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


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

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    1 /*
    2  * Copyright (c) 2009 Bruce Simpson.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. The name of the author may not be used to endorse or promote
   14  *    products derived from this software without specific prior written
   15  *    permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 /*
   31  * IPv6 multicast socket, group, and socket option processing module.
   32  * Normative references: RFC 2292, RFC 3492, RFC 3542, RFC 3678, RFC 3810.
   33  */
   34 
   35 #include <sys/cdefs.h>
   36 __FBSDID("$FreeBSD$");
   37 
   38 #include "opt_inet6.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/kernel.h>
   43 #include <sys/malloc.h>
   44 #include <sys/mbuf.h>
   45 #include <sys/protosw.h>
   46 #include <sys/socket.h>
   47 #include <sys/socketvar.h>
   48 #include <sys/protosw.h>
   49 #include <sys/sysctl.h>
   50 #include <sys/priv.h>
   51 #include <sys/ktr.h>
   52 #include <sys/tree.h>
   53 
   54 #include <net/if.h>
   55 #include <net/if_var.h>
   56 #include <net/if_dl.h>
   57 #include <net/route.h>
   58 #include <net/vnet.h>
   59 
   60 #include <netinet/in.h>
   61 #include <netinet/in_var.h>
   62 #include <netinet6/in6_fib.h>
   63 #include <netinet6/in6_var.h>
   64 #include <netinet/ip6.h>
   65 #include <netinet/icmp6.h>
   66 #include <netinet6/ip6_var.h>
   67 #include <netinet/in_pcb.h>
   68 #include <netinet/tcp_var.h>
   69 #include <netinet6/nd6.h>
   70 #include <netinet6/mld6_var.h>
   71 #include <netinet6/scope6_var.h>
   72 
   73 #ifndef KTR_MLD
   74 #define KTR_MLD KTR_INET6
   75 #endif
   76 
   77 #ifndef __SOCKUNION_DECLARED
   78 union sockunion {
   79         struct sockaddr_storage ss;
   80         struct sockaddr         sa;
   81         struct sockaddr_dl      sdl;
   82         struct sockaddr_in6     sin6;
   83 };
   84 typedef union sockunion sockunion_t;
   85 #define __SOCKUNION_DECLARED
   86 #endif /* __SOCKUNION_DECLARED */
   87 
   88 static MALLOC_DEFINE(M_IN6MFILTER, "in6_mfilter",
   89     "IPv6 multicast PCB-layer source filter");
   90 static MALLOC_DEFINE(M_IP6MADDR, "in6_multi", "IPv6 multicast group");
   91 static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "IPv6 multicast options");
   92 static MALLOC_DEFINE(M_IP6MSOURCE, "ip6_msource",
   93     "IPv6 multicast MLD-layer source filter");
   94 
   95 RB_GENERATE(ip6_msource_tree, ip6_msource, im6s_link, ip6_msource_cmp);
   96 
   97 /*
   98  * Locking:
   99  * - Lock order is: Giant, INP_WLOCK, IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
  100  * - The IF_ADDR_LOCK is implicitly taken by in6m_lookup() earlier, however
  101  *   it can be taken by code in net/if.c also.
  102  * - ip6_moptions and in6_mfilter are covered by the INP_WLOCK.
  103  *
  104  * struct in6_multi is covered by IN6_MULTI_LOCK. There isn't strictly
  105  * any need for in6_multi itself to be virtualized -- it is bound to an ifp
  106  * anyway no matter what happens.
  107  */
  108 struct mtx in6_multi_mtx;
  109 MTX_SYSINIT(in6_multi_mtx, &in6_multi_mtx, "in6_multi_mtx", MTX_DEF);
  110 
  111 static void     im6f_commit(struct in6_mfilter *);
  112 static int      im6f_get_source(struct in6_mfilter *imf,
  113                     const struct sockaddr_in6 *psin,
  114                     struct in6_msource **);
  115 static struct in6_msource *
  116                 im6f_graft(struct in6_mfilter *, const uint8_t,
  117                     const struct sockaddr_in6 *);
  118 static void     im6f_leave(struct in6_mfilter *);
  119 static int      im6f_prune(struct in6_mfilter *, const struct sockaddr_in6 *);
  120 static void     im6f_purge(struct in6_mfilter *);
  121 static void     im6f_rollback(struct in6_mfilter *);
  122 static void     im6f_reap(struct in6_mfilter *);
  123 static int      im6o_grow(struct ip6_moptions *);
  124 static size_t   im6o_match_group(const struct ip6_moptions *,
  125                     const struct ifnet *, const struct sockaddr *);
  126 static struct in6_msource *
  127                 im6o_match_source(const struct ip6_moptions *, const size_t,
  128                     const struct sockaddr *);
  129 static void     im6s_merge(struct ip6_msource *ims,
  130                     const struct in6_msource *lims, const int rollback);
  131 static int      in6_mc_get(struct ifnet *, const struct in6_addr *,
  132                     struct in6_multi **);
  133 static int      in6m_get_source(struct in6_multi *inm,
  134                     const struct in6_addr *addr, const int noalloc,
  135                     struct ip6_msource **pims);
  136 #ifdef KTR
  137 static int      in6m_is_ifp_detached(const struct in6_multi *);
  138 #endif
  139 static int      in6m_merge(struct in6_multi *, /*const*/ struct in6_mfilter *);
  140 static void     in6m_purge(struct in6_multi *);
  141 static void     in6m_reap(struct in6_multi *);
  142 static struct ip6_moptions *
  143                 in6p_findmoptions(struct inpcb *);
  144 static int      in6p_get_source_filters(struct inpcb *, struct sockopt *);
  145 static int      in6p_join_group(struct inpcb *, struct sockopt *);
  146 static int      in6p_leave_group(struct inpcb *, struct sockopt *);
  147 static struct ifnet *
  148                 in6p_lookup_mcast_ifp(const struct inpcb *,
  149                     const struct sockaddr_in6 *);
  150 static int      in6p_block_unblock_source(struct inpcb *, struct sockopt *);
  151 static int      in6p_set_multicast_if(struct inpcb *, struct sockopt *);
  152 static int      in6p_set_source_filters(struct inpcb *, struct sockopt *);
  153 static int      sysctl_ip6_mcast_filters(SYSCTL_HANDLER_ARGS);
  154 
  155 SYSCTL_DECL(_net_inet6_ip6);    /* XXX Not in any common header. */
  156 
  157 static SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, mcast, CTLFLAG_RW, 0,
  158     "IPv6 multicast");
  159 
  160 static u_long in6_mcast_maxgrpsrc = IPV6_MAX_GROUP_SRC_FILTER;
  161 SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxgrpsrc,
  162     CTLFLAG_RWTUN, &in6_mcast_maxgrpsrc, 0,
  163     "Max source filters per group");
  164 
  165 static u_long in6_mcast_maxsocksrc = IPV6_MAX_SOCK_SRC_FILTER;
  166 SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxsocksrc,
  167     CTLFLAG_RWTUN, &in6_mcast_maxsocksrc, 0,
  168     "Max source filters per socket");
  169 
  170 /* TODO Virtualize this switch. */
  171 int in6_mcast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
  172 SYSCTL_INT(_net_inet6_ip6_mcast, OID_AUTO, loop, CTLFLAG_RWTUN,
  173     &in6_mcast_loop, 0, "Loopback multicast datagrams by default");
  174 
  175 static SYSCTL_NODE(_net_inet6_ip6_mcast, OID_AUTO, filters,
  176     CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_ip6_mcast_filters,
  177     "Per-interface stack-wide source filters");
  178 
  179 #ifdef KTR
  180 /*
  181  * Inline function which wraps assertions for a valid ifp.
  182  * The ifnet layer will set the ifma's ifp pointer to NULL if the ifp
  183  * is detached.
  184  */
  185 static int __inline
  186 in6m_is_ifp_detached(const struct in6_multi *inm)
  187 {
  188         struct ifnet *ifp;
  189 
  190         KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
  191         ifp = inm->in6m_ifma->ifma_ifp;
  192         if (ifp != NULL) {
  193                 /*
  194                  * Sanity check that network-layer notion of ifp is the
  195                  * same as that of link-layer.
  196                  */
  197                 KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
  198         }
  199 
  200         return (ifp == NULL);
  201 }
  202 #endif
  203 
  204 /*
  205  * Initialize an in6_mfilter structure to a known state at t0, t1
  206  * with an empty source filter list.
  207  */
  208 static __inline void
  209 im6f_init(struct in6_mfilter *imf, const int st0, const int st1)
  210 {
  211         memset(imf, 0, sizeof(struct in6_mfilter));
  212         RB_INIT(&imf->im6f_sources);
  213         imf->im6f_st[0] = st0;
  214         imf->im6f_st[1] = st1;
  215 }
  216 
  217 /*
  218  * Resize the ip6_moptions vector to the next power-of-two minus 1.
  219  * May be called with locks held; do not sleep.
  220  */
  221 static int
  222 im6o_grow(struct ip6_moptions *imo)
  223 {
  224         struct in6_multi        **nmships;
  225         struct in6_multi        **omships;
  226         struct in6_mfilter       *nmfilters;
  227         struct in6_mfilter       *omfilters;
  228         size_t                    idx;
  229         size_t                    newmax;
  230         size_t                    oldmax;
  231 
  232         nmships = NULL;
  233         nmfilters = NULL;
  234         omships = imo->im6o_membership;
  235         omfilters = imo->im6o_mfilters;
  236         oldmax = imo->im6o_max_memberships;
  237         newmax = ((oldmax + 1) * 2) - 1;
  238 
  239         if (newmax <= IPV6_MAX_MEMBERSHIPS) {
  240                 nmships = (struct in6_multi **)realloc(omships,
  241                     sizeof(struct in6_multi *) * newmax, M_IP6MOPTS, M_NOWAIT);
  242                 nmfilters = (struct in6_mfilter *)realloc(omfilters,
  243                     sizeof(struct in6_mfilter) * newmax, M_IN6MFILTER,
  244                     M_NOWAIT);
  245                 if (nmships != NULL && nmfilters != NULL) {
  246                         /* Initialize newly allocated source filter heads. */
  247                         for (idx = oldmax; idx < newmax; idx++) {
  248                                 im6f_init(&nmfilters[idx], MCAST_UNDEFINED,
  249                                     MCAST_EXCLUDE);
  250                         }
  251                         imo->im6o_max_memberships = newmax;
  252                         imo->im6o_membership = nmships;
  253                         imo->im6o_mfilters = nmfilters;
  254                 }
  255         }
  256 
  257         if (nmships == NULL || nmfilters == NULL) {
  258                 if (nmships != NULL)
  259                         free(nmships, M_IP6MOPTS);
  260                 if (nmfilters != NULL)
  261                         free(nmfilters, M_IN6MFILTER);
  262                 return (ETOOMANYREFS);
  263         }
  264 
  265         return (0);
  266 }
  267 
  268 /*
  269  * Find an IPv6 multicast group entry for this ip6_moptions instance
  270  * which matches the specified group, and optionally an interface.
  271  * Return its index into the array, or -1 if not found.
  272  */
  273 static size_t
  274 im6o_match_group(const struct ip6_moptions *imo, const struct ifnet *ifp,
  275     const struct sockaddr *group)
  276 {
  277         const struct sockaddr_in6 *gsin6;
  278         struct in6_multi        **pinm;
  279         int               idx;
  280         int               nmships;
  281 
  282         gsin6 = (const struct sockaddr_in6 *)group;
  283 
  284         /* The im6o_membership array may be lazy allocated. */
  285         if (imo->im6o_membership == NULL || imo->im6o_num_memberships == 0)
  286                 return (-1);
  287 
  288         nmships = imo->im6o_num_memberships;
  289         pinm = &imo->im6o_membership[0];
  290         for (idx = 0; idx < nmships; idx++, pinm++) {
  291                 if (*pinm == NULL)
  292                         continue;
  293                 if ((ifp == NULL || ((*pinm)->in6m_ifp == ifp)) &&
  294                     IN6_ARE_ADDR_EQUAL(&(*pinm)->in6m_addr,
  295                     &gsin6->sin6_addr)) {
  296                         break;
  297                 }
  298         }
  299         if (idx >= nmships)
  300                 idx = -1;
  301 
  302         return (idx);
  303 }
  304 
  305 /*
  306  * Find an IPv6 multicast source entry for this imo which matches
  307  * the given group index for this socket, and source address.
  308  *
  309  * XXX TODO: The scope ID, if present in src, is stripped before
  310  * any comparison. We SHOULD enforce scope/zone checks where the source
  311  * filter entry has a link scope.
  312  *
  313  * NOTE: This does not check if the entry is in-mode, merely if
  314  * it exists, which may not be the desired behaviour.
  315  */
  316 static struct in6_msource *
  317 im6o_match_source(const struct ip6_moptions *imo, const size_t gidx,
  318     const struct sockaddr *src)
  319 {
  320         struct ip6_msource       find;
  321         struct in6_mfilter      *imf;
  322         struct ip6_msource      *ims;
  323         const sockunion_t       *psa;
  324 
  325         KASSERT(src->sa_family == AF_INET6, ("%s: !AF_INET6", __func__));
  326         KASSERT(gidx != -1 && gidx < imo->im6o_num_memberships,
  327             ("%s: invalid index %d\n", __func__, (int)gidx));
  328 
  329         /* The im6o_mfilters array may be lazy allocated. */
  330         if (imo->im6o_mfilters == NULL)
  331                 return (NULL);
  332         imf = &imo->im6o_mfilters[gidx];
  333 
  334         psa = (const sockunion_t *)src;
  335         find.im6s_addr = psa->sin6.sin6_addr;
  336         in6_clearscope(&find.im6s_addr);                /* XXX */
  337         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  338 
  339         return ((struct in6_msource *)ims);
  340 }
  341 
  342 /*
  343  * Perform filtering for multicast datagrams on a socket by group and source.
  344  *
  345  * Returns 0 if a datagram should be allowed through, or various error codes
  346  * if the socket was not a member of the group, or the source was muted, etc.
  347  */
  348 int
  349 im6o_mc_filter(const struct ip6_moptions *imo, const struct ifnet *ifp,
  350     const struct sockaddr *group, const struct sockaddr *src)
  351 {
  352         size_t gidx;
  353         struct in6_msource *ims;
  354         int mode;
  355 
  356         KASSERT(ifp != NULL, ("%s: null ifp", __func__));
  357 
  358         gidx = im6o_match_group(imo, ifp, group);
  359         if (gidx == -1)
  360                 return (MCAST_NOTGMEMBER);
  361 
  362         /*
  363          * Check if the source was included in an (S,G) join.
  364          * Allow reception on exclusive memberships by default,
  365          * reject reception on inclusive memberships by default.
  366          * Exclude source only if an in-mode exclude filter exists.
  367          * Include source only if an in-mode include filter exists.
  368          * NOTE: We are comparing group state here at MLD t1 (now)
  369          * with socket-layer t0 (since last downcall).
  370          */
  371         mode = imo->im6o_mfilters[gidx].im6f_st[1];
  372         ims = im6o_match_source(imo, gidx, src);
  373 
  374         if ((ims == NULL && mode == MCAST_INCLUDE) ||
  375             (ims != NULL && ims->im6sl_st[0] != mode))
  376                 return (MCAST_NOTSMEMBER);
  377 
  378         return (MCAST_PASS);
  379 }
  380 
  381 /*
  382  * Find and return a reference to an in6_multi record for (ifp, group),
  383  * and bump its reference count.
  384  * If one does not exist, try to allocate it, and update link-layer multicast
  385  * filters on ifp to listen for group.
  386  * Assumes the IN6_MULTI lock is held across the call.
  387  * Return 0 if successful, otherwise return an appropriate error code.
  388  */
  389 static int
  390 in6_mc_get(struct ifnet *ifp, const struct in6_addr *group,
  391     struct in6_multi **pinm)
  392 {
  393         struct sockaddr_in6      gsin6;
  394         struct ifmultiaddr      *ifma;
  395         struct in6_multi        *inm;
  396         int                      error;
  397 
  398         error = 0;
  399 
  400         /*
  401          * XXX: Accesses to ifma_protospec must be covered by IF_ADDR_LOCK;
  402          * if_addmulti() takes this mutex itself, so we must drop and
  403          * re-acquire around the call.
  404          */
  405         IN6_MULTI_LOCK_ASSERT();
  406         IF_ADDR_WLOCK(ifp);
  407 
  408         inm = in6m_lookup_locked(ifp, group);
  409         if (inm != NULL) {
  410                 /*
  411                  * If we already joined this group, just bump the
  412                  * refcount and return it.
  413                  */
  414                 KASSERT(inm->in6m_refcount >= 1,
  415                     ("%s: bad refcount %d", __func__, inm->in6m_refcount));
  416                 ++inm->in6m_refcount;
  417                 *pinm = inm;
  418                 goto out_locked;
  419         }
  420 
  421         memset(&gsin6, 0, sizeof(gsin6));
  422         gsin6.sin6_family = AF_INET6;
  423         gsin6.sin6_len = sizeof(struct sockaddr_in6);
  424         gsin6.sin6_addr = *group;
  425 
  426         /*
  427          * Check if a link-layer group is already associated
  428          * with this network-layer group on the given ifnet.
  429          */
  430         IF_ADDR_WUNLOCK(ifp);
  431         error = if_addmulti(ifp, (struct sockaddr *)&gsin6, &ifma);
  432         if (error != 0)
  433                 return (error);
  434         IF_ADDR_WLOCK(ifp);
  435 
  436         /*
  437          * If something other than netinet6 is occupying the link-layer
  438          * group, print a meaningful error message and back out of
  439          * the allocation.
  440          * Otherwise, bump the refcount on the existing network-layer
  441          * group association and return it.
  442          */
  443         if (ifma->ifma_protospec != NULL) {
  444                 inm = (struct in6_multi *)ifma->ifma_protospec;
  445 #ifdef INVARIANTS
  446                 KASSERT(ifma->ifma_addr != NULL, ("%s: no ifma_addr",
  447                     __func__));
  448                 KASSERT(ifma->ifma_addr->sa_family == AF_INET6,
  449                     ("%s: ifma not AF_INET6", __func__));
  450                 KASSERT(inm != NULL, ("%s: no ifma_protospec", __func__));
  451                 if (inm->in6m_ifma != ifma || inm->in6m_ifp != ifp ||
  452                     !IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, group))
  453                         panic("%s: ifma %p is inconsistent with %p (%p)",
  454                             __func__, ifma, inm, group);
  455 #endif
  456                 ++inm->in6m_refcount;
  457                 *pinm = inm;
  458                 goto out_locked;
  459         }
  460 
  461         IF_ADDR_WLOCK_ASSERT(ifp);
  462 
  463         /*
  464          * A new in6_multi record is needed; allocate and initialize it.
  465          * We DO NOT perform an MLD join as the in6_ layer may need to
  466          * push an initial source list down to MLD to support SSM.
  467          *
  468          * The initial source filter state is INCLUDE, {} as per the RFC.
  469          * Pending state-changes per group are subject to a bounds check.
  470          */
  471         inm = malloc(sizeof(*inm), M_IP6MADDR, M_NOWAIT | M_ZERO);
  472         if (inm == NULL) {
  473                 IF_ADDR_WUNLOCK(ifp);
  474                 if_delmulti_ifma(ifma);
  475                 return (ENOMEM);
  476         }
  477         inm->in6m_addr = *group;
  478         inm->in6m_ifp = ifp;
  479         inm->in6m_mli = MLD_IFINFO(ifp);
  480         inm->in6m_ifma = ifma;
  481         inm->in6m_refcount = 1;
  482         inm->in6m_state = MLD_NOT_MEMBER;
  483         mbufq_init(&inm->in6m_scq, MLD_MAX_STATE_CHANGES);
  484 
  485         inm->in6m_st[0].iss_fmode = MCAST_UNDEFINED;
  486         inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
  487         RB_INIT(&inm->in6m_srcs);
  488 
  489         ifma->ifma_protospec = inm;
  490         *pinm = inm;
  491 
  492 out_locked:
  493         IF_ADDR_WUNLOCK(ifp);
  494         return (error);
  495 }
  496 
  497 /*
  498  * Drop a reference to an in6_multi record.
  499  *
  500  * If the refcount drops to 0, free the in6_multi record and
  501  * delete the underlying link-layer membership.
  502  */
  503 void
  504 in6m_release_locked(struct in6_multi *inm)
  505 {
  506         struct ifmultiaddr *ifma;
  507 
  508         IN6_MULTI_LOCK_ASSERT();
  509 
  510         CTR2(KTR_MLD, "%s: refcount is %d", __func__, inm->in6m_refcount);
  511 
  512         if (--inm->in6m_refcount > 0) {
  513                 CTR2(KTR_MLD, "%s: refcount is now %d", __func__,
  514                     inm->in6m_refcount);
  515                 return;
  516         }
  517 
  518         CTR2(KTR_MLD, "%s: freeing inm %p", __func__, inm);
  519 
  520         ifma = inm->in6m_ifma;
  521 
  522         /* XXX this access is not covered by IF_ADDR_LOCK */
  523         CTR2(KTR_MLD, "%s: purging ifma %p", __func__, ifma);
  524         KASSERT(ifma->ifma_protospec == inm,
  525             ("%s: ifma_protospec != inm", __func__));
  526         ifma->ifma_protospec = NULL;
  527 
  528         in6m_purge(inm);
  529 
  530         free(inm, M_IP6MADDR);
  531 
  532         if_delmulti_ifma(ifma);
  533 }
  534 
  535 /*
  536  * Clear recorded source entries for a group.
  537  * Used by the MLD code. Caller must hold the IN6_MULTI lock.
  538  * FIXME: Should reap.
  539  */
  540 void
  541 in6m_clear_recorded(struct in6_multi *inm)
  542 {
  543         struct ip6_msource      *ims;
  544 
  545         IN6_MULTI_LOCK_ASSERT();
  546 
  547         RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
  548                 if (ims->im6s_stp) {
  549                         ims->im6s_stp = 0;
  550                         --inm->in6m_st[1].iss_rec;
  551                 }
  552         }
  553         KASSERT(inm->in6m_st[1].iss_rec == 0,
  554             ("%s: iss_rec %d not 0", __func__, inm->in6m_st[1].iss_rec));
  555 }
  556 
  557 /*
  558  * Record a source as pending for a Source-Group MLDv2 query.
  559  * This lives here as it modifies the shared tree.
  560  *
  561  * inm is the group descriptor.
  562  * naddr is the address of the source to record in network-byte order.
  563  *
  564  * If the net.inet6.mld.sgalloc sysctl is non-zero, we will
  565  * lazy-allocate a source node in response to an SG query.
  566  * Otherwise, no allocation is performed. This saves some memory
  567  * with the trade-off that the source will not be reported to the
  568  * router if joined in the window between the query response and
  569  * the group actually being joined on the local host.
  570  *
  571  * VIMAGE: XXX: Currently the mld_sgalloc feature has been removed.
  572  * This turns off the allocation of a recorded source entry if
  573  * the group has not been joined.
  574  *
  575  * Return 0 if the source didn't exist or was already marked as recorded.
  576  * Return 1 if the source was marked as recorded by this function.
  577  * Return <0 if any error occurred (negated errno code).
  578  */
  579 int
  580 in6m_record_source(struct in6_multi *inm, const struct in6_addr *addr)
  581 {
  582         struct ip6_msource       find;
  583         struct ip6_msource      *ims, *nims;
  584 
  585         IN6_MULTI_LOCK_ASSERT();
  586 
  587         find.im6s_addr = *addr;
  588         ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
  589         if (ims && ims->im6s_stp)
  590                 return (0);
  591         if (ims == NULL) {
  592                 if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
  593                         return (-ENOSPC);
  594                 nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
  595                     M_NOWAIT | M_ZERO);
  596                 if (nims == NULL)
  597                         return (-ENOMEM);
  598                 nims->im6s_addr = find.im6s_addr;
  599                 RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
  600                 ++inm->in6m_nsrc;
  601                 ims = nims;
  602         }
  603 
  604         /*
  605          * Mark the source as recorded and update the recorded
  606          * source count.
  607          */
  608         ++ims->im6s_stp;
  609         ++inm->in6m_st[1].iss_rec;
  610 
  611         return (1);
  612 }
  613 
  614 /*
  615  * Return a pointer to an in6_msource owned by an in6_mfilter,
  616  * given its source address.
  617  * Lazy-allocate if needed. If this is a new entry its filter state is
  618  * undefined at t0.
  619  *
  620  * imf is the filter set being modified.
  621  * addr is the source address.
  622  *
  623  * SMPng: May be called with locks held; malloc must not block.
  624  */
  625 static int
  626 im6f_get_source(struct in6_mfilter *imf, const struct sockaddr_in6 *psin,
  627     struct in6_msource **plims)
  628 {
  629         struct ip6_msource       find;
  630         struct ip6_msource      *ims, *nims;
  631         struct in6_msource      *lims;
  632         int                      error;
  633 
  634         error = 0;
  635         ims = NULL;
  636         lims = NULL;
  637 
  638         find.im6s_addr = psin->sin6_addr;
  639         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  640         lims = (struct in6_msource *)ims;
  641         if (lims == NULL) {
  642                 if (imf->im6f_nsrc == in6_mcast_maxsocksrc)
  643                         return (ENOSPC);
  644                 nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
  645                     M_NOWAIT | M_ZERO);
  646                 if (nims == NULL)
  647                         return (ENOMEM);
  648                 lims = (struct in6_msource *)nims;
  649                 lims->im6s_addr = find.im6s_addr;
  650                 lims->im6sl_st[0] = MCAST_UNDEFINED;
  651                 RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
  652                 ++imf->im6f_nsrc;
  653         }
  654 
  655         *plims = lims;
  656 
  657         return (error);
  658 }
  659 
  660 /*
  661  * Graft a source entry into an existing socket-layer filter set,
  662  * maintaining any required invariants and checking allocations.
  663  *
  664  * The source is marked as being in the new filter mode at t1.
  665  *
  666  * Return the pointer to the new node, otherwise return NULL.
  667  */
  668 static struct in6_msource *
  669 im6f_graft(struct in6_mfilter *imf, const uint8_t st1,
  670     const struct sockaddr_in6 *psin)
  671 {
  672         struct ip6_msource      *nims;
  673         struct in6_msource      *lims;
  674 
  675         nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
  676             M_NOWAIT | M_ZERO);
  677         if (nims == NULL)
  678                 return (NULL);
  679         lims = (struct in6_msource *)nims;
  680         lims->im6s_addr = psin->sin6_addr;
  681         lims->im6sl_st[0] = MCAST_UNDEFINED;
  682         lims->im6sl_st[1] = st1;
  683         RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
  684         ++imf->im6f_nsrc;
  685 
  686         return (lims);
  687 }
  688 
  689 /*
  690  * Prune a source entry from an existing socket-layer filter set,
  691  * maintaining any required invariants and checking allocations.
  692  *
  693  * The source is marked as being left at t1, it is not freed.
  694  *
  695  * Return 0 if no error occurred, otherwise return an errno value.
  696  */
  697 static int
  698 im6f_prune(struct in6_mfilter *imf, const struct sockaddr_in6 *psin)
  699 {
  700         struct ip6_msource       find;
  701         struct ip6_msource      *ims;
  702         struct in6_msource      *lims;
  703 
  704         find.im6s_addr = psin->sin6_addr;
  705         ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
  706         if (ims == NULL)
  707                 return (ENOENT);
  708         lims = (struct in6_msource *)ims;
  709         lims->im6sl_st[1] = MCAST_UNDEFINED;
  710         return (0);
  711 }
  712 
  713 /*
  714  * Revert socket-layer filter set deltas at t1 to t0 state.
  715  */
  716 static void
  717 im6f_rollback(struct in6_mfilter *imf)
  718 {
  719         struct ip6_msource      *ims, *tims;
  720         struct in6_msource      *lims;
  721 
  722         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  723                 lims = (struct in6_msource *)ims;
  724                 if (lims->im6sl_st[0] == lims->im6sl_st[1]) {
  725                         /* no change at t1 */
  726                         continue;
  727                 } else if (lims->im6sl_st[0] != MCAST_UNDEFINED) {
  728                         /* revert change to existing source at t1 */
  729                         lims->im6sl_st[1] = lims->im6sl_st[0];
  730                 } else {
  731                         /* revert source added t1 */
  732                         CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
  733                         RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  734                         free(ims, M_IN6MFILTER);
  735                         imf->im6f_nsrc--;
  736                 }
  737         }
  738         imf->im6f_st[1] = imf->im6f_st[0];
  739 }
  740 
  741 /*
  742  * Mark socket-layer filter set as INCLUDE {} at t1.
  743  */
  744 static void
  745 im6f_leave(struct in6_mfilter *imf)
  746 {
  747         struct ip6_msource      *ims;
  748         struct in6_msource      *lims;
  749 
  750         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  751                 lims = (struct in6_msource *)ims;
  752                 lims->im6sl_st[1] = MCAST_UNDEFINED;
  753         }
  754         imf->im6f_st[1] = MCAST_INCLUDE;
  755 }
  756 
  757 /*
  758  * Mark socket-layer filter set deltas as committed.
  759  */
  760 static void
  761 im6f_commit(struct in6_mfilter *imf)
  762 {
  763         struct ip6_msource      *ims;
  764         struct in6_msource      *lims;
  765 
  766         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  767                 lims = (struct in6_msource *)ims;
  768                 lims->im6sl_st[0] = lims->im6sl_st[1];
  769         }
  770         imf->im6f_st[0] = imf->im6f_st[1];
  771 }
  772 
  773 /*
  774  * Reap unreferenced sources from socket-layer filter set.
  775  */
  776 static void
  777 im6f_reap(struct in6_mfilter *imf)
  778 {
  779         struct ip6_msource      *ims, *tims;
  780         struct in6_msource      *lims;
  781 
  782         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  783                 lims = (struct in6_msource *)ims;
  784                 if ((lims->im6sl_st[0] == MCAST_UNDEFINED) &&
  785                     (lims->im6sl_st[1] == MCAST_UNDEFINED)) {
  786                         CTR2(KTR_MLD, "%s: free lims %p", __func__, ims);
  787                         RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  788                         free(ims, M_IN6MFILTER);
  789                         imf->im6f_nsrc--;
  790                 }
  791         }
  792 }
  793 
  794 /*
  795  * Purge socket-layer filter set.
  796  */
  797 static void
  798 im6f_purge(struct in6_mfilter *imf)
  799 {
  800         struct ip6_msource      *ims, *tims;
  801 
  802         RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
  803                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
  804                 RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
  805                 free(ims, M_IN6MFILTER);
  806                 imf->im6f_nsrc--;
  807         }
  808         imf->im6f_st[0] = imf->im6f_st[1] = MCAST_UNDEFINED;
  809         KASSERT(RB_EMPTY(&imf->im6f_sources),
  810             ("%s: im6f_sources not empty", __func__));
  811 }
  812 
  813 /*
  814  * Look up a source filter entry for a multicast group.
  815  *
  816  * inm is the group descriptor to work with.
  817  * addr is the IPv6 address to look up.
  818  * noalloc may be non-zero to suppress allocation of sources.
  819  * *pims will be set to the address of the retrieved or allocated source.
  820  *
  821  * SMPng: NOTE: may be called with locks held.
  822  * Return 0 if successful, otherwise return a non-zero error code.
  823  */
  824 static int
  825 in6m_get_source(struct in6_multi *inm, const struct in6_addr *addr,
  826     const int noalloc, struct ip6_msource **pims)
  827 {
  828         struct ip6_msource       find;
  829         struct ip6_msource      *ims, *nims;
  830 #ifdef KTR
  831         char                     ip6tbuf[INET6_ADDRSTRLEN];
  832 #endif
  833 
  834         find.im6s_addr = *addr;
  835         ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
  836         if (ims == NULL && !noalloc) {
  837                 if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
  838                         return (ENOSPC);
  839                 nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
  840                     M_NOWAIT | M_ZERO);
  841                 if (nims == NULL)
  842                         return (ENOMEM);
  843                 nims->im6s_addr = *addr;
  844                 RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
  845                 ++inm->in6m_nsrc;
  846                 ims = nims;
  847                 CTR3(KTR_MLD, "%s: allocated %s as %p", __func__,
  848                     ip6_sprintf(ip6tbuf, addr), ims);
  849         }
  850 
  851         *pims = ims;
  852         return (0);
  853 }
  854 
  855 /*
  856  * Merge socket-layer source into MLD-layer source.
  857  * If rollback is non-zero, perform the inverse of the merge.
  858  */
  859 static void
  860 im6s_merge(struct ip6_msource *ims, const struct in6_msource *lims,
  861     const int rollback)
  862 {
  863         int n = rollback ? -1 : 1;
  864 #ifdef KTR
  865         char ip6tbuf[INET6_ADDRSTRLEN];
  866 
  867         ip6_sprintf(ip6tbuf, &lims->im6s_addr);
  868 #endif
  869 
  870         if (lims->im6sl_st[0] == MCAST_EXCLUDE) {
  871                 CTR3(KTR_MLD, "%s: t1 ex -= %d on %s", __func__, n, ip6tbuf);
  872                 ims->im6s_st[1].ex -= n;
  873         } else if (lims->im6sl_st[0] == MCAST_INCLUDE) {
  874                 CTR3(KTR_MLD, "%s: t1 in -= %d on %s", __func__, n, ip6tbuf);
  875                 ims->im6s_st[1].in -= n;
  876         }
  877 
  878         if (lims->im6sl_st[1] == MCAST_EXCLUDE) {
  879                 CTR3(KTR_MLD, "%s: t1 ex += %d on %s", __func__, n, ip6tbuf);
  880                 ims->im6s_st[1].ex += n;
  881         } else if (lims->im6sl_st[1] == MCAST_INCLUDE) {
  882                 CTR3(KTR_MLD, "%s: t1 in += %d on %s", __func__, n, ip6tbuf);
  883                 ims->im6s_st[1].in += n;
  884         }
  885 }
  886 
  887 /*
  888  * Atomically update the global in6_multi state, when a membership's
  889  * filter list is being updated in any way.
  890  *
  891  * imf is the per-inpcb-membership group filter pointer.
  892  * A fake imf may be passed for in-kernel consumers.
  893  *
  894  * XXX This is a candidate for a set-symmetric-difference style loop
  895  * which would eliminate the repeated lookup from root of ims nodes,
  896  * as they share the same key space.
  897  *
  898  * If any error occurred this function will back out of refcounts
  899  * and return a non-zero value.
  900  */
  901 static int
  902 in6m_merge(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
  903 {
  904         struct ip6_msource      *ims, *nims;
  905         struct in6_msource      *lims;
  906         int                      schanged, error;
  907         int                      nsrc0, nsrc1;
  908 
  909         schanged = 0;
  910         error = 0;
  911         nsrc1 = nsrc0 = 0;
  912 
  913         /*
  914          * Update the source filters first, as this may fail.
  915          * Maintain count of in-mode filters at t0, t1. These are
  916          * used to work out if we transition into ASM mode or not.
  917          * Maintain a count of source filters whose state was
  918          * actually modified by this operation.
  919          */
  920         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
  921                 lims = (struct in6_msource *)ims;
  922                 if (lims->im6sl_st[0] == imf->im6f_st[0]) nsrc0++;
  923                 if (lims->im6sl_st[1] == imf->im6f_st[1]) nsrc1++;
  924                 if (lims->im6sl_st[0] == lims->im6sl_st[1]) continue;
  925                 error = in6m_get_source(inm, &lims->im6s_addr, 0, &nims);
  926                 ++schanged;
  927                 if (error)
  928                         break;
  929                 im6s_merge(nims, lims, 0);
  930         }
  931         if (error) {
  932                 struct ip6_msource *bims;
  933 
  934                 RB_FOREACH_REVERSE_FROM(ims, ip6_msource_tree, nims) {
  935                         lims = (struct in6_msource *)ims;
  936                         if (lims->im6sl_st[0] == lims->im6sl_st[1])
  937                                 continue;
  938                         (void)in6m_get_source(inm, &lims->im6s_addr, 1, &bims);
  939                         if (bims == NULL)
  940                                 continue;
  941                         im6s_merge(bims, lims, 1);
  942                 }
  943                 goto out_reap;
  944         }
  945 
  946         CTR3(KTR_MLD, "%s: imf filters in-mode: %d at t0, %d at t1",
  947             __func__, nsrc0, nsrc1);
  948 
  949         /* Handle transition between INCLUDE {n} and INCLUDE {} on socket. */
  950         if (imf->im6f_st[0] == imf->im6f_st[1] &&
  951             imf->im6f_st[1] == MCAST_INCLUDE) {
  952                 if (nsrc1 == 0) {
  953                         CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
  954                         --inm->in6m_st[1].iss_in;
  955                 }
  956         }
  957 
  958         /* Handle filter mode transition on socket. */
  959         if (imf->im6f_st[0] != imf->im6f_st[1]) {
  960                 CTR3(KTR_MLD, "%s: imf transition %d to %d",
  961                     __func__, imf->im6f_st[0], imf->im6f_st[1]);
  962 
  963                 if (imf->im6f_st[0] == MCAST_EXCLUDE) {
  964                         CTR1(KTR_MLD, "%s: --ex on inm at t1", __func__);
  965                         --inm->in6m_st[1].iss_ex;
  966                 } else if (imf->im6f_st[0] == MCAST_INCLUDE) {
  967                         CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
  968                         --inm->in6m_st[1].iss_in;
  969                 }
  970 
  971                 if (imf->im6f_st[1] == MCAST_EXCLUDE) {
  972                         CTR1(KTR_MLD, "%s: ex++ on inm at t1", __func__);
  973                         inm->in6m_st[1].iss_ex++;
  974                 } else if (imf->im6f_st[1] == MCAST_INCLUDE && nsrc1 > 0) {
  975                         CTR1(KTR_MLD, "%s: in++ on inm at t1", __func__);
  976                         inm->in6m_st[1].iss_in++;
  977                 }
  978         }
  979 
  980         /*
  981          * Track inm filter state in terms of listener counts.
  982          * If there are any exclusive listeners, stack-wide
  983          * membership is exclusive.
  984          * Otherwise, if only inclusive listeners, stack-wide is inclusive.
  985          * If no listeners remain, state is undefined at t1,
  986          * and the MLD lifecycle for this group should finish.
  987          */
  988         if (inm->in6m_st[1].iss_ex > 0) {
  989                 CTR1(KTR_MLD, "%s: transition to EX", __func__);
  990                 inm->in6m_st[1].iss_fmode = MCAST_EXCLUDE;
  991         } else if (inm->in6m_st[1].iss_in > 0) {
  992                 CTR1(KTR_MLD, "%s: transition to IN", __func__);
  993                 inm->in6m_st[1].iss_fmode = MCAST_INCLUDE;
  994         } else {
  995                 CTR1(KTR_MLD, "%s: transition to UNDEF", __func__);
  996                 inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
  997         }
  998 
  999         /* Decrement ASM listener count on transition out of ASM mode. */
 1000         if (imf->im6f_st[0] == MCAST_EXCLUDE && nsrc0 == 0) {
 1001                 if ((imf->im6f_st[1] != MCAST_EXCLUDE) ||
 1002                     (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 > 0)) {
 1003                         CTR1(KTR_MLD, "%s: --asm on inm at t1", __func__);
 1004                         --inm->in6m_st[1].iss_asm;
 1005                 }
 1006         }
 1007 
 1008         /* Increment ASM listener count on transition to ASM mode. */
 1009         if (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 == 0) {
 1010                 CTR1(KTR_MLD, "%s: asm++ on inm at t1", __func__);
 1011                 inm->in6m_st[1].iss_asm++;
 1012         }
 1013 
 1014         CTR3(KTR_MLD, "%s: merged imf %p to inm %p", __func__, imf, inm);
 1015         in6m_print(inm);
 1016 
 1017 out_reap:
 1018         if (schanged > 0) {
 1019                 CTR1(KTR_MLD, "%s: sources changed; reaping", __func__);
 1020                 in6m_reap(inm);
 1021         }
 1022         return (error);
 1023 }
 1024 
 1025 /*
 1026  * Mark an in6_multi's filter set deltas as committed.
 1027  * Called by MLD after a state change has been enqueued.
 1028  */
 1029 void
 1030 in6m_commit(struct in6_multi *inm)
 1031 {
 1032         struct ip6_msource      *ims;
 1033 
 1034         CTR2(KTR_MLD, "%s: commit inm %p", __func__, inm);
 1035         CTR1(KTR_MLD, "%s: pre commit:", __func__);
 1036         in6m_print(inm);
 1037 
 1038         RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
 1039                 ims->im6s_st[0] = ims->im6s_st[1];
 1040         }
 1041         inm->in6m_st[0] = inm->in6m_st[1];
 1042 }
 1043 
 1044 /*
 1045  * Reap unreferenced nodes from an in6_multi's filter set.
 1046  */
 1047 static void
 1048 in6m_reap(struct in6_multi *inm)
 1049 {
 1050         struct ip6_msource      *ims, *tims;
 1051 
 1052         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1053                 if (ims->im6s_st[0].ex > 0 || ims->im6s_st[0].in > 0 ||
 1054                     ims->im6s_st[1].ex > 0 || ims->im6s_st[1].in > 0 ||
 1055                     ims->im6s_stp != 0)
 1056                         continue;
 1057                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1058                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1059                 free(ims, M_IP6MSOURCE);
 1060                 inm->in6m_nsrc--;
 1061         }
 1062 }
 1063 
 1064 /*
 1065  * Purge all source nodes from an in6_multi's filter set.
 1066  */
 1067 static void
 1068 in6m_purge(struct in6_multi *inm)
 1069 {
 1070         struct ip6_msource      *ims, *tims;
 1071 
 1072         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1073                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1074                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1075                 free(ims, M_IP6MSOURCE);
 1076                 inm->in6m_nsrc--;
 1077         }
 1078         /* Free state-change requests that might be queued. */
 1079         mbufq_drain(&inm->in6m_scq);
 1080 }
 1081 
 1082 /*
 1083  * Join a multicast address w/o sources.
 1084  * KAME compatibility entry point.
 1085  *
 1086  * SMPng: Assume no mc locks held by caller.
 1087  */
 1088 struct in6_multi_mship *
 1089 in6_joingroup(struct ifnet *ifp, struct in6_addr *mcaddr,
 1090     int *errorp, int delay)
 1091 {
 1092         struct in6_multi_mship *imm;
 1093         int error;
 1094 
 1095         imm = malloc(sizeof(*imm), M_IP6MADDR, M_NOWAIT);
 1096         if (imm == NULL) {
 1097                 *errorp = ENOBUFS;
 1098                 return (NULL);
 1099         }
 1100 
 1101         delay = (delay * PR_FASTHZ) / hz;
 1102 
 1103         error = in6_mc_join(ifp, mcaddr, NULL, &imm->i6mm_maddr, delay);
 1104         if (error) {
 1105                 *errorp = error;
 1106                 free(imm, M_IP6MADDR);
 1107                 return (NULL);
 1108         }
 1109 
 1110         return (imm);
 1111 }
 1112 
 1113 /*
 1114  * Leave a multicast address w/o sources.
 1115  * KAME compatibility entry point.
 1116  *
 1117  * SMPng: Assume no mc locks held by caller.
 1118  */
 1119 int
 1120 in6_leavegroup(struct in6_multi_mship *imm)
 1121 {
 1122 
 1123         if (imm->i6mm_maddr != NULL)
 1124                 in6_mc_leave(imm->i6mm_maddr, NULL);
 1125         free(imm,  M_IP6MADDR);
 1126         return 0;
 1127 }
 1128 
 1129 /*
 1130  * Join a multicast group; unlocked entry point.
 1131  *
 1132  * SMPng: XXX: in6_mc_join() is called from in6_control() when upper
 1133  * locks are not held. Fortunately, ifp is unlikely to have been detached
 1134  * at this point, so we assume it's OK to recurse.
 1135  */
 1136 int
 1137 in6_mc_join(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1138     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1139     const int delay)
 1140 {
 1141         int error;
 1142 
 1143         IN6_MULTI_LOCK();
 1144         error = in6_mc_join_locked(ifp, mcaddr, imf, pinm, delay);
 1145         IN6_MULTI_UNLOCK();
 1146 
 1147         return (error);
 1148 }
 1149 
 1150 /*
 1151  * Join a multicast group; real entry point.
 1152  *
 1153  * Only preserves atomicity at inm level.
 1154  * NOTE: imf argument cannot be const due to sys/tree.h limitations.
 1155  *
 1156  * If the MLD downcall fails, the group is not joined, and an error
 1157  * code is returned.
 1158  */
 1159 int
 1160 in6_mc_join_locked(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1161     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1162     const int delay)
 1163 {
 1164         struct in6_mfilter       timf;
 1165         struct in6_multi        *inm;
 1166         int                      error;
 1167 #ifdef KTR
 1168         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1169 #endif
 1170 
 1171 #ifdef INVARIANTS
 1172         /*
 1173          * Sanity: Check scope zone ID was set for ifp, if and
 1174          * only if group is scoped to an interface.
 1175          */
 1176         KASSERT(IN6_IS_ADDR_MULTICAST(mcaddr),
 1177             ("%s: not a multicast address", __func__));
 1178         if (IN6_IS_ADDR_MC_LINKLOCAL(mcaddr) ||
 1179             IN6_IS_ADDR_MC_INTFACELOCAL(mcaddr)) {
 1180                 KASSERT(mcaddr->s6_addr16[1] != 0,
 1181                     ("%s: scope zone ID not set", __func__));
 1182         }
 1183 #endif
 1184 
 1185         IN6_MULTI_LOCK_ASSERT();
 1186 
 1187         CTR4(KTR_MLD, "%s: join %s on %p(%s))", __func__,
 1188             ip6_sprintf(ip6tbuf, mcaddr), ifp, if_name(ifp));
 1189 
 1190         error = 0;
 1191         inm = NULL;
 1192 
 1193         /*
 1194          * If no imf was specified (i.e. kernel consumer),
 1195          * fake one up and assume it is an ASM join.
 1196          */
 1197         if (imf == NULL) {
 1198                 im6f_init(&timf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 1199                 imf = &timf;
 1200         }
 1201 
 1202         error = in6_mc_get(ifp, mcaddr, &inm);
 1203         if (error) {
 1204                 CTR1(KTR_MLD, "%s: in6_mc_get() failure", __func__);
 1205                 return (error);
 1206         }
 1207 
 1208         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1209         error = in6m_merge(inm, imf);
 1210         if (error) {
 1211                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1212                 goto out_in6m_release;
 1213         }
 1214 
 1215         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1216         error = mld_change_state(inm, delay);
 1217         if (error) {
 1218                 CTR1(KTR_MLD, "%s: failed to update source", __func__);
 1219                 goto out_in6m_release;
 1220         }
 1221 
 1222 out_in6m_release:
 1223         if (error) {
 1224                 CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1225                 in6m_release_locked(inm);
 1226         } else {
 1227                 *pinm = inm;
 1228         }
 1229 
 1230         return (error);
 1231 }
 1232 
 1233 /*
 1234  * Leave a multicast group; unlocked entry point.
 1235  */
 1236 int
 1237 in6_mc_leave(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1238 {
 1239         struct ifnet *ifp;
 1240         int error;
 1241 
 1242         ifp = inm->in6m_ifp;
 1243 
 1244         IN6_MULTI_LOCK();
 1245         error = in6_mc_leave_locked(inm, imf);
 1246         IN6_MULTI_UNLOCK();
 1247 
 1248         return (error);
 1249 }
 1250 
 1251 /*
 1252  * Leave a multicast group; real entry point.
 1253  * All source filters will be expunged.
 1254  *
 1255  * Only preserves atomicity at inm level.
 1256  *
 1257  * Holding the write lock for the INP which contains imf
 1258  * is highly advisable. We can't assert for it as imf does not
 1259  * contain a back-pointer to the owning inp.
 1260  *
 1261  * Note: This is not the same as in6m_release(*) as this function also
 1262  * makes a state change downcall into MLD.
 1263  */
 1264 int
 1265 in6_mc_leave_locked(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1266 {
 1267         struct in6_mfilter       timf;
 1268         int                      error;
 1269 #ifdef KTR
 1270         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1271 #endif
 1272 
 1273         error = 0;
 1274 
 1275         IN6_MULTI_LOCK_ASSERT();
 1276 
 1277         CTR5(KTR_MLD, "%s: leave inm %p, %s/%s, imf %p", __func__,
 1278             inm, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 1279             (in6m_is_ifp_detached(inm) ? "null" : if_name(inm->in6m_ifp)),
 1280             imf);
 1281 
 1282         /*
 1283          * If no imf was specified (i.e. kernel consumer),
 1284          * fake one up and assume it is an ASM join.
 1285          */
 1286         if (imf == NULL) {
 1287                 im6f_init(&timf, MCAST_EXCLUDE, MCAST_UNDEFINED);
 1288                 imf = &timf;
 1289         }
 1290 
 1291         /*
 1292          * Begin state merge transaction at MLD layer.
 1293          *
 1294          * As this particular invocation should not cause any memory
 1295          * to be allocated, and there is no opportunity to roll back
 1296          * the transaction, it MUST NOT fail.
 1297          */
 1298         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1299         error = in6m_merge(inm, imf);
 1300         KASSERT(error == 0, ("%s: failed to merge inm state", __func__));
 1301 
 1302         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1303         error = mld_change_state(inm, 0);
 1304         if (error)
 1305                 CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1306 
 1307         CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1308         in6m_release_locked(inm);
 1309 
 1310         return (error);
 1311 }
 1312 
 1313 /*
 1314  * Block or unblock an ASM multicast source on an inpcb.
 1315  * This implements the delta-based API described in RFC 3678.
 1316  *
 1317  * The delta-based API applies only to exclusive-mode memberships.
 1318  * An MLD downcall will be performed.
 1319  *
 1320  * SMPng: NOTE: Must take Giant as a join may create a new ifma.
 1321  *
 1322  * Return 0 if successful, otherwise return an appropriate error code.
 1323  */
 1324 static int
 1325 in6p_block_unblock_source(struct inpcb *inp, struct sockopt *sopt)
 1326 {
 1327         struct group_source_req          gsr;
 1328         sockunion_t                     *gsa, *ssa;
 1329         struct ifnet                    *ifp;
 1330         struct in6_mfilter              *imf;
 1331         struct ip6_moptions             *imo;
 1332         struct in6_msource              *ims;
 1333         struct in6_multi                        *inm;
 1334         size_t                           idx;
 1335         uint16_t                         fmode;
 1336         int                              error, doblock;
 1337 #ifdef KTR
 1338         char                             ip6tbuf[INET6_ADDRSTRLEN];
 1339 #endif
 1340 
 1341         ifp = NULL;
 1342         error = 0;
 1343         doblock = 0;
 1344 
 1345         memset(&gsr, 0, sizeof(struct group_source_req));
 1346         gsa = (sockunion_t *)&gsr.gsr_group;
 1347         ssa = (sockunion_t *)&gsr.gsr_source;
 1348 
 1349         switch (sopt->sopt_name) {
 1350         case MCAST_BLOCK_SOURCE:
 1351         case MCAST_UNBLOCK_SOURCE:
 1352                 error = sooptcopyin(sopt, &gsr,
 1353                     sizeof(struct group_source_req),
 1354                     sizeof(struct group_source_req));
 1355                 if (error)
 1356                         return (error);
 1357 
 1358                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1359                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1360                         return (EINVAL);
 1361 
 1362                 if (ssa->sin6.sin6_family != AF_INET6 ||
 1363                     ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1364                         return (EINVAL);
 1365 
 1366                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1367                         return (EADDRNOTAVAIL);
 1368 
 1369                 ifp = ifnet_byindex(gsr.gsr_interface);
 1370 
 1371                 if (sopt->sopt_name == MCAST_BLOCK_SOURCE)
 1372                         doblock = 1;
 1373                 break;
 1374 
 1375         default:
 1376                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1377                     __func__, sopt->sopt_name);
 1378                 return (EOPNOTSUPP);
 1379                 break;
 1380         }
 1381 
 1382         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1383                 return (EINVAL);
 1384 
 1385         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1386 
 1387         /*
 1388          * Check if we are actually a member of this group.
 1389          */
 1390         imo = in6p_findmoptions(inp);
 1391         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1392         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1393                 error = EADDRNOTAVAIL;
 1394                 goto out_in6p_locked;
 1395         }
 1396 
 1397         KASSERT(imo->im6o_mfilters != NULL,
 1398             ("%s: im6o_mfilters not allocated", __func__));
 1399         imf = &imo->im6o_mfilters[idx];
 1400         inm = imo->im6o_membership[idx];
 1401 
 1402         /*
 1403          * Attempting to use the delta-based API on an
 1404          * non exclusive-mode membership is an error.
 1405          */
 1406         fmode = imf->im6f_st[0];
 1407         if (fmode != MCAST_EXCLUDE) {
 1408                 error = EINVAL;
 1409                 goto out_in6p_locked;
 1410         }
 1411 
 1412         /*
 1413          * Deal with error cases up-front:
 1414          *  Asked to block, but already blocked; or
 1415          *  Asked to unblock, but nothing to unblock.
 1416          * If adding a new block entry, allocate it.
 1417          */
 1418         ims = im6o_match_source(imo, idx, &ssa->sa);
 1419         if ((ims != NULL && doblock) || (ims == NULL && !doblock)) {
 1420                 CTR3(KTR_MLD, "%s: source %s %spresent", __func__,
 1421                     ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 1422                     doblock ? "" : "not ");
 1423                 error = EADDRNOTAVAIL;
 1424                 goto out_in6p_locked;
 1425         }
 1426 
 1427         INP_WLOCK_ASSERT(inp);
 1428 
 1429         /*
 1430          * Begin state merge transaction at socket layer.
 1431          */
 1432         if (doblock) {
 1433                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 1434                 ims = im6f_graft(imf, fmode, &ssa->sin6);
 1435                 if (ims == NULL)
 1436                         error = ENOMEM;
 1437         } else {
 1438                 CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 1439                 error = im6f_prune(imf, &ssa->sin6);
 1440         }
 1441 
 1442         if (error) {
 1443                 CTR1(KTR_MLD, "%s: merge imf state failed", __func__);
 1444                 goto out_im6f_rollback;
 1445         }
 1446 
 1447         /*
 1448          * Begin state merge transaction at MLD layer.
 1449          */
 1450         IN6_MULTI_LOCK();
 1451 
 1452         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1453         error = in6m_merge(inm, imf);
 1454         if (error)
 1455                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1456         else {
 1457                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1458                 error = mld_change_state(inm, 0);
 1459                 if (error)
 1460                         CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1461         }
 1462 
 1463         IN6_MULTI_UNLOCK();
 1464 
 1465 out_im6f_rollback:
 1466         if (error)
 1467                 im6f_rollback(imf);
 1468         else
 1469                 im6f_commit(imf);
 1470 
 1471         im6f_reap(imf);
 1472 
 1473 out_in6p_locked:
 1474         INP_WUNLOCK(inp);
 1475         return (error);
 1476 }
 1477 
 1478 /*
 1479  * Given an inpcb, return its multicast options structure pointer.  Accepts
 1480  * an unlocked inpcb pointer, but will return it locked.  May sleep.
 1481  *
 1482  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 1483  * SMPng: NOTE: Returns with the INP write lock held.
 1484  */
 1485 static struct ip6_moptions *
 1486 in6p_findmoptions(struct inpcb *inp)
 1487 {
 1488         struct ip6_moptions      *imo;
 1489         struct in6_multi                **immp;
 1490         struct in6_mfilter       *imfp;
 1491         size_t                    idx;
 1492 
 1493         INP_WLOCK(inp);
 1494         if (inp->in6p_moptions != NULL)
 1495                 return (inp->in6p_moptions);
 1496 
 1497         INP_WUNLOCK(inp);
 1498 
 1499         imo = malloc(sizeof(*imo), M_IP6MOPTS, M_WAITOK);
 1500         immp = malloc(sizeof(*immp) * IPV6_MIN_MEMBERSHIPS, M_IP6MOPTS,
 1501             M_WAITOK | M_ZERO);
 1502         imfp = malloc(sizeof(struct in6_mfilter) * IPV6_MIN_MEMBERSHIPS,
 1503             M_IN6MFILTER, M_WAITOK);
 1504 
 1505         imo->im6o_multicast_ifp = NULL;
 1506         imo->im6o_multicast_hlim = V_ip6_defmcasthlim;
 1507         imo->im6o_multicast_loop = in6_mcast_loop;
 1508         imo->im6o_num_memberships = 0;
 1509         imo->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
 1510         imo->im6o_membership = immp;
 1511 
 1512         /* Initialize per-group source filters. */
 1513         for (idx = 0; idx < IPV6_MIN_MEMBERSHIPS; idx++)
 1514                 im6f_init(&imfp[idx], MCAST_UNDEFINED, MCAST_EXCLUDE);
 1515         imo->im6o_mfilters = imfp;
 1516 
 1517         INP_WLOCK(inp);
 1518         if (inp->in6p_moptions != NULL) {
 1519                 free(imfp, M_IN6MFILTER);
 1520                 free(immp, M_IP6MOPTS);
 1521                 free(imo, M_IP6MOPTS);
 1522                 return (inp->in6p_moptions);
 1523         }
 1524         inp->in6p_moptions = imo;
 1525         return (imo);
 1526 }
 1527 
 1528 /*
 1529  * Discard the IPv6 multicast options (and source filters).
 1530  *
 1531  * SMPng: NOTE: assumes INP write lock is held.
 1532  */
 1533 void
 1534 ip6_freemoptions(struct ip6_moptions *imo)
 1535 {
 1536         struct in6_mfilter      *imf;
 1537         size_t                   idx, nmships;
 1538 
 1539         KASSERT(imo != NULL, ("%s: ip6_moptions is NULL", __func__));
 1540 
 1541         nmships = imo->im6o_num_memberships;
 1542         for (idx = 0; idx < nmships; ++idx) {
 1543                 imf = imo->im6o_mfilters ? &imo->im6o_mfilters[idx] : NULL;
 1544                 if (imf)
 1545                         im6f_leave(imf);
 1546                 /* XXX this will thrash the lock(s) */
 1547                 (void)in6_mc_leave(imo->im6o_membership[idx], imf);
 1548                 if (imf)
 1549                         im6f_purge(imf);
 1550         }
 1551 
 1552         if (imo->im6o_mfilters)
 1553                 free(imo->im6o_mfilters, M_IN6MFILTER);
 1554         free(imo->im6o_membership, M_IP6MOPTS);
 1555         free(imo, M_IP6MOPTS);
 1556 }
 1557 
 1558 /*
 1559  * Atomically get source filters on a socket for an IPv6 multicast group.
 1560  * Called with INP lock held; returns with lock released.
 1561  */
 1562 static int
 1563 in6p_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
 1564 {
 1565         struct __msfilterreq     msfr;
 1566         sockunion_t             *gsa;
 1567         struct ifnet            *ifp;
 1568         struct ip6_moptions     *imo;
 1569         struct in6_mfilter      *imf;
 1570         struct ip6_msource      *ims;
 1571         struct in6_msource      *lims;
 1572         struct sockaddr_in6     *psin;
 1573         struct sockaddr_storage *ptss;
 1574         struct sockaddr_storage *tss;
 1575         int                      error;
 1576         size_t                   idx, nsrcs, ncsrcs;
 1577 
 1578         INP_WLOCK_ASSERT(inp);
 1579 
 1580         imo = inp->in6p_moptions;
 1581         KASSERT(imo != NULL, ("%s: null ip6_moptions", __func__));
 1582 
 1583         INP_WUNLOCK(inp);
 1584 
 1585         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 1586             sizeof(struct __msfilterreq));
 1587         if (error)
 1588                 return (error);
 1589 
 1590         if (msfr.msfr_group.ss_family != AF_INET6 ||
 1591             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 1592                 return (EINVAL);
 1593 
 1594         gsa = (sockunion_t *)&msfr.msfr_group;
 1595         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1596                 return (EINVAL);
 1597 
 1598         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 1599                 return (EADDRNOTAVAIL);
 1600         ifp = ifnet_byindex(msfr.msfr_ifindex);
 1601         if (ifp == NULL)
 1602                 return (EADDRNOTAVAIL);
 1603         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1604 
 1605         INP_WLOCK(inp);
 1606 
 1607         /*
 1608          * Lookup group on the socket.
 1609          */
 1610         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1611         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1612                 INP_WUNLOCK(inp);
 1613                 return (EADDRNOTAVAIL);
 1614         }
 1615         imf = &imo->im6o_mfilters[idx];
 1616 
 1617         /*
 1618          * Ignore memberships which are in limbo.
 1619          */
 1620         if (imf->im6f_st[1] == MCAST_UNDEFINED) {
 1621                 INP_WUNLOCK(inp);
 1622                 return (EAGAIN);
 1623         }
 1624         msfr.msfr_fmode = imf->im6f_st[1];
 1625 
 1626         /*
 1627          * If the user specified a buffer, copy out the source filter
 1628          * entries to userland gracefully.
 1629          * We only copy out the number of entries which userland
 1630          * has asked for, but we always tell userland how big the
 1631          * buffer really needs to be.
 1632          */
 1633         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 1634                 msfr.msfr_nsrcs = in6_mcast_maxsocksrc;
 1635         tss = NULL;
 1636         if (msfr.msfr_srcs != NULL && msfr.msfr_nsrcs > 0) {
 1637                 tss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 1638                     M_TEMP, M_NOWAIT | M_ZERO);
 1639                 if (tss == NULL) {
 1640                         INP_WUNLOCK(inp);
 1641                         return (ENOBUFS);
 1642                 }
 1643         }
 1644 
 1645         /*
 1646          * Count number of sources in-mode at t0.
 1647          * If buffer space exists and remains, copy out source entries.
 1648          */
 1649         nsrcs = msfr.msfr_nsrcs;
 1650         ncsrcs = 0;
 1651         ptss = tss;
 1652         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
 1653                 lims = (struct in6_msource *)ims;
 1654                 if (lims->im6sl_st[0] == MCAST_UNDEFINED ||
 1655                     lims->im6sl_st[0] != imf->im6f_st[0])
 1656                         continue;
 1657                 ++ncsrcs;
 1658                 if (tss != NULL && nsrcs > 0) {
 1659                         psin = (struct sockaddr_in6 *)ptss;
 1660                         psin->sin6_family = AF_INET6;
 1661                         psin->sin6_len = sizeof(struct sockaddr_in6);
 1662                         psin->sin6_addr = lims->im6s_addr;
 1663                         psin->sin6_port = 0;
 1664                         --nsrcs;
 1665                         ++ptss;
 1666                 }
 1667         }
 1668 
 1669         INP_WUNLOCK(inp);
 1670 
 1671         if (tss != NULL) {
 1672                 error = copyout(tss, msfr.msfr_srcs,
 1673                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 1674                 free(tss, M_TEMP);
 1675                 if (error)
 1676                         return (error);
 1677         }
 1678 
 1679         msfr.msfr_nsrcs = ncsrcs;
 1680         error = sooptcopyout(sopt, &msfr, sizeof(struct __msfilterreq));
 1681 
 1682         return (error);
 1683 }
 1684 
 1685 /*
 1686  * Return the IP multicast options in response to user getsockopt().
 1687  */
 1688 int
 1689 ip6_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 1690 {
 1691         struct ip6_moptions     *im6o;
 1692         int                      error;
 1693         u_int                    optval;
 1694 
 1695         INP_WLOCK(inp);
 1696         im6o = inp->in6p_moptions;
 1697         /*
 1698          * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 1699          * or is a divert socket, reject it.
 1700          */
 1701         if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
 1702             (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
 1703             inp->inp_socket->so_proto->pr_type != SOCK_DGRAM)) {
 1704                 INP_WUNLOCK(inp);
 1705                 return (EOPNOTSUPP);
 1706         }
 1707 
 1708         error = 0;
 1709         switch (sopt->sopt_name) {
 1710         case IPV6_MULTICAST_IF:
 1711                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL) {
 1712                         optval = 0;
 1713                 } else {
 1714                         optval = im6o->im6o_multicast_ifp->if_index;
 1715                 }
 1716                 INP_WUNLOCK(inp);
 1717                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1718                 break;
 1719 
 1720         case IPV6_MULTICAST_HOPS:
 1721                 if (im6o == NULL)
 1722                         optval = V_ip6_defmcasthlim;
 1723                 else
 1724                         optval = im6o->im6o_multicast_hlim;
 1725                 INP_WUNLOCK(inp);
 1726                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1727                 break;
 1728 
 1729         case IPV6_MULTICAST_LOOP:
 1730                 if (im6o == NULL)
 1731                         optval = in6_mcast_loop; /* XXX VIMAGE */
 1732                 else
 1733                         optval = im6o->im6o_multicast_loop;
 1734                 INP_WUNLOCK(inp);
 1735                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1736                 break;
 1737 
 1738         case IPV6_MSFILTER:
 1739                 if (im6o == NULL) {
 1740                         error = EADDRNOTAVAIL;
 1741                         INP_WUNLOCK(inp);
 1742                 } else {
 1743                         error = in6p_get_source_filters(inp, sopt);
 1744                 }
 1745                 break;
 1746 
 1747         default:
 1748                 INP_WUNLOCK(inp);
 1749                 error = ENOPROTOOPT;
 1750                 break;
 1751         }
 1752 
 1753         INP_UNLOCK_ASSERT(inp);
 1754 
 1755         return (error);
 1756 }
 1757 
 1758 /*
 1759  * Look up the ifnet to use for a multicast group membership,
 1760  * given the address of an IPv6 group.
 1761  *
 1762  * This routine exists to support legacy IPv6 multicast applications.
 1763  *
 1764  * If inp is non-NULL, use this socket's current FIB number for any
 1765  * required FIB lookup. Look up the group address in the unicast FIB,
 1766  * and use its ifp; usually, this points to the default next-hop.
 1767  * If the FIB lookup fails, return NULL.
 1768  *
 1769  * FUTURE: Support multiple forwarding tables for IPv6.
 1770  *
 1771  * Returns NULL if no ifp could be found.
 1772  */
 1773 static struct ifnet *
 1774 in6p_lookup_mcast_ifp(const struct inpcb *in6p,
 1775     const struct sockaddr_in6 *gsin6)
 1776 {
 1777         struct nhop6_basic      nh6;
 1778         struct in6_addr         dst;
 1779         uint32_t                scopeid;
 1780         uint32_t                fibnum;
 1781 
 1782         KASSERT(in6p->inp_vflag & INP_IPV6,
 1783             ("%s: not INP_IPV6 inpcb", __func__));
 1784         KASSERT(gsin6->sin6_family == AF_INET6,
 1785             ("%s: not AF_INET6 group", __func__));
 1786 
 1787         in6_splitscope(&gsin6->sin6_addr, &dst, &scopeid);
 1788         fibnum = in6p ? in6p->inp_inc.inc_fibnum : RT_DEFAULT_FIB;
 1789         if (fib6_lookup_nh_basic(fibnum, &dst, scopeid, 0, 0, &nh6) != 0)
 1790                 return (NULL);
 1791 
 1792         return (nh6.nh_ifp);
 1793 }
 1794 
 1795 /*
 1796  * Join an IPv6 multicast group, possibly with a source.
 1797  *
 1798  * FIXME: The KAME use of the unspecified address (::)
 1799  * to join *all* multicast groups is currently unsupported.
 1800  */
 1801 static int
 1802 in6p_join_group(struct inpcb *inp, struct sockopt *sopt)
 1803 {
 1804         struct group_source_req          gsr;
 1805         sockunion_t                     *gsa, *ssa;
 1806         struct ifnet                    *ifp;
 1807         struct in6_mfilter              *imf;
 1808         struct ip6_moptions             *imo;
 1809         struct in6_multi                *inm;
 1810         struct in6_msource              *lims;
 1811         size_t                           idx;
 1812         int                              error, is_new;
 1813 
 1814         ifp = NULL;
 1815         imf = NULL;
 1816         lims = NULL;
 1817         error = 0;
 1818         is_new = 0;
 1819 
 1820         memset(&gsr, 0, sizeof(struct group_source_req));
 1821         gsa = (sockunion_t *)&gsr.gsr_group;
 1822         gsa->ss.ss_family = AF_UNSPEC;
 1823         ssa = (sockunion_t *)&gsr.gsr_source;
 1824         ssa->ss.ss_family = AF_UNSPEC;
 1825 
 1826         /*
 1827          * Chew everything into struct group_source_req.
 1828          * Overwrite the port field if present, as the sockaddr
 1829          * being copied in may be matched with a binary comparison.
 1830          * Ignore passed-in scope ID.
 1831          */
 1832         switch (sopt->sopt_name) {
 1833         case IPV6_JOIN_GROUP: {
 1834                 struct ipv6_mreq mreq;
 1835 
 1836                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 1837                     sizeof(struct ipv6_mreq));
 1838                 if (error)
 1839                         return (error);
 1840 
 1841                 gsa->sin6.sin6_family = AF_INET6;
 1842                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 1843                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 1844 
 1845                 if (mreq.ipv6mr_interface == 0) {
 1846                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 1847                 } else {
 1848                         if (V_if_index < mreq.ipv6mr_interface)
 1849                                 return (EADDRNOTAVAIL);
 1850                         ifp = ifnet_byindex(mreq.ipv6mr_interface);
 1851                 }
 1852                 CTR3(KTR_MLD, "%s: ipv6mr_interface = %d, ifp = %p",
 1853                     __func__, mreq.ipv6mr_interface, ifp);
 1854         } break;
 1855 
 1856         case MCAST_JOIN_GROUP:
 1857         case MCAST_JOIN_SOURCE_GROUP:
 1858                 if (sopt->sopt_name == MCAST_JOIN_GROUP) {
 1859                         error = sooptcopyin(sopt, &gsr,
 1860                             sizeof(struct group_req),
 1861                             sizeof(struct group_req));
 1862                 } else if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1863                         error = sooptcopyin(sopt, &gsr,
 1864                             sizeof(struct group_source_req),
 1865                             sizeof(struct group_source_req));
 1866                 }
 1867                 if (error)
 1868                         return (error);
 1869 
 1870                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1871                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1872                         return (EINVAL);
 1873 
 1874                 if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1875                         if (ssa->sin6.sin6_family != AF_INET6 ||
 1876                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1877                                 return (EINVAL);
 1878                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 1879                                 return (EINVAL);
 1880                         /*
 1881                          * TODO: Validate embedded scope ID in source
 1882                          * list entry against passed-in ifp, if and only
 1883                          * if source list filter entry is iface or node local.
 1884                          */
 1885                         in6_clearscope(&ssa->sin6.sin6_addr);
 1886                         ssa->sin6.sin6_port = 0;
 1887                         ssa->sin6.sin6_scope_id = 0;
 1888                 }
 1889 
 1890                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1891                         return (EADDRNOTAVAIL);
 1892                 ifp = ifnet_byindex(gsr.gsr_interface);
 1893                 break;
 1894 
 1895         default:
 1896                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1897                     __func__, sopt->sopt_name);
 1898                 return (EOPNOTSUPP);
 1899                 break;
 1900         }
 1901 
 1902         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1903                 return (EINVAL);
 1904 
 1905         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
 1906                 return (EADDRNOTAVAIL);
 1907 
 1908         gsa->sin6.sin6_port = 0;
 1909         gsa->sin6.sin6_scope_id = 0;
 1910 
 1911         /*
 1912          * Always set the scope zone ID on memberships created from userland.
 1913          * Use the passed-in ifp to do this.
 1914          * XXX The in6_setscope() return value is meaningless.
 1915          * XXX SCOPE6_LOCK() is taken by in6_setscope().
 1916          */
 1917         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1918 
 1919         imo = in6p_findmoptions(inp);
 1920         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1921         if (idx == -1) {
 1922                 is_new = 1;
 1923         } else {
 1924                 inm = imo->im6o_membership[idx];
 1925                 imf = &imo->im6o_mfilters[idx];
 1926                 if (ssa->ss.ss_family != AF_UNSPEC) {
 1927                         /*
 1928                          * MCAST_JOIN_SOURCE_GROUP on an exclusive membership
 1929                          * is an error. On an existing inclusive membership,
 1930                          * it just adds the source to the filter list.
 1931                          */
 1932                         if (imf->im6f_st[1] != MCAST_INCLUDE) {
 1933                                 error = EINVAL;
 1934                                 goto out_in6p_locked;
 1935                         }
 1936                         /*
 1937                          * Throw out duplicates.
 1938                          *
 1939                          * XXX FIXME: This makes a naive assumption that
 1940                          * even if entries exist for *ssa in this imf,
 1941                          * they will be rejected as dupes, even if they
 1942                          * are not valid in the current mode (in-mode).
 1943                          *
 1944                          * in6_msource is transactioned just as for anything
 1945                          * else in SSM -- but note naive use of in6m_graft()
 1946                          * below for allocating new filter entries.
 1947                          *
 1948                          * This is only an issue if someone mixes the
 1949                          * full-state SSM API with the delta-based API,
 1950                          * which is discouraged in the relevant RFCs.
 1951                          */
 1952                         lims = im6o_match_source(imo, idx, &ssa->sa);
 1953                         if (lims != NULL /*&&
 1954                             lims->im6sl_st[1] == MCAST_INCLUDE*/) {
 1955                                 error = EADDRNOTAVAIL;
 1956                                 goto out_in6p_locked;
 1957                         }
 1958                 } else {
 1959                         /*
 1960                          * MCAST_JOIN_GROUP alone, on any existing membership,
 1961                          * is rejected, to stop the same inpcb tying up
 1962                          * multiple refs to the in_multi.
 1963                          * On an existing inclusive membership, this is also
 1964                          * an error; if you want to change filter mode,
 1965                          * you must use the userland API setsourcefilter().
 1966                          * XXX We don't reject this for imf in UNDEFINED
 1967                          * state at t1, because allocation of a filter
 1968                          * is atomic with allocation of a membership.
 1969                          */
 1970                         error = EINVAL;
 1971                         goto out_in6p_locked;
 1972                 }
 1973         }
 1974 
 1975         /*
 1976          * Begin state merge transaction at socket layer.
 1977          */
 1978         INP_WLOCK_ASSERT(inp);
 1979 
 1980         if (is_new) {
 1981                 if (imo->im6o_num_memberships == imo->im6o_max_memberships) {
 1982                         error = im6o_grow(imo);
 1983                         if (error)
 1984                                 goto out_in6p_locked;
 1985                 }
 1986                 /*
 1987                  * Allocate the new slot upfront so we can deal with
 1988                  * grafting the new source filter in same code path
 1989                  * as for join-source on existing membership.
 1990                  */
 1991                 idx = imo->im6o_num_memberships;
 1992                 imo->im6o_membership[idx] = NULL;
 1993                 imo->im6o_num_memberships++;
 1994                 KASSERT(imo->im6o_mfilters != NULL,
 1995                     ("%s: im6f_mfilters vector was not allocated", __func__));
 1996                 imf = &imo->im6o_mfilters[idx];
 1997                 KASSERT(RB_EMPTY(&imf->im6f_sources),
 1998                     ("%s: im6f_sources not empty", __func__));
 1999         }
 2000 
 2001         /*
 2002          * Graft new source into filter list for this inpcb's
 2003          * membership of the group. The in6_multi may not have
 2004          * been allocated yet if this is a new membership, however,
 2005          * the in_mfilter slot will be allocated and must be initialized.
 2006          *
 2007          * Note: Grafting of exclusive mode filters doesn't happen
 2008          * in this path.
 2009          * XXX: Should check for non-NULL lims (node exists but may
 2010          * not be in-mode) for interop with full-state API.
 2011          */
 2012         if (ssa->ss.ss_family != AF_UNSPEC) {
 2013                 /* Membership starts in IN mode */
 2014                 if (is_new) {
 2015                         CTR1(KTR_MLD, "%s: new join w/source", __func__);
 2016                         im6f_init(imf, MCAST_UNDEFINED, MCAST_INCLUDE);
 2017                 } else {
 2018                         CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 2019                 }
 2020                 lims = im6f_graft(imf, MCAST_INCLUDE, &ssa->sin6);
 2021                 if (lims == NULL) {
 2022                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2023                             __func__);
 2024                         error = ENOMEM;
 2025                         goto out_im6o_free;
 2026                 }
 2027         } else {
 2028                 /* No address specified; Membership starts in EX mode */
 2029                 if (is_new) {
 2030                         CTR1(KTR_MLD, "%s: new join w/o source", __func__);
 2031                         im6f_init(imf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 2032                 }
 2033         }
 2034 
 2035         /*
 2036          * Begin state merge transaction at MLD layer.
 2037          */
 2038         IN6_MULTI_LOCK();
 2039 
 2040         if (is_new) {
 2041                 error = in6_mc_join_locked(ifp, &gsa->sin6.sin6_addr, imf,
 2042                     &inm, 0);
 2043                 if (error) {
 2044                         IN6_MULTI_UNLOCK();
 2045                         goto out_im6o_free;
 2046                 }
 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                 else {
 2055                         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2056                         error = mld_change_state(inm, 0);
 2057                         if (error)
 2058                                 CTR1(KTR_MLD, "%s: failed mld downcall",
 2059                                     __func__);
 2060                 }
 2061         }
 2062 
 2063         IN6_MULTI_UNLOCK();
 2064         INP_WLOCK_ASSERT(inp);
 2065         if (error) {
 2066                 im6f_rollback(imf);
 2067                 if (is_new)
 2068                         im6f_purge(imf);
 2069                 else
 2070                         im6f_reap(imf);
 2071         } else {
 2072                 im6f_commit(imf);
 2073         }
 2074 
 2075 out_im6o_free:
 2076         if (error && is_new) {
 2077                 imo->im6o_membership[idx] = NULL;
 2078                 --imo->im6o_num_memberships;
 2079         }
 2080 
 2081 out_in6p_locked:
 2082         INP_WUNLOCK(inp);
 2083         return (error);
 2084 }
 2085 
 2086 /*
 2087  * Leave an IPv6 multicast group on an inpcb, possibly with a source.
 2088  */
 2089 static int
 2090 in6p_leave_group(struct inpcb *inp, struct sockopt *sopt)
 2091 {
 2092         struct ipv6_mreq                 mreq;
 2093         struct group_source_req          gsr;
 2094         sockunion_t                     *gsa, *ssa;
 2095         struct ifnet                    *ifp;
 2096         struct in6_mfilter              *imf;
 2097         struct ip6_moptions             *imo;
 2098         struct in6_msource              *ims;
 2099         struct in6_multi                *inm;
 2100         uint32_t                         ifindex;
 2101         size_t                           idx;
 2102         int                              error, is_final;
 2103 #ifdef KTR
 2104         char                             ip6tbuf[INET6_ADDRSTRLEN];
 2105 #endif
 2106 
 2107         ifp = NULL;
 2108         ifindex = 0;
 2109         error = 0;
 2110         is_final = 1;
 2111 
 2112         memset(&gsr, 0, sizeof(struct group_source_req));
 2113         gsa = (sockunion_t *)&gsr.gsr_group;
 2114         gsa->ss.ss_family = AF_UNSPEC;
 2115         ssa = (sockunion_t *)&gsr.gsr_source;
 2116         ssa->ss.ss_family = AF_UNSPEC;
 2117 
 2118         /*
 2119          * Chew everything passed in up into a struct group_source_req
 2120          * as that is easier to process.
 2121          * Note: Any embedded scope ID in the multicast group passed
 2122          * in by userland is ignored, the interface index is the recommended
 2123          * mechanism to specify an interface; see below.
 2124          */
 2125         switch (sopt->sopt_name) {
 2126         case IPV6_LEAVE_GROUP:
 2127                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 2128                     sizeof(struct ipv6_mreq));
 2129                 if (error)
 2130                         return (error);
 2131                 gsa->sin6.sin6_family = AF_INET6;
 2132                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 2133                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 2134                 gsa->sin6.sin6_port = 0;
 2135                 gsa->sin6.sin6_scope_id = 0;
 2136                 ifindex = mreq.ipv6mr_interface;
 2137                 break;
 2138 
 2139         case MCAST_LEAVE_GROUP:
 2140         case MCAST_LEAVE_SOURCE_GROUP:
 2141                 if (sopt->sopt_name == MCAST_LEAVE_GROUP) {
 2142                         error = sooptcopyin(sopt, &gsr,
 2143                             sizeof(struct group_req),
 2144                             sizeof(struct group_req));
 2145                 } else if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2146                         error = sooptcopyin(sopt, &gsr,
 2147                             sizeof(struct group_source_req),
 2148                             sizeof(struct group_source_req));
 2149                 }
 2150                 if (error)
 2151                         return (error);
 2152 
 2153                 if (gsa->sin6.sin6_family != AF_INET6 ||
 2154                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2155                         return (EINVAL);
 2156                 if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2157                         if (ssa->sin6.sin6_family != AF_INET6 ||
 2158                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2159                                 return (EINVAL);
 2160                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 2161                                 return (EINVAL);
 2162                         /*
 2163                          * TODO: Validate embedded scope ID in source
 2164                          * list entry against passed-in ifp, if and only
 2165                          * if source list filter entry is iface or node local.
 2166                          */
 2167                         in6_clearscope(&ssa->sin6.sin6_addr);
 2168                 }
 2169                 gsa->sin6.sin6_port = 0;
 2170                 gsa->sin6.sin6_scope_id = 0;
 2171                 ifindex = gsr.gsr_interface;
 2172                 break;
 2173 
 2174         default:
 2175                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 2176                     __func__, sopt->sopt_name);
 2177                 return (EOPNOTSUPP);
 2178                 break;
 2179         }
 2180 
 2181         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2182                 return (EINVAL);
 2183 
 2184         /*
 2185          * Validate interface index if provided. If no interface index
 2186          * was provided separately, attempt to look the membership up
 2187          * from the default scope as a last resort to disambiguate
 2188          * the membership we are being asked to leave.
 2189          * XXX SCOPE6 lock potentially taken here.
 2190          */
 2191         if (ifindex != 0) {
 2192                 if (V_if_index < ifindex)
 2193                         return (EADDRNOTAVAIL);
 2194                 ifp = ifnet_byindex(ifindex);
 2195                 if (ifp == NULL)
 2196                         return (EADDRNOTAVAIL);
 2197                 (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2198         } else {
 2199                 error = sa6_embedscope(&gsa->sin6, V_ip6_use_defzone);
 2200                 if (error)
 2201                         return (EADDRNOTAVAIL);
 2202                 /*
 2203                  * Some badly behaved applications don't pass an ifindex
 2204                  * or a scope ID, which is an API violation. In this case,
 2205                  * perform a lookup as per a v6 join.
 2206                  *
 2207                  * XXX For now, stomp on zone ID for the corner case.
 2208                  * This is not the 'KAME way', but we need to see the ifp
 2209                  * directly until such time as this implementation is
 2210                  * refactored, assuming the scope IDs are the way to go.
 2211                  */
 2212                 ifindex = ntohs(gsa->sin6.sin6_addr.s6_addr16[1]);
 2213                 if (ifindex == 0) {
 2214                         CTR2(KTR_MLD, "%s: warning: no ifindex, looking up "
 2215                             "ifp for group %s.", __func__,
 2216                             ip6_sprintf(ip6tbuf, &gsa->sin6.sin6_addr));
 2217                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 2218                 } else {
 2219                         ifp = ifnet_byindex(ifindex);
 2220                 }
 2221                 if (ifp == NULL)
 2222                         return (EADDRNOTAVAIL);
 2223         }
 2224 
 2225         CTR2(KTR_MLD, "%s: ifp = %p", __func__, ifp);
 2226         KASSERT(ifp != NULL, ("%s: ifp did not resolve", __func__));
 2227 
 2228         /*
 2229          * Find the membership in the membership array.
 2230          */
 2231         imo = in6p_findmoptions(inp);
 2232         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2233         if (idx == -1) {
 2234                 error = EADDRNOTAVAIL;
 2235                 goto out_in6p_locked;
 2236         }
 2237         inm = imo->im6o_membership[idx];
 2238         imf = &imo->im6o_mfilters[idx];
 2239 
 2240         if (ssa->ss.ss_family != AF_UNSPEC)
 2241                 is_final = 0;
 2242 
 2243         /*
 2244          * Begin state merge transaction at socket layer.
 2245          */
 2246         INP_WLOCK_ASSERT(inp);
 2247 
 2248         /*
 2249          * If we were instructed only to leave a given source, do so.
 2250          * MCAST_LEAVE_SOURCE_GROUP is only valid for inclusive memberships.
 2251          */
 2252         if (is_final) {
 2253                 im6f_leave(imf);
 2254         } else {
 2255                 if (imf->im6f_st[0] == MCAST_EXCLUDE) {
 2256                         error = EADDRNOTAVAIL;
 2257                         goto out_in6p_locked;
 2258                 }
 2259                 ims = im6o_match_source(imo, idx, &ssa->sa);
 2260                 if (ims == NULL) {
 2261                         CTR3(KTR_MLD, "%s: source %p %spresent", __func__,
 2262                             ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 2263                             "not ");
 2264                         error = EADDRNOTAVAIL;
 2265                         goto out_in6p_locked;
 2266                 }
 2267                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 2268                 error = im6f_prune(imf, &ssa->sin6);
 2269                 if (error) {
 2270                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2271                             __func__);
 2272                         goto out_in6p_locked;
 2273                 }
 2274         }
 2275 
 2276         /*
 2277          * Begin state merge transaction at MLD layer.
 2278          */
 2279         IN6_MULTI_LOCK();
 2280 
 2281         if (is_final) {
 2282                 /*
 2283                  * Give up the multicast address record to which
 2284                  * the membership points.
 2285                  */
 2286                 (void)in6_mc_leave_locked(inm, imf);
 2287         } else {
 2288                 CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2289                 error = in6m_merge(inm, imf);
 2290                 if (error)
 2291                         CTR1(KTR_MLD, "%s: failed to merge inm state",
 2292                             __func__);
 2293                 else {
 2294                         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2295                         error = mld_change_state(inm, 0);
 2296                         if (error)
 2297                                 CTR1(KTR_MLD, "%s: failed mld downcall",
 2298                                     __func__);
 2299                 }
 2300         }
 2301 
 2302         IN6_MULTI_UNLOCK();
 2303 
 2304         if (error)
 2305                 im6f_rollback(imf);
 2306         else
 2307                 im6f_commit(imf);
 2308 
 2309         im6f_reap(imf);
 2310 
 2311         if (is_final) {
 2312                 /* Remove the gap in the membership array. */
 2313                 KASSERT(RB_EMPTY(&imf->im6f_sources),
 2314                     ("%s: im6f_sources not empty", __func__));
 2315                 for (++idx; idx < imo->im6o_num_memberships; ++idx) {
 2316                         imo->im6o_membership[idx - 1] = imo->im6o_membership[idx];
 2317                         imo->im6o_mfilters[idx - 1] = imo->im6o_mfilters[idx];
 2318                 }
 2319                 im6f_init(&imo->im6o_mfilters[idx - 1], MCAST_UNDEFINED,
 2320                     MCAST_EXCLUDE);
 2321                 imo->im6o_num_memberships--;
 2322         }
 2323 
 2324 out_in6p_locked:
 2325         INP_WUNLOCK(inp);
 2326         return (error);
 2327 }
 2328 
 2329 /*
 2330  * Select the interface for transmitting IPv6 multicast datagrams.
 2331  *
 2332  * Either an instance of struct in6_addr or an instance of struct ipv6_mreqn
 2333  * may be passed to this socket option. An address of in6addr_any or an
 2334  * interface index of 0 is used to remove a previous selection.
 2335  * When no interface is selected, one is chosen for every send.
 2336  */
 2337 static int
 2338 in6p_set_multicast_if(struct inpcb *inp, struct sockopt *sopt)
 2339 {
 2340         struct ifnet            *ifp;
 2341         struct ip6_moptions     *imo;
 2342         u_int                    ifindex;
 2343         int                      error;
 2344 
 2345         if (sopt->sopt_valsize != sizeof(u_int))
 2346                 return (EINVAL);
 2347 
 2348         error = sooptcopyin(sopt, &ifindex, sizeof(u_int), sizeof(u_int));
 2349         if (error)
 2350                 return (error);
 2351         if (V_if_index < ifindex)
 2352                 return (EINVAL);
 2353         if (ifindex == 0)
 2354                 ifp = NULL;
 2355         else {
 2356                 ifp = ifnet_byindex(ifindex);
 2357                 if (ifp == NULL)
 2358                         return (EINVAL);
 2359                 if ((ifp->if_flags & IFF_MULTICAST) == 0)
 2360                         return (EADDRNOTAVAIL);
 2361         }
 2362         imo = in6p_findmoptions(inp);
 2363         imo->im6o_multicast_ifp = ifp;
 2364         INP_WUNLOCK(inp);
 2365 
 2366         return (0);
 2367 }
 2368 
 2369 /*
 2370  * Atomically set source filters on a socket for an IPv6 multicast group.
 2371  *
 2372  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 2373  */
 2374 static int
 2375 in6p_set_source_filters(struct inpcb *inp, struct sockopt *sopt)
 2376 {
 2377         struct __msfilterreq     msfr;
 2378         sockunion_t             *gsa;
 2379         struct ifnet            *ifp;
 2380         struct in6_mfilter      *imf;
 2381         struct ip6_moptions     *imo;
 2382         struct in6_multi                *inm;
 2383         size_t                   idx;
 2384         int                      error;
 2385 
 2386         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 2387             sizeof(struct __msfilterreq));
 2388         if (error)
 2389                 return (error);
 2390 
 2391         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 2392                 return (ENOBUFS);
 2393 
 2394         if (msfr.msfr_fmode != MCAST_EXCLUDE &&
 2395             msfr.msfr_fmode != MCAST_INCLUDE)
 2396                 return (EINVAL);
 2397 
 2398         if (msfr.msfr_group.ss_family != AF_INET6 ||
 2399             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 2400                 return (EINVAL);
 2401 
 2402         gsa = (sockunion_t *)&msfr.msfr_group;
 2403         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2404                 return (EINVAL);
 2405 
 2406         gsa->sin6.sin6_port = 0;        /* ignore port */
 2407 
 2408         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 2409                 return (EADDRNOTAVAIL);
 2410         ifp = ifnet_byindex(msfr.msfr_ifindex);
 2411         if (ifp == NULL)
 2412                 return (EADDRNOTAVAIL);
 2413         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2414 
 2415         /*
 2416          * Take the INP write lock.
 2417          * Check if this socket is a member of this group.
 2418          */
 2419         imo = in6p_findmoptions(inp);
 2420         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2421         if (idx == -1 || imo->im6o_mfilters == NULL) {
 2422                 error = EADDRNOTAVAIL;
 2423                 goto out_in6p_locked;
 2424         }
 2425         inm = imo->im6o_membership[idx];
 2426         imf = &imo->im6o_mfilters[idx];
 2427 
 2428         /*
 2429          * Begin state merge transaction at socket layer.
 2430          */
 2431         INP_WLOCK_ASSERT(inp);
 2432 
 2433         imf->im6f_st[1] = msfr.msfr_fmode;
 2434 
 2435         /*
 2436          * Apply any new source filters, if present.
 2437          * Make a copy of the user-space source vector so
 2438          * that we may copy them with a single copyin. This
 2439          * allows us to deal with page faults up-front.
 2440          */
 2441         if (msfr.msfr_nsrcs > 0) {
 2442                 struct in6_msource      *lims;
 2443                 struct sockaddr_in6     *psin;
 2444                 struct sockaddr_storage *kss, *pkss;
 2445                 int                      i;
 2446 
 2447                 INP_WUNLOCK(inp);
 2448  
 2449                 CTR2(KTR_MLD, "%s: loading %lu source list entries",
 2450                     __func__, (unsigned long)msfr.msfr_nsrcs);
 2451                 kss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 2452                     M_TEMP, M_WAITOK);
 2453                 error = copyin(msfr.msfr_srcs, kss,
 2454                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 2455                 if (error) {
 2456                         free(kss, M_TEMP);
 2457                         return (error);
 2458                 }
 2459 
 2460                 INP_WLOCK(inp);
 2461 
 2462                 /*
 2463                  * Mark all source filters as UNDEFINED at t1.
 2464                  * Restore new group filter mode, as im6f_leave()
 2465                  * will set it to INCLUDE.
 2466                  */
 2467                 im6f_leave(imf);
 2468                 imf->im6f_st[1] = msfr.msfr_fmode;
 2469 
 2470                 /*
 2471                  * Update socket layer filters at t1, lazy-allocating
 2472                  * new entries. This saves a bunch of memory at the
 2473                  * cost of one RB_FIND() per source entry; duplicate
 2474                  * entries in the msfr_nsrcs vector are ignored.
 2475                  * If we encounter an error, rollback transaction.
 2476                  *
 2477                  * XXX This too could be replaced with a set-symmetric
 2478                  * difference like loop to avoid walking from root
 2479                  * every time, as the key space is common.
 2480                  */
 2481                 for (i = 0, pkss = kss; i < msfr.msfr_nsrcs; i++, pkss++) {
 2482                         psin = (struct sockaddr_in6 *)pkss;
 2483                         if (psin->sin6_family != AF_INET6) {
 2484                                 error = EAFNOSUPPORT;
 2485                                 break;
 2486                         }
 2487                         if (psin->sin6_len != sizeof(struct sockaddr_in6)) {
 2488                                 error = EINVAL;
 2489                                 break;
 2490                         }
 2491                         if (IN6_IS_ADDR_MULTICAST(&psin->sin6_addr)) {
 2492                                 error = EINVAL;
 2493                                 break;
 2494                         }
 2495                         /*
 2496                          * TODO: Validate embedded scope ID in source
 2497                          * list entry against passed-in ifp, if and only
 2498                          * if source list filter entry is iface or node local.
 2499                          */
 2500                         in6_clearscope(&psin->sin6_addr);
 2501                         error = im6f_get_source(imf, psin, &lims);
 2502                         if (error)
 2503                                 break;
 2504                         lims->im6sl_st[1] = imf->im6f_st[1];
 2505                 }
 2506                 free(kss, M_TEMP);
 2507         }
 2508 
 2509         if (error)
 2510                 goto out_im6f_rollback;
 2511 
 2512         INP_WLOCK_ASSERT(inp);
 2513         IN6_MULTI_LOCK();
 2514 
 2515         /*
 2516          * Begin state merge transaction at MLD layer.
 2517          */
 2518         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2519         error = in6m_merge(inm, imf);
 2520         if (error)
 2521                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 2522         else {
 2523                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2524                 error = mld_change_state(inm, 0);
 2525                 if (error)
 2526                         CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 2527         }
 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             if_name(inm->in6m_ifp),
 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             mbufq_len(&inm->in6m_scq));
 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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