1 /* 2 * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 1995, 1996 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that: (1) source code distributions 7 * retain the above copyright notice and this paragraph in its entirety, (2) 8 * distributions including binary code include the above copyright notice and 9 * this paragraph in its entirety in the documentation or other materials 10 * provided with the distribution, and (3) all advertising materials mentioning 11 * features or use of this software display the following acknowledgement: 12 * ``This product includes software developed by the University of California, 13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 14 * the University nor the names of its contributors may be used to endorse 15 * or promote products derived from this software without specific prior 16 * written permission. 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 20 * 21 * $FreeBSD$ 22 */ 23 24 #ifndef lint 25 static const char rcsid[] _U_ = 26 "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.81.2.2 2005/07/01 16:13:37 hannes Exp $ (LBL)"; 27 #endif 28 29 #ifdef HAVE_CONFIG_H 30 #include "config.h" 31 #endif 32 33 #include <tcpdump-stdinc.h> 34 35 #include <stdio.h> 36 #include <string.h> 37 38 #include "interface.h" 39 #include "addrtoname.h" 40 #include "extract.h" /* must come after interface.h */ 41 42 #include "ip.h" 43 #include "udp.h" 44 #include "ipproto.h" 45 #include "mpls.h" 46 47 /* 48 * Interface Control Message Protocol Definitions. 49 * Per RFC 792, September 1981. 50 */ 51 52 /* 53 * Structure of an icmp header. 54 */ 55 struct icmp { 56 u_int8_t icmp_type; /* type of message, see below */ 57 u_int8_t icmp_code; /* type sub code */ 58 u_int16_t icmp_cksum; /* ones complement cksum of struct */ 59 union { 60 u_int8_t ih_pptr; /* ICMP_PARAMPROB */ 61 struct in_addr ih_gwaddr; /* ICMP_REDIRECT */ 62 struct ih_idseq { 63 u_int16_t icd_id; 64 u_int16_t icd_seq; 65 } ih_idseq; 66 u_int32_t ih_void; 67 68 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */ 69 struct ih_pmtu { 70 u_int16_t ipm_void; 71 u_int16_t ipm_nextmtu; 72 } ih_pmtu; 73 } icmp_hun; 74 #define icmp_pptr icmp_hun.ih_pptr 75 #define icmp_gwaddr icmp_hun.ih_gwaddr 76 #define icmp_id icmp_hun.ih_idseq.icd_id 77 #define icmp_seq icmp_hun.ih_idseq.icd_seq 78 #define icmp_void icmp_hun.ih_void 79 #define icmp_pmvoid icmp_hun.ih_pmtu.ipm_void 80 #define icmp_nextmtu icmp_hun.ih_pmtu.ipm_nextmtu 81 union { 82 struct id_ts { 83 u_int32_t its_otime; 84 u_int32_t its_rtime; 85 u_int32_t its_ttime; 86 } id_ts; 87 struct id_ip { 88 struct ip idi_ip; 89 /* options and then 64 bits of data */ 90 } id_ip; 91 struct mpls_ext { 92 u_int8_t legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ 93 u_int8_t version_res[2]; 94 u_int8_t checksum[2]; 95 u_int8_t data[1]; 96 } mpls_ext; 97 u_int32_t id_mask; 98 u_int8_t id_data[1]; 99 } icmp_dun; 100 #define icmp_otime icmp_dun.id_ts.its_otime 101 #define icmp_rtime icmp_dun.id_ts.its_rtime 102 #define icmp_ttime icmp_dun.id_ts.its_ttime 103 #define icmp_ip icmp_dun.id_ip.idi_ip 104 #define icmp_mask icmp_dun.id_mask 105 #define icmp_data icmp_dun.id_data 106 #define icmp_mpls_ext_version icmp_dun.mpls_ext.version_res 107 #define icmp_mpls_ext_checksum icmp_dun.mpls_ext.checksum 108 #define icmp_mpls_ext_data icmp_dun.mpls_ext.data 109 }; 110 111 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) 112 #define ICMP_MPLS_EXT_VERSION 2 113 114 /* 115 * Lower bounds on packet lengths for various types. 116 * For the error advice packets must first insure that the 117 * packet is large enought to contain the returned ip header. 118 * Only then can we do the check to see if 64 bits of packet 119 * data have been returned, since we need to check the returned 120 * ip header length. 121 */ 122 #define ICMP_MINLEN 8 /* abs minimum */ 123 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-icmp-mpls-02 */ 124 #define ICMP_TSLEN (8 + 3 * sizeof (u_int32_t)) /* timestamp */ 125 #define ICMP_MASKLEN 12 /* address mask */ 126 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */ 127 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8) 128 /* N.B.: must separately check that ip_hl >= 5 */ 129 130 /* 131 * Definition of type and code field values. 132 */ 133 #define ICMP_ECHOREPLY 0 /* echo reply */ 134 #define ICMP_UNREACH 3 /* dest unreachable, codes: */ 135 #define ICMP_UNREACH_NET 0 /* bad net */ 136 #define ICMP_UNREACH_HOST 1 /* bad host */ 137 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */ 138 #define ICMP_UNREACH_PORT 3 /* bad port */ 139 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */ 140 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */ 141 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */ 142 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */ 143 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */ 144 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */ 145 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */ 146 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */ 147 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */ 148 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */ 149 #define ICMP_REDIRECT 5 /* shorter route, codes: */ 150 #define ICMP_REDIRECT_NET 0 /* for network */ 151 #define ICMP_REDIRECT_HOST 1 /* for host */ 152 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */ 153 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */ 154 #define ICMP_ECHO 8 /* echo service */ 155 #define ICMP_ROUTERADVERT 9 /* router advertisement */ 156 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */ 157 #define ICMP_TIMXCEED 11 /* time exceeded, code: */ 158 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */ 159 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */ 160 #define ICMP_PARAMPROB 12 /* ip header bad */ 161 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */ 162 #define ICMP_TSTAMP 13 /* timestamp request */ 163 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */ 164 #define ICMP_IREQ 15 /* information request */ 165 #define ICMP_IREQREPLY 16 /* information reply */ 166 #define ICMP_MASKREQ 17 /* address mask request */ 167 #define ICMP_MASKREPLY 18 /* address mask reply */ 168 169 #define ICMP_MAXTYPE 18 170 171 #define ICMP_INFOTYPE(type) \ 172 ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \ 173 (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \ 174 (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \ 175 (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \ 176 (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY) 177 #define ICMP_MPLS_EXT_TYPE(type) \ 178 ((type) == ICMP_UNREACH || (type) == ICMP_TIMXCEED) 179 /* rfc1700 */ 180 #ifndef ICMP_UNREACH_NET_UNKNOWN 181 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */ 182 #endif 183 #ifndef ICMP_UNREACH_HOST_UNKNOWN 184 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */ 185 #endif 186 #ifndef ICMP_UNREACH_ISOLATED 187 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */ 188 #endif 189 #ifndef ICMP_UNREACH_NET_PROHIB 190 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */ 191 #endif 192 #ifndef ICMP_UNREACH_HOST_PROHIB 193 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */ 194 #endif 195 #ifndef ICMP_UNREACH_TOSNET 196 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */ 197 #endif 198 #ifndef ICMP_UNREACH_TOSHOST 199 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */ 200 #endif 201 202 /* rfc1716 */ 203 #ifndef ICMP_UNREACH_FILTER_PROHIB 204 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */ 205 #endif 206 #ifndef ICMP_UNREACH_HOST_PRECEDENCE 207 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */ 208 #endif 209 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF 210 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */ 211 #endif 212 213 /* Most of the icmp types */ 214 static struct tok icmp2str[] = { 215 { ICMP_ECHOREPLY, "echo reply" }, 216 { ICMP_SOURCEQUENCH, "source quench" }, 217 { ICMP_ECHO, "echo request" }, 218 { ICMP_ROUTERSOLICIT, "router solicitation" }, 219 { ICMP_TSTAMP, "time stamp request" }, 220 { ICMP_TSTAMPREPLY, "time stamp reply" }, 221 { ICMP_IREQ, "information request" }, 222 { ICMP_IREQREPLY, "information reply" }, 223 { ICMP_MASKREQ, "address mask request" }, 224 { 0, NULL } 225 }; 226 227 /* Formats for most of the ICMP_UNREACH codes */ 228 static struct tok unreach2str[] = { 229 { ICMP_UNREACH_NET, "net %s unreachable" }, 230 { ICMP_UNREACH_HOST, "host %s unreachable" }, 231 { ICMP_UNREACH_SRCFAIL, 232 "%s unreachable - source route failed" }, 233 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" }, 234 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" }, 235 { ICMP_UNREACH_ISOLATED, 236 "%s unreachable - source host isolated" }, 237 { ICMP_UNREACH_NET_PROHIB, 238 "net %s unreachable - admin prohibited" }, 239 { ICMP_UNREACH_HOST_PROHIB, 240 "host %s unreachable - admin prohibited" }, 241 { ICMP_UNREACH_TOSNET, 242 "net %s unreachable - tos prohibited" }, 243 { ICMP_UNREACH_TOSHOST, 244 "host %s unreachable - tos prohibited" }, 245 { ICMP_UNREACH_FILTER_PROHIB, 246 "host %s unreachable - admin prohibited filter" }, 247 { ICMP_UNREACH_HOST_PRECEDENCE, 248 "host %s unreachable - host precedence violation" }, 249 { ICMP_UNREACH_PRECEDENCE_CUTOFF, 250 "host %s unreachable - precedence cutoff" }, 251 { 0, NULL } 252 }; 253 254 /* Formats for the ICMP_REDIRECT codes */ 255 static struct tok type2str[] = { 256 { ICMP_REDIRECT_NET, "redirect %s to net %s" }, 257 { ICMP_REDIRECT_HOST, "redirect %s to host %s" }, 258 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" }, 259 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" }, 260 { 0, NULL } 261 }; 262 263 /* rfc1191 */ 264 struct mtu_discovery { 265 u_int16_t unused; 266 u_int16_t nexthopmtu; 267 }; 268 269 /* rfc1256 */ 270 struct ih_rdiscovery { 271 u_int8_t ird_addrnum; 272 u_int8_t ird_addrsiz; 273 u_int16_t ird_lifetime; 274 }; 275 276 struct id_rdiscovery { 277 u_int32_t ird_addr; 278 u_int32_t ird_pref; 279 }; 280 281 /* draft-bonica-icmp-mpls-02 */ 282 struct icmp_mpls_ext_object_header_t { 283 u_int8_t length[2]; 284 u_int8_t class_num; 285 u_int8_t ctype; 286 }; 287 288 static const struct tok icmp_mpls_ext_obj_values[] = { 289 { 1, "MPLS Stack Entry" }, 290 { 2, "Extended Payload" }, 291 { 0, NULL} 292 }; 293 294 /* prototypes */ 295 const char *icmp_tstamp_print(u_int); 296 297 /* print the milliseconds since midnight UTC */ 298 const char * 299 icmp_tstamp_print(u_int tstamp) { 300 u_int msec,sec,min,hrs; 301 302 static char buf[64]; 303 304 msec = tstamp % 1000; 305 sec = tstamp / 1000; 306 min = sec / 60; sec -= min * 60; 307 hrs = min / 60; min -= hrs * 60; 308 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec); 309 return buf; 310 } 311 312 void 313 icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented) 314 { 315 char *cp; 316 const struct icmp *dp; 317 const struct ip *ip; 318 const char *str, *fmt; 319 const struct ip *oip; 320 const struct udphdr *ouh; 321 const u_int8_t *obj_tptr; 322 u_int32_t raw_label; 323 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header; 324 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype; 325 char buf[MAXHOSTNAMELEN + 100]; 326 327 dp = (struct icmp *)bp; 328 ip = (struct ip *)bp2; 329 str = buf; 330 331 TCHECK(dp->icmp_code); 332 switch (dp->icmp_type) { 333 334 case ICMP_ECHO: 335 case ICMP_ECHOREPLY: 336 TCHECK(dp->icmp_seq); 337 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u", 338 dp->icmp_type == ICMP_ECHO ? 339 "request" : "reply", 340 EXTRACT_16BITS(&dp->icmp_id), 341 EXTRACT_16BITS(&dp->icmp_seq)); 342 break; 343 344 case ICMP_UNREACH: 345 TCHECK(dp->icmp_ip.ip_dst); 346 switch (dp->icmp_code) { 347 348 case ICMP_UNREACH_PROTOCOL: 349 TCHECK(dp->icmp_ip.ip_p); 350 (void)snprintf(buf, sizeof(buf), 351 "%s protocol %d unreachable", 352 ipaddr_string(&dp->icmp_ip.ip_dst), 353 dp->icmp_ip.ip_p); 354 break; 355 356 case ICMP_UNREACH_PORT: 357 TCHECK(dp->icmp_ip.ip_p); 358 oip = &dp->icmp_ip; 359 hlen = IP_HL(oip) * 4; 360 ouh = (struct udphdr *)(((u_char *)oip) + hlen); 361 TCHECK(ouh->uh_dport); 362 dport = EXTRACT_16BITS(&ouh->uh_dport); 363 switch (oip->ip_p) { 364 365 case IPPROTO_TCP: 366 (void)snprintf(buf, sizeof(buf), 367 "%s tcp port %s unreachable", 368 ipaddr_string(&oip->ip_dst), 369 tcpport_string(dport)); 370 break; 371 372 case IPPROTO_UDP: 373 (void)snprintf(buf, sizeof(buf), 374 "%s udp port %s unreachable", 375 ipaddr_string(&oip->ip_dst), 376 udpport_string(dport)); 377 break; 378 379 default: 380 (void)snprintf(buf, sizeof(buf), 381 "%s protocol %d port %d unreachable", 382 ipaddr_string(&oip->ip_dst), 383 oip->ip_p, dport); 384 break; 385 } 386 break; 387 388 case ICMP_UNREACH_NEEDFRAG: 389 { 390 register const struct mtu_discovery *mp; 391 mp = (struct mtu_discovery *)&dp->icmp_void; 392 mtu = EXTRACT_16BITS(&mp->nexthopmtu); 393 if (mtu) { 394 (void)snprintf(buf, sizeof(buf), 395 "%s unreachable - need to frag (mtu %d)", 396 ipaddr_string(&dp->icmp_ip.ip_dst), mtu); 397 } else { 398 (void)snprintf(buf, sizeof(buf), 399 "%s unreachable - need to frag", 400 ipaddr_string(&dp->icmp_ip.ip_dst)); 401 } 402 } 403 break; 404 405 default: 406 fmt = tok2str(unreach2str, "#%d %%s unreachable", 407 dp->icmp_code); 408 (void)snprintf(buf, sizeof(buf), fmt, 409 ipaddr_string(&dp->icmp_ip.ip_dst)); 410 break; 411 } 412 break; 413 414 case ICMP_REDIRECT: 415 TCHECK(dp->icmp_ip.ip_dst); 416 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s", 417 dp->icmp_code); 418 (void)snprintf(buf, sizeof(buf), fmt, 419 ipaddr_string(&dp->icmp_ip.ip_dst), 420 ipaddr_string(&dp->icmp_gwaddr)); 421 break; 422 423 case ICMP_ROUTERADVERT: 424 { 425 register const struct ih_rdiscovery *ihp; 426 register const struct id_rdiscovery *idp; 427 u_int lifetime, num, size; 428 429 (void)snprintf(buf, sizeof(buf), "router advertisement"); 430 cp = buf + strlen(buf); 431 432 ihp = (struct ih_rdiscovery *)&dp->icmp_void; 433 TCHECK(*ihp); 434 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); 435 cp = buf + strlen(buf); 436 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime); 437 if (lifetime < 60) { 438 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u", 439 lifetime); 440 } else if (lifetime < 60 * 60) { 441 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u", 442 lifetime / 60, lifetime % 60); 443 } else { 444 (void)snprintf(cp, sizeof(buf) - (cp - buf), 445 "%u:%02u:%02u", 446 lifetime / 3600, 447 (lifetime % 3600) / 60, 448 lifetime % 60); 449 } 450 cp = buf + strlen(buf); 451 452 num = ihp->ird_addrnum; 453 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num); 454 cp = buf + strlen(buf); 455 456 size = ihp->ird_addrsiz; 457 if (size != 2) { 458 (void)snprintf(cp, sizeof(buf) - (cp - buf), 459 " [size %d]", size); 460 break; 461 } 462 idp = (struct id_rdiscovery *)&dp->icmp_data; 463 while (num-- > 0) { 464 TCHECK(*idp); 465 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", 466 ipaddr_string(&idp->ird_addr), 467 EXTRACT_32BITS(&idp->ird_pref)); 468 cp = buf + strlen(buf); 469 ++idp; 470 } 471 } 472 break; 473 474 case ICMP_TIMXCEED: 475 TCHECK(dp->icmp_ip.ip_dst); 476 switch (dp->icmp_code) { 477 478 case ICMP_TIMXCEED_INTRANS: 479 str = "time exceeded in-transit"; 480 break; 481 482 case ICMP_TIMXCEED_REASS: 483 str = "ip reassembly time exceeded"; 484 break; 485 486 default: 487 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d", 488 dp->icmp_code); 489 break; 490 } 491 break; 492 493 case ICMP_PARAMPROB: 494 if (dp->icmp_code) 495 (void)snprintf(buf, sizeof(buf), 496 "parameter problem - code %d", dp->icmp_code); 497 else { 498 TCHECK(dp->icmp_pptr); 499 (void)snprintf(buf, sizeof(buf), 500 "parameter problem - octet %d", dp->icmp_pptr); 501 } 502 break; 503 504 case ICMP_MASKREPLY: 505 TCHECK(dp->icmp_mask); 506 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", 507 EXTRACT_32BITS(&dp->icmp_mask)); 508 break; 509 510 case ICMP_TSTAMP: 511 TCHECK(dp->icmp_seq); 512 (void)snprintf(buf, sizeof(buf), 513 "time stamp query id %u seq %u", 514 EXTRACT_16BITS(&dp->icmp_id), 515 EXTRACT_16BITS(&dp->icmp_seq)); 516 break; 517 518 case ICMP_TSTAMPREPLY: 519 TCHECK(dp->icmp_ttime); 520 (void)snprintf(buf, sizeof(buf), 521 "time stamp reply id %u seq %u: org %s", 522 EXTRACT_16BITS(&dp->icmp_id), 523 EXTRACT_16BITS(&dp->icmp_seq), 524 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime))); 525 526 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", 527 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime))); 528 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", 529 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime))); 530 break; 531 532 default: 533 str = tok2str(icmp2str, "type-#%d", dp->icmp_type); 534 break; 535 } 536 (void)printf("ICMP %s, length %u", str, plen); 537 if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ 538 u_int16_t sum, icmp_sum; 539 if (TTEST2(*bp, plen)) { 540 sum = in_cksum((u_short*)dp, plen, 0); 541 if (sum != 0) { 542 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum); 543 (void)printf(" (wrong icmp cksum %x (->%x)!)", 544 icmp_sum, 545 in_cksum_shouldbe(icmp_sum, sum)); 546 } 547 } 548 } 549 if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) { 550 bp += 8; 551 (void)printf("\n\t"); 552 ip = (struct ip *)bp; 553 snaplen = snapend - bp; 554 ip_print(gndo, bp, EXTRACT_16BITS(&ip->ip_len)); 555 } 556 557 if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) { 558 559 TCHECK(*(dp->icmp_mpls_ext_version)); 560 printf("\n\tMPLS extension v%u",ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version))); 561 562 /* 563 * Sanity checking of the header. 564 */ 565 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version)) != ICMP_MPLS_EXT_VERSION) { 566 printf(" packet not supported"); 567 return; 568 } 569 570 hlen = plen - ICMP_EXTD_MINLEN; 571 TCHECK2(*(dp->icmp_mpls_ext_checksum), 2); 572 printf(", checksum 0x%04x (unverified), length %u", /* FIXME */ 573 EXTRACT_16BITS(dp->icmp_mpls_ext_checksum), 574 hlen); 575 576 hlen -= 4; /* subtract common header size */ 577 obj_tptr = (u_int8_t *)dp->icmp_mpls_ext_data; 578 579 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) { 580 581 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr; 582 TCHECK(*icmp_mpls_ext_object_header); 583 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length); 584 obj_class_num = icmp_mpls_ext_object_header->class_num; 585 obj_ctype = icmp_mpls_ext_object_header->ctype; 586 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t); 587 588 printf("\n\t %s Object (%u), Class-Type: %u, length %u", 589 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num), 590 obj_class_num, 591 obj_ctype, 592 obj_tlen); 593 594 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */ 595 if (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t)) 596 break; 597 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t); 598 599 switch (obj_class_num) { 600 case 1: 601 switch(obj_ctype) { 602 case 1: 603 TCHECK2(*obj_tptr, 4); 604 raw_label = EXTRACT_32BITS(obj_tptr); 605 printf("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)); 606 if (MPLS_STACK(raw_label)) 607 printf(", [S]"); 608 printf(", ttl %u", MPLS_TTL(raw_label)); 609 break; 610 default: 611 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 612 } 613 break; 614 615 /* 616 * FIXME those are the defined objects that lack a decoder 617 * you are welcome to contribute code ;-) 618 */ 619 case 2: 620 default: 621 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 622 break; 623 } 624 if (hlen < obj_tlen) 625 break; 626 hlen -= obj_tlen; 627 obj_tptr += obj_tlen; 628 } 629 } 630 631 return; 632 trunc: 633 fputs("[|icmp]", stdout); 634 } 635