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 1.81.2.6 2007/09/13 17:40:18 guy 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 } icmp_hun; 68 #define icmp_pptr icmp_hun.ih_pptr 69 #define icmp_gwaddr icmp_hun.ih_gwaddr 70 #define icmp_id icmp_hun.ih_idseq.icd_id 71 #define icmp_seq icmp_hun.ih_idseq.icd_seq 72 #define icmp_void icmp_hun.ih_void 73 union { 74 struct id_ts { 75 u_int32_t its_otime; 76 u_int32_t its_rtime; 77 u_int32_t its_ttime; 78 } id_ts; 79 struct id_ip { 80 struct ip idi_ip; 81 /* options and then 64 bits of data */ 82 } id_ip; 83 u_int32_t id_mask; 84 u_int8_t id_data[1]; 85 } icmp_dun; 86 #define icmp_otime icmp_dun.id_ts.its_otime 87 #define icmp_rtime icmp_dun.id_ts.its_rtime 88 #define icmp_ttime icmp_dun.id_ts.its_ttime 89 #define icmp_ip icmp_dun.id_ip.idi_ip 90 #define icmp_mask icmp_dun.id_mask 91 #define icmp_data icmp_dun.id_data 92 }; 93 94 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) 95 #define ICMP_MPLS_EXT_VERSION 2 96 97 /* 98 * Lower bounds on packet lengths for various types. 99 * For the error advice packets must first insure that the 100 * packet is large enought to contain the returned ip header. 101 * Only then can we do the check to see if 64 bits of packet 102 * data have been returned, since we need to check the returned 103 * ip header length. 104 */ 105 #define ICMP_MINLEN 8 /* abs minimum */ 106 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */ 107 #define ICMP_TSLEN (8 + 3 * sizeof (u_int32_t)) /* timestamp */ 108 #define ICMP_MASKLEN 12 /* address mask */ 109 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */ 110 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8) 111 /* N.B.: must separately check that ip_hl >= 5 */ 112 113 /* 114 * Definition of type and code field values. 115 */ 116 #define ICMP_ECHOREPLY 0 /* echo reply */ 117 #define ICMP_UNREACH 3 /* dest unreachable, codes: */ 118 #define ICMP_UNREACH_NET 0 /* bad net */ 119 #define ICMP_UNREACH_HOST 1 /* bad host */ 120 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */ 121 #define ICMP_UNREACH_PORT 3 /* bad port */ 122 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */ 123 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */ 124 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */ 125 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */ 126 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */ 127 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */ 128 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */ 129 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */ 130 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */ 131 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */ 132 #define ICMP_REDIRECT 5 /* shorter route, codes: */ 133 #define ICMP_REDIRECT_NET 0 /* for network */ 134 #define ICMP_REDIRECT_HOST 1 /* for host */ 135 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */ 136 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */ 137 #define ICMP_ECHO 8 /* echo service */ 138 #define ICMP_ROUTERADVERT 9 /* router advertisement */ 139 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */ 140 #define ICMP_TIMXCEED 11 /* time exceeded, code: */ 141 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */ 142 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */ 143 #define ICMP_PARAMPROB 12 /* ip header bad */ 144 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */ 145 #define ICMP_TSTAMP 13 /* timestamp request */ 146 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */ 147 #define ICMP_IREQ 15 /* information request */ 148 #define ICMP_IREQREPLY 16 /* information reply */ 149 #define ICMP_MASKREQ 17 /* address mask request */ 150 #define ICMP_MASKREPLY 18 /* address mask reply */ 151 152 #define ICMP_MAXTYPE 18 153 154 #define ICMP_INFOTYPE(type) \ 155 ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \ 156 (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \ 157 (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \ 158 (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \ 159 (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY) 160 #define ICMP_MPLS_EXT_TYPE(type) \ 161 ((type) == ICMP_UNREACH || \ 162 (type) == ICMP_TIMXCEED || \ 163 (type) == ICMP_PARAMPROB) 164 /* rfc1700 */ 165 #ifndef ICMP_UNREACH_NET_UNKNOWN 166 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */ 167 #endif 168 #ifndef ICMP_UNREACH_HOST_UNKNOWN 169 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */ 170 #endif 171 #ifndef ICMP_UNREACH_ISOLATED 172 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */ 173 #endif 174 #ifndef ICMP_UNREACH_NET_PROHIB 175 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */ 176 #endif 177 #ifndef ICMP_UNREACH_HOST_PROHIB 178 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */ 179 #endif 180 #ifndef ICMP_UNREACH_TOSNET 181 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */ 182 #endif 183 #ifndef ICMP_UNREACH_TOSHOST 184 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */ 185 #endif 186 187 /* rfc1716 */ 188 #ifndef ICMP_UNREACH_FILTER_PROHIB 189 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */ 190 #endif 191 #ifndef ICMP_UNREACH_HOST_PRECEDENCE 192 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */ 193 #endif 194 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF 195 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */ 196 #endif 197 198 /* Most of the icmp types */ 199 static struct tok icmp2str[] = { 200 { ICMP_ECHOREPLY, "echo reply" }, 201 { ICMP_SOURCEQUENCH, "source quench" }, 202 { ICMP_ECHO, "echo request" }, 203 { ICMP_ROUTERSOLICIT, "router solicitation" }, 204 { ICMP_TSTAMP, "time stamp request" }, 205 { ICMP_TSTAMPREPLY, "time stamp reply" }, 206 { ICMP_IREQ, "information request" }, 207 { ICMP_IREQREPLY, "information reply" }, 208 { ICMP_MASKREQ, "address mask request" }, 209 { 0, NULL } 210 }; 211 212 /* Formats for most of the ICMP_UNREACH codes */ 213 static struct tok unreach2str[] = { 214 { ICMP_UNREACH_NET, "net %s unreachable" }, 215 { ICMP_UNREACH_HOST, "host %s unreachable" }, 216 { ICMP_UNREACH_SRCFAIL, 217 "%s unreachable - source route failed" }, 218 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" }, 219 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" }, 220 { ICMP_UNREACH_ISOLATED, 221 "%s unreachable - source host isolated" }, 222 { ICMP_UNREACH_NET_PROHIB, 223 "net %s unreachable - admin prohibited" }, 224 { ICMP_UNREACH_HOST_PROHIB, 225 "host %s unreachable - admin prohibited" }, 226 { ICMP_UNREACH_TOSNET, 227 "net %s unreachable - tos prohibited" }, 228 { ICMP_UNREACH_TOSHOST, 229 "host %s unreachable - tos prohibited" }, 230 { ICMP_UNREACH_FILTER_PROHIB, 231 "host %s unreachable - admin prohibited filter" }, 232 { ICMP_UNREACH_HOST_PRECEDENCE, 233 "host %s unreachable - host precedence violation" }, 234 { ICMP_UNREACH_PRECEDENCE_CUTOFF, 235 "host %s unreachable - precedence cutoff" }, 236 { 0, NULL } 237 }; 238 239 /* Formats for the ICMP_REDIRECT codes */ 240 static struct tok type2str[] = { 241 { ICMP_REDIRECT_NET, "redirect %s to net %s" }, 242 { ICMP_REDIRECT_HOST, "redirect %s to host %s" }, 243 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" }, 244 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" }, 245 { 0, NULL } 246 }; 247 248 /* rfc1191 */ 249 struct mtu_discovery { 250 u_int16_t unused; 251 u_int16_t nexthopmtu; 252 }; 253 254 /* rfc1256 */ 255 struct ih_rdiscovery { 256 u_int8_t ird_addrnum; 257 u_int8_t ird_addrsiz; 258 u_int16_t ird_lifetime; 259 }; 260 261 struct id_rdiscovery { 262 u_int32_t ird_addr; 263 u_int32_t ird_pref; 264 }; 265 266 /* 267 * draft-bonica-internet-icmp-08 268 * 269 * The Destination Unreachable, Time Exceeded 270 * and Parameter Problem messages are slighly changed as per 271 * the above draft. A new Length field gets added to give 272 * the caller an idea about the length of the piggypacked 273 * IP packet before the MPLS extension header starts. 274 * 275 * The Length field represents length of the padded "original datagram" 276 * field measured in 32-bit words. 277 * 278 * 0 1 2 3 279 * 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 1 280 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 281 * | Type | Code | Checksum | 282 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 283 * | unused | Length | unused | 284 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 285 * | Internet Header + leading octets of original datagram | 286 * | | 287 * | // | 288 * | | 289 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 290 */ 291 292 struct icmp_ext_t { 293 u_int8_t icmp_type; 294 u_int8_t icmp_code; 295 u_int8_t icmp_checksum[2]; 296 u_int8_t icmp_reserved; 297 u_int8_t icmp_length; 298 u_int8_t icmp_reserved2[2]; 299 u_int8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ 300 u_int8_t icmp_ext_version_res[2]; 301 u_int8_t icmp_ext_checksum[2]; 302 u_int8_t icmp_ext_data[1]; 303 }; 304 305 struct icmp_mpls_ext_object_header_t { 306 u_int8_t length[2]; 307 u_int8_t class_num; 308 u_int8_t ctype; 309 }; 310 311 static const struct tok icmp_mpls_ext_obj_values[] = { 312 { 1, "MPLS Stack Entry" }, 313 { 2, "Extended Payload" }, 314 { 0, NULL} 315 }; 316 317 /* prototypes */ 318 const char *icmp_tstamp_print(u_int); 319 320 /* print the milliseconds since midnight UTC */ 321 const char * 322 icmp_tstamp_print(u_int tstamp) { 323 u_int msec,sec,min,hrs; 324 325 static char buf[64]; 326 327 msec = tstamp % 1000; 328 sec = tstamp / 1000; 329 min = sec / 60; sec -= min * 60; 330 hrs = min / 60; min -= hrs * 60; 331 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec); 332 return buf; 333 } 334 335 void 336 icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented) 337 { 338 char *cp; 339 const struct icmp *dp; 340 const struct icmp_ext_t *ext_dp; 341 const struct ip *ip; 342 const char *str, *fmt; 343 const struct ip *oip; 344 const struct udphdr *ouh; 345 const u_int8_t *obj_tptr; 346 u_int32_t raw_label; 347 const u_char *snapend_save; 348 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header; 349 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype; 350 char buf[MAXHOSTNAMELEN + 100]; 351 352 dp = (struct icmp *)bp; 353 ext_dp = (struct icmp_ext_t *)bp; 354 ip = (struct ip *)bp2; 355 str = buf; 356 357 TCHECK(dp->icmp_code); 358 switch (dp->icmp_type) { 359 360 case ICMP_ECHO: 361 case ICMP_ECHOREPLY: 362 TCHECK(dp->icmp_seq); 363 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u", 364 dp->icmp_type == ICMP_ECHO ? 365 "request" : "reply", 366 EXTRACT_16BITS(&dp->icmp_id), 367 EXTRACT_16BITS(&dp->icmp_seq)); 368 break; 369 370 case ICMP_UNREACH: 371 TCHECK(dp->icmp_ip.ip_dst); 372 switch (dp->icmp_code) { 373 374 case ICMP_UNREACH_PROTOCOL: 375 TCHECK(dp->icmp_ip.ip_p); 376 (void)snprintf(buf, sizeof(buf), 377 "%s protocol %d unreachable", 378 ipaddr_string(&dp->icmp_ip.ip_dst), 379 dp->icmp_ip.ip_p); 380 break; 381 382 case ICMP_UNREACH_PORT: 383 TCHECK(dp->icmp_ip.ip_p); 384 oip = &dp->icmp_ip; 385 hlen = IP_HL(oip) * 4; 386 ouh = (struct udphdr *)(((u_char *)oip) + hlen); 387 TCHECK(ouh->uh_dport); 388 dport = EXTRACT_16BITS(&ouh->uh_dport); 389 switch (oip->ip_p) { 390 391 case IPPROTO_TCP: 392 (void)snprintf(buf, sizeof(buf), 393 "%s tcp port %s unreachable", 394 ipaddr_string(&oip->ip_dst), 395 tcpport_string(dport)); 396 break; 397 398 case IPPROTO_UDP: 399 (void)snprintf(buf, sizeof(buf), 400 "%s udp port %s unreachable", 401 ipaddr_string(&oip->ip_dst), 402 udpport_string(dport)); 403 break; 404 405 default: 406 (void)snprintf(buf, sizeof(buf), 407 "%s protocol %d port %d unreachable", 408 ipaddr_string(&oip->ip_dst), 409 oip->ip_p, dport); 410 break; 411 } 412 break; 413 414 case ICMP_UNREACH_NEEDFRAG: 415 { 416 register const struct mtu_discovery *mp; 417 mp = (struct mtu_discovery *)&dp->icmp_void; 418 mtu = EXTRACT_16BITS(&mp->nexthopmtu); 419 if (mtu) { 420 (void)snprintf(buf, sizeof(buf), 421 "%s unreachable - need to frag (mtu %d)", 422 ipaddr_string(&dp->icmp_ip.ip_dst), mtu); 423 } else { 424 (void)snprintf(buf, sizeof(buf), 425 "%s unreachable - need to frag", 426 ipaddr_string(&dp->icmp_ip.ip_dst)); 427 } 428 } 429 break; 430 431 default: 432 fmt = tok2str(unreach2str, "#%d %%s unreachable", 433 dp->icmp_code); 434 (void)snprintf(buf, sizeof(buf), fmt, 435 ipaddr_string(&dp->icmp_ip.ip_dst)); 436 break; 437 } 438 break; 439 440 case ICMP_REDIRECT: 441 TCHECK(dp->icmp_ip.ip_dst); 442 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s", 443 dp->icmp_code); 444 (void)snprintf(buf, sizeof(buf), fmt, 445 ipaddr_string(&dp->icmp_ip.ip_dst), 446 ipaddr_string(&dp->icmp_gwaddr)); 447 break; 448 449 case ICMP_ROUTERADVERT: 450 { 451 register const struct ih_rdiscovery *ihp; 452 register const struct id_rdiscovery *idp; 453 u_int lifetime, num, size; 454 455 (void)snprintf(buf, sizeof(buf), "router advertisement"); 456 cp = buf + strlen(buf); 457 458 ihp = (struct ih_rdiscovery *)&dp->icmp_void; 459 TCHECK(*ihp); 460 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); 461 cp = buf + strlen(buf); 462 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime); 463 if (lifetime < 60) { 464 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u", 465 lifetime); 466 } else if (lifetime < 60 * 60) { 467 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u", 468 lifetime / 60, lifetime % 60); 469 } else { 470 (void)snprintf(cp, sizeof(buf) - (cp - buf), 471 "%u:%02u:%02u", 472 lifetime / 3600, 473 (lifetime % 3600) / 60, 474 lifetime % 60); 475 } 476 cp = buf + strlen(buf); 477 478 num = ihp->ird_addrnum; 479 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num); 480 cp = buf + strlen(buf); 481 482 size = ihp->ird_addrsiz; 483 if (size != 2) { 484 (void)snprintf(cp, sizeof(buf) - (cp - buf), 485 " [size %d]", size); 486 break; 487 } 488 idp = (struct id_rdiscovery *)&dp->icmp_data; 489 while (num-- > 0) { 490 TCHECK(*idp); 491 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", 492 ipaddr_string(&idp->ird_addr), 493 EXTRACT_32BITS(&idp->ird_pref)); 494 cp = buf + strlen(buf); 495 ++idp; 496 } 497 } 498 break; 499 500 case ICMP_TIMXCEED: 501 TCHECK(dp->icmp_ip.ip_dst); 502 switch (dp->icmp_code) { 503 504 case ICMP_TIMXCEED_INTRANS: 505 str = "time exceeded in-transit"; 506 break; 507 508 case ICMP_TIMXCEED_REASS: 509 str = "ip reassembly time exceeded"; 510 break; 511 512 default: 513 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d", 514 dp->icmp_code); 515 break; 516 } 517 break; 518 519 case ICMP_PARAMPROB: 520 if (dp->icmp_code) 521 (void)snprintf(buf, sizeof(buf), 522 "parameter problem - code %d", dp->icmp_code); 523 else { 524 TCHECK(dp->icmp_pptr); 525 (void)snprintf(buf, sizeof(buf), 526 "parameter problem - octet %d", dp->icmp_pptr); 527 } 528 break; 529 530 case ICMP_MASKREPLY: 531 TCHECK(dp->icmp_mask); 532 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", 533 EXTRACT_32BITS(&dp->icmp_mask)); 534 break; 535 536 case ICMP_TSTAMP: 537 TCHECK(dp->icmp_seq); 538 (void)snprintf(buf, sizeof(buf), 539 "time stamp query id %u seq %u", 540 EXTRACT_16BITS(&dp->icmp_id), 541 EXTRACT_16BITS(&dp->icmp_seq)); 542 break; 543 544 case ICMP_TSTAMPREPLY: 545 TCHECK(dp->icmp_ttime); 546 (void)snprintf(buf, sizeof(buf), 547 "time stamp reply id %u seq %u: org %s", 548 EXTRACT_16BITS(&dp->icmp_id), 549 EXTRACT_16BITS(&dp->icmp_seq), 550 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime))); 551 552 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", 553 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime))); 554 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", 555 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime))); 556 break; 557 558 default: 559 str = tok2str(icmp2str, "type-#%d", dp->icmp_type); 560 break; 561 } 562 (void)printf("ICMP %s, length %u", str, plen); 563 if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ 564 u_int16_t sum, icmp_sum; 565 if (TTEST2(*bp, plen)) { 566 sum = in_cksum((u_short*)dp, plen, 0); 567 if (sum != 0) { 568 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum); 569 (void)printf(" (wrong icmp cksum %x (->%x)!)", 570 icmp_sum, 571 in_cksum_shouldbe(icmp_sum, sum)); 572 } 573 } 574 } 575 576 /* 577 * print the remnants of the IP packet. 578 * save the snaplength as this may get overidden in the IP printer. 579 */ 580 if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) { 581 bp += 8; 582 (void)printf("\n\t"); 583 ip = (struct ip *)bp; 584 snaplen = snapend - bp; 585 snapend_save = snapend; 586 ip_print(gndo, bp, EXTRACT_16BITS(&ip->ip_len)); 587 snapend = snapend_save; 588 } 589 590 /* 591 * Attempt to decode the MPLS extensions only for some ICMP types. 592 */ 593 if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) { 594 595 TCHECK(*ext_dp); 596 597 /* 598 * Check first if the mpls extension header shows a non-zero length. 599 * If the length field is not set then silently verify the checksum 600 * to check if an extension header is present. This is expedient, 601 * however not all implementations set the length field proper. 602 */ 603 if (!ext_dp->icmp_length && 604 in_cksum((const u_short *)&ext_dp->icmp_ext_version_res, 605 plen - ICMP_EXTD_MINLEN, 0)) { 606 return; 607 } 608 609 printf("\n\tMPLS extension v%u", 610 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); 611 612 /* 613 * Sanity checking of the header. 614 */ 615 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != 616 ICMP_MPLS_EXT_VERSION) { 617 printf(" packet not supported"); 618 return; 619 } 620 621 hlen = plen - ICMP_EXTD_MINLEN; 622 printf(", checksum 0x%04x (%scorrect), length %u", 623 EXTRACT_16BITS(ext_dp->icmp_ext_checksum), 624 in_cksum((const u_short *)&ext_dp->icmp_ext_version_res, 625 plen - ICMP_EXTD_MINLEN, 0) ? "in" : "", 626 hlen); 627 628 hlen -= 4; /* subtract common header size */ 629 obj_tptr = (u_int8_t *)ext_dp->icmp_ext_data; 630 631 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) { 632 633 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr; 634 TCHECK(*icmp_mpls_ext_object_header); 635 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length); 636 obj_class_num = icmp_mpls_ext_object_header->class_num; 637 obj_ctype = icmp_mpls_ext_object_header->ctype; 638 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t); 639 640 printf("\n\t %s Object (%u), Class-Type: %u, length %u", 641 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num), 642 obj_class_num, 643 obj_ctype, 644 obj_tlen); 645 646 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */ 647 648 /* infinite loop protection */ 649 if ((obj_class_num == 0) || 650 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) { 651 return; 652 } 653 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t); 654 655 switch (obj_class_num) { 656 case 1: 657 switch(obj_ctype) { 658 case 1: 659 TCHECK2(*obj_tptr, 4); 660 raw_label = EXTRACT_32BITS(obj_tptr); 661 printf("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)); 662 if (MPLS_STACK(raw_label)) 663 printf(", [S]"); 664 printf(", ttl %u", MPLS_TTL(raw_label)); 665 break; 666 default: 667 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 668 } 669 break; 670 671 /* 672 * FIXME those are the defined objects that lack a decoder 673 * you are welcome to contribute code ;-) 674 */ 675 case 2: 676 default: 677 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 678 break; 679 } 680 if (hlen < obj_tlen) 681 break; 682 hlen -= obj_tlen; 683 obj_tptr += obj_tlen; 684 } 685 } 686 687 return; 688 trunc: 689 fputs("[|icmp]", stdout); 690 } 691