The Tcpdump Group git mirrors - tcpdump/blob - print-bgp.c

   1 /*
   2  * Copyright (C) 1999 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 #ifdef HAVE_CONFIG_H
  31 #include "config.h"
  32 #endif
  33
  34 #ifndef lint
  35 static const char rcsid[] =
  36      "@(#) $Header: /tcpdump/master/tcpdump/print-bgp.c,v 1.28 2002-05-16 10:20:47 guy Exp $";
  37 #endif
  38
  39 #include <sys/param.h>
  40 #include <sys/time.h>
  41 #include <sys/types.h>
  42 #include <sys/socket.h>
  43
  44 #include <netinet/in.h>
  45
  46 #include <errno.h>
  47 #include <stdio.h>
  48 #include <string.h>
  49 #include <netdb.h>
  50
  51 #include "interface.h"
  52 #include "addrtoname.h"
  53 #include "extract.h"
  54
  55 struct bgp {
  56         u_int8_t bgp_marker[16];
  57         u_int16_t bgp_len;
  58         u_int8_t bgp_type;
  59 };
  60 #define BGP_SIZE                19      /* unaligned */
  61
  62 #define BGP_OPEN                1
  63 #define BGP_UPDATE              2
  64 #define BGP_NOTIFICATION        3
  65 #define BGP_KEEPALIVE           4
  66
  67 struct bgp_open {
  68         u_int8_t bgpo_marker[16];
  69         u_int16_t bgpo_len;
  70         u_int8_t bgpo_type;
  71         u_int8_t bgpo_version;
  72         u_int16_t bgpo_myas;
  73         u_int16_t bgpo_holdtime;
  74         u_int32_t bgpo_id;
  75         u_int8_t bgpo_optlen;
  76         /* options should follow */
  77 };
  78 #define BGP_OPEN_SIZE           29      /* unaligned */
  79
  80 struct bgp_opt {
  81         u_int8_t bgpopt_type;
  82         u_int8_t bgpopt_len;
  83         /* variable length */
  84 };
  85 #define BGP_OPT_SIZE            2       /* some compilers may pad to 4 bytes */
  86
  87 struct bgp_notification {
  88         u_int8_t bgpn_marker[16];
  89         u_int16_t bgpn_len;
  90         u_int8_t bgpn_type;
  91         u_int8_t bgpn_major;
  92         u_int8_t bgpn_minor;
  93         /* data should follow */
  94 };
  95 #define BGP_NOTIFICATION_SIZE           21      /* unaligned */
  96
  97 struct bgp_attr {
  98         u_int8_t bgpa_flags;
  99         u_int8_t bgpa_type;
 100         union {
 101                 u_int8_t len;
 102                 u_int16_t elen;
 103         } bgpa_len;
 104 #define bgp_attr_len(p) \
 105         (((p)->bgpa_flags & 0x10) ? \
 106                 ntohs((p)->bgpa_len.elen) : (p)->bgpa_len.len)
 107 #define bgp_attr_off(p) \
 108         (((p)->bgpa_flags & 0x10) ? 4 : 3)
 109 };
 110
 111 #define BGPTYPE_ORIGIN                  1
 112 #define BGPTYPE_AS_PATH                 2
 113 #define BGPTYPE_NEXT_HOP                3
 114 #define BGPTYPE_MULTI_EXIT_DISC         4
 115 #define BGPTYPE_LOCAL_PREF              5
 116 #define BGPTYPE_ATOMIC_AGGREGATE        6
 117 #define BGPTYPE_AGGREGATOR              7
 118 #define BGPTYPE_COMMUNITIES             8       /* RFC1997 */
 119 #define BGPTYPE_ORIGINATOR_ID           9       /* RFC1998 */
 120 #define BGPTYPE_CLUSTER_LIST            10      /* RFC1998 */
 121 #define BGPTYPE_DPA                     11      /* work in progress */
 122 #define BGPTYPE_ADVERTISERS             12      /* RFC1863 */
 123 #define BGPTYPE_RCID_PATH               13      /* RFC1863 */
 124 #define BGPTYPE_MP_REACH_NLRI           14      /* RFC2283 */
 125 #define BGPTYPE_MP_UNREACH_NLRI         15      /* RFC2283 */
 126
 127
 128 static const char *bgptype[] = {
 129         NULL, "OPEN", "UPDATE", "NOTIFICATION", "KEEPALIVE",
 130 };
 131 #define bgp_type(x) num_or_str(bgptype, sizeof(bgptype)/sizeof(bgptype[0]), (x))
 132
 133 static const char *bgpopt_type[] = {
 134         NULL, "Authentication Information", "Capabilities Advertisement",
 135 };
 136 #define bgp_opttype(x) \
 137         num_or_str(bgpopt_type, sizeof(bgpopt_type)/sizeof(bgpopt_type[0]), (x))
 138
 139 static const char *bgpnotify_major[] = {
 140         NULL, "Message Header Error",
 141         "OPEN Message Error", "UPDATE Message Error",
 142         "Hold Timer Expired", "Finite State Machine Error",
 143         "Cease",
 144 };
 145 #define bgp_notify_major(x) \
 146         num_or_str(bgpnotify_major, \
 147                 sizeof(bgpnotify_major)/sizeof(bgpnotify_major[0]), (x))
 148
 149 static const char *bgpnotify_minor_1[] = {
 150         NULL, "Connection Not Synchronized",
 151         "Bad Message Length", "Bad Message Type",
 152 };
 153
 154 static const char *bgpnotify_minor_2[] = {
 155         NULL, "Unsupported Version Number",
 156         "Bad Peer AS", "Bad BGP Identifier",
 157         "Unsupported Optional Parameter", "Authentication Failure",
 158         "Unacceptable Hold Time",
 159 };
 160
 161 static const char *bgpnotify_minor_3[] = {
 162         NULL, "Malformed Attribute List",
 163         "Unrecognized Well-known Attribute", "Missing Well-known Attribute",
 164         "Attribute Flags Error", "Attribute Length Error",
 165         "Invalid ORIGIN Attribute", "AS Routing Loop",
 166         "Invalid NEXT_HOP Attribute", "Optional Attribute Error",
 167         "Invalid Network Field", "Malformed AS_PATH",
 168 };
 169
 170 static const char **bgpnotify_minor[] = {
 171         NULL, bgpnotify_minor_1, bgpnotify_minor_2, bgpnotify_minor_3,
 172 };
 173 static const int bgpnotify_minor_siz[] = {
 174         0, sizeof(bgpnotify_minor_1)/sizeof(bgpnotify_minor_1[0]),
 175         sizeof(bgpnotify_minor_2)/sizeof(bgpnotify_minor_2[0]),
 176         sizeof(bgpnotify_minor_3)/sizeof(bgpnotify_minor_3[0]),
 177 };
 178
 179 static const char *bgpattr_origin[] = {
 180         "IGP", "EGP", "INCOMPLETE",
 181 };
 182 #define bgp_attr_origin(x) \
 183         num_or_str(bgpattr_origin, \
 184                 sizeof(bgpattr_origin)/sizeof(bgpattr_origin[0]), (x))
 185
 186 static const char *bgpattr_type[] = {
 187         NULL, "ORIGIN", "AS_PATH", "NEXT_HOP",
 188         "MULTI_EXIT_DISC", "LOCAL_PREF", "ATOMIC_AGGREGATE", "AGGREGATOR",
 189         "COMMUNITIES", "ORIGINATOR_ID", "CLUSTER_LIST", "DPA",
 190         "ADVERTISERS", "RCID_PATH", "MP_REACH_NLRI", "MP_UNREACH_NLRI",
 191 };
 192 #define bgp_attr_type(x) \
 193         num_or_str(bgpattr_type, \
 194                 sizeof(bgpattr_type)/sizeof(bgpattr_type[0]), (x))
 195
 196 /* Subsequent address family identifier, RFC2283 section 7 */
 197 #define SAFNUM_RES          0
 198 #define SAFNUM_UNICAST      1
 199 #define SAFNUM_MULTICAST    2
 200 #define SAFNUM_UNIMULTICAST 3
 201 /* labeled BGP RFC3107 */
 202 #define SAFNUM_LABUNICAST   4
 203
 204 static const char *bgpattr_nlri_safi[] = {
 205     "Reserved", "Unicast", "Multicast", "Unicast+Multicast", "labeled Unicast"
 206 };
 207 #define bgp_attr_nlri_safi(x) \
 208         num_or_str(bgpattr_nlri_safi, \
 209                 sizeof(bgpattr_nlri_safi)/sizeof(bgpattr_nlri_safi[0]), (x))
 210
 211 /* well-known community */
 212 #define BGP_COMMUNITY_NO_EXPORT                 0xffffff01
 213 #define BGP_COMMUNITY_NO_ADVERT                 0xffffff02
 214 #define BGP_COMMUNITY_NO_EXPORT_SUBCONFED       0xffffff03
 215
 216 /* RFC1700 address family numbers */
 217 #define AFNUM_INET      1
 218 #define AFNUM_INET6     2
 219 #define AFNUM_NSAP      3
 220 #define AFNUM_HDLC      4
 221 #define AFNUM_BBN1822   5
 222 #define AFNUM_802       6
 223 #define AFNUM_E163      7
 224 #define AFNUM_E164      8
 225 #define AFNUM_F69       9
 226 #define AFNUM_X121      10
 227 #define AFNUM_IPX       11
 228 #define AFNUM_ATALK     12
 229 #define AFNUM_DECNET    13
 230 #define AFNUM_BANYAN    14
 231 #define AFNUM_E164NSAP  15
 232
 233 static const char *afnumber[] = {
 234         "Reserved", "IPv4", "IPv6", "NSAP", "HDLC",
 235         "BBN 1822", "802", "E.163", "E.164", "F.69",
 236         "X.121", "IPX", "Appletalk", "Decnet IV", "Banyan Vines",
 237         "E.164 with NSAP subaddress",
 238 };
 239 #define af_name(x) \
 240         (((x) == 65535) ? afnumber[0] : \
 241                 num_or_str(afnumber, \
 242                         sizeof(afnumber)/sizeof(afnumber[0]), (x)))
 243
 244
 245 static const char *
 246 num_or_str(const char **table, size_t siz, int value)
 247 {
 248         static char buf[20];
 249         if (value < 0 || siz <= value || table[value] == NULL) {
 250                 snprintf(buf, sizeof(buf), "#%d", value);
 251                 return buf;
 252         } else
 253                 return table[value];
 254 }
 255
 256 static const char *
 257 bgp_notify_minor(int major, int minor)
 258 {
 259         static const char **table;
 260         int siz;
 261         static char buf[20];
 262         const char *p;
 263
 264         if (0 <= major
 265          && major < sizeof(bgpnotify_minor)/sizeof(bgpnotify_minor[0])
 266          && bgpnotify_minor[major]) {
 267                 table = bgpnotify_minor[major];
 268                 siz = bgpnotify_minor_siz[major];
 269                 if (0 <= minor && minor < siz && table[minor])
 270                         p = table[minor];
 271                 else
 272                         p = NULL;
 273         } else
 274                 p = NULL;
 275         if (p == NULL) {
 276                 snprintf(buf, sizeof(buf), "#%d", minor);
 277                 return buf;
 278         } else
 279                 return p;
 280 }
 281
 282 static int
 283 decode_prefix4(const u_char *pd, char *buf, u_int buflen)
 284 {
 285         struct in_addr addr;
 286         u_int plen;
 287
 288         plen = pd[0];
 289         if (plen < 0 || 32 < plen)
 290                 return -1;
 291
 292         memset(&addr, 0, sizeof(addr));
 293         memcpy(&addr, &pd[1], (plen + 7) / 8);
 294         if (plen % 8) {
 295                 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
 296                         ((0xff00 >> (plen % 8)) & 0xff);
 297         }
 298         snprintf(buf, buflen, "%s/%d", getname((u_char *)&addr), plen);
 299         return 1 + (plen + 7) / 8;
 300 }
 301
 302 static int
 303 decode_labeled_prefix4(const u_char *pd, char *buf, u_int buflen)
 304 {
 305         struct in_addr addr;
 306         u_int plen;
 307
 308         plen = pd[0];   /* get prefix length */
 309
 310         /* this is one of the weirdnesses of rfc3107
 311            the label length (actually the label + COS bits)
 312            is added of the prefix length;
 313            hence we do nod check for 0-32 but rather
 314            for 24-56 - hannes@juniper.net
 315         */
 316         if (plen < 24 || 56 < plen)
 317                 return -1;
 318         plen-=24; /* adjust prefixlen - labellength */
 319
 320         memset(&addr, 0, sizeof(addr));
 321         memcpy(&addr, &pd[4], (plen + 7) / 8);
 322         if (plen % 8) {
 323                 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
 324                         ((0xff00 >> (plen % 8)) & 0xff);
 325         }
 326         /* the label may get offsetted by 4 bits so lets shift it right */
 327         snprintf(buf, buflen, "%s/%d (label:%u EXP:%u, S:%u)",
 328                  getname((u_char *)&addr),
 329                  plen,
 330                  EXTRACT_24BITS(pd+1)>>4,
 331                  (pd[3]>>1)&7,
 332                  (pd[3]&1));
 333         return 4 + (plen + 7) / 8;
 334 }
 335
 336 #ifdef INET6
 337 static int
 338 decode_prefix6(const u_char *pd, char *buf, u_int buflen)
 339 {
 340         struct in6_addr addr;
 341         u_int plen;
 342
 343         plen = pd[0];
 344         if (plen < 0 || 128 < plen)
 345                 return -1;
 346
 347         memset(&addr, 0, sizeof(addr));
 348         memcpy(&addr, &pd[1], (plen + 7) / 8);
 349         if (plen % 8) {
 350                 addr.s6_addr[(plen + 7) / 8 - 1] &=
 351                         ((0xff00 >> (plen % 8)) & 0xff);
 352         }
 353         snprintf(buf, buflen, "%s/%d", getname6((u_char *)&addr), plen);
 354         return 1 + (plen + 7) / 8;
 355 }
 356 #endif
 357
 358 static void
 359 bgp_attr_print(const struct bgp_attr *attr, const u_char *dat, int len)
 360 {
 361         int i;
 362         u_int16_t af;
 363         u_int8_t safi, snpa;
 364         int advance;
 365         int tlen;
 366         const u_char *p;
 367         char buf[MAXHOSTNAMELEN + 100];
 368
 369         p = dat;
 370
 371         switch (attr->bgpa_type) {
 372         case BGPTYPE_ORIGIN:
 373                 if (len != 1)
 374                         printf(" invalid len");
 375                 else
 376                         printf(" %s", bgp_attr_origin(p[0]));
 377                 break;
 378         case BGPTYPE_AS_PATH:
 379                 if (len % 2) {
 380                         printf(" invalid len");
 381                         break;
 382                 }
 383                 while (p < dat + len) {
 384                         /*
 385                          * under RFC1965, p[0] means:
 386                          * 1: AS_SET 2: AS_SEQUENCE
 387                          * 3: AS_CONFED_SET 4: AS_CONFED_SEQUENCE
 388                          */
 389                         printf(" ");
 390                         if (p[0] == 3 || p[0] == 4)
 391                                 printf("confed");
 392                         printf("%s", (p[0] & 1) ? "{" : "");
 393                         for (i = 0; i < p[1] * 2; i += 2) {
 394                                 printf("%s%u", i == 0 ? "" : " ",
 395                                         EXTRACT_16BITS(&p[2 + i]));
 396                         }
 397                         printf("%s", (p[0] & 1) ? "}" : "");
 398                         p += 2 + p[1] * 2;
 399                 }
 400                 break;
 401         case BGPTYPE_NEXT_HOP:
 402                 if (len != 4)
 403                         printf(" invalid len");
 404                 else
 405                         printf(" %s", getname(p));
 406                 break;
 407         case BGPTYPE_MULTI_EXIT_DISC:
 408         case BGPTYPE_LOCAL_PREF:
 409                 if (len != 4)
 410                         printf(" invalid len");
 411                 else
 412                         printf(" %u", EXTRACT_32BITS(p));
 413                 break;
 414         case BGPTYPE_ATOMIC_AGGREGATE:
 415                 if (len != 0)
 416                         printf(" invalid len");
 417                 break;
 418         case BGPTYPE_AGGREGATOR:
 419                 if (len != 6) {
 420                         printf(" invalid len");
 421                         break;
 422                 }
 423                 printf(" AS #%u, origin %s", EXTRACT_16BITS(p),
 424                         getname(p + 2));
 425                 break;
 426         case BGPTYPE_COMMUNITIES:
 427                 if (len % 4) {
 428                         printf(" invalid len");
 429                         break;
 430                 }
 431                 for (i = 0; i < len; i += 4) {
 432                         u_int32_t comm;
 433                         comm = EXTRACT_32BITS(&p[i]);
 434                         switch (comm) {
 435                         case BGP_COMMUNITY_NO_EXPORT:
 436                                 printf(" NO_EXPORT");
 437                                 break;
 438                         case BGP_COMMUNITY_NO_ADVERT:
 439                                 printf(" NO_ADVERTISE");
 440                                 break;
 441                         case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
 442                                 printf(" NO_EXPORT_SUBCONFED");
 443                                 break;
 444                         default:
 445                                 printf(" (AS #%d value 0x%04x)",
 446                                         (comm >> 16) & 0xffff, comm & 0xffff);
 447                                 break;
 448                         }
 449                 }
 450                 break;
 451         case BGPTYPE_MP_REACH_NLRI:
 452                 af = EXTRACT_16BITS(p);
 453                 safi = p[2];
 454                 if (safi >= 128)
 455                         printf(" %s vendor specific,", af_name(af));
 456                 else {
 457                         printf(" AFI %s SAFI %s,", af_name(af),
 458                                 bgp_attr_nlri_safi(safi));
 459                 }
 460                 p += 3;
 461
 462                 if (af == AFNUM_INET)
 463                         ;
 464 #ifdef INET6
 465                 else if (af == AFNUM_INET6)
 466                         ;
 467 #endif
 468                 else
 469                         break;
 470
 471                 tlen = p[0];
 472                 if (tlen) {
 473                         printf(" nexthop");
 474                         i = 0;
 475                         while (i < tlen) {
 476                                 switch (af) {
 477                                 case AFNUM_INET:
 478                                         printf(" %s", getname(p + 1 + i));
 479                                         i += sizeof(struct in_addr);
 480                                         break;
 481 #ifdef INET6
 482                                 case AFNUM_INET6:
 483                                         printf(" %s", getname6(p + 1 + i));
 484                                         i += sizeof(struct in6_addr);
 485                                         break;
 486 #endif
 487                                 default:
 488                                         printf(" (unknown af)");
 489                                         i = tlen;       /*exit loop*/
 490                                         break;
 491                                 }
 492                         }
 493                         printf(",");
 494                 }
 495                 p += 1 + tlen;
 496
 497                 snpa = p[0];
 498                 p++;
 499                 if (snpa) {
 500                         printf(" %u snpa", snpa);
 501                         for (/*nothing*/; snpa > 0; snpa--) {
 502                                 printf("(%d bytes)", p[0]);
 503                                 p += p[0] + 1;
 504                         }
 505                         printf(",");
 506                 } else {
 507                 printf(" no spna,");
 508                 }
 509
 510                 printf(" NLRI");
 511                 while (len - (p - dat) > 0) {
 512                         switch (af) {
 513                         case AFNUM_INET:
 514                             if(safi==SAFNUM_LABUNICAST) {
 515                                 advance = decode_labeled_prefix4(p, buf, sizeof(buf));
 516                             } else {
 517                                 advance = decode_prefix4(p, buf, sizeof(buf));
 518                             }
 519                             if (advance<0)
 520                                 break;
 521                             printf(" %s", buf);
 522                             break;
 523 #ifdef INET6
 524                         case AFNUM_INET6:
 525                             advance = decode_prefix6(p, buf, sizeof(buf));
 526                             printf(" %s", buf);
 527                             break;
 528 #endif
 529                         default:
 530                             printf(" (unknown af)");
 531                             advance = 0;
 532                             p = dat + len;
 533                             break;
 534                         }
 535
 536                         p += advance;
 537                 }
 538
 539                 break;
 540
 541         case BGPTYPE_MP_UNREACH_NLRI:
 542                 af = EXTRACT_16BITS(p);
 543                 safi = p[2];
 544                 if (safi >= 128)
 545                         printf(" %s vendor specific,", af_name(af));
 546                 else {
 547                         printf(" AFI %s SAFI %s,", af_name(af),
 548                                 bgp_attr_nlri_safi(safi));
 549                 }
 550                 p += 3;
 551
 552                 printf(" Withdraw");
 553                 while (len - (p - dat) > 0) {
 554                         switch (af) {
 555                         case AFNUM_INET:
 556                             if(safi==SAFNUM_LABUNICAST) {
 557                                 advance = decode_labeled_prefix4(p, buf, sizeof(buf));
 558                             } else {
 559                                 advance = decode_prefix4(p, buf, sizeof(buf));
 560                             }
 561                             if (advance<0)
 562                                 break;
 563                             printf(" %s", buf);
 564                             break;
 565 #ifdef INET6
 566                         case AFNUM_INET6:
 567                                 advance = decode_prefix6(p, buf, sizeof(buf));
 568                                 printf(" %s", buf);
 569                                 break;
 570 #endif
 571                         default:
 572                                 printf(" (unknown af)");
 573                                 advance = 0;
 574                                 p = dat + len;
 575                                 break;
 576                         }
 577
 578                         p += advance;
 579                 }
 580                 break;
 581         default:
 582                 break;
 583         }
 584 }
 585
 586 static void
 587 bgp_open_print(const u_char *dat, int length)
 588 {
 589         struct bgp_open bgpo;
 590         struct bgp_opt bgpopt;
 591         int hlen;
 592         const u_char *opt;
 593         int i;
 594
 595         TCHECK2(dat[0], BGP_OPEN_SIZE);
 596         memcpy(&bgpo, dat, BGP_OPEN_SIZE);
 597         hlen = ntohs(bgpo.bgpo_len);
 598
 599         printf(": Version %d,", bgpo.bgpo_version);
 600         printf(" AS #%u,", ntohs(bgpo.bgpo_myas));
 601         printf(" Holdtime %u,", ntohs(bgpo.bgpo_holdtime));
 602         printf(" ID %s,", getname((u_char *)&bgpo.bgpo_id));
 603         printf(" Option length %u", bgpo.bgpo_optlen);
 604
 605         /* ugly! */
 606         opt = &((const struct bgp_open *)dat)->bgpo_optlen;
 607         opt++;
 608
 609         i = 0;
 610         while (i < bgpo.bgpo_optlen) {
 611                 TCHECK2(opt[i], BGP_OPT_SIZE);
 612                 memcpy(&bgpopt, &opt[i], BGP_OPT_SIZE);
 613                 if (i + 2 + bgpopt.bgpopt_len > bgpo.bgpo_optlen) {
 614                         printf(" [|opt %d %d]", bgpopt.bgpopt_len, bgpopt.bgpopt_type);
 615                         break;
 616                 }
 617
 618                 printf(" (option %s, len=%d)", bgp_opttype(bgpopt.bgpopt_type),
 619                         bgpopt.bgpopt_len);
 620                 i += BGP_OPT_SIZE + bgpopt.bgpopt_len;
 621         }
 622         return;
 623 trunc:
 624         printf("[|BGP]");
 625 }
 626
 627 static void
 628 bgp_update_print(const u_char *dat, int length)
 629 {
 630         struct bgp bgp;
 631         struct bgp_attr bgpa;
 632         int hlen;
 633         const u_char *p;
 634         int len;
 635         int i;
 636         int newline;
 637
 638         TCHECK2(dat[0], BGP_SIZE);
 639         memcpy(&bgp, dat, BGP_SIZE);
 640         hlen = ntohs(bgp.bgp_len);
 641         p = dat + BGP_SIZE;     /*XXX*/
 642         printf(":");
 643
 644         /* Unfeasible routes */
 645         len = EXTRACT_16BITS(p);
 646         if (len) {
 647                 /*
 648                  * Without keeping state from the original NLRI message,
 649                  * it's not possible to tell if this a v4 or v6 route,
 650                  * so only try to decode it if we're not v6 enabled.
 651                  */
 652 #ifdef INET6
 653                 printf(" (Withdrawn routes: %d bytes)", len);
 654 #else
 655                 char buf[MAXHOSTNAMELEN + 100];
 656
 657                 TCHECK2(p[2], len);
 658                 i = 2;
 659
 660                 printf(" (Withdrawn routes:");
 661
 662                 while(i < 2 + len) {
 663                         i += decode_prefix4(&p[i], buf, sizeof(buf));
 664                         printf(" %s", buf);
 665                 }
 666                 printf(")\n");
 667 #endif
 668         }
 669         p += 2 + len;
 670
 671         TCHECK2(p[0], 2);
 672         len = EXTRACT_16BITS(p);
 673         if (len) {
 674                 /* do something more useful!*/
 675                 i = 2;
 676                 printf(" (Path attributes:");   /* ) */
 677                 newline = 0;
 678                 while (i < 2 + len) {
 679                         int alen, aoff;
 680
 681                         TCHECK2(p[i], sizeof(bgpa));
 682                         memcpy(&bgpa, &p[i], sizeof(bgpa));
 683                         alen = bgp_attr_len(&bgpa);
 684                         aoff = bgp_attr_off(&bgpa);
 685
 686                         if (vflag && newline)
 687                                 printf("\n\t\t");
 688                         else
 689                                 printf(" ");
 690                         printf("(");            /* ) */
 691                         printf("%s", bgp_attr_type(bgpa.bgpa_type));
 692                         if (bgpa.bgpa_flags) {
 693                                 printf("[%s%s%s%s",
 694                                         bgpa.bgpa_flags & 0x80 ? "O" : "",
 695                                         bgpa.bgpa_flags & 0x40 ? "T" : "",
 696                                         bgpa.bgpa_flags & 0x20 ? "P" : "",
 697                                         bgpa.bgpa_flags & 0x10 ? "E" : "");
 698                                 if (bgpa.bgpa_flags & 0xf)
 699                                         printf("+%x", bgpa.bgpa_flags & 0xf);
 700                                 printf("]");
 701                         }
 702
 703                         bgp_attr_print(&bgpa, &p[i + aoff], alen);
 704                         newline = 1;
 705
 706                         /* ( */
 707                         printf(")");
 708
 709                         i += aoff + alen;
 710                 }
 711
 712                 /* ( */
 713                 printf(")");
 714         }
 715         p += 2 + len;
 716
 717         if (len && dat + length > p)
 718                 printf("\n\t\t");
 719         if (dat + length > p) {
 720                 printf("(NLRI:");       /* ) */
 721                 while (dat + length > p) {
 722                         char buf[MAXHOSTNAMELEN + 100];
 723                         i = decode_prefix4(p, buf, sizeof(buf));
 724                         printf(" %s", buf);
 725                         if (i < 0)
 726                                 break;
 727                         p += i;
 728                 }
 729
 730                 /* ( */
 731                 printf(")");
 732         }
 733         return;
 734 trunc:
 735         printf("[|BGP]");
 736 }
 737
 738 static void
 739 bgp_notification_print(const u_char *dat, int length)
 740 {
 741         struct bgp_notification bgpn;
 742         int hlen;
 743
 744         TCHECK2(dat[0], BGP_NOTIFICATION_SIZE);
 745         memcpy(&bgpn, dat, BGP_NOTIFICATION_SIZE);
 746         hlen = ntohs(bgpn.bgpn_len);
 747
 748         printf(": error %s,", bgp_notify_major(bgpn.bgpn_major));
 749         printf(" subcode %s",
 750                 bgp_notify_minor(bgpn.bgpn_major, bgpn.bgpn_minor));
 751         return;
 752 trunc:
 753         printf("[|BGP]");
 754 }
 755
 756 static void
 757 bgp_header_print(const u_char *dat, int length)
 758 {
 759         struct bgp bgp;
 760
 761         TCHECK2(dat[0], BGP_SIZE);
 762         memcpy(&bgp, dat, BGP_SIZE);
 763         printf("(%s", bgp_type(bgp.bgp_type));          /* ) */
 764
 765         switch (bgp.bgp_type) {
 766         case BGP_OPEN:
 767                 bgp_open_print(dat, length);
 768                 break;
 769         case BGP_UPDATE:
 770                 bgp_update_print(dat, length);
 771                 break;
 772         case BGP_NOTIFICATION:
 773                 bgp_notification_print(dat, length);
 774                 break;
 775         }
 776
 777         /* ( */
 778         printf(")");
 779         return;
 780 trunc:
 781         printf("[|BGP]");
 782 }
 783
 784 void
 785 bgp_print(const u_char *dat, int length)
 786 {
 787         const u_char *p;
 788         const u_char *ep;
 789         const u_char *start;
 790         const u_char marker[] = {
 791                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 792                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 793         };
 794         struct bgp bgp;
 795         u_int16_t hlen;
 796         int newline;
 797
 798         ep = dat + length;
 799         if (snapend < dat + length)
 800                 ep = snapend;
 801
 802         printf(": BGP");
 803
 804         p = dat;
 805         newline = 0;
 806         start = p;
 807         while (p < snapend) {
 808                 if (!TTEST2(p[0], 1))
 809                         break;
 810                 if (p[0] != 0xff) {
 811                         p++;
 812                         continue;
 813                 }
 814
 815                 if (!TTEST2(p[0], sizeof(marker)))
 816                         break;
 817                 if (memcmp(p, marker, sizeof(marker)) != 0) {
 818                         p++;
 819                         continue;
 820                 }
 821
 822                 /* found BGP header */
 823                 TCHECK2(p[0], BGP_SIZE);        /*XXX*/
 824                 memcpy(&bgp, p, BGP_SIZE);
 825
 826                 if (start != p)
 827                         printf(" [|BGP]");
 828
 829                 hlen = ntohs(bgp.bgp_len);
 830                 if (vflag && newline)
 831                         printf("\n\t");
 832                 else
 833                         printf(" ");
 834                 if (TTEST2(p[0], hlen)) {
 835                         bgp_header_print(p, hlen);
 836                         newline = 1;
 837                         p += hlen;
 838                         start = p;
 839                 } else {
 840                         printf("[|BGP %s]", bgp_type(bgp.bgp_type));
 841                         break;
 842                 }
 843         }
 844
 845         return;
 846
 847 trunc:
 848         printf(" [|BGP]");
 849 }