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