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