The Design and Implementation of the FreeBSD Operating System, Second Edition
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sys/netinet6/mld6.c

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    1 /*-
    2  * Copyright (c) 2009 Bruce Simpson.
    3  *
    4  * Redistribution and use in source and binary forms, with or without
    5  * modification, are permitted provided that the following conditions
    6  * are met:
    7  * 1. Redistributions of source code must retain the above copyright
    8  *    notice, this list of conditions and the following disclaimer.
    9  * 2. Redistributions in binary form must reproduce the above copyright
   10  *    notice, this list of conditions and the following disclaimer in the
   11  *    documentation and/or other materials provided with the distribution.
   12  * 3. The name of the author may not be used to endorse or promote
   13  *    products derived from this software without specific prior written
   14  *    permission.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  *
   28  *      $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $
   29  */
   30 
   31 /*-
   32  * Copyright (c) 1988 Stephen Deering.
   33  * Copyright (c) 1992, 1993
   34  *      The Regents of the University of California.  All rights reserved.
   35  *
   36  * This code is derived from software contributed to Berkeley by
   37  * Stephen Deering of Stanford University.
   38  *
   39  * Redistribution and use in source and binary forms, with or without
   40  * modification, are permitted provided that the following conditions
   41  * are met:
   42  * 1. Redistributions of source code must retain the above copyright
   43  *    notice, this list of conditions and the following disclaimer.
   44  * 2. Redistributions in binary form must reproduce the above copyright
   45  *    notice, this list of conditions and the following disclaimer in the
   46  *    documentation and/or other materials provided with the distribution.
   47  * 4. Neither the name of the University nor the names of its contributors
   48  *    may be used to endorse or promote products derived from this software
   49  *    without specific prior written permission.
   50  *
   51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   61  * SUCH DAMAGE.
   62  *
   63  *      @(#)igmp.c      8.1 (Berkeley) 7/19/93
   64  */
   65 
   66 #include <sys/cdefs.h>
   67 __FBSDID("$FreeBSD: releng/11.1/sys/netinet6/mld6.c 302054 2016-06-21 13:48:49Z bz $");
   68 
   69 #include "opt_inet.h"
   70 #include "opt_inet6.h"
   71 
   72 #include <sys/param.h>
   73 #include <sys/systm.h>
   74 #include <sys/mbuf.h>
   75 #include <sys/socket.h>
   76 #include <sys/protosw.h>
   77 #include <sys/sysctl.h>
   78 #include <sys/kernel.h>
   79 #include <sys/callout.h>
   80 #include <sys/malloc.h>
   81 #include <sys/module.h>
   82 #include <sys/ktr.h>
   83 
   84 #include <net/if.h>
   85 #include <net/if_var.h>
   86 #include <net/route.h>
   87 #include <net/vnet.h>
   88 
   89 #include <netinet/in.h>
   90 #include <netinet/in_var.h>
   91 #include <netinet6/in6_var.h>
   92 #include <netinet/ip6.h>
   93 #include <netinet6/ip6_var.h>
   94 #include <netinet6/scope6_var.h>
   95 #include <netinet/icmp6.h>
   96 #include <netinet6/mld6.h>
   97 #include <netinet6/mld6_var.h>
   98 
   99 #include <security/mac/mac_framework.h>
  100 
  101 #ifndef KTR_MLD
  102 #define KTR_MLD KTR_INET6
  103 #endif
  104 
  105 static struct mld_ifsoftc *
  106                 mli_alloc_locked(struct ifnet *);
  107 static void     mli_delete_locked(const struct ifnet *);
  108 static void     mld_dispatch_packet(struct mbuf *);
  109 static void     mld_dispatch_queue(struct mbufq *, int);
  110 static void     mld_final_leave(struct in6_multi *, struct mld_ifsoftc *);
  111 static void     mld_fasttimo_vnet(void);
  112 static int      mld_handle_state_change(struct in6_multi *,
  113                     struct mld_ifsoftc *);
  114 static int      mld_initial_join(struct in6_multi *, struct mld_ifsoftc *,
  115                     const int);
  116 #ifdef KTR
  117 static char *   mld_rec_type_to_str(const int);
  118 #endif
  119 static void     mld_set_version(struct mld_ifsoftc *, const int);
  120 static void     mld_slowtimo_vnet(void);
  121 static int      mld_v1_input_query(struct ifnet *, const struct ip6_hdr *,
  122                     /*const*/ struct mld_hdr *);
  123 static int      mld_v1_input_report(struct ifnet *, const struct ip6_hdr *,
  124                     /*const*/ struct mld_hdr *);
  125 static void     mld_v1_process_group_timer(struct mld_ifsoftc *,
  126                     struct in6_multi *);
  127 static void     mld_v1_process_querier_timers(struct mld_ifsoftc *);
  128 static int      mld_v1_transmit_report(struct in6_multi *, const int);
  129 static void     mld_v1_update_group(struct in6_multi *, const int);
  130 static void     mld_v2_cancel_link_timers(struct mld_ifsoftc *);
  131 static void     mld_v2_dispatch_general_query(struct mld_ifsoftc *);
  132 static struct mbuf *
  133                 mld_v2_encap_report(struct ifnet *, struct mbuf *);
  134 static int      mld_v2_enqueue_filter_change(struct mbufq *,
  135                     struct in6_multi *);
  136 static int      mld_v2_enqueue_group_record(struct mbufq *,
  137                     struct in6_multi *, const int, const int, const int,
  138                     const int);
  139 static int      mld_v2_input_query(struct ifnet *, const struct ip6_hdr *,
  140                     struct mbuf *, const int, const int);
  141 static int      mld_v2_merge_state_changes(struct in6_multi *,
  142                     struct mbufq *);
  143 static void     mld_v2_process_group_timers(struct mld_ifsoftc *,
  144                     struct mbufq *, struct mbufq *,
  145                     struct in6_multi *, const int);
  146 static int      mld_v2_process_group_query(struct in6_multi *,
  147                     struct mld_ifsoftc *mli, int, struct mbuf *, const int);
  148 static int      sysctl_mld_gsr(SYSCTL_HANDLER_ARGS);
  149 static int      sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS);
  150 
  151 /*
  152  * Normative references: RFC 2710, RFC 3590, RFC 3810.
  153  *
  154  * Locking:
  155  *  * The MLD subsystem lock ends up being system-wide for the moment,
  156  *    but could be per-VIMAGE later on.
  157  *  * The permitted lock order is: IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
  158  *    Any may be taken independently; if any are held at the same
  159  *    time, the above lock order must be followed.
  160  *  * IN6_MULTI_LOCK covers in_multi.
  161  *  * MLD_LOCK covers per-link state and any global variables in this file.
  162  *  * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
  163  *    per-link state iterators.
  164  *
  165  *  XXX LOR PREVENTION
  166  *  A special case for IPv6 is the in6_setscope() routine. ip6_output()
  167  *  will not accept an ifp; it wants an embedded scope ID, unlike
  168  *  ip_output(), which happily takes the ifp given to it. The embedded
  169  *  scope ID is only used by MLD to select the outgoing interface.
  170  *
  171  *  During interface attach and detach, MLD will take MLD_LOCK *after*
  172  *  the IF_AFDATA_LOCK.
  173  *  As in6_setscope() takes IF_AFDATA_LOCK then SCOPE_LOCK, we can't call
  174  *  it with MLD_LOCK held without triggering an LOR. A netisr with indirect
  175  *  dispatch could work around this, but we'd rather not do that, as it
  176  *  can introduce other races.
  177  *
  178  *  As such, we exploit the fact that the scope ID is just the interface
  179  *  index, and embed it in the IPv6 destination address accordingly.
  180  *  This is potentially NOT VALID for MLDv1 reports, as they
  181  *  are always sent to the multicast group itself; as MLDv2
  182  *  reports are always sent to ff02::16, this is not an issue
  183  *  when MLDv2 is in use.
  184  *
  185  *  This does not however eliminate the LOR when ip6_output() itself
  186  *  calls in6_setscope() internally whilst MLD_LOCK is held. This will
  187  *  trigger a LOR warning in WITNESS when the ifnet is detached.
  188  *
  189  *  The right answer is probably to make IF_AFDATA_LOCK an rwlock, given
  190  *  how it's used across the network stack. Here we're simply exploiting
  191  *  the fact that MLD runs at a similar layer in the stack to scope6.c.
  192  *
  193  * VIMAGE:
  194  *  * Each in6_multi corresponds to an ifp, and each ifp corresponds
  195  *    to a vnet in ifp->if_vnet.
  196  */
  197 static struct mtx                mld_mtx;
  198 static MALLOC_DEFINE(M_MLD, "mld", "mld state");
  199 
  200 #define MLD_EMBEDSCOPE(pin6, zoneid)                                    \
  201         if (IN6_IS_SCOPE_LINKLOCAL(pin6) ||                             \
  202             IN6_IS_ADDR_MC_INTFACELOCAL(pin6))                          \
  203                 (pin6)->s6_addr16[1] = htons((zoneid) & 0xFFFF)         \
  204 
  205 /*
  206  * VIMAGE-wide globals.
  207  */
  208 static VNET_DEFINE(struct timeval, mld_gsrdelay) = {10, 0};
  209 static VNET_DEFINE(LIST_HEAD(, mld_ifsoftc), mli_head);
  210 static VNET_DEFINE(int, interface_timers_running6);
  211 static VNET_DEFINE(int, state_change_timers_running6);
  212 static VNET_DEFINE(int, current_state_timers_running6);
  213 
  214 #define V_mld_gsrdelay                  VNET(mld_gsrdelay)
  215 #define V_mli_head                      VNET(mli_head)
  216 #define V_interface_timers_running6     VNET(interface_timers_running6)
  217 #define V_state_change_timers_running6  VNET(state_change_timers_running6)
  218 #define V_current_state_timers_running6 VNET(current_state_timers_running6)
  219 
  220 SYSCTL_DECL(_net_inet6);        /* Note: Not in any common header. */
  221 
  222 SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW, 0,
  223     "IPv6 Multicast Listener Discovery");
  224 
  225 /*
  226  * Virtualized sysctls.
  227  */
  228 SYSCTL_PROC(_net_inet6_mld, OID_AUTO, gsrdelay,
  229     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
  230     &VNET_NAME(mld_gsrdelay.tv_sec), 0, sysctl_mld_gsr, "I",
  231     "Rate limit for MLDv2 Group-and-Source queries in seconds");
  232 
  233 /*
  234  * Non-virtualized sysctls.
  235  */
  236 static SYSCTL_NODE(_net_inet6_mld, OID_AUTO, ifinfo,
  237     CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_mld_ifinfo,
  238     "Per-interface MLDv2 state");
  239 
  240 static int      mld_v1enable = 1;
  241 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v1enable, CTLFLAG_RWTUN,
  242     &mld_v1enable, 0, "Enable fallback to MLDv1");
  243 
  244 static int      mld_use_allow = 1;
  245 SYSCTL_INT(_net_inet6_mld, OID_AUTO, use_allow, CTLFLAG_RWTUN,
  246     &mld_use_allow, 0, "Use ALLOW/BLOCK for RFC 4604 SSM joins/leaves");
  247 
  248 /*
  249  * Packed Router Alert option structure declaration.
  250  */
  251 struct mld_raopt {
  252         struct ip6_hbh          hbh;
  253         struct ip6_opt          pad;
  254         struct ip6_opt_router   ra;
  255 } __packed;
  256 
  257 /*
  258  * Router Alert hop-by-hop option header.
  259  */
  260 static struct mld_raopt mld_ra = {
  261         .hbh = { 0, 0 },
  262         .pad = { .ip6o_type = IP6OPT_PADN, 0 },
  263         .ra = {
  264             .ip6or_type = IP6OPT_ROUTER_ALERT,
  265             .ip6or_len = IP6OPT_RTALERT_LEN - 2,
  266             .ip6or_value[0] = ((IP6OPT_RTALERT_MLD >> 8) & 0xFF),
  267             .ip6or_value[1] = (IP6OPT_RTALERT_MLD & 0xFF)
  268         }
  269 };
  270 static struct ip6_pktopts mld_po;
  271 
  272 static __inline void
  273 mld_save_context(struct mbuf *m, struct ifnet *ifp)
  274 {
  275 
  276 #ifdef VIMAGE
  277         m->m_pkthdr.PH_loc.ptr = ifp->if_vnet;
  278 #endif /* VIMAGE */
  279         m->m_pkthdr.flowid = ifp->if_index;
  280 }
  281 
  282 static __inline void
  283 mld_scrub_context(struct mbuf *m)
  284 {
  285 
  286         m->m_pkthdr.PH_loc.ptr = NULL;
  287         m->m_pkthdr.flowid = 0;
  288 }
  289 
  290 /*
  291  * Restore context from a queued output chain.
  292  * Return saved ifindex.
  293  *
  294  * VIMAGE: The assertion is there to make sure that we
  295  * actually called CURVNET_SET() with what's in the mbuf chain.
  296  */
  297 static __inline uint32_t
  298 mld_restore_context(struct mbuf *m)
  299 {
  300 
  301 #if defined(VIMAGE) && defined(INVARIANTS)
  302         KASSERT(curvnet == m->m_pkthdr.PH_loc.ptr,
  303             ("%s: called when curvnet was not restored: cuvnet %p m ptr %p",
  304             __func__, curvnet, m->m_pkthdr.PH_loc.ptr));
  305 #endif
  306         return (m->m_pkthdr.flowid);
  307 }
  308 
  309 /*
  310  * Retrieve or set threshold between group-source queries in seconds.
  311  *
  312  * VIMAGE: Assume curvnet set by caller.
  313  * SMPng: NOTE: Serialized by MLD lock.
  314  */
  315 static int
  316 sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
  317 {
  318         int error;
  319         int i;
  320 
  321         error = sysctl_wire_old_buffer(req, sizeof(int));
  322         if (error)
  323                 return (error);
  324 
  325         MLD_LOCK();
  326 
  327         i = V_mld_gsrdelay.tv_sec;
  328 
  329         error = sysctl_handle_int(oidp, &i, 0, req);
  330         if (error || !req->newptr)
  331                 goto out_locked;
  332 
  333         if (i < -1 || i >= 60) {
  334                 error = EINVAL;
  335                 goto out_locked;
  336         }
  337 
  338         CTR2(KTR_MLD, "change mld_gsrdelay from %d to %d",
  339              V_mld_gsrdelay.tv_sec, i);
  340         V_mld_gsrdelay.tv_sec = i;
  341 
  342 out_locked:
  343         MLD_UNLOCK();
  344         return (error);
  345 }
  346 
  347 /*
  348  * Expose struct mld_ifsoftc to userland, keyed by ifindex.
  349  * For use by ifmcstat(8).
  350  *
  351  * SMPng: NOTE: Does an unlocked ifindex space read.
  352  * VIMAGE: Assume curvnet set by caller. The node handler itself
  353  * is not directly virtualized.
  354  */
  355 static int
  356 sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
  357 {
  358         int                     *name;
  359         int                      error;
  360         u_int                    namelen;
  361         struct ifnet            *ifp;
  362         struct mld_ifsoftc      *mli;
  363 
  364         name = (int *)arg1;
  365         namelen = arg2;
  366 
  367         if (req->newptr != NULL)
  368                 return (EPERM);
  369 
  370         if (namelen != 1)
  371                 return (EINVAL);
  372 
  373         error = sysctl_wire_old_buffer(req, sizeof(struct mld_ifinfo));
  374         if (error)
  375                 return (error);
  376 
  377         IN6_MULTI_LOCK();
  378         MLD_LOCK();
  379 
  380         if (name[0] <= 0 || name[0] > V_if_index) {
  381                 error = ENOENT;
  382                 goto out_locked;
  383         }
  384 
  385         error = ENOENT;
  386 
  387         ifp = ifnet_byindex(name[0]);
  388         if (ifp == NULL)
  389                 goto out_locked;
  390 
  391         LIST_FOREACH(mli, &V_mli_head, mli_link) {
  392                 if (ifp == mli->mli_ifp) {
  393                         struct mld_ifinfo info;
  394 
  395                         info.mli_version = mli->mli_version;
  396                         info.mli_v1_timer = mli->mli_v1_timer;
  397                         info.mli_v2_timer = mli->mli_v2_timer;
  398                         info.mli_flags = mli->mli_flags;
  399                         info.mli_rv = mli->mli_rv;
  400                         info.mli_qi = mli->mli_qi;
  401                         info.mli_qri = mli->mli_qri;
  402                         info.mli_uri = mli->mli_uri;
  403                         error = SYSCTL_OUT(req, &info, sizeof(info));
  404                         break;
  405                 }
  406         }
  407 
  408 out_locked:
  409         MLD_UNLOCK();
  410         IN6_MULTI_UNLOCK();
  411         return (error);
  412 }
  413 
  414 /*
  415  * Dispatch an entire queue of pending packet chains.
  416  * VIMAGE: Assumes the vnet pointer has been set.
  417  */
  418 static void
  419 mld_dispatch_queue(struct mbufq *mq, int limit)
  420 {
  421         struct mbuf *m;
  422 
  423         while ((m = mbufq_dequeue(mq)) != NULL) {
  424                 CTR3(KTR_MLD, "%s: dispatch %p from %p", __func__, mq, m);
  425                 mld_dispatch_packet(m);
  426                 if (--limit == 0)
  427                         break;
  428         }
  429 }
  430 
  431 /*
  432  * Filter outgoing MLD report state by group.
  433  *
  434  * Reports are ALWAYS suppressed for ALL-HOSTS (ff02::1)
  435  * and node-local addresses. However, kernel and socket consumers
  436  * always embed the KAME scope ID in the address provided, so strip it
  437  * when performing comparison.
  438  * Note: This is not the same as the *multicast* scope.
  439  *
  440  * Return zero if the given group is one for which MLD reports
  441  * should be suppressed, or non-zero if reports should be issued.
  442  */
  443 static __inline int
  444 mld_is_addr_reported(const struct in6_addr *addr)
  445 {
  446 
  447         KASSERT(IN6_IS_ADDR_MULTICAST(addr), ("%s: not multicast", __func__));
  448 
  449         if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_NODELOCAL)
  450                 return (0);
  451 
  452         if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_LINKLOCAL) {
  453                 struct in6_addr tmp = *addr;
  454                 in6_clearscope(&tmp);
  455                 if (IN6_ARE_ADDR_EQUAL(&tmp, &in6addr_linklocal_allnodes))
  456                         return (0);
  457         }
  458 
  459         return (1);
  460 }
  461 
  462 /*
  463  * Attach MLD when PF_INET6 is attached to an interface.
  464  *
  465  * SMPng: Normally called with IF_AFDATA_LOCK held.
  466  */
  467 struct mld_ifsoftc *
  468 mld_domifattach(struct ifnet *ifp)
  469 {
  470         struct mld_ifsoftc *mli;
  471 
  472         CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
  473             __func__, ifp, if_name(ifp));
  474 
  475         MLD_LOCK();
  476 
  477         mli = mli_alloc_locked(ifp);
  478         if (!(ifp->if_flags & IFF_MULTICAST))
  479                 mli->mli_flags |= MLIF_SILENT;
  480         if (mld_use_allow)
  481                 mli->mli_flags |= MLIF_USEALLOW;
  482 
  483         MLD_UNLOCK();
  484 
  485         return (mli);
  486 }
  487 
  488 /*
  489  * VIMAGE: assume curvnet set by caller.
  490  */
  491 static struct mld_ifsoftc *
  492 mli_alloc_locked(/*const*/ struct ifnet *ifp)
  493 {
  494         struct mld_ifsoftc *mli;
  495 
  496         MLD_LOCK_ASSERT();
  497 
  498         mli = malloc(sizeof(struct mld_ifsoftc), M_MLD, M_NOWAIT|M_ZERO);
  499         if (mli == NULL)
  500                 goto out;
  501 
  502         mli->mli_ifp = ifp;
  503         mli->mli_version = MLD_VERSION_2;
  504         mli->mli_flags = 0;
  505         mli->mli_rv = MLD_RV_INIT;
  506         mli->mli_qi = MLD_QI_INIT;
  507         mli->mli_qri = MLD_QRI_INIT;
  508         mli->mli_uri = MLD_URI_INIT;
  509         SLIST_INIT(&mli->mli_relinmhead);
  510         mbufq_init(&mli->mli_gq, MLD_MAX_RESPONSE_PACKETS);
  511 
  512         LIST_INSERT_HEAD(&V_mli_head, mli, mli_link);
  513 
  514         CTR2(KTR_MLD, "allocate mld_ifsoftc for ifp %p(%s)",
  515              ifp, if_name(ifp));
  516 
  517 out:
  518         return (mli);
  519 }
  520 
  521 /*
  522  * Hook for ifdetach.
  523  *
  524  * NOTE: Some finalization tasks need to run before the protocol domain
  525  * is detached, but also before the link layer does its cleanup.
  526  * Run before link-layer cleanup; cleanup groups, but do not free MLD state.
  527  *
  528  * SMPng: Caller must hold IN6_MULTI_LOCK().
  529  * Must take IF_ADDR_LOCK() to cover if_multiaddrs iterator.
  530  * XXX This routine is also bitten by unlocked ifma_protospec access.
  531  */
  532 void
  533 mld_ifdetach(struct ifnet *ifp)
  534 {
  535         struct mld_ifsoftc      *mli;
  536         struct ifmultiaddr      *ifma;
  537         struct in6_multi        *inm, *tinm;
  538 
  539         CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp,
  540             if_name(ifp));
  541 
  542         IN6_MULTI_LOCK_ASSERT();
  543         MLD_LOCK();
  544 
  545         mli = MLD_IFINFO(ifp);
  546         if (mli->mli_version == MLD_VERSION_2) {
  547                 IF_ADDR_RLOCK(ifp);
  548                 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
  549                         if (ifma->ifma_addr->sa_family != AF_INET6 ||
  550                             ifma->ifma_protospec == NULL)
  551                                 continue;
  552                         inm = (struct in6_multi *)ifma->ifma_protospec;
  553                         if (inm->in6m_state == MLD_LEAVING_MEMBER) {
  554                                 SLIST_INSERT_HEAD(&mli->mli_relinmhead,
  555                                     inm, in6m_nrele);
  556                         }
  557                         in6m_clear_recorded(inm);
  558                 }
  559                 IF_ADDR_RUNLOCK(ifp);
  560                 SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead, in6m_nrele,
  561                     tinm) {
  562                         SLIST_REMOVE_HEAD(&mli->mli_relinmhead, in6m_nrele);
  563                         in6m_release_locked(inm);
  564                 }
  565         }
  566 
  567         MLD_UNLOCK();
  568 }
  569 
  570 /*
  571  * Hook for domifdetach.
  572  * Runs after link-layer cleanup; free MLD state.
  573  *
  574  * SMPng: Normally called with IF_AFDATA_LOCK held.
  575  */
  576 void
  577 mld_domifdetach(struct ifnet *ifp)
  578 {
  579 
  580         CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
  581             __func__, ifp, if_name(ifp));
  582 
  583         MLD_LOCK();
  584         mli_delete_locked(ifp);
  585         MLD_UNLOCK();
  586 }
  587 
  588 static void
  589 mli_delete_locked(const struct ifnet *ifp)
  590 {
  591         struct mld_ifsoftc *mli, *tmli;
  592 
  593         CTR3(KTR_MLD, "%s: freeing mld_ifsoftc for ifp %p(%s)",
  594             __func__, ifp, if_name(ifp));
  595 
  596         MLD_LOCK_ASSERT();
  597 
  598         LIST_FOREACH_SAFE(mli, &V_mli_head, mli_link, tmli) {
  599                 if (mli->mli_ifp == ifp) {
  600                         /*
  601                          * Free deferred General Query responses.
  602                          */
  603                         mbufq_drain(&mli->mli_gq);
  604 
  605                         LIST_REMOVE(mli, mli_link);
  606 
  607                         KASSERT(SLIST_EMPTY(&mli->mli_relinmhead),
  608                             ("%s: there are dangling in_multi references",
  609                             __func__));
  610 
  611                         free(mli, M_MLD);
  612                         return;
  613                 }
  614         }
  615 }
  616 
  617 /*
  618  * Process a received MLDv1 general or address-specific query.
  619  * Assumes that the query header has been pulled up to sizeof(mld_hdr).
  620  *
  621  * NOTE: Can't be fully const correct as we temporarily embed scope ID in
  622  * mld_addr. This is OK as we own the mbuf chain.
  623  */
  624 static int
  625 mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
  626     /*const*/ struct mld_hdr *mld)
  627 {
  628         struct ifmultiaddr      *ifma;
  629         struct mld_ifsoftc      *mli;
  630         struct in6_multi        *inm;
  631         int                      is_general_query;
  632         uint16_t                 timer;
  633 #ifdef KTR
  634         char                     ip6tbuf[INET6_ADDRSTRLEN];
  635 #endif
  636 
  637         is_general_query = 0;
  638 
  639         if (!mld_v1enable) {
  640                 CTR3(KTR_MLD, "ignore v1 query %s on ifp %p(%s)",
  641                     ip6_sprintf(ip6tbuf, &mld->mld_addr),
  642                     ifp, if_name(ifp));
  643                 return (0);
  644         }
  645 
  646         /*
  647          * RFC3810 Section 6.2: MLD queries must originate from
  648          * a router's link-local address.
  649          */
  650         if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
  651                 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
  652                     ip6_sprintf(ip6tbuf, &ip6->ip6_src),
  653                     ifp, if_name(ifp));
  654                 return (0);
  655         }
  656 
  657         /*
  658          * Do address field validation upfront before we accept
  659          * the query.
  660          */
  661         if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
  662                 /*
  663                  * MLDv1 General Query.
  664                  * If this was not sent to the all-nodes group, ignore it.
  665                  */
  666                 struct in6_addr          dst;
  667 
  668                 dst = ip6->ip6_dst;
  669                 in6_clearscope(&dst);
  670                 if (!IN6_ARE_ADDR_EQUAL(&dst, &in6addr_linklocal_allnodes))
  671                         return (EINVAL);
  672                 is_general_query = 1;
  673         } else {
  674                 /*
  675                  * Embed scope ID of receiving interface in MLD query for
  676                  * lookup whilst we don't hold other locks.
  677                  */
  678                 in6_setscope(&mld->mld_addr, ifp, NULL);
  679         }
  680 
  681         IN6_MULTI_LOCK();
  682         MLD_LOCK();
  683 
  684         /*
  685          * Switch to MLDv1 host compatibility mode.
  686          */
  687         mli = MLD_IFINFO(ifp);
  688         KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
  689         mld_set_version(mli, MLD_VERSION_1);
  690 
  691         timer = (ntohs(mld->mld_maxdelay) * PR_FASTHZ) / MLD_TIMER_SCALE;
  692         if (timer == 0)
  693                 timer = 1;
  694 
  695         IF_ADDR_RLOCK(ifp);
  696         if (is_general_query) {
  697                 /*
  698                  * For each reporting group joined on this
  699                  * interface, kick the report timer.
  700                  */
  701                 CTR2(KTR_MLD, "process v1 general query on ifp %p(%s)",
  702                     ifp, if_name(ifp));
  703                 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
  704                         if (ifma->ifma_addr->sa_family != AF_INET6 ||
  705                             ifma->ifma_protospec == NULL)
  706                                 continue;
  707                         inm = (struct in6_multi *)ifma->ifma_protospec;
  708                         mld_v1_update_group(inm, timer);
  709                 }
  710         } else {
  711                 /*
  712                  * MLDv1 Group-Specific Query.
  713                  * If this is a group-specific MLDv1 query, we need only
  714                  * look up the single group to process it.
  715                  */
  716                 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
  717                 if (inm != NULL) {
  718                         CTR3(KTR_MLD, "process v1 query %s on ifp %p(%s)",
  719                             ip6_sprintf(ip6tbuf, &mld->mld_addr),
  720                             ifp, if_name(ifp));
  721                         mld_v1_update_group(inm, timer);
  722                 }
  723                 /* XXX Clear embedded scope ID as userland won't expect it. */
  724                 in6_clearscope(&mld->mld_addr);
  725         }
  726 
  727         IF_ADDR_RUNLOCK(ifp);
  728         MLD_UNLOCK();
  729         IN6_MULTI_UNLOCK();
  730 
  731         return (0);
  732 }
  733 
  734 /*
  735  * Update the report timer on a group in response to an MLDv1 query.
  736  *
  737  * If we are becoming the reporting member for this group, start the timer.
  738  * If we already are the reporting member for this group, and timer is
  739  * below the threshold, reset it.
  740  *
  741  * We may be updating the group for the first time since we switched
  742  * to MLDv2. If we are, then we must clear any recorded source lists,
  743  * and transition to REPORTING state; the group timer is overloaded
  744  * for group and group-source query responses. 
  745  *
  746  * Unlike MLDv2, the delay per group should be jittered
  747  * to avoid bursts of MLDv1 reports.
  748  */
  749 static void
  750 mld_v1_update_group(struct in6_multi *inm, const int timer)
  751 {
  752 #ifdef KTR
  753         char                     ip6tbuf[INET6_ADDRSTRLEN];
  754 #endif
  755 
  756         CTR4(KTR_MLD, "%s: %s/%s timer=%d", __func__,
  757             ip6_sprintf(ip6tbuf, &inm->in6m_addr),
  758             if_name(inm->in6m_ifp), timer);
  759 
  760         IN6_MULTI_LOCK_ASSERT();
  761 
  762         switch (inm->in6m_state) {
  763         case MLD_NOT_MEMBER:
  764         case MLD_SILENT_MEMBER:
  765                 break;
  766         case MLD_REPORTING_MEMBER:
  767                 if (inm->in6m_timer != 0 &&
  768                     inm->in6m_timer <= timer) {
  769                         CTR1(KTR_MLD, "%s: REPORTING and timer running, "
  770                             "skipping.", __func__);
  771                         break;
  772                 }
  773                 /* FALLTHROUGH */
  774         case MLD_SG_QUERY_PENDING_MEMBER:
  775         case MLD_G_QUERY_PENDING_MEMBER:
  776         case MLD_IDLE_MEMBER:
  777         case MLD_LAZY_MEMBER:
  778         case MLD_AWAKENING_MEMBER:
  779                 CTR1(KTR_MLD, "%s: ->REPORTING", __func__);
  780                 inm->in6m_state = MLD_REPORTING_MEMBER;
  781                 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
  782                 V_current_state_timers_running6 = 1;
  783                 break;
  784         case MLD_SLEEPING_MEMBER:
  785                 CTR1(KTR_MLD, "%s: ->AWAKENING", __func__);
  786                 inm->in6m_state = MLD_AWAKENING_MEMBER;
  787                 break;
  788         case MLD_LEAVING_MEMBER:
  789                 break;
  790         }
  791 }
  792 
  793 /*
  794  * Process a received MLDv2 general, group-specific or
  795  * group-and-source-specific query.
  796  *
  797  * Assumes that the query header has been pulled up to sizeof(mldv2_query).
  798  *
  799  * Return 0 if successful, otherwise an appropriate error code is returned.
  800  */
  801 static int
  802 mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
  803     struct mbuf *m, const int off, const int icmp6len)
  804 {
  805         struct mld_ifsoftc      *mli;
  806         struct mldv2_query      *mld;
  807         struct in6_multi        *inm;
  808         uint32_t                 maxdelay, nsrc, qqi;
  809         int                      is_general_query;
  810         uint16_t                 timer;
  811         uint8_t                  qrv;
  812 #ifdef KTR
  813         char                     ip6tbuf[INET6_ADDRSTRLEN];
  814 #endif
  815 
  816         is_general_query = 0;
  817 
  818         /*
  819          * RFC3810 Section 6.2: MLD queries must originate from
  820          * a router's link-local address.
  821          */
  822         if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
  823                 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
  824                     ip6_sprintf(ip6tbuf, &ip6->ip6_src),
  825                     ifp, if_name(ifp));
  826                 return (0);
  827         }
  828 
  829         CTR2(KTR_MLD, "input v2 query on ifp %p(%s)", ifp, if_name(ifp));
  830 
  831         mld = (struct mldv2_query *)(mtod(m, uint8_t *) + off);
  832 
  833         maxdelay = ntohs(mld->mld_maxdelay);    /* in 1/10ths of a second */
  834         if (maxdelay >= 32768) {
  835                 maxdelay = (MLD_MRC_MANT(maxdelay) | 0x1000) <<
  836                            (MLD_MRC_EXP(maxdelay) + 3);
  837         }
  838         timer = (maxdelay * PR_FASTHZ) / MLD_TIMER_SCALE;
  839         if (timer == 0)
  840                 timer = 1;
  841 
  842         qrv = MLD_QRV(mld->mld_misc);
  843         if (qrv < 2) {
  844                 CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
  845                     qrv, MLD_RV_INIT);
  846                 qrv = MLD_RV_INIT;
  847         }
  848 
  849         qqi = mld->mld_qqi;
  850         if (qqi >= 128) {
  851                 qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
  852                      (MLD_QQIC_EXP(mld->mld_qqi) + 3);
  853         }
  854 
  855         nsrc = ntohs(mld->mld_numsrc);
  856         if (nsrc > MLD_MAX_GS_SOURCES)
  857                 return (EMSGSIZE);
  858         if (icmp6len < sizeof(struct mldv2_query) +
  859             (nsrc * sizeof(struct in6_addr)))
  860                 return (EMSGSIZE);
  861 
  862         /*
  863          * Do further input validation upfront to avoid resetting timers
  864          * should we need to discard this query.
  865          */
  866         if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
  867                 /*
  868                  * A general query with a source list has undefined
  869                  * behaviour; discard it.
  870                  */
  871                 if (nsrc > 0)
  872                         return (EINVAL);
  873                 is_general_query = 1;
  874         } else {
  875                 /*
  876                  * Embed scope ID of receiving interface in MLD query for
  877                  * lookup whilst we don't hold other locks (due to KAME
  878                  * locking lameness). We own this mbuf chain just now.
  879                  */
  880                 in6_setscope(&mld->mld_addr, ifp, NULL);
  881         }
  882 
  883         IN6_MULTI_LOCK();
  884         MLD_LOCK();
  885 
  886         mli = MLD_IFINFO(ifp);
  887         KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
  888 
  889         /*
  890          * Discard the v2 query if we're in Compatibility Mode.
  891          * The RFC is pretty clear that hosts need to stay in MLDv1 mode
  892          * until the Old Version Querier Present timer expires.
  893          */
  894         if (mli->mli_version != MLD_VERSION_2)
  895                 goto out_locked;
  896 
  897         mld_set_version(mli, MLD_VERSION_2);
  898         mli->mli_rv = qrv;
  899         mli->mli_qi = qqi;
  900         mli->mli_qri = maxdelay;
  901 
  902         CTR4(KTR_MLD, "%s: qrv %d qi %d maxdelay %d", __func__, qrv, qqi,
  903             maxdelay);
  904 
  905         if (is_general_query) {
  906                 /*
  907                  * MLDv2 General Query.
  908                  *
  909                  * Schedule a current-state report on this ifp for
  910                  * all groups, possibly containing source lists.
  911                  *
  912                  * If there is a pending General Query response
  913                  * scheduled earlier than the selected delay, do
  914                  * not schedule any other reports.
  915                  * Otherwise, reset the interface timer.
  916                  */
  917                 CTR2(KTR_MLD, "process v2 general query on ifp %p(%s)",
  918                     ifp, if_name(ifp));
  919                 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer) {
  920                         mli->mli_v2_timer = MLD_RANDOM_DELAY(timer);
  921                         V_interface_timers_running6 = 1;
  922                 }
  923         } else {
  924                 /*
  925                  * MLDv2 Group-specific or Group-and-source-specific Query.
  926                  *
  927                  * Group-source-specific queries are throttled on
  928                  * a per-group basis to defeat denial-of-service attempts.
  929                  * Queries for groups we are not a member of on this
  930                  * link are simply ignored.
  931                  */
  932                 IF_ADDR_RLOCK(ifp);
  933                 inm = in6m_lookup_locked(ifp, &mld->mld_addr);
  934                 if (inm == NULL) {
  935                         IF_ADDR_RUNLOCK(ifp);
  936                         goto out_locked;
  937                 }
  938                 if (nsrc > 0) {
  939                         if (!ratecheck(&inm->in6m_lastgsrtv,
  940                             &V_mld_gsrdelay)) {
  941                                 CTR1(KTR_MLD, "%s: GS query throttled.",
  942                                     __func__);
  943                                 IF_ADDR_RUNLOCK(ifp);
  944                                 goto out_locked;
  945                         }
  946                 }
  947                 CTR2(KTR_MLD, "process v2 group query on ifp %p(%s)",
  948                      ifp, if_name(ifp));
  949                 /*
  950                  * If there is a pending General Query response
  951                  * scheduled sooner than the selected delay, no
  952                  * further report need be scheduled.
  953                  * Otherwise, prepare to respond to the
  954                  * group-specific or group-and-source query.
  955                  */
  956                 if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer)
  957                         mld_v2_process_group_query(inm, mli, timer, m, off);
  958 
  959                 /* XXX Clear embedded scope ID as userland won't expect it. */
  960                 in6_clearscope(&mld->mld_addr);
  961                 IF_ADDR_RUNLOCK(ifp);
  962         }
  963 
  964 out_locked:
  965         MLD_UNLOCK();
  966         IN6_MULTI_UNLOCK();
  967 
  968         return (0);
  969 }
  970 
  971 /*
  972  * Process a received MLDv2 group-specific or group-and-source-specific
  973  * query.
  974  * Return <0 if any error occurred. Currently this is ignored.
  975  */
  976 static int
  977 mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifsoftc *mli,
  978     int timer, struct mbuf *m0, const int off)
  979 {
  980         struct mldv2_query      *mld;
  981         int                      retval;
  982         uint16_t                 nsrc;
  983 
  984         IN6_MULTI_LOCK_ASSERT();
  985         MLD_LOCK_ASSERT();
  986 
  987         retval = 0;
  988         mld = (struct mldv2_query *)(mtod(m0, uint8_t *) + off);
  989 
  990         switch (inm->in6m_state) {
  991         case MLD_NOT_MEMBER:
  992         case MLD_SILENT_MEMBER:
  993         case MLD_SLEEPING_MEMBER:
  994         case MLD_LAZY_MEMBER:
  995         case MLD_AWAKENING_MEMBER:
  996         case MLD_IDLE_MEMBER:
  997         case MLD_LEAVING_MEMBER:
  998                 return (retval);
  999                 break;
 1000         case MLD_REPORTING_MEMBER:
 1001         case MLD_G_QUERY_PENDING_MEMBER:
 1002         case MLD_SG_QUERY_PENDING_MEMBER:
 1003                 break;
 1004         }
 1005 
 1006         nsrc = ntohs(mld->mld_numsrc);
 1007 
 1008         /*
 1009          * Deal with group-specific queries upfront.
 1010          * If any group query is already pending, purge any recorded
 1011          * source-list state if it exists, and schedule a query response
 1012          * for this group-specific query.
 1013          */
 1014         if (nsrc == 0) {
 1015                 if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
 1016                     inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER) {
 1017                         in6m_clear_recorded(inm);
 1018                         timer = min(inm->in6m_timer, timer);
 1019                 }
 1020                 inm->in6m_state = MLD_G_QUERY_PENDING_MEMBER;
 1021                 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
 1022                 V_current_state_timers_running6 = 1;
 1023                 return (retval);
 1024         }
 1025 
 1026         /*
 1027          * Deal with the case where a group-and-source-specific query has
 1028          * been received but a group-specific query is already pending.
 1029          */
 1030         if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER) {
 1031                 timer = min(inm->in6m_timer, timer);
 1032                 inm->in6m_timer = MLD_RANDOM_DELAY(timer);
 1033                 V_current_state_timers_running6 = 1;
 1034                 return (retval);
 1035         }
 1036 
 1037         /*
 1038          * Finally, deal with the case where a group-and-source-specific
 1039          * query has been received, where a response to a previous g-s-r
 1040          * query exists, or none exists.
 1041          * In this case, we need to parse the source-list which the Querier
 1042          * has provided us with and check if we have any source list filter
 1043          * entries at T1 for these sources. If we do not, there is no need
 1044          * schedule a report and the query may be dropped.
 1045          * If we do, we must record them and schedule a current-state
 1046          * report for those sources.
 1047          */
 1048         if (inm->in6m_nsrc > 0) {
 1049                 struct mbuf             *m;
 1050                 uint8_t                 *sp;
 1051                 int                      i, nrecorded;
 1052                 int                      soff;
 1053 
 1054                 m = m0;
 1055                 soff = off + sizeof(struct mldv2_query);
 1056                 nrecorded = 0;
 1057                 for (i = 0; i < nsrc; i++) {
 1058                         sp = mtod(m, uint8_t *) + soff;
 1059                         retval = in6m_record_source(inm,
 1060                             (const struct in6_addr *)sp);
 1061                         if (retval < 0)
 1062                                 break;
 1063                         nrecorded += retval;
 1064                         soff += sizeof(struct in6_addr);
 1065                         if (soff >= m->m_len) {
 1066                                 soff = soff - m->m_len;
 1067                                 m = m->m_next;
 1068                                 if (m == NULL)
 1069                                         break;
 1070                         }
 1071                 }
 1072                 if (nrecorded > 0) {
 1073                         CTR1(KTR_MLD,
 1074                             "%s: schedule response to SG query", __func__);
 1075                         inm->in6m_state = MLD_SG_QUERY_PENDING_MEMBER;
 1076                         inm->in6m_timer = MLD_RANDOM_DELAY(timer);
 1077                         V_current_state_timers_running6 = 1;
 1078                 }
 1079         }
 1080 
 1081         return (retval);
 1082 }
 1083 
 1084 /*
 1085  * Process a received MLDv1 host membership report.
 1086  * Assumes mld points to mld_hdr in pulled up mbuf chain.
 1087  *
 1088  * NOTE: Can't be fully const correct as we temporarily embed scope ID in
 1089  * mld_addr. This is OK as we own the mbuf chain.
 1090  */
 1091 static int
 1092 mld_v1_input_report(struct ifnet *ifp, const struct ip6_hdr *ip6,
 1093     /*const*/ struct mld_hdr *mld)
 1094 {
 1095         struct in6_addr          src, dst;
 1096         struct in6_ifaddr       *ia;
 1097         struct in6_multi        *inm;
 1098 #ifdef KTR
 1099         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1100 #endif
 1101 
 1102         if (!mld_v1enable) {
 1103                 CTR3(KTR_MLD, "ignore v1 report %s on ifp %p(%s)",
 1104                     ip6_sprintf(ip6tbuf, &mld->mld_addr),
 1105                     ifp, if_name(ifp));
 1106                 return (0);
 1107         }
 1108 
 1109         if (ifp->if_flags & IFF_LOOPBACK)
 1110                 return (0);
 1111 
 1112         /*
 1113          * MLDv1 reports must originate from a host's link-local address,
 1114          * or the unspecified address (when booting).
 1115          */
 1116         src = ip6->ip6_src;
 1117         in6_clearscope(&src);
 1118         if (!IN6_IS_SCOPE_LINKLOCAL(&src) && !IN6_IS_ADDR_UNSPECIFIED(&src)) {
 1119                 CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
 1120                     ip6_sprintf(ip6tbuf, &ip6->ip6_src),
 1121                     ifp, if_name(ifp));
 1122                 return (EINVAL);
 1123         }
 1124 
 1125         /*
 1126          * RFC2710 Section 4: MLDv1 reports must pertain to a multicast
 1127          * group, and must be directed to the group itself.
 1128          */
 1129         dst = ip6->ip6_dst;
 1130         in6_clearscope(&dst);
 1131         if (!IN6_IS_ADDR_MULTICAST(&mld->mld_addr) ||
 1132             !IN6_ARE_ADDR_EQUAL(&mld->mld_addr, &dst)) {
 1133                 CTR3(KTR_MLD, "ignore v1 query dst %s on ifp %p(%s)",
 1134                     ip6_sprintf(ip6tbuf, &ip6->ip6_dst),
 1135                     ifp, if_name(ifp));
 1136                 return (EINVAL);
 1137         }
 1138 
 1139         /*
 1140          * Make sure we don't hear our own membership report, as fast
 1141          * leave requires knowing that we are the only member of a
 1142          * group. Assume we used the link-local address if available,
 1143          * otherwise look for ::.
 1144          *
 1145          * XXX Note that scope ID comparison is needed for the address
 1146          * returned by in6ifa_ifpforlinklocal(), but SHOULD NOT be
 1147          * performed for the on-wire address.
 1148          */
 1149         ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
 1150         if ((ia && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, IA6_IN6(ia))) ||
 1151             (ia == NULL && IN6_IS_ADDR_UNSPECIFIED(&src))) {
 1152                 if (ia != NULL)
 1153                         ifa_free(&ia->ia_ifa);
 1154                 return (0);
 1155         }
 1156         if (ia != NULL)
 1157                 ifa_free(&ia->ia_ifa);
 1158 
 1159         CTR3(KTR_MLD, "process v1 report %s on ifp %p(%s)",
 1160             ip6_sprintf(ip6tbuf, &mld->mld_addr), ifp, if_name(ifp));
 1161 
 1162         /*
 1163          * Embed scope ID of receiving interface in MLD query for lookup
 1164          * whilst we don't hold other locks (due to KAME locking lameness).
 1165          */
 1166         if (!IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr))
 1167                 in6_setscope(&mld->mld_addr, ifp, NULL);
 1168 
 1169         IN6_MULTI_LOCK();
 1170         MLD_LOCK();
 1171         IF_ADDR_RLOCK(ifp);
 1172 
 1173         /*
 1174          * MLDv1 report suppression.
 1175          * If we are a member of this group, and our membership should be
 1176          * reported, and our group timer is pending or about to be reset,
 1177          * stop our group timer by transitioning to the 'lazy' state.
 1178          */
 1179         inm = in6m_lookup_locked(ifp, &mld->mld_addr);
 1180         if (inm != NULL) {
 1181                 struct mld_ifsoftc *mli;
 1182 
 1183                 mli = inm->in6m_mli;
 1184                 KASSERT(mli != NULL,
 1185                     ("%s: no mli for ifp %p", __func__, ifp));
 1186 
 1187                 /*
 1188                  * If we are in MLDv2 host mode, do not allow the
 1189                  * other host's MLDv1 report to suppress our reports.
 1190                  */
 1191                 if (mli->mli_version == MLD_VERSION_2)
 1192                         goto out_locked;
 1193 
 1194                 inm->in6m_timer = 0;
 1195 
 1196                 switch (inm->in6m_state) {
 1197                 case MLD_NOT_MEMBER:
 1198                 case MLD_SILENT_MEMBER:
 1199                 case MLD_SLEEPING_MEMBER:
 1200                         break;
 1201                 case MLD_REPORTING_MEMBER:
 1202                 case MLD_IDLE_MEMBER:
 1203                 case MLD_AWAKENING_MEMBER:
 1204                         CTR3(KTR_MLD,
 1205                             "report suppressed for %s on ifp %p(%s)",
 1206                             ip6_sprintf(ip6tbuf, &mld->mld_addr),
 1207                             ifp, if_name(ifp));
 1208                 case MLD_LAZY_MEMBER:
 1209                         inm->in6m_state = MLD_LAZY_MEMBER;
 1210                         break;
 1211                 case MLD_G_QUERY_PENDING_MEMBER:
 1212                 case MLD_SG_QUERY_PENDING_MEMBER:
 1213                 case MLD_LEAVING_MEMBER:
 1214                         break;
 1215                 }
 1216         }
 1217 
 1218 out_locked:
 1219         IF_ADDR_RUNLOCK(ifp);
 1220         MLD_UNLOCK();
 1221         IN6_MULTI_UNLOCK();
 1222 
 1223         /* XXX Clear embedded scope ID as userland won't expect it. */
 1224         in6_clearscope(&mld->mld_addr);
 1225 
 1226         return (0);
 1227 }
 1228 
 1229 /*
 1230  * MLD input path.
 1231  *
 1232  * Assume query messages which fit in a single ICMPv6 message header
 1233  * have been pulled up.
 1234  * Assume that userland will want to see the message, even if it
 1235  * otherwise fails kernel input validation; do not free it.
 1236  * Pullup may however free the mbuf chain m if it fails.
 1237  *
 1238  * Return IPPROTO_DONE if we freed m. Otherwise, return 0.
 1239  */
 1240 int
 1241 mld_input(struct mbuf *m, int off, int icmp6len)
 1242 {
 1243         struct ifnet    *ifp;
 1244         struct ip6_hdr  *ip6;
 1245         struct mld_hdr  *mld;
 1246         int              mldlen;
 1247 
 1248         CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
 1249 
 1250         ifp = m->m_pkthdr.rcvif;
 1251 
 1252         ip6 = mtod(m, struct ip6_hdr *);
 1253 
 1254         /* Pullup to appropriate size. */
 1255         mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
 1256         if (mld->mld_type == MLD_LISTENER_QUERY &&
 1257             icmp6len >= sizeof(struct mldv2_query)) {
 1258                 mldlen = sizeof(struct mldv2_query);
 1259         } else {
 1260                 mldlen = sizeof(struct mld_hdr);
 1261         }
 1262         IP6_EXTHDR_GET(mld, struct mld_hdr *, m, off, mldlen);
 1263         if (mld == NULL) {
 1264                 ICMP6STAT_INC(icp6s_badlen);
 1265                 return (IPPROTO_DONE);
 1266         }
 1267 
 1268         /*
 1269          * Userland needs to see all of this traffic for implementing
 1270          * the endpoint discovery portion of multicast routing.
 1271          */
 1272         switch (mld->mld_type) {
 1273         case MLD_LISTENER_QUERY:
 1274                 icmp6_ifstat_inc(ifp, ifs6_in_mldquery);
 1275                 if (icmp6len == sizeof(struct mld_hdr)) {
 1276                         if (mld_v1_input_query(ifp, ip6, mld) != 0)
 1277                                 return (0);
 1278                 } else if (icmp6len >= sizeof(struct mldv2_query)) {
 1279                         if (mld_v2_input_query(ifp, ip6, m, off,
 1280                             icmp6len) != 0)
 1281                                 return (0);
 1282                 }
 1283                 break;
 1284         case MLD_LISTENER_REPORT:
 1285                 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
 1286                 if (mld_v1_input_report(ifp, ip6, mld) != 0)
 1287                         return (0);
 1288                 break;
 1289         case MLDV2_LISTENER_REPORT:
 1290                 icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
 1291                 break;
 1292         case MLD_LISTENER_DONE:
 1293                 icmp6_ifstat_inc(ifp, ifs6_in_mlddone);
 1294                 break;
 1295         default:
 1296                 break;
 1297         }
 1298 
 1299         return (0);
 1300 }
 1301 
 1302 /*
 1303  * Fast timeout handler (global).
 1304  * VIMAGE: Timeout handlers are expected to service all vimages.
 1305  */
 1306 void
 1307 mld_fasttimo(void)
 1308 {
 1309         VNET_ITERATOR_DECL(vnet_iter);
 1310 
 1311         VNET_LIST_RLOCK_NOSLEEP();
 1312         VNET_FOREACH(vnet_iter) {
 1313                 CURVNET_SET(vnet_iter);
 1314                 mld_fasttimo_vnet();
 1315                 CURVNET_RESTORE();
 1316         }
 1317         VNET_LIST_RUNLOCK_NOSLEEP();
 1318 }
 1319 
 1320 /*
 1321  * Fast timeout handler (per-vnet).
 1322  *
 1323  * VIMAGE: Assume caller has set up our curvnet.
 1324  */
 1325 static void
 1326 mld_fasttimo_vnet(void)
 1327 {
 1328         struct mbufq             scq;   /* State-change packets */
 1329         struct mbufq             qrq;   /* Query response packets */
 1330         struct ifnet            *ifp;
 1331         struct mld_ifsoftc      *mli;
 1332         struct ifmultiaddr      *ifma;
 1333         struct in6_multi        *inm, *tinm;
 1334         int                      uri_fasthz;
 1335 
 1336         uri_fasthz = 0;
 1337 
 1338         /*
 1339          * Quick check to see if any work needs to be done, in order to
 1340          * minimize the overhead of fasttimo processing.
 1341          * SMPng: XXX Unlocked reads.
 1342          */
 1343         if (!V_current_state_timers_running6 &&
 1344             !V_interface_timers_running6 &&
 1345             !V_state_change_timers_running6)
 1346                 return;
 1347 
 1348         IN6_MULTI_LOCK();
 1349         MLD_LOCK();
 1350 
 1351         /*
 1352          * MLDv2 General Query response timer processing.
 1353          */
 1354         if (V_interface_timers_running6) {
 1355                 CTR1(KTR_MLD, "%s: interface timers running", __func__);
 1356 
 1357                 V_interface_timers_running6 = 0;
 1358                 LIST_FOREACH(mli, &V_mli_head, mli_link) {
 1359                         if (mli->mli_v2_timer == 0) {
 1360                                 /* Do nothing. */
 1361                         } else if (--mli->mli_v2_timer == 0) {
 1362                                 mld_v2_dispatch_general_query(mli);
 1363                         } else {
 1364                                 V_interface_timers_running6 = 1;
 1365                         }
 1366                 }
 1367         }
 1368 
 1369         if (!V_current_state_timers_running6 &&
 1370             !V_state_change_timers_running6)
 1371                 goto out_locked;
 1372 
 1373         V_current_state_timers_running6 = 0;
 1374         V_state_change_timers_running6 = 0;
 1375 
 1376         CTR1(KTR_MLD, "%s: state change timers running", __func__);
 1377 
 1378         /*
 1379          * MLD host report and state-change timer processing.
 1380          * Note: Processing a v2 group timer may remove a node.
 1381          */
 1382         LIST_FOREACH(mli, &V_mli_head, mli_link) {
 1383                 ifp = mli->mli_ifp;
 1384 
 1385                 if (mli->mli_version == MLD_VERSION_2) {
 1386                         uri_fasthz = MLD_RANDOM_DELAY(mli->mli_uri *
 1387                             PR_FASTHZ);
 1388                         mbufq_init(&qrq, MLD_MAX_G_GS_PACKETS);
 1389                         mbufq_init(&scq, MLD_MAX_STATE_CHANGE_PACKETS);
 1390                 }
 1391 
 1392                 IF_ADDR_RLOCK(ifp);
 1393                 TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
 1394                         if (ifma->ifma_addr->sa_family != AF_INET6 ||
 1395                             ifma->ifma_protospec == NULL)
 1396                                 continue;
 1397                         inm = (struct in6_multi *)ifma->ifma_protospec;
 1398                         switch (mli->mli_version) {
 1399                         case MLD_VERSION_1:
 1400                                 mld_v1_process_group_timer(mli, inm);
 1401                                 break;
 1402                         case MLD_VERSION_2:
 1403                                 mld_v2_process_group_timers(mli, &qrq,
 1404                                     &scq, inm, uri_fasthz);
 1405                                 break;
 1406                         }
 1407                 }
 1408                 IF_ADDR_RUNLOCK(ifp);
 1409 
 1410                 switch (mli->mli_version) {
 1411                 case MLD_VERSION_1:
 1412                         /*
 1413                          * Transmit reports for this lifecycle.  This
 1414                          * is done while not holding IF_ADDR_LOCK
 1415                          * since this can call
 1416                          * in6ifa_ifpforlinklocal() which locks
 1417                          * IF_ADDR_LOCK internally as well as
 1418                          * ip6_output() to transmit a packet.
 1419                          */
 1420                         SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead,
 1421                             in6m_nrele, tinm) {
 1422                                 SLIST_REMOVE_HEAD(&mli->mli_relinmhead,
 1423                                     in6m_nrele);
 1424                                 (void)mld_v1_transmit_report(inm,
 1425                                     MLD_LISTENER_REPORT);
 1426                         }
 1427                         break;
 1428                 case MLD_VERSION_2:
 1429                         mld_dispatch_queue(&qrq, 0);
 1430                         mld_dispatch_queue(&scq, 0);
 1431 
 1432                         /*
 1433                          * Free the in_multi reference(s) for
 1434                          * this lifecycle.
 1435                          */
 1436                         SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead,
 1437                             in6m_nrele, tinm) {
 1438                                 SLIST_REMOVE_HEAD(&mli->mli_relinmhead,
 1439                                     in6m_nrele);
 1440                                 in6m_release_locked(inm);
 1441                         }
 1442                         break;
 1443                 }
 1444         }
 1445 
 1446 out_locked:
 1447         MLD_UNLOCK();
 1448         IN6_MULTI_UNLOCK();
 1449 }
 1450 
 1451 /*
 1452  * Update host report group timer.
 1453  * Will update the global pending timer flags.
 1454  */
 1455 static void
 1456 mld_v1_process_group_timer(struct mld_ifsoftc *mli, struct in6_multi *inm)
 1457 {
 1458         int report_timer_expired;
 1459 
 1460         IN6_MULTI_LOCK_ASSERT();
 1461         MLD_LOCK_ASSERT();
 1462 
 1463         if (inm->in6m_timer == 0) {
 1464                 report_timer_expired = 0;
 1465         } else if (--inm->in6m_timer == 0) {
 1466                 report_timer_expired = 1;
 1467         } else {
 1468                 V_current_state_timers_running6 = 1;
 1469                 return;
 1470         }
 1471 
 1472         switch (inm->in6m_state) {
 1473         case MLD_NOT_MEMBER:
 1474         case MLD_SILENT_MEMBER:
 1475         case MLD_IDLE_MEMBER:
 1476         case MLD_LAZY_MEMBER:
 1477         case MLD_SLEEPING_MEMBER:
 1478         case MLD_AWAKENING_MEMBER:
 1479                 break;
 1480         case MLD_REPORTING_MEMBER:
 1481                 if (report_timer_expired) {
 1482                         inm->in6m_state = MLD_IDLE_MEMBER;
 1483                         SLIST_INSERT_HEAD(&mli->mli_relinmhead, inm,
 1484                             in6m_nrele);
 1485                 }
 1486                 break;
 1487         case MLD_G_QUERY_PENDING_MEMBER:
 1488         case MLD_SG_QUERY_PENDING_MEMBER:
 1489         case MLD_LEAVING_MEMBER:
 1490                 break;
 1491         }
 1492 }
 1493 
 1494 /*
 1495  * Update a group's timers for MLDv2.
 1496  * Will update the global pending timer flags.
 1497  * Note: Unlocked read from mli.
 1498  */
 1499 static void
 1500 mld_v2_process_group_timers(struct mld_ifsoftc *mli,
 1501     struct mbufq *qrq, struct mbufq *scq,
 1502     struct in6_multi *inm, const int uri_fasthz)
 1503 {
 1504         int query_response_timer_expired;
 1505         int state_change_retransmit_timer_expired;
 1506 #ifdef KTR
 1507         char ip6tbuf[INET6_ADDRSTRLEN];
 1508 #endif
 1509 
 1510         IN6_MULTI_LOCK_ASSERT();
 1511         MLD_LOCK_ASSERT();
 1512 
 1513         query_response_timer_expired = 0;
 1514         state_change_retransmit_timer_expired = 0;
 1515 
 1516         /*
 1517          * During a transition from compatibility mode back to MLDv2,
 1518          * a group record in REPORTING state may still have its group
 1519          * timer active. This is a no-op in this function; it is easier
 1520          * to deal with it here than to complicate the slow-timeout path.
 1521          */
 1522         if (inm->in6m_timer == 0) {
 1523                 query_response_timer_expired = 0;
 1524         } else if (--inm->in6m_timer == 0) {
 1525                 query_response_timer_expired = 1;
 1526         } else {
 1527                 V_current_state_timers_running6 = 1;
 1528         }
 1529 
 1530         if (inm->in6m_sctimer == 0) {
 1531                 state_change_retransmit_timer_expired = 0;
 1532         } else if (--inm->in6m_sctimer == 0) {
 1533                 state_change_retransmit_timer_expired = 1;
 1534         } else {
 1535                 V_state_change_timers_running6 = 1;
 1536         }
 1537 
 1538         /* We are in fasttimo, so be quick about it. */
 1539         if (!state_change_retransmit_timer_expired &&
 1540             !query_response_timer_expired)
 1541                 return;
 1542 
 1543         switch (inm->in6m_state) {
 1544         case MLD_NOT_MEMBER:
 1545         case MLD_SILENT_MEMBER:
 1546         case MLD_SLEEPING_MEMBER:
 1547         case MLD_LAZY_MEMBER:
 1548         case MLD_AWAKENING_MEMBER:
 1549         case MLD_IDLE_MEMBER:
 1550                 break;
 1551         case MLD_G_QUERY_PENDING_MEMBER:
 1552         case MLD_SG_QUERY_PENDING_MEMBER:
 1553                 /*
 1554                  * Respond to a previously pending Group-Specific
 1555                  * or Group-and-Source-Specific query by enqueueing
 1556                  * the appropriate Current-State report for
 1557                  * immediate transmission.
 1558                  */
 1559                 if (query_response_timer_expired) {
 1560                         int retval;
 1561 
 1562                         retval = mld_v2_enqueue_group_record(qrq, inm, 0, 1,
 1563                             (inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER),
 1564                             0);
 1565                         CTR2(KTR_MLD, "%s: enqueue record = %d",
 1566                             __func__, retval);
 1567                         inm->in6m_state = MLD_REPORTING_MEMBER;
 1568                         in6m_clear_recorded(inm);
 1569                 }
 1570                 /* FALLTHROUGH */
 1571         case MLD_REPORTING_MEMBER:
 1572         case MLD_LEAVING_MEMBER:
 1573                 if (state_change_retransmit_timer_expired) {
 1574                         /*
 1575                          * State-change retransmission timer fired.
 1576                          * If there are any further pending retransmissions,
 1577                          * set the global pending state-change flag, and
 1578                          * reset the timer.
 1579                          */
 1580                         if (--inm->in6m_scrv > 0) {
 1581                                 inm->in6m_sctimer = uri_fasthz;
 1582                                 V_state_change_timers_running6 = 1;
 1583                         }
 1584                         /*
 1585                          * Retransmit the previously computed state-change
 1586                          * report. If there are no further pending
 1587                          * retransmissions, the mbuf queue will be consumed.
 1588                          * Update T0 state to T1 as we have now sent
 1589                          * a state-change.
 1590                          */
 1591                         (void)mld_v2_merge_state_changes(inm, scq);
 1592 
 1593                         in6m_commit(inm);
 1594                         CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
 1595                             ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 1596                             if_name(inm->in6m_ifp));
 1597 
 1598                         /*
 1599                          * If we are leaving the group for good, make sure
 1600                          * we release MLD's reference to it.
 1601                          * This release must be deferred using a SLIST,
 1602                          * as we are called from a loop which traverses
 1603                          * the in_ifmultiaddr TAILQ.
 1604                          */
 1605                         if (inm->in6m_state == MLD_LEAVING_MEMBER &&
 1606                             inm->in6m_scrv == 0) {
 1607                                 inm->in6m_state = MLD_NOT_MEMBER;
 1608                                 SLIST_INSERT_HEAD(&mli->mli_relinmhead,
 1609                                     inm, in6m_nrele);
 1610                         }
 1611                 }
 1612                 break;
 1613         }
 1614 }
 1615 
 1616 /*
 1617  * Switch to a different version on the given interface,
 1618  * as per Section 9.12.
 1619  */
 1620 static void
 1621 mld_set_version(struct mld_ifsoftc *mli, const int version)
 1622 {
 1623         int old_version_timer;
 1624 
 1625         MLD_LOCK_ASSERT();
 1626 
 1627         CTR4(KTR_MLD, "%s: switching to v%d on ifp %p(%s)", __func__,
 1628             version, mli->mli_ifp, if_name(mli->mli_ifp));
 1629 
 1630         if (version == MLD_VERSION_1) {
 1631                 /*
 1632                  * Compute the "Older Version Querier Present" timer as per
 1633                  * Section 9.12.
 1634                  */
 1635                 old_version_timer = (mli->mli_rv * mli->mli_qi) + mli->mli_qri;
 1636                 old_version_timer *= PR_SLOWHZ;
 1637                 mli->mli_v1_timer = old_version_timer;
 1638         }
 1639 
 1640         if (mli->mli_v1_timer > 0 && mli->mli_version != MLD_VERSION_1) {
 1641                 mli->mli_version = MLD_VERSION_1;
 1642                 mld_v2_cancel_link_timers(mli);
 1643         }
 1644 }
 1645 
 1646 /*
 1647  * Cancel pending MLDv2 timers for the given link and all groups
 1648  * joined on it; state-change, general-query, and group-query timers.
 1649  */
 1650 static void
 1651 mld_v2_cancel_link_timers(struct mld_ifsoftc *mli)
 1652 {
 1653         struct ifmultiaddr      *ifma;
 1654         struct ifnet            *ifp;
 1655         struct in6_multi        *inm, *tinm;
 1656 
 1657         CTR3(KTR_MLD, "%s: cancel v2 timers on ifp %p(%s)", __func__,
 1658             mli->mli_ifp, if_name(mli->mli_ifp));
 1659 
 1660         IN6_MULTI_LOCK_ASSERT();
 1661         MLD_LOCK_ASSERT();
 1662 
 1663         /*
 1664          * Fast-track this potentially expensive operation
 1665          * by checking all the global 'timer pending' flags.
 1666          */
 1667         if (!V_interface_timers_running6 &&
 1668             !V_state_change_timers_running6 &&
 1669             !V_current_state_timers_running6)
 1670                 return;
 1671 
 1672         mli->mli_v2_timer = 0;
 1673 
 1674         ifp = mli->mli_ifp;
 1675 
 1676         IF_ADDR_RLOCK(ifp);
 1677         TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
 1678                 if (ifma->ifma_addr->sa_family != AF_INET6)
 1679                         continue;
 1680                 inm = (struct in6_multi *)ifma->ifma_protospec;
 1681                 switch (inm->in6m_state) {
 1682                 case MLD_NOT_MEMBER:
 1683                 case MLD_SILENT_MEMBER:
 1684                 case MLD_IDLE_MEMBER:
 1685                 case MLD_LAZY_MEMBER:
 1686                 case MLD_SLEEPING_MEMBER:
 1687                 case MLD_AWAKENING_MEMBER:
 1688                         break;
 1689                 case MLD_LEAVING_MEMBER:
 1690                         /*
 1691                          * If we are leaving the group and switching
 1692                          * version, we need to release the final
 1693                          * reference held for issuing the INCLUDE {}.
 1694                          */
 1695                         SLIST_INSERT_HEAD(&mli->mli_relinmhead, inm,
 1696                             in6m_nrele);
 1697                         /* FALLTHROUGH */
 1698                 case MLD_G_QUERY_PENDING_MEMBER:
 1699                 case MLD_SG_QUERY_PENDING_MEMBER:
 1700                         in6m_clear_recorded(inm);
 1701                         /* FALLTHROUGH */
 1702                 case MLD_REPORTING_MEMBER:
 1703                         inm->in6m_sctimer = 0;
 1704                         inm->in6m_timer = 0;
 1705                         inm->in6m_state = MLD_REPORTING_MEMBER;
 1706                         /*
 1707                          * Free any pending MLDv2 state-change records.
 1708                          */
 1709                         mbufq_drain(&inm->in6m_scq);
 1710                         break;
 1711                 }
 1712         }
 1713         IF_ADDR_RUNLOCK(ifp);
 1714         SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead, in6m_nrele, tinm) {
 1715                 SLIST_REMOVE_HEAD(&mli->mli_relinmhead, in6m_nrele);
 1716                 in6m_release_locked(inm);
 1717         }
 1718 }
 1719 
 1720 /*
 1721  * Global slowtimo handler.
 1722  * VIMAGE: Timeout handlers are expected to service all vimages.
 1723  */
 1724 void
 1725 mld_slowtimo(void)
 1726 {
 1727         VNET_ITERATOR_DECL(vnet_iter);
 1728 
 1729         VNET_LIST_RLOCK_NOSLEEP();
 1730         VNET_FOREACH(vnet_iter) {
 1731                 CURVNET_SET(vnet_iter);
 1732                 mld_slowtimo_vnet();
 1733                 CURVNET_RESTORE();
 1734         }
 1735         VNET_LIST_RUNLOCK_NOSLEEP();
 1736 }
 1737 
 1738 /*
 1739  * Per-vnet slowtimo handler.
 1740  */
 1741 static void
 1742 mld_slowtimo_vnet(void)
 1743 {
 1744         struct mld_ifsoftc *mli;
 1745 
 1746         MLD_LOCK();
 1747 
 1748         LIST_FOREACH(mli, &V_mli_head, mli_link) {
 1749                 mld_v1_process_querier_timers(mli);
 1750         }
 1751 
 1752         MLD_UNLOCK();
 1753 }
 1754 
 1755 /*
 1756  * Update the Older Version Querier Present timers for a link.
 1757  * See Section 9.12 of RFC 3810.
 1758  */
 1759 static void
 1760 mld_v1_process_querier_timers(struct mld_ifsoftc *mli)
 1761 {
 1762 
 1763         MLD_LOCK_ASSERT();
 1764 
 1765         if (mli->mli_version != MLD_VERSION_2 && --mli->mli_v1_timer == 0) {
 1766                 /*
 1767                  * MLDv1 Querier Present timer expired; revert to MLDv2.
 1768                  */
 1769                 CTR5(KTR_MLD,
 1770                     "%s: transition from v%d -> v%d on %p(%s)",
 1771                     __func__, mli->mli_version, MLD_VERSION_2,
 1772                     mli->mli_ifp, if_name(mli->mli_ifp));
 1773                 mli->mli_version = MLD_VERSION_2;
 1774         }
 1775 }
 1776 
 1777 /*
 1778  * Transmit an MLDv1 report immediately.
 1779  */
 1780 static int
 1781 mld_v1_transmit_report(struct in6_multi *in6m, const int type)
 1782 {
 1783         struct ifnet            *ifp;
 1784         struct in6_ifaddr       *ia;
 1785         struct ip6_hdr          *ip6;
 1786         struct mbuf             *mh, *md;
 1787         struct mld_hdr          *mld;
 1788 
 1789         IN6_MULTI_LOCK_ASSERT();
 1790         MLD_LOCK_ASSERT();
 1791 
 1792         ifp = in6m->in6m_ifp;
 1793         ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
 1794         /* ia may be NULL if link-local address is tentative. */
 1795 
 1796         mh = m_gethdr(M_NOWAIT, MT_DATA);
 1797         if (mh == NULL) {
 1798                 if (ia != NULL)
 1799                         ifa_free(&ia->ia_ifa);
 1800                 return (ENOMEM);
 1801         }
 1802         md = m_get(M_NOWAIT, MT_DATA);
 1803         if (md == NULL) {
 1804                 m_free(mh);
 1805                 if (ia != NULL)
 1806                         ifa_free(&ia->ia_ifa);
 1807                 return (ENOMEM);
 1808         }
 1809         mh->m_next = md;
 1810 
 1811         /*
 1812          * FUTURE: Consider increasing alignment by ETHER_HDR_LEN, so
 1813          * that ether_output() does not need to allocate another mbuf
 1814          * for the header in the most common case.
 1815          */
 1816         M_ALIGN(mh, sizeof(struct ip6_hdr));
 1817         mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
 1818         mh->m_len = sizeof(struct ip6_hdr);
 1819 
 1820         ip6 = mtod(mh, struct ip6_hdr *);
 1821         ip6->ip6_flow = 0;
 1822         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 1823         ip6->ip6_vfc |= IPV6_VERSION;
 1824         ip6->ip6_nxt = IPPROTO_ICMPV6;
 1825         ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
 1826         ip6->ip6_dst = in6m->in6m_addr;
 1827 
 1828         md->m_len = sizeof(struct mld_hdr);
 1829         mld = mtod(md, struct mld_hdr *);
 1830         mld->mld_type = type;
 1831         mld->mld_code = 0;
 1832         mld->mld_cksum = 0;
 1833         mld->mld_maxdelay = 0;
 1834         mld->mld_reserved = 0;
 1835         mld->mld_addr = in6m->in6m_addr;
 1836         in6_clearscope(&mld->mld_addr);
 1837         mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
 1838             sizeof(struct ip6_hdr), sizeof(struct mld_hdr));
 1839 
 1840         mld_save_context(mh, ifp);
 1841         mh->m_flags |= M_MLDV1;
 1842 
 1843         mld_dispatch_packet(mh);
 1844 
 1845         if (ia != NULL)
 1846                 ifa_free(&ia->ia_ifa);
 1847         return (0);
 1848 }
 1849 
 1850 /*
 1851  * Process a state change from the upper layer for the given IPv6 group.
 1852  *
 1853  * Each socket holds a reference on the in_multi in its own ip_moptions.
 1854  * The socket layer will have made the necessary updates to.the group
 1855  * state, it is now up to MLD to issue a state change report if there
 1856  * has been any change between T0 (when the last state-change was issued)
 1857  * and T1 (now).
 1858  *
 1859  * We use the MLDv2 state machine at group level. The MLd module
 1860  * however makes the decision as to which MLD protocol version to speak.
 1861  * A state change *from* INCLUDE {} always means an initial join.
 1862  * A state change *to* INCLUDE {} always means a final leave.
 1863  *
 1864  * If delay is non-zero, and the state change is an initial multicast
 1865  * join, the state change report will be delayed by 'delay' ticks
 1866  * in units of PR_FASTHZ if MLDv1 is active on the link; otherwise
 1867  * the initial MLDv2 state change report will be delayed by whichever
 1868  * is sooner, a pending state-change timer or delay itself.
 1869  *
 1870  * VIMAGE: curvnet should have been set by caller, as this routine
 1871  * is called from the socket option handlers.
 1872  */
 1873 int
 1874 mld_change_state(struct in6_multi *inm, const int delay)
 1875 {
 1876         struct mld_ifsoftc *mli;
 1877         struct ifnet *ifp;
 1878         int error;
 1879 
 1880         IN6_MULTI_LOCK_ASSERT();
 1881 
 1882         error = 0;
 1883 
 1884         /*
 1885          * Try to detect if the upper layer just asked us to change state
 1886          * for an interface which has now gone away.
 1887          */
 1888         KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
 1889         ifp = inm->in6m_ifma->ifma_ifp;
 1890         if (ifp != NULL) {
 1891                 /*
 1892                  * Sanity check that netinet6's notion of ifp is the
 1893                  * same as net's.
 1894                  */
 1895                 KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
 1896         }
 1897 
 1898         MLD_LOCK();
 1899 
 1900         mli = MLD_IFINFO(ifp);
 1901         KASSERT(mli != NULL, ("%s: no mld_ifsoftc for ifp %p", __func__, ifp));
 1902 
 1903         /*
 1904          * If we detect a state transition to or from MCAST_UNDEFINED
 1905          * for this group, then we are starting or finishing an MLD
 1906          * life cycle for this group.
 1907          */
 1908         if (inm->in6m_st[1].iss_fmode != inm->in6m_st[0].iss_fmode) {
 1909                 CTR3(KTR_MLD, "%s: inm transition %d -> %d", __func__,
 1910                     inm->in6m_st[0].iss_fmode, inm->in6m_st[1].iss_fmode);
 1911                 if (inm->in6m_st[0].iss_fmode == MCAST_UNDEFINED) {
 1912                         CTR1(KTR_MLD, "%s: initial join", __func__);
 1913                         error = mld_initial_join(inm, mli, delay);
 1914                         goto out_locked;
 1915                 } else if (inm->in6m_st[1].iss_fmode == MCAST_UNDEFINED) {
 1916                         CTR1(KTR_MLD, "%s: final leave", __func__);
 1917                         mld_final_leave(inm, mli);
 1918                         goto out_locked;
 1919                 }
 1920         } else {
 1921                 CTR1(KTR_MLD, "%s: filter set change", __func__);
 1922         }
 1923 
 1924         error = mld_handle_state_change(inm, mli);
 1925 
 1926 out_locked:
 1927         MLD_UNLOCK();
 1928         return (error);
 1929 }
 1930 
 1931 /*
 1932  * Perform the initial join for an MLD group.
 1933  *
 1934  * When joining a group:
 1935  *  If the group should have its MLD traffic suppressed, do nothing.
 1936  *  MLDv1 starts sending MLDv1 host membership reports.
 1937  *  MLDv2 will schedule an MLDv2 state-change report containing the
 1938  *  initial state of the membership.
 1939  *
 1940  * If the delay argument is non-zero, then we must delay sending the
 1941  * initial state change for delay ticks (in units of PR_FASTHZ).
 1942  */
 1943 static int
 1944 mld_initial_join(struct in6_multi *inm, struct mld_ifsoftc *mli,
 1945     const int delay)
 1946 {
 1947         struct ifnet            *ifp;
 1948         struct mbufq            *mq;
 1949         int                      error, retval, syncstates;
 1950         int                      odelay;
 1951 #ifdef KTR
 1952         char                     ip6tbuf[INET6_ADDRSTRLEN];
 1953 #endif
 1954 
 1955         CTR4(KTR_MLD, "%s: initial join %s on ifp %p(%s)",
 1956             __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 1957             inm->in6m_ifp, if_name(inm->in6m_ifp));
 1958 
 1959         error = 0;
 1960         syncstates = 1;
 1961 
 1962         ifp = inm->in6m_ifp;
 1963 
 1964         IN6_MULTI_LOCK_ASSERT();
 1965         MLD_LOCK_ASSERT();
 1966 
 1967         KASSERT(mli && mli->mli_ifp == ifp, ("%s: inconsistent ifp", __func__));
 1968 
 1969         /*
 1970          * Groups joined on loopback or marked as 'not reported',
 1971          * enter the MLD_SILENT_MEMBER state and
 1972          * are never reported in any protocol exchanges.
 1973          * All other groups enter the appropriate state machine
 1974          * for the version in use on this link.
 1975          * A link marked as MLIF_SILENT causes MLD to be completely
 1976          * disabled for the link.
 1977          */
 1978         if ((ifp->if_flags & IFF_LOOPBACK) ||
 1979             (mli->mli_flags & MLIF_SILENT) ||
 1980             !mld_is_addr_reported(&inm->in6m_addr)) {
 1981                 CTR1(KTR_MLD,
 1982 "%s: not kicking state machine for silent group", __func__);
 1983                 inm->in6m_state = MLD_SILENT_MEMBER;
 1984                 inm->in6m_timer = 0;
 1985         } else {
 1986                 /*
 1987                  * Deal with overlapping in_multi lifecycle.
 1988                  * If this group was LEAVING, then make sure
 1989                  * we drop the reference we picked up to keep the
 1990                  * group around for the final INCLUDE {} enqueue.
 1991                  */
 1992                 if (mli->mli_version == MLD_VERSION_2 &&
 1993                     inm->in6m_state == MLD_LEAVING_MEMBER)
 1994                         in6m_release_locked(inm);
 1995 
 1996                 inm->in6m_state = MLD_REPORTING_MEMBER;
 1997 
 1998                 switch (mli->mli_version) {
 1999                 case MLD_VERSION_1:
 2000                         /*
 2001                          * If a delay was provided, only use it if
 2002                          * it is greater than the delay normally
 2003                          * used for an MLDv1 state change report,
 2004                          * and delay sending the initial MLDv1 report
 2005                          * by not transitioning to the IDLE state.
 2006                          */
 2007                         odelay = MLD_RANDOM_DELAY(MLD_V1_MAX_RI * PR_FASTHZ);
 2008                         if (delay) {
 2009                                 inm->in6m_timer = max(delay, odelay);
 2010                                 V_current_state_timers_running6 = 1;
 2011                         } else {
 2012                                 inm->in6m_state = MLD_IDLE_MEMBER;
 2013                                 error = mld_v1_transmit_report(inm,
 2014                                      MLD_LISTENER_REPORT);
 2015                                 if (error == 0) {
 2016                                         inm->in6m_timer = odelay;
 2017                                         V_current_state_timers_running6 = 1;
 2018                                 }
 2019                         }
 2020                         break;
 2021 
 2022                 case MLD_VERSION_2:
 2023                         /*
 2024                          * Defer update of T0 to T1, until the first copy
 2025                          * of the state change has been transmitted.
 2026                          */
 2027                         syncstates = 0;
 2028 
 2029                         /*
 2030                          * Immediately enqueue a State-Change Report for
 2031                          * this interface, freeing any previous reports.
 2032                          * Don't kick the timers if there is nothing to do,
 2033                          * or if an error occurred.
 2034                          */
 2035                         mq = &inm->in6m_scq;
 2036                         mbufq_drain(mq);
 2037                         retval = mld_v2_enqueue_group_record(mq, inm, 1,
 2038                             0, 0, (mli->mli_flags & MLIF_USEALLOW));
 2039                         CTR2(KTR_MLD, "%s: enqueue record = %d",
 2040                             __func__, retval);
 2041                         if (retval <= 0) {
 2042                                 error = retval * -1;
 2043                                 break;
 2044                         }
 2045 
 2046                         /*
 2047                          * Schedule transmission of pending state-change
 2048                          * report up to RV times for this link. The timer
 2049                          * will fire at the next mld_fasttimo (~200ms),
 2050                          * giving us an opportunity to merge the reports.
 2051                          *
 2052                          * If a delay was provided to this function, only
 2053                          * use this delay if sooner than the existing one.
 2054                          */
 2055                         KASSERT(mli->mli_rv > 1,
 2056                            ("%s: invalid robustness %d", __func__,
 2057                             mli->mli_rv));
 2058                         inm->in6m_scrv = mli->mli_rv;
 2059                         if (delay) {
 2060                                 if (inm->in6m_sctimer > 1) {
 2061                                         inm->in6m_sctimer =
 2062                                             min(inm->in6m_sctimer, delay);
 2063                                 } else
 2064                                         inm->in6m_sctimer = delay;
 2065                         } else
 2066                                 inm->in6m_sctimer = 1;
 2067                         V_state_change_timers_running6 = 1;
 2068 
 2069                         error = 0;
 2070                         break;
 2071                 }
 2072         }
 2073 
 2074         /*
 2075          * Only update the T0 state if state change is atomic,
 2076          * i.e. we don't need to wait for a timer to fire before we
 2077          * can consider the state change to have been communicated.
 2078          */
 2079         if (syncstates) {
 2080                 in6m_commit(inm);
 2081                 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
 2082                     ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2083                     if_name(inm->in6m_ifp));
 2084         }
 2085 
 2086         return (error);
 2087 }
 2088 
 2089 /*
 2090  * Issue an intermediate state change during the life-cycle.
 2091  */
 2092 static int
 2093 mld_handle_state_change(struct in6_multi *inm, struct mld_ifsoftc *mli)
 2094 {
 2095         struct ifnet            *ifp;
 2096         int                      retval;
 2097 #ifdef KTR
 2098         char                     ip6tbuf[INET6_ADDRSTRLEN];
 2099 #endif
 2100 
 2101         CTR4(KTR_MLD, "%s: state change for %s on ifp %p(%s)",
 2102             __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2103             inm->in6m_ifp, if_name(inm->in6m_ifp));
 2104 
 2105         ifp = inm->in6m_ifp;
 2106 
 2107         IN6_MULTI_LOCK_ASSERT();
 2108         MLD_LOCK_ASSERT();
 2109 
 2110         KASSERT(mli && mli->mli_ifp == ifp,
 2111             ("%s: inconsistent ifp", __func__));
 2112 
 2113         if ((ifp->if_flags & IFF_LOOPBACK) ||
 2114             (mli->mli_flags & MLIF_SILENT) ||
 2115             !mld_is_addr_reported(&inm->in6m_addr) ||
 2116             (mli->mli_version != MLD_VERSION_2)) {
 2117                 if (!mld_is_addr_reported(&inm->in6m_addr)) {
 2118                         CTR1(KTR_MLD,
 2119 "%s: not kicking state machine for silent group", __func__);
 2120                 }
 2121                 CTR1(KTR_MLD, "%s: nothing to do", __func__);
 2122                 in6m_commit(inm);
 2123                 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
 2124                     ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2125                     if_name(inm->in6m_ifp));
 2126                 return (0);
 2127         }
 2128 
 2129         mbufq_drain(&inm->in6m_scq);
 2130 
 2131         retval = mld_v2_enqueue_group_record(&inm->in6m_scq, inm, 1, 0, 0,
 2132             (mli->mli_flags & MLIF_USEALLOW));
 2133         CTR2(KTR_MLD, "%s: enqueue record = %d", __func__, retval);
 2134         if (retval <= 0)
 2135                 return (-retval);
 2136 
 2137         /*
 2138          * If record(s) were enqueued, start the state-change
 2139          * report timer for this group.
 2140          */
 2141         inm->in6m_scrv = mli->mli_rv;
 2142         inm->in6m_sctimer = 1;
 2143         V_state_change_timers_running6 = 1;
 2144 
 2145         return (0);
 2146 }
 2147 
 2148 /*
 2149  * Perform the final leave for a multicast address.
 2150  *
 2151  * When leaving a group:
 2152  *  MLDv1 sends a DONE message, if and only if we are the reporter.
 2153  *  MLDv2 enqueues a state-change report containing a transition
 2154  *  to INCLUDE {} for immediate transmission.
 2155  */
 2156 static void
 2157 mld_final_leave(struct in6_multi *inm, struct mld_ifsoftc *mli)
 2158 {
 2159         int syncstates;
 2160 #ifdef KTR
 2161         char ip6tbuf[INET6_ADDRSTRLEN];
 2162 #endif
 2163 
 2164         syncstates = 1;
 2165 
 2166         CTR4(KTR_MLD, "%s: final leave %s on ifp %p(%s)",
 2167             __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2168             inm->in6m_ifp, if_name(inm->in6m_ifp));
 2169 
 2170         IN6_MULTI_LOCK_ASSERT();
 2171         MLD_LOCK_ASSERT();
 2172 
 2173         switch (inm->in6m_state) {
 2174         case MLD_NOT_MEMBER:
 2175         case MLD_SILENT_MEMBER:
 2176         case MLD_LEAVING_MEMBER:
 2177                 /* Already leaving or left; do nothing. */
 2178                 CTR1(KTR_MLD,
 2179 "%s: not kicking state machine for silent group", __func__);
 2180                 break;
 2181         case MLD_REPORTING_MEMBER:
 2182         case MLD_IDLE_MEMBER:
 2183         case MLD_G_QUERY_PENDING_MEMBER:
 2184         case MLD_SG_QUERY_PENDING_MEMBER:
 2185                 if (mli->mli_version == MLD_VERSION_1) {
 2186 #ifdef INVARIANTS
 2187                         if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
 2188                             inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER)
 2189                         panic("%s: MLDv2 state reached, not MLDv2 mode",
 2190                              __func__);
 2191 #endif
 2192                         mld_v1_transmit_report(inm, MLD_LISTENER_DONE);
 2193                         inm->in6m_state = MLD_NOT_MEMBER;
 2194                         V_current_state_timers_running6 = 1;
 2195                 } else if (mli->mli_version == MLD_VERSION_2) {
 2196                         /*
 2197                          * Stop group timer and all pending reports.
 2198                          * Immediately enqueue a state-change report
 2199                          * TO_IN {} to be sent on the next fast timeout,
 2200                          * giving us an opportunity to merge reports.
 2201                          */
 2202                         mbufq_drain(&inm->in6m_scq);
 2203                         inm->in6m_timer = 0;
 2204                         inm->in6m_scrv = mli->mli_rv;
 2205                         CTR4(KTR_MLD, "%s: Leaving %s/%s with %d "
 2206                             "pending retransmissions.", __func__,
 2207                             ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2208                             if_name(inm->in6m_ifp), inm->in6m_scrv);
 2209                         if (inm->in6m_scrv == 0) {
 2210                                 inm->in6m_state = MLD_NOT_MEMBER;
 2211                                 inm->in6m_sctimer = 0;
 2212                         } else {
 2213                                 int retval;
 2214 
 2215                                 in6m_acquire_locked(inm);
 2216 
 2217                                 retval = mld_v2_enqueue_group_record(
 2218                                     &inm->in6m_scq, inm, 1, 0, 0,
 2219                                     (mli->mli_flags & MLIF_USEALLOW));
 2220                                 KASSERT(retval != 0,
 2221                                     ("%s: enqueue record = %d", __func__,
 2222                                      retval));
 2223 
 2224                                 inm->in6m_state = MLD_LEAVING_MEMBER;
 2225                                 inm->in6m_sctimer = 1;
 2226                                 V_state_change_timers_running6 = 1;
 2227                                 syncstates = 0;
 2228                         }
 2229                         break;
 2230                 }
 2231                 break;
 2232         case MLD_LAZY_MEMBER:
 2233         case MLD_SLEEPING_MEMBER:
 2234         case MLD_AWAKENING_MEMBER:
 2235                 /* Our reports are suppressed; do nothing. */
 2236                 break;
 2237         }
 2238 
 2239         if (syncstates) {
 2240                 in6m_commit(inm);
 2241                 CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
 2242                     ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2243                     if_name(inm->in6m_ifp));
 2244                 inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
 2245                 CTR3(KTR_MLD, "%s: T1 now MCAST_UNDEFINED for %p/%s",
 2246                     __func__, &inm->in6m_addr, if_name(inm->in6m_ifp));
 2247         }
 2248 }
 2249 
 2250 /*
 2251  * Enqueue an MLDv2 group record to the given output queue.
 2252  *
 2253  * If is_state_change is zero, a current-state record is appended.
 2254  * If is_state_change is non-zero, a state-change report is appended.
 2255  *
 2256  * If is_group_query is non-zero, an mbuf packet chain is allocated.
 2257  * If is_group_query is zero, and if there is a packet with free space
 2258  * at the tail of the queue, it will be appended to providing there
 2259  * is enough free space.
 2260  * Otherwise a new mbuf packet chain is allocated.
 2261  *
 2262  * If is_source_query is non-zero, each source is checked to see if
 2263  * it was recorded for a Group-Source query, and will be omitted if
 2264  * it is not both in-mode and recorded.
 2265  *
 2266  * If use_block_allow is non-zero, state change reports for initial join
 2267  * and final leave, on an inclusive mode group with a source list, will be
 2268  * rewritten to use the ALLOW_NEW and BLOCK_OLD record types, respectively.
 2269  *
 2270  * The function will attempt to allocate leading space in the packet
 2271  * for the IPv6+ICMP headers to be prepended without fragmenting the chain.
 2272  *
 2273  * If successful the size of all data appended to the queue is returned,
 2274  * otherwise an error code less than zero is returned, or zero if
 2275  * no record(s) were appended.
 2276  */
 2277 static int
 2278 mld_v2_enqueue_group_record(struct mbufq *mq, struct in6_multi *inm,
 2279     const int is_state_change, const int is_group_query,
 2280     const int is_source_query, const int use_block_allow)
 2281 {
 2282         struct mldv2_record      mr;
 2283         struct mldv2_record     *pmr;
 2284         struct ifnet            *ifp;
 2285         struct ip6_msource      *ims, *nims;
 2286         struct mbuf             *m0, *m, *md;
 2287         int                      error, is_filter_list_change;
 2288         int                      minrec0len, m0srcs, msrcs, nbytes, off;
 2289         int                      record_has_sources;
 2290         int                      now;
 2291         int                      type;
 2292         uint8_t                  mode;
 2293 #ifdef KTR
 2294         char                     ip6tbuf[INET6_ADDRSTRLEN];
 2295 #endif
 2296 
 2297         IN6_MULTI_LOCK_ASSERT();
 2298 
 2299         error = 0;
 2300         ifp = inm->in6m_ifp;
 2301         is_filter_list_change = 0;
 2302         m = NULL;
 2303         m0 = NULL;
 2304         m0srcs = 0;
 2305         msrcs = 0;
 2306         nbytes = 0;
 2307         nims = NULL;
 2308         record_has_sources = 1;
 2309         pmr = NULL;
 2310         type = MLD_DO_NOTHING;
 2311         mode = inm->in6m_st[1].iss_fmode;
 2312 
 2313         /*
 2314          * If we did not transition out of ASM mode during t0->t1,
 2315          * and there are no source nodes to process, we can skip
 2316          * the generation of source records.
 2317          */
 2318         if (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0 &&
 2319             inm->in6m_nsrc == 0)
 2320                 record_has_sources = 0;
 2321 
 2322         if (is_state_change) {
 2323                 /*
 2324                  * Queue a state change record.
 2325                  * If the mode did not change, and there are non-ASM
 2326                  * listeners or source filters present,
 2327                  * we potentially need to issue two records for the group.
 2328                  * If there are ASM listeners, and there was no filter
 2329                  * mode transition of any kind, do nothing.
 2330                  *
 2331                  * If we are transitioning to MCAST_UNDEFINED, we need
 2332                  * not send any sources. A transition to/from this state is
 2333                  * considered inclusive with some special treatment.
 2334                  *
 2335                  * If we are rewriting initial joins/leaves to use
 2336                  * ALLOW/BLOCK, and the group's membership is inclusive,
 2337                  * we need to send sources in all cases.
 2338                  */
 2339                 if (mode != inm->in6m_st[0].iss_fmode) {
 2340                         if (mode == MCAST_EXCLUDE) {
 2341                                 CTR1(KTR_MLD, "%s: change to EXCLUDE",
 2342                                     __func__);
 2343                                 type = MLD_CHANGE_TO_EXCLUDE_MODE;
 2344                         } else {
 2345                                 CTR1(KTR_MLD, "%s: change to INCLUDE",
 2346                                     __func__);
 2347                                 if (use_block_allow) {
 2348                                         /*
 2349                                          * XXX
 2350                                          * Here we're interested in state
 2351                                          * edges either direction between
 2352                                          * MCAST_UNDEFINED and MCAST_INCLUDE.
 2353                                          * Perhaps we should just check
 2354                                          * the group state, rather than
 2355                                          * the filter mode.
 2356                                          */
 2357                                         if (mode == MCAST_UNDEFINED) {
 2358                                                 type = MLD_BLOCK_OLD_SOURCES;
 2359                                         } else {
 2360                                                 type = MLD_ALLOW_NEW_SOURCES;
 2361                                         }
 2362                                 } else {
 2363                                         type = MLD_CHANGE_TO_INCLUDE_MODE;
 2364                                         if (mode == MCAST_UNDEFINED)
 2365                                                 record_has_sources = 0;
 2366                                 }
 2367                         }
 2368                 } else {
 2369                         if (record_has_sources) {
 2370                                 is_filter_list_change = 1;
 2371                         } else {
 2372                                 type = MLD_DO_NOTHING;
 2373                         }
 2374                 }
 2375         } else {
 2376                 /*
 2377                  * Queue a current state record.
 2378                  */
 2379                 if (mode == MCAST_EXCLUDE) {
 2380                         type = MLD_MODE_IS_EXCLUDE;
 2381                 } else if (mode == MCAST_INCLUDE) {
 2382                         type = MLD_MODE_IS_INCLUDE;
 2383                         KASSERT(inm->in6m_st[1].iss_asm == 0,
 2384                             ("%s: inm %p is INCLUDE but ASM count is %d",
 2385                              __func__, inm, inm->in6m_st[1].iss_asm));
 2386                 }
 2387         }
 2388 
 2389         /*
 2390          * Generate the filter list changes using a separate function.
 2391          */
 2392         if (is_filter_list_change)
 2393                 return (mld_v2_enqueue_filter_change(mq, inm));
 2394 
 2395         if (type == MLD_DO_NOTHING) {
 2396                 CTR3(KTR_MLD, "%s: nothing to do for %s/%s",
 2397                     __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2398                     if_name(inm->in6m_ifp));
 2399                 return (0);
 2400         }
 2401 
 2402         /*
 2403          * If any sources are present, we must be able to fit at least
 2404          * one in the trailing space of the tail packet's mbuf,
 2405          * ideally more.
 2406          */
 2407         minrec0len = sizeof(struct mldv2_record);
 2408         if (record_has_sources)
 2409                 minrec0len += sizeof(struct in6_addr);
 2410 
 2411         CTR4(KTR_MLD, "%s: queueing %s for %s/%s", __func__,
 2412             mld_rec_type_to_str(type),
 2413             ip6_sprintf(ip6tbuf, &inm->in6m_addr),
 2414             if_name(inm->in6m_ifp));
 2415 
 2416         /*
 2417          * Check if we have a packet in the tail of the queue for this
 2418          * group into which the first group record for this group will fit.
 2419          * Otherwise allocate a new packet.
 2420          * Always allocate leading space for IP6+RA+ICMPV6+REPORT.
 2421          * Note: Group records for G/GSR query responses MUST be sent
 2422          * in their own packet.
 2423          */
 2424         m0 = mbufq_last(mq);
 2425         if (!is_group_query &&
 2426             m0 != NULL &&
 2427             (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <= MLD_V2_REPORT_MAXRECS) &&
 2428             (m0->m_pkthdr.len + minrec0len) <
 2429              (ifp->if_mtu - MLD_MTUSPACE)) {
 2430                 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
 2431                             sizeof(struct mldv2_record)) /
 2432                             sizeof(struct in6_addr);
 2433                 m = m0;
 2434                 CTR1(KTR_MLD, "%s: use existing packet", __func__);
 2435         } else {
 2436                 if (mbufq_full(mq)) {
 2437                         CTR1(KTR_MLD, "%s: outbound queue full", __func__);
 2438                         return (-ENOMEM);
 2439                 }
 2440                 m = NULL;
 2441                 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
 2442                     sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
 2443                 if (!is_state_change && !is_group_query)
 2444                         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
 2445                 if (m == NULL)
 2446                         m = m_gethdr(M_NOWAIT, MT_DATA);
 2447                 if (m == NULL)
 2448                         return (-ENOMEM);
 2449 
 2450                 mld_save_context(m, ifp);
 2451 
 2452                 CTR1(KTR_MLD, "%s: allocated first packet", __func__);
 2453         }
 2454 
 2455         /*
 2456          * Append group record.
 2457          * If we have sources, we don't know how many yet.
 2458          */
 2459         mr.mr_type = type;
 2460         mr.mr_datalen = 0;
 2461         mr.mr_numsrc = 0;
 2462         mr.mr_addr = inm->in6m_addr;
 2463         in6_clearscope(&mr.mr_addr);
 2464         if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
 2465                 if (m != m0)
 2466                         m_freem(m);
 2467                 CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
 2468                 return (-ENOMEM);
 2469         }
 2470         nbytes += sizeof(struct mldv2_record);
 2471 
 2472         /*
 2473          * Append as many sources as will fit in the first packet.
 2474          * If we are appending to a new packet, the chain allocation
 2475          * may potentially use clusters; use m_getptr() in this case.
 2476          * If we are appending to an existing packet, we need to obtain
 2477          * a pointer to the group record after m_append(), in case a new
 2478          * mbuf was allocated.
 2479          *
 2480          * Only append sources which are in-mode at t1. If we are
 2481          * transitioning to MCAST_UNDEFINED state on the group, and
 2482          * use_block_allow is zero, do not include source entries.
 2483          * Otherwise, we need to include this source in the report.
 2484          *
 2485          * Only report recorded sources in our filter set when responding
 2486          * to a group-source query.
 2487          */
 2488         if (record_has_sources) {
 2489                 if (m == m0) {
 2490                         md = m_last(m);
 2491                         pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
 2492                             md->m_len - nbytes);
 2493                 } else {
 2494                         md = m_getptr(m, 0, &off);
 2495                         pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
 2496                             off);
 2497                 }
 2498                 msrcs = 0;
 2499                 RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs,
 2500                     nims) {
 2501                         CTR2(KTR_MLD, "%s: visit node %s", __func__,
 2502                             ip6_sprintf(ip6tbuf, &ims->im6s_addr));
 2503                         now = im6s_get_mode(inm, ims, 1);
 2504                         CTR2(KTR_MLD, "%s: node is %d", __func__, now);
 2505                         if ((now != mode) ||
 2506                             (now == mode &&
 2507                              (!use_block_allow && mode == MCAST_UNDEFINED))) {
 2508                                 CTR1(KTR_MLD, "%s: skip node", __func__);
 2509                                 continue;
 2510                         }
 2511                         if (is_source_query && ims->im6s_stp == 0) {
 2512                                 CTR1(KTR_MLD, "%s: skip unrecorded node",
 2513                                     __func__);
 2514                                 continue;
 2515                         }
 2516                         CTR1(KTR_MLD, "%s: append node", __func__);
 2517                         if (!m_append(m, sizeof(struct in6_addr),
 2518                             (void *)&ims->im6s_addr)) {
 2519                                 if (m != m0)
 2520                                         m_freem(m);
 2521                                 CTR1(KTR_MLD, "%s: m_append() failed.",
 2522                                     __func__);
 2523                                 return (-ENOMEM);
 2524                         }
 2525                         nbytes += sizeof(struct in6_addr);
 2526                         ++msrcs;
 2527                         if (msrcs == m0srcs)
 2528                                 break;
 2529                 }
 2530                 CTR2(KTR_MLD, "%s: msrcs is %d this packet", __func__,
 2531                     msrcs);
 2532                 pmr->mr_numsrc = htons(msrcs);
 2533                 nbytes += (msrcs * sizeof(struct in6_addr));
 2534         }
 2535 
 2536         if (is_source_query && msrcs == 0) {
 2537                 CTR1(KTR_MLD, "%s: no recorded sources to report", __func__);
 2538                 if (m != m0)
 2539                         m_freem(m);
 2540                 return (0);
 2541         }
 2542 
 2543         /*
 2544          * We are good to go with first packet.
 2545          */
 2546         if (m != m0) {
 2547                 CTR1(KTR_MLD, "%s: enqueueing first packet", __func__);
 2548                 m->m_pkthdr.PH_vt.vt_nrecs = 1;
 2549                 mbufq_enqueue(mq, m);
 2550         } else
 2551                 m->m_pkthdr.PH_vt.vt_nrecs++;
 2552 
 2553         /*
 2554          * No further work needed if no source list in packet(s).
 2555          */
 2556         if (!record_has_sources)
 2557                 return (nbytes);
 2558 
 2559         /*
 2560          * Whilst sources remain to be announced, we need to allocate
 2561          * a new packet and fill out as many sources as will fit.
 2562          * Always try for a cluster first.
 2563          */
 2564         while (nims != NULL) {
 2565                 if (mbufq_full(mq)) {
 2566                         CTR1(KTR_MLD, "%s: outbound queue full", __func__);
 2567                         return (-ENOMEM);
 2568                 }
 2569                 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
 2570                 if (m == NULL)
 2571                         m = m_gethdr(M_NOWAIT, MT_DATA);
 2572                 if (m == NULL)
 2573                         return (-ENOMEM);
 2574                 mld_save_context(m, ifp);
 2575                 md = m_getptr(m, 0, &off);
 2576                 pmr = (struct mldv2_record *)(mtod(md, uint8_t *) + off);
 2577                 CTR1(KTR_MLD, "%s: allocated next packet", __func__);
 2578 
 2579                 if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
 2580                         if (m != m0)
 2581                                 m_freem(m);
 2582                         CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
 2583                         return (-ENOMEM);
 2584                 }
 2585                 m->m_pkthdr.PH_vt.vt_nrecs = 1;
 2586                 nbytes += sizeof(struct mldv2_record);
 2587 
 2588                 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
 2589                     sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
 2590 
 2591                 msrcs = 0;
 2592                 RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
 2593                         CTR2(KTR_MLD, "%s: visit node %s",
 2594                             __func__, ip6_sprintf(ip6tbuf, &ims->im6s_addr));
 2595                         now = im6s_get_mode(inm, ims, 1);
 2596                         if ((now != mode) ||
 2597                             (now == mode &&
 2598                              (!use_block_allow && mode == MCAST_UNDEFINED))) {
 2599                                 CTR1(KTR_MLD, "%s: skip node", __func__);
 2600                                 continue;
 2601                         }
 2602                         if (is_source_query && ims->im6s_stp == 0) {
 2603                                 CTR1(KTR_MLD, "%s: skip unrecorded node",
 2604                                     __func__);
 2605                                 continue;
 2606                         }
 2607                         CTR1(KTR_MLD, "%s: append node", __func__);
 2608                         if (!m_append(m, sizeof(struct in6_addr),
 2609                             (void *)&ims->im6s_addr)) {
 2610                                 if (m != m0)
 2611                                         m_freem(m);
 2612                                 CTR1(KTR_MLD, "%s: m_append() failed.",
 2613                                     __func__);
 2614                                 return (-ENOMEM);
 2615                         }
 2616                         ++msrcs;
 2617                         if (msrcs == m0srcs)
 2618                                 break;
 2619                 }
 2620                 pmr->mr_numsrc = htons(msrcs);
 2621                 nbytes += (msrcs * sizeof(struct in6_addr));
 2622 
 2623                 CTR1(KTR_MLD, "%s: enqueueing next packet", __func__);
 2624                 mbufq_enqueue(mq, m);
 2625         }
 2626 
 2627         return (nbytes);
 2628 }
 2629 
 2630 /*
 2631  * Type used to mark record pass completion.
 2632  * We exploit the fact we can cast to this easily from the
 2633  * current filter modes on each ip_msource node.
 2634  */
 2635 typedef enum {
 2636         REC_NONE = 0x00,        /* MCAST_UNDEFINED */
 2637         REC_ALLOW = 0x01,       /* MCAST_INCLUDE */
 2638         REC_BLOCK = 0x02,       /* MCAST_EXCLUDE */
 2639         REC_FULL = REC_ALLOW | REC_BLOCK
 2640 } rectype_t;
 2641 
 2642 /*
 2643  * Enqueue an MLDv2 filter list change to the given output queue.
 2644  *
 2645  * Source list filter state is held in an RB-tree. When the filter list
 2646  * for a group is changed without changing its mode, we need to compute
 2647  * the deltas between T0 and T1 for each source in the filter set,
 2648  * and enqueue the appropriate ALLOW_NEW/BLOCK_OLD records.
 2649  *
 2650  * As we may potentially queue two record types, and the entire R-B tree
 2651  * needs to be walked at once, we break this out into its own function
 2652  * so we can generate a tightly packed queue of packets.
 2653  *
 2654  * XXX This could be written to only use one tree walk, although that makes
 2655  * serializing into the mbuf chains a bit harder. For now we do two walks
 2656  * which makes things easier on us, and it may or may not be harder on
 2657  * the L2 cache.
 2658  *
 2659  * If successful the size of all data appended to the queue is returned,
 2660  * otherwise an error code less than zero is returned, or zero if
 2661  * no record(s) were appended.
 2662  */
 2663 static int
 2664 mld_v2_enqueue_filter_change(struct mbufq *mq, struct in6_multi *inm)
 2665 {
 2666         static const int MINRECLEN =
 2667             sizeof(struct mldv2_record) + sizeof(struct in6_addr);
 2668         struct ifnet            *ifp;
 2669         struct mldv2_record      mr;
 2670         struct mldv2_record     *pmr;
 2671         struct ip6_msource      *ims, *nims;
 2672         struct mbuf             *m, *m0, *md;
 2673         int                      m0srcs, nbytes, npbytes, off, rsrcs, schanged;
 2674         int                      nallow, nblock;
 2675         uint8_t                  mode, now, then;
 2676         rectype_t                crt, drt, nrt;
 2677 #ifdef KTR
 2678         char                     ip6tbuf[INET6_ADDRSTRLEN];
 2679 #endif
 2680 
 2681         IN6_MULTI_LOCK_ASSERT();
 2682 
 2683         if (inm->in6m_nsrc == 0 ||
 2684             (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0))
 2685                 return (0);
 2686 
 2687         ifp = inm->in6m_ifp;                    /* interface */
 2688         mode = inm->in6m_st[1].iss_fmode;       /* filter mode at t1 */
 2689         crt = REC_NONE; /* current group record type */
 2690         drt = REC_NONE; /* mask of completed group record types */
 2691         nrt = REC_NONE; /* record type for current node */
 2692         m0srcs = 0;     /* # source which will fit in current mbuf chain */
 2693         npbytes = 0;    /* # of bytes appended this packet */
 2694         nbytes = 0;     /* # of bytes appended to group's state-change queue */
 2695         rsrcs = 0;      /* # sources encoded in current record */
 2696         schanged = 0;   /* # nodes encoded in overall filter change */
 2697         nallow = 0;     /* # of source entries in ALLOW_NEW */
 2698         nblock = 0;     /* # of source entries in BLOCK_OLD */
 2699         nims = NULL;    /* next tree node pointer */
 2700 
 2701         /*
 2702          * For each possible filter record mode.
 2703          * The first kind of source we encounter tells us which
 2704          * is the first kind of record we start appending.
 2705          * If a node transitioned to UNDEFINED at t1, its mode is treated
 2706          * as the inverse of the group's filter mode.
 2707          */
 2708         while (drt != REC_FULL) {
 2709                 do {
 2710                         m0 = mbufq_last(mq);
 2711                         if (m0 != NULL &&
 2712                             (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <=
 2713                              MLD_V2_REPORT_MAXRECS) &&
 2714                             (m0->m_pkthdr.len + MINRECLEN) <
 2715                              (ifp->if_mtu - MLD_MTUSPACE)) {
 2716                                 m = m0;
 2717                                 m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
 2718                                             sizeof(struct mldv2_record)) /
 2719                                             sizeof(struct in6_addr);
 2720                                 CTR1(KTR_MLD,
 2721                                     "%s: use previous packet", __func__);
 2722                         } else {
 2723                                 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
 2724                                 if (m == NULL)
 2725                                         m = m_gethdr(M_NOWAIT, MT_DATA);
 2726                                 if (m == NULL) {
 2727                                         CTR1(KTR_MLD,
 2728                                             "%s: m_get*() failed", __func__);
 2729                                         return (-ENOMEM);
 2730                                 }
 2731                                 m->m_pkthdr.PH_vt.vt_nrecs = 0;
 2732                                 mld_save_context(m, ifp);
 2733                                 m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
 2734                                     sizeof(struct mldv2_record)) /
 2735                                     sizeof(struct in6_addr);
 2736                                 npbytes = 0;
 2737                                 CTR1(KTR_MLD,
 2738                                     "%s: allocated new packet", __func__);
 2739                         }
 2740                         /*
 2741                          * Append the MLD group record header to the
 2742                          * current packet's data area.
 2743                          * Recalculate pointer to free space for next
 2744                          * group record, in case m_append() allocated
 2745                          * a new mbuf or cluster.
 2746                          */
 2747                         memset(&mr, 0, sizeof(mr));
 2748                         mr.mr_addr = inm->in6m_addr;
 2749                         in6_clearscope(&mr.mr_addr);
 2750                         if (!m_append(m, sizeof(mr), (void *)&mr)) {
 2751                                 if (m != m0)
 2752                                         m_freem(m);
 2753                                 CTR1(KTR_MLD,
 2754                                     "%s: m_append() failed", __func__);
 2755                                 return (-ENOMEM);
 2756                         }
 2757                         npbytes += sizeof(struct mldv2_record);
 2758                         if (m != m0) {
 2759                                 /* new packet; offset in chain */
 2760                                 md = m_getptr(m, npbytes -
 2761                                     sizeof(struct mldv2_record), &off);
 2762                                 pmr = (struct mldv2_record *)(mtod(md,
 2763                                     uint8_t *) + off);
 2764                         } else {
 2765                                 /* current packet; offset from last append */
 2766                                 md = m_last(m);
 2767                                 pmr = (struct mldv2_record *)(mtod(md,
 2768                                     uint8_t *) + md->m_len -
 2769                                     sizeof(struct mldv2_record));
 2770                         }
 2771                         /*
 2772                          * Begin walking the tree for this record type
 2773                          * pass, or continue from where we left off
 2774                          * previously if we had to allocate a new packet.
 2775                          * Only report deltas in-mode at t1.
 2776                          * We need not report included sources as allowed
 2777                          * if we are in inclusive mode on the group,
 2778                          * however the converse is not true.
 2779                          */
 2780                         rsrcs = 0;
 2781                         if (nims == NULL) {
 2782                                 nims = RB_MIN(ip6_msource_tree,
 2783                                     &inm->in6m_srcs);
 2784                         }
 2785                         RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
 2786                                 CTR2(KTR_MLD, "%s: visit node %s", __func__,
 2787                                     ip6_sprintf(ip6tbuf, &ims->im6s_addr));
 2788                                 now = im6s_get_mode(inm, ims, 1);
 2789                                 then = im6s_get_mode(inm, ims, 0);
 2790                                 CTR3(KTR_MLD, "%s: mode: t0 %d, t1 %d",
 2791                                     __func__, then, now);
 2792                                 if (now == then) {
 2793                                         CTR1(KTR_MLD,
 2794                                             "%s: skip unchanged", __func__);
 2795                                         continue;
 2796                                 }
 2797                                 if (mode == MCAST_EXCLUDE &&
 2798                                     now == MCAST_INCLUDE) {
 2799                                         CTR1(KTR_MLD,
 2800                                             "%s: skip IN src on EX group",
 2801                                             __func__);
 2802                                         continue;
 2803                                 }
 2804                                 nrt = (rectype_t)now;
 2805                                 if (nrt == REC_NONE)
 2806                                         nrt = (rectype_t)(~mode & REC_FULL);
 2807                                 if (schanged++ == 0) {
 2808                                         crt = nrt;
 2809                                 } else if (crt != nrt)
 2810                                         continue;
 2811                                 if (!m_append(m, sizeof(struct in6_addr),
 2812                                     (void *)&ims->im6s_addr)) {
 2813                                         if (m != m0)
 2814                                                 m_freem(m);
 2815                                         CTR1(KTR_MLD,
 2816                                             "%s: m_append() failed", __func__);
 2817                                         return (-ENOMEM);
 2818                                 }
 2819                                 nallow += !!(crt == REC_ALLOW);
 2820                                 nblock += !!(crt == REC_BLOCK);
 2821                                 if (++rsrcs == m0srcs)
 2822                                         break;
 2823                         }
 2824                         /*
 2825                          * If we did not append any tree nodes on this
 2826                          * pass, back out of allocations.
 2827                          */
 2828                         if (rsrcs == 0) {
 2829                                 npbytes -= sizeof(struct mldv2_record);
 2830                                 if (m != m0) {
 2831                                         CTR1(KTR_MLD,
 2832                                             "%s: m_free(m)", __func__);
 2833                                         m_freem(m);
 2834                                 } else {
 2835                                         CTR1(KTR_MLD,
 2836                                             "%s: m_adj(m, -mr)", __func__);
 2837                                         m_adj(m, -((int)sizeof(
 2838                                             struct mldv2_record)));
 2839                                 }
 2840                                 continue;
 2841                         }
 2842                         npbytes += (rsrcs * sizeof(struct in6_addr));
 2843                         if (crt == REC_ALLOW)
 2844                                 pmr->mr_type = MLD_ALLOW_NEW_SOURCES;
 2845                         else if (crt == REC_BLOCK)
 2846                                 pmr->mr_type = MLD_BLOCK_OLD_SOURCES;
 2847                         pmr->mr_numsrc = htons(rsrcs);
 2848                         /*
 2849                          * Count the new group record, and enqueue this
 2850                          * packet if it wasn't already queued.
 2851                          */
 2852                         m->m_pkthdr.PH_vt.vt_nrecs++;
 2853                         if (m != m0)
 2854                                 mbufq_enqueue(mq, m);
 2855                         nbytes += npbytes;
 2856                 } while (nims != NULL);
 2857                 drt |= crt;
 2858                 crt = (~crt & REC_FULL);
 2859         }
 2860 
 2861         CTR3(KTR_MLD, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
 2862             nallow, nblock);
 2863 
 2864         return (nbytes);
 2865 }
 2866 
 2867 static int
 2868 mld_v2_merge_state_changes(struct in6_multi *inm, struct mbufq *scq)
 2869 {
 2870         struct mbufq    *gq;
 2871         struct mbuf     *m;             /* pending state-change */
 2872         struct mbuf     *m0;            /* copy of pending state-change */
 2873         struct mbuf     *mt;            /* last state-change in packet */
 2874         int              docopy, domerge;
 2875         u_int            recslen;
 2876 
 2877         docopy = 0;
 2878         domerge = 0;
 2879         recslen = 0;
 2880 
 2881         IN6_MULTI_LOCK_ASSERT();
 2882         MLD_LOCK_ASSERT();
 2883 
 2884         /*
 2885          * If there are further pending retransmissions, make a writable
 2886          * copy of each queued state-change message before merging.
 2887          */
 2888         if (inm->in6m_scrv > 0)
 2889                 docopy = 1;
 2890 
 2891         gq = &inm->in6m_scq;
 2892 #ifdef KTR
 2893         if (mbufq_first(gq) == NULL) {
 2894                 CTR2(KTR_MLD, "%s: WARNING: queue for inm %p is empty",
 2895                     __func__, inm);
 2896         }
 2897 #endif
 2898 
 2899         m = mbufq_first(gq);
 2900         while (m != NULL) {
 2901                 /*
 2902                  * Only merge the report into the current packet if
 2903                  * there is sufficient space to do so; an MLDv2 report
 2904                  * packet may only contain 65,535 group records.
 2905                  * Always use a simple mbuf chain concatentation to do this,
 2906                  * as large state changes for single groups may have
 2907                  * allocated clusters.
 2908                  */
 2909                 domerge = 0;
 2910                 mt = mbufq_last(scq);
 2911                 if (mt != NULL) {
 2912                         recslen = m_length(m, NULL);
 2913 
 2914                         if ((mt->m_pkthdr.PH_vt.vt_nrecs +
 2915                             m->m_pkthdr.PH_vt.vt_nrecs <=
 2916                             MLD_V2_REPORT_MAXRECS) &&
 2917                             (mt->m_pkthdr.len + recslen <=
 2918                             (inm->in6m_ifp->if_mtu - MLD_MTUSPACE)))
 2919                                 domerge = 1;
 2920                 }
 2921 
 2922                 if (!domerge && mbufq_full(gq)) {
 2923                         CTR2(KTR_MLD,
 2924                             "%s: outbound queue full, skipping whole packet %p",
 2925                             __func__, m);
 2926                         mt = m->m_nextpkt;
 2927                         if (!docopy)
 2928                                 m_freem(m);
 2929                         m = mt;
 2930                         continue;
 2931                 }
 2932 
 2933                 if (!docopy) {
 2934                         CTR2(KTR_MLD, "%s: dequeueing %p", __func__, m);
 2935                         m0 = mbufq_dequeue(gq);
 2936                         m = m0->m_nextpkt;
 2937                 } else {
 2938                         CTR2(KTR_MLD, "%s: copying %p", __func__, m);
 2939                         m0 = m_dup(m, M_NOWAIT);
 2940                         if (m0 == NULL)
 2941                                 return (ENOMEM);
 2942                         m0->m_nextpkt = NULL;
 2943                         m = m->m_nextpkt;
 2944                 }
 2945 
 2946                 if (!domerge) {
 2947                         CTR3(KTR_MLD, "%s: queueing %p to scq %p)",
 2948                             __func__, m0, scq);
 2949                         mbufq_enqueue(scq, m0);
 2950                 } else {
 2951                         struct mbuf *mtl;       /* last mbuf of packet mt */
 2952 
 2953                         CTR3(KTR_MLD, "%s: merging %p with ifscq tail %p)",
 2954                             __func__, m0, mt);
 2955 
 2956                         mtl = m_last(mt);
 2957                         m0->m_flags &= ~M_PKTHDR;
 2958                         mt->m_pkthdr.len += recslen;
 2959                         mt->m_pkthdr.PH_vt.vt_nrecs +=
 2960                             m0->m_pkthdr.PH_vt.vt_nrecs;
 2961 
 2962                         mtl->m_next = m0;
 2963                 }
 2964         }
 2965 
 2966         return (0);
 2967 }
 2968 
 2969 /*
 2970  * Respond to a pending MLDv2 General Query.
 2971  */
 2972 static void
 2973 mld_v2_dispatch_general_query(struct mld_ifsoftc *mli)
 2974 {
 2975         struct ifmultiaddr      *ifma;
 2976         struct ifnet            *ifp;
 2977         struct in6_multi        *inm;
 2978         int                      retval;
 2979 
 2980         IN6_MULTI_LOCK_ASSERT();
 2981         MLD_LOCK_ASSERT();
 2982 
 2983         KASSERT(mli->mli_version == MLD_VERSION_2,
 2984             ("%s: called when version %d", __func__, mli->mli_version));
 2985 
 2986         /*
 2987          * Check that there are some packets queued. If so, send them first.
 2988          * For large number of groups the reply to general query can take
 2989          * many packets, we should finish sending them before starting of
 2990          * queuing the new reply.
 2991          */
 2992         if (mbufq_len(&mli->mli_gq) != 0)
 2993                 goto send;
 2994 
 2995         ifp = mli->mli_ifp;
 2996 
 2997         IF_ADDR_RLOCK(ifp);
 2998         TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
 2999                 if (ifma->ifma_addr->sa_family != AF_INET6 ||
 3000                     ifma->ifma_protospec == NULL)
 3001                         continue;
 3002 
 3003                 inm = (struct in6_multi *)ifma->ifma_protospec;
 3004                 KASSERT(ifp == inm->in6m_ifp,
 3005                     ("%s: inconsistent ifp", __func__));
 3006 
 3007                 switch (inm->in6m_state) {
 3008                 case MLD_NOT_MEMBER:
 3009                 case MLD_SILENT_MEMBER:
 3010                         break;
 3011                 case MLD_REPORTING_MEMBER:
 3012                 case MLD_IDLE_MEMBER:
 3013                 case MLD_LAZY_MEMBER:
 3014                 case MLD_SLEEPING_MEMBER:
 3015                 case MLD_AWAKENING_MEMBER:
 3016                         inm->in6m_state = MLD_REPORTING_MEMBER;
 3017                         retval = mld_v2_enqueue_group_record(&mli->mli_gq,
 3018                             inm, 0, 0, 0, 0);
 3019                         CTR2(KTR_MLD, "%s: enqueue record = %d",
 3020                             __func__, retval);
 3021                         break;
 3022                 case MLD_G_QUERY_PENDING_MEMBER:
 3023                 case MLD_SG_QUERY_PENDING_MEMBER:
 3024                 case MLD_LEAVING_MEMBER:
 3025                         break;
 3026                 }
 3027         }
 3028         IF_ADDR_RUNLOCK(ifp);
 3029 
 3030 send:
 3031         mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST);
 3032 
 3033         /*
 3034          * Slew transmission of bursts over 500ms intervals.
 3035          */
 3036         if (mbufq_first(&mli->mli_gq) != NULL) {
 3037                 mli->mli_v2_timer = 1 + MLD_RANDOM_DELAY(
 3038                     MLD_RESPONSE_BURST_INTERVAL);
 3039                 V_interface_timers_running6 = 1;
 3040         }
 3041 }
 3042 
 3043 /*
 3044  * Transmit the next pending message in the output queue.
 3045  *
 3046  * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
 3047  * MRT: Nothing needs to be done, as MLD traffic is always local to
 3048  * a link and uses a link-scope multicast address.
 3049  */
 3050 static void
 3051 mld_dispatch_packet(struct mbuf *m)
 3052 {
 3053         struct ip6_moptions      im6o;
 3054         struct ifnet            *ifp;
 3055         struct ifnet            *oifp;
 3056         struct mbuf             *m0;
 3057         struct mbuf             *md;
 3058         struct ip6_hdr          *ip6;
 3059         struct mld_hdr          *mld;
 3060         int                      error;
 3061         int                      off;
 3062         int                      type;
 3063         uint32_t                 ifindex;
 3064 
 3065         CTR2(KTR_MLD, "%s: transmit %p", __func__, m);
 3066 
 3067         /*
 3068          * Set VNET image pointer from enqueued mbuf chain
 3069          * before doing anything else. Whilst we use interface
 3070          * indexes to guard against interface detach, they are
 3071          * unique to each VIMAGE and must be retrieved.
 3072          */
 3073         ifindex = mld_restore_context(m);
 3074 
 3075         /*
 3076          * Check if the ifnet still exists. This limits the scope of
 3077          * any race in the absence of a global ifp lock for low cost
 3078          * (an array lookup).
 3079          */
 3080         ifp = ifnet_byindex(ifindex);
 3081         if (ifp == NULL) {
 3082                 CTR3(KTR_MLD, "%s: dropped %p as ifindex %u went away.",
 3083                     __func__, m, ifindex);
 3084                 m_freem(m);
 3085                 IP6STAT_INC(ip6s_noroute);
 3086                 goto out;
 3087         }
 3088 
 3089         im6o.im6o_multicast_hlim  = 1;
 3090         im6o.im6o_multicast_loop = (V_ip6_mrouter != NULL);
 3091         im6o.im6o_multicast_ifp = ifp;
 3092 
 3093         if (m->m_flags & M_MLDV1) {
 3094                 m0 = m;
 3095         } else {
 3096                 m0 = mld_v2_encap_report(ifp, m);
 3097                 if (m0 == NULL) {
 3098                         CTR2(KTR_MLD, "%s: dropped %p", __func__, m);
 3099                         IP6STAT_INC(ip6s_odropped);
 3100                         goto out;
 3101                 }
 3102         }
 3103 
 3104         mld_scrub_context(m0);
 3105         m_clrprotoflags(m);
 3106         m0->m_pkthdr.rcvif = V_loif;
 3107 
 3108         ip6 = mtod(m0, struct ip6_hdr *);
 3109 #if 0
 3110         (void)in6_setscope(&ip6->ip6_dst, ifp, NULL);   /* XXX LOR */
 3111 #else
 3112         /*
 3113          * XXX XXX Break some KPI rules to prevent an LOR which would
 3114          * occur if we called in6_setscope() at transmission.
 3115          * See comments at top of file.
 3116          */
 3117         MLD_EMBEDSCOPE(&ip6->ip6_dst, ifp->if_index);
 3118 #endif
 3119 
 3120         /*
 3121          * Retrieve the ICMPv6 type before handoff to ip6_output(),
 3122          * so we can bump the stats.
 3123          */
 3124         md = m_getptr(m0, sizeof(struct ip6_hdr), &off);
 3125         mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off);
 3126         type = mld->mld_type;
 3127 
 3128         error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o,
 3129             &oifp, NULL);
 3130         if (error) {
 3131                 CTR3(KTR_MLD, "%s: ip6_output(%p) = %d", __func__, m0, error);
 3132                 goto out;
 3133         }
 3134         ICMP6STAT_INC(icp6s_outhist[type]);
 3135         if (oifp != NULL) {
 3136                 icmp6_ifstat_inc(oifp, ifs6_out_msg);
 3137                 switch (type) {
 3138                 case MLD_LISTENER_REPORT:
 3139                 case MLDV2_LISTENER_REPORT:
 3140                         icmp6_ifstat_inc(oifp, ifs6_out_mldreport);
 3141                         break;
 3142                 case MLD_LISTENER_DONE:
 3143                         icmp6_ifstat_inc(oifp, ifs6_out_mlddone);
 3144                         break;
 3145                 }
 3146         }
 3147 out:
 3148         return;
 3149 }
 3150 
 3151 /*
 3152  * Encapsulate an MLDv2 report.
 3153  *
 3154  * KAME IPv6 requires that hop-by-hop options be passed separately,
 3155  * and that the IPv6 header be prepended in a separate mbuf.
 3156  *
 3157  * Returns a pointer to the new mbuf chain head, or NULL if the
 3158  * allocation failed.
 3159  */
 3160 static struct mbuf *
 3161 mld_v2_encap_report(struct ifnet *ifp, struct mbuf *m)
 3162 {
 3163         struct mbuf             *mh;
 3164         struct mldv2_report     *mld;
 3165         struct ip6_hdr          *ip6;
 3166         struct in6_ifaddr       *ia;
 3167         int                      mldreclen;
 3168 
 3169         KASSERT(ifp != NULL, ("%s: null ifp", __func__));
 3170         KASSERT((m->m_flags & M_PKTHDR),
 3171             ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
 3172 
 3173         /*
 3174          * RFC3590: OK to send as :: or tentative during DAD.
 3175          */
 3176         ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
 3177         if (ia == NULL)
 3178                 CTR1(KTR_MLD, "%s: warning: ia is NULL", __func__);
 3179 
 3180         mh = m_gethdr(M_NOWAIT, MT_DATA);
 3181         if (mh == NULL) {
 3182                 if (ia != NULL)
 3183                         ifa_free(&ia->ia_ifa);
 3184                 m_freem(m);
 3185                 return (NULL);
 3186         }
 3187         M_ALIGN(mh, sizeof(struct ip6_hdr) + sizeof(struct mldv2_report));
 3188 
 3189         mldreclen = m_length(m, NULL);
 3190         CTR2(KTR_MLD, "%s: mldreclen is %d", __func__, mldreclen);
 3191 
 3192         mh->m_len = sizeof(struct ip6_hdr) + sizeof(struct mldv2_report);
 3193         mh->m_pkthdr.len = sizeof(struct ip6_hdr) +
 3194             sizeof(struct mldv2_report) + mldreclen;
 3195 
 3196         ip6 = mtod(mh, struct ip6_hdr *);
 3197         ip6->ip6_flow = 0;
 3198         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 3199         ip6->ip6_vfc |= IPV6_VERSION;
 3200         ip6->ip6_nxt = IPPROTO_ICMPV6;
 3201         ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
 3202         if (ia != NULL)
 3203                 ifa_free(&ia->ia_ifa);
 3204         ip6->ip6_dst = in6addr_linklocal_allv2routers;
 3205         /* scope ID will be set in netisr */
 3206 
 3207         mld = (struct mldv2_report *)(ip6 + 1);
 3208         mld->mld_type = MLDV2_LISTENER_REPORT;
 3209         mld->mld_code = 0;
 3210         mld->mld_cksum = 0;
 3211         mld->mld_v2_reserved = 0;
 3212         mld->mld_v2_numrecs = htons(m->m_pkthdr.PH_vt.vt_nrecs);
 3213         m->m_pkthdr.PH_vt.vt_nrecs = 0;
 3214 
 3215         mh->m_next = m;
 3216         mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
 3217             sizeof(struct ip6_hdr), sizeof(struct mldv2_report) + mldreclen);
 3218         return (mh);
 3219 }
 3220 
 3221 #ifdef KTR
 3222 static char *
 3223 mld_rec_type_to_str(const int type)
 3224 {
 3225 
 3226         switch (type) {
 3227                 case MLD_CHANGE_TO_EXCLUDE_MODE:
 3228                         return "TO_EX";
 3229                         break;
 3230                 case MLD_CHANGE_TO_INCLUDE_MODE:
 3231                         return "TO_IN";
 3232                         break;
 3233                 case MLD_MODE_IS_EXCLUDE:
 3234                         return "MODE_EX";
 3235                         break;
 3236                 case MLD_MODE_IS_INCLUDE:
 3237                         return "MODE_IN";
 3238                         break;
 3239                 case MLD_ALLOW_NEW_SOURCES:
 3240                         return "ALLOW_NEW";
 3241                         break;
 3242                 case MLD_BLOCK_OLD_SOURCES:
 3243                         return "BLOCK_OLD";
 3244                         break;
 3245                 default:
 3246                         break;
 3247         }
 3248         return "unknown";
 3249 }
 3250 #endif
 3251 
 3252 static void
 3253 mld_init(void *unused __unused)
 3254 {
 3255 
 3256         CTR1(KTR_MLD, "%s: initializing", __func__);
 3257         MLD_LOCK_INIT();
 3258 
 3259         ip6_initpktopts(&mld_po);
 3260         mld_po.ip6po_hlim = 1;
 3261         mld_po.ip6po_hbh = &mld_ra.hbh;
 3262         mld_po.ip6po_prefer_tempaddr = IP6PO_TEMPADDR_NOTPREFER;
 3263         mld_po.ip6po_flags = IP6PO_DONTFRAG;
 3264 }
 3265 SYSINIT(mld_init, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_init, NULL);
 3266 
 3267 static void
 3268 mld_uninit(void *unused __unused)
 3269 {
 3270 
 3271         CTR1(KTR_MLD, "%s: tearing down", __func__);
 3272         MLD_LOCK_DESTROY();
 3273 }
 3274 SYSUNINIT(mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE, mld_uninit, NULL);
 3275 
 3276 static void
 3277 vnet_mld_init(const void *unused __unused)
 3278 {
 3279 
 3280         CTR1(KTR_MLD, "%s: initializing", __func__);
 3281 
 3282         LIST_INIT(&V_mli_head);
 3283 }
 3284 VNET_SYSINIT(vnet_mld_init, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_init,
 3285     NULL);
 3286 
 3287 static void
 3288 vnet_mld_uninit(const void *unused __unused)
 3289 {
 3290 
 3291         /* This can happen if we shutdown the network stack. */
 3292         CTR1(KTR_MLD, "%s: tearing down", __func__);
 3293 }
 3294 VNET_SYSUNINIT(vnet_mld_uninit, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mld_uninit,
 3295     NULL);
 3296 
 3297 static int
 3298 mld_modevent(module_t mod, int type, void *unused __unused)
 3299 {
 3300 
 3301     switch (type) {
 3302     case MOD_LOAD:
 3303     case MOD_UNLOAD:
 3304         break;
 3305     default:
 3306         return (EOPNOTSUPP);
 3307     }
 3308     return (0);
 3309 }
 3310 
 3311 static moduledata_t mld_mod = {
 3312     "mld",
 3313     mld_modevent,
 3314     0
 3315 };
 3316 DECLARE_MODULE(mld, mld_mod, SI_SUB_PROTO_MC, SI_ORDER_ANY);

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