proto/ospf/packet.c

   1 /*
   2  *      BIRD -- OSPF
   3  *
   4  *      (c) 1999--2005 Ondrej Filip <feela@network.cz>
   5  *      (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
   6  *      (c) 2009--2014 CZ.NIC z.s.p.o.
   7  *
   8  *      Can be freely distributed and used under the terms of the GNU GPL.
   9  */
  10
  11 #include "ospf.h"
  12 #include "nest/password.h"
  13 #include "lib/md5.h"
  14 #include "lib/mac.h"
  15 #include "lib/socket.h"
  16
  17 void
  18 ospf_pkt_fill_hdr(struct ospf_iface *ifa, void *buf, u8 h_type)
  19 {
  20   struct ospf_proto *p = ifa->oa->po;
  21   struct ospf_packet *pkt;
  22
  23   pkt = (struct ospf_packet *) buf;
  24
  25   pkt->version = ospf_get_version(p);
  26   pkt->type = h_type;
  27   pkt->length = htons(ospf_pkt_maxsize(ifa));
  28   pkt->routerid = htonl(p->router_id);
  29   pkt->areaid = htonl(ifa->oa->areaid);
  30   pkt->checksum = 0;
  31   pkt->instance_id = ifa->instance_id;
  32   pkt->autype = ospf_is_v2(p) ? ifa->autype : 0;
  33 }
  34
  35 /* We assume OSPFv2 in ospf_pkt_finalize() */
  36 static void
  37 ospf_pkt_finalize2(struct ospf_iface *ifa, struct ospf_packet *pkt, uint *plen)
  38 {
  39   struct ospf_proto *p = ifa->oa->po;
  40   struct password_item *pass = NULL;
  41   union ospf_auth2 *auth = (void *) (pkt + 1);
  42   memset(auth, 0, sizeof(union ospf_auth2));
  43
  44   /* Compatibility note: auth may contain anything if autype is
  45      none, but nonzero values do not work with Mikrotik OSPF */
  46
  47   pkt->checksum = 0;
  48   pkt->autype = ifa->autype;
  49
  50   switch (ifa->autype)
  51   {
  52   case OSPF_AUTH_SIMPLE:
  53     pass = password_find(ifa->passwords, 1);
  54     if (!pass)
  55     {
  56       log(L_ERR "No suitable password found for authentication");
  57       return;
  58     }
  59     strncpy(auth->password, pass->password, sizeof(auth->password));
  60     /* fallthrough */
  61
  62   case OSPF_AUTH_NONE:
  63     {
  64       void *body = (void *) (auth + 1);
  65       uint blen = *plen - sizeof(struct ospf_packet) - sizeof(union ospf_auth2);
  66       pkt->checksum = ipsum_calculate(pkt, sizeof(struct ospf_packet), body, blen, NULL);
  67     }
  68     break;
  69
  70   case OSPF_AUTH_CRYPT:
  71     pass = password_find(ifa->passwords, 0);
  72     if (!pass)
  73     {
  74       log(L_ERR "%s: No suitable password found for authentication", p->p.name);
  75       return;
  76     }
  77
  78     /* Perhaps use random value to prevent replay attacks after
  79        reboot when system does not have independent RTC? */
  80     if (!ifa->csn)
  81     {
  82       ifa->csn = (u32) (current_real_time() TO_S);
  83       ifa->csn_use = current_time();
  84     }
  85
  86     /* We must have sufficient delay between sending a packet and increasing
  87        CSN to prevent reordering of packets (in a network) with different CSNs */
  88     if ((current_time() - ifa->csn_use) > 1 S)
  89       ifa->csn++;
  90
  91     ifa->csn_use = current_time();
  92
  93     uint auth_len = mac_type_length(pass->alg);
  94     byte *auth_tail = ((byte *) pkt + *plen);
  95     *plen += auth_len;
  96
  97     ASSERT(*plen < ifa->sk->tbsize);
  98
  99     auth->c32.zero = 0;
 100     auth->c32.keyid = pass->id;
 101     auth->c32.len = auth_len;
 102     auth->c32.csn = htonl(ifa->csn);
 103
 104     /* Append key for keyed hash, append padding for HMAC (RFC 5709 3.3) */
 105     if (pass->alg < ALG_HMAC)
 106       strncpy(auth_tail, pass->password, auth_len);
 107     else
 108       memset32(auth_tail, HMAC_MAGIC, auth_len / 4);
 109
 110     mac_fill(pass->alg, pass->password, pass->length, (byte *) pkt, *plen, auth_tail);
 111     break;
 112
 113   default:
 114     bug("Unknown authentication type");
 115   }
 116 }
 117
 118 /*
 119  * Return an extra packet size that should be added to a final packet size
 120  */
 121 static void
 122 ospf_pkt_finalize3(struct ospf_iface *ifa, struct ospf_packet *pkt, uint *plen, ip_addr src)
 123 {
 124   struct ospf_proto *p = ifa->oa->po;
 125   struct ospf_auth3 *auth = (void *) ((byte *) pkt + *plen);
 126
 127   pkt->checksum = 0;
 128   pkt->autype = 0;
 129
 130   if (ifa->autype != OSPF_AUTH_CRYPT)
 131     return;
 132
 133   struct password_item *pass = password_find(ifa->passwords, 0);
 134   if (!pass)
 135   {
 136     log(L_ERR "%s: No suitable password found for authentication", p->p.name);
 137     return;
 138   }
 139
 140   /* FIXME: Ensure persistence */
 141   p->csn64++;
 142
 143   uint mac_len = mac_type_length(pass->alg);
 144   uint auth_len = sizeof(struct ospf_auth3) + mac_len;
 145   *plen += auth_len;
 146
 147   ASSERT(*plen < ifa->sk->tbsize);
 148
 149   memset(auth, 0, sizeof(struct ospf_auth3));
 150   auth->type = htons(OSPF3_AUTH_HMAC);
 151   auth->length = htons(auth_len);
 152   auth->reserved = 0;
 153   auth->sa_id = htons(pass->id);
 154   put_u64(&auth->csn, p->csn64);
 155
 156   /* Initialize with src IP address padded with HMAC_MAGIC */
 157   put_ip6(auth->data, ipa_to_ip6(src));
 158   memset32(auth->data + 16, HMAC_MAGIC, (mac_len - 16) / 4);
 159
 160   /* Attach OSPFv3 Cryptographic Protocol ID to the key */
 161   uint pass_len = pass->length + 2;
 162   byte *pass_key = alloca(pass_len);
 163   memcpy(pass_key, pass->password, pass->length);
 164   put_u16(pass_key + pass->length, OSPF3_CRYPTO_ID);
 165
 166   mac_fill(pass->alg, pass_key, pass_len, (byte *) pkt, *plen, auth->data);
 167 }
 168
 169
 170 static int
 171 ospf_pkt_checkauth2(struct ospf_neighbor *n, struct ospf_iface *ifa, struct ospf_packet *pkt, uint len)
 172 {
 173   struct ospf_proto *p = ifa->oa->po;
 174   union ospf_auth2 *auth = (void *) (pkt + 1);
 175   struct password_item *pass = NULL;
 176   const char *err_dsc = NULL;
 177   uint err_val = 0;
 178
 179   uint plen = ntohs(pkt->length);
 180   u8 autype = pkt->autype;
 181
 182   if (autype != ifa->autype)
 183     DROP("authentication method mismatch", autype);
 184
 185   switch (autype)
 186   {
 187   case OSPF_AUTH_NONE:
 188     return 1;
 189
 190   case OSPF_AUTH_SIMPLE:
 191     pass = password_find(ifa->passwords, 1);
 192     if (!pass)
 193       DROP1("no password found");
 194
 195     if (!password_verify(pass, auth->password, sizeof(auth->password)))
 196       DROP("wrong password", pass->id);
 197
 198     return 1;
 199
 200   case OSPF_AUTH_CRYPT:
 201     pass = password_find_by_id(ifa->passwords, auth->c32.keyid);
 202     if (!pass)
 203       DROP("no suitable password found", auth->c32.keyid);
 204
 205     uint auth_len = mac_type_length(pass->alg);
 206
 207     if (plen + auth->c32.len > len)
 208       DROP("packet length mismatch", len);
 209
 210     if (auth->c32.len != auth_len)
 211       DROP("wrong authentication length", auth->c32.len);
 212
 213     u32 rcv_csn = ntohl(auth->c32.csn);
 214     if (n && (rcv_csn < n->csn))
 215       // DROP("lower sequence number", rcv_csn);
 216     {
 217       /* We want to report both new and old CSN */
 218       LOG_PKT_AUTH("Authentication failed for nbr %R on %s - "
 219                    "lower sequence number (rcv %u, old %u)",
 220                    n->rid, ifa->ifname, rcv_csn, n->csn);
 221       return 0;
 222     }
 223
 224     byte *auth_tail = ((byte *) pkt) + plen;
 225     byte *auth_data = alloca(auth_len);
 226     memcpy(auth_data, auth_tail, auth_len);
 227
 228     /* Append key for keyed hash, append padding for HMAC (RFC 5709 3.3) */
 229     if (pass->alg < ALG_HMAC)
 230       strncpy(auth_tail, pass->password, auth_len);
 231     else
 232       memset32(auth_tail, HMAC_MAGIC, auth_len / 4);
 233
 234     if (!mac_verify(pass->alg, pass->password, pass->length,
 235                     (byte *) pkt, plen + auth_len, auth_data))
 236       DROP("wrong authentication code", pass->id);
 237
 238     if (n)
 239       n->csn = rcv_csn;
 240
 241     return 1;
 242
 243   default:
 244     bug("Unknown authentication type");
 245   }
 246
 247 drop:
 248   LOG_PKT_AUTH("Authentication failed for nbr %R on %s - %s (%u)",
 249                (n ? n->rid : ntohl(pkt->routerid)), ifa->ifname, err_dsc, err_val);
 250
 251   return 0;
 252 }
 253
 254 static int
 255 ospf_pkt_checkauth3(struct ospf_neighbor *n, struct ospf_iface *ifa, struct ospf_packet *pkt, uint len, ip_addr src)
 256 {
 257   struct ospf_proto *p = ifa->oa->po;
 258   const char *err_dsc = NULL;
 259   uint err_val = 0;
 260
 261   uint plen = ntohs(pkt->length);
 262   uint opts, lls_present, auth_present;
 263
 264   /*
 265    * When autentication is not enabled, ignore the trailer. This is different
 266    * from OSPFv2, but it is necessary in order to support migration modes. Note
 267    * that regular authenticated packets do not have valid checksum and will be
 268    * dropped by OS on non-authenticated ifaces.
 269    */
 270   if (ifa->autype != OSPF_AUTH_CRYPT)
 271     return 1;
 272
 273   switch(pkt->type)
 274   {
 275   case HELLO_P:
 276     opts = ospf_hello3_options(pkt);
 277     lls_present = opts & OPT_L_V3;
 278     auth_present = opts & OPT_AT;
 279     break;
 280
 281   case DBDES_P:
 282     opts = ospf_dbdes3_options(pkt);
 283     lls_present = opts & OPT_L_V3;
 284     auth_present = opts & OPT_AT;
 285     break;
 286
 287   default:
 288     lls_present = 0;
 289     auth_present = n->options & OPT_AT;
 290   }
 291
 292   if (!auth_present)
 293     DROP1("missing authentication trailer");
 294
 295   if (lls_present)
 296   {
 297     if ((plen + sizeof(struct ospf_lls)) > len)
 298       DROP("packet length mismatch", len);
 299
 300     struct ospf_lls *lls = (void *) ((byte *) pkt + plen);
 301     plen += ntohs(lls->length);
 302   }
 303
 304   if ((plen + sizeof(struct ospf_auth3)) > len)
 305     DROP("packet length mismatch", len);
 306
 307   struct ospf_auth3 *auth = (void *) ((byte *) pkt + plen);
 308
 309   uint rcv_auth_type = ntohs(auth->type);
 310   if (rcv_auth_type != OSPF3_AUTH_HMAC)
 311     DROP("authentication method mismatch", rcv_auth_type);
 312
 313   uint rcv_auth_len = ntohs(auth->length);
 314   if (plen + rcv_auth_len > len)
 315     DROP("packet length mismatch", len);
 316
 317   uint rcv_key_id = ntohs(auth->sa_id);
 318   struct password_item *pass = password_find_by_id(ifa->passwords, rcv_key_id);
 319   if (!pass)
 320     DROP("no suitable password found", rcv_key_id);
 321
 322   uint mac_len = mac_type_length(pass->alg);
 323   if (rcv_auth_len != (sizeof(struct ospf_auth3) + mac_len))
 324     DROP("wrong authentication length", rcv_auth_len);
 325
 326   uint pt = pkt->type - 1;
 327   u64 rcv_csn = get_u64(&auth->csn);
 328   if (n && (rcv_csn <= n->csn64[pt]))
 329   {
 330     /* We want to report both new and old CSN */
 331     LOG_PKT_AUTH("Authentication failed for nbr %R on %s - "
 332                  "lower sequence number (rcv %u, old %u)",
 333                  n->rid, ifa->ifname, (uint) rcv_csn, (uint) n->csn64[pt]);
 334     return 0;
 335   }
 336
 337   /* Save the received authentication data */
 338   byte *auth_data = alloca(mac_len);
 339   memcpy(auth_data, auth->data, mac_len);
 340
 341   /* Initialize with src IP address padded with HMAC_MAGIC */
 342   put_ip6(auth->data, ipa_to_ip6(src));
 343   memset32(auth->data + 16, HMAC_MAGIC, (mac_len - 16) / 4);
 344
 345   /* Attach OSPFv3 Cryptographic Protocol ID to the key */
 346   uint pass_len = pass->length + 2;
 347   byte *pass_key = alloca(pass_len);
 348   memcpy(pass_key, pass->password, pass->length);
 349   put_u16(pass_key + pass->length, OSPF3_CRYPTO_ID);
 350
 351   if (!mac_verify(pass->alg, pass_key, pass_len,
 352                   (byte *) pkt, plen + rcv_auth_len, auth_data))
 353     DROP("wrong authentication code", pass->id);
 354
 355   if (n)
 356     n->csn64[pt] = rcv_csn;
 357
 358   return 1;
 359
 360 drop:
 361   LOG_PKT_AUTH("Authentication failed for nbr %R on %s - %s (%u)",
 362                (n ? n->rid : ntohl(pkt->routerid)), ifa->ifname, err_dsc, err_val);
 363
 364   return 0;
 365 }
 366
 367 /**
 368  * ospf_rx_hook
 369  * @sk: socket we received the packet.
 370  * @len: length of the packet
 371  *
 372  * This is the entry point for messages from neighbors. Many checks (like
 373  * authentication, checksums, size) are done before the packet is passed to
 374  * non generic functions.
 375  */
 376 int
 377 ospf_rx_hook(sock *sk, uint len)
 378 {
 379   /* We want just packets from sk->iface. Unfortunately, on BSD we cannot filter
 380      out other packets at kernel level and we receive all packets on all sockets */
 381   if (sk->lifindex != sk->iface->index)
 382     return 1;
 383
 384   DBG("OSPF: RX hook called (iface %s, src %I, dst %I)\n",
 385       sk->iface->name, sk->faddr, sk->laddr);
 386
 387   /* Initially, the packet is associated with the 'master' iface */
 388   struct ospf_iface *ifa = sk->data;
 389   struct ospf_proto *p = ifa->oa->po;
 390   const char *err_dsc = NULL;
 391   uint err_val = 0;
 392
 393   /* Should not happen */
 394   if (ifa->state <= OSPF_IS_LOOP)
 395     return 1;
 396
 397   int src_local, dst_local, dst_mcast;
 398   src_local = ipa_in_netX(sk->faddr, &ifa->addr->prefix);
 399   dst_local = ipa_equal(sk->laddr, ifa->addr->ip);
 400   dst_mcast = ipa_equal(sk->laddr, ifa->all_routers) || ipa_equal(sk->laddr, ifa->des_routers);
 401
 402   if (ospf_is_v2(p))
 403   {
 404     /* First, we eliminate packets with strange address combinations.
 405      * In OSPFv2, they might be for other ospf_ifaces (with different IP
 406      * prefix) on the same real iface, so we don't log it. We enforce
 407      * that (src_local || dst_local), therefore we are eliminating all
 408      * such cases.
 409      */
 410     if (dst_mcast && !src_local)
 411       return 1;
 412     if (!dst_mcast && !dst_local)
 413       return 1;
 414
 415     /* Ignore my own broadcast packets */
 416     if (ifa->cf->real_bcast && ipa_equal(sk->faddr, ifa->addr->ip))
 417       return 1;
 418   }
 419   else
 420   {
 421     /* In OSPFv3, src_local and dst_local mean link-local.
 422      * RFC 5340 says that local (non-vlink) packets use
 423      * link-local src address, but does not enforce it. Strange.
 424      */
 425     if (dst_mcast && !src_local)
 426       LOG_PKT_WARN("Multicast packet received from non-link-local %I via %s",
 427                    sk->faddr, ifa->ifname);
 428   }
 429
 430   /* Second, we check packet length, checksum, and the protocol version */
 431   struct ospf_packet *pkt = (void *) sk_rx_buffer(sk, &len);
 432
 433
 434   if (pkt == NULL)
 435     DROP("bad IP header", len);
 436
 437   if (len < sizeof(struct ospf_packet))
 438     DROP("too short", len);
 439
 440   if (pkt->version != ospf_get_version(p))
 441     DROP("version mismatch", pkt->version);
 442
 443   uint plen = ntohs(pkt->length);
 444   if ((plen < sizeof(struct ospf_packet)) || ((plen % 4) != 0))
 445     DROP("invalid length", plen);
 446
 447   if (sk->flags & SKF_TRUNCATED)
 448   {
 449     /* If we have dynamic buffers and received truncated message, we expand RX buffer */
 450
 451     uint bs = plen + 256;
 452     bs = BIRD_ALIGN(bs, 1024);
 453
 454     if (!ifa->cf->rx_buffer && (bs > sk->rbsize))
 455       sk_set_rbsize(sk, bs);
 456
 457     DROP("truncated", plen);
 458   }
 459
 460   if (plen > len)
 461     DROP("length mismatch", plen);
 462
 463   if (ospf_is_v2(p) && (pkt->autype != OSPF_AUTH_CRYPT))
 464   {
 465     uint hlen = sizeof(struct ospf_packet) + sizeof(union ospf_auth2);
 466     uint blen = plen - hlen;
 467     void *body = ((void *) pkt) + hlen;
 468
 469     if (!ipsum_verify(pkt, sizeof(struct ospf_packet), body, blen, NULL))
 470       DROP("invalid checksum", ntohs(pkt->checksum));
 471   }
 472
 473   /* Third, we resolve associated iface and handle vlinks. */
 474
 475   u32 areaid = ntohl(pkt->areaid);
 476   u32 rid = ntohl(pkt->routerid);
 477   u8 instance_id = pkt->instance_id;
 478
 479   if (areaid == ifa->oa->areaid)
 480   {
 481     /* Matching area ID */
 482
 483     if (instance_id != ifa->instance_id)
 484       return 1;
 485
 486     /* It is real iface, source should be local (in OSPFv2) */
 487     if (ospf_is_v2(p) && !src_local)
 488       DROP1("strange source address");
 489
 490     goto found;
 491   }
 492   else if ((areaid == 0) && !dst_mcast)
 493   {
 494     /* Backbone area ID and possible vlink packet */
 495
 496     if ((p->areano == 1) || !oa_is_ext(ifa->oa))
 497       return 1;
 498
 499     struct ospf_iface *iff = NULL;
 500     WALK_LIST(iff, p->iface_list)
 501     {
 502       if ((iff->type == OSPF_IT_VLINK) &&
 503           (iff->voa == ifa->oa) &&
 504           (iff->instance_id == instance_id) &&
 505           (iff->vid == rid))
 506       {
 507         /* Vlink should be UP */
 508         if (iff->state != OSPF_IS_PTP)
 509           return 1;
 510
 511         ifa = iff;
 512         goto found;
 513       }
 514     }
 515
 516     /*
 517      * Cannot find matching vlink. It is either misconfigured vlink; NBMA or
 518      * PtMP with misconfigured area ID, or packet for some other instance (that
 519      * is possible even if instance_id == ifa->instance_id, because it may be
 520      * also vlink packet in the other instance, which is different namespace).
 521      */
 522
 523     return 1;
 524   }
 525   else
 526   {
 527     /* Non-matching area ID but cannot be vlink packet */
 528
 529     if (instance_id != ifa->instance_id)
 530       return 1;
 531
 532     DROP("area mismatch", areaid);
 533   }
 534
 535
 536 found:
 537   if (ifa->stub)            /* This shouldn't happen */
 538     return 1;
 539
 540   if (ipa_equal(sk->laddr, ifa->des_routers) && (ifa->sk_dr == 0))
 541     return 1;
 542
 543   /* TTL check must be done after instance dispatch */
 544   if (ifa->check_ttl && (sk->rcv_ttl < 255))
 545     DROP("wrong TTL", sk->rcv_ttl);
 546
 547   if (rid == p->router_id)
 548     DROP1("my own router ID");
 549
 550   if (rid == 0)
 551     DROP1("zero router ID");
 552
 553   /* In OSPFv2, neighbors are identified by either IP or Router ID, based on network type */
 554   uint t = ifa->type;
 555   struct ospf_neighbor *n;
 556   if (ospf_is_v2(p) && ((t == OSPF_IT_BCAST) || (t == OSPF_IT_NBMA) || (t == OSPF_IT_PTMP)))
 557     n = find_neigh_by_ip(ifa, sk->faddr);
 558   else
 559     n = find_neigh(ifa, rid);
 560
 561   if (!n && (pkt->type != HELLO_P))
 562   {
 563     OSPF_TRACE(D_PACKETS, "Non-HELLO packet received from unknown nbr %R on %s, src %I",
 564                rid, ifa->ifname, sk->faddr);
 565     return 1;
 566   }
 567
 568   /* Check packet type here, ospf_pkt_checkauth3() expects valid values */
 569   if (pkt->type < HELLO_P || pkt->type > LSACK_P)
 570     DROP("invalid packet type", pkt->type);
 571
 572   /* ospf_pkt_checkauth() has its own error logging */
 573   if ((ospf_is_v2(p) ?
 574        !ospf_pkt_checkauth2(n, ifa, pkt, len) :
 575        !ospf_pkt_checkauth3(n, ifa, pkt, len, sk->faddr)))
 576     return 1;
 577
 578   switch (pkt->type)
 579   {
 580   case HELLO_P:
 581     ospf_receive_hello(pkt, ifa, n, sk->faddr);
 582     break;
 583
 584   case DBDES_P:
 585     ospf_receive_dbdes(pkt, ifa, n);
 586     break;
 587
 588   case LSREQ_P:
 589     ospf_receive_lsreq(pkt, ifa, n);
 590     break;
 591
 592   case LSUPD_P:
 593     ospf_receive_lsupd(pkt, ifa, n);
 594     break;
 595
 596   case LSACK_P:
 597     ospf_receive_lsack(pkt, ifa, n);
 598     break;
 599   };
 600   return 1;
 601
 602 drop:
 603   LOG_PKT("Bad packet from %I via %s - %s (%u)",
 604           sk->faddr, ifa->ifname, err_dsc, err_val);
 605
 606   return 1;
 607 }
 608
 609 /*
 610 void
 611 ospf_tx_hook(sock * sk)
 612 {
 613   struct ospf_iface *ifa= (struct ospf_iface *) (sk->data);
 614 //  struct proto *p = (struct proto *) (ifa->oa->p);
 615   log(L_ERR "OSPF: TX hook called on %s", ifa->ifname);
 616 }
 617 */
 618
 619 void
 620 ospf_err_hook(sock * sk, int err)
 621 {
 622   struct ospf_iface *ifa = (struct ospf_iface *) (sk->data);
 623   struct ospf_proto *p = ifa->oa->po;
 624   log(L_ERR "%s: Socket error on %s: %M", p->p.name, ifa->ifname, err);
 625 }
 626
 627 void
 628 ospf_verr_hook(sock *sk, int err)
 629 {
 630   struct ospf_proto *p = (struct ospf_proto *) (sk->data);
 631   log(L_ERR "%s: Vlink socket error: %M", p->p.name, err);
 632 }
 633
 634 void
 635 ospf_send_to(struct ospf_iface *ifa, ip_addr dst)
 636 {
 637   sock *sk = ifa->sk;
 638   struct ospf_packet *pkt = (struct ospf_packet *) sk->tbuf;
 639   uint plen = ntohs(pkt->length);
 640
 641   if (ospf_is_v2(ifa->oa->po))
 642     ospf_pkt_finalize2(ifa, pkt, &plen);
 643   else
 644     ospf_pkt_finalize3(ifa, pkt, &plen, sk->saddr);
 645
 646   int done = sk_send_to(sk, plen, dst, 0);
 647   if (!done)
 648     log(L_WARN "OSPF: TX queue full on %s", ifa->ifname);
 649 }
 650
 651 void
 652 ospf_send_to_agt(struct ospf_iface *ifa, u8 state)
 653 {
 654   struct ospf_neighbor *n;
 655
 656   WALK_LIST(n, ifa->neigh_list)
 657     if (n->state >= state)
 658       ospf_send_to(ifa, n->ip);
 659 }
 660
 661 void
 662 ospf_send_to_bdr(struct ospf_iface *ifa)
 663 {
 664   if (ipa_nonzero2(ifa->drip))
 665     ospf_send_to(ifa, ifa->drip);
 666   if (ipa_nonzero2(ifa->bdrip))
 667     ospf_send_to(ifa, ifa->bdrip);
 668 }