print-icmp.c revision 1.2.12.1
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 25 static 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 1.2.12.1 2013/06/23 06:28:29 tls 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 */ 58 struct 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 */ 202 static 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 */ 216 static 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 */ 243 static 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 */ 252 struct mtu_discovery { 253 u_int16_t unused; 254 u_int16_t nexthopmtu; 255 }; 256 257 /* rfc1256 */ 258 struct ih_rdiscovery { 259 u_int8_t ird_addrnum; 260 u_int8_t ird_addrsiz; 261 u_int16_t ird_lifetime; 262 }; 263 264 struct 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 */ 294 295 struct 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 }; 307 308 struct icmp_mpls_ext_object_header_t { 309 u_int8_t length[2]; 310 u_int8_t class_num; 311 u_int8_t ctype; 312 }; 313 314 static const struct tok icmp_mpls_ext_obj_values[] = { 315 { 1, "MPLS Stack Entry" }, 316 { 2, "Extended Payload" }, 317 { 0, NULL} 318 }; 319 320 /* prototypes */ 321 const char *icmp_tstamp_print(u_int); 322 323 /* print the milliseconds since midnight UTC */ 324 const char * 325 icmp_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 } 337 338 void 339 icmp_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 struct cksum_vec vec[1]; 355 356 dp = (struct icmp *)bp; 357 ext_dp = (struct icmp_ext_t *)bp; 358 ip = (struct ip *)bp2; 359 str = buf; 360 361 TCHECK(dp->icmp_code); 362 switch (dp->icmp_type) { 363 364 case ICMP_ECHO: 365 case ICMP_ECHOREPLY: 366 TCHECK(dp->icmp_seq); 367 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u", 368 dp->icmp_type == ICMP_ECHO ? 369 "request" : "reply", 370 EXTRACT_16BITS(&dp->icmp_id), 371 EXTRACT_16BITS(&dp->icmp_seq)); 372 break; 373 374 case ICMP_UNREACH: 375 TCHECK(dp->icmp_ip.ip_dst); 376 switch (dp->icmp_code) { 377 378 case ICMP_UNREACH_PROTOCOL: 379 TCHECK(dp->icmp_ip.ip_p); 380 (void)snprintf(buf, sizeof(buf), 381 "%s protocol %d unreachable", 382 ipaddr_string(&dp->icmp_ip.ip_dst), 383 dp->icmp_ip.ip_p); 384 break; 385 386 case ICMP_UNREACH_PORT: 387 TCHECK(dp->icmp_ip.ip_p); 388 oip = &dp->icmp_ip; 389 hlen = IP_HL(oip) * 4; 390 ouh = (struct udphdr *)(((u_char *)oip) + hlen); 391 TCHECK(ouh->uh_dport); 392 dport = EXTRACT_16BITS(&ouh->uh_dport); 393 switch (oip->ip_p) { 394 395 case IPPROTO_TCP: 396 (void)snprintf(buf, sizeof(buf), 397 "%s tcp port %s unreachable", 398 ipaddr_string(&oip->ip_dst), 399 tcpport_string(dport)); 400 break; 401 402 case IPPROTO_UDP: 403 (void)snprintf(buf, sizeof(buf), 404 "%s udp port %s unreachable", 405 ipaddr_string(&oip->ip_dst), 406 udpport_string(dport)); 407 break; 408 409 default: 410 (void)snprintf(buf, sizeof(buf), 411 "%s protocol %d port %d unreachable", 412 ipaddr_string(&oip->ip_dst), 413 oip->ip_p, dport); 414 break; 415 } 416 break; 417 418 case ICMP_UNREACH_NEEDFRAG: 419 { 420 register const struct mtu_discovery *mp; 421 mp = (struct mtu_discovery *)(u_char *)&dp->icmp_void; 422 mtu = EXTRACT_16BITS(&mp->nexthopmtu); 423 if (mtu) { 424 (void)snprintf(buf, sizeof(buf), 425 "%s unreachable - need to frag (mtu %d)", 426 ipaddr_string(&dp->icmp_ip.ip_dst), mtu); 427 } else { 428 (void)snprintf(buf, sizeof(buf), 429 "%s unreachable - need to frag", 430 ipaddr_string(&dp->icmp_ip.ip_dst)); 431 } 432 } 433 break; 434 435 default: 436 fmt = tok2str(unreach2str, "#%d %%s unreachable", 437 dp->icmp_code); 438 (void)snprintf(buf, sizeof(buf), fmt, 439 ipaddr_string(&dp->icmp_ip.ip_dst)); 440 break; 441 } 442 break; 443 444 case ICMP_REDIRECT: 445 TCHECK(dp->icmp_ip.ip_dst); 446 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s", 447 dp->icmp_code); 448 (void)snprintf(buf, sizeof(buf), fmt, 449 ipaddr_string(&dp->icmp_ip.ip_dst), 450 ipaddr_string(&dp->icmp_gwaddr)); 451 break; 452 453 case ICMP_ROUTERADVERT: 454 { 455 register const struct ih_rdiscovery *ihp; 456 register const struct id_rdiscovery *idp; 457 u_int lifetime, num, size; 458 459 (void)snprintf(buf, sizeof(buf), "router advertisement"); 460 cp = buf + strlen(buf); 461 462 ihp = (struct ih_rdiscovery *)&dp->icmp_void; 463 TCHECK(*ihp); 464 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); 465 cp = buf + strlen(buf); 466 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime); 467 if (lifetime < 60) { 468 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u", 469 lifetime); 470 } else if (lifetime < 60 * 60) { 471 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u", 472 lifetime / 60, lifetime % 60); 473 } else { 474 (void)snprintf(cp, sizeof(buf) - (cp - buf), 475 "%u:%02u:%02u", 476 lifetime / 3600, 477 (lifetime % 3600) / 60, 478 lifetime % 60); 479 } 480 cp = buf + strlen(buf); 481 482 num = ihp->ird_addrnum; 483 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num); 484 cp = buf + strlen(buf); 485 486 size = ihp->ird_addrsiz; 487 if (size != 2) { 488 (void)snprintf(cp, sizeof(buf) - (cp - buf), 489 " [size %d]", size); 490 break; 491 } 492 idp = (struct id_rdiscovery *)&dp->icmp_data; 493 while (num-- > 0) { 494 TCHECK(*idp); 495 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", 496 ipaddr_string(&idp->ird_addr), 497 EXTRACT_32BITS(&idp->ird_pref)); 498 cp = buf + strlen(buf); 499 ++idp; 500 } 501 } 502 break; 503 504 case ICMP_TIMXCEED: 505 TCHECK(dp->icmp_ip.ip_dst); 506 switch (dp->icmp_code) { 507 508 case ICMP_TIMXCEED_INTRANS: 509 str = "time exceeded in-transit"; 510 break; 511 512 case ICMP_TIMXCEED_REASS: 513 str = "ip reassembly time exceeded"; 514 break; 515 516 default: 517 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d", 518 dp->icmp_code); 519 break; 520 } 521 break; 522 523 case ICMP_PARAMPROB: 524 if (dp->icmp_code) 525 (void)snprintf(buf, sizeof(buf), 526 "parameter problem - code %d", dp->icmp_code); 527 else { 528 TCHECK(dp->icmp_pptr); 529 (void)snprintf(buf, sizeof(buf), 530 "parameter problem - octet %d", dp->icmp_pptr); 531 } 532 break; 533 534 case ICMP_MASKREPLY: 535 TCHECK(dp->icmp_mask); 536 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", 537 EXTRACT_32BITS(&dp->icmp_mask)); 538 break; 539 540 case ICMP_TSTAMP: 541 TCHECK(dp->icmp_seq); 542 (void)snprintf(buf, sizeof(buf), 543 "time stamp query id %u seq %u", 544 EXTRACT_16BITS(&dp->icmp_id), 545 EXTRACT_16BITS(&dp->icmp_seq)); 546 break; 547 548 case ICMP_TSTAMPREPLY: 549 TCHECK(dp->icmp_ttime); 550 (void)snprintf(buf, sizeof(buf), 551 "time stamp reply id %u seq %u: org %s", 552 EXTRACT_16BITS(&dp->icmp_id), 553 EXTRACT_16BITS(&dp->icmp_seq), 554 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime))); 555 556 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", 557 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime))); 558 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", 559 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime))); 560 break; 561 562 default: 563 str = tok2str(icmp2str, "type-#%d", dp->icmp_type); 564 break; 565 } 566 (void)printf("ICMP %s, length %u", str, plen); 567 if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ 568 u_int16_t sum, icmp_sum; 569 struct cksum_vec vec[1]; 570 if (TTEST2(*bp, plen)) { 571 vec[0].ptr = (const u_int8_t *)(void *)dp; 572 vec[0].len = plen; 573 sum = in_cksum(vec, 1); 574 if (sum != 0) { 575 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum); 576 (void)printf(" (wrong icmp cksum %x (->%x)!)", 577 icmp_sum, 578 in_cksum_shouldbe(icmp_sum, sum)); 579 } 580 } 581 } 582 583 /* 584 * print the remnants of the IP packet. 585 * save the snaplength as this may get overidden in the IP printer. 586 */ 587 if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) { 588 bp += 8; 589 (void)printf("\n\t"); 590 ip = (struct ip *)bp; 591 snaplen = snapend - bp; 592 snapend_save = snapend; 593 ip_print(gndo, bp, EXTRACT_16BITS(&ip->ip_len)); 594 snapend = snapend_save; 595 } 596 597 /* 598 * Attempt to decode the MPLS extensions only for some ICMP types. 599 */ 600 if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) { 601 602 TCHECK(*ext_dp); 603 604 /* 605 * Check first if the mpls extension header shows a non-zero length. 606 * If the length field is not set then silently verify the checksum 607 * to check if an extension header is present. This is expedient, 608 * however not all implementations set the length field proper. 609 */ 610 if (!ext_dp->icmp_length) { 611 vec[0].ptr = (const u_int8_t *)(void *)&ext_dp->icmp_ext_version_res; 612 vec[0].len = plen - ICMP_EXTD_MINLEN; 613 if (in_cksum(vec, 1)) { 614 return; 615 } 616 } 617 618 printf("\n\tMPLS extension v%u", 619 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); 620 621 /* 622 * Sanity checking of the header. 623 */ 624 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != 625 ICMP_MPLS_EXT_VERSION) { 626 printf(" packet not supported"); 627 return; 628 } 629 630 hlen = plen - ICMP_EXTD_MINLEN; 631 vec[0].ptr = (const u_int8_t *)(void *)&ext_dp->icmp_ext_version_res; 632 vec[0].len = hlen; 633 printf(", checksum 0x%04x (%scorrect), length %u", 634 EXTRACT_16BITS(ext_dp->icmp_ext_checksum), 635 in_cksum(vec, 1) ? "in" : "", 636 hlen); 637 638 hlen -= 4; /* subtract common header size */ 639 obj_tptr = (u_int8_t *)ext_dp->icmp_ext_data; 640 641 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) { 642 643 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr; 644 TCHECK(*icmp_mpls_ext_object_header); 645 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length); 646 obj_class_num = icmp_mpls_ext_object_header->class_num; 647 obj_ctype = icmp_mpls_ext_object_header->ctype; 648 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t); 649 650 printf("\n\t %s Object (%u), Class-Type: %u, length %u", 651 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num), 652 obj_class_num, 653 obj_ctype, 654 obj_tlen); 655 656 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */ 657 658 /* infinite loop protection */ 659 if ((obj_class_num == 0) || 660 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) { 661 return; 662 } 663 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t); 664 665 switch (obj_class_num) { 666 case 1: 667 switch(obj_ctype) { 668 case 1: 669 TCHECK2(*obj_tptr, 4); 670 raw_label = EXTRACT_32BITS(obj_tptr); 671 printf("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)); 672 if (MPLS_STACK(raw_label)) 673 printf(", [S]"); 674 printf(", ttl %u", MPLS_TTL(raw_label)); 675 break; 676 default: 677 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 678 } 679 break; 680 681 /* 682 * FIXME those are the defined objects that lack a decoder 683 * you are welcome to contribute code ;-) 684 */ 685 case 2: 686 default: 687 print_unknown_data(obj_tptr, "\n\t ", obj_tlen); 688 break; 689 } 690 if (hlen < obj_tlen) 691 break; 692 hlen -= obj_tlen; 693 obj_tptr += obj_tlen; 694 } 695 } 696 697 return; 698 trunc: 699 fputs("[|icmp]", stdout); 700 } 701
Indexes created Mon Jun 29 00:24:49 UTC 2026