The Tcpdump Group git mirrors - tcpdump/blob - 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 #define NETDISSECT_REWORKED
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <tcpdump-stdinc.h>
  31
  32 #include "interface.h"
  33 #include "addrtoname.h"
  34 #include "extract.h"                    /* must come after interface.h */
  35
  36 #include "llc.h"
  37 #include "ethertype.h"
  38 #include "oui.h"
  39
  40 static const struct tok llc_values[] = {
  41         { LLCSAP_NULL,     "Null" },
  42         { LLCSAP_GLOBAL,   "Global" },
  43         { LLCSAP_8021B_I,  "802.1B I" },
  44         { LLCSAP_8021B_G,  "802.1B G" },
  45         { LLCSAP_IP,       "IP" },
  46         { LLCSAP_SNA,      "SNA" },
  47         { LLCSAP_PROWAYNM, "ProWay NM" },
  48         { LLCSAP_8021D,    "STP" },
  49         { LLCSAP_RS511,    "RS511" },
  50         { LLCSAP_ISO8208,  "ISO8208" },
  51         { LLCSAP_PROWAY,   "ProWay" },
  52         { LLCSAP_SNAP,     "SNAP" },
  53         { LLCSAP_IPX,      "IPX" },
  54         { LLCSAP_NETBEUI,  "NetBeui" },
  55         { LLCSAP_ISONS,    "OSI" },
  56         { 0,               NULL },
  57 };
  58
  59 static const struct tok llc_cmd_values[] = {
  60         { LLC_UI,       "ui" },
  61         { LLC_TEST,     "test" },
  62         { LLC_XID,      "xid" },
  63         { LLC_UA,       "ua" },
  64         { LLC_DISC,     "disc" },
  65         { LLC_DM,       "dm" },
  66         { LLC_SABME,    "sabme" },
  67         { LLC_FRMR,     "frmr" },
  68         { 0,            NULL }
  69 };
  70
  71 static const struct tok llc_flag_values[] = {
  72         { 0, "Command" },
  73         { LLC_GSAP, "Response" },
  74         { LLC_U_POLL, "Poll" },
  75         { LLC_GSAP|LLC_U_POLL, "Final" },
  76         { LLC_IS_POLL, "Poll" },
  77         { LLC_GSAP|LLC_IS_POLL, "Final" },
  78         { 0, NULL }
  79 };
  80
  81
  82 static const struct tok llc_ig_flag_values[] = {
  83         { 0, "Individual" },
  84         { LLC_IG, "Group" },
  85         { 0, NULL }
  86 };
  87
  88
  89 static const struct tok llc_supervisory_values[] = {
  90         { 0, "Receiver Ready" },
  91         { 1, "Receiver not Ready" },
  92         { 2, "Reject" },
  93         { 0,             NULL }
  94 };
  95
  96
  97 static const struct tok cisco_values[] = {
  98         { PID_CISCO_CDP, "CDP" },
  99         { PID_CISCO_VTP, "VTP" },
 100         { PID_CISCO_DTP, "DTP" },
 101         { PID_CISCO_UDLD, "UDLD" },
 102         { PID_CISCO_PVST, "PVST" },
 103         { PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
 104         { 0,             NULL }
 105 };
 106
 107 static const struct tok bridged_values[] = {
 108         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 109         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 110         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 111         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 112         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 113         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 114         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 115         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 116         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 117         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 118         { PID_RFC2684_BPDU,        "BPDU" },
 119         { 0,                       NULL },
 120 };
 121
 122 static const struct tok null_values[] = {
 123         { 0,             NULL }
 124 };
 125
 126 struct oui_tok {
 127         uint32_t        oui;
 128         const struct tok *tok;
 129 };
 130
 131 static const struct oui_tok oui_to_tok[] = {
 132         { OUI_ENCAP_ETHER, ethertype_values },
 133         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 134         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 135         { OUI_CISCO, cisco_values },
 136         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 137         { 0, NULL }
 138 };
 139
 140 /*
 141  * Returns non-zero IFF it succeeds in printing the header
 142  */
 143 int
 144 llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 145           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 146 {
 147         uint8_t dsap_field, dsap, ssap_field, ssap;
 148         uint16_t control;
 149         int is_u;
 150         register int ret;
 151
 152         *extracted_ethertype = 0;
 153
 154         if (caplen < 3 || length < 3) {
 155                 ND_PRINT((ndo, "[|llc]"));
 156                 ND_DEFAULTPRINT((u_char *)p, caplen);
 157                 return (1);
 158         }
 159
 160         dsap_field = *p;
 161         ssap_field = *(p + 1);
 162
 163         /*
 164          * OK, what type of LLC frame is this?  The length
 165          * of the control field depends on that - I frames
 166          * have a two-byte control field, and U frames have
 167          * a one-byte control field.
 168          */
 169         control = *(p + 2);
 170         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 171                 /*
 172                  * U frame.
 173                  */
 174                 is_u = 1;
 175         } else {
 176                 /*
 177                  * The control field in I and S frames is
 178                  * 2 bytes...
 179                  */
 180                 if (caplen < 4 || length < 4) {
 181                         ND_PRINT((ndo, "[|llc]"));
 182                         ND_DEFAULTPRINT((u_char *)p, caplen);
 183                         return (1);
 184                 }
 185
 186                 /*
 187                  * ...and is little-endian.
 188                  */
 189                 control = EXTRACT_LE_16BITS(p + 2);
 190                 is_u = 0;
 191         }
 192
 193         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 194                 /*
 195                  * This is an Ethernet_802.3 IPX frame; it has an
 196                  * 802.3 header (i.e., an Ethernet header where the
 197                  * type/length field is <= ETHERMTU, i.e. it's a length
 198                  * field, not a type field), but has no 802.2 header -
 199                  * the IPX packet starts right after the Ethernet header,
 200                  * with a signature of two bytes of 0xFF (which is
 201                  * LLCSAP_GLOBAL).
 202                  *
 203                  * (It might also have been an Ethernet_802.3 IPX at
 204                  * one time, but got bridged onto another network,
 205                  * such as an 802.11 network; this has appeared in at
 206                  * least one capture file.)
 207                  */
 208
 209             if (ndo->ndo_eflag)
 210                 ND_PRINT((ndo, "IPX 802.3: "));
 211
 212             ipx_print(ndo, p, length);
 213             return (1);
 214         }
 215
 216         dsap = dsap_field & ~LLC_IG;
 217         ssap = ssap_field & ~LLC_GSAP;
 218
 219         if (ndo->ndo_eflag) {
 220                 ND_PRINT((ndo, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 221                        tok2str(llc_values, "Unknown", dsap),
 222                        dsap,
 223                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 224                        tok2str(llc_values, "Unknown", ssap),
 225                        ssap,
 226                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP)));
 227
 228                 if (is_u) {
 229                         ND_PRINT((ndo, ", ctrl 0x%02x: ", control));
 230                 } else {
 231                         ND_PRINT((ndo, ", ctrl 0x%04x: ", control));
 232                 }
 233         }
 234
 235         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 236             control == LLC_UI) {
 237                 stp_print(ndo, p+3, length-3);
 238                 return (1);
 239         }
 240
 241         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 242             control == LLC_UI) {
 243                 if (caplen < 4 || length < 4) {
 244                         ND_PRINT((ndo, "[|llc]"));
 245                         ND_DEFAULTPRINT((u_char *)p, caplen);
 246                         return (1);
 247                 }
 248                 ip_print(ndo, p+4, length-4);
 249                 return (1);
 250         }
 251
 252         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 253             control == LLC_UI) {
 254                 /*
 255                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 256                  * header and an 802.2 LLC header with the source and
 257                  * destination SAPs being the IPX SAP.
 258                  *
 259                  * Skip DSAP, LSAP, and control field.
 260                  */
 261                 if (ndo->ndo_eflag)
 262                         ND_PRINT((ndo, "IPX 802.2: "));
 263
 264                 ipx_print(ndo, p+3, length-3);
 265                 return (1);
 266         }
 267
 268 #ifdef TCPDUMP_DO_SMB
 269         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 270             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 271                 /*
 272                  * we don't actually have a full netbeui parser yet, but the
 273                  * smb parser can handle many smb-in-netbeui packets, which
 274                  * is very useful, so we call that
 275                  *
 276                  * We don't call it for S frames, however, just I frames
 277                  * (which are frames that don't have the low-order bit,
 278                  * LLC_S_FMT, set in the first byte of the control field)
 279                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 280                  */
 281
 282                 /*
 283                  * Skip the LLC header.
 284                  */
 285                 if (is_u) {
 286                         p += 3;
 287                         length -= 3;
 288                 } else {
 289                         p += 4;
 290                         length -= 4;
 291                 }
 292                 netbeui_print(ndo, control, p, length);
 293                 return (1);
 294         }
 295 #endif
 296         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 297             && control == LLC_UI) {
 298                 isoclns_print(ndo, p + 3, length - 3, caplen - 3);
 299                 return (1);
 300         }
 301
 302         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 303             && control == LLC_UI) {
 304                 /*
 305                  * XXX - what *is* the right bridge pad value here?
 306                  * Does anybody ever bridge one form of LAN traffic
 307                  * over a networking type that uses 802.2 LLC?
 308                  */
 309                 ret = snap_print(ndo, p+3, length-3, caplen-3, 2);
 310                 if (ret)
 311                         return (ret);
 312         }
 313
 314         if (!ndo->ndo_eflag) {
 315                 if (ssap == dsap) {
 316                         if (esrc == NULL || edst == NULL)
 317                                 ND_PRINT((ndo, "%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 318                         else
 319                                 ND_PRINT((ndo, "%s > %s %s ",
 320                                                 etheraddr_string(ndo, esrc),
 321                                                 etheraddr_string(ndo, edst),
 322                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 323                 } else {
 324                         if (esrc == NULL || edst == NULL)
 325                                 ND_PRINT((ndo, "%s > %s ",
 326                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 327                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 328                         else
 329                                 ND_PRINT((ndo, "%s %s > %s %s ",
 330                                         etheraddr_string(ndo, esrc),
 331                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 332                                         etheraddr_string(ndo, edst),
 333                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 334                 }
 335         }
 336
 337         if (is_u) {
 338                 ND_PRINT((ndo, "Unnumbered, %s, Flags [%s], length %u",
 339                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 340                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 341                        length));
 342
 343                 p += 3;
 344
 345                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 346                         if (*p == LLC_XID_FI) {
 347                                 ND_PRINT((ndo, ": %02x %02x", p[1], p[2]));
 348                         }
 349                 }
 350         } else {
 351                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 352                         ND_PRINT((ndo, "Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 353                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 354                                 LLC_IS_NR(control),
 355                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 356                                 length));
 357                 } else {
 358                         ND_PRINT((ndo, "Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 359                                 LLC_I_NS(control),
 360                                 LLC_IS_NR(control),
 361                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 362                                 length));
 363                 }
 364         }
 365         return(1);
 366 }
 367
 368 int
 369 snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
 370 {
 371         uint32_t orgcode;
 372         register u_short et;
 373         register int ret;
 374
 375         ND_TCHECK2(*p, 5);
 376         if (caplen < 5 || length < 5)
 377                 goto trunc;
 378         orgcode = EXTRACT_24BITS(p);
 379         et = EXTRACT_16BITS(p + 3);
 380
 381         if (ndo->ndo_eflag) {
 382                 const struct tok *tok = null_values;
 383                 const struct oui_tok *otp;
 384
 385                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 386                         if (otp->oui == orgcode) {
 387                                 tok = otp->tok;
 388                                 break;
 389                         }
 390                 }
 391                 ND_PRINT((ndo, "oui %s (0x%06x), %s %s (0x%04x): ",
 392                      tok2str(oui_values, "Unknown", orgcode),
 393                      orgcode,
 394                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 395                      tok2str(tok, "Unknown", et),
 396                      et));
 397         }
 398         p += 5;
 399         length -= 5;
 400         caplen -= 5;
 401
 402         switch (orgcode) {
 403         case OUI_ENCAP_ETHER:
 404         case OUI_CISCO_90:
 405                 /*
 406                  * This is an encapsulated Ethernet packet,
 407                  * or a packet bridged by some piece of
 408                  * Cisco hardware; the protocol ID is
 409                  * an Ethernet protocol type.
 410                  */
 411                 ret = ethertype_print(ndo, et, p, length, caplen);
 412                 if (ret)
 413                         return (ret);
 414                 break;
 415
 416         case OUI_APPLETALK:
 417                 if (et == ETHERTYPE_ATALK) {
 418                         /*
 419                          * No, I have no idea why Apple used one
 420                          * of their own OUIs, rather than
 421                          * 0x000000, and an Ethernet packet
 422                          * type, for Appletalk data packets,
 423                          * but used 0x000000 and an Ethernet
 424                          * packet type for AARP packets.
 425                          */
 426                         ret = ethertype_print(ndo, et, p, length, caplen);
 427                         if (ret)
 428                                 return (ret);
 429                 }
 430                 break;
 431
 432         case OUI_CISCO:
 433                 switch (et) {
 434                 case PID_CISCO_CDP:
 435                         cdp_print(ndo, p, length, caplen);
 436                         return (1);
 437                 case PID_CISCO_DTP:
 438                         dtp_print(ndo, p, length);
 439                         return (1);
 440                 case PID_CISCO_UDLD:
 441                         udld_print(ndo, p, length);
 442                         return (1);
 443                 case PID_CISCO_VTP:
 444                         vtp_print(ndo, p, length);
 445                         return (1);
 446                 case PID_CISCO_PVST:
 447                 case PID_CISCO_VLANBRIDGE:
 448                         stp_print(ndo, p, length);
 449                         return (1);
 450                 default:
 451                         break;
 452                 }
 453                 break;
 454
 455         case OUI_RFC2684:
 456                 switch (et) {
 457
 458                 case PID_RFC2684_ETH_FCS:
 459                 case PID_RFC2684_ETH_NOFCS:
 460                         /*
 461                          * XXX - remove the last two bytes for
 462                          * PID_RFC2684_ETH_FCS?
 463                          */
 464                         /*
 465                          * Skip the padding.
 466                          */
 467                         ND_TCHECK2(*p, bridge_pad);
 468                         caplen -= bridge_pad;
 469                         length -= bridge_pad;
 470                         p += bridge_pad;
 471
 472                         /*
 473                          * What remains is an Ethernet packet.
 474                          */
 475                         ether_print(ndo, p, length, caplen, NULL, NULL);
 476                         return (1);
 477
 478                 case PID_RFC2684_802_5_FCS:
 479                 case PID_RFC2684_802_5_NOFCS:
 480                         /*
 481                          * XXX - remove the last two bytes for
 482                          * PID_RFC2684_ETH_FCS?
 483                          */
 484                         /*
 485                          * Skip the padding, but not the Access
 486                          * Control field.
 487                          */
 488                         ND_TCHECK2(*p, bridge_pad);
 489                         caplen -= bridge_pad;
 490                         length -= bridge_pad;
 491                         p += bridge_pad;
 492
 493                         /*
 494                          * What remains is an 802.5 Token Ring
 495                          * packet.
 496                          */
 497                         token_print(ndo, p, length, caplen);
 498                         return (1);
 499
 500                 case PID_RFC2684_FDDI_FCS:
 501                 case PID_RFC2684_FDDI_NOFCS:
 502                         /*
 503                          * XXX - remove the last two bytes for
 504                          * PID_RFC2684_ETH_FCS?
 505                          */
 506                         /*
 507                          * Skip the padding.
 508                          */
 509                         ND_TCHECK2(*p, bridge_pad + 1);
 510                         caplen -= bridge_pad + 1;
 511                         length -= bridge_pad + 1;
 512                         p += bridge_pad + 1;
 513
 514                         /*
 515                          * What remains is an FDDI packet.
 516                          */
 517                         fddi_print(ndo, p, length, caplen);
 518                         return (1);
 519
 520                 case PID_RFC2684_BPDU:
 521                         stp_print(ndo, p, length);
 522                         return (1);
 523                 }
 524         }
 525         return (0);
 526
 527 trunc:
 528         ND_PRINT((ndo, "[|snap]"));
 529         return (1);
 530 }
 531
 532
 533 /*
 534  * Local Variables:
 535  * c-style: whitesmith
 536  * c-basic-offset: 8
 537  * End:
 538  */