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


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

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    1 /*
    2  * Copyright (c) 2009 Bruce Simpson.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. The name of the author may not be used to endorse or promote
   14  *    products derived from this software without specific prior written
   15  *    permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 /*
   31  * IPv6 multicast socket, group, and socket option processing module.
   32  * Normative references: RFC 2292, RFC 3492, RFC 3542, RFC 3678, RFC 3810.
   33  */
   34 
   35 #include <sys/cdefs.h>
   36 __FBSDID("$FreeBSD: releng/11.1/sys/netinet6/in6_mcast.c 298995 2016-05-03 18:05:43Z pfg $");
   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         /* Increment ASM listener count on transition to ASM mode. */
 1008         if (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 == 0) {
 1009                 CTR1(KTR_MLD, "%s: asm++ on inm at t1", __func__);
 1010                 inm->in6m_st[1].iss_asm++;
 1011         }
 1012 
 1013         CTR3(KTR_MLD, "%s: merged imf %p to inm %p", __func__, imf, inm);
 1014         in6m_print(inm);
 1015 
 1016 out_reap:
 1017         if (schanged > 0) {
 1018                 CTR1(KTR_MLD, "%s: sources changed; reaping", __func__);
 1019                 in6m_reap(inm);
 1020         }
 1021         return (error);
 1022 }
 1023 
 1024 /*
 1025  * Mark an in6_multi's filter set deltas as committed.
 1026  * Called by MLD after a state change has been enqueued.
 1027  */
 1028 void
 1029 in6m_commit(struct in6_multi *inm)
 1030 {
 1031         struct ip6_msource      *ims;
 1032 
 1033         CTR2(KTR_MLD, "%s: commit inm %p", __func__, inm);
 1034         CTR1(KTR_MLD, "%s: pre commit:", __func__);
 1035         in6m_print(inm);
 1036 
 1037         RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
 1038                 ims->im6s_st[0] = ims->im6s_st[1];
 1039         }
 1040         inm->in6m_st[0] = inm->in6m_st[1];
 1041 }
 1042 
 1043 /*
 1044  * Reap unreferenced nodes from an in6_multi's filter set.
 1045  */
 1046 static void
 1047 in6m_reap(struct in6_multi *inm)
 1048 {
 1049         struct ip6_msource      *ims, *tims;
 1050 
 1051         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1052                 if (ims->im6s_st[0].ex > 0 || ims->im6s_st[0].in > 0 ||
 1053                     ims->im6s_st[1].ex > 0 || ims->im6s_st[1].in > 0 ||
 1054                     ims->im6s_stp != 0)
 1055                         continue;
 1056                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1057                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1058                 free(ims, M_IP6MSOURCE);
 1059                 inm->in6m_nsrc--;
 1060         }
 1061 }
 1062 
 1063 /*
 1064  * Purge all source nodes from an in6_multi's filter set.
 1065  */
 1066 static void
 1067 in6m_purge(struct in6_multi *inm)
 1068 {
 1069         struct ip6_msource      *ims, *tims;
 1070 
 1071         RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs, tims) {
 1072                 CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
 1073                 RB_REMOVE(ip6_msource_tree, &inm->in6m_srcs, ims);
 1074                 free(ims, M_IP6MSOURCE);
 1075                 inm->in6m_nsrc--;
 1076         }
 1077         /* Free state-change requests that might be queued. */
 1078         mbufq_drain(&inm->in6m_scq);
 1079 }
 1080 
 1081 /*
 1082  * Join a multicast address w/o sources.
 1083  * KAME compatibility entry point.
 1084  *
 1085  * SMPng: Assume no mc locks held by caller.
 1086  */
 1087 struct in6_multi_mship *
 1088 in6_joingroup(struct ifnet *ifp, struct in6_addr *mcaddr,
 1089     int *errorp, int delay)
 1090 {
 1091         struct in6_multi_mship *imm;
 1092         int error;
 1093 
 1094         imm = malloc(sizeof(*imm), M_IP6MADDR, M_NOWAIT);
 1095         if (imm == NULL) {
 1096                 *errorp = ENOBUFS;
 1097                 return (NULL);
 1098         }
 1099 
 1100         delay = (delay * PR_FASTHZ) / hz;
 1101 
 1102         error = in6_mc_join(ifp, mcaddr, NULL, &imm->i6mm_maddr, delay);
 1103         if (error) {
 1104                 *errorp = error;
 1105                 free(imm, M_IP6MADDR);
 1106                 return (NULL);
 1107         }
 1108 
 1109         return (imm);
 1110 }
 1111 
 1112 /*
 1113  * Leave a multicast address w/o sources.
 1114  * KAME compatibility entry point.
 1115  *
 1116  * SMPng: Assume no mc locks held by caller.
 1117  */
 1118 int
 1119 in6_leavegroup(struct in6_multi_mship *imm)
 1120 {
 1121 
 1122         if (imm->i6mm_maddr != NULL)
 1123                 in6_mc_leave(imm->i6mm_maddr, NULL);
 1124         free(imm,  M_IP6MADDR);
 1125         return 0;
 1126 }
 1127 
 1128 /*
 1129  * Join a multicast group; unlocked entry point.
 1130  *
 1131  * SMPng: XXX: in6_mc_join() is called from in6_control() when upper
 1132  * locks are not held. Fortunately, ifp is unlikely to have been detached
 1133  * at this point, so we assume it's OK to recurse.
 1134  */
 1135 int
 1136 in6_mc_join(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1137     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1138     const int delay)
 1139 {
 1140         int error;
 1141 
 1142         IN6_MULTI_LOCK();
 1143         error = in6_mc_join_locked(ifp, mcaddr, imf, pinm, delay);
 1144         IN6_MULTI_UNLOCK();
 1145 
 1146         return (error);
 1147 }
 1148 
 1149 /*
 1150  * Join a multicast group; real entry point.
 1151  *
 1152  * Only preserves atomicity at inm level.
 1153  * NOTE: imf argument cannot be const due to sys/tree.h limitations.
 1154  *
 1155  * If the MLD downcall fails, the group is not joined, and an error
 1156  * code is returned.
 1157  */
 1158 int
 1159 in6_mc_join_locked(struct ifnet *ifp, const struct in6_addr *mcaddr,
 1160     /*const*/ struct in6_mfilter *imf, struct in6_multi **pinm,
 1161     const int delay)
 1162 {
 1163         struct in6_mfilter       timf;
 1164         struct in6_multi        *inm;
 1165         int                      error;
 1166 #ifdef KTR
 1167         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1168 #endif
 1169 
 1170 #ifdef INVARIANTS
 1171         /*
 1172          * Sanity: Check scope zone ID was set for ifp, if and
 1173          * only if group is scoped to an interface.
 1174          */
 1175         KASSERT(IN6_IS_ADDR_MULTICAST(mcaddr),
 1176             ("%s: not a multicast address", __func__));
 1177         if (IN6_IS_ADDR_MC_LINKLOCAL(mcaddr) ||
 1178             IN6_IS_ADDR_MC_INTFACELOCAL(mcaddr)) {
 1179                 KASSERT(mcaddr->s6_addr16[1] != 0,
 1180                     ("%s: scope zone ID not set", __func__));
 1181         }
 1182 #endif
 1183 
 1184         IN6_MULTI_LOCK_ASSERT();
 1185 
 1186         CTR4(KTR_MLD, "%s: join %s on %p(%s))", __func__,
 1187             ip6_sprintf(ip6tbuf, mcaddr), ifp, if_name(ifp));
 1188 
 1189         error = 0;
 1190         inm = NULL;
 1191 
 1192         /*
 1193          * If no imf was specified (i.e. kernel consumer),
 1194          * fake one up and assume it is an ASM join.
 1195          */
 1196         if (imf == NULL) {
 1197                 im6f_init(&timf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 1198                 imf = &timf;
 1199         }
 1200 
 1201         error = in6_mc_get(ifp, mcaddr, &inm);
 1202         if (error) {
 1203                 CTR1(KTR_MLD, "%s: in6_mc_get() failure", __func__);
 1204                 return (error);
 1205         }
 1206 
 1207         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1208         error = in6m_merge(inm, imf);
 1209         if (error) {
 1210                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1211                 goto out_in6m_release;
 1212         }
 1213 
 1214         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1215         error = mld_change_state(inm, delay);
 1216         if (error) {
 1217                 CTR1(KTR_MLD, "%s: failed to update source", __func__);
 1218                 goto out_in6m_release;
 1219         }
 1220 
 1221 out_in6m_release:
 1222         if (error) {
 1223                 CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1224                 in6m_release_locked(inm);
 1225         } else {
 1226                 *pinm = inm;
 1227         }
 1228 
 1229         return (error);
 1230 }
 1231 
 1232 /*
 1233  * Leave a multicast group; unlocked entry point.
 1234  */
 1235 int
 1236 in6_mc_leave(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1237 {
 1238         struct ifnet *ifp;
 1239         int error;
 1240 
 1241         ifp = inm->in6m_ifp;
 1242 
 1243         IN6_MULTI_LOCK();
 1244         error = in6_mc_leave_locked(inm, imf);
 1245         IN6_MULTI_UNLOCK();
 1246 
 1247         return (error);
 1248 }
 1249 
 1250 /*
 1251  * Leave a multicast group; real entry point.
 1252  * All source filters will be expunged.
 1253  *
 1254  * Only preserves atomicity at inm level.
 1255  *
 1256  * Holding the write lock for the INP which contains imf
 1257  * is highly advisable. We can't assert for it as imf does not
 1258  * contain a back-pointer to the owning inp.
 1259  *
 1260  * Note: This is not the same as in6m_release(*) as this function also
 1261  * makes a state change downcall into MLD.
 1262  */
 1263 int
 1264 in6_mc_leave_locked(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
 1265 {
 1266         struct in6_mfilter       timf;
 1267         int                      error;
 1268 #ifdef KTR
 1269         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1270 #endif
 1271 
 1272         error = 0;
 1273 
 1274         IN6_MULTI_LOCK_ASSERT();
 1275 
 1276         CTR5(KTR_MLD, "%s: leave inm %p, %s/%s, imf %p", __func__,
 1277             inm, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 1278             (in6m_is_ifp_detached(inm) ? "null" : if_name(inm->in6m_ifp)),
 1279             imf);
 1280 
 1281         /*
 1282          * If no imf was specified (i.e. kernel consumer),
 1283          * fake one up and assume it is an ASM join.
 1284          */
 1285         if (imf == NULL) {
 1286                 im6f_init(&timf, MCAST_EXCLUDE, MCAST_UNDEFINED);
 1287                 imf = &timf;
 1288         }
 1289 
 1290         /*
 1291          * Begin state merge transaction at MLD layer.
 1292          *
 1293          * As this particular invocation should not cause any memory
 1294          * to be allocated, and there is no opportunity to roll back
 1295          * the transaction, it MUST NOT fail.
 1296          */
 1297         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1298         error = in6m_merge(inm, imf);
 1299         KASSERT(error == 0, ("%s: failed to merge inm state", __func__));
 1300 
 1301         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1302         error = mld_change_state(inm, 0);
 1303         if (error)
 1304                 CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1305 
 1306         CTR2(KTR_MLD, "%s: dropping ref on %p", __func__, inm);
 1307         in6m_release_locked(inm);
 1308 
 1309         return (error);
 1310 }
 1311 
 1312 /*
 1313  * Block or unblock an ASM multicast source on an inpcb.
 1314  * This implements the delta-based API described in RFC 3678.
 1315  *
 1316  * The delta-based API applies only to exclusive-mode memberships.
 1317  * An MLD downcall will be performed.
 1318  *
 1319  * SMPng: NOTE: Must take Giant as a join may create a new ifma.
 1320  *
 1321  * Return 0 if successful, otherwise return an appropriate error code.
 1322  */
 1323 static int
 1324 in6p_block_unblock_source(struct inpcb *inp, struct sockopt *sopt)
 1325 {
 1326         struct group_source_req          gsr;
 1327         sockunion_t                     *gsa, *ssa;
 1328         struct ifnet                    *ifp;
 1329         struct in6_mfilter              *imf;
 1330         struct ip6_moptions             *imo;
 1331         struct in6_msource              *ims;
 1332         struct in6_multi                        *inm;
 1333         size_t                           idx;
 1334         uint16_t                         fmode;
 1335         int                              error, doblock;
 1336 #ifdef KTR
 1337         char                             ip6tbuf[INET6_ADDRSTRLEN];
 1338 #endif
 1339 
 1340         ifp = NULL;
 1341         error = 0;
 1342         doblock = 0;
 1343 
 1344         memset(&gsr, 0, sizeof(struct group_source_req));
 1345         gsa = (sockunion_t *)&gsr.gsr_group;
 1346         ssa = (sockunion_t *)&gsr.gsr_source;
 1347 
 1348         switch (sopt->sopt_name) {
 1349         case MCAST_BLOCK_SOURCE:
 1350         case MCAST_UNBLOCK_SOURCE:
 1351                 error = sooptcopyin(sopt, &gsr,
 1352                     sizeof(struct group_source_req),
 1353                     sizeof(struct group_source_req));
 1354                 if (error)
 1355                         return (error);
 1356 
 1357                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1358                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1359                         return (EINVAL);
 1360 
 1361                 if (ssa->sin6.sin6_family != AF_INET6 ||
 1362                     ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1363                         return (EINVAL);
 1364 
 1365                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1366                         return (EADDRNOTAVAIL);
 1367 
 1368                 ifp = ifnet_byindex(gsr.gsr_interface);
 1369 
 1370                 if (sopt->sopt_name == MCAST_BLOCK_SOURCE)
 1371                         doblock = 1;
 1372                 break;
 1373 
 1374         default:
 1375                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1376                     __func__, sopt->sopt_name);
 1377                 return (EOPNOTSUPP);
 1378                 break;
 1379         }
 1380 
 1381         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1382                 return (EINVAL);
 1383 
 1384         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1385 
 1386         /*
 1387          * Check if we are actually a member of this group.
 1388          */
 1389         imo = in6p_findmoptions(inp);
 1390         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1391         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1392                 error = EADDRNOTAVAIL;
 1393                 goto out_in6p_locked;
 1394         }
 1395 
 1396         KASSERT(imo->im6o_mfilters != NULL,
 1397             ("%s: im6o_mfilters not allocated", __func__));
 1398         imf = &imo->im6o_mfilters[idx];
 1399         inm = imo->im6o_membership[idx];
 1400 
 1401         /*
 1402          * Attempting to use the delta-based API on an
 1403          * non exclusive-mode membership is an error.
 1404          */
 1405         fmode = imf->im6f_st[0];
 1406         if (fmode != MCAST_EXCLUDE) {
 1407                 error = EINVAL;
 1408                 goto out_in6p_locked;
 1409         }
 1410 
 1411         /*
 1412          * Deal with error cases up-front:
 1413          *  Asked to block, but already blocked; or
 1414          *  Asked to unblock, but nothing to unblock.
 1415          * If adding a new block entry, allocate it.
 1416          */
 1417         ims = im6o_match_source(imo, idx, &ssa->sa);
 1418         if ((ims != NULL && doblock) || (ims == NULL && !doblock)) {
 1419                 CTR3(KTR_MLD, "%s: source %s %spresent", __func__,
 1420                     ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 1421                     doblock ? "" : "not ");
 1422                 error = EADDRNOTAVAIL;
 1423                 goto out_in6p_locked;
 1424         }
 1425 
 1426         INP_WLOCK_ASSERT(inp);
 1427 
 1428         /*
 1429          * Begin state merge transaction at socket layer.
 1430          */
 1431         if (doblock) {
 1432                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 1433                 ims = im6f_graft(imf, fmode, &ssa->sin6);
 1434                 if (ims == NULL)
 1435                         error = ENOMEM;
 1436         } else {
 1437                 CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 1438                 error = im6f_prune(imf, &ssa->sin6);
 1439         }
 1440 
 1441         if (error) {
 1442                 CTR1(KTR_MLD, "%s: merge imf state failed", __func__);
 1443                 goto out_im6f_rollback;
 1444         }
 1445 
 1446         /*
 1447          * Begin state merge transaction at MLD layer.
 1448          */
 1449         IN6_MULTI_LOCK();
 1450 
 1451         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 1452         error = in6m_merge(inm, imf);
 1453         if (error)
 1454                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 1455         else {
 1456                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 1457                 error = mld_change_state(inm, 0);
 1458                 if (error)
 1459                         CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 1460         }
 1461 
 1462         IN6_MULTI_UNLOCK();
 1463 
 1464 out_im6f_rollback:
 1465         if (error)
 1466                 im6f_rollback(imf);
 1467         else
 1468                 im6f_commit(imf);
 1469 
 1470         im6f_reap(imf);
 1471 
 1472 out_in6p_locked:
 1473         INP_WUNLOCK(inp);
 1474         return (error);
 1475 }
 1476 
 1477 /*
 1478  * Given an inpcb, return its multicast options structure pointer.  Accepts
 1479  * an unlocked inpcb pointer, but will return it locked.  May sleep.
 1480  *
 1481  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 1482  * SMPng: NOTE: Returns with the INP write lock held.
 1483  */
 1484 static struct ip6_moptions *
 1485 in6p_findmoptions(struct inpcb *inp)
 1486 {
 1487         struct ip6_moptions      *imo;
 1488         struct in6_multi                **immp;
 1489         struct in6_mfilter       *imfp;
 1490         size_t                    idx;
 1491 
 1492         INP_WLOCK(inp);
 1493         if (inp->in6p_moptions != NULL)
 1494                 return (inp->in6p_moptions);
 1495 
 1496         INP_WUNLOCK(inp);
 1497 
 1498         imo = malloc(sizeof(*imo), M_IP6MOPTS, M_WAITOK);
 1499         immp = malloc(sizeof(*immp) * IPV6_MIN_MEMBERSHIPS, M_IP6MOPTS,
 1500             M_WAITOK | M_ZERO);
 1501         imfp = malloc(sizeof(struct in6_mfilter) * IPV6_MIN_MEMBERSHIPS,
 1502             M_IN6MFILTER, M_WAITOK);
 1503 
 1504         imo->im6o_multicast_ifp = NULL;
 1505         imo->im6o_multicast_hlim = V_ip6_defmcasthlim;
 1506         imo->im6o_multicast_loop = in6_mcast_loop;
 1507         imo->im6o_num_memberships = 0;
 1508         imo->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS;
 1509         imo->im6o_membership = immp;
 1510 
 1511         /* Initialize per-group source filters. */
 1512         for (idx = 0; idx < IPV6_MIN_MEMBERSHIPS; idx++)
 1513                 im6f_init(&imfp[idx], MCAST_UNDEFINED, MCAST_EXCLUDE);
 1514         imo->im6o_mfilters = imfp;
 1515 
 1516         INP_WLOCK(inp);
 1517         if (inp->in6p_moptions != NULL) {
 1518                 free(imfp, M_IN6MFILTER);
 1519                 free(immp, M_IP6MOPTS);
 1520                 free(imo, M_IP6MOPTS);
 1521                 return (inp->in6p_moptions);
 1522         }
 1523         inp->in6p_moptions = imo;
 1524         return (imo);
 1525 }
 1526 
 1527 /*
 1528  * Discard the IPv6 multicast options (and source filters).
 1529  *
 1530  * SMPng: NOTE: assumes INP write lock is held.
 1531  */
 1532 void
 1533 ip6_freemoptions(struct ip6_moptions *imo)
 1534 {
 1535         struct in6_mfilter      *imf;
 1536         size_t                   idx, nmships;
 1537 
 1538         KASSERT(imo != NULL, ("%s: ip6_moptions is NULL", __func__));
 1539 
 1540         nmships = imo->im6o_num_memberships;
 1541         for (idx = 0; idx < nmships; ++idx) {
 1542                 imf = imo->im6o_mfilters ? &imo->im6o_mfilters[idx] : NULL;
 1543                 if (imf)
 1544                         im6f_leave(imf);
 1545                 /* XXX this will thrash the lock(s) */
 1546                 (void)in6_mc_leave(imo->im6o_membership[idx], imf);
 1547                 if (imf)
 1548                         im6f_purge(imf);
 1549         }
 1550 
 1551         if (imo->im6o_mfilters)
 1552                 free(imo->im6o_mfilters, M_IN6MFILTER);
 1553         free(imo->im6o_membership, M_IP6MOPTS);
 1554         free(imo, M_IP6MOPTS);
 1555 }
 1556 
 1557 /*
 1558  * Atomically get source filters on a socket for an IPv6 multicast group.
 1559  * Called with INP lock held; returns with lock released.
 1560  */
 1561 static int
 1562 in6p_get_source_filters(struct inpcb *inp, struct sockopt *sopt)
 1563 {
 1564         struct __msfilterreq     msfr;
 1565         sockunion_t             *gsa;
 1566         struct ifnet            *ifp;
 1567         struct ip6_moptions     *imo;
 1568         struct in6_mfilter      *imf;
 1569         struct ip6_msource      *ims;
 1570         struct in6_msource      *lims;
 1571         struct sockaddr_in6     *psin;
 1572         struct sockaddr_storage *ptss;
 1573         struct sockaddr_storage *tss;
 1574         int                      error;
 1575         size_t                   idx, nsrcs, ncsrcs;
 1576 
 1577         INP_WLOCK_ASSERT(inp);
 1578 
 1579         imo = inp->in6p_moptions;
 1580         KASSERT(imo != NULL, ("%s: null ip6_moptions", __func__));
 1581 
 1582         INP_WUNLOCK(inp);
 1583 
 1584         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 1585             sizeof(struct __msfilterreq));
 1586         if (error)
 1587                 return (error);
 1588 
 1589         if (msfr.msfr_group.ss_family != AF_INET6 ||
 1590             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 1591                 return (EINVAL);
 1592 
 1593         gsa = (sockunion_t *)&msfr.msfr_group;
 1594         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1595                 return (EINVAL);
 1596 
 1597         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 1598                 return (EADDRNOTAVAIL);
 1599         ifp = ifnet_byindex(msfr.msfr_ifindex);
 1600         if (ifp == NULL)
 1601                 return (EADDRNOTAVAIL);
 1602         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1603 
 1604         INP_WLOCK(inp);
 1605 
 1606         /*
 1607          * Lookup group on the socket.
 1608          */
 1609         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1610         if (idx == -1 || imo->im6o_mfilters == NULL) {
 1611                 INP_WUNLOCK(inp);
 1612                 return (EADDRNOTAVAIL);
 1613         }
 1614         imf = &imo->im6o_mfilters[idx];
 1615 
 1616         /*
 1617          * Ignore memberships which are in limbo.
 1618          */
 1619         if (imf->im6f_st[1] == MCAST_UNDEFINED) {
 1620                 INP_WUNLOCK(inp);
 1621                 return (EAGAIN);
 1622         }
 1623         msfr.msfr_fmode = imf->im6f_st[1];
 1624 
 1625         /*
 1626          * If the user specified a buffer, copy out the source filter
 1627          * entries to userland gracefully.
 1628          * We only copy out the number of entries which userland
 1629          * has asked for, but we always tell userland how big the
 1630          * buffer really needs to be.
 1631          */
 1632         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 1633                 msfr.msfr_nsrcs = in6_mcast_maxsocksrc;
 1634         tss = NULL;
 1635         if (msfr.msfr_srcs != NULL && msfr.msfr_nsrcs > 0) {
 1636                 tss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 1637                     M_TEMP, M_NOWAIT | M_ZERO);
 1638                 if (tss == NULL) {
 1639                         INP_WUNLOCK(inp);
 1640                         return (ENOBUFS);
 1641                 }
 1642         }
 1643 
 1644         /*
 1645          * Count number of sources in-mode at t0.
 1646          * If buffer space exists and remains, copy out source entries.
 1647          */
 1648         nsrcs = msfr.msfr_nsrcs;
 1649         ncsrcs = 0;
 1650         ptss = tss;
 1651         RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
 1652                 lims = (struct in6_msource *)ims;
 1653                 if (lims->im6sl_st[0] == MCAST_UNDEFINED ||
 1654                     lims->im6sl_st[0] != imf->im6f_st[0])
 1655                         continue;
 1656                 ++ncsrcs;
 1657                 if (tss != NULL && nsrcs > 0) {
 1658                         psin = (struct sockaddr_in6 *)ptss;
 1659                         psin->sin6_family = AF_INET6;
 1660                         psin->sin6_len = sizeof(struct sockaddr_in6);
 1661                         psin->sin6_addr = lims->im6s_addr;
 1662                         psin->sin6_port = 0;
 1663                         --nsrcs;
 1664                         ++ptss;
 1665                 }
 1666         }
 1667 
 1668         INP_WUNLOCK(inp);
 1669 
 1670         if (tss != NULL) {
 1671                 error = copyout(tss, msfr.msfr_srcs,
 1672                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 1673                 free(tss, M_TEMP);
 1674                 if (error)
 1675                         return (error);
 1676         }
 1677 
 1678         msfr.msfr_nsrcs = ncsrcs;
 1679         error = sooptcopyout(sopt, &msfr, sizeof(struct __msfilterreq));
 1680 
 1681         return (error);
 1682 }
 1683 
 1684 /*
 1685  * Return the IP multicast options in response to user getsockopt().
 1686  */
 1687 int
 1688 ip6_getmoptions(struct inpcb *inp, struct sockopt *sopt)
 1689 {
 1690         struct ip6_moptions     *im6o;
 1691         int                      error;
 1692         u_int                    optval;
 1693 
 1694         INP_WLOCK(inp);
 1695         im6o = inp->in6p_moptions;
 1696         /*
 1697          * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 1698          * or is a divert socket, reject it.
 1699          */
 1700         if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
 1701             (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
 1702             inp->inp_socket->so_proto->pr_type != SOCK_DGRAM)) {
 1703                 INP_WUNLOCK(inp);
 1704                 return (EOPNOTSUPP);
 1705         }
 1706 
 1707         error = 0;
 1708         switch (sopt->sopt_name) {
 1709         case IPV6_MULTICAST_IF:
 1710                 if (im6o == NULL || im6o->im6o_multicast_ifp == NULL) {
 1711                         optval = 0;
 1712                 } else {
 1713                         optval = im6o->im6o_multicast_ifp->if_index;
 1714                 }
 1715                 INP_WUNLOCK(inp);
 1716                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1717                 break;
 1718 
 1719         case IPV6_MULTICAST_HOPS:
 1720                 if (im6o == NULL)
 1721                         optval = V_ip6_defmcasthlim;
 1722                 else
 1723                         optval = im6o->im6o_multicast_hlim;
 1724                 INP_WUNLOCK(inp);
 1725                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1726                 break;
 1727 
 1728         case IPV6_MULTICAST_LOOP:
 1729                 if (im6o == NULL)
 1730                         optval = in6_mcast_loop; /* XXX VIMAGE */
 1731                 else
 1732                         optval = im6o->im6o_multicast_loop;
 1733                 INP_WUNLOCK(inp);
 1734                 error = sooptcopyout(sopt, &optval, sizeof(u_int));
 1735                 break;
 1736 
 1737         case IPV6_MSFILTER:
 1738                 if (im6o == NULL) {
 1739                         error = EADDRNOTAVAIL;
 1740                         INP_WUNLOCK(inp);
 1741                 } else {
 1742                         error = in6p_get_source_filters(inp, sopt);
 1743                 }
 1744                 break;
 1745 
 1746         default:
 1747                 INP_WUNLOCK(inp);
 1748                 error = ENOPROTOOPT;
 1749                 break;
 1750         }
 1751 
 1752         INP_UNLOCK_ASSERT(inp);
 1753 
 1754         return (error);
 1755 }
 1756 
 1757 /*
 1758  * Look up the ifnet to use for a multicast group membership,
 1759  * given the address of an IPv6 group.
 1760  *
 1761  * This routine exists to support legacy IPv6 multicast applications.
 1762  *
 1763  * If inp is non-NULL, use this socket's current FIB number for any
 1764  * required FIB lookup. Look up the group address in the unicast FIB,
 1765  * and use its ifp; usually, this points to the default next-hop.
 1766  * If the FIB lookup fails, return NULL.
 1767  *
 1768  * FUTURE: Support multiple forwarding tables for IPv6.
 1769  *
 1770  * Returns NULL if no ifp could be found.
 1771  */
 1772 static struct ifnet *
 1773 in6p_lookup_mcast_ifp(const struct inpcb *in6p,
 1774     const struct sockaddr_in6 *gsin6)
 1775 {
 1776         struct nhop6_basic      nh6;
 1777         struct in6_addr         dst;
 1778         uint32_t                scopeid;
 1779         uint32_t                fibnum;
 1780 
 1781         KASSERT(in6p->inp_vflag & INP_IPV6,
 1782             ("%s: not INP_IPV6 inpcb", __func__));
 1783         KASSERT(gsin6->sin6_family == AF_INET6,
 1784             ("%s: not AF_INET6 group", __func__));
 1785 
 1786         in6_splitscope(&gsin6->sin6_addr, &dst, &scopeid);
 1787         fibnum = in6p ? in6p->inp_inc.inc_fibnum : RT_DEFAULT_FIB;
 1788         if (fib6_lookup_nh_basic(fibnum, &dst, scopeid, 0, 0, &nh6) != 0)
 1789                 return (NULL);
 1790 
 1791         return (nh6.nh_ifp);
 1792 }
 1793 
 1794 /*
 1795  * Join an IPv6 multicast group, possibly with a source.
 1796  *
 1797  * FIXME: The KAME use of the unspecified address (::)
 1798  * to join *all* multicast groups is currently unsupported.
 1799  */
 1800 static int
 1801 in6p_join_group(struct inpcb *inp, struct sockopt *sopt)
 1802 {
 1803         struct group_source_req          gsr;
 1804         sockunion_t                     *gsa, *ssa;
 1805         struct ifnet                    *ifp;
 1806         struct in6_mfilter              *imf;
 1807         struct ip6_moptions             *imo;
 1808         struct in6_multi                *inm;
 1809         struct in6_msource              *lims;
 1810         size_t                           idx;
 1811         int                              error, is_new;
 1812 
 1813         ifp = NULL;
 1814         imf = NULL;
 1815         lims = NULL;
 1816         error = 0;
 1817         is_new = 0;
 1818 
 1819         memset(&gsr, 0, sizeof(struct group_source_req));
 1820         gsa = (sockunion_t *)&gsr.gsr_group;
 1821         gsa->ss.ss_family = AF_UNSPEC;
 1822         ssa = (sockunion_t *)&gsr.gsr_source;
 1823         ssa->ss.ss_family = AF_UNSPEC;
 1824 
 1825         /*
 1826          * Chew everything into struct group_source_req.
 1827          * Overwrite the port field if present, as the sockaddr
 1828          * being copied in may be matched with a binary comparison.
 1829          * Ignore passed-in scope ID.
 1830          */
 1831         switch (sopt->sopt_name) {
 1832         case IPV6_JOIN_GROUP: {
 1833                 struct ipv6_mreq mreq;
 1834 
 1835                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 1836                     sizeof(struct ipv6_mreq));
 1837                 if (error)
 1838                         return (error);
 1839 
 1840                 gsa->sin6.sin6_family = AF_INET6;
 1841                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 1842                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 1843 
 1844                 if (mreq.ipv6mr_interface == 0) {
 1845                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 1846                 } else {
 1847                         if (V_if_index < mreq.ipv6mr_interface)
 1848                                 return (EADDRNOTAVAIL);
 1849                         ifp = ifnet_byindex(mreq.ipv6mr_interface);
 1850                 }
 1851                 CTR3(KTR_MLD, "%s: ipv6mr_interface = %d, ifp = %p",
 1852                     __func__, mreq.ipv6mr_interface, ifp);
 1853         } break;
 1854 
 1855         case MCAST_JOIN_GROUP:
 1856         case MCAST_JOIN_SOURCE_GROUP:
 1857                 if (sopt->sopt_name == MCAST_JOIN_GROUP) {
 1858                         error = sooptcopyin(sopt, &gsr,
 1859                             sizeof(struct group_req),
 1860                             sizeof(struct group_req));
 1861                 } else if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1862                         error = sooptcopyin(sopt, &gsr,
 1863                             sizeof(struct group_source_req),
 1864                             sizeof(struct group_source_req));
 1865                 }
 1866                 if (error)
 1867                         return (error);
 1868 
 1869                 if (gsa->sin6.sin6_family != AF_INET6 ||
 1870                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1871                         return (EINVAL);
 1872 
 1873                 if (sopt->sopt_name == MCAST_JOIN_SOURCE_GROUP) {
 1874                         if (ssa->sin6.sin6_family != AF_INET6 ||
 1875                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 1876                                 return (EINVAL);
 1877                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 1878                                 return (EINVAL);
 1879                         /*
 1880                          * TODO: Validate embedded scope ID in source
 1881                          * list entry against passed-in ifp, if and only
 1882                          * if source list filter entry is iface or node local.
 1883                          */
 1884                         in6_clearscope(&ssa->sin6.sin6_addr);
 1885                         ssa->sin6.sin6_port = 0;
 1886                         ssa->sin6.sin6_scope_id = 0;
 1887                 }
 1888 
 1889                 if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 1890                         return (EADDRNOTAVAIL);
 1891                 ifp = ifnet_byindex(gsr.gsr_interface);
 1892                 break;
 1893 
 1894         default:
 1895                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 1896                     __func__, sopt->sopt_name);
 1897                 return (EOPNOTSUPP);
 1898                 break;
 1899         }
 1900 
 1901         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 1902                 return (EINVAL);
 1903 
 1904         if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
 1905                 return (EADDRNOTAVAIL);
 1906 
 1907         gsa->sin6.sin6_port = 0;
 1908         gsa->sin6.sin6_scope_id = 0;
 1909 
 1910         /*
 1911          * Always set the scope zone ID on memberships created from userland.
 1912          * Use the passed-in ifp to do this.
 1913          * XXX The in6_setscope() return value is meaningless.
 1914          * XXX SCOPE6_LOCK() is taken by in6_setscope().
 1915          */
 1916         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 1917 
 1918         imo = in6p_findmoptions(inp);
 1919         idx = im6o_match_group(imo, ifp, &gsa->sa);
 1920         if (idx == -1) {
 1921                 is_new = 1;
 1922         } else {
 1923                 inm = imo->im6o_membership[idx];
 1924                 imf = &imo->im6o_mfilters[idx];
 1925                 if (ssa->ss.ss_family != AF_UNSPEC) {
 1926                         /*
 1927                          * MCAST_JOIN_SOURCE_GROUP on an exclusive membership
 1928                          * is an error. On an existing inclusive membership,
 1929                          * it just adds the source to the filter list.
 1930                          */
 1931                         if (imf->im6f_st[1] != MCAST_INCLUDE) {
 1932                                 error = EINVAL;
 1933                                 goto out_in6p_locked;
 1934                         }
 1935                         /*
 1936                          * Throw out duplicates.
 1937                          *
 1938                          * XXX FIXME: This makes a naive assumption that
 1939                          * even if entries exist for *ssa in this imf,
 1940                          * they will be rejected as dupes, even if they
 1941                          * are not valid in the current mode (in-mode).
 1942                          *
 1943                          * in6_msource is transactioned just as for anything
 1944                          * else in SSM -- but note naive use of in6m_graft()
 1945                          * below for allocating new filter entries.
 1946                          *
 1947                          * This is only an issue if someone mixes the
 1948                          * full-state SSM API with the delta-based API,
 1949                          * which is discouraged in the relevant RFCs.
 1950                          */
 1951                         lims = im6o_match_source(imo, idx, &ssa->sa);
 1952                         if (lims != NULL /*&&
 1953                             lims->im6sl_st[1] == MCAST_INCLUDE*/) {
 1954                                 error = EADDRNOTAVAIL;
 1955                                 goto out_in6p_locked;
 1956                         }
 1957                 } else {
 1958                         /*
 1959                          * MCAST_JOIN_GROUP alone, on any existing membership,
 1960                          * is rejected, to stop the same inpcb tying up
 1961                          * multiple refs to the in_multi.
 1962                          * On an existing inclusive membership, this is also
 1963                          * an error; if you want to change filter mode,
 1964                          * you must use the userland API setsourcefilter().
 1965                          * XXX We don't reject this for imf in UNDEFINED
 1966                          * state at t1, because allocation of a filter
 1967                          * is atomic with allocation of a membership.
 1968                          */
 1969                         error = EINVAL;
 1970                         goto out_in6p_locked;
 1971                 }
 1972         }
 1973 
 1974         /*
 1975          * Begin state merge transaction at socket layer.
 1976          */
 1977         INP_WLOCK_ASSERT(inp);
 1978 
 1979         if (is_new) {
 1980                 if (imo->im6o_num_memberships == imo->im6o_max_memberships) {
 1981                         error = im6o_grow(imo);
 1982                         if (error)
 1983                                 goto out_in6p_locked;
 1984                 }
 1985                 /*
 1986                  * Allocate the new slot upfront so we can deal with
 1987                  * grafting the new source filter in same code path
 1988                  * as for join-source on existing membership.
 1989                  */
 1990                 idx = imo->im6o_num_memberships;
 1991                 imo->im6o_membership[idx] = NULL;
 1992                 imo->im6o_num_memberships++;
 1993                 KASSERT(imo->im6o_mfilters != NULL,
 1994                     ("%s: im6f_mfilters vector was not allocated", __func__));
 1995                 imf = &imo->im6o_mfilters[idx];
 1996                 KASSERT(RB_EMPTY(&imf->im6f_sources),
 1997                     ("%s: im6f_sources not empty", __func__));
 1998         }
 1999 
 2000         /*
 2001          * Graft new source into filter list for this inpcb's
 2002          * membership of the group. The in6_multi may not have
 2003          * been allocated yet if this is a new membership, however,
 2004          * the in_mfilter slot will be allocated and must be initialized.
 2005          *
 2006          * Note: Grafting of exclusive mode filters doesn't happen
 2007          * in this path.
 2008          * XXX: Should check for non-NULL lims (node exists but may
 2009          * not be in-mode) for interop with full-state API.
 2010          */
 2011         if (ssa->ss.ss_family != AF_UNSPEC) {
 2012                 /* Membership starts in IN mode */
 2013                 if (is_new) {
 2014                         CTR1(KTR_MLD, "%s: new join w/source", __func__);
 2015                         im6f_init(imf, MCAST_UNDEFINED, MCAST_INCLUDE);
 2016                 } else {
 2017                         CTR2(KTR_MLD, "%s: %s source", __func__, "allow");
 2018                 }
 2019                 lims = im6f_graft(imf, MCAST_INCLUDE, &ssa->sin6);
 2020                 if (lims == NULL) {
 2021                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2022                             __func__);
 2023                         error = ENOMEM;
 2024                         goto out_im6o_free;
 2025                 }
 2026         } else {
 2027                 /* No address specified; Membership starts in EX mode */
 2028                 if (is_new) {
 2029                         CTR1(KTR_MLD, "%s: new join w/o source", __func__);
 2030                         im6f_init(imf, MCAST_UNDEFINED, MCAST_EXCLUDE);
 2031                 }
 2032         }
 2033 
 2034         /*
 2035          * Begin state merge transaction at MLD layer.
 2036          */
 2037         IN6_MULTI_LOCK();
 2038 
 2039         if (is_new) {
 2040                 error = in6_mc_join_locked(ifp, &gsa->sin6.sin6_addr, imf,
 2041                     &inm, 0);
 2042                 if (error) {
 2043                         IN6_MULTI_UNLOCK();
 2044                         goto out_im6o_free;
 2045                 }
 2046                 imo->im6o_membership[idx] = inm;
 2047         } else {
 2048                 CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2049                 error = in6m_merge(inm, imf);
 2050                 if (error)
 2051                         CTR1(KTR_MLD, "%s: failed to merge inm state",
 2052                             __func__);
 2053                 else {
 2054                         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2055                         error = mld_change_state(inm, 0);
 2056                         if (error)
 2057                                 CTR1(KTR_MLD, "%s: failed mld downcall",
 2058                                     __func__);
 2059                 }
 2060         }
 2061 
 2062         IN6_MULTI_UNLOCK();
 2063         INP_WLOCK_ASSERT(inp);
 2064         if (error) {
 2065                 im6f_rollback(imf);
 2066                 if (is_new)
 2067                         im6f_purge(imf);
 2068                 else
 2069                         im6f_reap(imf);
 2070         } else {
 2071                 im6f_commit(imf);
 2072         }
 2073 
 2074 out_im6o_free:
 2075         if (error && is_new) {
 2076                 imo->im6o_membership[idx] = NULL;
 2077                 --imo->im6o_num_memberships;
 2078         }
 2079 
 2080 out_in6p_locked:
 2081         INP_WUNLOCK(inp);
 2082         return (error);
 2083 }
 2084 
 2085 /*
 2086  * Leave an IPv6 multicast group on an inpcb, possibly with a source.
 2087  */
 2088 static int
 2089 in6p_leave_group(struct inpcb *inp, struct sockopt *sopt)
 2090 {
 2091         struct ipv6_mreq                 mreq;
 2092         struct group_source_req          gsr;
 2093         sockunion_t                     *gsa, *ssa;
 2094         struct ifnet                    *ifp;
 2095         struct in6_mfilter              *imf;
 2096         struct ip6_moptions             *imo;
 2097         struct in6_msource              *ims;
 2098         struct in6_multi                *inm;
 2099         uint32_t                         ifindex;
 2100         size_t                           idx;
 2101         int                              error, is_final;
 2102 #ifdef KTR
 2103         char                             ip6tbuf[INET6_ADDRSTRLEN];
 2104 #endif
 2105 
 2106         ifp = NULL;
 2107         ifindex = 0;
 2108         error = 0;
 2109         is_final = 1;
 2110 
 2111         memset(&gsr, 0, sizeof(struct group_source_req));
 2112         gsa = (sockunion_t *)&gsr.gsr_group;
 2113         gsa->ss.ss_family = AF_UNSPEC;
 2114         ssa = (sockunion_t *)&gsr.gsr_source;
 2115         ssa->ss.ss_family = AF_UNSPEC;
 2116 
 2117         /*
 2118          * Chew everything passed in up into a struct group_source_req
 2119          * as that is easier to process.
 2120          * Note: Any embedded scope ID in the multicast group passed
 2121          * in by userland is ignored, the interface index is the recommended
 2122          * mechanism to specify an interface; see below.
 2123          */
 2124         switch (sopt->sopt_name) {
 2125         case IPV6_LEAVE_GROUP:
 2126                 error = sooptcopyin(sopt, &mreq, sizeof(struct ipv6_mreq),
 2127                     sizeof(struct ipv6_mreq));
 2128                 if (error)
 2129                         return (error);
 2130                 gsa->sin6.sin6_family = AF_INET6;
 2131                 gsa->sin6.sin6_len = sizeof(struct sockaddr_in6);
 2132                 gsa->sin6.sin6_addr = mreq.ipv6mr_multiaddr;
 2133                 gsa->sin6.sin6_port = 0;
 2134                 gsa->sin6.sin6_scope_id = 0;
 2135                 ifindex = mreq.ipv6mr_interface;
 2136                 break;
 2137 
 2138         case MCAST_LEAVE_GROUP:
 2139         case MCAST_LEAVE_SOURCE_GROUP:
 2140                 if (sopt->sopt_name == MCAST_LEAVE_GROUP) {
 2141                         error = sooptcopyin(sopt, &gsr,
 2142                             sizeof(struct group_req),
 2143                             sizeof(struct group_req));
 2144                 } else if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2145                         error = sooptcopyin(sopt, &gsr,
 2146                             sizeof(struct group_source_req),
 2147                             sizeof(struct group_source_req));
 2148                 }
 2149                 if (error)
 2150                         return (error);
 2151 
 2152                 if (gsa->sin6.sin6_family != AF_INET6 ||
 2153                     gsa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2154                         return (EINVAL);
 2155                 if (sopt->sopt_name == MCAST_LEAVE_SOURCE_GROUP) {
 2156                         if (ssa->sin6.sin6_family != AF_INET6 ||
 2157                             ssa->sin6.sin6_len != sizeof(struct sockaddr_in6))
 2158                                 return (EINVAL);
 2159                         if (IN6_IS_ADDR_MULTICAST(&ssa->sin6.sin6_addr))
 2160                                 return (EINVAL);
 2161                         /*
 2162                          * TODO: Validate embedded scope ID in source
 2163                          * list entry against passed-in ifp, if and only
 2164                          * if source list filter entry is iface or node local.
 2165                          */
 2166                         in6_clearscope(&ssa->sin6.sin6_addr);
 2167                 }
 2168                 gsa->sin6.sin6_port = 0;
 2169                 gsa->sin6.sin6_scope_id = 0;
 2170                 ifindex = gsr.gsr_interface;
 2171                 break;
 2172 
 2173         default:
 2174                 CTR2(KTR_MLD, "%s: unknown sopt_name %d",
 2175                     __func__, sopt->sopt_name);
 2176                 return (EOPNOTSUPP);
 2177                 break;
 2178         }
 2179 
 2180         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2181                 return (EINVAL);
 2182 
 2183         /*
 2184          * Validate interface index if provided. If no interface index
 2185          * was provided separately, attempt to look the membership up
 2186          * from the default scope as a last resort to disambiguate
 2187          * the membership we are being asked to leave.
 2188          * XXX SCOPE6 lock potentially taken here.
 2189          */
 2190         if (ifindex != 0) {
 2191                 if (V_if_index < ifindex)
 2192                         return (EADDRNOTAVAIL);
 2193                 ifp = ifnet_byindex(ifindex);
 2194                 if (ifp == NULL)
 2195                         return (EADDRNOTAVAIL);
 2196                 (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2197         } else {
 2198                 error = sa6_embedscope(&gsa->sin6, V_ip6_use_defzone);
 2199                 if (error)
 2200                         return (EADDRNOTAVAIL);
 2201                 /*
 2202                  * Some badly behaved applications don't pass an ifindex
 2203                  * or a scope ID, which is an API violation. In this case,
 2204                  * perform a lookup as per a v6 join.
 2205                  *
 2206                  * XXX For now, stomp on zone ID for the corner case.
 2207                  * This is not the 'KAME way', but we need to see the ifp
 2208                  * directly until such time as this implementation is
 2209                  * refactored, assuming the scope IDs are the way to go.
 2210                  */
 2211                 ifindex = ntohs(gsa->sin6.sin6_addr.s6_addr16[1]);
 2212                 if (ifindex == 0) {
 2213                         CTR2(KTR_MLD, "%s: warning: no ifindex, looking up "
 2214                             "ifp for group %s.", __func__,
 2215                             ip6_sprintf(ip6tbuf, &gsa->sin6.sin6_addr));
 2216                         ifp = in6p_lookup_mcast_ifp(inp, &gsa->sin6);
 2217                 } else {
 2218                         ifp = ifnet_byindex(ifindex);
 2219                 }
 2220                 if (ifp == NULL)
 2221                         return (EADDRNOTAVAIL);
 2222         }
 2223 
 2224         CTR2(KTR_MLD, "%s: ifp = %p", __func__, ifp);
 2225         KASSERT(ifp != NULL, ("%s: ifp did not resolve", __func__));
 2226 
 2227         /*
 2228          * Find the membership in the membership array.
 2229          */
 2230         imo = in6p_findmoptions(inp);
 2231         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2232         if (idx == -1) {
 2233                 error = EADDRNOTAVAIL;
 2234                 goto out_in6p_locked;
 2235         }
 2236         inm = imo->im6o_membership[idx];
 2237         imf = &imo->im6o_mfilters[idx];
 2238 
 2239         if (ssa->ss.ss_family != AF_UNSPEC)
 2240                 is_final = 0;
 2241 
 2242         /*
 2243          * Begin state merge transaction at socket layer.
 2244          */
 2245         INP_WLOCK_ASSERT(inp);
 2246 
 2247         /*
 2248          * If we were instructed only to leave a given source, do so.
 2249          * MCAST_LEAVE_SOURCE_GROUP is only valid for inclusive memberships.
 2250          */
 2251         if (is_final) {
 2252                 im6f_leave(imf);
 2253         } else {
 2254                 if (imf->im6f_st[0] == MCAST_EXCLUDE) {
 2255                         error = EADDRNOTAVAIL;
 2256                         goto out_in6p_locked;
 2257                 }
 2258                 ims = im6o_match_source(imo, idx, &ssa->sa);
 2259                 if (ims == NULL) {
 2260                         CTR3(KTR_MLD, "%s: source %p %spresent", __func__,
 2261                             ip6_sprintf(ip6tbuf, &ssa->sin6.sin6_addr),
 2262                             "not ");
 2263                         error = EADDRNOTAVAIL;
 2264                         goto out_in6p_locked;
 2265                 }
 2266                 CTR2(KTR_MLD, "%s: %s source", __func__, "block");
 2267                 error = im6f_prune(imf, &ssa->sin6);
 2268                 if (error) {
 2269                         CTR1(KTR_MLD, "%s: merge imf state failed",
 2270                             __func__);
 2271                         goto out_in6p_locked;
 2272                 }
 2273         }
 2274 
 2275         /*
 2276          * Begin state merge transaction at MLD layer.
 2277          */
 2278         IN6_MULTI_LOCK();
 2279 
 2280         if (is_final) {
 2281                 /*
 2282                  * Give up the multicast address record to which
 2283                  * the membership points.
 2284                  */
 2285                 (void)in6_mc_leave_locked(inm, imf);
 2286         } else {
 2287                 CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2288                 error = in6m_merge(inm, imf);
 2289                 if (error)
 2290                         CTR1(KTR_MLD, "%s: failed to merge inm state",
 2291                             __func__);
 2292                 else {
 2293                         CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2294                         error = mld_change_state(inm, 0);
 2295                         if (error)
 2296                                 CTR1(KTR_MLD, "%s: failed mld downcall",
 2297                                     __func__);
 2298                 }
 2299         }
 2300 
 2301         IN6_MULTI_UNLOCK();
 2302 
 2303         if (error)
 2304                 im6f_rollback(imf);
 2305         else
 2306                 im6f_commit(imf);
 2307 
 2308         im6f_reap(imf);
 2309 
 2310         if (is_final) {
 2311                 /* Remove the gap in the membership array. */
 2312                 for (++idx; idx < imo->im6o_num_memberships; ++idx) {
 2313                         imo->im6o_membership[idx-1] = imo->im6o_membership[idx];
 2314                         imo->im6o_mfilters[idx-1] = imo->im6o_mfilters[idx];
 2315                 }
 2316                 imo->im6o_num_memberships--;
 2317         }
 2318 
 2319 out_in6p_locked:
 2320         INP_WUNLOCK(inp);
 2321         return (error);
 2322 }
 2323 
 2324 /*
 2325  * Select the interface for transmitting IPv6 multicast datagrams.
 2326  *
 2327  * Either an instance of struct in6_addr or an instance of struct ipv6_mreqn
 2328  * may be passed to this socket option. An address of in6addr_any or an
 2329  * interface index of 0 is used to remove a previous selection.
 2330  * When no interface is selected, one is chosen for every send.
 2331  */
 2332 static int
 2333 in6p_set_multicast_if(struct inpcb *inp, struct sockopt *sopt)
 2334 {
 2335         struct ifnet            *ifp;
 2336         struct ip6_moptions     *imo;
 2337         u_int                    ifindex;
 2338         int                      error;
 2339 
 2340         if (sopt->sopt_valsize != sizeof(u_int))
 2341                 return (EINVAL);
 2342 
 2343         error = sooptcopyin(sopt, &ifindex, sizeof(u_int), sizeof(u_int));
 2344         if (error)
 2345                 return (error);
 2346         if (V_if_index < ifindex)
 2347                 return (EINVAL);
 2348         if (ifindex == 0)
 2349                 ifp = NULL;
 2350         else {
 2351                 ifp = ifnet_byindex(ifindex);
 2352                 if (ifp == NULL)
 2353                         return (EINVAL);
 2354                 if ((ifp->if_flags & IFF_MULTICAST) == 0)
 2355                         return (EADDRNOTAVAIL);
 2356         }
 2357         imo = in6p_findmoptions(inp);
 2358         imo->im6o_multicast_ifp = ifp;
 2359         INP_WUNLOCK(inp);
 2360 
 2361         return (0);
 2362 }
 2363 
 2364 /*
 2365  * Atomically set source filters on a socket for an IPv6 multicast group.
 2366  *
 2367  * SMPng: NOTE: Potentially calls malloc(M_WAITOK) with Giant held.
 2368  */
 2369 static int
 2370 in6p_set_source_filters(struct inpcb *inp, struct sockopt *sopt)
 2371 {
 2372         struct __msfilterreq     msfr;
 2373         sockunion_t             *gsa;
 2374         struct ifnet            *ifp;
 2375         struct in6_mfilter      *imf;
 2376         struct ip6_moptions     *imo;
 2377         struct in6_multi                *inm;
 2378         size_t                   idx;
 2379         int                      error;
 2380 
 2381         error = sooptcopyin(sopt, &msfr, sizeof(struct __msfilterreq),
 2382             sizeof(struct __msfilterreq));
 2383         if (error)
 2384                 return (error);
 2385 
 2386         if (msfr.msfr_nsrcs > in6_mcast_maxsocksrc)
 2387                 return (ENOBUFS);
 2388 
 2389         if (msfr.msfr_fmode != MCAST_EXCLUDE &&
 2390             msfr.msfr_fmode != MCAST_INCLUDE)
 2391                 return (EINVAL);
 2392 
 2393         if (msfr.msfr_group.ss_family != AF_INET6 ||
 2394             msfr.msfr_group.ss_len != sizeof(struct sockaddr_in6))
 2395                 return (EINVAL);
 2396 
 2397         gsa = (sockunion_t *)&msfr.msfr_group;
 2398         if (!IN6_IS_ADDR_MULTICAST(&gsa->sin6.sin6_addr))
 2399                 return (EINVAL);
 2400 
 2401         gsa->sin6.sin6_port = 0;        /* ignore port */
 2402 
 2403         if (msfr.msfr_ifindex == 0 || V_if_index < msfr.msfr_ifindex)
 2404                 return (EADDRNOTAVAIL);
 2405         ifp = ifnet_byindex(msfr.msfr_ifindex);
 2406         if (ifp == NULL)
 2407                 return (EADDRNOTAVAIL);
 2408         (void)in6_setscope(&gsa->sin6.sin6_addr, ifp, NULL);
 2409 
 2410         /*
 2411          * Take the INP write lock.
 2412          * Check if this socket is a member of this group.
 2413          */
 2414         imo = in6p_findmoptions(inp);
 2415         idx = im6o_match_group(imo, ifp, &gsa->sa);
 2416         if (idx == -1 || imo->im6o_mfilters == NULL) {
 2417                 error = EADDRNOTAVAIL;
 2418                 goto out_in6p_locked;
 2419         }
 2420         inm = imo->im6o_membership[idx];
 2421         imf = &imo->im6o_mfilters[idx];
 2422 
 2423         /*
 2424          * Begin state merge transaction at socket layer.
 2425          */
 2426         INP_WLOCK_ASSERT(inp);
 2427 
 2428         imf->im6f_st[1] = msfr.msfr_fmode;
 2429 
 2430         /*
 2431          * Apply any new source filters, if present.
 2432          * Make a copy of the user-space source vector so
 2433          * that we may copy them with a single copyin. This
 2434          * allows us to deal with page faults up-front.
 2435          */
 2436         if (msfr.msfr_nsrcs > 0) {
 2437                 struct in6_msource      *lims;
 2438                 struct sockaddr_in6     *psin;
 2439                 struct sockaddr_storage *kss, *pkss;
 2440                 int                      i;
 2441 
 2442                 INP_WUNLOCK(inp);
 2443  
 2444                 CTR2(KTR_MLD, "%s: loading %lu source list entries",
 2445                     __func__, (unsigned long)msfr.msfr_nsrcs);
 2446                 kss = malloc(sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs,
 2447                     M_TEMP, M_WAITOK);
 2448                 error = copyin(msfr.msfr_srcs, kss,
 2449                     sizeof(struct sockaddr_storage) * msfr.msfr_nsrcs);
 2450                 if (error) {
 2451                         free(kss, M_TEMP);
 2452                         return (error);
 2453                 }
 2454 
 2455                 INP_WLOCK(inp);
 2456 
 2457                 /*
 2458                  * Mark all source filters as UNDEFINED at t1.
 2459                  * Restore new group filter mode, as im6f_leave()
 2460                  * will set it to INCLUDE.
 2461                  */
 2462                 im6f_leave(imf);
 2463                 imf->im6f_st[1] = msfr.msfr_fmode;
 2464 
 2465                 /*
 2466                  * Update socket layer filters at t1, lazy-allocating
 2467                  * new entries. This saves a bunch of memory at the
 2468                  * cost of one RB_FIND() per source entry; duplicate
 2469                  * entries in the msfr_nsrcs vector are ignored.
 2470                  * If we encounter an error, rollback transaction.
 2471                  *
 2472                  * XXX This too could be replaced with a set-symmetric
 2473                  * difference like loop to avoid walking from root
 2474                  * every time, as the key space is common.
 2475                  */
 2476                 for (i = 0, pkss = kss; i < msfr.msfr_nsrcs; i++, pkss++) {
 2477                         psin = (struct sockaddr_in6 *)pkss;
 2478                         if (psin->sin6_family != AF_INET6) {
 2479                                 error = EAFNOSUPPORT;
 2480                                 break;
 2481                         }
 2482                         if (psin->sin6_len != sizeof(struct sockaddr_in6)) {
 2483                                 error = EINVAL;
 2484                                 break;
 2485                         }
 2486                         if (IN6_IS_ADDR_MULTICAST(&psin->sin6_addr)) {
 2487                                 error = EINVAL;
 2488                                 break;
 2489                         }
 2490                         /*
 2491                          * TODO: Validate embedded scope ID in source
 2492                          * list entry against passed-in ifp, if and only
 2493                          * if source list filter entry is iface or node local.
 2494                          */
 2495                         in6_clearscope(&psin->sin6_addr);
 2496                         error = im6f_get_source(imf, psin, &lims);
 2497                         if (error)
 2498                                 break;
 2499                         lims->im6sl_st[1] = imf->im6f_st[1];
 2500                 }
 2501                 free(kss, M_TEMP);
 2502         }
 2503 
 2504         if (error)
 2505                 goto out_im6f_rollback;
 2506 
 2507         INP_WLOCK_ASSERT(inp);
 2508         IN6_MULTI_LOCK();
 2509 
 2510         /*
 2511          * Begin state merge transaction at MLD layer.
 2512          */
 2513         CTR1(KTR_MLD, "%s: merge inm state", __func__);
 2514         error = in6m_merge(inm, imf);
 2515         if (error)
 2516                 CTR1(KTR_MLD, "%s: failed to merge inm state", __func__);
 2517         else {
 2518                 CTR1(KTR_MLD, "%s: doing mld downcall", __func__);
 2519                 error = mld_change_state(inm, 0);
 2520                 if (error)
 2521                         CTR1(KTR_MLD, "%s: failed mld downcall", __func__);
 2522         }
 2523 
 2524         IN6_MULTI_UNLOCK();
 2525 
 2526 out_im6f_rollback:
 2527         if (error)
 2528                 im6f_rollback(imf);
 2529         else
 2530                 im6f_commit(imf);
 2531 
 2532         im6f_reap(imf);
 2533 
 2534 out_in6p_locked:
 2535         INP_WUNLOCK(inp);
 2536         return (error);
 2537 }
 2538 
 2539 /*
 2540  * Set the IP multicast options in response to user setsockopt().
 2541  *
 2542  * Many of the socket options handled in this function duplicate the
 2543  * functionality of socket options in the regular unicast API. However,
 2544  * it is not possible to merge the duplicate code, because the idempotence
 2545  * of the IPv6 multicast part of the BSD Sockets API must be preserved;
 2546  * the effects of these options must be treated as separate and distinct.
 2547  *
 2548  * SMPng: XXX: Unlocked read of inp_socket believed OK.
 2549  */
 2550 int
 2551 ip6_setmoptions(struct inpcb *inp, struct sockopt *sopt)
 2552 {
 2553         struct ip6_moptions     *im6o;
 2554         int                      error;
 2555 
 2556         error = 0;
 2557 
 2558         /*
 2559          * If socket is neither of type SOCK_RAW or SOCK_DGRAM,
 2560          * or is a divert socket, reject it.
 2561          */
 2562         if (inp->inp_socket->so_proto->pr_protocol == IPPROTO_DIVERT ||
 2563             (inp->inp_socket->so_proto->pr_type != SOCK_RAW &&
 2564              inp->inp_socket->so_proto->pr_type != SOCK_DGRAM))
 2565                 return (EOPNOTSUPP);
 2566 
 2567         switch (sopt->sopt_name) {
 2568         case IPV6_MULTICAST_IF:
 2569                 error = in6p_set_multicast_if(inp, sopt);
 2570                 break;
 2571 
 2572         case IPV6_MULTICAST_HOPS: {
 2573                 int hlim;
 2574 
 2575                 if (sopt->sopt_valsize != sizeof(int)) {
 2576                         error = EINVAL;
 2577                         break;
 2578                 }
 2579                 error = sooptcopyin(sopt, &hlim, sizeof(hlim), sizeof(int));
 2580                 if (error)
 2581                         break;
 2582                 if (hlim < -1 || hlim > 255) {
 2583                         error = EINVAL;
 2584                         break;
 2585                 } else if (hlim == -1) {
 2586                         hlim = V_ip6_defmcasthlim;
 2587                 }
 2588                 im6o = in6p_findmoptions(inp);
 2589                 im6o->im6o_multicast_hlim = hlim;
 2590                 INP_WUNLOCK(inp);
 2591                 break;
 2592         }
 2593 
 2594         case IPV6_MULTICAST_LOOP: {
 2595                 u_int loop;
 2596 
 2597                 /*
 2598                  * Set the loopback flag for outgoing multicast packets.
 2599                  * Must be zero or one.
 2600                  */
 2601                 if (sopt->sopt_valsize != sizeof(u_int)) {
 2602                         error = EINVAL;
 2603                         break;
 2604                 }
 2605                 error = sooptcopyin(sopt, &loop, sizeof(u_int), sizeof(u_int));
 2606                 if (error)
 2607                         break;
 2608                 if (loop > 1) {
 2609                         error = EINVAL;
 2610                         break;
 2611                 }
 2612                 im6o = in6p_findmoptions(inp);
 2613                 im6o->im6o_multicast_loop = loop;
 2614                 INP_WUNLOCK(inp);
 2615                 break;
 2616         }
 2617 
 2618         case IPV6_JOIN_GROUP:
 2619         case MCAST_JOIN_GROUP:
 2620         case MCAST_JOIN_SOURCE_GROUP:
 2621                 error = in6p_join_group(inp, sopt);
 2622                 break;
 2623 
 2624         case IPV6_LEAVE_GROUP:
 2625         case MCAST_LEAVE_GROUP:
 2626         case MCAST_LEAVE_SOURCE_GROUP:
 2627                 error = in6p_leave_group(inp, sopt);
 2628                 break;
 2629 
 2630         case MCAST_BLOCK_SOURCE:
 2631         case MCAST_UNBLOCK_SOURCE:
 2632                 error = in6p_block_unblock_source(inp, sopt);
 2633                 break;
 2634 
 2635         case IPV6_MSFILTER:
 2636                 error = in6p_set_source_filters(inp, sopt);
 2637                 break;
 2638 
 2639         default:
 2640                 error = EOPNOTSUPP;
 2641                 break;
 2642         }
 2643 
 2644         INP_UNLOCK_ASSERT(inp);
 2645 
 2646         return (error);
 2647 }
 2648 
 2649 /*
 2650  * Expose MLD's multicast filter mode and source list(s) to userland,
 2651  * keyed by (ifindex, group).
 2652  * The filter mode is written out as a uint32_t, followed by
 2653  * 0..n of struct in6_addr.
 2654  * For use by ifmcstat(8).
 2655  * SMPng: NOTE: unlocked read of ifindex space.
 2656  */
 2657 static int
 2658 sysctl_ip6_mcast_filters(SYSCTL_HANDLER_ARGS)
 2659 {
 2660         struct in6_addr                  mcaddr;
 2661         struct in6_addr                  src;
 2662         struct ifnet                    *ifp;
 2663         struct ifmultiaddr              *ifma;
 2664         struct in6_multi                *inm;
 2665         struct ip6_msource              *ims;
 2666         int                             *name;
 2667         int                              retval;
 2668         u_int                            namelen;
 2669         uint32_t                         fmode, ifindex;
 2670 #ifdef KTR
 2671         char                             ip6tbuf[INET6_ADDRSTRLEN];
 2672 #endif
 2673 
 2674         name = (int *)arg1;
 2675         namelen = arg2;
 2676 
 2677         if (req->newptr != NULL)
 2678                 return (EPERM);
 2679 
 2680         /* int: ifindex + 4 * 32 bits of IPv6 address */
 2681         if (namelen != 5)
 2682                 return (EINVAL);
 2683 
 2684         ifindex = name[0];
 2685         if (ifindex <= 0 || ifindex > V_if_index) {
 2686                 CTR2(KTR_MLD, "%s: ifindex %u out of range",
 2687                     __func__, ifindex);
 2688                 return (ENOENT);
 2689         }
 2690 
 2691         memcpy(&mcaddr, &name[1], sizeof(struct in6_addr));
 2692         if (!IN6_IS_ADDR_MULTICAST(&mcaddr)) {
 2693                 CTR2(KTR_MLD, "%s: group %s is not multicast",
 2694                     __func__, ip6_sprintf(ip6tbuf, &mcaddr));
 2695                 return (EINVAL);
 2696         }
 2697 
 2698         ifp = ifnet_byindex(ifindex);
 2699         if (ifp == NULL) {
 2700                 CTR2(KTR_MLD, "%s: no ifp for ifindex %u",
 2701                     __func__, ifindex);
 2702                 return (ENOENT);
 2703         }
 2704         /*
 2705          * Internal MLD lookups require that scope/zone ID is set.
 2706          */
 2707         (void)in6_setscope(&mcaddr, ifp, NULL);
 2708 
 2709         retval = sysctl_wire_old_buffer(req,
 2710             sizeof(uint32_t) + (in6_mcast_maxgrpsrc * sizeof(struct in6_addr)));
 2711         if (retval)
 2712                 return (retval);
 2713 
 2714         IN6_MULTI_LOCK();
 2715 
 2716         IF_ADDR_RLOCK(ifp);
 2717         TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
 2718                 if (ifma->ifma_addr->sa_family != AF_INET6 ||
 2719                     ifma->ifma_protospec == NULL)
 2720                         continue;
 2721                 inm = (struct in6_multi *)ifma->ifma_protospec;
 2722                 if (!IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, &mcaddr))
 2723                         continue;
 2724                 fmode = inm->in6m_st[1].iss_fmode;
 2725                 retval = SYSCTL_OUT(req, &fmode, sizeof(uint32_t));
 2726                 if (retval != 0)
 2727                         break;
 2728                 RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
 2729                         CTR2(KTR_MLD, "%s: visit node %p", __func__, ims);
 2730                         /*
 2731                          * Only copy-out sources which are in-mode.
 2732                          */
 2733                         if (fmode != im6s_get_mode(inm, ims, 1)) {
 2734                                 CTR1(KTR_MLD, "%s: skip non-in-mode",
 2735                                     __func__);
 2736                                 continue;
 2737                         }
 2738                         src = ims->im6s_addr;
 2739                         retval = SYSCTL_OUT(req, &src,
 2740                             sizeof(struct in6_addr));
 2741                         if (retval != 0)
 2742                                 break;
 2743                 }
 2744         }
 2745         IF_ADDR_RUNLOCK(ifp);
 2746 
 2747         IN6_MULTI_UNLOCK();
 2748 
 2749         return (retval);
 2750 }
 2751 
 2752 #ifdef KTR
 2753 
 2754 static const char *in6m_modestrs[] = { "un", "in", "ex" };
 2755 
 2756 static const char *
 2757 in6m_mode_str(const int mode)
 2758 {
 2759 
 2760         if (mode >= MCAST_UNDEFINED && mode <= MCAST_EXCLUDE)
 2761                 return (in6m_modestrs[mode]);
 2762         return ("??");
 2763 }
 2764 
 2765 static const char *in6m_statestrs[] = {
 2766         "not-member",
 2767         "silent",
 2768         "idle",
 2769         "lazy",
 2770         "sleeping",
 2771         "awakening",
 2772         "query-pending",
 2773         "sg-query-pending",
 2774         "leaving"
 2775 };
 2776 
 2777 static const char *
 2778 in6m_state_str(const int state)
 2779 {
 2780 
 2781         if (state >= MLD_NOT_MEMBER && state <= MLD_LEAVING_MEMBER)
 2782                 return (in6m_statestrs[state]);
 2783         return ("??");
 2784 }
 2785 
 2786 /*
 2787  * Dump an in6_multi structure to the console.
 2788  */
 2789 void
 2790 in6m_print(const struct in6_multi *inm)
 2791 {
 2792         int t;
 2793         char ip6tbuf[INET6_ADDRSTRLEN];
 2794 
 2795         if ((ktr_mask & KTR_MLD) == 0)
 2796                 return;
 2797 
 2798         printf("%s: --- begin in6m %p ---\n", __func__, inm);
 2799         printf("addr %s ifp %p(%s) ifma %p\n",
 2800             ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2801             inm->in6m_ifp,
 2802             if_name(inm->in6m_ifp),
 2803             inm->in6m_ifma);
 2804         printf("timer %u state %s refcount %u scq.len %u\n",
 2805             inm->in6m_timer,
 2806             in6m_state_str(inm->in6m_state),
 2807             inm->in6m_refcount,
 2808             mbufq_len(&inm->in6m_scq));
 2809         printf("mli %p nsrc %lu sctimer %u scrv %u\n",
 2810             inm->in6m_mli,
 2811             inm->in6m_nsrc,
 2812             inm->in6m_sctimer,
 2813             inm->in6m_scrv);
 2814         for (t = 0; t < 2; t++) {
 2815                 printf("t%d: fmode %s asm %u ex %u in %u rec %u\n", t,
 2816                     in6m_mode_str(inm->in6m_st[t].iss_fmode),
 2817                     inm->in6m_st[t].iss_asm,
 2818                     inm->in6m_st[t].iss_ex,
 2819                     inm->in6m_st[t].iss_in,
 2820                     inm->in6m_st[t].iss_rec);
 2821         }
 2822         printf("%s: --- end in6m %p ---\n", __func__, inm);
 2823 }
 2824 
 2825 #else /* !KTR */
 2826 
 2827 void
 2828 in6m_print(const struct in6_multi *inm)
 2829 {
 2830 
 2831 }
 2832 
 2833 #endif /* KTR */

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