bfdd/bfd_packet.c

   1 /*********************************************************************
   2  * Copyright 2017 Cumulus Networks, Inc.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; either version 2 of the License, or (at your option)
   7  * any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; see the file COPYING; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  17  *
  18  * bfd_packet.c: implements the BFD protocol packet handling.
  19  *
  20  * Authors
  21  * -------
  22  * Shrijeet Mukherjee [shm@cumulusnetworks.com]
  23  * Kanna Rajagopal [kanna@cumulusnetworks.com]
  24  * Radhika Mahankali [Radhika@cumulusnetworks.com]
  25  */
  26
  27 #include <zebra.h>
  28
  29 #ifdef BFD_LINUX
  30 #include <linux/if_packet.h>
  31 #endif /* BFD_LINUX */
  32
  33 #include <netinet/if_ether.h>
  34 #include <netinet/udp.h>
  35
  36 #include "lib/sockopt.h"
  37
  38 #include "bfd.h"
  39
  40
  41 /*
  42  * Prototypes
  43  */
  44 static int ptm_bfd_process_echo_pkt(int s);
  45 int _ptm_bfd_send(struct bfd_session *bs, uint16_t *port, const void *data,
  46                   size_t datalen);
  47
  48 static void bfd_sd_reschedule(int sd);
  49 ssize_t bfd_recv_ipv4(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
  50                       char *port, size_t portlen, char *vrfname,
  51                       size_t vrfnamelen, struct sockaddr_any *local,
  52                       struct sockaddr_any *peer);
  53 ssize_t bfd_recv_ipv6(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
  54                       char *port, size_t portlen, char *vrfname,
  55                       size_t vrfnamelen, struct sockaddr_any *local,
  56                       struct sockaddr_any *peer);
  57 int bp_udp_send(int sd, uint8_t ttl, uint8_t *data, size_t datalen,
  58                 struct sockaddr *to, socklen_t tolen);
  59 int bp_bfd_echo_in(int sd, uint8_t *ttl, uint32_t *my_discr);
  60
  61 /* socket related prototypes */
  62 static void bp_set_ipopts(int sd);
  63 static void bp_bind_ip(int sd, uint16_t port);
  64 static void bp_set_ipv6opts(int sd);
  65 static void bp_bind_ipv6(int sd, uint16_t port);
  66
  67
  68 /*
  69  * Functions
  70  */
  71 int _ptm_bfd_send(struct bfd_session *bs, uint16_t *port, const void *data,
  72                   size_t datalen)
  73 {
  74         struct sockaddr *sa;
  75         struct sockaddr_in sin;
  76         struct sockaddr_in6 sin6;
  77         socklen_t slen;
  78         ssize_t rv;
  79         int sd = -1;
  80
  81         if (BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_IPV6)) {
  82                 memset(&sin6, 0, sizeof(sin6));
  83                 sin6.sin6_family = AF_INET6;
  84                 sin6.sin6_addr = bs->shop.peer.sa_sin6.sin6_addr;
  85                 sin6.sin6_port =
  86                         (port) ? *port
  87                                : (BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_MH))
  88                                          ? htons(BFD_DEF_MHOP_DEST_PORT)
  89                                          : htons(BFD_DEFDESTPORT);
  90
  91                 sd = bs->sock;
  92                 sa = (struct sockaddr *)&sin6;
  93                 slen = sizeof(sin6);
  94         } else {
  95                 memset(&sin, 0, sizeof(sin));
  96                 sin.sin_family = AF_INET;
  97                 sin.sin_addr = bs->shop.peer.sa_sin.sin_addr;
  98                 sin.sin_port =
  99                         (port) ? *port
 100                                : (BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_MH))
 101                                          ? htons(BFD_DEF_MHOP_DEST_PORT)
 102                                          : htons(BFD_DEFDESTPORT);
 103
 104                 sd = bs->sock;
 105                 sa = (struct sockaddr *)&sin;
 106                 slen = sizeof(sin);
 107         }
 108
 109 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
 110         sa->sa_len = slen;
 111 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
 112         rv = sendto(sd, data, datalen, 0, sa, slen);
 113         if (rv <= 0) {
 114                 log_debug("packet-send: send failure: %s", strerror(errno));
 115                 return -1;
 116         }
 117         if (rv < (ssize_t)datalen)
 118                 log_debug("packet-send: send partial", strerror(errno));
 119
 120         return 0;
 121 }
 122
 123 void ptm_bfd_echo_snd(struct bfd_session *bfd)
 124 {
 125         struct sockaddr_any *sa;
 126         socklen_t salen;
 127         int sd;
 128         struct bfd_echo_pkt bep;
 129         struct sockaddr_in sin;
 130         struct sockaddr_in6 sin6;
 131
 132         if (!BFD_CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE))
 133                 BFD_SET_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE);
 134
 135         memset(&bep, 0, sizeof(bep));
 136         bep.ver = BFD_ECHO_VERSION;
 137         bep.len = BFD_ECHO_PKT_LEN;
 138         bep.my_discr = htonl(bfd->discrs.my_discr);
 139
 140         sa = BFD_CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_MH) ? &bfd->mhop.peer
 141                                                           : &bfd->shop.peer;
 142         if (BFD_CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_IPV6)) {
 143                 sd = bglobal.bg_echov6;
 144                 sin6 = sa->sa_sin6;
 145                 sin6.sin6_port = htons(BFD_DEF_ECHO_PORT);
 146 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
 147                 sin6.sin6_len = sizeof(sin6);
 148 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
 149
 150                 sa = (struct sockaddr_any *)&sin6;
 151                 salen = sizeof(sin6);
 152         } else {
 153                 sd = bglobal.bg_echo;
 154                 sin = sa->sa_sin;
 155                 sin.sin_port = htons(BFD_DEF_ECHO_PORT);
 156 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
 157                 sin.sin_len = sizeof(sin);
 158 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
 159
 160                 sa = (struct sockaddr_any *)&sin;
 161                 salen = sizeof(sin);
 162         }
 163         if (bp_udp_send(sd, BFD_TTL_VAL, (uint8_t *)&bep, sizeof(bep),
 164                         (struct sockaddr *)sa, salen)
 165             == -1)
 166                 return;
 167
 168         bfd->stats.tx_echo_pkt++;
 169 }
 170
 171 static int ptm_bfd_process_echo_pkt(int s)
 172 {
 173         struct bfd_session *bfd;
 174         uint32_t my_discr = 0;
 175         uint8_t ttl = 0;
 176
 177         /* Receive and parse echo packet. */
 178         if (bp_bfd_echo_in(s, &ttl, &my_discr) == -1)
 179                 return 0;
 180
 181         /* Your discriminator not zero - use it to find session */
 182         bfd = bfd_id_lookup(my_discr);
 183         if (bfd == NULL) {
 184                 log_debug("echo-packet: no matching session (id:%u)", my_discr);
 185                 return -1;
 186         }
 187
 188         if (!BFD_CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE)) {
 189                 log_debug("echo-packet: echo disabled [%s] (id:%u)",
 190                           bs_to_string(bfd), my_discr);
 191                 return -1;
 192         }
 193
 194         bfd->stats.rx_echo_pkt++;
 195
 196         /* Compute detect time */
 197         bfd->echo_detect_TO = bfd->remote_detect_mult * bfd->echo_xmt_TO;
 198
 199         /* Update echo receive timeout. */
 200         bfd_echo_recvtimer_update(bfd);
 201
 202         return 0;
 203 }
 204
 205 void ptm_bfd_snd(struct bfd_session *bfd, int fbit)
 206 {
 207         struct bfd_pkt cp;
 208
 209         /* Set fields according to section 6.5.7 */
 210         cp.diag = bfd->local_diag;
 211         BFD_SETVER(cp.diag, BFD_VERSION);
 212         cp.flags = 0;
 213         BFD_SETSTATE(cp.flags, bfd->ses_state);
 214         BFD_SETDEMANDBIT(cp.flags, BFD_DEF_DEMAND);
 215         BFD_SETPBIT(cp.flags, bfd->polling);
 216         BFD_SETFBIT(cp.flags, fbit);
 217         cp.detect_mult = bfd->detect_mult;
 218         cp.len = BFD_PKT_LEN;
 219         cp.discrs.my_discr = htonl(bfd->discrs.my_discr);
 220         cp.discrs.remote_discr = htonl(bfd->discrs.remote_discr);
 221         if (bfd->polling) {
 222                 cp.timers.desired_min_tx =
 223                         htonl(bfd->new_timers.desired_min_tx);
 224                 cp.timers.required_min_rx =
 225                         htonl(bfd->new_timers.required_min_rx);
 226         } else {
 227                 cp.timers.desired_min_tx = htonl(bfd->timers.desired_min_tx);
 228                 cp.timers.required_min_rx = htonl(bfd->timers.required_min_rx);
 229         }
 230         cp.timers.required_min_echo = htonl(bfd->timers.required_min_echo);
 231
 232         if (_ptm_bfd_send(bfd, NULL, &cp, BFD_PKT_LEN) != 0)
 233                 return;
 234
 235         bfd->stats.tx_ctrl_pkt++;
 236 }
 237
 238 ssize_t bfd_recv_ipv4(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
 239                       char *port, size_t portlen, char *vrfname,
 240                       size_t vrfnamelen, struct sockaddr_any *local,
 241                       struct sockaddr_any *peer)
 242 {
 243         struct cmsghdr *cm;
 244         int ifindex;
 245         ssize_t mlen;
 246         struct sockaddr_in msgaddr;
 247         struct msghdr msghdr;
 248         struct iovec iov[1];
 249         uint8_t cmsgbuf[255];
 250
 251         port[0] = '\0';
 252
 253         /* Prepare the recvmsg params. */
 254         iov[0].iov_base = msgbuf;
 255         iov[0].iov_len = msgbuflen;
 256
 257         memset(&msghdr, 0, sizeof(msghdr));
 258         msghdr.msg_name = &msgaddr;
 259         msghdr.msg_namelen = sizeof(msgaddr);
 260         msghdr.msg_iov = iov;
 261         msghdr.msg_iovlen = 1;
 262         msghdr.msg_control = cmsgbuf;
 263         msghdr.msg_controllen = sizeof(cmsgbuf);
 264
 265         mlen = recvmsg(sd, &msghdr, MSG_DONTWAIT);
 266         if (mlen == -1) {
 267                 if (errno != EAGAIN)
 268                         log_error("ipv4-recv: recv failed: %s",
 269                                   strerror(errno));
 270
 271                 return -1;
 272         }
 273
 274         /* Get source address */
 275         peer->sa_sin = *((struct sockaddr_in *)(msghdr.msg_name));
 276
 277         /* Get and check TTL */
 278         for (cm = CMSG_FIRSTHDR(&msghdr); cm != NULL;
 279              cm = CMSG_NXTHDR(&msghdr, cm)) {
 280                 if (cm->cmsg_level != IPPROTO_IP)
 281                         continue;
 282
 283                 switch (cm->cmsg_type) {
 284 #ifdef BFD_LINUX
 285                 case IP_TTL: {
 286                         uint32_t ttlval;
 287
 288                         memcpy(&ttlval, CMSG_DATA(cm), sizeof(ttlval));
 289                         if (ttlval > 255) {
 290                                 log_debug("ipv4-recv: invalid TTL: %u", ttlval);
 291                                 return -1;
 292                         }
 293                         *ttl = ttlval;
 294                         break;
 295                 }
 296
 297                 case IP_PKTINFO: {
 298                         struct in_pktinfo *pi =
 299                                 (struct in_pktinfo *)CMSG_DATA(cm);
 300
 301                         if (pi == NULL)
 302                                 break;
 303
 304                         local->sa_sin.sin_family = AF_INET;
 305                         local->sa_sin.sin_addr = pi->ipi_addr;
 306                         fetch_portname_from_ifindex(pi->ipi_ifindex, port,
 307                                                     portlen);
 308                         break;
 309                 }
 310 #endif /* BFD_LINUX */
 311 #ifdef BFD_BSD
 312                 case IP_RECVTTL: {
 313                         memcpy(ttl, CMSG_DATA(cm), sizeof(*ttl));
 314                         break;
 315                 }
 316
 317                 case IP_RECVDSTADDR: {
 318                         struct in_addr ia;
 319
 320                         memcpy(&ia, CMSG_DATA(cm), sizeof(ia));
 321                         local->sa_sin.sin_family = AF_INET;
 322                         local->sa_sin.sin_addr = ia;
 323                         break;
 324                 }
 325 #endif /* BFD_BSD */
 326
 327                 default:
 328                         /*
 329                          * On *BSDs we expect to land here when skipping
 330                          * the IP_RECVIF header. It will be handled by
 331                          * getsockopt_ifindex() below.
 332                          */
 333                         /* NOTHING */
 334                         break;
 335                 }
 336         }
 337
 338         /* OS agnostic way of getting interface name. */
 339         if (port[0] == 0) {
 340                 ifindex = getsockopt_ifindex(AF_INET, &msghdr);
 341                 if (ifindex > 0)
 342                         fetch_portname_from_ifindex(ifindex, port, portlen);
 343         }
 344
 345         return mlen;
 346 }
 347
 348 ssize_t bfd_recv_ipv6(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
 349                       char *port, size_t portlen, char *vrfname,
 350                       size_t vrfnamelen, struct sockaddr_any *local,
 351                       struct sockaddr_any *peer)
 352 {
 353         struct cmsghdr *cm;
 354         struct in6_pktinfo *pi6 = NULL;
 355         int ifindex = 0;
 356         ssize_t mlen;
 357         uint32_t ttlval;
 358         struct sockaddr_in6 msgaddr6;
 359         struct msghdr msghdr6;
 360         struct iovec iov[1];
 361         uint8_t cmsgbuf6[255];
 362
 363         /* Prepare the recvmsg params. */
 364         iov[0].iov_base = msgbuf;
 365         iov[0].iov_len = msgbuflen;
 366
 367         memset(&msghdr6, 0, sizeof(msghdr6));
 368         msghdr6.msg_name = &msgaddr6;
 369         msghdr6.msg_namelen = sizeof(msgaddr6);
 370         msghdr6.msg_iov = iov;
 371         msghdr6.msg_iovlen = 1;
 372         msghdr6.msg_control = cmsgbuf6;
 373         msghdr6.msg_controllen = sizeof(cmsgbuf6);
 374
 375         mlen = recvmsg(sd, &msghdr6, MSG_DONTWAIT);
 376         if (mlen == -1) {
 377                 if (errno != EAGAIN)
 378                         log_error("ipv6-recv: recv failed: %s",
 379                                   strerror(errno));
 380
 381                 return -1;
 382         }
 383
 384         /* Get source address */
 385         peer->sa_sin6 = *((struct sockaddr_in6 *)(msghdr6.msg_name));
 386
 387         /* Get and check TTL */
 388         for (cm = CMSG_FIRSTHDR(&msghdr6); cm != NULL;
 389              cm = CMSG_NXTHDR(&msghdr6, cm)) {
 390                 if (cm->cmsg_level != IPPROTO_IPV6)
 391                         continue;
 392
 393                 if (cm->cmsg_type == IPV6_HOPLIMIT) {
 394                         memcpy(&ttlval, CMSG_DATA(cm), sizeof(ttlval));
 395                         if (ttlval > 255) {
 396                                 log_debug("ipv6-recv: invalid TTL: %u", ttlval);
 397                                 return -1;
 398                         }
 399
 400                         *ttl = ttlval;
 401                 } else if (cm->cmsg_type == IPV6_PKTINFO) {
 402                         pi6 = (struct in6_pktinfo *)CMSG_DATA(cm);
 403                         if (pi6) {
 404                                 local->sa_sin.sin_family = AF_INET6;
 405                                 local->sa_sin6.sin6_addr = pi6->ipi6_addr;
 406                                 fetch_portname_from_ifindex(pi6->ipi6_ifindex,
 407                                                             port, portlen);
 408                                 ifindex = pi6->ipi6_ifindex;
 409                         }
 410                 }
 411         }
 412
 413         /* Set scope ID for link local addresses. */
 414         if (IN6_IS_ADDR_LINKLOCAL(&peer->sa_sin6.sin6_addr))
 415                 peer->sa_sin6.sin6_scope_id = ifindex;
 416         if (IN6_IS_ADDR_LINKLOCAL(&local->sa_sin6.sin6_addr))
 417                 local->sa_sin6.sin6_scope_id = ifindex;
 418
 419         return mlen;
 420 }
 421
 422 static void bfd_sd_reschedule(int sd)
 423 {
 424         if (sd == bglobal.bg_shop) {
 425                 THREAD_OFF(bglobal.bg_ev[0]);
 426                 thread_add_read(master, bfd_recv_cb, NULL, bglobal.bg_shop,
 427                                 &bglobal.bg_ev[0]);
 428         } else if (sd == bglobal.bg_mhop) {
 429                 THREAD_OFF(bglobal.bg_ev[1]);
 430                 thread_add_read(master, bfd_recv_cb, NULL, bglobal.bg_mhop,
 431                                 &bglobal.bg_ev[1]);
 432         } else if (sd == bglobal.bg_shop6) {
 433                 THREAD_OFF(bglobal.bg_ev[2]);
 434                 thread_add_read(master, bfd_recv_cb, NULL, bglobal.bg_shop6,
 435                                 &bglobal.bg_ev[2]);
 436         } else if (sd == bglobal.bg_mhop6) {
 437                 THREAD_OFF(bglobal.bg_ev[3]);
 438                 thread_add_read(master, bfd_recv_cb, NULL, bglobal.bg_mhop6,
 439                                 &bglobal.bg_ev[3]);
 440         } else if (sd == bglobal.bg_echo) {
 441                 THREAD_OFF(bglobal.bg_ev[4]);
 442                 thread_add_read(master, bfd_recv_cb, NULL, bglobal.bg_echo,
 443                                 &bglobal.bg_ev[4]);
 444         } else if (sd == bglobal.bg_echov6) {
 445                 THREAD_OFF(bglobal.bg_ev[5]);
 446                 thread_add_read(master, bfd_recv_cb, NULL, bglobal.bg_echov6,
 447                                 &bglobal.bg_ev[5]);
 448         }
 449 }
 450
 451 static void cp_debug(bool mhop, struct sockaddr_any *peer,
 452                      struct sockaddr_any *local, const char *port,
 453                      const char *vrf, const char *fmt, ...)
 454 {
 455         char buf[512], peerstr[128], localstr[128], portstr[64], vrfstr[64];
 456         va_list vl;
 457
 458         if (peer->sa_sin.sin_family)
 459                 snprintf(peerstr, sizeof(peerstr), " peer:%s", satostr(peer));
 460         else
 461                 peerstr[0] = 0;
 462
 463         if (local->sa_sin.sin_family)
 464                 snprintf(localstr, sizeof(localstr), " local:%s",
 465                          satostr(local));
 466         else
 467                 localstr[0] = 0;
 468
 469         if (port[0])
 470                 snprintf(portstr, sizeof(portstr), " port:%s", port);
 471         else
 472                 portstr[0] = 0;
 473
 474         if (vrf[0])
 475                 snprintf(vrfstr, sizeof(vrfstr), " vrf:%s", port);
 476         else
 477                 vrfstr[0] = 0;
 478
 479         va_start(vl, fmt);
 480         vsnprintf(buf, sizeof(buf), fmt, vl);
 481         va_end(vl);
 482
 483         log_debug("control-packet: %s [mhop:%s%s%s%s%s]", buf,
 484                   mhop ? "yes" : "no", peerstr, localstr, portstr, vrfstr);
 485 }
 486
 487 int bfd_recv_cb(struct thread *t)
 488 {
 489         int sd = THREAD_FD(t);
 490         struct bfd_session *bfd;
 491         struct bfd_pkt *cp;
 492         bool is_mhop;
 493         ssize_t mlen = 0;
 494         uint32_t oldEchoXmt_TO, oldXmtTime;
 495         uint8_t ttl;
 496         struct sockaddr_any local, peer;
 497         char port[MAXNAMELEN + 1], vrfname[MAXNAMELEN + 1];
 498         uint8_t msgbuf[1516];
 499
 500         /* Schedule next read. */
 501         bfd_sd_reschedule(sd);
 502
 503         /* Handle echo packets. */
 504         if (sd == bglobal.bg_echo || sd == bglobal.bg_echov6) {
 505                 ptm_bfd_process_echo_pkt(sd);
 506                 return 0;
 507         }
 508
 509         /* Sanitize input/output. */
 510         memset(port, 0, sizeof(port));
 511         memset(vrfname, 0, sizeof(vrfname));
 512         memset(&local, 0, sizeof(local));
 513         memset(&peer, 0, sizeof(peer));
 514
 515         /* Handle control packets. */
 516         is_mhop = false;
 517         if (sd == bglobal.bg_shop || sd == bglobal.bg_mhop) {
 518                 is_mhop = sd == bglobal.bg_mhop;
 519                 mlen = bfd_recv_ipv4(sd, msgbuf, sizeof(msgbuf), &ttl, port,
 520                                      sizeof(port), vrfname, sizeof(vrfname),
 521                                      &local, &peer);
 522         } else if (sd == bglobal.bg_shop6 || sd == bglobal.bg_mhop6) {
 523                 is_mhop = sd == bglobal.bg_mhop6;
 524                 mlen = bfd_recv_ipv6(sd, msgbuf, sizeof(msgbuf), &ttl, port,
 525                                      sizeof(port), vrfname, sizeof(vrfname),
 526                                      &local, &peer);
 527         }
 528
 529         /* Implement RFC 5880 6.8.6 */
 530         if (mlen < BFD_PKT_LEN) {
 531                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 532                          "too small (%ld bytes)", mlen);
 533                 return 0;
 534         }
 535
 536         /* Validate packet TTL. */
 537         if ((is_mhop == false) && (ttl != BFD_TTL_VAL)) {
 538                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 539                          "invalid TTL: %d expected %d", ttl, BFD_TTL_VAL);
 540                 return 0;
 541         }
 542
 543         /*
 544          * Parse the control header for inconsistencies:
 545          * - Invalid version;
 546          * - Bad multiplier configuration;
 547          * - Short packets;
 548          * - Invalid discriminator;
 549          */
 550         cp = (struct bfd_pkt *)(msgbuf);
 551         if (BFD_GETVER(cp->diag) != BFD_VERSION) {
 552                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 553                          "bad version %d", BFD_GETVER(cp->diag));
 554                 return 0;
 555         }
 556
 557         if (cp->detect_mult == 0) {
 558                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 559                          "detect multiplier set to zero");
 560                 return 0;
 561         }
 562
 563         if ((cp->len < BFD_PKT_LEN) || (cp->len > mlen)) {
 564                 cp_debug(is_mhop, &peer, &local, port, vrfname, "too small");
 565                 return 0;
 566         }
 567
 568         if (cp->discrs.my_discr == 0) {
 569                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 570                          "'my discriminator' is zero");
 571                 return 0;
 572         }
 573
 574         /* Find the session that this packet belongs. */
 575         bfd = ptm_bfd_sess_find(cp, port, &peer, &local, vrfname, is_mhop);
 576         if (bfd == NULL) {
 577                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 578                          "no session found");
 579                 return 0;
 580         }
 581
 582         bfd->stats.rx_ctrl_pkt++;
 583
 584         /*
 585          * Multi hop: validate packet TTL.
 586          * Single hop: set local address that received the packet.
 587          */
 588         if (is_mhop) {
 589                 if ((BFD_TTL_VAL - bfd->mh_ttl) > BFD_TTL_VAL) {
 590                         cp_debug(is_mhop, &peer, &local, port, vrfname,
 591                                  "exceeded max hop count (expected %d, got %d)",
 592                                  bfd->mh_ttl, BFD_TTL_VAL);
 593                         return 0;
 594                 }
 595         } else if (bfd->local_ip.sa_sin.sin_family == AF_UNSPEC) {
 596                 bfd->local_ip = local;
 597         }
 598
 599         /*
 600          * If no interface was detected, save the interface where the
 601          * packet came in.
 602          */
 603         if (bfd->ifindex == 0)
 604                 bfd->ifindex = ptm_bfd_fetch_ifindex(port);
 605
 606         /* Log remote discriminator changes. */
 607         if ((bfd->discrs.remote_discr != 0)
 608             && (bfd->discrs.remote_discr != ntohl(cp->discrs.my_discr)))
 609                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 610                          "remote discriminator mismatch (expected %d, got %d)",
 611                          bfd->discrs.remote_discr, ntohl(cp->discrs.my_discr));
 612
 613         bfd->discrs.remote_discr = ntohl(cp->discrs.my_discr);
 614
 615         /* If received the Final bit, the new values should take effect */
 616         if (bfd->polling && BFD_GETFBIT(cp->flags)) {
 617                 bfd->timers.desired_min_tx = bfd->new_timers.desired_min_tx;
 618                 bfd->timers.required_min_rx = bfd->new_timers.required_min_rx;
 619                 bfd->new_timers.desired_min_tx = 0;
 620                 bfd->new_timers.required_min_rx = 0;
 621                 bfd->polling = 0;
 622         }
 623
 624         if (!bfd->demand_mode) {
 625                 /* Compute detect time */
 626                 bfd->detect_TO = cp->detect_mult
 627                                  * ((bfd->timers.required_min_rx
 628                                      > ntohl(cp->timers.desired_min_tx))
 629                                             ? bfd->timers.required_min_rx
 630                                             : ntohl(cp->timers.desired_min_tx));
 631                 bfd->remote_detect_mult = cp->detect_mult;
 632         } else
 633                 cp_debug(is_mhop, &peer, &local, port, vrfname,
 634                          "unsupported demand mode");
 635
 636         /* Save remote diagnostics before state switch. */
 637         bfd->remote_diag = cp->diag & BFD_DIAGMASK;
 638
 639         /* State switch from section 6.8.6 */
 640         if (BFD_GETSTATE(cp->flags) == PTM_BFD_ADM_DOWN) {
 641                 if (bfd->ses_state != PTM_BFD_DOWN)
 642                         ptm_bfd_ses_dn(bfd, BD_NEIGHBOR_DOWN);
 643         } else {
 644                 switch (bfd->ses_state) {
 645                 case (PTM_BFD_DOWN):
 646                         if (BFD_GETSTATE(cp->flags) == PTM_BFD_INIT)
 647                                 ptm_bfd_ses_up(bfd);
 648                         else if (BFD_GETSTATE(cp->flags) == PTM_BFD_DOWN)
 649                                 bfd->ses_state = PTM_BFD_INIT;
 650                         break;
 651                 case (PTM_BFD_INIT):
 652                         if (BFD_GETSTATE(cp->flags) == PTM_BFD_INIT
 653                             || BFD_GETSTATE(cp->flags) == PTM_BFD_UP)
 654                                 ptm_bfd_ses_up(bfd);
 655                         break;
 656                 case (PTM_BFD_UP):
 657                         if (BFD_GETSTATE(cp->flags) == PTM_BFD_DOWN)
 658                                 ptm_bfd_ses_dn(bfd, BD_NEIGHBOR_DOWN);
 659                         break;
 660                 }
 661         }
 662
 663         /*
 664          * Handle echo packet status:
 665          * - Start echo packets if configured and permitted
 666          *   (required_min_echo > 0);
 667          * - Stop echo packets if not allowed (required_min_echo == 0);
 668          * - Recalculate echo packet interval;
 669          */
 670         if (BFD_CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO)) {
 671                 if (BFD_CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE)) {
 672                         if (!ntohl(cp->timers.required_min_echo)) {
 673                                 ptm_bfd_echo_stop(bfd, 1);
 674                         } else {
 675                                 oldEchoXmt_TO = bfd->echo_xmt_TO;
 676                                 bfd->echo_xmt_TO =
 677                                         bfd->timers.required_min_echo;
 678                                 if (ntohl(cp->timers.required_min_echo)
 679                                     > bfd->echo_xmt_TO)
 680                                         bfd->echo_xmt_TO = ntohl(
 681                                                 cp->timers.required_min_echo);
 682                                 if (oldEchoXmt_TO != bfd->echo_xmt_TO)
 683                                         ptm_bfd_echo_start(bfd);
 684                         }
 685                 } else if (ntohl(cp->timers.required_min_echo)) {
 686                         bfd->echo_xmt_TO = bfd->timers.required_min_echo;
 687                         if (ntohl(cp->timers.required_min_echo)
 688                             > bfd->echo_xmt_TO)
 689                                 bfd->echo_xmt_TO =
 690                                         ntohl(cp->timers.required_min_echo);
 691                         ptm_bfd_echo_start(bfd);
 692                 }
 693         }
 694
 695         if (BFD_CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE)) {
 696                 bfd->echo_xmt_TO = bfd->timers.required_min_echo;
 697                 if (ntohl(cp->timers.required_min_echo) > bfd->echo_xmt_TO)
 698                         bfd->echo_xmt_TO = ntohl(cp->timers.required_min_echo);
 699         }
 700
 701         /* Calculate new transmit time */
 702         oldXmtTime = bfd->xmt_TO;
 703         bfd->xmt_TO =
 704                 (bfd->timers.desired_min_tx > ntohl(cp->timers.required_min_rx))
 705                         ? bfd->timers.desired_min_tx
 706                         : ntohl(cp->timers.required_min_rx);
 707
 708         /* If transmit time has changed, and too much time until next xmt,
 709          * restart
 710          */
 711         if (BFD_GETPBIT(cp->flags)) {
 712                 ptm_bfd_xmt_TO(bfd, 1);
 713         } else if (oldXmtTime != bfd->xmt_TO) {
 714                 /* XXX add some skid to this as well */
 715                 ptm_bfd_start_xmt_timer(bfd, false);
 716         }
 717
 718         /* Restart detection timer (packet received) */
 719         if (!bfd->demand_mode)
 720                 bfd_recvtimer_update(bfd);
 721
 722         /*
 723          * Save the timers and state sent by the remote end
 724          * for debugging and statistics.
 725          */
 726         if (BFD_GETFBIT(cp->flags)) {
 727                 bfd->remote_timers.desired_min_tx =
 728                         ntohl(cp->timers.desired_min_tx);
 729                 bfd->remote_timers.required_min_rx =
 730                         ntohl(cp->timers.required_min_rx);
 731                 bfd->remote_timers.required_min_echo =
 732                         ntohl(cp->timers.required_min_echo);
 733
 734                 control_notify_config(BCM_NOTIFY_CONFIG_UPDATE, bfd);
 735         }
 736
 737         return 0;
 738 }
 739
 740 /*
 741  * bp_bfd_echo_in: proccesses an BFD echo packet. On TTL == BFD_TTL_VAL
 742  * the packet is looped back or returns the my discriminator ID along
 743  * with the TTL.
 744  *
 745  * Returns -1 on error or loopback or 0 on success.
 746  */
 747 int bp_bfd_echo_in(int sd, uint8_t *ttl, uint32_t *my_discr)
 748 {
 749         struct bfd_echo_pkt *bep;
 750         ssize_t rlen;
 751         struct sockaddr_any local, peer;
 752         char port[MAXNAMELEN + 1], vrfname[MAXNAMELEN + 1];
 753         uint8_t msgbuf[1516];
 754
 755         if (sd == bglobal.bg_echo)
 756                 rlen = bfd_recv_ipv4(sd, msgbuf, sizeof(msgbuf), ttl, port,
 757                                      sizeof(port), vrfname, sizeof(vrfname),
 758                                      &local, &peer);
 759         else
 760                 rlen = bfd_recv_ipv6(sd, msgbuf, sizeof(msgbuf), ttl, port,
 761                                      sizeof(port), vrfname, sizeof(vrfname),
 762                                      &local, &peer);
 763
 764         /* Short packet, better not risk reading it. */
 765         if (rlen < (ssize_t)sizeof(*bep)) {
 766                 cp_debug(false, &peer, &local, port, vrfname,
 767                          "small echo packet");
 768                 return -1;
 769         }
 770
 771         /* Test for loopback. */
 772         if (*ttl == BFD_TTL_VAL) {
 773                 bp_udp_send(sd, *ttl - 1, msgbuf, rlen,
 774                             (struct sockaddr *)&peer,
 775                             (sd == bglobal.bg_echo) ? sizeof(peer.sa_sin)
 776                                                     : sizeof(peer.sa_sin6));
 777                 return -1;
 778         }
 779
 780         /* Read my discriminator from BFD Echo packet. */
 781         bep = (struct bfd_echo_pkt *)msgbuf;
 782         *my_discr = ntohl(bep->my_discr);
 783         if (*my_discr == 0) {
 784                 cp_debug(false, &peer, &local, port, vrfname,
 785                          "invalid echo packet discriminator (zero)");
 786                 return -1;
 787         }
 788
 789         return 0;
 790 }
 791
 792 int bp_udp_send(int sd, uint8_t ttl, uint8_t *data, size_t datalen,
 793                 struct sockaddr *to, socklen_t tolen)
 794 {
 795         struct cmsghdr *cmsg;
 796         ssize_t wlen;
 797         int ttlval = ttl;
 798         bool is_ipv6 = to->sa_family == AF_INET6;
 799         struct msghdr msg;
 800         struct iovec iov[1];
 801         uint8_t msgctl[255];
 802
 803         /* Prepare message data. */
 804         iov[0].iov_base = data;
 805         iov[0].iov_len = datalen;
 806
 807         memset(&msg, 0, sizeof(msg));
 808         memset(msgctl, 0, sizeof(msgctl));
 809         msg.msg_name = to;
 810         msg.msg_namelen = tolen;
 811         msg.msg_iov = iov;
 812         msg.msg_iovlen = 1;
 813
 814         /* Prepare the packet TTL information. */
 815         if (ttl > 0) {
 816                 /* Use ancillary data. */
 817                 msg.msg_control = msgctl;
 818                 msg.msg_controllen = CMSG_LEN(sizeof(ttlval));
 819
 820                 /* Configure the ancillary data. */
 821                 cmsg = CMSG_FIRSTHDR(&msg);
 822                 cmsg->cmsg_len = CMSG_LEN(sizeof(ttlval));
 823                 if (is_ipv6) {
 824                         cmsg->cmsg_level = IPPROTO_IPV6;
 825                         cmsg->cmsg_type = IPV6_HOPLIMIT;
 826                 } else {
 827 #if BFD_LINUX
 828                         cmsg->cmsg_level = IPPROTO_IP;
 829                         cmsg->cmsg_type = IP_TTL;
 830 #else
 831                         /* FreeBSD does not support TTL in ancillary data. */
 832                         msg.msg_control = NULL;
 833                         msg.msg_controllen = 0;
 834
 835                         bp_set_ttl(sd, ttl);
 836 #endif /* BFD_BSD */
 837                 }
 838                 memcpy(CMSG_DATA(cmsg), &ttlval, sizeof(ttlval));
 839         }
 840
 841         /* Send echo back. */
 842         wlen = sendmsg(sd, &msg, 0);
 843         if (wlen <= 0) {
 844                 log_debug("udp-send: loopback failure: (%d) %s", errno, strerror(errno));
 845                 return -1;
 846         } else if (wlen < (ssize_t)datalen) {
 847                 log_debug("udp-send: partial send: %ld expected %ld", wlen,
 848                           datalen);
 849                 return -1;
 850         }
 851
 852         return 0;
 853 }
 854
 855
 856 /*
 857  * Sockets creation.
 858  */
 859
 860
 861 /*
 862  * IPv4 sockets
 863  */
 864 int bp_set_ttl(int sd, uint8_t value)
 865 {
 866         int ttl = value;
 867
 868         if (setsockopt(sd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) == -1) {
 869                 log_warning("set-ttl: setsockopt(IP_TTL, %d): %s", value,
 870                             strerror(errno));
 871                 return -1;
 872         }
 873
 874         return 0;
 875 }
 876
 877 int bp_set_tos(int sd, uint8_t value)
 878 {
 879         int tos = value;
 880
 881         if (setsockopt(sd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) == -1) {
 882                 log_warning("set-tos: setsockopt(IP_TOS, %d): %s", value,
 883                             strerror(errno));
 884                 return -1;
 885         }
 886
 887         return 0;
 888 }
 889
 890 static void bp_set_ipopts(int sd)
 891 {
 892         int rcvttl = BFD_RCV_TTL_VAL;
 893
 894         if (bp_set_ttl(sd, BFD_TTL_VAL) != 0)
 895                 log_fatal("set-ipopts: TTL configuration failed");
 896
 897         if (setsockopt(sd, IPPROTO_IP, IP_RECVTTL, &rcvttl, sizeof(rcvttl))
 898             == -1)
 899                 log_fatal("set-ipopts: setsockopt(IP_RECVTTL, %d): %s", rcvttl,
 900                           strerror(errno));
 901
 902 #ifdef BFD_LINUX
 903         int pktinfo = BFD_PKT_INFO_VAL;
 904
 905         /* Figure out address and interface to do the peer matching. */
 906         if (setsockopt(sd, IPPROTO_IP, IP_PKTINFO, &pktinfo, sizeof(pktinfo))
 907             == -1)
 908                 log_fatal("set-ipopts: setsockopt(IP_PKTINFO, %d): %s", pktinfo,
 909                           strerror(errno));
 910 #endif /* BFD_LINUX */
 911 #ifdef BFD_BSD
 912         int yes = 1;
 913
 914         /* Find out our address for peer matching. */
 915         if (setsockopt(sd, IPPROTO_IP, IP_RECVDSTADDR, &yes, sizeof(yes)) == -1)
 916                 log_fatal("set-ipopts: setsockopt(IP_RECVDSTADDR, %d): %s", yes,
 917                           strerror(errno));
 918
 919         /* Find out interface where the packet came in. */
 920         if (setsockopt_ifindex(AF_INET, sd, yes) == -1)
 921                 log_fatal("set-ipopts: setsockopt_ipv4_ifindex(%d): %s", yes,
 922                           strerror(errno));
 923 #endif /* BFD_BSD */
 924 }
 925
 926 static void bp_bind_ip(int sd, uint16_t port)
 927 {
 928         struct sockaddr_in sin;
 929
 930         memset(&sin, 0, sizeof(sin));
 931         sin.sin_family = AF_INET;
 932         sin.sin_addr.s_addr = htonl(INADDR_ANY);
 933         sin.sin_port = htons(port);
 934         if (bind(sd, (struct sockaddr *)&sin, sizeof(sin)) == -1)
 935                 log_fatal("bind-ip: bind: %s", strerror(errno));
 936 }
 937
 938 int bp_udp_shop(void)
 939 {
 940         int sd;
 941
 942         sd = socket(AF_INET, SOCK_DGRAM, PF_UNSPEC);
 943         if (sd == -1)
 944                 log_fatal("udp-shop: socket: %s", strerror(errno));
 945
 946         bp_set_ipopts(sd);
 947         bp_bind_ip(sd, BFD_DEFDESTPORT);
 948
 949         return sd;
 950 }
 951
 952 int bp_udp_mhop(void)
 953 {
 954         int sd;
 955
 956         sd = socket(AF_INET, SOCK_DGRAM, PF_UNSPEC);
 957         if (sd == -1)
 958                 log_fatal("udp-mhop: socket: %s", strerror(errno));
 959
 960         bp_set_ipopts(sd);
 961         bp_bind_ip(sd, BFD_DEF_MHOP_DEST_PORT);
 962
 963         return sd;
 964 }
 965
 966 int bp_peer_socket(struct bfd_peer_cfg *bpc)
 967 {
 968         int sd, pcount;
 969         struct sockaddr_in sin;
 970         static int srcPort = BFD_SRCPORTINIT;
 971
 972         sd = socket(AF_INET, SOCK_DGRAM, PF_UNSPEC);
 973         if (sd == -1) {
 974                 log_error("ipv4-new: failed to create socket: %s",
 975                           strerror(errno));
 976                 return -1;
 977         }
 978
 979         /* Set TTL to 255 for all transmitted packets */
 980         if (bp_set_ttl(sd, BFD_TTL_VAL) != 0) {
 981                 close(sd);
 982                 return -1;
 983         }
 984
 985         /* Set TOS to CS6 for all transmitted packets */
 986         if (bp_set_tos(sd, BFD_TOS_VAL) != 0) {
 987                 close(sd);
 988                 return -1;
 989         }
 990
 991         if (bpc->bpc_has_localif) {
 992                 if (bp_bind_dev(sd, bpc->bpc_localif) != 0) {
 993                         close(sd);
 994                         return -1;
 995                 }
 996         } else if (bpc->bpc_mhop && bpc->bpc_has_vrfname) {
 997                 if (bp_bind_dev(sd, bpc->bpc_vrfname) != 0) {
 998                         close(sd);
 999                         return -1;
1000                 }
1001         }
1002
1003         /* Find an available source port in the proper range */
1004         memset(&sin, 0, sizeof(sin));
1005         sin = bpc->bpc_local.sa_sin;
1006         sin.sin_family = AF_INET;
1007 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
1008         sin.sin_len = sizeof(sin);
1009 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
1010         if (bpc->bpc_mhop)
1011                 sin.sin_addr = bpc->bpc_local.sa_sin.sin_addr;
1012         else
1013                 sin.sin_addr.s_addr = INADDR_ANY;
1014
1015         pcount = 0;
1016         do {
1017                 if ((++pcount) > (BFD_SRCPORTMAX - BFD_SRCPORTINIT)) {
1018                         /* Searched all ports, none available */
1019                         log_error("ipv4-new: failed to bind port: %s",
1020                                   strerror(errno));
1021                         close(sd);
1022                         return -1;
1023                 }
1024                 if (srcPort >= BFD_SRCPORTMAX)
1025                         srcPort = BFD_SRCPORTINIT;
1026                 sin.sin_port = htons(srcPort++);
1027         } while (bind(sd, (struct sockaddr *)&sin, sizeof(sin)) < 0);
1028
1029         return sd;
1030 }
1031
1032
1033 /*
1034  * IPv6 sockets
1035  */
1036
1037 int bp_peer_socketv6(struct bfd_peer_cfg *bpc)
1038 {
1039         int sd, pcount, ifindex;
1040         struct sockaddr_in6 sin6;
1041         static int srcPort = BFD_SRCPORTINIT;
1042
1043         sd = socket(AF_INET6, SOCK_DGRAM, PF_UNSPEC);
1044         if (sd == -1) {
1045                 log_error("ipv6-new: failed to create socket: %s",
1046                           strerror(errno));
1047                 return -1;
1048         }
1049
1050         /* Set TTL to 255 for all transmitted packets */
1051         if (bp_set_ttlv6(sd, BFD_TTL_VAL) != 0) {
1052                 close(sd);
1053                 return -1;
1054         }
1055
1056         /* Set TOS to CS6 for all transmitted packets */
1057         if (bp_set_tosv6(sd, BFD_TOS_VAL) != 0) {
1058                 close(sd);
1059                 return -1;
1060         }
1061
1062         /* Find an available source port in the proper range */
1063         memset(&sin6, 0, sizeof(sin6));
1064         sin6.sin6_family = AF_INET6;
1065 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
1066         sin6.sin6_len = sizeof(sin6);
1067 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
1068         sin6 = bpc->bpc_local.sa_sin6;
1069         ifindex = ptm_bfd_fetch_ifindex(bpc->bpc_localif);
1070         if (IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr))
1071                 sin6.sin6_scope_id = ifindex;
1072
1073         if (bpc->bpc_has_localif) {
1074                 if (bp_bind_dev(sd, bpc->bpc_localif) != 0) {
1075                         close(sd);
1076                         return -1;
1077                 }
1078         } else if (bpc->bpc_mhop && bpc->bpc_has_vrfname) {
1079                 if (bp_bind_dev(sd, bpc->bpc_vrfname) != 0) {
1080                         close(sd);
1081                         return -1;
1082                 }
1083         }
1084
1085         pcount = 0;
1086         do {
1087                 if ((++pcount) > (BFD_SRCPORTMAX - BFD_SRCPORTINIT)) {
1088                         /* Searched all ports, none available */
1089                         log_error("ipv6-new: failed to bind port: %s",
1090                                   strerror(errno));
1091                         close(sd);
1092                         return -1;
1093                 }
1094                 if (srcPort >= BFD_SRCPORTMAX)
1095                         srcPort = BFD_SRCPORTINIT;
1096                 sin6.sin6_port = htons(srcPort++);
1097         } while (bind(sd, (struct sockaddr *)&sin6, sizeof(sin6)) < 0);
1098
1099         return sd;
1100 }
1101
1102 int bp_set_ttlv6(int sd, uint8_t value)
1103 {
1104         int ttl = value;
1105
1106         if (setsockopt(sd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))
1107             == -1) {
1108                 log_warning("set-ttlv6: setsockopt(IPV6_UNICAST_HOPS, %d): %s",
1109                             value, strerror(errno));
1110                 return -1;
1111         }
1112
1113         return 0;
1114 }
1115
1116 int bp_set_tosv6(int sd, uint8_t value)
1117 {
1118         int tos = value;
1119
1120         if (setsockopt(sd, IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos))
1121             == -1) {
1122                 log_warning("set-tosv6: setsockopt(IPV6_TCLASS, %d): %s", value,
1123                             strerror(errno));
1124                 return -1;
1125         }
1126
1127         return 0;
1128 }
1129
1130 static void bp_set_ipv6opts(int sd)
1131 {
1132         int ipv6_pktinfo = BFD_IPV6_PKT_INFO_VAL;
1133         int ipv6_only = BFD_IPV6_ONLY_VAL;
1134
1135         if (bp_set_ttlv6(sd, BFD_TTL_VAL) == -1)
1136                 log_fatal("set-ipv6opts: setsockopt(IPV6_UNICAST_HOPS, %d): %s",
1137                           BFD_TTL_VAL, strerror(errno));
1138
1139         if (setsockopt_ipv6_hoplimit(sd, BFD_RCV_TTL_VAL) == -1)
1140                 log_fatal("set-ipv6opts: setsockopt(IPV6_HOPLIMIT, %d): %s",
1141                           BFD_RCV_TTL_VAL, strerror(errno));
1142
1143         if (setsockopt_ipv6_pktinfo(sd, ipv6_pktinfo) == -1)
1144                 log_fatal("set-ipv6opts: setsockopt(IPV6_PKTINFO, %d): %s",
1145                           ipv6_pktinfo, strerror(errno));
1146
1147         if (setsockopt(sd, IPPROTO_IPV6, IPV6_V6ONLY, &ipv6_only,
1148                        sizeof(ipv6_only))
1149             == -1)
1150                 log_fatal("set-ipv6opts: setsockopt(IPV6_V6ONLY, %d): %s",
1151                           ipv6_only, strerror(errno));
1152 }
1153
1154 static void bp_bind_ipv6(int sd, uint16_t port)
1155 {
1156         struct sockaddr_in6 sin6;
1157
1158         memset(&sin6, 0, sizeof(sin6));
1159         sin6.sin6_family = AF_INET6;
1160         sin6.sin6_addr = in6addr_any;
1161         sin6.sin6_port = htons(port);
1162 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
1163         sin6.sin6_len = sizeof(sin6);
1164 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
1165         if (bind(sd, (struct sockaddr *)&sin6, sizeof(sin6)) == -1)
1166                 log_fatal("bind-ipv6: bind: %s", strerror(errno));
1167 }
1168
1169 int bp_udp6_shop(void)
1170 {
1171         int sd;
1172
1173         sd = socket(AF_INET6, SOCK_DGRAM, PF_UNSPEC);
1174         if (sd == -1)
1175                 log_fatal("udp6-shop: socket: %s", strerror(errno));
1176
1177         bp_set_ipv6opts(sd);
1178         bp_bind_ipv6(sd, BFD_DEFDESTPORT);
1179
1180         return sd;
1181 }
1182
1183 int bp_udp6_mhop(void)
1184 {
1185         int sd;
1186
1187         sd = socket(AF_INET6, SOCK_DGRAM, PF_UNSPEC);
1188         if (sd == -1)
1189                 log_fatal("udp6-mhop: socket: %s", strerror(errno));
1190
1191         bp_set_ipv6opts(sd);
1192         bp_bind_ipv6(sd, BFD_DEF_MHOP_DEST_PORT);
1193
1194         return sd;
1195 }
1196
1197 int bp_echo_socket(void)
1198 {
1199         int s;
1200
1201         s = socket(AF_INET, SOCK_DGRAM, 0);
1202         if (s == -1)
1203                 log_fatal("echo-socket: socket: %s", strerror(errno));
1204
1205         bp_set_ipopts(s);
1206         bp_bind_ip(s, BFD_DEF_ECHO_PORT);
1207
1208         return s;
1209 }
1210
1211 int bp_echov6_socket(void)
1212 {
1213         int s;
1214
1215         s = socket(AF_INET6, SOCK_DGRAM, 0);
1216         if (s == -1)
1217                 log_fatal("echov6-socket: socket: %s", strerror(errno));
1218
1219         bp_set_ipv6opts(s);
1220         bp_bind_ipv6(s, BFD_DEF_ECHO_PORT);
1221
1222         return s;
1223 }