contrib/tcpdump/print-llc.c

   1 /*
   2  * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
   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  * Code by Matt Thomas, Digital Equipment Corporation
  22  *      with an awful lot of hacking by Jeffrey Mogul, DECWRL
  23  */
  24
  25 /* \summary: IEEE 802.2 LLC printer */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include <config.h>
  29 #endif
  30
  31 #include "netdissect-stdinc.h"
  32
  33 #include "netdissect.h"
  34 #include "addrtoname.h"
  35 #include "extract.h"
  36
  37 #include "llc.h"
  38 #include "ethertype.h"
  39 #include "oui.h"
  40
  41 static const struct tok llc_values[] = {
  42         { LLCSAP_NULL,     "Null" },
  43         { LLCSAP_GLOBAL,   "Global" },
  44         { LLCSAP_8021B_I,  "802.1B I" },
  45         { LLCSAP_8021B_G,  "802.1B G" },
  46         { LLCSAP_IP,       "IP" },
  47         { LLCSAP_SNA,      "SNA" },
  48         { LLCSAP_PROWAYNM, "ProWay NM" },
  49         { LLCSAP_8021D,    "STP" },
  50         { LLCSAP_RS511,    "RS511" },
  51         { LLCSAP_ISO8208,  "ISO8208" },
  52         { LLCSAP_PROWAY,   "ProWay" },
  53         { LLCSAP_SNAP,     "SNAP" },
  54         { LLCSAP_IPX,      "IPX" },
  55         { LLCSAP_NETBEUI,  "NetBeui" },
  56         { LLCSAP_ISONS,    "OSI" },
  57         { 0,               NULL },
  58 };
  59
  60 static const struct tok llc_cmd_values[] = {
  61         { LLC_UI,       "ui" },
  62         { LLC_TEST,     "test" },
  63         { LLC_XID,      "xid" },
  64         { LLC_UA,       "ua" },
  65         { LLC_DISC,     "disc" },
  66         { LLC_DM,       "dm" },
  67         { LLC_SABME,    "sabme" },
  68         { LLC_FRMR,     "frmr" },
  69         { 0,            NULL }
  70 };
  71
  72 static const struct tok llc_flag_values[] = {
  73         { 0, "Command" },
  74         { LLC_GSAP, "Response" },
  75         { LLC_U_POLL, "Poll" },
  76         { LLC_GSAP|LLC_U_POLL, "Final" },
  77         { LLC_IS_POLL, "Poll" },
  78         { LLC_GSAP|LLC_IS_POLL, "Final" },
  79         { 0, NULL }
  80 };
  81
  82
  83 static const struct tok llc_ig_flag_values[] = {
  84         { 0, "Individual" },
  85         { LLC_IG, "Group" },
  86         { 0, NULL }
  87 };
  88
  89
  90 static const struct tok llc_supervisory_values[] = {
  91         { 0, "Receiver Ready" },
  92         { 1, "Receiver not Ready" },
  93         { 2, "Reject" },
  94         { 0,             NULL }
  95 };
  96
  97
  98 static const struct tok cisco_values[] = {
  99         { PID_CISCO_CDP, "CDP" },
 100         { PID_CISCO_VTP, "VTP" },
 101         { PID_CISCO_DTP, "DTP" },
 102         { PID_CISCO_UDLD, "UDLD" },
 103         { PID_CISCO_PVST, "PVST" },
 104         { PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
 105         { 0,             NULL }
 106 };
 107
 108 static const struct tok bridged_values[] = {
 109         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 110         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 111         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 112         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 113         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 114         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 115         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 116         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 117         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 118         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 119         { PID_RFC2684_BPDU,        "BPDU" },
 120         { 0,                       NULL },
 121 };
 122
 123 static const struct tok null_values[] = {
 124         { 0,             NULL }
 125 };
 126
 127 struct oui_tok {
 128         uint32_t        oui;
 129         const struct tok *tok;
 130 };
 131
 132 static const struct oui_tok oui_to_tok[] = {
 133         { OUI_ENCAP_ETHER, ethertype_values },
 134         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 135         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 136         { OUI_CISCO, cisco_values },
 137         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 138         { 0, NULL }
 139 };
 140
 141 /*
 142  * If we printed information about the payload, returns the length of the LLC
 143  * header, plus the length of any SNAP header following it.
 144  *
 145  * Otherwise (for example, if the packet has unknown SAPs or has a SNAP
 146  * header with an unknown OUI/PID combination), returns the *negative*
 147  * of that value.
 148  */
 149 int
 150 llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 151           const struct lladdr_info *src, const struct lladdr_info *dst)
 152 {
 153         uint8_t dsap_field, dsap, ssap_field, ssap;
 154         uint16_t control;
 155         int hdrlen;
 156         int is_u;
 157
 158         ndo->ndo_protocol = "llc";
 159         if (caplen < 3) {
 160                 nd_print_trunc(ndo);
 161                 ND_DEFAULTPRINT((const u_char *)p, caplen);
 162                 return (caplen);
 163         }
 164         if (length < 3) {
 165                 nd_print_trunc(ndo);
 166                 ND_DEFAULTPRINT((const u_char *)p, caplen);
 167                 return (length);
 168         }
 169
 170         dsap_field = GET_U_1(p);
 171         ssap_field = GET_U_1(p + 1);
 172
 173         /*
 174          * OK, what type of LLC frame is this?  The length
 175          * of the control field depends on that - I frames
 176          * have a two-byte control field, and U frames have
 177          * a one-byte control field.
 178          */
 179         control = GET_U_1(p + 2);
 180         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 181                 /*
 182                  * U frame.
 183                  */
 184                 is_u = 1;
 185                 hdrlen = 3;     /* DSAP, SSAP, 1-byte control field */
 186         } else {
 187                 /*
 188                  * The control field in I and S frames is
 189                  * 2 bytes...
 190                  */
 191                 if (caplen < 4) {
 192                         nd_print_trunc(ndo);
 193                         ND_DEFAULTPRINT((const u_char *)p, caplen);
 194                         return (caplen);
 195                 }
 196                 if (length < 4) {
 197                         nd_print_trunc(ndo);
 198                         ND_DEFAULTPRINT((const u_char *)p, caplen);
 199                         return (length);
 200                 }
 201
 202                 /*
 203                  * ...and is little-endian.
 204                  */
 205                 control = GET_LE_U_2(p + 2);
 206                 is_u = 0;
 207                 hdrlen = 4;     /* DSAP, SSAP, 2-byte control field */
 208         }
 209
 210         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 211                 /*
 212                  * This is an Ethernet_802.3 IPX frame; it has an
 213                  * 802.3 header (i.e., an Ethernet header where the
 214                  * type/length field is <= MAX_ETHERNET_LENGTH_VAL,
 215                  * i.e. it's a length field, not a type field), but
 216                  * has no 802.2 header - the IPX packet starts right
 217                  * after the Ethernet header, with a signature of two
 218                  * bytes of 0xFF (which is LLCSAP_GLOBAL).
 219                  *
 220                  * (It might also have been an Ethernet_802.3 IPX at
 221                  * one time, but got bridged onto another network,
 222                  * such as an 802.11 network; this has appeared in at
 223                  * least one capture file.)
 224                  */
 225
 226             if (ndo->ndo_eflag)
 227                 ND_PRINT("IPX 802.3: ");
 228
 229             ipx_print(ndo, p, length);
 230             return (0);         /* no LLC header */
 231         }
 232
 233         dsap = dsap_field & ~LLC_IG;
 234         ssap = ssap_field & ~LLC_GSAP;
 235
 236         if (ndo->ndo_eflag) {
 237                 ND_PRINT("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 238                        tok2str(llc_values, "Unknown", dsap),
 239                        dsap,
 240                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 241                        tok2str(llc_values, "Unknown", ssap),
 242                        ssap,
 243                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
 244
 245                 if (is_u) {
 246                         ND_PRINT(", ctrl 0x%02x: ", control);
 247                 } else {
 248                         ND_PRINT(", ctrl 0x%04x: ", control);
 249                 }
 250         }
 251
 252         /*
 253          * Skip LLC header.
 254          */
 255         p += hdrlen;
 256         length -= hdrlen;
 257         caplen -= hdrlen;
 258
 259         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 260             && control == LLC_UI) {
 261                 /*
 262                  * XXX - what *is* the right bridge pad value here?
 263                  * Does anybody ever bridge one form of LAN traffic
 264                  * over a networking type that uses 802.2 LLC?
 265                  */
 266                 if (!snap_print(ndo, p, length, caplen, src, dst, 2)) {
 267                         /*
 268                          * Unknown packet type; tell our caller, by
 269                          * returning a negative value, so they
 270                          * can print the raw packet.
 271                          */
 272                         return (-(hdrlen + 5)); /* include LLC and SNAP header */
 273                 } else
 274                         return (hdrlen + 5);    /* include LLC and SNAP header */
 275         }
 276
 277         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 278             control == LLC_UI) {
 279                 stp_print(ndo, p, length);
 280                 return (hdrlen);
 281         }
 282
 283         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 284             control == LLC_UI) {
 285                 /*
 286                  * This is an RFC 948-style IP packet, with
 287                  * an 802.3 header and an 802.2 LLC header
 288                  * with the source and destination SAPs being
 289                  * the IP SAP.
 290                  */
 291                 ip_print(ndo, p, length);
 292                 return (hdrlen);
 293         }
 294
 295         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 296             control == LLC_UI) {
 297                 /*
 298                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 299                  * header and an 802.2 LLC header with the source and
 300                  * destination SAPs being the IPX SAP.
 301                  */
 302                 if (ndo->ndo_eflag)
 303                         ND_PRINT("IPX 802.2: ");
 304
 305                 ipx_print(ndo, p, length);
 306                 return (hdrlen);
 307         }
 308
 309 #ifdef ENABLE_SMB
 310         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 311             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 312                 /*
 313                  * we don't actually have a full netbeui parser yet, but the
 314                  * smb parser can handle many smb-in-netbeui packets, which
 315                  * is very useful, so we call that
 316                  *
 317                  * We don't call it for S frames, however, just I frames
 318                  * (which are frames that don't have the low-order bit,
 319                  * LLC_S_FMT, set in the first byte of the control field)
 320                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 321                  */
 322                 netbeui_print(ndo, control, p, length);
 323                 return (hdrlen);
 324         }
 325 #endif
 326         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 327             && control == LLC_UI) {
 328                 isoclns_print(ndo, p, length);
 329                 return (hdrlen);
 330         }
 331
 332         if (!ndo->ndo_eflag) {
 333                 if (ssap == dsap) {
 334                         if (src == NULL || dst == NULL)
 335                                 ND_PRINT("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 336                         else
 337                                 ND_PRINT("%s > %s %s ",
 338                                                 (src->addr_string)(ndo, src->addr),
 339                                                 (dst->addr_string)(ndo, dst->addr),
 340                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 341                 } else {
 342                         if (src == NULL || dst == NULL)
 343                                 ND_PRINT("%s > %s ",
 344                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 345                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 346                         else
 347                                 ND_PRINT("%s %s > %s %s ",
 348                                         (src->addr_string)(ndo, src->addr),
 349                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 350                                         (dst->addr_string)(ndo, dst->addr),
 351                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 352                 }
 353         }
 354
 355         if (is_u) {
 356                 ND_PRINT("Unnumbered, %s, Flags [%s], length %u",
 357                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 358                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 359                        length + hdrlen);
 360
 361                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 362                         if (length == 0) {
 363                                 /*
 364                                  * XID with no payload.
 365                                  * This could, for example, be an SNA
 366                                  * "short form" XID.
 367                                  */
 368                                 return (hdrlen);
 369                         }
 370                         if (caplen < 1) {
 371                                 nd_print_trunc(ndo);
 372                                 if (caplen > 0)
 373                                         ND_DEFAULTPRINT((const u_char *)p, caplen);
 374                                 return (hdrlen);
 375                         }
 376                         if (GET_U_1(p) == LLC_XID_FI) {
 377                                 if (caplen < 3 || length < 3) {
 378                                         nd_print_trunc(ndo);
 379                                         if (caplen > 0)
 380                                                 ND_DEFAULTPRINT((const u_char *)p, caplen);
 381                                 } else
 382                                         ND_PRINT(": %02x %02x",
 383                                                   GET_U_1(p + 1),
 384                                                   GET_U_1(p + 2));
 385                                 return (hdrlen);
 386                         }
 387                 }
 388         } else {
 389                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 390                         ND_PRINT("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 391                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 392                                 LLC_IS_NR(control),
 393                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 394                                 length + hdrlen);
 395                         return (hdrlen);        /* no payload to print */
 396                 } else {
 397                         ND_PRINT("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 398                                 LLC_I_NS(control),
 399                                 LLC_IS_NR(control),
 400                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 401                                 length + hdrlen);
 402                 }
 403         }
 404         return (-hdrlen);
 405 }
 406
 407 static const struct tok *
 408 oui_to_struct_tok(uint32_t orgcode)
 409 {
 410         const struct tok *tok = null_values;
 411         const struct oui_tok *otp;
 412
 413         for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 414                 if (otp->oui == orgcode) {
 415                         tok = otp->tok;
 416                         break;
 417                 }
 418         }
 419         return (tok);
 420 }
 421
 422 int
 423 snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 424         const struct lladdr_info *src, const struct lladdr_info *dst,
 425         u_int bridge_pad)
 426 {
 427         uint32_t orgcode;
 428         u_short et;
 429         int ret;
 430
 431         ndo->ndo_protocol = "snap";
 432         ND_TCHECK_5(p);
 433         if (caplen < 5 || length < 5)
 434                 goto trunc;
 435         orgcode = GET_BE_U_3(p);
 436         et = GET_BE_U_2(p + 3);
 437
 438         if (ndo->ndo_eflag) {
 439                 /*
 440                  * Somebody's already printed the MAC addresses, if there
 441                  * are any, so just print the SNAP header, not the MAC
 442                  * addresses.
 443                  */
 444                 ND_PRINT("oui %s (0x%06x), %s %s (0x%04x), length %u: ",
 445                      tok2str(oui_values, "Unknown", orgcode),
 446                      orgcode,
 447                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 448                      tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
 449                      et, length - 5);
 450         }
 451         p += 5;
 452         length -= 5;
 453         caplen -= 5;
 454
 455         switch (orgcode) {
 456         case OUI_ENCAP_ETHER:
 457         case OUI_CISCO_90:
 458                 /*
 459                  * This is an encapsulated Ethernet packet,
 460                  * or a packet bridged by some piece of
 461                  * Cisco hardware; the protocol ID is
 462                  * an Ethernet protocol type.
 463                  */
 464                 ret = ethertype_print(ndo, et, p, length, caplen, src, dst);
 465                 if (ret)
 466                         return (ret);
 467                 break;
 468
 469         case OUI_APPLETALK:
 470                 if (et == ETHERTYPE_ATALK) {
 471                         /*
 472                          * No, I have no idea why Apple used one
 473                          * of their own OUIs, rather than
 474                          * 0x000000, and an Ethernet packet
 475                          * type, for Appletalk data packets,
 476                          * but used 0x000000 and an Ethernet
 477                          * packet type for AARP packets.
 478                          */
 479                         ret = ethertype_print(ndo, et, p, length, caplen, src, dst);
 480                         if (ret)
 481                                 return (ret);
 482                 }
 483                 break;
 484
 485         case OUI_CISCO:
 486                 switch (et) {
 487                 case PID_CISCO_CDP:
 488                         cdp_print(ndo, p, length);
 489                         return (1);
 490                 case PID_CISCO_DTP:
 491                         dtp_print(ndo, p, length);
 492                         return (1);
 493                 case PID_CISCO_UDLD:
 494                         udld_print(ndo, p, length);
 495                         return (1);
 496                 case PID_CISCO_VTP:
 497                         vtp_print(ndo, p, length);
 498                         return (1);
 499                 case PID_CISCO_PVST:
 500                 case PID_CISCO_VLANBRIDGE:
 501                         stp_print(ndo, p, length);
 502                         return (1);
 503                 default:
 504                         break;
 505                 }
 506                 break;
 507
 508         case OUI_RFC2684:
 509                 switch (et) {
 510
 511                 case PID_RFC2684_ETH_FCS:
 512                 case PID_RFC2684_ETH_NOFCS:
 513                         /*
 514                          * XXX - remove the last two bytes for
 515                          * PID_RFC2684_ETH_FCS?
 516                          */
 517                         /*
 518                          * Skip the padding.
 519                          */
 520                         ND_TCHECK_LEN(p, bridge_pad);
 521                         caplen -= bridge_pad;
 522                         length -= bridge_pad;
 523                         p += bridge_pad;
 524
 525                         /*
 526                          * What remains is an Ethernet packet.
 527                          */
 528                         ether_print(ndo, p, length, caplen, NULL, NULL);
 529                         return (1);
 530
 531                 case PID_RFC2684_802_5_FCS:
 532                 case PID_RFC2684_802_5_NOFCS:
 533                         /*
 534                          * XXX - remove the last two bytes for
 535                          * PID_RFC2684_ETH_FCS?
 536                          */
 537                         /*
 538                          * Skip the padding, but not the Access
 539                          * Control field.
 540                          */
 541                         ND_TCHECK_LEN(p, bridge_pad);
 542                         caplen -= bridge_pad;
 543                         length -= bridge_pad;
 544                         p += bridge_pad;
 545
 546                         /*
 547                          * What remains is an 802.5 Token Ring
 548                          * packet.
 549                          */
 550                         token_print(ndo, p, length, caplen);
 551                         return (1);
 552
 553                 case PID_RFC2684_FDDI_FCS:
 554                 case PID_RFC2684_FDDI_NOFCS:
 555                         /*
 556                          * XXX - remove the last two bytes for
 557                          * PID_RFC2684_ETH_FCS?
 558                          */
 559                         /*
 560                          * Skip the padding.
 561                          */
 562                         ND_TCHECK_LEN(p, bridge_pad + 1);
 563                         caplen -= bridge_pad + 1;
 564                         length -= bridge_pad + 1;
 565                         p += bridge_pad + 1;
 566
 567                         /*
 568                          * What remains is an FDDI packet.
 569                          */
 570                         fddi_print(ndo, p, length, caplen);
 571                         return (1);
 572
 573                 case PID_RFC2684_BPDU:
 574                         stp_print(ndo, p, length);
 575                         return (1);
 576                 }
 577         }
 578         if (!ndo->ndo_eflag) {
 579                 /*
 580                  * Nobody printed the link-layer addresses, so print them, if
 581                  * we have any.
 582                  */
 583                 if (src != NULL && dst != NULL) {
 584                         ND_PRINT("%s > %s ",
 585                                 (src->addr_string)(ndo, src->addr),
 586                                 (dst->addr_string)(ndo, dst->addr));
 587                 }
 588                 /*
 589                  * Print the SNAP header, but if the OUI is 000000, don't
 590                  * bother printing it, and report the PID as being an
 591                  * ethertype.
 592                  */
 593                 if (orgcode == 0x000000) {
 594                         ND_PRINT("SNAP, ethertype %s (0x%04x), length %u: ",
 595                              tok2str(ethertype_values, "Unknown", et),
 596                              et, length);
 597                 } else {
 598                         ND_PRINT("SNAP, oui %s (0x%06x), pid %s (0x%04x), length %u: ",
 599                              tok2str(oui_values, "Unknown", orgcode),
 600                              orgcode,
 601                              tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
 602                              et, length);
 603                 }
 604         }
 605         return (0);
 606
 607 trunc:
 608         nd_print_trunc(ndo);
 609         return (1);
 610 }