print-icmp.c revision 1.1.1.6
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 #ifdef HAVE_CONFIG_H 23 #include "config.h" 24 #endif 25 26 #include <netdissect-stdinc.h> 27 28 #include <stdio.h> 29 #include <string.h> 30 31 #include "netdissect.h" 32 #include "addrtoname.h" 33 #include "extract.h" 34 35 #include "ip.h" 36 #include "udp.h" 37 #include "ipproto.h" 38 #include "mpls.h" 39 40 /* 41 * Interface Control Message Protocol Definitions. 42 * Per RFC 792, September 1981. 43 */ 44 45 /* 46 * Structure of an icmp header. 47 */ 48 struct icmp { 49 uint8_t icmp_type; /* type of message, see below */ 50 uint8_t icmp_code; /* type sub code */ 51 uint16_t icmp_cksum; /* ones complement cksum of struct */ 52 union { 53 uint8_t ih_pptr; /* ICMP_PARAMPROB */ 54 struct in_addr ih_gwaddr; /* ICMP_REDIRECT */ 55 struct ih_idseq { 56 uint16_t icd_id; 57 uint16_t icd_seq; 58 } ih_idseq; 59 uint32_t ih_void; 60 } icmp_hun; 61 #define icmp_pptr icmp_hun.ih_pptr 62 #define icmp_gwaddr icmp_hun.ih_gwaddr 63 #define icmp_id icmp_hun.ih_idseq.icd_id 64 #define icmp_seq icmp_hun.ih_idseq.icd_seq 65 #define icmp_void icmp_hun.ih_void 66 union { 67 struct id_ts { 68 uint32_t its_otime; 69 uint32_t its_rtime; 70 uint32_t its_ttime; 71 } id_ts; 72 struct id_ip { 73 struct ip idi_ip; 74 /* options and then 64 bits of data */ 75 } id_ip; 76 uint32_t id_mask; 77 uint8_t id_data[1]; 78 } icmp_dun; 79 #define icmp_otime icmp_dun.id_ts.its_otime 80 #define icmp_rtime icmp_dun.id_ts.its_rtime 81 #define icmp_ttime icmp_dun.id_ts.its_ttime 82 #define icmp_ip icmp_dun.id_ip.idi_ip 83 #define icmp_mask icmp_dun.id_mask 84 #define icmp_data icmp_dun.id_data 85 }; 86 87 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) 88 #define ICMP_MPLS_EXT_VERSION 2 89 90 /* 91 * Lower bounds on packet lengths for various types. 92 * For the error advice packets must first insure that the 93 * packet is large enought to contain the returned ip header. 94 * Only then can we do the check to see if 64 bits of packet 95 * data have been returned, since we need to check the returned 96 * ip header length. 97 */ 98 #define ICMP_MINLEN 8 /* abs minimum */ 99 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */ 100 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */ 101 #define ICMP_MASKLEN 12 /* address mask */ 102 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */ 103 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8) 104 /* N.B.: must separately check that ip_hl >= 5 */ 105 106 /* 107 * Definition of type and code field values. 108 */ 109 #define ICMP_ECHOREPLY 0 /* echo reply */ 110 #define ICMP_UNREACH 3 /* dest unreachable, codes: */ 111 #define ICMP_UNREACH_NET 0 /* bad net */ 112 #define ICMP_UNREACH_HOST 1 /* bad host */ 113 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */ 114 #define ICMP_UNREACH_PORT 3 /* bad port */ 115 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */ 116 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */ 117 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */ 118 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */ 119 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */ 120 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */ 121 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */ 122 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */ 123 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */ 124 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */ 125 #define ICMP_REDIRECT 5 /* shorter route, codes: */ 126 #define ICMP_REDIRECT_NET 0 /* for network */ 127 #define ICMP_REDIRECT_HOST 1 /* for host */ 128 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */ 129 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */ 130 #define ICMP_ECHO 8 /* echo service */ 131 #define ICMP_ROUTERADVERT 9 /* router advertisement */ 132 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */ 133 #define ICMP_TIMXCEED 11 /* time exceeded, code: */ 134 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */ 135 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */ 136 #define ICMP_PARAMPROB 12 /* ip header bad */ 137 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */ 138 #define ICMP_TSTAMP 13 /* timestamp request */ 139 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */ 140 #define ICMP_IREQ 15 /* information request */ 141 #define ICMP_IREQREPLY 16 /* information reply */ 142 #define ICMP_MASKREQ 17 /* address mask request */ 143 #define ICMP_MASKREPLY 18 /* address mask reply */ 144 145 #define ICMP_MAXTYPE 18 146 147 #define ICMP_ERRTYPE(type) \ 148 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \ 149 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \ 150 (type) == ICMP_PARAMPROB) 151 #define ICMP_MPLS_EXT_TYPE(type) \ 152 ((type) == ICMP_UNREACH || \ 153 (type) == ICMP_TIMXCEED || \ 154 (type) == ICMP_PARAMPROB) 155 /* rfc1700 */ 156 #ifndef ICMP_UNREACH_NET_UNKNOWN 157 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */ 158 #endif 159 #ifndef ICMP_UNREACH_HOST_UNKNOWN 160 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */ 161 #endif 162 #ifndef ICMP_UNREACH_ISOLATED 163 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */ 164 #endif 165 #ifndef ICMP_UNREACH_NET_PROHIB 166 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */ 167 #endif 168 #ifndef ICMP_UNREACH_HOST_PROHIB 169 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */ 170 #endif 171 #ifndef ICMP_UNREACH_TOSNET 172 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */ 173 #endif 174 #ifndef ICMP_UNREACH_TOSHOST 175 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */ 176 #endif 177 178 /* rfc1716 */ 179 #ifndef ICMP_UNREACH_FILTER_PROHIB 180 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */ 181 #endif 182 #ifndef ICMP_UNREACH_HOST_PRECEDENCE 183 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */ 184 #endif 185 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF 186 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */ 187 #endif 188 189 /* Most of the icmp types */ 190 static const struct tok icmp2str[] = { 191 { ICMP_ECHOREPLY, "echo reply" }, 192 { ICMP_SOURCEQUENCH, "source quench" }, 193 { ICMP_ECHO, "echo request" }, 194 { ICMP_ROUTERSOLICIT, "router solicitation" }, 195 { ICMP_TSTAMP, "time stamp request" }, 196 { ICMP_TSTAMPREPLY, "time stamp reply" }, 197 { ICMP_IREQ, "information request" }, 198 { ICMP_IREQREPLY, "information reply" }, 199 { ICMP_MASKREQ, "address mask request" }, 200 { 0, NULL } 201 }; 202 203 /* Formats for most of the ICMP_UNREACH codes */ 204 static const struct tok unreach2str[] = { 205 { ICMP_UNREACH_NET, "net %s unreachable" }, 206 { ICMP_UNREACH_HOST, "host %s unreachable" }, 207 { ICMP_UNREACH_SRCFAIL, 208 "%s unreachable - source route failed" }, 209 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" }, 210 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" }, 211 { ICMP_UNREACH_ISOLATED, 212 "%s unreachable - source host isolated" }, 213 { ICMP_UNREACH_NET_PROHIB, 214 "net %s unreachable - admin prohibited" }, 215 { ICMP_UNREACH_HOST_PROHIB, 216 "host %s unreachable - admin prohibited" }, 217 { ICMP_UNREACH_TOSNET, 218 "net %s unreachable - tos prohibited" }, 219 { ICMP_UNREACH_TOSHOST, 220 "host %s unreachable - tos prohibited" }, 221 { ICMP_UNREACH_FILTER_PROHIB, 222 "host %s unreachable - admin prohibited filter" }, 223 { ICMP_UNREACH_HOST_PRECEDENCE, 224 "host %s unreachable - host precedence violation" }, 225 { ICMP_UNREACH_PRECEDENCE_CUTOFF, 226 "host %s unreachable - precedence cutoff" }, 227 { 0, NULL } 228 }; 229 230 /* Formats for the ICMP_REDIRECT codes */ 231 static const struct tok type2str[] = { 232 { ICMP_REDIRECT_NET, "redirect %s to net %s" }, 233 { ICMP_REDIRECT_HOST, "redirect %s to host %s" }, 234 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" }, 235 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" }, 236 { 0, NULL } 237 }; 238 239 /* rfc1191 */ 240 struct mtu_discovery { 241 uint16_t unused; 242 uint16_t nexthopmtu; 243 }; 244 245 /* rfc1256 */ 246 struct ih_rdiscovery { 247 uint8_t ird_addrnum; 248 uint8_t ird_addrsiz; 249 uint16_t ird_lifetime; 250 }; 251 252 struct id_rdiscovery { 253 uint32_t ird_addr; 254 uint32_t ird_pref; 255 }; 256 257 /* 258 * draft-bonica-internet-icmp-08 259 * 260 * The Destination Unreachable, Time Exceeded 261 * and Parameter Problem messages are slighly changed as per 262 * the above draft. A new Length field gets added to give 263 * the caller an idea about the length of the piggypacked 264 * IP packet before the MPLS extension header starts. 265 * 266 * The Length field represents length of the padded "original datagram" 267 * field measured in 32-bit words. 268 * 269 * 0 1 2 3 270 * 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 1 271 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 272 * | Type | Code | Checksum | 273 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 274 * | unused | Length | unused | 275 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 276 * | Internet Header + leading octets of original datagram | 277 * | | 278 * | // | 279 * | | 280 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 281 */ 282 283 struct icmp_ext_t { 284 uint8_t icmp_type; 285 uint8_t icmp_code; 286 uint8_t icmp_checksum[2]; 287 uint8_t icmp_reserved; 288 uint8_t icmp_length; 289 uint8_t icmp_reserved2[2]; 290 uint8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ 291 uint8_t icmp_ext_version_res[2]; 292 uint8_t icmp_ext_checksum[2]; 293 uint8_t icmp_ext_data[1]; 294 }; 295 296 struct icmp_mpls_ext_object_header_t { 297 uint8_t length[2]; 298 uint8_t class_num; 299 uint8_t ctype; 300 }; 301 302 static const struct tok icmp_mpls_ext_obj_values[] = { 303 { 1, "MPLS Stack Entry" }, 304 { 2, "Extended Payload" }, 305 { 0, NULL} 306 }; 307 308 /* prototypes */ 309 const char *icmp_tstamp_print(u_int); 310 311 /* print the milliseconds since midnight UTC */ 312 const char * 313 icmp_tstamp_print(u_int tstamp) 314 { 315 u_int msec,sec,min,hrs; 316 317 static char buf[64]; 318 319 msec = tstamp % 1000; 320 sec = tstamp / 1000; 321 min = sec / 60; sec -= min * 60; 322 hrs = min / 60; min -= hrs * 60; 323 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec); 324 return buf; 325 } 326 327 void 328 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2, 329 int fragmented) 330 { 331 char *cp; 332 const struct icmp *dp; 333 const struct icmp_ext_t *ext_dp; 334 const struct ip *ip; 335 const char *str, *fmt; 336 const struct ip *oip; 337 const struct udphdr *ouh; 338 const uint8_t *obj_tptr; 339 uint32_t raw_label; 340 const u_char *snapend_save; 341 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header; 342 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype; 343 char buf[MAXHOSTNAMELEN + 100]; 344 struct cksum_vec vec[1]; 345 346 dp = (const struct icmp *)bp; 347 ext_dp = (const struct icmp_ext_t *)bp; 348 ip = (const struct ip *)bp2; 349 str = buf; 350 351 ND_TCHECK(dp->icmp_code); 352 switch (dp->icmp_type) { 353 354 case ICMP_ECHO: 355 case ICMP_ECHOREPLY: 356 ND_TCHECK(dp->icmp_seq); 357 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u", 358 dp->icmp_type == ICMP_ECHO ? 359 "request" : "reply", 360 EXTRACT_16BITS(&dp->icmp_id), 361 EXTRACT_16BITS(&dp->icmp_seq)); 362 break; 363 364 case ICMP_UNREACH: 365 ND_TCHECK(dp->icmp_ip.ip_dst); 366 switch (dp->icmp_code) { 367 368 case ICMP_UNREACH_PROTOCOL: 369 ND_TCHECK(dp->icmp_ip.ip_p); 370 (void)snprintf(buf, sizeof(buf), 371 "%s protocol %d unreachable", 372 ipaddr_string(ndo, &dp->icmp_ip.ip_dst), 373 dp->icmp_ip.ip_p); 374 break; 375 376 case ICMP_UNREACH_PORT: 377 ND_TCHECK(dp->icmp_ip.ip_p); 378 oip = &dp->icmp_ip; 379 hlen = IP_HL(oip) * 4; 380 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen); 381 ND_TCHECK(ouh->uh_dport); 382 dport = EXTRACT_16BITS(&ouh->uh_dport); 383 switch (oip->ip_p) { 384 385 case IPPROTO_TCP: 386 (void)snprintf(buf, sizeof(buf), 387 "%s tcp port %s unreachable", 388 ipaddr_string(ndo, &oip->ip_dst), 389 tcpport_string(ndo, dport)); 390 break; 391 392 case IPPROTO_UDP: 393 (void)snprintf(buf, sizeof(buf), 394 "%s udp port %s unreachable", 395 ipaddr_string(ndo, &oip->ip_dst), 396 udpport_string(ndo, dport)); 397 break; 398 399 default: 400 (void)snprintf(buf, sizeof(buf), 401 "%s protocol %d port %d unreachable", 402 ipaddr_string(ndo, &oip->ip_dst), 403 oip->ip_p, dport); 404 break; 405 } 406 break; 407 408 case ICMP_UNREACH_NEEDFRAG: 409 { 410 register const struct mtu_discovery *mp; 411 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void; 412 mtu = EXTRACT_16BITS(&mp->nexthopmtu); 413 if (mtu) { 414 (void)snprintf(buf, sizeof(buf), 415 "%s unreachable - need to frag (mtu %d)", 416 ipaddr_string(ndo, &dp->icmp_ip.ip_dst), mtu); 417 } else { 418 (void)snprintf(buf, sizeof(buf), 419 "%s unreachable - need to frag", 420 ipaddr_string(ndo, &dp->icmp_ip.ip_dst)); 421 } 422 } 423 break; 424 425 default: 426 fmt = tok2str(unreach2str, "#%d %%s unreachable", 427 dp->icmp_code); 428 (void)snprintf(buf, sizeof(buf), fmt, 429 ipaddr_string(ndo, &dp->icmp_ip.ip_dst)); 430 break; 431 } 432 break; 433 434 case ICMP_REDIRECT: 435 ND_TCHECK(dp->icmp_ip.ip_dst); 436 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s", 437 dp->icmp_code); 438 (void)snprintf(buf, sizeof(buf), fmt, 439 ipaddr_string(ndo, &dp->icmp_ip.ip_dst), 440 ipaddr_string(ndo, &dp->icmp_gwaddr)); 441 break; 442 443 case ICMP_ROUTERADVERT: 444 { 445 register const struct ih_rdiscovery *ihp; 446 register const struct id_rdiscovery *idp; 447 u_int lifetime, num, size; 448 449 (void)snprintf(buf, sizeof(buf), "router advertisement"); 450 cp = buf + strlen(buf); 451 452 ihp = (const struct ih_rdiscovery *)&dp->icmp_void; 453 ND_TCHECK(*ihp); 454 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); 455 cp = buf + strlen(buf); 456 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime); 457 if (lifetime < 60) { 458 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u", 459 lifetime); 460 } else if (lifetime < 60 * 60) { 461 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u", 462 lifetime / 60, lifetime % 60); 463 } else { 464 (void)snprintf(cp, sizeof(buf) - (cp - buf), 465 "%u:%02u:%02u", 466 lifetime / 3600, 467 (lifetime % 3600) / 60, 468 lifetime % 60); 469 } 470 cp = buf + strlen(buf); 471 472 num = ihp->ird_addrnum; 473 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num); 474 cp = buf + strlen(buf); 475 476 size = ihp->ird_addrsiz; 477 if (size != 2) { 478 (void)snprintf(cp, sizeof(buf) - (cp - buf), 479 " [size %d]", size); 480 break; 481 } 482 idp = (const struct id_rdiscovery *)&dp->icmp_data; 483 while (num-- > 0) { 484 ND_TCHECK(*idp); 485 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", 486 ipaddr_string(ndo, &idp->ird_addr), 487 EXTRACT_32BITS(&idp->ird_pref)); 488 cp = buf + strlen(buf); 489 ++idp; 490 } 491 } 492 break; 493 494 case ICMP_TIMXCEED: 495 ND_TCHECK(dp->icmp_ip.ip_dst); 496 switch (dp->icmp_code) { 497 498 case ICMP_TIMXCEED_INTRANS: 499 str = "time exceeded in-transit"; 500 break; 501 502 case ICMP_TIMXCEED_REASS: 503 str = "ip reassembly time exceeded"; 504 break; 505 506 default: 507 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d", 508 dp->icmp_code); 509 break; 510 } 511 break; 512 513 case ICMP_PARAMPROB: 514 if (dp->icmp_code) 515 (void)snprintf(buf, sizeof(buf), 516 "parameter problem - code %d", dp->icmp_code); 517 else { 518 ND_TCHECK(dp->icmp_pptr); 519 (void)snprintf(buf, sizeof(buf), 520 "parameter problem - octet %d", dp->icmp_pptr); 521 } 522 break; 523 524 case ICMP_MASKREPLY: 525 ND_TCHECK(dp->icmp_mask); 526 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", 527 EXTRACT_32BITS(&dp->icmp_mask)); 528 break; 529 530 case ICMP_TSTAMP: 531 ND_TCHECK(dp->icmp_seq); 532 (void)snprintf(buf, sizeof(buf), 533 "time stamp query id %u seq %u", 534 EXTRACT_16BITS(&dp->icmp_id), 535 EXTRACT_16BITS(&dp->icmp_seq)); 536 break; 537 538 case ICMP_TSTAMPREPLY: 539 ND_TCHECK(dp->icmp_ttime); 540 (void)snprintf(buf, sizeof(buf), 541 "time stamp reply id %u seq %u: org %s", 542 EXTRACT_16BITS(&dp->icmp_id), 543 EXTRACT_16BITS(&dp->icmp_seq), 544 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime))); 545 546 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", 547 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime))); 548 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", 549 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime))); 550 break; 551 552 default: 553 str = tok2str(icmp2str, "type-#%d", dp->icmp_type); 554 break; 555 } 556 ND_PRINT((ndo, "ICMP %s, length %u", str, plen)); 557 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ 558 uint16_t sum, icmp_sum; 559 560 if (ND_TTEST2(*bp, plen)) { 561 vec[0].ptr = (const uint8_t *)(const void *)dp; 562 vec[0].len = plen; 563 sum = in_cksum(vec, 1); 564 if (sum != 0) { 565 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum); 566 ND_PRINT((ndo, " (wrong icmp cksum %x (->%x)!)", 567 icmp_sum, 568 in_cksum_shouldbe(icmp_sum, sum))); 569 } 570 } 571 } 572 573 /* 574 * print the remnants of the IP packet. 575 * save the snaplength as this may get overidden in the IP printer. 576 */ 577 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(dp->icmp_type)) { 578 bp += 8; 579 ND_PRINT((ndo, "\n\t")); 580 ip = (const struct ip *)bp; 581 ndo->ndo_snaplen = ndo->ndo_snapend - bp; 582 snapend_save = ndo->ndo_snapend; 583 ip_print(ndo, bp, EXTRACT_16BITS(&ip->ip_len)); 584 ndo->ndo_snapend = snapend_save; 585 } 586 587 /* 588 * Attempt to decode the MPLS extensions only for some ICMP types. 589 */ 590 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) { 591 592 ND_TCHECK(*ext_dp); 593 594 /* 595 * Check first if the mpls extension header shows a non-zero length. 596 * If the length field is not set then silently verify the checksum 597 * to check if an extension header is present. This is expedient, 598 * however not all implementations set the length field proper. 599 */ 600 if (!ext_dp->icmp_length) { 601 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res; 602 vec[0].len = plen - ICMP_EXTD_MINLEN; 603 if (in_cksum(vec, 1)) { 604 return; 605 } 606 } 607 608 ND_PRINT((ndo, "\n\tMPLS extension v%u", 609 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)))); 610 611 /* 612 * Sanity checking of the header. 613 */ 614 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != 615 ICMP_MPLS_EXT_VERSION) { 616 ND_PRINT((ndo, " packet not supported")); 617 return; 618 } 619 620 hlen = plen - ICMP_EXTD_MINLEN; 621 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res; 622 vec[0].len = hlen; 623 ND_PRINT((ndo, ", checksum 0x%04x (%scorrect), length %u", 624 EXTRACT_16BITS(ext_dp->icmp_ext_checksum), 625 in_cksum(vec, 1) ? "in" : "", 626 hlen)); 627 628 hlen -= 4; /* subtract common header size */ 629 obj_tptr = (const uint8_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 = (const struct icmp_mpls_ext_object_header_t *)obj_tptr; 634 ND_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 ND_PRINT((ndo, "\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 ND_TCHECK2(*obj_tptr, 4); 660 raw_label = EXTRACT_32BITS(obj_tptr); 661 ND_PRINT((ndo, "\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label))); 662 if (MPLS_STACK(raw_label)) 663 ND_PRINT((ndo, ", [S]")); 664 ND_PRINT((ndo, ", ttl %u", MPLS_TTL(raw_label))); 665 break; 666 default: 667 print_unknown_data(ndo, 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(ndo, 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 ND_PRINT((ndo, "[|icmp]")); 690 } 691 /* 692 * Local Variables: 693 * c-style: whitesmith 694 * c-basic-offset: 8 695 * End: 696 */ 697
Indexes created Mon Jun 29 00:24:49 UTC 2026