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     { ETHERTYPE_PTP,            "PTP" },
 104     { ETHERTYPE_ARISTA,         "Arista Vendor Specific Protocol" },
 105     { 0, NULL}
 106 };
 107
 108 static void
 109 ether_addresses_print(netdissect_options *ndo, const u_char *src,
 110                       const u_char *dst)
 111 {
 112         ND_PRINT("%s > %s, ",
 113                  GET_ETHERADDR_STRING(src), GET_ETHERADDR_STRING(dst));
 114 }
 115
 116 static void
 117 ether_type_print(netdissect_options *ndo, uint16_t type)
 118 {
 119         if (!ndo->ndo_qflag)
 120                 ND_PRINT("ethertype %s (0x%04x)",
 121                          tok2str(ethertype_values, "Unknown", type), type);
 122         else
 123                 ND_PRINT("%s",
 124                          tok2str(ethertype_values, "Unknown Ethertype (0x%04x)", type));
 125 }
 126
 127 /*
 128  * Common code for printing Ethernet frames.
 129  *
 130  * It can handle Ethernet headers with extra tag information inserted
 131  * after the destination and source addresses, as is inserted by some
 132  * switch chips, and extra encapsulation header information before
 133  * printing Ethernet header information (such as a LANE ID for ATM LANE).
 134  */
 135 static u_int
 136 ether_print_common(netdissect_options *ndo, const u_char *p, u_int length,
 137     u_int caplen,
 138     void (*print_switch_tag)(netdissect_options *ndo, const u_char *),
 139     u_int switch_tag_len,
 140     void (*print_encap_header)(netdissect_options *ndo, const u_char *),
 141     const u_char *encap_header_arg)
 142 {
 143         const struct ether_header *ehp;
 144         u_int orig_length;
 145         u_int hdrlen;
 146         u_short length_type;
 147         int printed_length;
 148         int llc_hdrlen;
 149         struct lladdr_info src, dst;
 150
 151         if (caplen < ETHER_HDRLEN + switch_tag_len) {
 152                 nd_print_trunc(ndo);
 153                 return (caplen);
 154         }
 155         if (length < ETHER_HDRLEN + switch_tag_len) {
 156                 nd_print_trunc(ndo);
 157                 return (length);
 158         }
 159
 160         if (print_encap_header != NULL)
 161                 (*print_encap_header)(ndo, encap_header_arg);
 162
 163         orig_length = length;
 164
 165         /*
 166          * Get the source and destination addresses, skip past them,
 167          * and print them if we're printing the link-layer header.
 168          */
 169         ehp = (const struct ether_header *)p;
 170         src.addr = ehp->ether_shost;
 171         src.addr_string = etheraddr_string;
 172         dst.addr = ehp->ether_dhost;
 173         dst.addr_string = etheraddr_string;
 174
 175         length -= 2*MAC_ADDR_LEN;
 176         caplen -= 2*MAC_ADDR_LEN;
 177         p += 2*MAC_ADDR_LEN;
 178         hdrlen = 2*MAC_ADDR_LEN;
 179
 180         if (ndo->ndo_eflag)
 181                 ether_addresses_print(ndo, src.addr, dst.addr);
 182
 183         /*
 184          * Print the switch tag, if we have one, and skip past it.
 185          */
 186         if (print_switch_tag != NULL)
 187                 (*print_switch_tag)(ndo, p);
 188
 189         length -= switch_tag_len;
 190         caplen -= switch_tag_len;
 191         p += switch_tag_len;
 192         hdrlen += switch_tag_len;
 193
 194         /*
 195          * Get the length/type field, skip past it, and print it
 196          * if we're printing the link-layer header.
 197          */
 198 recurse:
 199         length_type = GET_BE_U_2(p);
 200
 201         length -= 2;
 202         caplen -= 2;
 203         p += 2;
 204         hdrlen += 2;
 205
 206         /*
 207          * Process VLAN tag types.
 208          */
 209         printed_length = 0;
 210         while (length_type == ETHERTYPE_8021Q  ||
 211                 length_type == ETHERTYPE_8021Q9100 ||
 212                 length_type == ETHERTYPE_8021Q9200 ||
 213                 length_type == ETHERTYPE_8021QinQ) {
 214                 /*
 215                  * It has a VLAN tag.
 216                  * Print VLAN information, and then go back and process
 217                  * the enclosed type field.
 218                  */
 219                 if (caplen < 4) {
 220                         ndo->ndo_protocol = "vlan";
 221                         nd_print_trunc(ndo);
 222                         return (hdrlen + caplen);
 223                 }
 224                 if (length < 4) {
 225                         ndo->ndo_protocol = "vlan";
 226                         nd_print_trunc(ndo);
 227                         return (hdrlen + length);
 228                 }
 229                 if (ndo->ndo_eflag) {
 230                         uint16_t tag = GET_BE_U_2(p);
 231
 232                         ether_type_print(ndo, length_type);
 233                         if (!printed_length) {
 234                                 ND_PRINT(", length %u: ", orig_length);
 235                                 printed_length = 1;
 236                         } else
 237                                 ND_PRINT(", ");
 238                         ND_PRINT("%s, ", ieee8021q_tci_string(tag));
 239                 }
 240
 241                 length_type = GET_BE_U_2(p + 2);
 242                 p += 4;
 243                 length -= 4;
 244                 caplen -= 4;
 245                 hdrlen += 4;
 246         }
 247
 248         /*
 249          * We now have the final length/type field.
 250          */
 251         if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
 252                 /*
 253                  * It's a length field, containing the length of the
 254                  * remaining payload; use it as such, as long as
 255                  * it's not too large (bigger than the actual payload).
 256                  */
 257                 if (length_type < length) {
 258                         length = length_type;
 259                         if (caplen > length)
 260                                 caplen = length;
 261                 }
 262
 263                 /*
 264                  * Cut off the snapshot length to the end of the
 265                  * payload.
 266                  */
 267                 nd_push_snapend(ndo, p + length);
 268
 269                 if (ndo->ndo_eflag) {
 270                         ND_PRINT("802.3");
 271                         if (!printed_length)
 272                                 ND_PRINT(", length %u: ", length);
 273                 }
 274
 275                 /*
 276                  * An LLC header follows the length.  Print that and
 277                  * higher layers.
 278                  */
 279                 llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
 280                 if (llc_hdrlen < 0) {
 281                         /* packet type not known, print raw packet */
 282                         if (!ndo->ndo_suppress_default_print)
 283                                 ND_DEFAULTPRINT(p, caplen);
 284                         llc_hdrlen = -llc_hdrlen;
 285                 }
 286                 hdrlen += llc_hdrlen;
 287                 nd_pop_packet_info(ndo);
 288         } else if (length_type == ETHERTYPE_JUMBO) {
 289                 /*
 290                  * It's a type field, with the type for Alteon jumbo frames.
 291                  * See
 292                  *
 293                  *      https://tools.ietf.org/html/draft-ietf-isis-ext-eth-01
 294                  *
 295                  * which indicates that, following the type field,
 296                  * there's an LLC header and payload.
 297                  */
 298                 /* Try to print the LLC-layer header & higher layers */
 299                 llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst);
 300                 if (llc_hdrlen < 0) {
 301                         /* packet type not known, print raw packet */
 302                         if (!ndo->ndo_suppress_default_print)
 303                                 ND_DEFAULTPRINT(p, caplen);
 304                         llc_hdrlen = -llc_hdrlen;
 305                 }
 306                 hdrlen += llc_hdrlen;
 307         } else if (length_type == ETHERTYPE_ARISTA) {
 308                 if (caplen < 2) {
 309                         ND_PRINT("[|arista]");
 310                         return (hdrlen + caplen);
 311                 }
 312                 if (length < 2) {
 313                         ND_PRINT("[|arista]");
 314                         return (hdrlen + length);
 315                 }
 316                 ether_type_print(ndo, length_type);
 317                 ND_PRINT(", length %u: ", orig_length);
 318                 int bytesConsumed = arista_ethertype_print(ndo, p, length);
 319                 if (bytesConsumed > 0) {
 320                         p += bytesConsumed;
 321                         length -= bytesConsumed;
 322                         caplen -= bytesConsumed;
 323                         hdrlen += bytesConsumed;
 324                         goto recurse;
 325                 } else {
 326                         /* subtype/version not known, print raw packet */
 327                         if (!ndo->ndo_eflag && length_type > MAX_ETHERNET_LENGTH_VAL) {
 328                                 ether_addresses_print(ndo, src.addr, dst.addr);
 329                                 ether_type_print(ndo, length_type);
 330                                 ND_PRINT(", length %u: ", orig_length);
 331                         }
 332                          if (!ndo->ndo_suppress_default_print)
 333                                  ND_DEFAULTPRINT(p, caplen);
 334                 }
 335         } else {
 336                 /*
 337                  * It's a type field with some other value.
 338                  */
 339                 if (ndo->ndo_eflag) {
 340                         ether_type_print(ndo, length_type);
 341                         if (!printed_length)
 342                                 ND_PRINT(", length %u: ", orig_length);
 343                         else
 344                                 ND_PRINT(", ");
 345                 }
 346                 if (ethertype_print(ndo, length_type, p, length, caplen, &src, &dst) == 0) {
 347                         /* type not known, print raw packet */
 348                         if (!ndo->ndo_eflag) {
 349                                 /*
 350                                  * We didn't print the full link-layer
 351                                  * header, as -e wasn't specified, so
 352                                  * print only the source and destination
 353                                  * MAC addresses and the final Ethernet
 354                                  * type.
 355                                  */
 356                                 ether_addresses_print(ndo, src.addr, dst.addr);
 357                                 ether_type_print(ndo, length_type);
 358                                 ND_PRINT(", length %u: ", orig_length);
 359                         }
 360
 361                         if (!ndo->ndo_suppress_default_print)
 362                                 ND_DEFAULTPRINT(p, caplen);
 363                 }
 364         }
 365         return (hdrlen);
 366 }
 367
 368 /*
 369  * Print an Ethernet frame while specyfing a non-standard Ethernet header
 370  * length.
 371  * This might be encapsulated within another frame; we might be passed
 372  * a pointer to a function that can print header information for that
 373  * frame's protocol, and an argument to pass to that function.
 374  *
 375  * FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
 376  */
 377 u_int
 378 ether_print_switch_tag(netdissect_options *ndo, const u_char *p, u_int length,
 379     u_int caplen,
 380     void (*print_switch_tag)(netdissect_options *, const u_char *),
 381     u_int switch_tag_len)
 382 {
 383         return (ether_print_common(ndo, p, length, caplen, print_switch_tag,
 384                                    switch_tag_len, NULL, NULL));
 385 }
 386
 387 /*
 388  * Print an Ethernet frame.
 389  * This might be encapsulated within another frame; we might be passed
 390  * a pointer to a function that can print header information for that
 391  * frame's protocol, and an argument to pass to that function.
 392  *
 393  * FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
 394  */
 395 u_int
 396 ether_print(netdissect_options *ndo,
 397             const u_char *p, u_int length, u_int caplen,
 398             void (*print_encap_header)(netdissect_options *ndo, const u_char *),
 399             const u_char *encap_header_arg)
 400 {
 401         ndo->ndo_protocol = "ether";
 402         return (ether_print_common(ndo, p, length, caplen, NULL, 0,
 403                                     print_encap_header, encap_header_arg));
 404 }
 405
 406 /*
 407  * This is the top level routine of the printer.  'p' points
 408  * to the ether header of the packet, 'h->len' is the length
 409  * of the packet off the wire, and 'h->caplen' is the number
 410  * of bytes actually captured.
 411  */
 412 u_int
 413 ether_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
 414                const u_char *p)
 415 {
 416         ndo->ndo_protocol = "ether_if";
 417         return (ether_print(ndo, p, h->len, h->caplen, NULL, NULL));
 418 }
 419
 420 /*
 421  * This is the top level routine of the printer.  'p' points
 422  * to the ether header of the packet, 'h->len' is the length
 423  * of the packet off the wire, and 'h->caplen' is the number
 424  * of bytes actually captured.
 425  *
 426  * This is for DLT_NETANALYZER, which has a 4-byte pseudo-header
 427  * before the Ethernet header.
 428  */
 429 u_int
 430 netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
 431                      const u_char *p)
 432 {
 433         /*
 434          * Fail if we don't have enough data for the Hilscher pseudo-header.
 435          */
 436         ndo->ndo_protocol = "netanalyzer_if";
 437         if (h->caplen < 4) {
 438                 nd_print_trunc(ndo);
 439                 return (h->caplen);
 440         }
 441
 442         /* Skip the pseudo-header. */
 443         return (4 + ether_print(ndo, p + 4, h->len - 4, h->caplen - 4, NULL, NULL));
 444 }
 445
 446 /*
 447  * This is the top level routine of the printer.  'p' points
 448  * to the ether header of the packet, 'h->len' is the length
 449  * of the packet off the wire, and 'h->caplen' is the number
 450  * of bytes actually captured.
 451  *
 452  * This is for DLT_NETANALYZER_TRANSPARENT, which has a 4-byte
 453  * pseudo-header, a 7-byte Ethernet preamble, and a 1-byte Ethernet SOF
 454  * before the Ethernet header.
 455  */
 456 u_int
 457 netanalyzer_transparent_if_print(netdissect_options *ndo,
 458                                  const struct pcap_pkthdr *h,
 459                                  const u_char *p)
 460 {
 461         /*
 462          * Fail if we don't have enough data for the Hilscher pseudo-header,
 463          * preamble, and SOF.
 464          */
 465         ndo->ndo_protocol = "netanalyzer_transparent_if";
 466         if (h->caplen < 12) {
 467                 nd_print_trunc(ndo);
 468                 return (h->caplen);
 469         }
 470
 471         /* Skip the pseudo-header, preamble, and SOF. */
 472         return (12 + ether_print(ndo, p + 12, h->len - 12, h->caplen - 12, NULL, NULL));
 473 }
 474
 475 /*
 476  * Prints the packet payload, given an Ethernet type code for the payload's
 477  * protocol.
 478  *
 479  * Returns non-zero if it can do so, zero if the ethertype is unknown.
 480  */
 481
 482 int
 483 ethertype_print(netdissect_options *ndo,
 484                 u_short ether_type, const u_char *p,
 485                 u_int length, u_int caplen,
 486                 const struct lladdr_info *src, const struct lladdr_info *dst)
 487 {
 488         switch (ether_type) {
 489
 490         case ETHERTYPE_IP:
 491                 ip_print(ndo, p, length);
 492                 return (1);
 493
 494         case ETHERTYPE_IPV6:
 495                 ip6_print(ndo, p, length);
 496                 return (1);
 497
 498         case ETHERTYPE_ARP:
 499         case ETHERTYPE_REVARP:
 500                 arp_print(ndo, p, length, caplen);
 501                 return (1);
 502
 503         case ETHERTYPE_DN:
 504                 decnet_print(ndo, p, length, caplen);
 505                 return (1);
 506
 507         case ETHERTYPE_ATALK:
 508                 if (ndo->ndo_vflag)
 509                         ND_PRINT("et1 ");
 510                 atalk_print(ndo, p, length);
 511                 return (1);
 512
 513         case ETHERTYPE_AARP:
 514                 aarp_print(ndo, p, length);
 515                 return (1);
 516
 517         case ETHERTYPE_IPX:
 518                 ND_PRINT("(NOV-ETHII) ");
 519                 ipx_print(ndo, p, length);
 520                 return (1);
 521
 522         case ETHERTYPE_ISO:
 523                 if (length == 0 || caplen == 0) {
 524                         ndo->ndo_protocol = "isoclns";
 525                         nd_print_trunc(ndo);
 526                         return (1);
 527                 }
 528                 isoclns_print(ndo, p + 1, length - 1);
 529                 return(1);
 530
 531         case ETHERTYPE_PPPOED:
 532         case ETHERTYPE_PPPOES:
 533         case ETHERTYPE_PPPOED2:
 534         case ETHERTYPE_PPPOES2:
 535                 pppoe_print(ndo, p, length);
 536                 return (1);
 537
 538         case ETHERTYPE_EAPOL:
 539                 eap_print(ndo, p, length);
 540                 return (1);
 541
 542         case ETHERTYPE_RRCP:
 543                 rrcp_print(ndo, p, length, src, dst);
 544                 return (1);
 545
 546         case ETHERTYPE_PPP:
 547                 if (length) {
 548                         ND_PRINT(": ");
 549                         ppp_print(ndo, p, length);
 550                 }
 551                 return (1);
 552
 553         case ETHERTYPE_MPCP:
 554                 mpcp_print(ndo, p, length);
 555                 return (1);
 556
 557         case ETHERTYPE_SLOW:
 558                 slow_print(ndo, p, length);
 559                 return (1);
 560
 561         case ETHERTYPE_CFM:
 562         case ETHERTYPE_CFM_OLD:
 563                 cfm_print(ndo, p, length);
 564                 return (1);
 565
 566         case ETHERTYPE_LLDP:
 567                 lldp_print(ndo, p, length);
 568                 return (1);
 569
 570         case ETHERTYPE_NSH:
 571                 nsh_print(ndo, p, length);
 572                 return (1);
 573
 574         case ETHERTYPE_LOOPBACK:
 575                 loopback_print(ndo, p, length);
 576                 return (1);
 577
 578         case ETHERTYPE_MPLS:
 579         case ETHERTYPE_MPLS_MULTI:
 580                 mpls_print(ndo, p, length);
 581                 return (1);
 582
 583         case ETHERTYPE_TIPC:
 584                 tipc_print(ndo, p, length, caplen);
 585                 return (1);
 586
 587         case ETHERTYPE_MS_NLB_HB:
 588                 msnlb_print(ndo, p);
 589                 return (1);
 590
 591         case ETHERTYPE_GEONET_OLD:
 592         case ETHERTYPE_GEONET:
 593                 geonet_print(ndo, p, length, src);
 594                 return (1);
 595
 596         case ETHERTYPE_CALM_FAST:
 597                 calm_fast_print(ndo, p, length, src);
 598                 return (1);
 599
 600         case ETHERTYPE_AOE:
 601                 aoe_print(ndo, p, length);
 602                 return (1);
 603
 604         case ETHERTYPE_PTP:
 605                 ptp_print(ndo, p, length);
 606                 return (1);
 607
 608         case ETHERTYPE_LAT:
 609         case ETHERTYPE_SCA:
 610         case ETHERTYPE_MOPRC:
 611         case ETHERTYPE_MOPDL:
 612         case ETHERTYPE_IEEE1905_1:
 613                 /* default_print for now */
 614         default:
 615                 return (0);
 616         }
 617 }