The Tcpdump Group git mirrors - tcpdump/blob - print-ether.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
   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: Ethernet printer */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include "netdissect.h"
  31 #include "extract.h"
  32 #include "addrtoname.h"
  33 #include "ethertype.h"
  34
  35 /*
  36  * Structure of an Ethernet header.
  37  */
  38 struct  ether_header {
  39         nd_mac_addr     ether_dhost;
  40         nd_mac_addr     ether_shost;
  41         nd_uint16_t     ether_length_type;
  42 };
  43
  44 /*
  45  * Length of an Ethernet header; note that some compilers may pad
  46  * "struct ether_header" to a multiple of 4 bytes, for example, so
  47  * "sizeof (struct ether_header)" may not give the right answer.
  48  */
  49 #define ETHER_HDRLEN            14
  50
  51 const struct tok ethertype_values[] = {
  52     { ETHERTYPE_IP,             "IPv4" },
  53     { ETHERTYPE_MPLS,           "MPLS unicast" },
  54     { ETHERTYPE_MPLS_MULTI,     "MPLS multicast" },
  55     { ETHERTYPE_IPV6,           "IPv6" },
  56     { ETHERTYPE_8021Q,          "802.1Q" },
  57     { ETHERTYPE_8021Q9100,      "802.1Q-9100" },
  58     { ETHERTYPE_8021QinQ,       "802.1Q-QinQ" },
  59     { ETHERTYPE_8021Q9200,      "802.1Q-9200" },
  60     { ETHERTYPE_VMAN,           "VMAN" },
  61     { ETHERTYPE_PUP,            "PUP" },
  62     { ETHERTYPE_ARP,            "ARP"},
  63     { ETHERTYPE_REVARP,         "Reverse ARP"},
  64     { ETHERTYPE_NS,             "NS" },
  65     { ETHERTYPE_SPRITE,         "Sprite" },
  66     { ETHERTYPE_TRAIL,          "Trail" },
  67     { ETHERTYPE_MOPDL,          "MOP DL" },
  68     { ETHERTYPE_MOPRC,          "MOP RC" },
  69     { ETHERTYPE_DN,             "DN" },
  70     { ETHERTYPE_LAT,            "LAT" },
  71     { ETHERTYPE_SCA,            "SCA" },
  72     { ETHERTYPE_TEB,            "TEB" },
  73     { ETHERTYPE_LANBRIDGE,      "Lanbridge" },
  74     { ETHERTYPE_DECDNS,         "DEC DNS" },
  75     { ETHERTYPE_DECDTS,         "DEC DTS" },
  76     { ETHERTYPE_VEXP,           "VEXP" },
  77     { ETHERTYPE_VPROD,          "VPROD" },
  78     { ETHERTYPE_ATALK,          "Appletalk" },
  79     { ETHERTYPE_AARP,           "Appletalk ARP" },
  80     { ETHERTYPE_IPX,            "IPX" },
  81     { ETHERTYPE_PPP,            "PPP" },
  82     { ETHERTYPE_MPCP,           "MPCP" },
  83     { ETHERTYPE_SLOW,           "Slow Protocols" },
  84     { ETHERTYPE_PPPOED,         "PPPoE D" },
  85     { ETHERTYPE_PPPOES,         "PPPoE S" },
  86     { ETHERTYPE_EAPOL,          "EAPOL" },
  87     { ETHERTYPE_RRCP,           "RRCP" },
  88     { ETHERTYPE_MS_NLB_HB,      "MS NLB heartbeat" },
  89     { ETHERTYPE_JUMBO,          "Jumbo" },
  90     { ETHERTYPE_NSH,            "NSH" },
  91     { ETHERTYPE_LOOPBACK,       "Loopback" },
  92     { ETHERTYPE_ISO,            "OSI" },
  93     { ETHERTYPE_GRE_ISO,        "GRE-OSI" },
  94     { ETHERTYPE_CFM_OLD,        "CFM (old)" },
  95     { ETHERTYPE_CFM,            "CFM" },
  96     { ETHERTYPE_IEEE1905_1,     "IEEE1905.1" },
  97     { ETHERTYPE_LLDP,           "LLDP" },
  98     { ETHERTYPE_TIPC,           "TIPC"},
  99     { ETHERTYPE_GEONET_OLD,     "GeoNet (old)"},
 100     { ETHERTYPE_GEONET,         "GeoNet"},
 101     { ETHERTYPE_CALM_FAST,      "CALM FAST"},
 102     { ETHERTYPE_AOE,            "AoE" },
 103     { 0, NULL}
 104 };
 105
 106 static void
 107 ether_addresses_print(netdissect_options *ndo, const u_char *src,
 108                       const u_char *dst)
 109 {
 110         ND_PRINT("%s > %s, ",
 111                  etheraddr_string(ndo, src), etheraddr_string(ndo, dst));
 112 }
 113
 114 static void
 115 ether_type_print(netdissect_options *ndo, uint16_t type)
 116 {
 117         if (!ndo->ndo_qflag)
 118                 ND_PRINT("ethertype %s (0x%04x)",
 119                          tok2str(ethertype_values, "Unknown", type), type);
 120         else
 121                 ND_PRINT("%s",
 122                          tok2str(ethertype_values, "Unknown Ethertype (0x%04x)", type));
 123 }
 124
 125 /*
 126  * Common code for printing Ethernet frames.
 127  *
 128  * It can handle Ethernet headers with extra tag information inserted
 129  * after the destination and source addresses, as is inserted by some
 130  * switch chips, and extra encapsulation header information before
 131  * printing Ethernet header information (such as a LANE ID for ATM LANE).
 132  */
 133 static u_int
 134 ether_print_common(netdissect_options *ndo, const u_char *p, u_int length,
 135     u_int caplen,
 136     void (*print_switch_tag)(netdissect_options *ndo, const u_char *),
 137     u_int switch_tag_len,
 138     void (*print_encap_header)(netdissect_options *ndo, const u_char *),
 139     const u_char *encap_header_arg)
 140 {
 141         const struct ether_header *ehp;
 142         u_int orig_length;
 143         u_int hdrlen;
 144         u_short length_type;
 145         int printed_length;
 146         int llc_hdrlen;
 147         struct lladdr_info src, dst;
 148
 149         if (caplen < ETHER_HDRLEN + switch_tag_len) {
 150                 nd_print_trunc(ndo);
 151                 return (caplen);
 152         }
 153         if (length < ETHER_HDRLEN + switch_tag_len) {
 154                 nd_print_trunc(ndo);
 155                 return (length);
 156         }
 157
 158         if (print_encap_header != NULL)
 159                 (*print_encap_header)(ndo, encap_header_arg);
 160
 161         orig_length = length;
 162
 163         /*
 164          * Get the source and destination addresses, skip past them,
 165          * and print them if we're printing the link-layer header.
 166          */
 167         ehp = (const struct ether_header *)p;
 168         src.addr = ehp->ether_shost;
 169         src.addr_string = etheraddr_string;
 170         dst.addr = ehp->ether_dhost;
 171         dst.addr_string = etheraddr_string;
 172
 173         length -= 2*MAC_ADDR_LEN;
 174         caplen -= 2*MAC_ADDR_LEN;
 175         p += 2*MAC_ADDR_LEN;
 176         hdrlen = 2*MAC_ADDR_LEN;
 177
 178         if (ndo->ndo_eflag)
 179                 ether_addresses_print(ndo, src.addr, dst.addr);
 180
 181         /*
 182          * Print the switch tag, if we have one, and skip past it.
 183          */
 184         if (print_switch_tag != NULL)
 185                 (*print_switch_tag)(ndo, p);
 186
 187         length -= switch_tag_len;
 188         caplen -= switch_tag_len;
 189         p += switch_tag_len;
 190         hdrlen += switch_tag_len;
 191
 192         /*
 193          * Get the length/type field, skip past it, and print it
 194          * if we're printing the link-layer header.
 195          */
 196         length_type = GET_BE_U_2(p);
 197
 198         length -= 2;
 199         caplen += 2;
 200         p += 2;
 201         hdrlen += 2;
 202
 203         /*
 204          * Process VLAN tag types.
 205          */
 206         printed_length = 0;
 207         while (length_type == ETHERTYPE_8021Q  ||
 208                 length_type == ETHERTYPE_8021Q9100 ||
 209                 length_type == ETHERTYPE_8021Q9200 ||
 210                 length_type == ETHERTYPE_8021QinQ) {
 211                 /*
 212                  * It has a VLAN tag.
 213                  * Print VLAN information, and then go back and process
 214                  * the enclosed type field.
 215                  */
 216                 if (caplen < 4) {
 217                         ndo->ndo_protocol = "vlan";
 218                         nd_print_trunc(ndo);
 219                         return (hdrlen + caplen);
 220                 }
 221                 if (length < 4) {
 222                         ndo->ndo_protocol = "vlan";
 223                         nd_print_trunc(ndo);
 224                         return (hdrlen + length);
 225                 }
 226                 if (ndo->ndo_eflag) {
 227                         uint16_t tag = GET_BE_U_2(p);
 228
 229                         ether_type_print(ndo, length_type);
 230                         if (!printed_length) {
 231                                 ND_PRINT(", length %u: ", orig_length);
 232                                 printed_length = 1;
 233                         } else
 234                                 ND_PRINT(", ");
 235                         ND_PRINT("%s, ", ieee8021q_tci_string(tag));
 236                 }
 237
 238                 length_type = GET_BE_U_2(p + 2);
 239                 p += 4;
 240                 length -= 4;
 241                 caplen -= 4;
 242                 hdrlen += 4;
 243         }
 244
 245         /*
 246          * We now have the final length/type field.
 247          */
 248         if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
 249                 /*
 250                  * It's a length field, containing the length of the
 251                  * remaining payload; use it as such, as long as
 252                  * it's not too large (bigger than the actual payload).
 253                  */
 254                 if (length_type < length) {
 255                         length = length_type;
 256                         if (caplen > length)
 257                                 caplen = length;
 258                 }
 259
 260                 /*
 261                  * Cut off the snapshot length to the end of the
 262                  * payload.
 263                  */
 264                 nd_push_snapend(ndo, p + length);
 265
 266                 if (ndo->ndo_eflag) {
 267                         ND_PRINT("802.3");
 268                         if (!printed_length)
 269                                 ND_PRINT(", length %u: ", length);
 270                 }
 271
 272                 /*
 273                  * An LLC header follows the length.  Print that and
 274                  * higher layers.
 275                  */
 276                 llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
 277                 if (llc_hdrlen < 0) {
 278                         /* packet type not known, print raw packet */
 279                         if (!ndo->ndo_suppress_default_print)
 280                                 ND_DEFAULTPRINT(p, caplen);
 281                         llc_hdrlen = -llc_hdrlen;
 282                 }
 283                 hdrlen += llc_hdrlen;
 284                 nd_pop_packet_info(ndo);
 285         } else if (length_type == ETHERTYPE_JUMBO) {
 286                 /*
 287                  * It's a type field, with the type for Alteon jumbo frames.
 288                  * See
 289                  *
 290                  *      http://tools.ietf.org/html/draft-ietf-isis-ext-eth-01
 291                  *
 292                  * which indicates that, following the type field,
 293                  * there's an LLC header and payload.
 294                  */
 295                 /* Try to print the LLC-layer header & higher layers */
 296                 llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
 297                 if (llc_hdrlen < 0) {
 298                         /* packet type not known, print raw packet */
 299                         if (!ndo->ndo_suppress_default_print)
 300                                 ND_DEFAULTPRINT(p, caplen);
 301                         llc_hdrlen = -llc_hdrlen;
 302                 }
 303                 hdrlen += llc_hdrlen;
 304         } else {
 305                 /*
 306                  * It's a type field with some other value.
 307                  */
 308                 if (ndo->ndo_eflag) {
 309                         ether_type_print(ndo, length_type);
 310                         if (!printed_length)
 311                                 ND_PRINT(", length %u: ", orig_length);
 312                         else
 313                                 ND_PRINT(", ");
 314                 }
 315                 if (ethertype_print(ndo, length_type, p, length, caplen, &src, &dst) == 0) {
 316                         /* type not known, print raw packet */
 317                         if (!ndo->ndo_eflag) {
 318                                 /*
 319                                  * We didn't print the full link-layer
 320                                  * header, as -e wasn't specified, so
 321                                  * print only the source and destination
 322                                  * MAC addresses and the final Ethernet
 323                                  * type.
 324                                  */
 325                                 ether_addresses_print(ndo, src.addr, dst.addr);
 326                                 ether_type_print(ndo, length_type);
 327                                 ND_PRINT(", length %u: ", orig_length);
 328                         }
 329
 330                         if (!ndo->ndo_suppress_default_print)
 331                                 ND_DEFAULTPRINT(p, caplen);
 332                 }
 333         }
 334         return (hdrlen);
 335 }
 336
 337 /*
 338  * Print an Ethernet frame while specyfing a non-standard Ethernet header
 339  * length.
 340  * This might be encapsulated within another frame; we might be passed
 341  * a pointer to a function that can print header information for that
 342  * frame's protocol, and an argument to pass to that function.
 343  *
 344  * FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
 345  */
 346 u_int
 347 ether_print_switch_tag(netdissect_options *ndo, const u_char *p, u_int length,
 348     u_int caplen,
 349     void (*print_switch_tag)(netdissect_options *, const u_char *),
 350     u_int switch_tag_len)
 351 {
 352         return (ether_print_common(ndo, p, length, caplen, print_switch_tag,
 353                                    switch_tag_len, NULL, NULL));
 354 }
 355
 356 /*
 357  * Print an Ethernet frame.
 358  * This might be encapsulated within another frame; we might be passed
 359  * a pointer to a function that can print header information for that
 360  * frame's protocol, and an argument to pass to that function.
 361  *
 362  * FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
 363  */
 364 u_int
 365 ether_print(netdissect_options *ndo,
 366             const u_char *p, u_int length, u_int caplen,
 367             void (*print_encap_header)(netdissect_options *ndo, const u_char *),
 368             const u_char *encap_header_arg)
 369 {
 370         ndo->ndo_protocol = "ether";
 371         return (ether_print_common(ndo, p, length, caplen, NULL, 0,
 372                                     print_encap_header, encap_header_arg));
 373 }
 374
 375 /*
 376  * This is the top level routine of the printer.  'p' points
 377  * to the ether header of the packet, 'h->len' is the length
 378  * of the packet off the wire, and 'h->caplen' is the number
 379  * of bytes actually captured.
 380  */
 381 u_int
 382 ether_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
 383                const u_char *p)
 384 {
 385         ndo->ndo_protocol = "ether_if";
 386         return (ether_print(ndo, p, h->len, h->caplen, NULL, NULL));
 387 }
 388
 389 /*
 390  * This is the top level routine of the printer.  'p' points
 391  * to the ether header of the packet, 'h->len' is the length
 392  * of the packet off the wire, and 'h->caplen' is the number
 393  * of bytes actually captured.
 394  *
 395  * This is for DLT_NETANALYZER, which has a 4-byte pseudo-header
 396  * before the Ethernet header.
 397  */
 398 u_int
 399 netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
 400                      const u_char *p)
 401 {
 402         /*
 403          * Fail if we don't have enough data for the Hilscher pseudo-header.
 404          */
 405         ndo->ndo_protocol = "netanalyzer_if";
 406         if (h->caplen < 4) {
 407                 nd_print_trunc(ndo);
 408                 return (h->caplen);
 409         }
 410
 411         /* Skip the pseudo-header. */
 412         return (4 + ether_print(ndo, p + 4, h->len - 4, h->caplen - 4, NULL, NULL));
 413 }
 414
 415 /*
 416  * This is the top level routine of the printer.  'p' points
 417  * to the ether header of the packet, 'h->len' is the length
 418  * of the packet off the wire, and 'h->caplen' is the number
 419  * of bytes actually captured.
 420  *
 421  * This is for DLT_NETANALYZER_TRANSPARENT, which has a 4-byte
 422  * pseudo-header, a 7-byte Ethernet preamble, and a 1-byte Ethernet SOF
 423  * before the Ethernet header.
 424  */
 425 u_int
 426 netanalyzer_transparent_if_print(netdissect_options *ndo,
 427                                  const struct pcap_pkthdr *h,
 428                                  const u_char *p)
 429 {
 430         /*
 431          * Fail if we don't have enough data for the Hilscher pseudo-header,
 432          * preamble, and SOF.
 433          */
 434         ndo->ndo_protocol = "netanalyzer_transparent_if";
 435         if (h->caplen < 12) {
 436                 nd_print_trunc(ndo);
 437                 return (h->caplen);
 438         }
 439
 440         /* Skip the pseudo-header, preamble, and SOF. */
 441         return (12 + ether_print(ndo, p + 12, h->len - 12, h->caplen - 12, NULL, NULL));
 442 }
 443
 444 /*
 445  * Prints the packet payload, given an Ethernet type code for the payload's
 446  * protocol.
 447  *
 448  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 449  */
 450
 451 int
 452 ethertype_print(netdissect_options *ndo,
 453                 u_short ether_type, const u_char *p,
 454                 u_int length, u_int caplen,
 455                 const struct lladdr_info *src, const struct lladdr_info *dst)
 456 {
 457         switch (ether_type) {
 458
 459         case ETHERTYPE_IP:
 460                 ip_print(ndo, p, length);
 461                 return (1);
 462
 463         case ETHERTYPE_IPV6:
 464                 ip6_print(ndo, p, length);
 465                 return (1);
 466
 467         case ETHERTYPE_ARP:
 468         case ETHERTYPE_REVARP:
 469                 arp_print(ndo, p, length, caplen);
 470                 return (1);
 471
 472         case ETHERTYPE_DN:
 473                 decnet_print(ndo, p, length, caplen);
 474                 return (1);
 475
 476         case ETHERTYPE_ATALK:
 477                 if (ndo->ndo_vflag)
 478                         ND_PRINT("et1 ");
 479                 atalk_print(ndo, p, length);
 480                 return (1);
 481
 482         case ETHERTYPE_AARP:
 483                 aarp_print(ndo, p, length);
 484                 return (1);
 485
 486         case ETHERTYPE_IPX:
 487                 ND_PRINT("(NOV-ETHII) ");
 488                 ipx_print(ndo, p, length);
 489                 return (1);
 490
 491         case ETHERTYPE_ISO:
 492                 if (length == 0 || caplen == 0) {
 493                         ndo->ndo_protocol = "isoclns";
 494                         nd_print_trunc(ndo);
 495                         return (1);
 496                 }
 497                 isoclns_print(ndo, p + 1, length - 1);
 498                 return(1);
 499
 500         case ETHERTYPE_PPPOED:
 501         case ETHERTYPE_PPPOES:
 502         case ETHERTYPE_PPPOED2:
 503         case ETHERTYPE_PPPOES2:
 504                 pppoe_print(ndo, p, length);
 505                 return (1);
 506
 507         case ETHERTYPE_EAPOL:
 508                 eap_print(ndo, p, length);
 509                 return (1);
 510
 511         case ETHERTYPE_RRCP:
 512                 rrcp_print(ndo, p, length, src, dst);
 513                 return (1);
 514
 515         case ETHERTYPE_PPP:
 516                 if (length) {
 517                         ND_PRINT(": ");
 518                         ppp_print(ndo, p, length);
 519                 }
 520                 return (1);
 521
 522         case ETHERTYPE_MPCP:
 523                 mpcp_print(ndo, p, length);
 524                 return (1);
 525
 526         case ETHERTYPE_SLOW:
 527                 slow_print(ndo, p, length);
 528                 return (1);
 529
 530         case ETHERTYPE_CFM:
 531         case ETHERTYPE_CFM_OLD:
 532                 cfm_print(ndo, p, length);
 533                 return (1);
 534
 535         case ETHERTYPE_LLDP:
 536                 lldp_print(ndo, p, length);
 537                 return (1);
 538
 539         case ETHERTYPE_NSH:
 540                 nsh_print(ndo, p, length);
 541                 return (1);
 542
 543         case ETHERTYPE_LOOPBACK:
 544                 loopback_print(ndo, p, length);
 545                 return (1);
 546
 547         case ETHERTYPE_MPLS:
 548         case ETHERTYPE_MPLS_MULTI:
 549                 mpls_print(ndo, p, length);
 550                 return (1);
 551
 552         case ETHERTYPE_TIPC:
 553                 tipc_print(ndo, p, length, caplen);
 554                 return (1);
 555
 556         case ETHERTYPE_MS_NLB_HB:
 557                 msnlb_print(ndo, p);
 558                 return (1);
 559
 560         case ETHERTYPE_GEONET_OLD:
 561         case ETHERTYPE_GEONET:
 562                 geonet_print(ndo, p, length, src);
 563                 return (1);
 564
 565         case ETHERTYPE_CALM_FAST:
 566                 calm_fast_print(ndo, p, length, src);
 567                 return (1);
 568
 569         case ETHERTYPE_AOE:
 570                 aoe_print(ndo, p, length);
 571                 return (1);
 572
 573         case ETHERTYPE_LAT:
 574         case ETHERTYPE_SCA:
 575         case ETHERTYPE_MOPRC:
 576         case ETHERTYPE_MOPDL:
 577         case ETHERTYPE_IEEE1905_1:
 578                 /* default_print for now */
 579         default:
 580                 return (0);
 581         }
 582 }