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 22#include <sys/cdefs.h> 23#ifndef lint 24#if 0 25static const char rcsid[] _U_ = 26 "@(#) Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.87 2007-09-13 17:42:31 guy Exp (LBL)"; 27#else 28__RCSID("$NetBSD: print-icmp.c,v 1.2 2010/12/05 05:11:30 christos Exp $"); 29#endif 30#endif 31 32#ifdef HAVE_CONFIG_H 33#include "config.h" 34#endif 35 36#include <tcpdump-stdinc.h> 37 38#include <stdio.h> 39#include <string.h> 40 41#include "interface.h" 42#include "addrtoname.h" 43#include "extract.h" /* must come after interface.h */ 44 45#include "ip.h" 46#include "udp.h" 47#include "ipproto.h" 48#include "mpls.h" 49 50/* 51 * Interface Control Message Protocol Definitions. 52 * Per RFC 792, September 1981. 53 */ 54 55/* 56 * Structure of an icmp header. 57 */ 58struct icmp { 59 u_int8_t icmp_type; /* type of message, see below */ 60 u_int8_t icmp_code; /* type sub code */ 61 u_int16_t icmp_cksum; /* ones complement cksum of struct */ 62 union { 63 u_int8_t ih_pptr; /* ICMP_PARAMPROB */ 64 struct in_addr ih_gwaddr; /* ICMP_REDIRECT */ 65 struct ih_idseq { 66 u_int16_t icd_id; 67 u_int16_t icd_seq; 68 } ih_idseq; 69 u_int32_t ih_void; 70 } icmp_hun; 71#define icmp_pptr icmp_hun.ih_pptr 72#define icmp_gwaddr icmp_hun.ih_gwaddr 73#define icmp_id icmp_hun.ih_idseq.icd_id 74#define icmp_seq icmp_hun.ih_idseq.icd_seq 75#define icmp_void icmp_hun.ih_void 76 union { 77 struct id_ts { 78 u_int32_t its_otime; 79 u_int32_t its_rtime; 80 u_int32_t its_ttime; 81 } id_ts; 82 struct id_ip { 83 struct ip idi_ip; 84 /* options and then 64 bits of data */ 85 } id_ip; 86 u_int32_t id_mask; 87 u_int8_t id_data[1]; 88 } icmp_dun; 89#define icmp_otime icmp_dun.id_ts.its_otime 90#define icmp_rtime icmp_dun.id_ts.its_rtime 91#define icmp_ttime icmp_dun.id_ts.its_ttime 92#define icmp_ip icmp_dun.id_ip.idi_ip 93#define icmp_mask icmp_dun.id_mask 94#define icmp_data icmp_dun.id_data 95}; 96 97#define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) 98#define ICMP_MPLS_EXT_VERSION 2 99 100/* 101 * Lower bounds on packet lengths for various types. 102 * For the error advice packets must first insure that the 103 * packet is large enought to contain the returned ip header. 104 * Only then can we do the check to see if 64 bits of packet 105 * data have been returned, since we need to check the returned 106 * ip header length. 107 */ 108#define ICMP_MINLEN 8 /* abs minimum */ 109#define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */ 110#define ICMP_TSLEN (8 + 3 * sizeof (u_int32_t)) /* timestamp */ 111#define ICMP_MASKLEN 12 /* address mask */ 112#define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */ 113#define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8) 114 /* N.B.: must separately check that ip_hl >= 5 */ 115 116/* 117 * Definition of type and code field values. 118 */ 119#define ICMP_ECHOREPLY 0 /* echo reply */ 120#define ICMP_UNREACH 3 /* dest unreachable, codes: */ 121#define ICMP_UNREACH_NET 0 /* bad net */ 122#define ICMP_UNREACH_HOST 1 /* bad host */ 123#define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */ 124#define ICMP_UNREACH_PORT 3 /* bad port */ 125#define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */ 126#define ICMP_UNREACH_SRCFAIL 5 /* src route failed */ 127#define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */ 128#define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */ 129#define ICMP_UNREACH_ISOLATED 8 /* src host isolated */ 130#define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */ 131#define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */ 132#define ICMP_UNREACH_TOSNET 11 /* bad tos for net */ 133#define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */ 134#define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */ 135#define ICMP_REDIRECT 5 /* shorter route, codes: */ 136#define ICMP_REDIRECT_NET 0 /* for network */ 137#define ICMP_REDIRECT_HOST 1 /* for host */ 138#define ICMP_REDIRECT_TOSNET 2 /* for tos and net */ 139#define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */ 140#define ICMP_ECHO 8 /* echo service */ 141#define ICMP_ROUTERADVERT 9 /* router advertisement */ 142#define ICMP_ROUTERSOLICIT 10 /* router solicitation */ 143#define ICMP_TIMXCEED 11 /* time exceeded, code: */ 144#define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */ 145#define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */ 146#define ICMP_PARAMPROB 12 /* ip header bad */ 147#define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */ 148#define ICMP_TSTAMP 13 /* timestamp request */ 149#define ICMP_TSTAMPREPLY 14 /* timestamp reply */ 150#define ICMP_IREQ 15 /* information request */ 151#define ICMP_IREQREPLY 16 /* information reply */ 152#define ICMP_MASKREQ 17 /* address mask request */ 153#define ICMP_MASKREPLY 18 /* address mask reply */ 154 155#define ICMP_MAXTYPE 18 156 157#define ICMP_INFOTYPE(type) \ 158 ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \ 159 (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \ 160 (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \ 161 (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \ 162 (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY) 163#define ICMP_MPLS_EXT_TYPE(type) \ 164 ((type) == ICMP_UNREACH || \ 165 (type) == ICMP_TIMXCEED || \ 166 (type) == ICMP_PARAMPROB) 167/* rfc1700 */ 168#ifndef ICMP_UNREACH_NET_UNKNOWN 169#define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */ 170#endif 171#ifndef ICMP_UNREACH_HOST_UNKNOWN 172#define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */ 173#endif 174#ifndef ICMP_UNREACH_ISOLATED 175#define ICMP_UNREACH_ISOLATED 8 /* source host isolated */ 176#endif 177#ifndef ICMP_UNREACH_NET_PROHIB 178#define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */ 179#endif 180#ifndef ICMP_UNREACH_HOST_PROHIB 181#define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */ 182#endif 183#ifndef ICMP_UNREACH_TOSNET 184#define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */ 185#endif 186#ifndef ICMP_UNREACH_TOSHOST 187#define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */ 188#endif 189 190/* rfc1716 */ 191#ifndef ICMP_UNREACH_FILTER_PROHIB 192#define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */ 193#endif 194#ifndef ICMP_UNREACH_HOST_PRECEDENCE 195#define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */ 196#endif 197#ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF 198#define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */ 199#endif 200 201/* Most of the icmp types */ 202static struct tok icmp2str[] = { 203 { ICMP_ECHOREPLY, "echo reply" }, 204 { ICMP_SOURCEQUENCH, "source quench" }, 205 { ICMP_ECHO, "echo request" }, 206 { ICMP_ROUTERSOLICIT, "router solicitation" }, 207 { ICMP_TSTAMP, "time stamp request" }, 208 { ICMP_TSTAMPREPLY, "time stamp reply" }, 209 { ICMP_IREQ, "information request" }, 210 { ICMP_IREQREPLY, "information reply" }, 211 { ICMP_MASKREQ, "address mask request" }, 212 { 0, NULL } 213}; 214 215/* Formats for most of the ICMP_UNREACH codes */ 216static struct tok unreach2str[] = { 217 { ICMP_UNREACH_NET, "net %s unreachable" }, 218 { ICMP_UNREACH_HOST, "host %s unreachable" }, 219 { ICMP_UNREACH_SRCFAIL, 220 "%s unreachable - source route failed" }, 221 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" }, 222 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" }, 223 { ICMP_UNREACH_ISOLATED, 224 "%s unreachable - source host isolated" }, 225 { ICMP_UNREACH_NET_PROHIB, 226 "net %s unreachable - admin prohibited" }, 227 { ICMP_UNREACH_HOST_PROHIB, 228 "host %s unreachable - admin prohibited" }, 229 { ICMP_UNREACH_TOSNET, 230 "net %s unreachable - tos prohibited" }, 231 { ICMP_UNREACH_TOSHOST, 232 "host %s unreachable - tos prohibited" }, 233 { ICMP_UNREACH_FILTER_PROHIB, 234 "host %s unreachable - admin prohibited filter" }, 235 { ICMP_UNREACH_HOST_PRECEDENCE, 236 "host %s unreachable - host precedence violation" }, 237 { ICMP_UNREACH_PRECEDENCE_CUTOFF, 238 "host %s unreachable - precedence cutoff" }, 239 { 0, NULL } 240}; 241 242/* Formats for the ICMP_REDIRECT codes */ 243static struct tok type2str[] = { 244 { ICMP_REDIRECT_NET, "redirect %s to net %s" }, 245 { ICMP_REDIRECT_HOST, "redirect %s to host %s" }, 246 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" }, 247 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" }, 248 { 0, NULL } 249}; 250 251/* rfc1191 */ 252struct mtu_discovery { 253 u_int16_t unused; 254 u_int16_t nexthopmtu; 255}; 256 257/* rfc1256 */ 258struct ih_rdiscovery { 259 u_int8_t ird_addrnum; 260 u_int8_t ird_addrsiz; 261 u_int16_t ird_lifetime; 262}; 263 264struct id_rdiscovery { 265 u_int32_t ird_addr; 266 u_int32_t ird_pref; 267}; 268 269/* 270 * draft-bonica-internet-icmp-08 271 * 272 * The Destination Unreachable, Time Exceeded 273 * and Parameter Problem messages are slighly changed as per 274 * the above draft. A new Length field gets added to give 275 * the caller an idea about the length of the piggypacked 276 * IP packet before the MPLS extension header starts. 277 * 278 * The Length field represents length of the padded "original datagram" 279 * field measured in 32-bit words. 280 * 281 * 0 1 2 3 282 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 283 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 284 * | Type | Code | Checksum | 285 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 286 * | unused | Length | unused | 287 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 * | Internet Header + leading octets of original datagram | 289 * | | 290 * | // | 291 * | | 292 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 293 */ 294 295struct icmp_ext_t { 296 u_int8_t icmp_type; 297 u_int8_t icmp_code; 298 u_int8_t icmp_checksum[2]; 299 u_int8_t icmp_reserved; 300 u_int8_t icmp_length; 301 u_int8_t icmp_reserved2[2]; 302 u_int8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ 303 u_int8_t icmp_ext_version_res[2]; 304 u_int8_t icmp_ext_checksum[2]; 305 u_int8_t icmp_ext_data[1]; 306}; 307 308struct icmp_mpls_ext_object_header_t { 309 u_int8_t length[2]; 310 u_int8_t class_num; 311 u_int8_t ctype; 312}; 313 314static const struct tok icmp_mpls_ext_obj_values[] = { 315 { 1, "MPLS Stack Entry" }, 316 { 2, "Extended Payload" }, 317 { 0, NULL} 318}; 319 320/* prototypes */ 321const char *icmp_tstamp_print(u_int); 322 323/* print the milliseconds since midnight UTC */ 324const char * 325icmp_tstamp_print(u_int tstamp) { 326 u_int msec,sec,min,hrs; 327 328 static char buf[64]; 329 330 msec = tstamp % 1000; 331 sec = tstamp / 1000; 332 min = sec / 60; sec -= min * 60; 333 hrs = min / 60; min -= hrs * 60; 334 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec); 335 return buf; 336} 337 338void 339icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented) 340{ 341 char *cp; 342 const struct icmp *dp; 343 const struct icmp_ext_t *ext_dp; 344 const struct ip *ip; 345 const char *str, *fmt; 346 const struct ip *oip; 347 const struct udphdr *ouh; 348 const u_int8_t *obj_tptr; 349 u_int32_t raw_label; 350 const u_char *snapend_save; 351 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header; 352 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype; 353 char buf[MAXHOSTNAMELEN + 100]; 354 355 dp = (struct icmp *)bp; 356 ext_dp = (struct icmp_ext_t *)bp; 357 ip = (struct ip *)bp2; 358 str = buf; 359 360 TCHECK(dp->icmp_code); 361 switch (dp->icmp_type) { 362 363 case ICMP_ECHO: 364 case ICMP_ECHOREPLY: 365 TCHECK(dp->icmp_seq); 366 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u", 367 dp->icmp_type == ICMP_ECHO ? 368 "request" : "reply", 369 EXTRACT_16BITS(&dp->icmp_id), 370 EXTRACT_16BITS(&dp->icmp_seq)); 371 break; 372 373 case ICMP_UNREACH: 374 TCHECK(dp->icmp_ip.ip_dst); 375 switch (dp->icmp_code) { 376 377 case ICMP_UNREACH_PROTOCOL: 378 TCHECK(dp->icmp_ip.ip_p); 379 (void)snprintf(buf, sizeof(buf), 380 "%s protocol %d unreachable", 381 ipaddr_string(&dp->icmp_ip.ip_dst), 382 dp->icmp_ip.ip_p); 383 break; 384 385 case ICMP_UNREACH_PORT: 386 TCHECK(dp->icmp_ip.ip_p); 387 oip = &dp->icmp_ip; 388 hlen = IP_HL(oip) * 4; 389 ouh = (struct udphdr *)(((u_char *)oip) + hlen); 390 TCHECK(ouh->uh_dport); 391 dport = EXTRACT_16BITS(&ouh->uh_dport); 392 switch (oip->ip_p) { 393 394 case IPPROTO_TCP: 395 (void)snprintf(buf, sizeof(buf), 396 "%s tcp port %s unreachable", 397 ipaddr_string(&oip->ip_dst), 398 tcpport_string(dport)); 399 break; 400 401 case IPPROTO_UDP: 402 (void)snprintf(buf, sizeof(buf), 403 "%s udp port %s unreachable", 404 ipaddr_string(&oip->ip_dst), 405 udpport_string(dport)); 406 break; 407 408 default: 409 (void)snprintf(buf, sizeof(buf), 410 "%s protocol %d port %d unreachable", 411 ipaddr_string(&oip->ip_dst), 412 oip->ip_p, dport); 413 break; 414 } 415 break; 416 417 case ICMP_UNREACH_NEEDFRAG: 418 { 419 register const struct mtu_discovery *mp; 420 mp = (struct mtu_discovery *)(u_char *)&dp->icmp_void; 421 mtu = EXTRACT_16BITS(&mp->nexthopmtu); 422 if (mtu) { 423 (void)snprintf(buf, sizeof(buf), 424 "%s unreachable - need to frag (mtu %d)", 425 ipaddr_string(&dp->icmp_ip.ip_dst), mtu); 426 } else { 427 (void)snprintf(buf, sizeof(buf), 428 "%s unreachable - need to frag", 429 ipaddr_string(&dp->icmp_ip.ip_dst)); 430 } 431 } 432 break; 433 434 default: 435 fmt = tok2str(unreach2str, "#%d %%s unreachable", 436 dp->icmp_code); 437 (void)snprintf(buf, sizeof(buf), fmt, 438 ipaddr_string(&dp->icmp_ip.ip_dst)); 439 break; 440 } 441 break; 442 443 case ICMP_REDIRECT: 444 TCHECK(dp->icmp_ip.ip_dst); 445 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s", 446 dp->icmp_code); 447 (void)snprintf(buf, sizeof(buf), fmt, 448 ipaddr_string(&dp->icmp_ip.ip_dst), 449 ipaddr_string(&dp->icmp_gwaddr)); 450 break; 451 452 case ICMP_ROUTERADVERT: 453 { 454 register const struct ih_rdiscovery *ihp; 455 register const struct id_rdiscovery *idp; 456 u_int lifetime, num, size; 457 458 (void)snprintf(buf, sizeof(buf), "router advertisement"); 459 cp = buf + strlen(buf); 460 461 ihp = (struct ih_rdiscovery *)&dp->icmp_void; 462 TCHECK(*ihp); 463 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); 464 cp = buf + strlen(buf); 465 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime); 466 if (lifetime < 60) { 467 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u", 468 lifetime); 469 } else if (lifetime < 60 * 60) { 470 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u", 471 lifetime / 60, lifetime % 60); 472 } else { 473 (void)snprintf(cp, sizeof(buf) - (cp - buf), 474 "%u:%02u:%02u", 475 lifetime / 3600, 476 (lifetime % 3600) / 60, 477 lifetime % 60); 478 } 479 cp = buf + strlen(buf); 480 481 num = ihp->ird_addrnum; 482 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num); 483 cp = buf + strlen(buf); 484 485 size = ihp->ird_addrsiz; 486 if (size != 2) { 487 (void)snprintf(cp, sizeof(buf) - (cp - buf), 488 " [size %d]", size); 489 break; 490 } 491 idp = (struct id_rdiscovery *)&dp->icmp_data; 492 while (num-- > 0) { 493 TCHECK(*idp); 494 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", 495 ipaddr_string(&idp->ird_addr), 496 EXTRACT_32BITS(&idp->ird_pref)); 497 cp = buf + strlen(buf); 498 ++idp; 499 } 500 } 501 break; 502 503 case ICMP_TIMXCEED: 504 TCHECK(dp->icmp_ip.ip_dst); 505 switch (dp->icmp_code) { 506 507 case ICMP_TIMXCEED_INTRANS: 508 str = "time exceeded in-transit"; 509 break; 510 511 case ICMP_TIMXCEED_REASS: 512 str = "ip reassembly time exceeded"; 513 break; 514 515 default: 516 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d", 517 dp->icmp_code); 518 break; 519 } 520 break; 521 522 case ICMP_PARAMPROB: 523 if (dp->icmp_code) 524 (void)snprintf(buf, sizeof(buf), 525 "parameter problem - code %d", dp->icmp_code); 526 else { 527 TCHECK(dp->icmp_pptr); 528 (void)snprintf(buf, sizeof(buf), 529 "parameter problem - octet %d", dp->icmp_pptr); 530 } 531 break; 532 533 case ICMP_MASKREPLY: 534 TCHECK(dp->icmp_mask); 535 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", 536 EXTRACT_32BITS(&dp->icmp_mask)); 537 break; 538 539 case ICMP_TSTAMP: 540 TCHECK(dp->icmp_seq); 541 (void)snprintf(buf, sizeof(buf), 542 "time stamp query id %u seq %u", 543 EXTRACT_16BITS(&dp->icmp_id), 544 EXTRACT_16BITS(&dp->icmp_seq)); 545 break; 546 547 case ICMP_TSTAMPREPLY: 548 TCHECK(dp->icmp_ttime); 549 (void)snprintf(buf, sizeof(buf), 550 "time stamp reply id %u seq %u: org %s", 551 EXTRACT_16BITS(&dp->icmp_id), 552 EXTRACT_16BITS(&dp->icmp_seq), 553 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime))); 554 555 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", 556 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime))); 557 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", 558 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime))); 559 break; 560 561 default: 562 str = tok2str(icmp2str, "type-#%d", dp->icmp_type); 563 break; 564 } 565 (void)printf("ICMP %s, length %u", str, plen); 566 if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ 567 u_int16_t sum, icmp_sum; 568 if (TTEST2(*bp, plen)) { 569 sum = in_cksum((u_short*)dp, plen, 0); 570 if (sum != 0) { 571 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum); 572 (void)printf(" (wrong icmp cksum %x (->%x)!)", 573 icmp_sum, 574 in_cksum_shouldbe(icmp_sum, sum)); 575 } 576 } 577 } 578 579 /* 580 * print the remnants of the IP packet. 581 * save the snaplength as this may get overidden in the IP printer. 582 */ 583 if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) { 584 bp += 8; 585 (void)printf("\n\t"); 586 ip = (struct ip *)bp; 587 snaplen = snapend - bp; 588 snapend_save = snapend; 589 ip_print(gndo, bp, EXTRACT_16BITS(&ip->ip_len)); 590 snapend = snapend_save; 591 } 592 593 /* 594 * Attempt to decode the MPLS extensions only for some ICMP types. 595 */ 596 if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) { 597 598 TCHECK(*ext_dp); 599 600 /* 601 * Check first if the mpls extension header shows a non-zero length. 602 * If the length field is not set then silently verify the checksum 603 * to check if an extension header is present. This is expedient, 604 * however not all implementations set the length field proper. 605 */ 606 if (!ext_dp->icmp_length && 607 in_cksum((const u_short *)&ext_dp->icmp_ext_version_res, 608 plen - ICMP_EXTD_MINLEN, 0)) { 609 return; 610 } 611 612 printf("\n\tMPLS extension v%u", 613 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); 614 615 /* 616 * Sanity checking of the header. 617 */ 618 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != 619 ICMP_MPLS_EXT_VERSION) { 620 printf(" packet not supported"); 621 return; 622 } 623 624 hlen = plen - ICMP_EXTD_MINLEN; 625 printf(", checksum 0x%04x (%scorrect), length %u", 626 EXTRACT_16BITS(ext_dp->icmp_ext_checksum), 627 in_cksum((const u_short *)&ext_dp->icmp_ext_version_res, 628 plen - ICMP_EXTD_MINLEN, 0) ? "in" : "", 629 hlen); 630 631 hlen -= 4; /* subtract common header size */ 632 obj_tptr = (u_int8_t *)ext_dp->icmp_ext_data; 633 634 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) { 635 636 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr; 637 TCHECK(*icmp_mpls_ext_object_header); 638 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length); 639 obj_class_num = icmp_mpls_ext_object_header->class_num; 640 obj_ctype = icmp_mpls_ext_object_header->ctype; 641 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t); 642 643 printf("\n\t %s Object (%u), Class-Type: %u, length %u", 644 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num), 645 obj_class_num, 646 obj_ctype, 647 obj_tlen); 648 649 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */ 650 651 /* infinite loop protection */ 652 if ((obj_class_num == 0) || 653 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) { 654 return; 655 } 656 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t); 657 658 switch (obj_class_num) { 659 case 1: 660 switch(obj_ctype) { 661 case 1: 662 TCHECK2(*obj_tptr, 4); 663 raw_label = EXTRACT_32BITS(obj_tptr); 664 printf("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)); 665 if (MPLS_STACK(raw_label)) 666 printf(", [S]"); 667 printf(", ttl %u", MPLS_TTL(raw_label)); 668 break; 669 default: 670 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 671 } 672 break; 673 674 /* 675 * FIXME those are the defined objects that lack a decoder 676 * you are welcome to contribute code ;-) 677 */ 678 case 2: 679 default: 680 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 681 break; 682 } 683 if (hlen < obj_tlen) 684 break; 685 hlen -= obj_tlen; 686 obj_tptr += obj_tlen; 687 } 688 } 689 690 return; 691trunc: 692 fputs("[|icmp]", stdout); 693} 694