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Annotation of src/sys/netinet6/mld6.c, Revision 1.10

1.10    ! itojun      1: /*     $NetBSD: mld6.c,v 1.9 2000/01/06 15:46:10 itojun Exp $  */
1.3       thorpej     2:
1.2       itojun      3: /*
                      4:  * Copyright (C) 1998 WIDE Project.
                      5:  * All rights reserved.
                      6:  *
                      7:  * Redistribution and use in source and binary forms, with or without
                      8:  * modification, are permitted provided that the following conditions
                      9:  * are met:
                     10:  * 1. Redistributions of source code must retain the above copyright
                     11:  *    notice, this list of conditions and the following disclaimer.
                     12:  * 2. Redistributions in binary form must reproduce the above copyright
                     13:  *    notice, this list of conditions and the following disclaimer in the
                     14:  *    documentation and/or other materials provided with the distribution.
                     15:  * 3. Neither the name of the project nor the names of its contributors
                     16:  *    may be used to endorse or promote products derived from this software
                     17:  *    without specific prior written permission.
                     18:  *
                     19:  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
                     20:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     21:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     22:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
                     23:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     24:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     25:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     26:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     27:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     28:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     29:  * SUCH DAMAGE.
                     30:  */
                     31:
                     32: /*
                     33:  * Copyright (c) 1988 Stephen Deering.
                     34:  * Copyright (c) 1992, 1993
                     35:  *     The Regents of the University of California.  All rights reserved.
                     36:  *
                     37:  * This code is derived from software contributed to Berkeley by
                     38:  * Stephen Deering of Stanford University.
                     39:  *
                     40:  * Redistribution and use in source and binary forms, with or without
                     41:  * modification, are permitted provided that the following conditions
                     42:  * are met:
                     43:  * 1. Redistributions of source code must retain the above copyright
                     44:  *    notice, this list of conditions and the following disclaimer.
                     45:  * 2. Redistributions in binary form must reproduce the above copyright
                     46:  *    notice, this list of conditions and the following disclaimer in the
                     47:  *    documentation and/or other materials provided with the distribution.
                     48:  * 3. All advertising materials mentioning features or use of this software
                     49:  *    must display the following acknowledgement:
                     50:  *     This product includes software developed by the University of
                     51:  *     California, Berkeley and its contributors.
                     52:  * 4. Neither the name of the University nor the names of its contributors
                     53:  *    may be used to endorse or promote products derived from this software
                     54:  *    without specific prior written permission.
                     55:  *
                     56:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     57:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     58:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     59:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     60:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     61:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     62:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     63:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     64:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     65:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     66:  * SUCH DAMAGE.
                     67:  *
                     68:  *     @(#)igmp.c      8.1 (Berkeley) 7/19/93
                     69:  */
                     70:
                     71: #include "opt_inet.h"
1.5       thorpej    72: #include "opt_ipsec.h"
1.2       itojun     73:
                     74: #include <sys/param.h>
                     75: #include <sys/systm.h>
                     76: #include <sys/mbuf.h>
                     77: #include <sys/socket.h>
                     78: #include <sys/protosw.h>
                     79: #include <sys/syslog.h>
                     80:
                     81: #include <net/if.h>
                     82:
                     83: #include <netinet/in.h>
                     84: #include <netinet/in_var.h>
1.10    ! itojun     85: #include <netinet/ip6.h>
1.2       itojun     86: #include <netinet6/ip6_var.h>
1.10    ! itojun     87: #include <netinet/icmp6.h>
1.2       itojun     88: #include <netinet6/mld6_var.h>
                     89:
1.7       itojun     90: #include <net/net_osdep.h>
                     91:
1.2       itojun     92: /*
                     93:  * Protocol constants
                     94:  */
                     95:
                     96: /* denotes that the MLD max response delay field specifies time in milliseconds */
                     97: #define MLD6_TIMER_SCALE       1000
                     98: /*
                     99:  * time between repetitions of a node's initial report of interest in a
                    100:  * multicast address(in seconds)
                    101:  */
                    102: #define MLD6_UNSOLICITED_REPORT_INTERVAL       10
                    103:
                    104: static struct ip6_pktopts ip6_opts;
                    105: static int mld6_timers_are_running;
                    106: /* XXX: These are necessary for KAME's link-local hack */
                    107: static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
                    108: static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
                    109:
                    110: static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *));
                    111:
                    112: void
                    113: mld6_init()
                    114: {
                    115:        static u_int8_t hbh_buf[8];
                    116:        struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
                    117:        u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
                    118:
                    119:        mld6_timers_are_running = 0;
                    120:
                    121:        /* ip6h_nxt will be fill in later */
                    122:        hbh->ip6h_len = 0;      /* (8 >> 3) - 1*/
                    123:
                    124:        /* XXX: grotty hard coding... */
                    125:        hbh_buf[2] = IP6OPT_PADN;       /* 2 byte padding */
                    126:        hbh_buf[3] = 0;
                    127:        hbh_buf[4] = IP6OPT_RTALERT;
                    128:        hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
                    129:        bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
                    130:
                    131:        ip6_opts.ip6po_hbh = hbh;
                    132:        /* We will specify the hoplimit by a multicast option. */
                    133:        ip6_opts.ip6po_hlim = -1;
                    134: }
                    135:
                    136: void
                    137: mld6_start_listening(in6m)
                    138:        struct in6_multi *in6m;
                    139: {
1.4       itojun    140:        int s = splsoftnet();
1.2       itojun    141:
                    142:        /*
                    143:         * (draft-ietf-ipngwg-mld, page 10)
                    144:         * The node never sends a Report or Done for the link-scope all-nodes
                    145:         * address.
                    146:         * MLD messages are never sent for multicast addresses whose scope is 0
                    147:         * (reserved) or 1 (node-local).
                    148:         */
                    149:        mld6_all_nodes_linklocal.s6_addr16[1] =
                    150:                htons(in6m->in6m_ifp->if_index); /* XXX */
                    151:        if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
                    152:            IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
                    153:                in6m->in6m_timer = 0;
                    154:                in6m->in6m_state = MLD6_OTHERLISTENER;
                    155:        } else {
                    156:                mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
                    157:                in6m->in6m_timer = MLD6_RANDOM_DELAY(
                    158:                        MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
                    159:                in6m->in6m_state = MLD6_IREPORTEDLAST;
                    160:                mld6_timers_are_running = 1;
                    161:        }
                    162:        splx(s);
                    163: }
                    164:
                    165: void
                    166: mld6_stop_listening(in6m)
                    167:        struct in6_multi *in6m;
                    168: {
                    169:        mld6_all_nodes_linklocal.s6_addr16[1] =
                    170:                htons(in6m->in6m_ifp->if_index); /* XXX */
                    171:        mld6_all_routers_linklocal.s6_addr16[1] =
                    172:                htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
                    173:
                    174:        if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
                    175:            (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
                    176:            IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
                    177:                mld6_sendpkt(in6m, MLD6_LISTENER_DONE,
                    178:                             &mld6_all_routers_linklocal);
                    179: }
                    180:
                    181: void
                    182: mld6_input(m, off)
                    183:        struct mbuf *m;
                    184:        int off;
                    185: {
                    186:        struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
                    187:        struct mld6_hdr *mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off);
                    188:        struct ifnet *ifp = m->m_pkthdr.rcvif;
                    189:        struct in6_multi *in6m;
                    190:        struct in6_ifaddr *ia;
                    191:        int timer;              /* timer value in the MLD query header */
                    192:
                    193:        /* source address validation */
                    194:        if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
                    195:                log(LOG_ERR,
                    196:                    "mld6_input: src %s is not link-local\n",
                    197:                    ip6_sprintf(&ip6->ip6_src));
                    198:                /*
                    199:                 * spec(draft-ietf-ipngwg-mld) does not explicitly
                    200:                 * specify to discard the packet from a non link-local
                    201:                 * source address. But we believe it's expected to do so.
                    202:                 */
                    203:                return;
                    204:        }
                    205:
                    206:        /*
                    207:         * In the MLD6 specification, there are 3 states and a flag.
                    208:         *
                    209:         * In Non-Listener state, we simply don't have a membership record.
                    210:         * In Delaying Listener state, our timer is running (in6m->in6m_timer)
                    211:         * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
                    212:         *
                    213:         * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
                    214:         * we have heard a report from another member, or MLD6_IREPORTEDLAST
                    215:         * if we sent the last report.
                    216:         */
                    217:        switch(mldh->mld6_type) {
1.7       itojun    218:        case MLD6_LISTENER_QUERY:
                    219:                if (ifp->if_flags & IFF_LOOPBACK)
                    220:                        break;
                    221:
                    222:                if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) &&
                    223:                !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
                    224:                        break;  /* print error or log stat? */
                    225:                if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
                    226:                        mldh->mld6_addr.s6_addr16[1] =
                    227:                                htons(ifp->if_index); /* XXX */
1.2       itojun    228:
1.7       itojun    229:                /*
                    230:                * - Start the timers in all of our membership records
                    231:                *   that the query applies to for the interface on
                    232:                *   which the query arrived excl. those that belong
                    233:                *   to the "all-nodes" group (ff02::1).
                    234:                * - Restart any timer that is already running but has
                    235:                *   A value longer than the requested timeout.
                    236:                * - Use the value specified in the query message as
                    237:                *   the maximum timeout.
                    238:                */
                    239:                IFP_TO_IA6(ifp, ia);
                    240:                if (ia == NULL)
                    241:                        break;
1.2       itojun    242:
                    243:                /*
1.7       itojun    244:                * XXX: System timer resolution is too low to handle Max
                    245:                * Response Delay, so set 1 to the internal timer even if
                    246:                * the calculated value equals to zero when Max Response
                    247:                * Delay is positive.
                    248:                */
                    249:                timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
                    250:                if (timer == 0 && mldh->mld6_maxdelay)
                    251:                        timer = 1;
                    252:                mld6_all_nodes_linklocal.s6_addr16[1] =
                    253:                        htons(ifp->if_index); /* XXX */
                    254:
                    255:                for (in6m = ia->ia6_multiaddrs.lh_first;
                    256:                     in6m;
                    257:                     in6m = in6m->in6m_entry.le_next)
                    258:                {
                    259:                        if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
1.2       itojun    260:                                                &mld6_all_nodes_linklocal) ||
1.7       itojun    261:                            IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
                    262:                            IPV6_ADDR_SCOPE_LINKLOCAL)
                    263:                                continue;
1.2       itojun    264:
1.7       itojun    265:                        if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) ||
                    266:                            IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr,
                    267:                                                &in6m->in6m_addr))
                    268:                        {
                    269:                                if (timer == 0) {
                    270:                                        /* send a report immediately */
                    271:                                        mld6_sendpkt(in6m, MLD6_LISTENER_REPORT,
                    272:                                                NULL);
                    273:                                        in6m->in6m_timer = 0; /* reset timer */
                    274:                                        in6m->in6m_state = MLD6_IREPORTEDLAST;
                    275:                                }
                    276:                                else if (in6m->in6m_timer == 0 || /*idle state*/
                    277:                                        in6m->in6m_timer > timer) {
                    278:                                        in6m->in6m_timer =
                    279:                                                MLD6_RANDOM_DELAY(timer);
                    280:                                        mld6_timers_are_running = 1;
                    281:                                }
                    282:                        }
                    283:                }
1.2       itojun    284:
1.7       itojun    285:                if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
                    286:                        mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
                    287:                break;
                    288:        case MLD6_LISTENER_REPORT:
1.2       itojun    289:                /*
1.7       itojun    290:                * For fast leave to work, we have to know that we are the
                    291:                * last person to send a report for this group.  Reports
                    292:                * can potentially get looped back if we are a multicast
                    293:                * router, so discard reports sourced by me.
                    294:                * Note that it is impossible to check IFF_LOOPBACK flag of
                    295:                * ifp for this purpose, since ip6_mloopback pass the physical
                    296:                * interface to looutput.
                    297:                */
                    298:                if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
                    299:                        break;
                    300:
                    301:                if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
                    302:                        break;
                    303:
                    304:                if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
                    305:                        mldh->mld6_addr.s6_addr16[1] =
                    306:                                htons(ifp->if_index); /* XXX */
                    307:                /*
                    308:                * If we belong to the group being reported, stop
                    309:                * our timer for that group.
                    310:                */
                    311:                IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m);
                    312:                if (in6m) {
                    313:                        in6m->in6m_timer = 0; /* transit to idle state */
                    314:                        in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
                    315:                }
                    316:
                    317:                if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
                    318:                        mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
                    319:                break;
                    320:        default:                /* this is impossible */
                    321:                log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type);
                    322:                break;
1.2       itojun    323:        }
                    324: }
                    325:
                    326: void
                    327: mld6_fasttimeo()
                    328: {
                    329:        register struct in6_multi *in6m;
                    330:        struct in6_multistep step;
                    331:        int s;
                    332:
                    333:        /*
                    334:         * Quick check to see if any work needs to be done, in order
                    335:         * to minimize the overhead of fasttimo processing.
                    336:         */
                    337:        if (!mld6_timers_are_running)
                    338:                return;
                    339:
1.4       itojun    340:        s = splsoftnet();
1.2       itojun    341:        mld6_timers_are_running = 0;
                    342:        IN6_FIRST_MULTI(step, in6m);
                    343:        while (in6m != NULL) {
                    344:                if (in6m->in6m_timer == 0) {
                    345:                        /* do nothing */
                    346:                } else if (--in6m->in6m_timer == 0) {
                    347:                        mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
                    348:                        in6m->in6m_state = MLD6_IREPORTEDLAST;
                    349:                } else {
                    350:                        mld6_timers_are_running = 1;
                    351:                }
                    352:                IN6_NEXT_MULTI(step, in6m);
                    353:        }
                    354:        splx(s);
                    355: }
                    356:
                    357: static void
                    358: mld6_sendpkt(in6m, type, dst)
                    359:        struct in6_multi *in6m;
                    360:        int type;
                    361:        const struct in6_addr *dst;
                    362: {
                    363:        struct mbuf *mh, *md;
                    364:        struct mld6_hdr *mldh;
                    365:        struct ip6_hdr *ip6;
                    366:        struct ip6_moptions im6o;
                    367:        struct in6_ifaddr *ia;
                    368:        struct ifnet *ifp = in6m->in6m_ifp;
1.7       itojun    369:        struct ifnet *outif = NULL;
1.2       itojun    370:
                    371:        /*
                    372:         * At first, find a link local address on the outgoing interface
                    373:         * to use as the source address of the MLD packet.
                    374:         */
                    375:        if ((ia = in6ifa_ifpforlinklocal(ifp)) == NULL)
                    376:                return;
                    377:
                    378:        /*
                    379:         * Allocate mbufs to store ip6 header and MLD header.
                    380:         * We allocate 2 mbufs and make chain in advance because
                    381:         * it is more convenient when inserting the hop-by-hop option later.
                    382:         */
                    383:        MGETHDR(mh, M_DONTWAIT, MT_HEADER);
                    384:        if (mh == NULL)
                    385:                return;
                    386:        MGET(md, M_DONTWAIT, MT_DATA);
                    387:        if (md == NULL) {
                    388:                m_free(mh);
                    389:                return;
                    390:        }
                    391:        mh->m_next = md;
                    392:
                    393: #ifdef IPSEC
                    394:        mh->m_pkthdr.rcvif = NULL;
                    395: #endif
                    396:        mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr);
                    397:        mh->m_len = sizeof(struct ip6_hdr);
                    398:        MH_ALIGN(mh, sizeof(struct ip6_hdr));
                    399:
                    400:        /* fill in the ip6 header */
                    401:        ip6 = mtod(mh, struct ip6_hdr *);
                    402:        ip6->ip6_flow = 0;
1.8       itojun    403:        ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
                    404:        ip6->ip6_vfc |= IPV6_VERSION;
1.2       itojun    405:        /* ip6_plen will be set later */
                    406:        ip6->ip6_nxt = IPPROTO_ICMPV6;
                    407:        /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
                    408:        ip6->ip6_src = ia->ia_addr.sin6_addr;
                    409:        ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
                    410:
                    411:        /* fill in the MLD header */
                    412:        md->m_len = sizeof(struct mld6_hdr);
                    413:        mldh = mtod(md, struct mld6_hdr *);
                    414:        mldh->mld6_type = type;
                    415:        mldh->mld6_code = 0;
                    416:        mldh->mld6_cksum = 0;
                    417:        /* XXX: we assume the function will not be called for query messages */
                    418:        mldh->mld6_maxdelay = 0;
                    419:        mldh->mld6_reserved = 0;
                    420:        mldh->mld6_addr = in6m->in6m_addr;
                    421:        if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
                    422:                mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
                    423:        mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
                    424:                                     sizeof(struct mld6_hdr));
                    425:
                    426:        /* construct multicast option */
                    427:        bzero(&im6o, sizeof(im6o));
                    428:        im6o.im6o_multicast_ifp = ifp;
                    429:        im6o.im6o_multicast_hlim = 1;
                    430:
                    431:        /*
                    432:         * Request loopback of the report if we are acting as a multicast
                    433:         * router, so that the process-level routing daemon can hear it.
                    434:         */
                    435:        im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
                    436:
                    437:        /* increment output statictics */
                    438:        icmp6stat.icp6s_outhist[type]++;
                    439:
1.7       itojun    440:        ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif);
                    441:        if (outif) {
                    442:                icmp6_ifstat_inc(outif, ifs6_out_msg);
                    443:                switch(type) {
                    444:                 case MLD6_LISTENER_QUERY:
                    445:                         icmp6_ifstat_inc(outif, ifs6_out_mldquery);
                    446:                         break;
                    447:                 case MLD6_LISTENER_REPORT:
                    448:                         icmp6_ifstat_inc(outif, ifs6_out_mldreport);
                    449:                         break;
                    450:                 case MLD6_LISTENER_DONE:
                    451:                         icmp6_ifstat_inc(outif, ifs6_out_mlddone);
                    452:                         break;
                    453:                }
                    454:        }
1.2       itojun    455: }

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