Annotation of src/sys/netinet6/mld6.c, Revision 1.2.2.2
1.2.2.2 ! thorpej 1: /*
! 2: * Copyright (C) 1998 WIDE Project.
! 3: * All rights reserved.
! 4: *
! 5: * Redistribution and use in source and binary forms, with or without
! 6: * modification, are permitted provided that the following conditions
! 7: * are met:
! 8: * 1. Redistributions of source code must retain the above copyright
! 9: * notice, this list of conditions and the following disclaimer.
! 10: * 2. Redistributions in binary form must reproduce the above copyright
! 11: * notice, this list of conditions and the following disclaimer in the
! 12: * documentation and/or other materials provided with the distribution.
! 13: * 3. Neither the name of the project nor the names of its contributors
! 14: * may be used to endorse or promote products derived from this software
! 15: * without specific prior written permission.
! 16: *
! 17: * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
! 18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 20: * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
! 21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 27: * SUCH DAMAGE.
! 28: */
! 29:
! 30: /*
! 31: * Copyright (c) 1988 Stephen Deering.
! 32: * Copyright (c) 1992, 1993
! 33: * The Regents of the University of California. All rights reserved.
! 34: *
! 35: * This code is derived from software contributed to Berkeley by
! 36: * Stephen Deering of Stanford University.
! 37: *
! 38: * Redistribution and use in source and binary forms, with or without
! 39: * modification, are permitted provided that the following conditions
! 40: * are met:
! 41: * 1. Redistributions of source code must retain the above copyright
! 42: * notice, this list of conditions and the following disclaimer.
! 43: * 2. Redistributions in binary form must reproduce the above copyright
! 44: * notice, this list of conditions and the following disclaimer in the
! 45: * documentation and/or other materials provided with the distribution.
! 46: * 3. All advertising materials mentioning features or use of this software
! 47: * must display the following acknowledgement:
! 48: * This product includes software developed by the University of
! 49: * California, Berkeley and its contributors.
! 50: * 4. Neither the name of the University nor the names of its contributors
! 51: * may be used to endorse or promote products derived from this software
! 52: * without specific prior written permission.
! 53: *
! 54: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 55: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 56: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 57: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 58: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 59: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 60: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 61: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 62: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 63: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 64: * SUCH DAMAGE.
! 65: *
! 66: * @(#)igmp.c 8.1 (Berkeley) 7/19/93
! 67: */
! 68:
! 69: #if (defined(__FreeBSD__) && __FreeBSD__ >= 3) || defined(__NetBSD__)
! 70: #include "opt_inet.h"
! 71: #endif
! 72:
! 73: #include <sys/param.h>
! 74: #include <sys/systm.h>
! 75: #include <sys/mbuf.h>
! 76: #include <sys/socket.h>
! 77: #include <sys/protosw.h>
! 78: #include <sys/syslog.h>
! 79:
! 80: #include <net/if.h>
! 81:
! 82: #include <netinet/in.h>
! 83: #include <netinet/in_var.h>
! 84: #include <netinet6/in6.h>
! 85: #include <netinet6/ip6.h>
! 86: #include <netinet6/ip6_var.h>
! 87: #include <netinet6/icmp6.h>
! 88: #include <netinet6/mld6_var.h>
! 89:
! 90: /*
! 91: * Protocol constants
! 92: */
! 93:
! 94: /* denotes that the MLD max response delay field specifies time in milliseconds */
! 95: #define MLD6_TIMER_SCALE 1000
! 96: /*
! 97: * time between repetitions of a node's initial report of interest in a
! 98: * multicast address(in seconds)
! 99: */
! 100: #define MLD6_UNSOLICITED_REPORT_INTERVAL 10
! 101:
! 102: static struct ip6_pktopts ip6_opts;
! 103: static int mld6_timers_are_running;
! 104: /* XXX: These are necessary for KAME's link-local hack */
! 105: static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
! 106: static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
! 107:
! 108: static void mld6_sendpkt __P((struct in6_multi *, int, const struct in6_addr *));
! 109:
! 110: void
! 111: mld6_init()
! 112: {
! 113: static u_int8_t hbh_buf[8];
! 114: struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
! 115: u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
! 116:
! 117: mld6_timers_are_running = 0;
! 118:
! 119: /* ip6h_nxt will be fill in later */
! 120: hbh->ip6h_len = 0; /* (8 >> 3) - 1*/
! 121:
! 122: /* XXX: grotty hard coding... */
! 123: hbh_buf[2] = IP6OPT_PADN; /* 2 byte padding */
! 124: hbh_buf[3] = 0;
! 125: hbh_buf[4] = IP6OPT_RTALERT;
! 126: hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
! 127: bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
! 128:
! 129: ip6_opts.ip6po_hbh = hbh;
! 130: /* We will specify the hoplimit by a multicast option. */
! 131: ip6_opts.ip6po_hlim = -1;
! 132: }
! 133:
! 134: void
! 135: mld6_start_listening(in6m)
! 136: struct in6_multi *in6m;
! 137: {
! 138: int s = splnet();
! 139:
! 140: /*
! 141: * (draft-ietf-ipngwg-mld, page 10)
! 142: * The node never sends a Report or Done for the link-scope all-nodes
! 143: * address.
! 144: * MLD messages are never sent for multicast addresses whose scope is 0
! 145: * (reserved) or 1 (node-local).
! 146: */
! 147: mld6_all_nodes_linklocal.s6_addr16[1] =
! 148: htons(in6m->in6m_ifp->if_index); /* XXX */
! 149: if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
! 150: IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
! 151: in6m->in6m_timer = 0;
! 152: in6m->in6m_state = MLD6_OTHERLISTENER;
! 153: } else {
! 154: mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
! 155: in6m->in6m_timer = MLD6_RANDOM_DELAY(
! 156: MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
! 157: in6m->in6m_state = MLD6_IREPORTEDLAST;
! 158: mld6_timers_are_running = 1;
! 159: }
! 160: splx(s);
! 161: }
! 162:
! 163: void
! 164: mld6_stop_listening(in6m)
! 165: struct in6_multi *in6m;
! 166: {
! 167: mld6_all_nodes_linklocal.s6_addr16[1] =
! 168: htons(in6m->in6m_ifp->if_index); /* XXX */
! 169: mld6_all_routers_linklocal.s6_addr16[1] =
! 170: htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
! 171:
! 172: if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
! 173: (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
! 174: IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
! 175: mld6_sendpkt(in6m, MLD6_LISTENER_DONE,
! 176: &mld6_all_routers_linklocal);
! 177: }
! 178:
! 179: void
! 180: mld6_input(m, off)
! 181: struct mbuf *m;
! 182: int off;
! 183: {
! 184: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
! 185: struct mld6_hdr *mldh = (struct mld6_hdr *)(mtod(m, caddr_t) + off);
! 186: struct ifnet *ifp = m->m_pkthdr.rcvif;
! 187: struct in6_multi *in6m;
! 188: struct in6_ifaddr *ia;
! 189: int timer; /* timer value in the MLD query header */
! 190:
! 191: /* source address validation */
! 192: if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
! 193: log(LOG_ERR,
! 194: "mld6_input: src %s is not link-local\n",
! 195: ip6_sprintf(&ip6->ip6_src));
! 196: /*
! 197: * spec(draft-ietf-ipngwg-mld) does not explicitly
! 198: * specify to discard the packet from a non link-local
! 199: * source address. But we believe it's expected to do so.
! 200: */
! 201: return;
! 202: }
! 203:
! 204: /*
! 205: * In the MLD6 specification, there are 3 states and a flag.
! 206: *
! 207: * In Non-Listener state, we simply don't have a membership record.
! 208: * In Delaying Listener state, our timer is running (in6m->in6m_timer)
! 209: * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
! 210: *
! 211: * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
! 212: * we have heard a report from another member, or MLD6_IREPORTEDLAST
! 213: * if we sent the last report.
! 214: */
! 215: switch(mldh->mld6_type) {
! 216: case MLD6_LISTENER_QUERY:
! 217: if (ifp->if_flags & IFF_LOOPBACK)
! 218: break;
! 219:
! 220: if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) &&
! 221: !IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
! 222: break; /* print error or log stat? */
! 223: if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
! 224: mldh->mld6_addr.s6_addr16[1] =
! 225: htons(ifp->if_index); /* XXX */
! 226:
! 227: /*
! 228: * - Start the timers in all of our membership records
! 229: * that the query applies to for the interface on
! 230: * which the query arrived excl. those that belong
! 231: * to the "all-nodes" group (ff02::1).
! 232: * - Restart any timer that is already running but has
! 233: * A value longer than the requested timeout.
! 234: * - Use the value specified in the query message as
! 235: * the maximum timeout.
! 236: */
! 237: IFP_TO_IA6(ifp, ia);
! 238: if (ia == NULL)
! 239: break;
! 240:
! 241: /*
! 242: * XXX: System timer resolution is too low to handle Max
! 243: * Response Delay, so set 1 to the internal timer even if
! 244: * the calculated value equals to zero when Max Response
! 245: * Delay is positive.
! 246: */
! 247: timer = ntohs(mldh->mld6_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
! 248: if (timer == 0 && mldh->mld6_maxdelay)
! 249: timer = 1;
! 250: mld6_all_nodes_linklocal.s6_addr16[1] =
! 251: htons(ifp->if_index); /* XXX */
! 252:
! 253: for (in6m = ia->ia6_multiaddrs.lh_first;
! 254: in6m;
! 255: in6m = in6m->in6m_entry.le_next) {
! 256: if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
! 257: &mld6_all_nodes_linklocal) ||
! 258: IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
! 259: IPV6_ADDR_SCOPE_LINKLOCAL)
! 260: continue;
! 261:
! 262: if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld6_addr) ||
! 263: IN6_ARE_ADDR_EQUAL(&mldh->mld6_addr,
! 264: &in6m->in6m_addr)) {
! 265: if (timer == 0) {
! 266: /* send a report immediately */
! 267: mld6_sendpkt(in6m, MLD6_LISTENER_REPORT,
! 268: NULL);
! 269: in6m->in6m_timer = 0; /* reset timer */
! 270: in6m->in6m_state = MLD6_IREPORTEDLAST;
! 271: }
! 272: else if (in6m->in6m_timer == 0 || /*idle state*/
! 273: in6m->in6m_timer > timer) {
! 274: in6m->in6m_timer =
! 275: MLD6_RANDOM_DELAY(timer);
! 276: mld6_timers_are_running = 1;
! 277: }
! 278: }
! 279: }
! 280:
! 281: if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
! 282: mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
! 283: break;
! 284: case MLD6_LISTENER_REPORT:
! 285: /*
! 286: * For fast leave to work, we have to know that we are the
! 287: * last person to send a report for this group. Reports
! 288: * can potentially get looped back if we are a multicast
! 289: * router, so discard reports sourced by me.
! 290: * Note that it is impossible to check IFF_LOOPBACK flag of
! 291: * ifp for this purpose, since ip6_mloopback pass the physical
! 292: * interface to looutput.
! 293: */
! 294: if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
! 295: break;
! 296:
! 297: if (!IN6_IS_ADDR_MULTICAST(&mldh->mld6_addr))
! 298: break;
! 299:
! 300: if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
! 301: mldh->mld6_addr.s6_addr16[1] =
! 302: htons(ifp->if_index); /* XXX */
! 303: /*
! 304: * If we belong to the group being reported, stop
! 305: * our timer for that group.
! 306: */
! 307: IN6_LOOKUP_MULTI(mldh->mld6_addr, ifp, in6m);
! 308: if (in6m) {
! 309: in6m->in6m_timer = 0; /* transit to idle state */
! 310: in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
! 311: }
! 312:
! 313: if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
! 314: mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
! 315: break;
! 316: default: /* this is impossible */
! 317: log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld6_type);
! 318: break;
! 319: }
! 320: }
! 321:
! 322: void
! 323: mld6_fasttimeo()
! 324: {
! 325: register struct in6_multi *in6m;
! 326: struct in6_multistep step;
! 327: int s;
! 328:
! 329: /*
! 330: * Quick check to see if any work needs to be done, in order
! 331: * to minimize the overhead of fasttimo processing.
! 332: */
! 333: if (!mld6_timers_are_running)
! 334: return;
! 335:
! 336: s = splnet();
! 337: mld6_timers_are_running = 0;
! 338: IN6_FIRST_MULTI(step, in6m);
! 339: while (in6m != NULL) {
! 340: if (in6m->in6m_timer == 0) {
! 341: /* do nothing */
! 342: } else if (--in6m->in6m_timer == 0) {
! 343: mld6_sendpkt(in6m, MLD6_LISTENER_REPORT, NULL);
! 344: in6m->in6m_state = MLD6_IREPORTEDLAST;
! 345: } else {
! 346: mld6_timers_are_running = 1;
! 347: }
! 348: IN6_NEXT_MULTI(step, in6m);
! 349: }
! 350: splx(s);
! 351: }
! 352:
! 353: static void
! 354: mld6_sendpkt(in6m, type, dst)
! 355: struct in6_multi *in6m;
! 356: int type;
! 357: const struct in6_addr *dst;
! 358: {
! 359: struct mbuf *mh, *md;
! 360: struct mld6_hdr *mldh;
! 361: struct ip6_hdr *ip6;
! 362: struct ip6_moptions im6o;
! 363: struct in6_ifaddr *ia;
! 364: struct ifnet *ifp = in6m->in6m_ifp;
! 365:
! 366: /*
! 367: * At first, find a link local address on the outgoing interface
! 368: * to use as the source address of the MLD packet.
! 369: */
! 370: if ((ia = in6ifa_ifpforlinklocal(ifp)) == NULL)
! 371: return;
! 372:
! 373: /*
! 374: * Allocate mbufs to store ip6 header and MLD header.
! 375: * We allocate 2 mbufs and make chain in advance because
! 376: * it is more convenient when inserting the hop-by-hop option later.
! 377: */
! 378: MGETHDR(mh, M_DONTWAIT, MT_HEADER);
! 379: if (mh == NULL)
! 380: return;
! 381: MGET(md, M_DONTWAIT, MT_DATA);
! 382: if (md == NULL) {
! 383: m_free(mh);
! 384: return;
! 385: }
! 386: mh->m_next = md;
! 387:
! 388: #ifdef IPSEC
! 389: mh->m_pkthdr.rcvif = NULL;
! 390: #endif
! 391: mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld6_hdr);
! 392: mh->m_len = sizeof(struct ip6_hdr);
! 393: MH_ALIGN(mh, sizeof(struct ip6_hdr));
! 394:
! 395: /* fill in the ip6 header */
! 396: ip6 = mtod(mh, struct ip6_hdr *);
! 397: ip6->ip6_flow = 0;
! 398: ip6->ip6_vfc = IPV6_VERSION;
! 399: /* ip6_plen will be set later */
! 400: ip6->ip6_nxt = IPPROTO_ICMPV6;
! 401: /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
! 402: ip6->ip6_src = ia->ia_addr.sin6_addr;
! 403: ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
! 404:
! 405: /* fill in the MLD header */
! 406: md->m_len = sizeof(struct mld6_hdr);
! 407: mldh = mtod(md, struct mld6_hdr *);
! 408: mldh->mld6_type = type;
! 409: mldh->mld6_code = 0;
! 410: mldh->mld6_cksum = 0;
! 411: /* XXX: we assume the function will not be called for query messages */
! 412: mldh->mld6_maxdelay = 0;
! 413: mldh->mld6_reserved = 0;
! 414: mldh->mld6_addr = in6m->in6m_addr;
! 415: if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld6_addr))
! 416: mldh->mld6_addr.s6_addr16[1] = 0; /* XXX */
! 417: mldh->mld6_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
! 418: sizeof(struct mld6_hdr));
! 419:
! 420: /* construct multicast option */
! 421: bzero(&im6o, sizeof(im6o));
! 422: im6o.im6o_multicast_ifp = ifp;
! 423: im6o.im6o_multicast_hlim = 1;
! 424:
! 425: /*
! 426: * Request loopback of the report if we are acting as a multicast
! 427: * router, so that the process-level routing daemon can hear it.
! 428: */
! 429: im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
! 430:
! 431: /* increment output statictics */
! 432: icmp6stat.icp6s_outhist[type]++;
! 433:
! 434: ip6_output(mh, &ip6_opts, NULL, 0, &im6o);
! 435: }
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