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 /* \summary: Internet Control Message Protocol (ICMP) printer */ 23 24 #include <config.h> 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 nd_uint8_t icmp_type; /* type of message, see below */ 50 nd_uint8_t icmp_code; /* type sub code */ 51 nd_uint16_t icmp_cksum; /* ones complement cksum of struct */ 52 union { 53 nd_uint8_t ih_pptr; /* ICMP_PARAMPROB */ 54 nd_ipv4 ih_gwaddr; /* ICMP_REDIRECT */ 55 struct ih_idseq { 56 nd_uint16_t icd_id; 57 nd_uint16_t icd_seq; 58 } ih_idseq; 59 nd_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 nd_uint32_t its_otime; 69 nd_uint32_t its_rtime; 70 nd_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 nd_uint32_t id_mask; 77 nd_byte 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 /* 88 * Lower bounds on packet lengths for various types. 89 * For the error advice packets must first insure that the 90 * packet is large enough to contain the returned ip header. 91 * Only then can we do the check to see if 64 bits of packet 92 * data have been returned, since we need to check the returned 93 * ip header length. 94 */ 95 #define ICMP_MINLEN 8 /* abs minimum */ 96 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */ 97 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */ 98 #define ICMP_MASKLEN 12 /* address mask */ 99 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */ 100 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8) 101 /* N.B.: must separately check that ip_hl >= 5 */ 102 103 /* 104 * Definition of type and code field values. 105 */ 106 #define ICMP_ECHOREPLY 0 /* echo reply */ 107 #define ICMP_UNREACH 3 /* dest unreachable, codes: */ 108 #define ICMP_UNREACH_NET 0 /* bad net */ 109 #define ICMP_UNREACH_HOST 1 /* bad host */ 110 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */ 111 #define ICMP_UNREACH_PORT 3 /* bad port */ 112 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */ 113 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */ 114 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */ 115 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */ 116 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */ 117 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */ 118 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */ 119 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */ 120 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */ 121 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */ 122 #define ICMP_REDIRECT 5 /* shorter route, codes: */ 123 #define ICMP_REDIRECT_NET 0 /* for network */ 124 #define ICMP_REDIRECT_HOST 1 /* for host */ 125 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */ 126 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */ 127 #define ICMP_ECHO 8 /* echo service */ 128 #define ICMP_ROUTERADVERT 9 /* router advertisement */ 129 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */ 130 #define ICMP_TIMXCEED 11 /* time exceeded, code: */ 131 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */ 132 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */ 133 #define ICMP_PARAMPROB 12 /* ip header bad */ 134 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */ 135 #define ICMP_TSTAMP 13 /* timestamp request */ 136 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */ 137 #define ICMP_IREQ 15 /* information request */ 138 #define ICMP_IREQREPLY 16 /* information reply */ 139 #define ICMP_MASKREQ 17 /* address mask request */ 140 #define ICMP_MASKREPLY 18 /* address mask reply */ 141 142 #define ICMP_MAXTYPE 18 143 144 #define ICMP_ERRTYPE(type) \ 145 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \ 146 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \ 147 (type) == ICMP_PARAMPROB) 148 #define ICMP_MULTIPART_EXT_TYPE(type) \ 149 ((type) == ICMP_UNREACH || \ 150 (type) == ICMP_TIMXCEED || \ 151 (type) == ICMP_PARAMPROB) 152 /* rfc1700 */ 153 #ifndef ICMP_UNREACH_NET_UNKNOWN 154 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */ 155 #endif 156 #ifndef ICMP_UNREACH_HOST_UNKNOWN 157 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */ 158 #endif 159 #ifndef ICMP_UNREACH_ISOLATED 160 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */ 161 #endif 162 #ifndef ICMP_UNREACH_NET_PROHIB 163 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */ 164 #endif 165 #ifndef ICMP_UNREACH_HOST_PROHIB 166 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */ 167 #endif 168 #ifndef ICMP_UNREACH_TOSNET 169 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */ 170 #endif 171 #ifndef ICMP_UNREACH_TOSHOST 172 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */ 173 #endif 174 175 /* rfc1716 */ 176 #ifndef ICMP_UNREACH_FILTER_PROHIB 177 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */ 178 #endif 179 #ifndef ICMP_UNREACH_HOST_PRECEDENCE 180 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */ 181 #endif 182 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF 183 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */ 184 #endif 185 186 /* Most of the icmp types */ 187 static const struct tok icmp2str[] = { 188 { ICMP_ECHOREPLY, "echo reply" }, 189 { ICMP_SOURCEQUENCH, "source quench" }, 190 { ICMP_ECHO, "echo request" }, 191 { ICMP_ROUTERSOLICIT, "router solicitation" }, 192 { ICMP_TSTAMP, "time stamp request" }, 193 { ICMP_TSTAMPREPLY, "time stamp reply" }, 194 { ICMP_IREQ, "information request" }, 195 { ICMP_IREQREPLY, "information reply" }, 196 { ICMP_MASKREQ, "address mask request" }, 197 { 0, NULL } 198 }; 199 200 /* rfc1191 */ 201 struct mtu_discovery { 202 nd_uint16_t unused; 203 nd_uint16_t nexthopmtu; 204 }; 205 206 /* rfc1256 */ 207 struct ih_rdiscovery { 208 nd_uint8_t ird_addrnum; 209 nd_uint8_t ird_addrsiz; 210 nd_uint16_t ird_lifetime; 211 }; 212 213 struct id_rdiscovery { 214 nd_uint32_t ird_addr; 215 nd_uint32_t ird_pref; 216 }; 217 218 /* 219 * RFC 4884 - Extended ICMP to Support Multi-Part Messages 220 * 221 * This is a general extension mechanism, based on the mechanism 222 * in draft-bonica-icmp-mpls-02 ICMP Extensions for MultiProtocol 223 * Label Switching. 224 * 225 * The Destination Unreachable, Time Exceeded 226 * and Parameter Problem messages are slightly changed as per 227 * the above RFC. A new Length field gets added to give 228 * the caller an idea about the length of the piggybacked 229 * IP packet before the extension header starts. 230 * 231 * The Length field represents length of the padded "original datagram" 232 * field measured in 32-bit words. 233 * 234 * 0 1 2 3 235 * 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 1 236 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 237 * | Type | Code | Checksum | 238 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 239 * | unused | Length | unused | 240 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 241 * | Internet Header + leading octets of original datagram | 242 * | | 243 * | // | 244 * | | 245 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 */ 247 248 struct icmp_ext_t { 249 nd_uint8_t icmp_type; 250 nd_uint8_t icmp_code; 251 nd_uint16_t icmp_checksum; 252 nd_byte icmp_reserved; 253 nd_uint8_t icmp_length; 254 nd_byte icmp_reserved2[2]; 255 nd_byte icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */ 256 nd_byte icmp_ext_version_res[2]; 257 nd_uint16_t icmp_ext_checksum; 258 nd_byte icmp_ext_data[1]; 259 }; 260 261 /* 262 * Extract version from the first octet of icmp_ext_version_res. 263 */ 264 #define ICMP_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) 265 266 /* 267 * Current version. 268 */ 269 #define ICMP_EXT_VERSION 2 270 271 /* 272 * Extension object class numbers. 273 * 274 * Class 1 dates back to draft-bonica-icmp-mpls-02. 275 */ 276 277 /* rfc4950 */ 278 #define MPLS_STACK_ENTRY_OBJECT_CLASS 1 279 280 struct icmp_multipart_ext_object_header_t { 281 nd_uint16_t length; 282 nd_uint8_t class_num; 283 nd_uint8_t ctype; 284 }; 285 286 static const struct tok icmp_multipart_ext_obj_values[] = { 287 { 1, "MPLS Stack Entry" }, 288 { 2, "Interface Identification" }, 289 { 0, NULL} 290 }; 291 292 /* prototypes */ 293 const char *icmp_tstamp_print(u_int); 294 295 /* print the milliseconds since midnight UTC */ 296 const char * 297 icmp_tstamp_print(u_int tstamp) 298 { 299 u_int msec,sec,min,hrs; 300 301 static char buf[64]; 302 303 msec = tstamp % 1000; 304 sec = tstamp / 1000; 305 min = sec / 60; sec -= min * 60; 306 hrs = min / 60; min -= hrs * 60; 307 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec); 308 return buf; 309 } 310 311 void 312 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2, 313 int fragmented) 314 { 315 char *cp; 316 const struct icmp *dp; 317 uint8_t icmp_type, icmp_code; 318 const struct icmp_ext_t *ext_dp; 319 const struct ip *ip; 320 const char *str; 321 const struct ip *oip; 322 uint8_t ip_proto; 323 const struct udphdr *ouh; 324 const uint8_t *obj_tptr; 325 uint32_t raw_label; 326 const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header; 327 u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype; 328 uint16_t dport; 329 char buf[MAXHOSTNAMELEN + 100]; 330 struct cksum_vec vec[1]; 331 332 ndo->ndo_protocol = "icmp"; 333 dp = (const struct icmp *)bp; 334 ext_dp = (const struct icmp_ext_t *)bp; 335 ip = (const struct ip *)bp2; 336 str = buf; 337 338 icmp_type = GET_U_1(dp->icmp_type); 339 icmp_code = GET_U_1(dp->icmp_code); 340 switch (icmp_type) { 341 342 case ICMP_ECHO: 343 case ICMP_ECHOREPLY: 344 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u", 345 icmp_type == ICMP_ECHO ? 346 "request" : "reply", 347 GET_BE_U_2(dp->icmp_id), 348 GET_BE_U_2(dp->icmp_seq)); 349 break; 350 351 case ICMP_UNREACH: 352 switch (icmp_code) { 353 354 case ICMP_UNREACH_NET: 355 (void)snprintf(buf, sizeof(buf), 356 "net %s unreachable", 357 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 358 break; 359 360 case ICMP_UNREACH_HOST: 361 (void)snprintf(buf, sizeof(buf), 362 "host %s unreachable", 363 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 364 break; 365 366 case ICMP_UNREACH_PROTOCOL: 367 (void)snprintf(buf, sizeof(buf), 368 "%s protocol %u unreachable", 369 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), 370 GET_U_1(dp->icmp_ip.ip_p)); 371 break; 372 373 case ICMP_UNREACH_PORT: 374 ND_TCHECK_1(dp->icmp_ip.ip_p); 375 oip = &dp->icmp_ip; 376 hlen = IP_HL(oip) * 4; 377 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen); 378 dport = GET_BE_U_2(ouh->uh_dport); 379 ip_proto = GET_U_1(oip->ip_p); 380 switch (ip_proto) { 381 382 case IPPROTO_TCP: 383 (void)snprintf(buf, sizeof(buf), 384 "%s tcp port %s unreachable", 385 GET_IPADDR_STRING(oip->ip_dst), 386 tcpport_string(ndo, dport)); 387 break; 388 389 case IPPROTO_UDP: 390 (void)snprintf(buf, sizeof(buf), 391 "%s udp port %s unreachable", 392 GET_IPADDR_STRING(oip->ip_dst), 393 udpport_string(ndo, dport)); 394 break; 395 396 default: 397 (void)snprintf(buf, sizeof(buf), 398 "%s protocol %u port %u unreachable", 399 GET_IPADDR_STRING(oip->ip_dst), 400 ip_proto, dport); 401 break; 402 } 403 break; 404 405 case ICMP_UNREACH_NEEDFRAG: 406 { 407 const struct mtu_discovery *mp; 408 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void; 409 mtu = GET_BE_U_2(mp->nexthopmtu); 410 if (mtu) { 411 (void)snprintf(buf, sizeof(buf), 412 "%s unreachable - need to frag (mtu %u)", 413 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu); 414 } else { 415 (void)snprintf(buf, sizeof(buf), 416 "%s unreachable - need to frag", 417 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 418 } 419 } 420 break; 421 422 case ICMP_UNREACH_SRCFAIL: 423 (void)snprintf(buf, sizeof(buf), 424 "%s unreachable - source route failed", 425 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 426 break; 427 428 case ICMP_UNREACH_NET_UNKNOWN: 429 (void)snprintf(buf, sizeof(buf), 430 "net %s unreachable - unknown", 431 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 432 break; 433 434 case ICMP_UNREACH_HOST_UNKNOWN: 435 (void)snprintf(buf, sizeof(buf), 436 "host %s unreachable - unknown", 437 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 438 break; 439 440 case ICMP_UNREACH_ISOLATED: 441 (void)snprintf(buf, sizeof(buf), 442 "%s unreachable - source host isolated", 443 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 444 break; 445 446 case ICMP_UNREACH_NET_PROHIB: 447 (void)snprintf(buf, sizeof(buf), 448 "net %s unreachable - admin prohibited", 449 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 450 break; 451 452 case ICMP_UNREACH_HOST_PROHIB: 453 (void)snprintf(buf, sizeof(buf), 454 "host %s unreachable - admin prohibited", 455 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 456 break; 457 458 case ICMP_UNREACH_TOSNET: 459 (void)snprintf(buf, sizeof(buf), 460 "net %s unreachable - tos prohibited", 461 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 462 break; 463 464 case ICMP_UNREACH_TOSHOST: 465 (void)snprintf(buf, sizeof(buf), 466 "host %s unreachable - tos prohibited", 467 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 468 break; 469 470 case ICMP_UNREACH_FILTER_PROHIB: 471 (void)snprintf(buf, sizeof(buf), 472 "host %s unreachable - admin prohibited filter", 473 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 474 break; 475 476 case ICMP_UNREACH_HOST_PRECEDENCE: 477 (void)snprintf(buf, sizeof(buf), 478 "host %s unreachable - host precedence violation", 479 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 480 break; 481 482 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 483 (void)snprintf(buf, sizeof(buf), 484 "host %s unreachable - precedence cutoff", 485 GET_IPADDR_STRING(dp->icmp_ip.ip_dst)); 486 break; 487 488 default: 489 (void)snprintf(buf, sizeof(buf), 490 "%s unreachable - #%u", 491 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), 492 icmp_code); 493 break; 494 } 495 break; 496 497 case ICMP_REDIRECT: 498 switch (icmp_code) { 499 500 case ICMP_REDIRECT_NET: 501 (void)snprintf(buf, sizeof(buf), 502 "redirect %s to net %s", 503 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), 504 GET_IPADDR_STRING(dp->icmp_gwaddr)); 505 break; 506 507 case ICMP_REDIRECT_HOST: 508 (void)snprintf(buf, sizeof(buf), 509 "redirect %s to host %s", 510 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), 511 GET_IPADDR_STRING(dp->icmp_gwaddr)); 512 break; 513 514 case ICMP_REDIRECT_TOSNET: 515 (void)snprintf(buf, sizeof(buf), 516 "redirect-tos %s to net %s", 517 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), 518 GET_IPADDR_STRING(dp->icmp_gwaddr)); 519 break; 520 521 case ICMP_REDIRECT_TOSHOST: 522 (void)snprintf(buf, sizeof(buf), 523 "redirect-tos %s to host %s", 524 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), 525 GET_IPADDR_STRING(dp->icmp_gwaddr)); 526 break; 527 528 default: 529 (void)snprintf(buf, sizeof(buf), 530 "redirect-#%u %s to %s", icmp_code, 531 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), 532 GET_IPADDR_STRING(dp->icmp_gwaddr)); 533 break; 534 } 535 break; 536 537 case ICMP_ROUTERADVERT: 538 { 539 const struct ih_rdiscovery *ihp; 540 const struct id_rdiscovery *idp; 541 u_int lifetime, num, size; 542 543 (void)snprintf(buf, sizeof(buf), "router advertisement"); 544 cp = buf + strlen(buf); 545 546 ihp = (const struct ih_rdiscovery *)&dp->icmp_void; 547 ND_TCHECK_SIZE(ihp); 548 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); 549 cp = buf + strlen(buf); 550 lifetime = GET_BE_U_2(ihp->ird_lifetime); 551 if (lifetime < 60) { 552 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u", 553 lifetime); 554 } else if (lifetime < 60 * 60) { 555 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u", 556 lifetime / 60, lifetime % 60); 557 } else { 558 (void)snprintf(cp, sizeof(buf) - (cp - buf), 559 "%u:%02u:%02u", 560 lifetime / 3600, 561 (lifetime % 3600) / 60, 562 lifetime % 60); 563 } 564 cp = buf + strlen(buf); 565 566 num = GET_U_1(ihp->ird_addrnum); 567 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num); 568 cp = buf + strlen(buf); 569 570 size = GET_U_1(ihp->ird_addrsiz); 571 if (size != 2) { 572 (void)snprintf(cp, sizeof(buf) - (cp - buf), 573 " [size %u]", size); 574 break; 575 } 576 idp = (const struct id_rdiscovery *)&dp->icmp_data; 577 while (num > 0) { 578 ND_TCHECK_SIZE(idp); 579 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", 580 GET_IPADDR_STRING(idp->ird_addr), 581 GET_BE_U_4(idp->ird_pref)); 582 cp = buf + strlen(buf); 583 ++idp; 584 num--; 585 } 586 } 587 break; 588 589 case ICMP_TIMXCEED: 590 ND_TCHECK_4(dp->icmp_ip.ip_dst); 591 switch (icmp_code) { 592 593 case ICMP_TIMXCEED_INTRANS: 594 str = "time exceeded in-transit"; 595 break; 596 597 case ICMP_TIMXCEED_REASS: 598 str = "ip reassembly time exceeded"; 599 break; 600 601 default: 602 (void)snprintf(buf, sizeof(buf), "time exceeded-#%u", 603 icmp_code); 604 break; 605 } 606 break; 607 608 case ICMP_PARAMPROB: 609 if (icmp_code) 610 (void)snprintf(buf, sizeof(buf), 611 "parameter problem - code %u", icmp_code); 612 else { 613 (void)snprintf(buf, sizeof(buf), 614 "parameter problem - octet %u", 615 GET_U_1(dp->icmp_pptr)); 616 } 617 break; 618 619 case ICMP_MASKREPLY: 620 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x", 621 GET_BE_U_4(dp->icmp_mask)); 622 break; 623 624 case ICMP_TSTAMP: 625 (void)snprintf(buf, sizeof(buf), 626 "time stamp query id %u seq %u", 627 GET_BE_U_2(dp->icmp_id), 628 GET_BE_U_2(dp->icmp_seq)); 629 break; 630 631 case ICMP_TSTAMPREPLY: 632 ND_TCHECK_4(dp->icmp_ttime); 633 (void)snprintf(buf, sizeof(buf), 634 "time stamp reply id %u seq %u: org %s", 635 GET_BE_U_2(dp->icmp_id), 636 GET_BE_U_2(dp->icmp_seq), 637 icmp_tstamp_print(GET_BE_U_4(dp->icmp_otime))); 638 639 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s", 640 icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime))); 641 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s", 642 icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime))); 643 break; 644 645 default: 646 str = tok2str(icmp2str, "type-#%u", icmp_type); 647 break; 648 } 649 ND_PRINT("ICMP %s, length %u", str, plen); 650 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */ 651 if (ND_TTEST_LEN(bp, plen)) { 652 uint16_t sum; 653 654 vec[0].ptr = (const uint8_t *)(const void *)dp; 655 vec[0].len = plen; 656 sum = in_cksum(vec, 1); 657 if (sum != 0) { 658 uint16_t icmp_sum = GET_BE_U_2(dp->icmp_cksum); 659 ND_PRINT(" (wrong icmp cksum %x (->%x)!)", 660 icmp_sum, 661 in_cksum_shouldbe(icmp_sum, sum)); 662 } 663 } 664 } 665 666 /* 667 * print the remnants of the IP packet. 668 * save the snaplength as this may get overridden in the IP printer. 669 */ 670 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) { 671 const u_char *snapend_save; 672 673 bp += 8; 674 ND_PRINT("\n\t"); 675 ip = (const struct ip *)bp; 676 snapend_save = ndo->ndo_snapend; 677 /* 678 * Update the snapend because extensions (MPLS, ...) may be 679 * present after the IP packet. In this case the current 680 * (outer) packet's snapend is not what ip_print() needs to 681 * decode an IP packet nested in the middle of an ICMP payload. 682 * 683 * This prevents that, in ip_print(), for the nested IP packet, 684 * the remaining length < remaining caplen. 685 */ 686 ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len), 687 ndo->ndo_snapend); 688 ip_print(ndo, bp, GET_BE_U_2(ip->ip_len)); 689 ndo->ndo_snapend = snapend_save; 690 } 691 692 /* ndo_protocol reassignment after ip_print() call */ 693 ndo->ndo_protocol = "icmp"; 694 695 /* 696 * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types. 697 */ 698 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) { 699 700 ND_TCHECK_SIZE(ext_dp); 701 702 /* 703 * Check first if the multi-part extension header shows a non-zero length. 704 * If the length field is not set then silently verify the checksum 705 * to check if an extension header is present. This is expedient, 706 * however not all implementations set the length field proper. 707 */ 708 if (GET_U_1(ext_dp->icmp_length) == 0 && 709 ND_TTEST_LEN(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) { 710 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res; 711 vec[0].len = plen - ICMP_EXTD_MINLEN; 712 if (in_cksum(vec, 1)) { 713 return; 714 } 715 } 716 717 ND_PRINT("\n\tICMP Multi-Part extension v%u", 718 ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); 719 720 /* 721 * Sanity checking of the header. 722 */ 723 if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != 724 ICMP_EXT_VERSION) { 725 ND_PRINT(" packet not supported"); 726 return; 727 } 728 729 hlen = plen - ICMP_EXTD_MINLEN; 730 if (ND_TTEST_LEN(ext_dp->icmp_ext_version_res, hlen)) { 731 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res; 732 vec[0].len = hlen; 733 ND_PRINT(", checksum 0x%04x (%scorrect), length %u", 734 GET_BE_U_2(ext_dp->icmp_ext_checksum), 735 in_cksum(vec, 1) ? "in" : "", 736 hlen); 737 } 738 739 hlen -= 4; /* subtract common header size */ 740 obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data; 741 742 while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) { 743 744 icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr; 745 ND_TCHECK_SIZE(icmp_multipart_ext_object_header); 746 obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length); 747 obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num); 748 obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype); 749 obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t); 750 751 ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u", 752 tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num), 753 obj_class_num, 754 obj_ctype, 755 obj_tlen); 756 757 hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */ 758 759 /* infinite loop protection */ 760 if ((obj_class_num == 0) || 761 (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) { 762 return; 763 } 764 obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t); 765 766 switch (obj_class_num) { 767 case MPLS_STACK_ENTRY_OBJECT_CLASS: 768 switch(obj_ctype) { 769 case 1: 770 raw_label = GET_BE_U_4(obj_tptr); 771 ND_PRINT("\n\t label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label)); 772 if (MPLS_STACK(raw_label)) 773 ND_PRINT(", [S]"); 774 ND_PRINT(", ttl %u", MPLS_TTL(raw_label)); 775 break; 776 default: 777 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); 778 } 779 break; 780 781 default: 782 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); 783 break; 784 } 785 if (hlen < obj_tlen) 786 break; 787 hlen -= obj_tlen; 788 obj_tptr += obj_tlen; 789 } 790 } 791 792 return; 793 trunc: 794 nd_print_trunc(ndo); 795 } 796