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 1.29 2002-05-24 17:49:29 hannes 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            we also do only read out just one label -
 314            there is no real application for advertisment of
 315            stacked labels in a asingle BGP message
 316         */
 317
 318         plen-=24; /* adjust prefixlen - labellength */
 319
 320         if (plen < 0 || 32 < plen)
 321                 return -1;
 322
 323         memset(&addr, 0, sizeof(addr));
 324         memcpy(&addr, &pd[4], (plen + 7) / 8);
 325         if (plen % 8) {
 326                 ((u_char *)&addr)[(plen + 7) / 8 - 1] &=
 327                         ((0xff00 >> (plen % 8)) & 0xff);
 328         }
 329         /* the label may get offsetted by 4 bits so lets shift it right */
 330         snprintf(buf, buflen, "%s/%d label:%u %s",
 331                  getname((u_char *)&addr),
 332                  plen,
 333                  EXTRACT_24BITS(pd+1)>>4,
 334                  ((pd[3]&1)==0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" );
 335
 336         return 4 + (plen + 7) / 8;
 337 }
 338
 339 #ifdef INET6
 340 static int
 341 decode_prefix6(const u_char *pd, char *buf, u_int buflen)
 342 {
 343         struct in6_addr addr;
 344         u_int plen;
 345
 346         plen = pd[0];
 347         if (plen < 0 || 128 < plen)
 348                 return -1;
 349
 350         memset(&addr, 0, sizeof(addr));
 351         memcpy(&addr, &pd[1], (plen + 7) / 8);
 352         if (plen % 8) {
 353                 addr.s6_addr[(plen + 7) / 8 - 1] &=
 354                         ((0xff00 >> (plen % 8)) & 0xff);
 355         }
 356         snprintf(buf, buflen, "%s/%d", getname6((u_char *)&addr), plen);
 357         return 1 + (plen + 7) / 8;
 358 }
 359 #endif
 360
 361 static void
 362 bgp_attr_print(const struct bgp_attr *attr, const u_char *dat, int len)
 363 {
 364         int i;
 365         u_int16_t af;
 366         u_int8_t safi, snpa;
 367         int advance;
 368         int tlen;
 369         const u_char *p;
 370         char buf[MAXHOSTNAMELEN + 100];
 371
 372         p = dat;
 373
 374         switch (attr->bgpa_type) {
 375         case BGPTYPE_ORIGIN:
 376                 if (len != 1)
 377                         printf(" invalid len");
 378                 else
 379                         printf(" %s", bgp_attr_origin(p[0]));
 380                 break;
 381         case BGPTYPE_AS_PATH:
 382                 if (len % 2) {
 383                         printf(" invalid len");
 384                         break;
 385                 }
 386                 while (p < dat + len) {
 387                         /*
 388                          * under RFC1965, p[0] means:
 389                          * 1: AS_SET 2: AS_SEQUENCE
 390                          * 3: AS_CONFED_SET 4: AS_CONFED_SEQUENCE
 391                          */
 392                         printf(" ");
 393                         if (p[0] == 3 || p[0] == 4)
 394                                 printf("confed");
 395                         printf("%s", (p[0] & 1) ? "{" : "");
 396                         for (i = 0; i < p[1] * 2; i += 2) {
 397                                 printf("%s%u", i == 0 ? "" : " ",
 398                                         EXTRACT_16BITS(&p[2 + i]));
 399                         }
 400                         printf("%s", (p[0] & 1) ? "}" : "");
 401                         p += 2 + p[1] * 2;
 402                 }
 403                 break;
 404         case BGPTYPE_NEXT_HOP:
 405                 if (len != 4)
 406                         printf(" invalid len");
 407                 else
 408                         printf(" %s", getname(p));
 409                 break;
 410         case BGPTYPE_MULTI_EXIT_DISC:
 411         case BGPTYPE_LOCAL_PREF:
 412                 if (len != 4)
 413                         printf(" invalid len");
 414                 else
 415                         printf(" %u", EXTRACT_32BITS(p));
 416                 break;
 417         case BGPTYPE_ATOMIC_AGGREGATE:
 418                 if (len != 0)
 419                         printf(" invalid len");
 420                 break;
 421         case BGPTYPE_AGGREGATOR:
 422                 if (len != 6) {
 423                         printf(" invalid len");
 424                         break;
 425                 }
 426                 printf(" AS #%u, origin %s", EXTRACT_16BITS(p),
 427                         getname(p + 2));
 428                 break;
 429         case BGPTYPE_COMMUNITIES:
 430                 if (len % 4) {
 431                         printf(" invalid len");
 432                         break;
 433                 }
 434                 for (i = 0; i < len; i += 4) {
 435                         u_int32_t comm;
 436                         comm = EXTRACT_32BITS(&p[i]);
 437                         switch (comm) {
 438                         case BGP_COMMUNITY_NO_EXPORT:
 439                                 printf(" NO_EXPORT");
 440                                 break;
 441                         case BGP_COMMUNITY_NO_ADVERT:
 442                                 printf(" NO_ADVERTISE");
 443                                 break;
 444                         case BGP_COMMUNITY_NO_EXPORT_SUBCONFED:
 445                                 printf(" NO_EXPORT_SUBCONFED");
 446                                 break;
 447                         default:
 448                                 printf(" (AS #%d value 0x%04x)",
 449                                         (comm >> 16) & 0xffff, comm & 0xffff);
 450                                 break;
 451                         }
 452                 }
 453                 break;
 454         case BGPTYPE_MP_REACH_NLRI:
 455                 af = EXTRACT_16BITS(p);
 456                 safi = p[2];
 457                 if (safi >= 128)
 458                         printf(" %s vendor specific,", af_name(af));
 459                 else {
 460                         printf(" AFI %s SAFI %s,", af_name(af),
 461                                 bgp_attr_nlri_safi(safi));
 462                 }
 463                 p += 3;
 464
 465                 if (af == AFNUM_INET)
 466                         ;
 467 #ifdef INET6
 468                 else if (af == AFNUM_INET6)
 469                         ;
 470 #endif
 471                 else
 472                         break;
 473
 474                 tlen = p[0];
 475                 if (tlen) {
 476                         printf(" nexthop");
 477                         i = 0;
 478                         while (i < tlen) {
 479                                 switch (af) {
 480                                 case AFNUM_INET:
 481                                         printf(" %s", getname(p + 1 + i));
 482                                         i += sizeof(struct in_addr);
 483                                         break;
 484 #ifdef INET6
 485                                 case AFNUM_INET6:
 486                                         printf(" %s", getname6(p + 1 + i));
 487                                         i += sizeof(struct in6_addr);
 488                                         break;
 489 #endif
 490                                 default:
 491                                         printf(" (unknown af)");
 492                                         i = tlen;       /*exit loop*/
 493                                         break;
 494                                 }
 495                         }
 496                         printf(",");
 497                 }
 498                 p += 1 + tlen;
 499
 500                 snpa = p[0];
 501                 p++;
 502                 if (snpa) {
 503                         printf(" %u snpa", snpa);
 504                         for (/*nothing*/; snpa > 0; snpa--) {
 505                                 printf("(%d bytes)", p[0]);
 506                                 p += p[0] + 1;
 507                         }
 508                         printf(",");
 509                 } else {
 510                 printf(" no spna,");
 511                 }
 512
 513                 printf(" NLRI");
 514                 while (len - (p - dat) > 0) {
 515                         switch (af) {
 516                         case AFNUM_INET:
 517                             if(safi==SAFNUM_LABUNICAST) {
 518                                 advance = decode_labeled_prefix4(p, buf, sizeof(buf));
 519                             } else {
 520                                 advance = decode_prefix4(p, buf, sizeof(buf));
 521                             }
 522                             if (advance<0)
 523                                 break;
 524                             printf(" %s", buf);
 525                             break;
 526 #ifdef INET6
 527                         case AFNUM_INET6:
 528                             advance = decode_prefix6(p, buf, sizeof(buf));
 529                             printf(" %s", buf);
 530                             break;
 531 #endif
 532                         default:
 533                             printf(" (unknown af)");
 534                             advance = 0;
 535                             p = dat + len;
 536                             break;
 537                         }
 538
 539                         p += advance;
 540                 }
 541
 542                 break;
 543
 544         case BGPTYPE_MP_UNREACH_NLRI:
 545                 af = EXTRACT_16BITS(p);
 546                 safi = p[2];
 547                 if (safi >= 128)
 548                         printf(" %s vendor specific,", af_name(af));
 549                 else {
 550                         printf(" AFI %s SAFI %s,", af_name(af),
 551                                 bgp_attr_nlri_safi(safi));
 552                 }
 553                 p += 3;
 554
 555                 printf(" Withdraw");
 556                 while (len - (p - dat) > 0) {
 557                         switch (af) {
 558                         case AFNUM_INET:
 559                             if(safi==SAFNUM_LABUNICAST) {
 560                                 advance = decode_labeled_prefix4(p, buf, sizeof(buf));
 561                             } else {
 562                                 advance = decode_prefix4(p, buf, sizeof(buf));
 563                             }
 564                             if (advance<0)
 565                                 break;
 566                             printf(" %s", buf);
 567                             break;
 568 #ifdef INET6
 569                         case AFNUM_INET6:
 570                                 advance = decode_prefix6(p, buf, sizeof(buf));
 571                                 printf(" %s", buf);
 572                                 break;
 573 #endif
 574                         default:
 575                                 printf(" (unknown af)");
 576                                 advance = 0;
 577                                 p = dat + len;
 578                                 break;
 579                         }
 580
 581                         p += advance;
 582                 }
 583                 break;
 584         default:
 585                 break;
 586         }
 587 }
 588
 589 static void
 590 bgp_open_print(const u_char *dat, int length)
 591 {
 592         struct bgp_open bgpo;
 593         struct bgp_opt bgpopt;
 594         int hlen;
 595         const u_char *opt;
 596         int i;
 597
 598         TCHECK2(dat[0], BGP_OPEN_SIZE);
 599         memcpy(&bgpo, dat, BGP_OPEN_SIZE);
 600         hlen = ntohs(bgpo.bgpo_len);
 601
 602         printf(": Version %d,", bgpo.bgpo_version);
 603         printf(" AS #%u,", ntohs(bgpo.bgpo_myas));
 604         printf(" Holdtime %u,", ntohs(bgpo.bgpo_holdtime));
 605         printf(" ID %s,", getname((u_char *)&bgpo.bgpo_id));
 606         printf(" Option length %u", bgpo.bgpo_optlen);
 607
 608         /* ugly! */
 609         opt = &((const struct bgp_open *)dat)->bgpo_optlen;
 610         opt++;
 611
 612         i = 0;
 613         while (i < bgpo.bgpo_optlen) {
 614                 TCHECK2(opt[i], BGP_OPT_SIZE);
 615                 memcpy(&bgpopt, &opt[i], BGP_OPT_SIZE);
 616                 if (i + 2 + bgpopt.bgpopt_len > bgpo.bgpo_optlen) {
 617                         printf(" [|opt %d %d]", bgpopt.bgpopt_len, bgpopt.bgpopt_type);
 618                         break;
 619                 }
 620
 621                 printf(" (option %s, len=%d)", bgp_opttype(bgpopt.bgpopt_type),
 622                         bgpopt.bgpopt_len);
 623                 i += BGP_OPT_SIZE + bgpopt.bgpopt_len;
 624         }
 625         return;
 626 trunc:
 627         printf("[|BGP]");
 628 }
 629
 630 static void
 631 bgp_update_print(const u_char *dat, int length)
 632 {
 633         struct bgp bgp;
 634         struct bgp_attr bgpa;
 635         int hlen;
 636         const u_char *p;
 637         int len;
 638         int i;
 639         int newline;
 640
 641         TCHECK2(dat[0], BGP_SIZE);
 642         memcpy(&bgp, dat, BGP_SIZE);
 643         hlen = ntohs(bgp.bgp_len);
 644         p = dat + BGP_SIZE;     /*XXX*/
 645         printf(":");
 646
 647         /* Unfeasible routes */
 648         len = EXTRACT_16BITS(p);
 649         if (len) {
 650                 /*
 651                  * Without keeping state from the original NLRI message,
 652                  * it's not possible to tell if this a v4 or v6 route,
 653                  * so only try to decode it if we're not v6 enabled.
 654                  */
 655 #ifdef INET6
 656                 printf(" (Withdrawn routes: %d bytes)", len);
 657 #else
 658                 char buf[MAXHOSTNAMELEN + 100];
 659
 660                 TCHECK2(p[2], len);
 661                 i = 2;
 662
 663                 printf(" (Withdrawn routes:");
 664
 665                 while(i < 2 + len) {
 666                         i += decode_prefix4(&p[i], buf, sizeof(buf));
 667                         printf(" %s", buf);
 668                 }
 669                 printf(")\n");
 670 #endif
 671         }
 672         p += 2 + len;
 673
 674         TCHECK2(p[0], 2);
 675         len = EXTRACT_16BITS(p);
 676         if (len) {
 677                 /* do something more useful!*/
 678                 i = 2;
 679                 printf(" (Path attributes:");   /* ) */
 680                 newline = 0;
 681                 while (i < 2 + len) {
 682                         int alen, aoff;
 683
 684                         TCHECK2(p[i], sizeof(bgpa));
 685                         memcpy(&bgpa, &p[i], sizeof(bgpa));
 686                         alen = bgp_attr_len(&bgpa);
 687                         aoff = bgp_attr_off(&bgpa);
 688
 689                         if (vflag && newline)
 690                                 printf("\n\t\t");
 691                         else
 692                                 printf(" ");
 693                         printf("(");            /* ) */
 694                         printf("%s", bgp_attr_type(bgpa.bgpa_type));
 695                         if (bgpa.bgpa_flags) {
 696                                 printf("[%s%s%s%s",
 697                                         bgpa.bgpa_flags & 0x80 ? "O" : "",
 698                                         bgpa.bgpa_flags & 0x40 ? "T" : "",
 699                                         bgpa.bgpa_flags & 0x20 ? "P" : "",
 700                                         bgpa.bgpa_flags & 0x10 ? "E" : "");
 701                                 if (bgpa.bgpa_flags & 0xf)
 702                                         printf("+%x", bgpa.bgpa_flags & 0xf);
 703                                 printf("]");
 704                         }
 705
 706                         bgp_attr_print(&bgpa, &p[i + aoff], alen);
 707                         newline = 1;
 708
 709                         /* ( */
 710                         printf(")");
 711
 712                         i += aoff + alen;
 713                 }
 714
 715                 /* ( */
 716                 printf(")");
 717         }
 718         p += 2 + len;
 719
 720         if (len && dat + length > p)
 721                 printf("\n\t\t");
 722         if (dat + length > p) {
 723                 printf("(NLRI:");       /* ) */
 724                 while (dat + length > p) {
 725                         char buf[MAXHOSTNAMELEN + 100];
 726                         i = decode_prefix4(p, buf, sizeof(buf));
 727                         printf(" %s", buf);
 728                         if (i < 0)
 729                                 break;
 730                         p += i;
 731                 }
 732
 733                 /* ( */
 734                 printf(")");
 735         }
 736         return;
 737 trunc:
 738         printf("[|BGP]");
 739 }
 740
 741 static void
 742 bgp_notification_print(const u_char *dat, int length)
 743 {
 744         struct bgp_notification bgpn;
 745         int hlen;
 746
 747         TCHECK2(dat[0], BGP_NOTIFICATION_SIZE);
 748         memcpy(&bgpn, dat, BGP_NOTIFICATION_SIZE);
 749         hlen = ntohs(bgpn.bgpn_len);
 750
 751         printf(": error %s,", bgp_notify_major(bgpn.bgpn_major));
 752         printf(" subcode %s",
 753                 bgp_notify_minor(bgpn.bgpn_major, bgpn.bgpn_minor));
 754         return;
 755 trunc:
 756         printf("[|BGP]");
 757 }
 758
 759 static void
 760 bgp_header_print(const u_char *dat, int length)
 761 {
 762         struct bgp bgp;
 763
 764         TCHECK2(dat[0], BGP_SIZE);
 765         memcpy(&bgp, dat, BGP_SIZE);
 766         printf("(%s", bgp_type(bgp.bgp_type));          /* ) */
 767
 768         switch (bgp.bgp_type) {
 769         case BGP_OPEN:
 770                 bgp_open_print(dat, length);
 771                 break;
 772         case BGP_UPDATE:
 773                 bgp_update_print(dat, length);
 774                 break;
 775         case BGP_NOTIFICATION:
 776                 bgp_notification_print(dat, length);
 777                 break;
 778         }
 779
 780         /* ( */
 781         printf(")");
 782         return;
 783 trunc:
 784         printf("[|BGP]");
 785 }
 786
 787 void
 788 bgp_print(const u_char *dat, int length)
 789 {
 790         const u_char *p;
 791         const u_char *ep;
 792         const u_char *start;
 793         const u_char marker[] = {
 794                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 795                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 796         };
 797         struct bgp bgp;
 798         u_int16_t hlen;
 799         int newline;
 800
 801         ep = dat + length;
 802         if (snapend < dat + length)
 803                 ep = snapend;
 804
 805         printf(": BGP");
 806
 807         p = dat;
 808         newline = 0;
 809         start = p;
 810         while (p < snapend) {
 811                 if (!TTEST2(p[0], 1))
 812                         break;
 813                 if (p[0] != 0xff) {
 814                         p++;
 815                         continue;
 816                 }
 817
 818                 if (!TTEST2(p[0], sizeof(marker)))
 819                         break;
 820                 if (memcmp(p, marker, sizeof(marker)) != 0) {
 821                         p++;
 822                         continue;
 823                 }
 824
 825                 /* found BGP header */
 826                 TCHECK2(p[0], BGP_SIZE);        /*XXX*/
 827                 memcpy(&bgp, p, BGP_SIZE);
 828
 829                 if (start != p)
 830                         printf(" [|BGP]");
 831
 832                 hlen = ntohs(bgp.bgp_len);
 833                 if (vflag && newline)
 834                         printf("\n\t");
 835                 else
 836                         printf(" ");
 837                 if (TTEST2(p[0], hlen)) {
 838                         bgp_header_print(p, hlen);
 839                         newline = 1;
 840                         p += hlen;
 841                         start = p;
 842                 } else {
 843                         printf("[|BGP %s]", bgp_type(bgp.bgp_type));
 844                         break;
 845                 }
 846         }
 847
 848         return;
 849
 850 trunc:
 851         printf(" [|BGP]");
 852 }