET_MAXLEN(&inm->in6m_scq, MLD_MAX_STATE_CHANGES);
  481 
  482         inm->in6m_st[0].iss_fmode = MCAST_UNDEFINED;
  483         inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
  484         RB_INIT(&inm->in6m_srcs);
  485 
  486         ifma->ifma_protospec = inm;
  487         *pinm = inm;
  488 
  489 out_locked:
  490         IF_ADDR_WUNLOCK(ifp);
  491         return (error);
  492 }
  493 
  494 /*
  495  * Drop a reference to an in6_multi record.
  496  *
  497  * If the refcount drops to 0, free the in6_multi record and
  498  * delete the underlying link-layer membership.
  499  */
  500 void
  501 in6m_release_locked(struct in6_multi *inm)
  502 {
  503         struct ifmultiaddr *ifma;
  504 
  505         IN6_MULTI_LOCK_ASSERT();
  506 
  507         CTR2(KTR_MLD, "%s: refcount is %d", __func__, inm->in6m_refcount);
  508 
  509         if (--inm->in6m_refcount > 0) {
  510                 CTR2(KTR_MLD, "%s: refcount is now %d", __func__,
  511                     inm->in6m_refcount);
  512                 return;
  513         }
  514 
  515         CTR2(KTR_MLD, "%s: freeing inm %p", __func__, inm);
  516 
  517         ifma = inm->in6m_ifma;
  518 
  519         /* XXX this access is not covered by IF_ADDR_LOCK */
  520         CTR2(KTR_MLD, "%s: purging ifma %p", __func__, ifma);
  521         KASSERT(ifma->ifma_protospec == inm,
  522             ("%s: ifma_protospec != inm", __func__));
  523         ifma->ifma_protospec = NULL;
  524 
  525         in6m_purge(inm);
  526 
  527         free(inm, M_IP6MADDR);
  528 
  529         if_delmulti_ifma(ifma);
  530 }
  531 
  532 /*
  533  * Clear recorded source entries for a group.
  534  * Used by the MLD code. Caller must hold the IN6_MULTI lock.
  535  * FIXME: Should reap.
  536  */
  537 void
  538 in6m_clear_recorded(struct in6_multi *inm)
  539 {
  540         struct ip6_msource      *ims;
  541 
  542         IN6_MULTI_LOCK_ASSERT();
  543 
  544         RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
  545                 if (ims->im6s_stp) {
  546                         ims->im6s_stp = 0;
  547                         --inm->in6m_st[1].iss_rec;
  548                 }
  549         }
  550         KASSERT(inm->in6m_st[1].iss_rec == 0,
  551             ("%s: iss_rec %d not 0", __func__, inm->in6m_st[1].iss_rec));
  552 }
  553 
  554 /*
  555  * Record a source as pending for a Source-Group MLDv2 query.
  556  * This lives here as it modifies the shared tree.
  557  *
  558  * inm is the group descriptor.
  559  * naddr is the address of the source to record in network-byte order.
  560  *
  561  * If the net.inet6.mld.sgalloc sysctl is non-zero, we will
  562  * lazy-allocate a source node in response to an SG query.
  563  * Otherwise, no allocation is performed. This saves some memory
  564  * with the trade-off that the source will not be reported to the
  565  * router if joined in the window between the query response and
  566  * the group actually being joined on the local host.
  567  *
  568  * VIMAGE: XXX: Currently the mld_sgalloc feature has been removed.
  569  * This turns off the allocation of a recorded source entry if
  570  * the group has not been joined.
  571  *
  572  * Return 0 if the source didn't exist or was already marked as recorded.
  573  * Return 1 if the source was marked as recorded by this function.
  574  * Return <0 if any error occured (negated errno code).
  575  */
  576 int
  577 in6m_record_source(struct in6_multi *inm, const struct in6_addr *addr)
  578 {
  579         struct ip6_msource       find;
  580         struct ip6_msource      *ims, *nims;
  581 
  582         IN6_MULTI_LOCK_ASSERT();
  583 
  584         find.im6s_addr = *addr;
  585         ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
  586         if (ims && ims->im6s_stp)
  587                 return (0);
  588         if (ims == NULL) {
  589                 if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
  590                         return (-ENOSPC);
  591                 nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
  592                     M_NOWAIT | M_ZERO);
  593                 if (nims == NULL)
  594                         return (-ENOMEM);
  595                 nims->im6s_addr = find.im6s_addr;
  596                 RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
  597                 ++inm->in6m_nsrc;
  598                 ims = nims;
  599         }
  600 
  601         /*
  602          * Mark the source as recorded and update the recorded
  603          * source count.
  604          */
  605         ++ims->im6s_stp;
  606         ++inm->in6m_st[1].iss_rec;
  607 
  608         return (1);
  609 }
  610 
  611 /*
  612  * Return a pointer to an in6_msource owned by an in6_mfilter,
  613  * given its source address.
  614  * Lazy-allocate if needed. If this is a new entry its filter state is
  615  * undefined at t0.
  616  *
  617  * imf is the filter set being modified.
  618  * addr is the source address.
  619  *
  620  * SMPng: May be called with locks held; malloc must not block.
  621  */
  622 static int
  623 im6f_get_source(struct in6_mfilter *imf, const struct sockaddr_in6 *psin,
  624     struct in6_msource **plims)
  625 {
  626         struct ip6_msource       find;
  627         struct ip6_msource      *ims, *nims;
  628         struct in6_msource      *lims;
  629         int                      error;
  630 
  631         error = 0;
  632         ims = NULL;
  633         lims = NULL;
  634 
  635         find.im6s_addr = psin->sin6_addr;
  636         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  637         lims = (struct in6_msource *)ims;
  638         if (lims == NULL) {
  639                 if (imf->im6f_nsrc == in6_mcast_maxsocksrc)
  640                         return (ENOSPC);
  641                 nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
  642                     M_NOWAIT | M_ZERO);
  643                 if (nims == NULL)
  644                         return (ENOMEM);
  645                 lims = (struct in6_msource *)nims;
  646                 lims->im6s_addr = find.im6s_addr;
  647                 lims->im6sl_st[0] = MCAST_UNDEFINED;
  648                 RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
  649                 ++imf->im6f_nsrc;
  650         }
  651 
  652         *plims = lims;
  653 
  654         return (error);
  655 }
  656 
  657 /*
  658  * Graft a source entry into an existing socket-layer filter set,
  659  * maintaining any required invariants and checking allocations.
  660  *
  661  * The source is marked as being in the new filter mode at t1.
  662  *
  663  * Return the pointer to the new node, otherwise return NULL.
  664  */
  665 static struct in6_msource *
  666 im6f_graft(struct in6_mfilter *imf, const uint8_t st1,
  667     const struct sockaddr_in6 *psin)
  668 {
  669         struct ip6_msource      *nims;
  670         struct in6_msource      *lims;
  671 
  672         nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
  673             M_NOWAIT | M_ZERO);
  674         if (nims == NULL)
  675                 return (NULL);
  676         lims = (struct in6_msource *)nims;
  677         lims->im6s_addr = psin->sin6_addr;
  678         lims->im6sl_st[0] = MCAST_UNDEFINED;
  679         lims->im6sl_st[1] = st1;
  680         RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
  681         ++imf->im6f_nsrc;
  682 
  683         return (lims);
  684 }
  685 
  686 /*
  687  * Prune a source entry from an existing socket-layer filter set,
  688  * maintaining any required invariants and checking allocations.
  689  *
  690  * The source is marked as being left at t1, it is not freed.
  691  *
  692  * Return 0 if no error occurred, otherwise return an errno value.
  693  */
  694 static int
  695 im6f_prune(struct in6_mfilter *imf, const struct sockaddr_in6 *psin)
  696 {
  697         struct ip6_msource       find;
  698         struct ip6_msource      *ims;
  699         struct in6_msource      *lims;
  700 
  701         find.im6s_addr = psin->sin6_addr;
  702         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  703         if (ims == NULL)
  704                 return (ENOENT);
  705         lims = (struct in6_msource *)ims;
  706         lims->im6sl_st[1] = MCAST_UNDEFINED;
  707         return (0);
  708 }
  709 
  710 /*
  711  * Revert socket-layer filter set deltas at t1 to t0 state.
  712  */
  713 static void
  714 im6f_rollback(struct in6_mfilter *imf)
  715 {
  716         struct ip6_msource      *ims, *tims;
  717         struct in6_msource      *lims;
  718 
  719         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  720                 lims = (struct in6_msource *)ims;
  721                 if (lims->im6sl_st[0] == lims->im6sl_st[1]) {
  722                         /* no change at t1 */
  723                         continue;
  724                 } else if (lims->im6sl_st[0] != MCAST_UNDEFINED) {
  725                         /* revert change to existing source at t1 */
  726                         lims->im6sl_st[1] = lims->im6sl_st[0];
  727                 } else {
  728                         /* revert source added t1 */
  729                         CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
  730                         RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  731                         free(ims, M_IN6MFILTER);
  732                         imf->im6f_nsrc--;
  733                 }
  734         }
  735         imf->im6f_st[1] = imf->im6f_st[0];
  736 }
  737 
  738 /*
  739  * Mark socket-layer filter set as INCLUDE {} at t1.
  740  */
  741 static void
  742 im6f_leave(struct in6_mfilter *imf)
  743 {
  744         struct ip6_msource      *ims;
  745         struct in6_msource      *lims;
  746 
  747         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  748                 lims = (struct in6_msource *)ims;
  749                 lims->im6sl_st[1] = MCAST_UNDEFINED;
  750         }
  751         imf->im6f_st[1] = MCAST_INCLUDE;
  752 }
  753 
  754 /*
  755  * Mark socket-layer filter set deltas as committed.
  756  */
  757 static void
  758 im6f_commit(struct in6_mfilter *imf)
  759 {
  760         struct ip6_msource      *ims;
  761         struct in6_msource      *lims;
  762 
  763         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  764                 lims = (struct in6_msource *)ims;
  765                 lims->im6sl_st[0] = lims->im6sl_st[1];
  766         }
  767         imf->im6f_st[0] = imf->im6f_st[1];
  768 }
  769 
  770 /*
  771  * Reap unreferenced sources from socket-layer filter set.
  772  */
  773 static void
  774 im6f_reap(struct in6_mfilter *imf)
  775 {
  776         struct ip6_msource      *ims, *tims;
  777         struct in6_msource      *lims;
  778 
  779         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  780                 lims = (struct in6_msource *)ims;
  781                 if ((lims->im6sl_st[0] == MCAST_UNDEFINED) &&
  782                     (lims->im6sl_st[1] == MCAST_UNDEFINED)) {
  783                         CTR2(KTR_MLD, "%s: free lims %p", __func__, ims);
  784                         RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  785                         free(ims, M_IN6MFILTER);
  786                         imf->im6f_nsrc--;
  787                 }
  788         }
  789 }
  790 
  791 /*
  792  * Purge socket-layer filter set.
  793  */
  794 static void
  795 im6f_purge(struct in6_mfilter *imf)
  796 {
  797         struct ip6_msource      *ims, *tims;
  798 
  799         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  800                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
  801                 RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  802                 free(ims, M_IN6MFILTER);
  803                 imf->im6f_nsrc--;
  804         }
  805         imf->im6f_st[0] = imf->im6f_st[1] = MCAST_UNDEFINED;
  806         KASSERT(RB_EMPTY(&imf->im6f_sources),
  807             ("%s: im6f_sources not empty", __func__));
  808 }
  809 
  810 /*
  811  * Look up a source filter entry for a multicast group.
  812  *
  813  * inm is the group descriptor to work with.
  814  * addr is the IPv6 address to look up.
  815  * noalloc may be non-zero to suppress allocation of sources.
  816  * *pims will be set to the address of the retrieved or allocated source.
  817  *
  818  * SMPng: NOTE: may be called with locks held.
  819  * Return 0 if successful, otherwise return a non-zero error code.
  820  */
  821 static int
  822 in6m_get_source(struct in6_multi *inm, const struct in6_addr *addr,
  823     const int noalloc, struct ip6_msource **pims)
  824 {
  825         struct ip6_msource       find;
  826         struct ip6_msource      *ims, *nims;
  827 #ifdef KTR
  828         char                     ip6tbuf[INET6_ADDRSTRLEN];
  829 #endif
  830 
  831         find.im6s_addr = *addr;
  832         ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
  833         if (ims == NULL && !noalloc) {
  834                 if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
  835                         return (ENOSPC);
  836                 nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
  837                     M_NOWAIT | M_ZERO);
  838                 if (nims == NULL)
  839                         return (ENOMEM);
  840                 nims->im6s_addr = *addr;
  841                 RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
  842                 ++inm->in6m_nsrc;
  843                 ims = nims;
  844                 CTR3(KTR_MLD, "%s: allocated %s as %p", __func__,
  845                     ip6_sprintf(ip6tbuf, addr), ims);
  846         }
  847 
  848         *pims = ims;
  849         return (0);
  850 }
  851 
  852 /*
  853  * Merge socket-layer source into MLD-layer source.
  854  * If rollback is non-zero, perform the inverse of the merge.
  855  */
  856 static void
  857 im6s_merge(struct ip6_msource *ims, const struct in6_msource *lims,
  858     const int rollback)
  859 {
  860         int n = rollback ? -1 : 1;
  861 #ifdef KTR
  862         char ip6tbuf[INET6_ADDRSTRLEN];
  863 
  864         ip6_sprintf(ip6tbuf, &lims->im6s_addr);
  865 #endif
  866 
  867         if (lims->im6sl_st[0] == MCAST_EXCLUDE) {
  868                 CTR3(KTR_MLD, "%s: t1 ex -= %d on %s", __func__, n, ip6tbuf);
  869                 ims->im6s_st[1].ex -= n;
  870         } else if (lims->im6sl_st[0] == MCAST_INCLUDE) {
  871                 CTR3(KTR_MLD, "%s: t1 in -= %d on %s", __func__, n, ip6tbuf);
  872                 ims->im6s_st[1].in -= n;
  873         }
  874 
  875         if (lims->im6sl_st[1] == MCAST_EXCLUDE) {
  876                 CTR3(KTR_MLD, "%s: t1 ex += %d on %s", __func__, n, ip6tbuf);
  877                 ims->im6s_st[1].ex += n;
  878         } else if (lims->im6sl_st[1] == MCAST_INCLUDE) {
  879                 CTR3(KTR_MLD, "%s: t1 in += %d on %s", __func__, n, ip6tbuf);
  880                 ims->im6s_st[1].in += n;
  881         }
  882 }
  883 
  884 /*
  885  * Atomically update the global in6_multi state, when a membership's
  886  * filter list is being updated in any way.
  887  *
  888  * imf is the per-inpcb-membership group filter pointer.
  889  * A fake imf may be passed for in-kernel consumers.
  890  *
  891  * XXX This is a candidate for a set-symmetric-difference style loop
  892  * which would eliminate the repeated lookup from root of ims nodes,
  893  * as they share the same key space.
  894  *
  895  * If any error occurred this function will back out of refcounts
  896  * and return a non-zero value.
  897  */
  898 static int
  899 in6m_merge(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
  900 {
  901         struct ip6_msource      *ims, *nims;
  902         struct in6_msource      *lims;
  903         int                      schanged, error;
  904         int                      nsrc0, nsrc1;
  905 
  906         schanged = 0;
  907         error = 0;
  908         nsrc1 = nsrc0 = 0;
  909 
  910         /*
  911          * Update the source filters first, as this may fail.
  912          * Maintain count of in-mode filters at t0, t1. These are
  913          * used to work out if we transition into ASM mode or not.
  914          * Maintain a count of source filters whose state was
  915          * actually modified by this operation.
  916          */
  917         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  918                 lims = (struct in6_msource *)ims;
  919                 if (lims->im6sl_st[0] == imf->im6f_st[0]) nsrc0++;
  920                 if (lims->im6sl_st[1] == imf->im6f_st[1]) nsrc1++;
  921                 if (lims->im6sl_st[0] == lims->im6sl_st[1]) continue;
  922                 error = in6m_get_source(inm, &lims->im6s_addr, 0, &nims);
  923                 ++schanged;
  924                 if (error)
  925                         break;
  926                 im6s_merge(nims, lims, 0);
  927         }
  928         if (error) {
  929                 struct ip6_msource *bims;
  930 
  931                 RB_FOREACH_REVERSE_FROM(ims, ip6_msource_tree, nims) {
  932                         lims = (struct in6_msource *)ims;
  933                         if (lims->im6sl_st[0] == lims->im6sl_st[1])
  934                                 continue;
  935                         (void)in6m_get_source(inm, &lims->im6s_addr, 1, &bims);
  936                         if (bims == NULL)
  937                                 continue;
  938                         im6s_merge(bims, lims, 1);
  939                 }
  940                 goto out_reap;
  941         }
  942 
  943         CTR3(KTR_MLD, "%s: imf filters in-mode: %d at t0, %d at t1",
  944             __func__, nsrc0, nsrc1);
  945 
  946         /* Handle transition between INCLUDE {n} and INCLUDE {} on socket. */
  947         if (imf->im6f_st[0] == imf->im6f_st[1] &&
  948             imf->im6f_st[1] == MCAST_INCLUDE) {
  949                 if (nsrc1 == 0) {
  950                         CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
  951                         --inm->in6m_st[1].iss_in;
  952                 }
  953         }
  954 
  955         /* Handle filter mode transition on socket. */
  956         if (imf->im6f_st[0] != imf->im6f_st[1]) {
  957                 CTR3(KTR_MLD, "%s: imf transition %d to %d",
  958                     __func__, imf->im6f_st[0], imf->im6f_st[1]);
  959 
  960                 if (imf->im6f_st[0] == MCAST_EXCLUDE) {
  961                         CTR1(KTR_MLD, "%s: --ex on inm at t1", __func__);
  962                         --inm->in6m_st[1].iss_ex;
  963                 } else if (imf->im6f_st[0] == MCAST_INCLUDE) {
  964                         CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
  965                         --inm->in6m_st[1].iss_in;
  966                 }
  967 
  968                 if (imf->im6f_st[1] == MCAST_EXCLUDE) {
  969                         CTR1(KTR_MLD, "%s: ex++ on inm at t1", __func__);
  970                         inm->in6m_st[1].iss_ex++;
  971                 } else if (imf->im6f_st[1] == MCAST_INCLUDE && nsrc1 > 0) {
  972                         CTR1(KTR_MLD, "%s: in++ on inm at t1", __func__);
  973                         inm->in6m_st[1].iss_in++;
  974                 }
  975         }
  976 
  977         /*
  978          * Track inm filter state in terms of listener counts.
  979          * If there are any exclusive listeners, stack-wide
  980          * membership is exclusive.
  981          * Otherwise, if only inclusive listeners, stack-wide is inclusive.
  982          * If no listeners remain, state is undefined at t1,
  983          * and the MLD lifecycle for this group should finish.
  984          */
  985         if (inm->in6m_st[1].iss_ex > 0) {
  986                 CTR1(KTR_MLD, "%s: transition to EX", __func__);
  987                 inm->in6m_st[1].iss_fmode = MCAST_EXCLUDE;
  988         } else if (inm->in6m_st[1].iss_in > 0) {
  989                 CTR1(KTR_MLD, "%s: transition to IN", __func__);
  990                 inm->in6m_st[1].iss_fmode = MCAST_INCLUDE;
  991         } else {
  992                 CTR1(KTR_MLD, "%s: transition to UNDEF", __func__);
  993                 inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
  994         }
  995 
  996         /* Decrement ASM listener count on transition out of ASM mode. */
  997         if (imf->im6f_st[0] == MCAST_EXCLUDE && nsrc0 == 0) {
  998                 if ((imf->im6f_st[1] != MCAST_EXCLUDE) ||
  999                     (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 > 0))
 1000                         CTR1(KTR_MLD, "%s: --asm on inm at t1", __func__);
 1001                         --inm->in6m_st[1].iss_asm;
 1002         }
 1003 
 1004         /* Increment ASM listener count on transition to ASM mode. */
 1005         if (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 == 0) {
 1006                 CTR1(KTR_MLD, "%s: asm++ on inm at t1", __func__);
 1007                 inm->in6m_st[1].iss_asm++;
 1008         }
 1009 
 1010         CTR3(KTR_MLD, "%s: merged imf %p to inm %p", __func__, imf, inm);
 1011         in6m_print(inm);
 1012 
 1013 out_reap:
 1014         if (schanged > 0) {
 1015                 CTR1(KTR_MLD, "%s: sources changed; reaping", __func__);
 1016                 in6m_reap(inm);
 1017         }
 1018         return (error);
 1019 }
 1020 
 1021 /*
 1022  * Mark an in6_multi's filter set deltas as committed.
 1023  * Called by MLD after a state change has been enqueued.
 1024  */
 1025 void
 1026 in6m_commit(struct in6_multi *inm)
 1027 {
 1028         struct ip6_msource      *ims;
 1029 
 1030         CTR2(KTR_MLD, "%s: commit inm %p", __func__, inm);
 1031         CTR1(KTR_MLD, "%s: pre commit:", __func__);
 1032         in6m_print(inm);
 1033 
 1034         RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
 1035                 ims->im6s_st[0] = ims->im6s_st[1];
 1036         }
 1037         inm->in6m_st[0] = inm->in6m_st[1];
 1038 }
 1039 
 1040 /*
 1041  * Reap unreferenced nodes from an in6_multi's filter set.
 1042  */
 1043 static void
 1044 in6m_reap(struct in6_multi *inm)
 1045 {
 1046         struct ip6_msource      *ims, *tims;
 1047 
 1048         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1049                 if (ims->im6s_st[0].ex > 0 || ims->im6s_st[0].in > 0 ||
 1050                     ims->im6s_st[1].ex > 0 || ims->im6s_st[1].in > 0 ||
 1051                     ims->im6s_stp != 0)
 1052                         continue;
 1053                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1054                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1055                 free(ims, M_IP6MSOURCE);
 1056                 inm->in6m_nsrc--;
 1057         }
 1058 }
 1059 
 1060 /*
 1061  * Purge all source nodes from an in6_multi's filter set.
 1062  */
 1063 static void
 1064 in6m_purge(struct in6_multi *inm)
 1065 {
 1066         struct ip6_msource      *ims, *tims;
 1067 
 1068         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1069                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1070                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1071                 free(ims, M_IP6MSOURCE);
 1072                 inm->in6m_nsrc--;
 1073         }
 1074 }
 1075 
 1076 /*
 1077  * Join a multicast address w/o sources.
 1078  * KAME compatibility entry point.
 1079  *
 1080  * SMPng: Assume no mc locks held by caller.
 1081  */
 1082 struct in6_multi_mship *
 1083 in6_joingroup(struct ifnet *ifp, struct in6_addr *mcaddr,
 1084     int *errorp, int delay)
 1085 {
 1086         struct in6_multi_mship *imm;
 1087         int error;
 1088 
 1089         imm = malloc(sizeof(*imm), M_IP6MADDR, M_NOWAIT);
 1090         if (imm == NULL) {
 1091                 *errorp = ENOBUFS;
 1092                 return (NULL);
 1093         }
 1094 
 1095         delay = (delay * PR_FASTHZ) / hz;
 1096 
 1097         error = in6_mc_join(ifp, mcaddr, NULL, &imm->i6mm_maddr, delay);
 1098         if (error) {
 1099                 *errorp = error;
 1100                 free(imm, M_IP6MADDR);
 1101                 return (NULL);
 1102         }
 1103 
 1104         return (imm);
 1105 }
 1106 
 1107 /*
 1108  * Leave a multicast address w/o sources.
 1109  * KAME compatibility entry point.
 1110  *
 1111  * SMPng: Assume no mc locks held by caller.
 1112  */
 1113 int
 1114 in6_leavegroup(struct in6_multi_mship *imm)
 1115 {
 1116 
 1117         if (imm->i6mm_maddr != NULL)
 1118                 in6_mc_leave(imm->i6mm_maddr, NULL);
 1119         free(imm,  M_IP6MADDR);
 1120         return 0;
 1121 }
 1122 
 1123 /*
 1124  * Join a multicast group; unlocked entry point.
 1125  *
 1126  * SMPng: XXX: in6_mc_join() is called from in6_control() when upper
 1127  * locks are not held. Fortunately, ifp is unlikely to have been detached
 1128  * at this point, so we assume it's OK to recurse.
 1129  */
 1130 int
 1131 in6_mc_join(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1132     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1133     const int delay)
 1134 {
 1135         int error;
 1136 
 1137         IN6_MULTI_LOCK();
 1138         error = in6_mc_join_locked(ifp, mcaddr, imf, pinm, delay);
 1139         IN6_MULTI_UNLOCK();
 1140 
 1141         return (error);
 1142 }
 1143 
 1144 /*
 1145  * Join a multicast group; real entry point.
 1146  *
 1147  * Only preserves atomicity at inm level.
 1148  * NOTE: imf argument cannot be const due to sys/tree.h limitations.
 1149  *
 1150  * If the MLD downcall fails, the group is not joined, and an error
 1151  * code is returned.
 1152  */
 1153 int
 1154 in6_mc_join_locked(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1155     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1156     const int delay)
 1157 {
 1158         struct in6_mfilter       timf;
 1159         struct in6_multi        *inm;
 1160         int                      error;
 1161 #ifdef KTR
 1162         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1163 #endif
 1164 
 1165 #ifdef INVARIANTS
 1166         /*
 1167          * Sanity: Check scope zone ID was set for ifp, if and
 1168          * only if group is scoped to an interface.
 1169          */
 1170         KASSERT(IN6_IS_ADDR_MULTICAST(mcaddr),
 1171             ("%s: not a multicast address", __func__));
 1172         if (IN6_IS_ADDR_MC_LINKLOCAL(mcaddr) ||
 1173             IN6_IS_ADDR_MC_INTFACELOCAL(mcaddr)) {
 1174                 KASSERT(mcaddr->s6_addr16[1] != 0,
 1175                     ("%s: scope zone ID not set", __func__));
 1176         }
 1177 #endif
 1178 
 1179         IN6_MULTI_LOCK_ASSERT();
 1180 
 1181         CTR4(KTR_MLD, "%s: join %s on %p(%s))", __func__,
 1182             ip6_sprintf(ip6tbuf, mcaddr), ifp, ifp->if_xname);
 1183 
 1184         error = 0;
 1185         inm = NULL;
 1186 
 1187         /*
 1188          * If no imf was specified (i.e. kernel consumer),
 1189          * fake one up and assume it is an ASM join.
 1190          */
 1191         if (imf == NULL) {
 1192                 im6f_init(&timf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 1193                 imf = &timf;
 1194         }
 1195 
 1196         error = in6_mc_get(ifp, mcaddr, &inm);
 1197         if (error) {
 1198                 CTR1(KTR_MLD, "%s: in6_mc_get() failure", __func__);
 1199                 return (error);
 1200         }
 1201 
 1202         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1203         error = in6m_merge(inm, imf);
 1204         if (error) {
 1205                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1206                 goto out_in6m_release;
 1207         }
 1208 
 1209         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1210         error = mld_change_state(inm, delay);
 1211         if (error) {
 1212                 CTR1(KTR_MLD, "%s: failed to update source", __func__);
 1213                 goto out_in6m_release;
 1214         }
 1215 
 1216 out_in6m_release:
 1217         if (error) {
 1218                 CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1219                 in6m_release_locked(inm);
 1220         } else {
 1221                 *pinm = inm;
 1222         }
 1223 
 1224         return (error);
 1225 }
 1226 
 1227 /*
 1228  * Leave a multicast group; unlocked entry point.
 1229  */
 1230 int
 1231 in6_mc_leave(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1232 {
 1233         struct ifnet *ifp;
 1234         int error;
 1235 
 1236         ifp = inm->in6m_ifp;
 1237 
 1238         IN6_MULTI_LOCK();
 1239         error = in6_mc_leave_locked(inm, imf);
 1240         IN6_MULTI_UNLOCK();
 1241 
 1242         return (error);
 1243 }
 1244 
 1245 /*
 1246  * Leave a multicast group; real entry point.
 1247  * All source filters will be expunged.
 1248  *
 1249  * Only preserves atomicity at inm level.
 1250  *
 1251  * Holding the write lock for the INP which contains imf
 1252  * is highly advisable. We can't assert for it as imf does not
 1253  * contain a back-pointer to the owning inp.
 1254  *
 1255  * Note: This is not the same as in6m_release(*) as this function also
 1256  * makes a state change downcall into MLD.
 1257  */
 1258 int
 1259 in6_mc_leave_locked(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1260 {
 1261         struct in6_mfilter       timf;
 1262         int                      error;
 1263 #ifdef KTR
 1264         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1265 #endif
 1266 
 1267         error = 0;
 1268 
 1269         IN6_MULTI_LOCK_ASSERT();
 1270 
 1271         CTR5(KTR_MLD, "%s: leave inm %p, %s/%s, imf %p", __func__,
 1272             inm, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 1273             (in6m_is_ifp_detached(inm) ? "null" : inm->in6m_ifp->if_xname),
 1274             imf);
 1275 
 1276         /*
 1277          * If no imf was specified (i.e. kernel consumer),
 1278          * fake one up and assume it is an ASM join.
 1279          */
 1280         if (imf == NULL) {
 1281                 im6f_init(&timf, MCAST_EXCLUDE, MCAST_UNDEFINED);
 1282                 imf = &timf;
 1283         }
 1284 
 1285         /*
 1286          * Begin state merge transaction at MLD layer.
 1287          *
 1288          * As this particular invocation should not cause any memory
 1289          * to be allocated, and there is no opportunity to roll back
 1290          * the transaction, it MUST NOT fail.
 1291          */
 1292         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1293         error = in6m_merge(inm, imf);
 1294         KASSERT(error == 0, ("%s: failed to merge inm state", __func__));
 1295 
 1296         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1297         error = mld_change_state(inm, 0);
 1298         if (error)
 1299                 CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1300 
 1301         CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1302         in6m_release_locked(inm);
 1303 
 1304         return (error);
 1305 }
 1306 
 1307 /*
 1308  * Block or unblock an ASM multicast source on an inpcb.
 1309  * This implements the delta-based API described in RFC 3678.
 1310  *
 1311  * The delta-based API applies only to exclusive-mode memberships.
 1312  * An MLD downcall will be performed.
 1313  *
 1314  * SMPng: NOTE: Must take Giant as a join may create a new ifma.
 1315  *
 1316  * Return 0 if successful, otherwise return an appropriate error code.
 1317  */
 1318 static int
 1319 in6p_block_unblock_source(struct inpcb *inp, struct sockopt *sopt)
 1320 {
 1321         struct group_source_req          gsr;
 1322         sockunion_t                     *gsa, *ssa;
 1323         struct ifnet                    *ifp;
 1324         struct in6_mfilter              *imf;
 1325         struct ip6_moptions             *imo;
 1326         struct in6_msource              *ims;
 1327         struct in6_multi                        *inm;
 1328         size_t                           idx;
 1329         uint16_t                         fmode;
 1330         int                              error, doblock;
 1331 #ifdef KTR
 1332         char                             ip6tbuf[INET6_ADDRSTRLEN];
 1333 #endif
 1334 
 1335         ifp = NULL;
 1336         error = 0;
 1337         doblock = 0;
 1338 
 1339         memset(&gsr, 0, sizeof(struct group_source_req));
 1340         gsa = (sockunion_t *)&gsr.gsr_group;
 1341         ssa = (sockunion_t *)&gsr.gsr_source;
 1342 
 1343         switch (sopt->sopt_name) {
 1344         case MCAST_BLOCK_SOURCE:
 1345         case MCAST_UNBLOCK_SOURCE:
 1346                 error = sooptcopyin(sopt, &gsr,
 1347                     sizeof(struct group_source_req),
 1348                     sizeof(struct group_source_req));
 1349                 if (error)
 1350                         return (error);
 1351 
 1352                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1353                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1354                         return (EINVAL);
 1355 
 1356                 if (ssa->sin6.sin6_family != AF_INET6 ||
 1357                     ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1358                         return (EINVAL);
 1359 
 1360                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1361                         return (EADDRNOTAVAIL);
 1362 
 1363                 ifp = ifnet_byindex(gsr.gsr_interface);
 1364 
 1365                 if (sopt->sopt_name == MCAST_BLOCK_SOURCE)
 1366                         doblock = 1;
 1367                 break;
 1368 
 1369         default:
 1370                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1371                     __func__, sopt->sopt_name);
 1372                 return (EOPNOTSUPP);
 1373                 break;
 1374         }
 1375 
 1376         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1377                 return (EINVAL);
 1378 
 1379         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1380 
 1381         /*
 1382          * Check if we are actually a member of this group.
 1383          */
 1384         imo = in6p_findmoptions(inp);
 1385         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1386         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1387                 error = EADDRNOTAVAIL;
 1388                 goto out_in6p_locked;
 1389         }
 1390 
 1391         KASSERT(imo->im6o_mfilters != NULL,
 1392             ("%s: im6o_mfilters not allocated", __func__));
 1393         imf = &imo->im6o_mfilters[idx];
 1394         inm = imo->im6o_membership[idx];
 1395 
 1396         /*
 1397          * Attempting to use the delta-based API on an
 1398          * non exclusive-mode membership is an error.
 1399          */
 1400         fmode = imf->im6f_st[0];
 1401         if (fmode != MCAST_EXCLUDE) {
 1402                 error = EINVAL;
 1403                 goto out_in6p_locked;
 1404         }
 1405 
 1406         /*
 1407          * Deal with error cases up-front:
 1408          *  Asked to block, but already blocked; or
 1409          *  Asked to unblock, but nothing to unblock.
 1410          * If adding a new block entry, allocate it.
 1411          */
 1412         ims = im6o_match_source(imo, idx, &ssa->sa);
 1413         if ((ims != NULL && doblock) || (ims == NULL && !doblock)) {
 1414                 CTR3(KTR_MLD, "%s: source %s %spresent", __func__,
 1415                     ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 1416                     doblock ? "" : "not ");
 1417                 error = EADDRNOTAVAIL;
 1418                 goto out_in6p_locked;
 1419         }
 1420 
 1421         INP_WLOCK_ASSERT(inp);
 1422 
 1423         /*
 1424          * Begin state merge transaction at socket layer.
 1425          */
 1426         if (doblock) {
 1427                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 1428                 ims = im6f_graft(imf, fmode, &ssa->sin6);
 1429                 if (ims == NULL)
 1430                         error = ENOMEM;
 1431         } else {
 1432                 CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 1433                 error = im6f_prune(imf, &ssa->sin6);
 1434         }
 1435 
 1436         if (error) {
 1437                 CTR1(KTR_MLD, "%s: merge imf state failed", __func__);
 1438                 goto out_im6f_rollback;
 1439         }
 1440 
 1441         /*
 1442          * Begin state merge transaction at MLD layer.
 1443          */
 1444         IN6_MULTI_LOCK();
 1445 
 1446         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1447         error = in6m_merge(inm, imf);
 1448         if (error) {
 1449                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1450                 goto out_im6f_rollback;
 1451         }
 1452 
 1453         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1454         error = mld_change_state(inm, 0);
 1455         if (error)
 1456                 CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1457 
 1458         IN6_MULTI_UNLOCK();
 1459 
 1460 out_im6f_rollback:
 1461         if (error)
 1462                 im6f_rollback(imf);
 1463         else
 1464                 im6f_commit(imf);
 1465 
 1466         im6f_reap(imf);
 1467 
 1468 out_in6p_locked:
 1469         INP_WUNLOCK(inp);
 1470         return (error);
 1471 }
 1472 
 1473 /*
 1474  * Given an inpcb, return its multicast options structure pointer.  Accepts
 1475  * an unlocked inpcb pointer, but will return it locked.  May sleep.
 1476  *
 1477  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 1478  * SMPng: NOTE: Returns with the INP write lock held.
 1479  */
 1480 static struct ip6_moptions *
 1481 in6p_findmoptions(struct inpcb *inp)
 1482 {
 1483         struct ip6_moptions      *imo;
 1484         struct in6_multi                **immp;
 1485         struct in6_mfilter       *imfp;
 1486         size_t                    idx;
 1487 
 1488         INP_WLOCK(inp);
 1489         if (inp->in6p_moptions != NULL)
 1490                 return (inp->in6p_moptions);
 1491 
 1492         INP_WUNLOCK(inp);
 1493 
 1494         imo = malloc(sizeof(*imo), M_IP6MOPTS, M_WAITOK);
 1495         immp = malloc(sizeof(*immp) * IPV6_MIN_MEMBERSHIPS, M_IP6MOPTS,
 1496             M_WAITOK | M_ZERO);
 1497         imfp = malloc(sizeof(struct in6_mfilter) * IPV6_MIN_MEMBERSHIPS,
 1498             M_IN6MFILTER, M_WAITOK);
 1499 
 1500         imo->im6o_multicast_ifp = NULL;
 1501         imo->im6o_multicast_hlim = V_ip6_defmcasthlim;
 1502         imo->im6o_multicast_loop = in6_mcast_loop;
 1503         imo->im6o_num_memberships = 0;
 1504         imo->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
 1505         imo->im6o_membership = immp;
 1506 
 1507         /* Initialize per-group source filters. */
 1508         for (idx = 0; idx < IPV6_MIN_MEMBERSHIPS; idx++)
 1509                 im6f_init(&imfp[idx], MCAST_UNDEFINED, MCAST_EXCLUDE);
 1510         imo->im6o_mfilters = imfp;
 1511 
 1512         INP_WLOCK(inp);
 1513         if (inp->in6p_moptions != NULL) {
 1514                 free(imfp, M_IN6MFILTER);
 1515                 free(immp, M_IP6MOPTS);
 1516                 free(imo, M_IP6MOPTS);
 1517                 return (inp->in6p_moptions);
 1518         }
 1519         inp->in6p_moptions = imo;
 1520         return (imo);
 1521 }
 1522 
 1523 /*
 1524  * Discard the IPv6 multicast options (and source filters).
 1525  *
 1526  * SMPng: NOTE: assumes INP write lock is held.
 1527  */
 1528 void
 1529 ip6_freemoptions(struct ip6_moptions *imo)
 1530 {
 1531         struct in6_mfilter      *imf;
 1532         size_t                   idx, nmships;
 1533 
 1534         KASSERT(imo != NULL, ("%s: ip6_moptions is NULL", __func__));
 1535 
 1536         nmships = imo->im6o_num_memberships;
 1537         for (idx = 0; idx < nmships; ++idx) {
 1538                 imf = imo->im6o_mfilters ? &imo->im6o_mfilters[idx] : NULL;
 1539                 if (imf)
 1540                         im6f_leave(imf);
 1541                 /* XXX this will thrash the lock(s) */
 1542                 (void)in6_mc_leave(imo->im6o_membership[idx], imf);
 1543                 if (imf)
 1544                         im6f_purge(imf);
 1545         }
 1546 
 1547         if (imo->im6o_mfilters)
 1548                 free(imo->im6o_mfilters, M_IN6MFILTER);
 1549         free(imo->im6o_membership, M_IP6MOPTS);
 1550         free(imo, M_IP6MOPTS);
 1551 }
 1552 
 1553 /*
 1554  * Atomically get source filters on a socket for an IPv6 multicast group.
 1555  * Called with INP lock held; returns with lock released.
 1556  */
 1557 static int
 1558 in6p_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
 1559 {
 1560         struct __msfilterreq     msfr;
 1561         sockunion_t             *gsa;
 1562         struct ifnet            *ifp;
 1563         struct ip6_moptions     *imo;
 1564         struct in6_mfilter      *imf;
 1565         struct ip6_msource      *ims;
 1566         struct in6_msource      *lims;
 1567         struct sockaddr_in6     *psin;
 1568         struct sockaddr_storage *ptss;
 1569         struct sockaddr_storage *tss;
 1570         int                      error;
 1571         size_t                   idx, nsrcs, ncsrcs;
 1572 
 1573         INP_WLOCK_ASSERT(inp);
 1574 
 1575         imo = inp->in6p_moptions;
 1576         KASSERT(imo != NULL, ("%s: null ip6_moptions", __func__));
 1577 
 1578         INP_WUNLOCK(inp);
 1579 
 1580         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 1581             sizeof(struct __msfilterreq));
 1582         if (error)
 1583                 return (error);
 1584 
 1585         if (msfr.msfr_group.ss_family != AF_INET6 ||
 1586             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 1587                 return (EINVAL);
 1588 
 1589         gsa = (sockunion_t *)&msfr.msfr_group;
 1590         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1591                 return (EINVAL);
 1592 
 1593         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 1594                 return (EADDRNOTAVAIL);
 1595         ifp = ifnet_byindex(msfr.msfr_ifindex);
 1596         if (ifp == NULL)
 1597                 return (EADDRNOTAVAIL);
 1598         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1599 
 1600         INP_WLOCK(inp);
 1601 
 1602         /*
 1603          * Lookup group on the socket.
 1604          */
 1605         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1606         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1607                 INP_WUNLOCK(inp);
 1608                 return (EADDRNOTAVAIL);
 1609         }
 1610         imf = &imo->im6o_mfilters[idx];
 1611 
 1612         /*
 1613          * Ignore memberships which are in limbo.
 1614          */
 1615         if (imf->im6f_st[1] == MCAST_UNDEFINED) {
 1616                 INP_WUNLOCK(inp);
 1617                 return (EAGAIN);
 1618         }
 1619         msfr.msfr_fmode = imf->im6f_st[1];
 1620 
 1621         /*
 1622          * If the user specified a buffer, copy out the source filter
 1623          * entries to userland gracefully.
 1624          * We only copy out the number of entries which userland
 1625          * has asked for, but we always tell userland how big the
 1626          * buffer really needs to be.
 1627          */
 1628         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 1629                 msfr.msfr_nsrcs = in6_mcast_maxsocksrc;
 1630         tss = NULL;
 1631         if (msfr.msfr_srcs != NULL && msfr.msfr_nsrcs > 0) {
 1632                 tss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 1633                     M_TEMP, M_NOWAIT | M_ZERO);
 1634                 if (tss == NULL) {
 1635                         INP_WUNLOCK(inp);
 1636                         return (ENOBUFS);
 1637                 }
 1638         }
 1639 
 1640         /*
 1641          * Count number of sources in-mode at t0.
 1642          * If buffer space exists and remains, copy out source entries.
 1643          */
 1644         nsrcs = msfr.msfr_nsrcs;
 1645         ncsrcs = 0;
 1646         ptss = tss;
 1647         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
 1648                 lims = (struct in6_msource *)ims;
 1649                 if (lims->im6sl_st[0] == MCAST_UNDEFINED ||
 1650                     lims->im6sl_st[0] != imf->im6f_st[0])
 1651                         continue;
 1652                 ++ncsrcs;
 1653                 if (tss != NULL && nsrcs > 0) {
 1654                         psin = (struct sockaddr_in6 *)ptss;
 1655                         psin->sin6_family = AF_INET6;
 1656                         psin->sin6_len = sizeof(struct sockaddr_in6);
 1657                         psin->sin6_addr = lims->im6s_addr;
 1658                         psin->sin6_port = 0;
 1659                         --nsrcs;
 1660                         ++ptss;
 1661                 }
 1662         }
 1663 
 1664         INP_WUNLOCK(inp);
 1665 
 1666         if (tss != NULL) {
 1667                 error = copyout(tss, msfr.msfr_srcs,
 1668                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 1669                 free(tss, M_TEMP);
 1670                 if (error)
 1671                         return (error);
 1672         }
 1673 
 1674         msfr.msfr_nsrcs = ncsrcs;
 1675         error = sooptcopyout(sopt, &msfr, sizeof(struct __msfilterreq));
 1676 
 1677         return (error);
 1678 }
 1679 
 1680 /*
 1681  * Return the IP multicast options in response to user getsockopt().
 1682  */
 1683 int
 1684 ip6_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 1685 {
 1686         struct ip6_moptions     *im6o;
 1687         int                      error;
 1688         u_int                    optval;
 1689 
 1690         INP_WLOCK(inp);
 1691         im6o = inp->in6p_moptions;
 1692         /*
 1693          * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 1694          * or is a divert socket, reject it.
 1695          */
 1696         if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
 1697             (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
 1698             inp->inp_socket->so_proto->pr_type != SOCK_DGRAM)) {
 1699                 INP_WUNLOCK(inp);
 1700                 return (EOPNOTSUPP);
 1701         }
 1702 
 1703         error = 0;
 1704         switch (sopt->sopt_name) {
 1705         case IPV6_MULTICAST_IF:
 1706                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL) {
 1707                         optval = 0;
 1708                 } else {
 1709                         optval = im6o->im6o_multicast_ifp->if_index;
 1710                 }
 1711                 INP_WUNLOCK(inp);
 1712                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1713                 break;
 1714 
 1715         case IPV6_MULTICAST_HOPS:
 1716                 if (im6o == NULL)
 1717                         optval = V_ip6_defmcasthlim;
 1718                 else
 1719                         optval = im6o->im6o_multicast_hlim;
 1720                 INP_WUNLOCK(inp);
 1721                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1722                 break;
 1723 
 1724         case IPV6_MULTICAST_LOOP:
 1725                 if (im6o == NULL)
 1726                         optval = in6_mcast_loop; /* XXX VIMAGE */
 1727                 else
 1728                         optval = im6o->im6o_multicast_loop;
 1729                 INP_WUNLOCK(inp);
 1730                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1731                 break;
 1732 
 1733         case IPV6_MSFILTER:
 1734                 if (im6o == NULL) {
 1735                         error = EADDRNOTAVAIL;
 1736                         INP_WUNLOCK(inp);
 1737                 } else {
 1738                         error = in6p_get_source_filters(inp, sopt);
 1739                 }
 1740                 break;
 1741 
 1742         default:
 1743                 INP_WUNLOCK(inp);
 1744                 error = ENOPROTOOPT;
 1745                 break;
 1746         }
 1747 
 1748         INP_UNLOCK_ASSERT(inp);
 1749 
 1750         return (error);
 1751 }
 1752 
 1753 /*
 1754  * Look up the ifnet to use for a multicast group membership,
 1755  * given the address of an IPv6 group.
 1756  *
 1757  * This routine exists to support legacy IPv6 multicast applications.
 1758  *
 1759  * If inp is non-NULL, use this socket's current FIB number for any
 1760  * required FIB lookup. Look up the group address in the unicast FIB,
 1761  * and use its ifp; usually, this points to the default next-hop.
 1762  * If the FIB lookup fails, return NULL.
 1763  *
 1764  * FUTURE: Support multiple forwarding tables for IPv6.
 1765  *
 1766  * Returns NULL if no ifp could be found.
 1767  */
 1768 static struct ifnet *
 1769 in6p_lookup_mcast_ifp(const struct inpcb *in6p,
 1770     const struct sockaddr_in6 *gsin6)
 1771 {
 1772         struct route_in6         ro6;
 1773         struct ifnet            *ifp;
 1774 
 1775         KASSERT(in6p->inp_vflag & INP_IPV6,
 1776             ("%s: not INP_IPV6 inpcb", __func__));
 1777         KASSERT(gsin6->sin6_family == AF_INET6,
 1778             ("%s: not AF_INET6 group", __func__));
 1779         KASSERT(IN6_IS_ADDR_MULTICAST(&gsin6->sin6_addr),
 1780             ("%s: not multicast", __func__));
 1781 
 1782         ifp = NULL;
 1783         memset(&ro6, 0, sizeof(struct route_in6));
 1784         memcpy(&ro6.ro_dst, gsin6, sizeof(struct sockaddr_in6));
 1785         rtalloc_ign_fib((struct route *)&ro6, 0,
 1786             in6p ? in6p->inp_inc.inc_fibnum : RT_DEFAULT_FIB);
 1787         if (ro6.ro_rt != NULL) {
 1788                 ifp = ro6.ro_rt->rt_ifp;
 1789                 KASSERT(ifp != NULL, ("%s: null ifp", __func__));
 1790                 RTFREE(ro6.ro_rt);
 1791         }
 1792 
 1793         return (ifp);
 1794 }
 1795 
 1796 /*
 1797  * Join an IPv6 multicast group, possibly with a source.
 1798  *
 1799  * FIXME: The KAME use of the unspecified address (::)
 1800  * to join *all* multicast groups is currently unsupported.
 1801  */
 1802 static int
 1803 in6p_join_group(struct inpcb *inp, struct sockopt *sopt)
 1804 {
 1805         struct group_source_req          gsr;
 1806         sockunion_t                     *gsa, *ssa;
 1807         struct ifnet                    *ifp;
 1808         struct in6_mfilter              *imf;
 1809         struct ip6_moptions             *imo;
 1810         struct in6_multi                *inm;
 1811         struct in6_msource              *lims;
 1812         size_t                           idx;
 1813         int                              error, is_new;
 1814 
 1815         ifp = NULL;
 1816         imf = NULL;
 1817         lims = NULL;
 1818         error = 0;
 1819         is_new = 0;
 1820 
 1821         memset(&gsr, 0, sizeof(struct group_source_req));
 1822         gsa = (sockunion_t *)&gsr.gsr_group;
 1823         gsa->ss.ss_family = AF_UNSPEC;
 1824         ssa = (sockunion_t *)&gsr.gsr_source;
 1825         ssa->ss.ss_family = AF_UNSPEC;
 1826 
 1827         /*
 1828          * Chew everything into struct group_source_req.
 1829          * Overwrite the port field if present, as the sockaddr
 1830          * being copied in may be matched with a binary comparison.
 1831          * Ignore passed-in scope ID.
 1832          */
 1833         switch (sopt->sopt_name) {
 1834         case IPV6_JOIN_GROUP: {
 1835                 struct ipv6_mreq mreq;
 1836 
 1837                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 1838                     sizeof(struct ipv6_mreq));
 1839                 if (error)
 1840                         return (error);
 1841 
 1842                 gsa->sin6.sin6_family = AF_INET6;
 1843                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 1844                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 1845 
 1846                 if (mreq.ipv6mr_interface == 0) {
 1847                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 1848                 } else {
 1849                         if (mreq.ipv6mr_interface < 0 ||
 1850                             V_if_index < mreq.ipv6mr_interface)
 1851                                 return (EADDRNOTAVAIL);
 1852                         ifp = ifnet_byindex(mreq.ipv6mr_interface);
 1853                 }
 1854                 CTR3(KTR_MLD, "%s: ipv6mr_interface = %d, ifp = %p",
 1855                     __func__, mreq.ipv6mr_interface, ifp);
 1856         } break;
 1857 
 1858         case MCAST_JOIN_GROUP:
 1859         case MCAST_JOIN_SOURCE_GROUP:
 1860                 if (sopt->sopt_name == MCAST_JOIN_GROUP) {
 1861                         error = sooptcopyin(sopt, &gsr,
 1862                             sizeof(struct group_req),
 1863                             sizeof(struct group_req));
 1864                 } else if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1865                         error = sooptcopyin(sopt, &gsr,
 1866                             sizeof(struct group_source_req),
 1867                             sizeof(struct group_source_req));
 1868                 }
 1869                 if (error)
 1870                         return (error);
 1871 
 1872                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1873                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1874                         return (EINVAL);
 1875 
 1876                 if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1877                         if (ssa->sin6.sin6_family != AF_INET6 ||
 1878                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1879                                 return (EINVAL);
 1880                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 1881                                 return (EINVAL);
 1882                         /*
 1883                          * TODO: Validate embedded scope ID in source
 1884                          * list entry against passed-in ifp, if and only
 1885                          * if source list filter entry is iface or node local.
 1886                          */
 1887                         in6_clearscope(&ssa->sin6.sin6_addr);
 1888                         ssa->sin6.sin6_port = 0;
 1889                         ssa->sin6.sin6_scope_id = 0;
 1890                 }
 1891 
 1892                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1893                         return (EADDRNOTAVAIL);
 1894                 ifp = ifnet_byindex(gsr.gsr_interface);
 1895                 break;
 1896 
 1897         default:
 1898                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1899                     __func__, sopt->sopt_name);
 1900                 return (EOPNOTSUPP);
 1901                 break;
 1902         }
 1903 
 1904         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1905                 return (EINVAL);
 1906 
 1907         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
 1908                 return (EADDRNOTAVAIL);
 1909 
 1910         gsa->sin6.sin6_port = 0;
 1911         gsa->sin6.sin6_scope_id = 0;
 1912 
 1913         /*
 1914          * Always set the scope zone ID on memberships created from userland.
 1915          * Use the passed-in ifp to do this.
 1916          * XXX The in6_setscope() return value is meaningless.
 1917          * XXX SCOPE6_LOCK() is taken by in6_setscope().
 1918          */
 1919         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1920 
 1921         imo = in6p_findmoptions(inp);
 1922         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1923         if (idx == -1) {
 1924                 is_new = 1;
 1925         } else {
 1926                 inm = imo->im6o_membership[idx];
 1927                 imf = &imo->im6o_mfilters[idx];
 1928                 if (ssa->ss.ss_family != AF_UNSPEC) {
 1929                         /*
 1930                          * MCAST_JOIN_SOURCE_GROUP on an exclusive membership
 1931                          * is an error. On an existing inclusive membership,
 1932                          * it just adds the source to the filter list.
 1933                          */
 1934                         if (imf->im6f_st[1] != MCAST_INCLUDE) {
 1935                                 error = EINVAL;
 1936                                 goto out_in6p_locked;
 1937                         }
 1938                         /*
 1939                          * Throw out duplicates.
 1940                          *
 1941                          * XXX FIXME: This makes a naive assumption that
 1942                          * even if entries exist for *ssa in this imf,
 1943                          * they will be rejected as dupes, even if they
 1944                          * are not valid in the current mode (in-mode).
 1945                          *
 1946                          * in6_msource is transactioned just as for anything
 1947                          * else in SSM -- but note naive use of in6m_graft()
 1948                          * below for allocating new filter entries.
 1949                          *
 1950                          * This is only an issue if someone mixes the
 1951                          * full-state SSM API with the delta-based API,
 1952                          * which is discouraged in the relevant RFCs.
 1953                          */
 1954                         lims = im6o_match_source(imo, idx, &ssa->sa);
 1955                         if (lims != NULL /*&&
 1956                             lims->im6sl_st[1] == MCAST_INCLUDE*/) {
 1957                                 error = EADDRNOTAVAIL;
 1958                                 goto out_in6p_locked;
 1959                         }
 1960                 } else {
 1961                         /*
 1962                          * MCAST_JOIN_GROUP alone, on any existing membership,
 1963                          * is rejected, to stop the same inpcb tying up
 1964                          * multiple refs to the in_multi.
 1965                          * On an existing inclusive membership, this is also
 1966                          * an error; if you want to change filter mode,
 1967                          * you must use the userland API setsourcefilter().
 1968                          * XXX We don't reject this for imf in UNDEFINED
 1969                          * state at t1, because allocation of a filter
 1970                          * is atomic with allocation of a membership.
 1971                          */
 1972                         error = EINVAL;
 1973                         goto out_in6p_locked;
 1974                 }
 1975         }
 1976 
 1977         /*
 1978          * Begin state merge transaction at socket layer.
 1979          */
 1980         INP_WLOCK_ASSERT(inp);
 1981 
 1982         if (is_new) {
 1983                 if (imo->im6o_num_memberships == imo->im6o_max_memberships) {
 1984                         error = im6o_grow(imo);
 1985                         if (error)
 1986                                 goto out_in6p_locked;
 1987                 }
 1988                 /*
 1989                  * Allocate the new slot upfront so we can deal with
 1990                  * grafting the new source filter in same code path
 1991                  * as for join-source on existing membership.
 1992                  */
 1993                 idx = imo->im6o_num_memberships;
 1994                 imo->im6o_membership[idx] = NULL;
 1995                 imo->im6o_num_memberships++;
 1996                 KASSERT(imo->im6o_mfilters != NULL,
 1997                     ("%s: im6f_mfilters vector was not allocated", __func__));
 1998                 imf = &imo->im6o_mfilters[idx];
 1999                 KASSERT(RB_EMPTY(&imf->im6f_sources),
 2000                     ("%s: im6f_sources not empty", __func__));
 2001         }
 2002 
 2003         /*
 2004          * Graft new source into filter list for this inpcb's
 2005          * membership of the group. The in6_multi may not have
 2006          * been allocated yet if this is a new membership, however,
 2007          * the in_mfilter slot will be allocated and must be initialized.
 2008          *
 2009          * Note: Grafting of exclusive mode filters doesn't happen
 2010          * in this path.
 2011          * XXX: Should check for non-NULL lims (node exists but may
 2012          * not be in-mode) for interop with full-state API.
 2013          */
 2014         if (ssa->ss.ss_family != AF_UNSPEC) {
 2015                 /* Membership starts in IN mode */
 2016                 if (is_new) {
 2017                         CTR1(KTR_MLD, "%s: new join w/source", __func__);
 2018                         im6f_init(imf, MCAST_UNDEFINED, MCAST_INCLUDE);
 2019                 } else {
 2020                         CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 2021                 }
 2022                 lims = im6f_graft(imf, MCAST_INCLUDE, &ssa->sin6);
 2023                 if (lims == NULL) {
 2024                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2025                             __func__);
 2026                         error = ENOMEM;
 2027                         goto out_im6o_free;
 2028                 }
 2029         } else {
 2030                 /* No address specified; Membership starts in EX mode */
 2031                 if (is_new) {
 2032                         CTR1(KTR_MLD, "%s: new join w/o source", __func__);
 2033                         im6f_init(imf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 2034                 }
 2035         }
 2036 
 2037         /*
 2038          * Begin state merge transaction at MLD layer.
 2039          */
 2040         IN6_MULTI_LOCK();
 2041 
 2042         if (is_new) {
 2043                 error = in6_mc_join_locked(ifp, &gsa->sin6.sin6_addr, imf,
 2044                     &inm, 0);
 2045                 if (error)
 2046                         goto out_im6o_free;
 2047                 imo->im6o_membership[idx] = inm;
 2048         } else {
 2049                 CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2050                 error = in6m_merge(inm, imf);
 2051                 if (error) {
 2052                         CTR1(KTR_MLD, "%s: failed to merge inm state",
 2053                             __func__);
 2054                         goto out_im6f_rollback;
 2055                 }
 2056                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2057                 error = mld_change_state(inm, 0);
 2058                 if (error) {
 2059                         CTR1(KTR_MLD, "%s: failed mld downcall",
 2060                             __func__);
 2061                         goto out_im6f_rollback;
 2062                 }
 2063         }
 2064 
 2065         IN6_MULTI_UNLOCK();
 2066 
 2067 out_im6f_rollback:
 2068         INP_WLOCK_ASSERT(inp);
 2069         if (error) {
 2070                 im6f_rollback(imf);
 2071                 if (is_new)
 2072                         im6f_purge(imf);
 2073                 else
 2074                         im6f_reap(imf);
 2075         } else {
 2076                 im6f_commit(imf);
 2077         }
 2078 
 2079 out_im6o_free:
 2080         if (error && is_new) {
 2081                 imo->im6o_membership[idx] = NULL;
 2082                 --imo->im6o_num_memberships;
 2083         }
 2084 
 2085 out_in6p_locked:
 2086         INP_WUNLOCK(inp);
 2087         return (error);
 2088 }
 2089 
 2090 /*
 2091  * Leave an IPv6 multicast group on an inpcb, possibly with a source.
 2092  */
 2093 static int
 2094 in6p_leave_group(struct inpcb *inp, struct sockopt *sopt)
 2095 {
 2096         struct ipv6_mreq                 mreq;
 2097         struct group_source_req          gsr;
 2098         sockunion_t                     *gsa, *ssa;
 2099         struct ifnet                    *ifp;
 2100         struct in6_mfilter              *imf;
 2101         struct ip6_moptions             *imo;
 2102         struct in6_msource              *ims;
 2103         struct in6_multi                *inm;
 2104         uint32_t                         ifindex;
 2105         size_t                           idx;
 2106         int                              error, is_final;
 2107 #ifdef KTR
 2108         char                             ip6tbuf[INET6_ADDRSTRLEN];
 2109 #endif
 2110 
 2111         ifp = NULL;
 2112         ifindex = 0;
 2113         error = 0;
 2114         is_final = 1;
 2115 
 2116         memset(&gsr, 0, sizeof(struct group_source_req));
 2117         gsa = (sockunion_t *)&gsr.gsr_group;
 2118         gsa->ss.ss_family = AF_UNSPEC;
 2119         ssa = (sockunion_t *)&gsr.gsr_source;
 2120         ssa->ss.ss_family = AF_UNSPEC;
 2121 
 2122         /*
 2123          * Chew everything passed in up into a struct group_source_req
 2124          * as that is easier to process.
 2125          * Note: Any embedded scope ID in the multicast group passed
 2126          * in by userland is ignored, the interface index is the recommended
 2127          * mechanism to specify an interface; see below.
 2128          */
 2129         switch (sopt->sopt_name) {
 2130         case IPV6_LEAVE_GROUP:
 2131                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 2132                     sizeof(struct ipv6_mreq));
 2133                 if (error)
 2134                         return (error);
 2135                 gsa->sin6.sin6_family = AF_INET6;
 2136                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 2137                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 2138                 gsa->sin6.sin6_port = 0;
 2139                 gsa->sin6.sin6_scope_id = 0;
 2140                 ifindex = mreq.ipv6mr_interface;
 2141                 break;
 2142 
 2143         case MCAST_LEAVE_GROUP:
 2144         case MCAST_LEAVE_SOURCE_GROUP:
 2145                 if (sopt->sopt_name == MCAST_LEAVE_GROUP) {
 2146                         error = sooptcopyin(sopt, &gsr,
 2147                             sizeof(struct group_req),
 2148                             sizeof(struct group_req));
 2149                 } else if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2150                         error = sooptcopyin(sopt, &gsr,
 2151                             sizeof(struct group_source_req),
 2152                             sizeof(struct group_source_req));
 2153                 }
 2154                 if (error)
 2155                         return (error);
 2156 
 2157                 if (gsa->sin6.sin6_family != AF_INET6 ||
 2158                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2159                         return (EINVAL);
 2160                 if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2161                         if (ssa->sin6.sin6_family != AF_INET6 ||
 2162                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2163                                 return (EINVAL);
 2164                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 2165                                 return (EINVAL);
 2166                         /*
 2167                          * TODO: Validate embedded scope ID in source
 2168                          * list entry against passed-in ifp, if and only
 2169                          * if source list filter entry is iface or node local.
 2170                          */
 2171                         in6_clearscope(&ssa->sin6.sin6_addr);
 2172                 }
 2173                 gsa->sin6.sin6_port = 0;
 2174                 gsa->sin6.sin6_scope_id = 0;
 2175                 ifindex = gsr.gsr_interface;
 2176                 break;
 2177 
 2178         default:
 2179                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 2180                     __func__, sopt->sopt_name);
 2181                 return (EOPNOTSUPP);
 2182                 break;
 2183         }
 2184 
 2185         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2186                 return (EINVAL);
 2187 
 2188         /*
 2189          * Validate interface index if provided. If no interface index
 2190          * was provided separately, attempt to look the membership up
 2191          * from the default scope as a last resort to disambiguate
 2192          * the membership we are being asked to leave.
 2193          * XXX SCOPE6 lock potentially taken here.
 2194          */
 2195         if (ifindex != 0) {
 2196                 if (ifindex < 0 || V_if_index < ifindex)
 2197                         return (EADDRNOTAVAIL);
 2198                 ifp = ifnet_byindex(ifindex);
 2199                 if (ifp == NULL)
 2200                         return (EADDRNOTAVAIL);
 2201                 (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2202         } else {
 2203                 error = sa6_embedscope(&gsa->sin6, V_ip6_use_defzone);
 2204                 if (error)
 2205                         return (EADDRNOTAVAIL);
 2206                 /*
 2207                  * Some badly behaved applications don't pass an ifindex
 2208                  * or a scope ID, which is an API violation. In this case,
 2209                  * perform a lookup as per a v6 join.
 2210                  *
 2211                  * XXX For now, stomp on zone ID for the corner case.
 2212                  * This is not the 'KAME way', but we need to see the ifp
 2213                  * directly until such time as this implementation is
 2214                  * refactored, assuming the scope IDs are the way to go.
 2215                  */
 2216                 ifindex = ntohs(gsa->sin6.sin6_addr.s6_addr16[1]);
 2217                 if (ifindex == 0) {
 2218                         CTR2(KTR_MLD, "%s: warning: no ifindex, looking up "
 2219                             "ifp for group %s.", __func__,
 2220                             ip6_sprintf(ip6tbuf, &gsa->sin6.sin6_addr));
 2221                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 2222                 } else {
 2223                         ifp = ifnet_byindex(ifindex);
 2224                 }
 2225                 if (ifp == NULL)
 2226                         return (EADDRNOTAVAIL);
 2227         }
 2228 
 2229         CTR2(KTR_MLD, "%s: ifp = %p", __func__, ifp);
 2230         KASSERT(ifp != NULL, ("%s: ifp did not resolve", __func__));
 2231 
 2232         /*
 2233          * Find the membership in the membership array.
 2234          */
 2235         imo = in6p_findmoptions(inp);
 2236         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2237         if (idx == -1) {
 2238                 error = EADDRNOTAVAIL;
 2239                 goto out_in6p_locked;
 2240         }
 2241         inm = imo->im6o_membership[idx];
 2242         imf = &imo->im6o_mfilters[idx];
 2243 
 2244         if (ssa->ss.ss_family != AF_UNSPEC)
 2245                 is_final = 0;
 2246 
 2247         /*
 2248          * Begin state merge transaction at socket layer.
 2249          */
 2250         INP_WLOCK_ASSERT(inp);
 2251 
 2252         /*
 2253          * If we were instructed only to leave a given source, do so.
 2254          * MCAST_LEAVE_SOURCE_GROUP is only valid for inclusive memberships.
 2255          */
 2256         if (is_final) {
 2257                 im6f_leave(imf);
 2258         } else {
 2259                 if (imf->im6f_st[0] == MCAST_EXCLUDE) {
 2260                         error = EADDRNOTAVAIL;
 2261                         goto out_in6p_locked;
 2262                 }
 2263                 ims = im6o_match_source(imo, idx, &ssa->sa);
 2264                 if (ims == NULL) {
 2265                         CTR3(KTR_MLD, "%s: source %p %spresent", __func__,
 2266                             ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 2267                             "not ");
 2268                         error = EADDRNOTAVAIL;
 2269                         goto out_in6p_locked;
 2270                 }
 2271                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 2272                 error = im6f_prune(imf, &ssa->sin6);
 2273                 if (error) {
 2274                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2275                             __func__);
 2276                         goto out_in6p_locked;
 2277                 }
 2278         }
 2279 
 2280         /*
 2281          * Begin state merge transaction at MLD layer.
 2282          */
 2283         IN6_MULTI_LOCK();
 2284 
 2285         if (is_final) {
 2286                 /*
 2287                  * Give up the multicast address record to which
 2288                  * the membership points.
 2289                  */
 2290                 (void)in6_mc_leave_locked(inm, imf);
 2291         } else {
 2292                 CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2293                 error = in6m_merge(inm, imf);
 2294                 if (error) {
 2295                         CTR1(KTR_MLD, "%s: failed to merge inm state",
 2296                             __func__);
 2297                         goto out_im6f_rollback;
 2298                 }
 2299 
 2300                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2301                 error = mld_change_state(inm, 0);
 2302                 if (error) {
 2303                         CTR1(KTR_MLD, "%s: failed mld downcall",
 2304                             __func__);
 2305                 }
 2306         }
 2307 
 2308         IN6_MULTI_UNLOCK();
 2309 
 2310 out_im6f_rollback:
 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 
 2357         ifp = ifnet_byindex(ifindex);
 2358         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
 2359                 return (EADDRNOTAVAIL);
 2360 
 2361         imo = in6p_findmoptions(inp);
 2362         imo->im6o_multicast_ifp = ifp;
 2363         INP_WUNLOCK(inp);
 2364 
 2365         return (0);
 2366 }
 2367 
 2368 /*
 2369  * Atomically set source filters on a socket for an IPv6 multicast group.
 2370  *
 2371  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 2372  */
 2373 static int
 2374 in6p_set_source_filters(struct inpcb *inp, struct sockopt *sopt)
 2375 {
 2376         struct __msfilterreq     msfr;
 2377         sockunion_t             *gsa;
 2378         struct ifnet            *ifp;
 2379         struct in6_mfilter      *imf;
 2380         struct ip6_moptions     *imo;
 2381         struct in6_multi                *inm;
 2382         size_t                   idx;
 2383         int                      error;
 2384 
 2385         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 2386             sizeof(struct __msfilterreq));
 2387         if (error)
 2388                 return (error);
 2389 
 2390         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 2391                 return (ENOBUFS);
 2392 
 2393         if (msfr.msfr_fmode != MCAST_EXCLUDE &&
 2394             msfr.msfr_fmode != MCAST_INCLUDE)
 2395                 return (EINVAL);
 2396 
 2397         if (msfr.msfr_group.ss_family != AF_INET6 ||
 2398             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 2399                 return (EINVAL);
 2400 
 2401         gsa = (sockunion_t *)&msfr.msfr_group;
 2402         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2403                 return (EINVAL);
 2404 
 2405         gsa->sin6.sin6_port = 0;        /* ignore port */
 2406 
 2407         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 2408                 return (EADDRNOTAVAIL);
 2409         ifp = ifnet_byindex(msfr.msfr_ifindex);
 2410         if (ifp == NULL)
 2411                 return (EADDRNOTAVAIL);
 2412         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2413 
 2414         /*
 2415          * Take the INP write lock.
 2416          * Check if this socket is a member of this group.
 2417          */
 2418         imo = in6p_findmoptions(inp);
 2419         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2420         if (idx == -1 || imo->im6o_mfilters == NULL) {
 2421                 error = EADDRNOTAVAIL;
 2422                 goto out_in6p_locked;
 2423         }
 2424         inm = imo->im6o_membership[idx];
 2425         imf = &imo->im6o_mfilters[idx];
 2426 
 2427         /*
 2428          * Begin state merge transaction at socket layer.
 2429          */
 2430         INP_WLOCK_ASSERT(inp);
 2431 
 2432         imf->im6f_st[1] = msfr.msfr_fmode;
 2433 
 2434         /*
 2435          * Apply any new source filters, if present.
 2436          * Make a copy of the user-space source vector so
 2437          * that we may copy them with a single copyin. This
 2438          * allows us to deal with page faults up-front.
 2439          */
 2440         if (msfr.msfr_nsrcs > 0) {
 2441                 struct in6_msource      *lims;
 2442                 struct sockaddr_in6     *psin;
 2443                 struct sockaddr_storage *kss, *pkss;
 2444                 int                      i;
 2445 
 2446                 INP_WUNLOCK(inp);
 2447  
 2448                 CTR2(KTR_MLD, "%s: loading %lu source list entries",
 2449                     __func__, (unsigned long)msfr.msfr_nsrcs);
 2450                 kss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 2451                     M_TEMP, M_WAITOK);
 2452                 error = copyin(msfr.msfr_srcs, kss,
 2453                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 2454                 if (error) {
 2455                         free(kss, M_TEMP);
 2456                         return (error);
 2457                 }
 2458 
 2459                 INP_WLOCK(inp);
 2460 
 2461                 /*
 2462                  * Mark all source filters as UNDEFINED at t1.
 2463                  * Restore new group filter mode, as im6f_leave()
 2464                  * will set it to INCLUDE.
 2465                  */
 2466                 im6f_leave(imf);
 2467                 imf->im6f_st[1] = msfr.msfr_fmode;
 2468 
 2469                 /*
 2470                  * Update socket layer filters at t1, lazy-allocating
 2471                  * new entries. This saves a bunch of memory at the
 2472                  * cost of one RB_FIND() per source entry; duplicate
 2473                  * entries in the msfr_nsrcs vector are ignored.
 2474                  * If we encounter an error, rollback transaction.
 2475                  *
 2476                  * XXX This too could be replaced with a set-symmetric
 2477                  * difference like loop to avoid walking from root
 2478                  * every time, as the key space is common.
 2479                  */
 2480                 for (i = 0, pkss = kss; i < msfr.msfr_nsrcs; i++, pkss++) {
 2481                         psin = (struct sockaddr_in6 *)pkss;
 2482                         if (psin->sin6_family != AF_INET6) {
 2483                                 error = EAFNOSUPPORT;
 2484                                 break;
 2485                         }
 2486                         if (psin->sin6_len != sizeof(struct sockaddr_in6)) {
 2487                                 error = EINVAL;
 2488                                 break;
 2489                         }
 2490                         if (IN6_IS_ADDR_MULTICAST(&psin->sin6_addr)) {
 2491                                 error = EINVAL;
 2492                                 break;
 2493                         }
 2494                         /*
 2495                          * TODO: Validate embedded scope ID in source
 2496                          * list entry against passed-in ifp, if and only
 2497                          * if source list filter entry is iface or node local.
 2498                          */
 2499                         in6_clearscope(&psin->sin6_addr);
 2500                         error = im6f_get_source(imf, psin, &lims);
 2501                         if (error)
 2502                                 break;
 2503                         lims->im6sl_st[1] = imf->im6f_st[1];
 2504                 }
 2505                 free(kss, M_TEMP);
 2506         }
 2507 
 2508         if (error)
 2509                 goto out_im6f_rollback;
 2510 
 2511         INP_WLOCK_ASSERT(inp);
 2512         IN6_MULTI_LOCK();
 2513 
 2514         /*
 2515          * Begin state merge transaction at MLD layer.
 2516          */
 2517         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2518         error = in6m_merge(inm, imf);
 2519         if (error) {
 2520                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 2521                 goto out_im6f_rollback;
 2522         }
 2523 
 2524         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2525         error = mld_change_state(inm, 0);
 2526         if (error)
 2527                 CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 2528 
 2529         IN6_MULTI_UNLOCK();
 2530 
 2531 out_im6f_rollback:
 2532         if (error)
 2533                 im6f_rollback(imf);
 2534         else
 2535                 im6f_commit(imf);
 2536 
 2537         im6f_reap(imf);
 2538 
 2539 out_in6p_locked:
 2540         INP_WUNLOCK(inp);
 2541         return (error);
 2542 }
 2543 
 2544 /*
 2545  * Set the IP multicast options in response to user setsockopt().
 2546  *
 2547  * Many of the socket options handled in this function duplicate the
 2548  * functionality of socket options in the regular unicast API. However,
 2549  * it is not possible to merge the duplicate code, because the idempotence
 2550  * of the IPv6 multicast part of the BSD Sockets API must be preserved;
 2551  * the effects of these options must be treated as separate and distinct.
 2552  *
 2553  * SMPng: XXX: Unlocked read of inp_socket believed OK.
 2554  */
 2555 int
 2556 ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 2557 {
 2558         struct ip6_moptions     *im6o;
 2559         int                      error;
 2560 
 2561         error = 0;
 2562 
 2563         /*
 2564          * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 2565          * or is a divert socket, reject it.
 2566          */
 2567         if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
 2568             (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
 2569              inp->inp_socket->so_proto->pr_type != SOCK_DGRAM))
 2570                 return (EOPNOTSUPP);
 2571 
 2572         switch (sopt->sopt_name) {
 2573         case IPV6_MULTICAST_IF:
 2574                 error = in6p_set_multicast_if(inp, sopt);
 2575                 break;
 2576 
 2577         case IPV6_MULTICAST_HOPS: {
 2578                 int hlim;
 2579 
 2580                 if (sopt->sopt_valsize != sizeof(int)) {
 2581                         error = EINVAL;
 2582                         break;
 2583                 }
 2584                 error = sooptcopyin(sopt, &hlim, sizeof(hlim), sizeof(int));
 2585                 if (error)
 2586                         break;
 2587                 if (hlim < -1 || hlim > 255) {
 2588                         error = EINVAL;
 2589                         break;
 2590                 } else if (hlim == -1) {
 2591                         hlim = V_ip6_defmcasthlim;
 2592                 }
 2593                 im6o = in6p_findmoptions(inp);
 2594                 im6o->im6o_multicast_hlim = hlim;
 2595                 INP_WUNLOCK(inp);
 2596                 break;
 2597         }
 2598 
 2599         case IPV6_MULTICAST_LOOP: {
 2600                 u_int loop;
 2601 
 2602                 /*
 2603                  * Set the loopback flag for outgoing multicast packets.
 2604                  * Must be zero or one.
 2605                  */
 2606                 if (sopt->sopt_valsize != sizeof(u_int)) {
 2607                         error = EINVAL;
 2608                         break;
 2609                 }
 2610                 error = sooptcopyin(sopt, &loop, sizeof(u_int), sizeof(u_int));
 2611                 if (error)
 2612                         break;
 2613                 if (loop > 1) {
 2614                         error = EINVAL;
 2615                         break;
 2616                 }
 2617                 im6o = in6p_findmoptions(inp);
 2618                 im6o->im6o_multicast_loop = loop;
 2619                 INP_WUNLOCK(inp);
 2620                 break;
 2621         }
 2622 
 2623         case IPV6_JOIN_GROUP:
 2624         case MCAST_JOIN_GROUP:
 2625         case MCAST_JOIN_SOURCE_GROUP:
 2626                 error = in6p_join_group(inp, sopt);
 2627                 break;
 2628 
 2629         case IPV6_LEAVE_GROUP:
 2630         case MCAST_LEAVE_GROUP:
 2631         case MCAST_LEAVE_SOURCE_GROUP:
 2632                 error = in6p_leave_group(inp, sopt);
 2633                 break;
 2634 
 2635         case MCAST_BLOCK_SOURCE:
 2636         case MCAST_UNBLOCK_SOURCE:
 2637                 error = in6p_block_unblock_source(inp, sopt);
 2638                 break;
 2639 
 2640         case IPV6_MSFILTER:
 2641                 error = in6p_set_source_filters(inp, sopt);
 2642                 break;
 2643 
 2644         default:
 2645                 error = EOPNOTSUPP;
 2646                 break;
 2647         }
 2648 
 2649         INP_UNLOCK_ASSERT(inp);
 2650 
 2651         return (error);
 2652 }
 2653 
 2654 /*
 2655  * Expose MLD's multicast filter mode and source list(s) to userland,
 2656  * keyed by (ifindex, group).
 2657  * The filter mode is written out as a uint32_t, followed by
 2658  * 0..n of struct in6_addr.
 2659  * For use by ifmcstat(8).
 2660  * SMPng: NOTE: unlocked read of ifindex space.
 2661  */
 2662 static int
 2663 sysctl_ip6_mcast_filters(SYSCTL_HANDLER_ARGS)
 2664 {
 2665         struct in6_addr                  mcaddr;
 2666         struct in6_addr                  src;
 2667         struct ifnet                    *ifp;
 2668         struct ifmultiaddr              *ifma;
 2669         struct in6_multi                *inm;
 2670         struct ip6_msource              *ims;
 2671         int                             *name;
 2672         int                              retval;
 2673         u_int                            namelen;
 2674         uint32_t                         fmode, ifindex;
 2675 #ifdef KTR
 2676         char                             ip6tbuf[INET6_ADDRSTRLEN];
 2677 #endif
 2678 
 2679         name = (int *)arg1;
 2680         namelen = arg2;
 2681 
 2682         if (req->newptr != NULL)
 2683                 return (EPERM);
 2684 
 2685         /* int: ifindex + 4 * 32 bits of IPv6 address */
 2686         if (namelen != 5)
 2687                 return (EINVAL);
 2688 
 2689         ifindex = name[0];
 2690         if (ifindex <= 0 || ifindex > V_if_index) {
 2691                 CTR2(KTR_MLD, "%s: ifindex %u out of range",
 2692                     __func__, ifindex);
 2693                 return (ENOENT);
 2694         }
 2695 
 2696         memcpy(&mcaddr, &name[1], sizeof(struct in6_addr));
 2697         if (!IN6_IS_ADDR_MULTICAST(&mcaddr)) {
 2698                 CTR2(KTR_MLD, "%s: group %s is not multicast",
 2699                     __func__, ip6_sprintf(ip6tbuf, &mcaddr));
 2700                 return (EINVAL);
 2701         }
 2702 
 2703         ifp = ifnet_byindex(ifindex);
 2704         if (ifp == NULL) {
 2705                 CTR2(KTR_MLD, "%s: no ifp for ifindex %u",
 2706                     __func__, ifindex);
 2707                 return (ENOENT);
 2708         }
 2709         /*
 2710          * Internal MLD lookups require that scope/zone ID is set.
 2711          */
 2712         (void)in6_setscope(&mcaddr, ifp, NULL);
 2713 
 2714         retval = sysctl_wire_old_buffer(req,
 2715             sizeof(uint32_t) + (in6_mcast_maxgrpsrc * sizeof(struct in6_addr)));
 2716         if (retval)
 2717                 return (retval);
 2718 
 2719         IN6_MULTI_LOCK();
 2720 
 2721         IF_ADDR_RLOCK(ifp);
 2722         TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
 2723                 if (ifma->ifma_addr->sa_family != AF_INET6 ||
 2724                     ifma->ifma_protospec == NULL)
 2725                         continue;
 2726                 inm = (struct in6_multi *)ifma->ifma_protospec;
 2727                 if (!IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, &mcaddr))
 2728                         continue;
 2729                 fmode = inm->in6m_st[1].iss_fmode;
 2730                 retval = SYSCTL_OUT(req, &fmode, sizeof(uint32_t));
 2731                 if (retval != 0)
 2732                         break;
 2733                 RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
 2734                         CTR2(KTR_MLD, "%s: visit node %p", __func__, ims);
 2735                         /*
 2736                          * Only copy-out sources which are in-mode.
 2737                          */
 2738                         if (fmode != im6s_get_mode(inm, ims, 1)) {
 2739                                 CTR1(KTR_MLD, "%s: skip non-in-mode",
 2740                                     __func__);
 2741                                 continue;
 2742                         }
 2743                         src = ims->im6s_addr;
 2744                         retval = SYSCTL_OUT(req, &src,
 2745                             sizeof(struct in6_addr));
 2746                         if (retval != 0)
 2747                                 break;
 2748                 }
 2749         }
 2750         IF_ADDR_RUNLOCK(ifp);
 2751 
 2752         IN6_MULTI_UNLOCK();
 2753 
 2754         return (retval);
 2755 }
 2756 
 2757 #ifdef KTR
 2758 
 2759 static const char *in6m_modestrs[] = { "un", "in", "ex" };
 2760 
 2761 static const char *
 2762 in6m_mode_str(const int mode)
 2763 {
 2764 
 2765         if (mode >= MCAST_UNDEFINED && mode <= MCAST_EXCLUDE)
 2766                 return (in6m_modestrs[mode]);
 2767         return ("??");
 2768 }
 2769 
 2770 static const char *in6m_statestrs[] = {
 2771         "not-member",
 2772         "silent",
 2773         "idle",
 2774         "lazy",
 2775         "sleeping",
 2776         "awakening",
 2777         "query-pending",
 2778         "sg-query-pending",
 2779         "leaving"
 2780 };
 2781 
 2782 static const char *
 2783 in6m_state_str(const int state)
 2784 {
 2785 
 2786         if (state >= MLD_NOT_MEMBER && state <= MLD_LEAVING_MEMBER)
 2787                 return (in6m_statestrs[state]);
 2788         return ("??");
 2789 }
 2790 
 2791 /*
 2792  * Dump an in6_multi structure to the console.
 2793  */
 2794 void
 2795 in6m_print(const struct in6_multi *inm)
 2796 {
 2797         int t;
 2798         char ip6tbuf[INET6_ADDRSTRLEN];
 2799 
 2800         if ((ktr_mask & KTR_MLD) == 0)
 2801                 return;
 2802 
 2803         printf("%s: --- begin in6m %p ---\n", __func__, inm);
 2804         printf("addr %s ifp %p(%s) ifma %p\n",
 2805             ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2806             inm->in6m_ifp,
 2807             inm->in6m_ifp->if_xname,
 2808             inm->in6m_ifma);
 2809         printf("timer %u state %s refcount %u scq.len %u\n",
 2810             inm->in6m_timer,
 2811             in6m_state_str(inm->in6m_state),
 2812             inm->in6m_refcount,
 2813             inm->in6m_scq.ifq_len);
 2814         printf("mli %p nsrc %lu sctimer %u scrv %u\n",
 2815             inm->in6m_mli,
 2816             inm->in6m_nsrc,
 2817             inm->in6m_sctimer,
 2818             inm->in6m_scrv);
 2819         for (t = 0; t < 2; t++) {
 2820                 printf("t%d: fmode %s asm %u ex %u in %u rec %u\n", t,
 2821                     in6m_mode_str(inm->in6m_st[t].iss_fmode),
 2822                     inm->in6m_st[t].iss_asm,
 2823                     inm->in6m_st[t].iss_ex,
 2824                     inm->in6m_st[t].iss_in,
 2825                     inm->in6m_st[t].iss_rec);
 2826         }
 2827         printf("%s: --- end in6m %p ---\n", __func__, inm);
 2828 }
 2829 
 2830 #else /* !KTR */
 2831 
 2832 void
 2833 in6m_print(const struct in6_multi *inm)
 2834 {
 2835 
 2836 }
 2837 
 2838 #endif /* KTR */

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