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 #ifndef lint
  26 static const char rcsid[] _U_ =
  27     "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.68 2005-12-01 17:45:45 hannes Exp $";
  28 #endif
  29
  30 #ifdef HAVE_CONFIG_H
  31 #include "config.h"
  32 #endif
  33
  34 #include <tcpdump-stdinc.h>
  35
  36 #include <stdio.h>
  37 #include <string.h>
  38
  39 #include "interface.h"
  40 #include "addrtoname.h"
  41 #include "extract.h"                    /* must come after interface.h */
  42
  43 #include "llc.h"
  44 #include "ethertype.h"
  45 #include "oui.h"
  46
  47 static struct tok llc_values[] = {
  48         { LLCSAP_NULL,     "Null" },
  49         { LLCSAP_GLOBAL,   "Global" },
  50         { LLCSAP_8021B_I,  "802.1B I" },
  51         { LLCSAP_8021B_G,  "802.1B G" },
  52         { LLCSAP_IP,       "IP" },
  53         { LLCSAP_SNA,      "SNA" },
  54         { LLCSAP_PROWAYNM, "ProWay NM" },
  55         { LLCSAP_8021D,    "STP" },
  56         { LLCSAP_RS511,    "RS511" },
  57         { LLCSAP_ISO8208,  "ISO8208" },
  58         { LLCSAP_PROWAY,   "ProWay" },
  59         { LLCSAP_SNAP,     "SNAP" },
  60         { LLCSAP_IPX,      "IPX" },
  61         { LLCSAP_NETBEUI,  "NetBeui" },
  62         { LLCSAP_ISONS,    "OSI" },
  63         { 0,               NULL },
  64 };
  65
  66 static struct tok llc_cmd_values[] = {
  67         { LLC_UI,       "ui" },
  68         { LLC_TEST,     "test" },
  69         { LLC_XID,      "xid" },
  70         { LLC_UA,       "ua" },
  71         { LLC_DISC,     "disc" },
  72         { LLC_DM,       "dm" },
  73         { LLC_SABME,    "sabme" },
  74         { LLC_FRMR,     "frmr" },
  75         { 0,            NULL }
  76 };
  77
  78 static const struct tok llc_flag_values[] = {
  79         { 0, "Command" },
  80         { LLC_GSAP, "Response" },
  81         { LLC_U_POLL, "Poll" },
  82         { LLC_GSAP|LLC_U_POLL, "Final" },
  83         { LLC_IS_POLL, "Poll" },
  84         { LLC_GSAP|LLC_IS_POLL, "Final" },
  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         { 0,             NULL }
 100 };
 101
 102 static const struct tok bridged_values[] = {
 103         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 104         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 105         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 106         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 107         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 108         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 109         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 110         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 111         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 112         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 113         { PID_RFC2684_BPDU,        "BPDU" },
 114         { 0,                       NULL },
 115 };
 116
 117 struct oui_tok {
 118         u_int32_t       oui;
 119         const struct tok *tok;
 120 };
 121
 122 static const struct oui_tok oui_to_tok[] = {
 123         { OUI_ENCAP_ETHER, ethertype_values },
 124         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 125         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 126         { OUI_CISCO, cisco_values },
 127         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 128         { 0, NULL }
 129 };
 130
 131 /*
 132  * Returns non-zero IFF it succeeds in printing the header
 133  */
 134 int
 135 llc_print(const u_char *p, u_int length, u_int caplen,
 136           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 137 {
 138         u_int8_t dsap_field, dsap, ssap_field, ssap;
 139         u_int16_t control;
 140         int is_u;
 141         register int ret;
 142
 143         *extracted_ethertype = 0;
 144
 145         if (caplen < 3) {
 146                 (void)printf("[|llc]");
 147                 default_print((u_char *)p, caplen);
 148                 return(0);
 149         }
 150
 151         dsap_field = *p;
 152         ssap_field = *(p + 1);
 153
 154         /*
 155          * OK, what type of LLC frame is this?  The length
 156          * of the control field depends on that - I frames
 157          * have a two-byte control field, and U frames have
 158          * a one-byte control field.
 159          */
 160         control = *(p + 2);
 161         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 162                 /*
 163                  * U frame.
 164                  */
 165                 is_u = 1;
 166         } else {
 167                 /*
 168                  * The control field in I and S frames is
 169                  * 2 bytes...
 170                  */
 171                 if (caplen < 4) {
 172                         (void)printf("[|llc]");
 173                         default_print((u_char *)p, caplen);
 174                         return(0);
 175                 }
 176
 177                 /*
 178                  * ...and is little-endian.
 179                  */
 180                 control = EXTRACT_LE_16BITS(p + 2);
 181                 is_u = 0;
 182         }
 183
 184         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 185                 /*
 186                  * This is an Ethernet_802.3 IPX frame; it has an
 187                  * 802.3 header (i.e., an Ethernet header where the
 188                  * type/length field is <= ETHERMTU, i.e. it's a length
 189                  * field, not a type field), but has no 802.2 header -
 190                  * the IPX packet starts right after the Ethernet header,
 191                  * with a signature of two bytes of 0xFF (which is
 192                  * LLCSAP_GLOBAL).
 193                  *
 194                  * (It might also have been an Ethernet_802.3 IPX at
 195                  * one time, but got bridged onto another network,
 196                  * such as an 802.11 network; this has appeared in at
 197                  * least one capture file.)
 198                  */
 199
 200             if (eflag)
 201                 printf("IPX 802.3: ");
 202
 203             ipx_print(p, length);
 204             return (1);
 205         }
 206
 207         dsap = dsap_field & ~LLC_IG;
 208         ssap = ssap_field & ~LLC_GSAP;
 209
 210         if (eflag) {
 211                 printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x) %s",
 212                        tok2str(llc_values, "Unknown", dsap),
 213                        dsap,
 214                        tok2str(llc_values, "Unknown", ssap),
 215                        ssap,
 216                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
 217
 218                 if (is_u) {
 219                         printf(", ctrl 0x%02x: ", control);
 220                 } else {
 221                         printf(", ctrl 0x%04x: ", control);
 222                 }
 223         }
 224
 225         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 226             control == LLC_UI) {
 227                 stp_print(p+3, length-3);
 228                 return (1);
 229         }
 230
 231         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 232             control == LLC_UI) {
 233                 ip_print(gndo, p+4, length-4);
 234                 return (1);
 235         }
 236
 237         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 238             control == LLC_UI) {
 239                 /*
 240                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 241                  * header and an 802.2 LLC header with the source and
 242                  * destination SAPs being the IPX SAP.
 243                  *
 244                  * Skip DSAP, LSAP, and control field.
 245                  */
 246                 if (eflag)
 247                         printf("IPX 802.2: ");
 248
 249                 ipx_print(p+3, length-3);
 250                 return (1);
 251         }
 252
 253 #ifdef TCPDUMP_DO_SMB
 254         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 255             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 256                 /*
 257                  * we don't actually have a full netbeui parser yet, but the
 258                  * smb parser can handle many smb-in-netbeui packets, which
 259                  * is very useful, so we call that
 260                  *
 261                  * We don't call it for S frames, however, just I frames
 262                  * (which are frames that don't have the low-order bit,
 263                  * LLC_S_FMT, set in the first byte of the control field)
 264                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 265                  */
 266
 267                 /*
 268                  * Skip the LLC header.
 269                  */
 270                 if (is_u) {
 271                         p += 3;
 272                         length -= 3;
 273                         caplen -= 3;
 274                 } else {
 275                         p += 4;
 276                         length -= 4;
 277                         caplen -= 4;
 278                 }
 279                 netbeui_print(control, p, length);
 280                 return (1);
 281         }
 282 #endif
 283         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 284             && control == LLC_UI) {
 285                 isoclns_print(p + 3, length - 3, caplen - 3);
 286                 return (1);
 287         }
 288
 289         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 290             && control == LLC_UI) {
 291                 /*
 292                  * XXX - what *is* the right bridge pad value here?
 293                  * Does anybody ever bridge one form of LAN traffic
 294                  * over a networking type that uses 802.2 LLC?
 295                  */
 296                 ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
 297                     2);
 298                 if (ret)
 299                         return (ret);
 300         }
 301
 302         if (!eflag) {
 303                 if (ssap == dsap) {
 304                         if (esrc == NULL || edst == NULL)
 305                                 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 306                         else
 307                                 (void)printf("%s > %s %s ",
 308                                                 etheraddr_string(esrc),
 309                                                 etheraddr_string(edst),
 310                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 311                 } else {
 312                         if (esrc == NULL || edst == NULL)
 313                                 (void)printf("%s > %s ",
 314                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 315                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 316                         else
 317                                 (void)printf("%s %s > %s %s ",
 318                                         etheraddr_string(esrc),
 319                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 320                                         etheraddr_string(edst),
 321                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 322                 }
 323         }
 324
 325         if (is_u) {
 326                 printf("Unnumbered, %s, Flags [%s], length %u",
 327                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 328                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 329                        length);
 330
 331                 p += 3;
 332                 length -= 3;
 333                 caplen -= 3;
 334
 335                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 336                         if (*p == LLC_XID_FI) {
 337                                 printf(": %02x %02x", p[1], p[2]);
 338                                 p += 3;
 339                                 length -= 3;
 340                                 caplen -= 3;
 341                         }
 342                 }
 343         } else {
 344                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 345                         (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 346                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 347                                 LLC_IS_NR(control),
 348                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 349                                 length);
 350                 } else {
 351                         (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 352                                 LLC_I_NS(control),
 353                                 LLC_IS_NR(control),
 354                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 355                                 length);
 356                 }
 357                 p += 4;
 358                 length -= 4;
 359                 caplen -= 4;
 360         }
 361         return(1);
 362 }
 363
 364 int
 365 snap_print(const u_char *p, u_int length, u_int caplen,
 366     u_short *extracted_ethertype, u_int bridge_pad)
 367 {
 368         u_int32_t orgcode;
 369         register u_short et;
 370         register int ret;
 371
 372         TCHECK2(*p, 5);
 373         orgcode = EXTRACT_24BITS(p);
 374         et = EXTRACT_16BITS(p + 3);
 375
 376         if (eflag) {
 377                 const struct tok *tok = NULL;
 378                 const struct oui_tok *otp;
 379
 380                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 381                         if (otp->oui == orgcode) {
 382                                 tok = otp->tok;
 383                                 break;
 384                         }
 385                 }
 386                 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 387                      tok2str(oui_values, "Unknown", orgcode),
 388                      orgcode,
 389                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 390                      tok2str(tok, "Unknown", et),
 391                      et);
 392         }
 393         p += 5;
 394         length -= 5;
 395         caplen -= 5;
 396
 397         switch (orgcode) {
 398         case OUI_ENCAP_ETHER:
 399         case OUI_CISCO_90:
 400                 /*
 401                  * This is an encapsulated Ethernet packet,
 402                  * or a packet bridged by some piece of
 403                  * Cisco hardware; the protocol ID is
 404                  * an Ethernet protocol type.
 405                  */
 406                 ret = ether_encap_print(et, p, length, caplen,
 407                     extracted_ethertype);
 408                 if (ret)
 409                         return (ret);
 410                 break;
 411
 412         case OUI_APPLETALK:
 413                 if (et == ETHERTYPE_ATALK) {
 414                         /*
 415                          * No, I have no idea why Apple used one
 416                          * of their own OUIs, rather than
 417                          * 0x000000, and an Ethernet packet
 418                          * type, for Appletalk data packets,
 419                          * but used 0x000000 and an Ethernet
 420                          * packet type for AARP packets.
 421                          */
 422                         ret = ether_encap_print(et, p, length, caplen,
 423                             extracted_ethertype);
 424                         if (ret)
 425                                 return (ret);
 426                 }
 427                 break;
 428
 429         case OUI_CISCO:
 430                 if (et == PID_CISCO_CDP) {
 431                         cdp_print(p, length, caplen);
 432                         return (1);
 433                 }
 434                 break;
 435
 436         case OUI_RFC2684:
 437                 switch (et) {
 438
 439                 case PID_RFC2684_ETH_FCS:
 440                 case PID_RFC2684_ETH_NOFCS:
 441                         /*
 442                          * XXX - remove the last two bytes for
 443                          * PID_RFC2684_ETH_FCS?
 444                          */
 445                         /*
 446                          * Skip the padding.
 447                          */
 448                         TCHECK2(*p, bridge_pad);
 449                         caplen -= bridge_pad;
 450                         length -= bridge_pad;
 451                         p += bridge_pad;
 452
 453                         /*
 454                          * What remains is an Ethernet packet.
 455                          */
 456                         ether_print(p, length, caplen);
 457                         return (1);
 458
 459                 case PID_RFC2684_802_5_FCS:
 460                 case PID_RFC2684_802_5_NOFCS:
 461                         /*
 462                          * XXX - remove the last two bytes for
 463                          * PID_RFC2684_ETH_FCS?
 464                          */
 465                         /*
 466                          * Skip the padding, but not the Access
 467                          * Control field.
 468                          */
 469                         TCHECK2(*p, bridge_pad);
 470                         caplen -= bridge_pad;
 471                         length -= bridge_pad;
 472                         p += bridge_pad;
 473
 474                         /*
 475                          * What remains is an 802.5 Token Ring
 476                          * packet.
 477                          */
 478                         token_print(p, length, caplen);
 479                         return (1);
 480
 481                 case PID_RFC2684_FDDI_FCS:
 482                 case PID_RFC2684_FDDI_NOFCS:
 483                         /*
 484                          * XXX - remove the last two bytes for
 485                          * PID_RFC2684_ETH_FCS?
 486                          */
 487                         /*
 488                          * Skip the padding.
 489                          */
 490                         TCHECK2(*p, bridge_pad + 1);
 491                         caplen -= bridge_pad + 1;
 492                         length -= bridge_pad + 1;
 493                         p += bridge_pad + 1;
 494
 495                         /*
 496                          * What remains is an FDDI packet.
 497                          */
 498                         fddi_print(p, length, caplen);
 499                         return (1);
 500
 501                 case PID_RFC2684_BPDU:
 502                         stp_print(p, length);
 503                         return (1);
 504                 }
 505         }
 506         return (0);
 507
 508 trunc:
 509         (void)printf("[|snap]");
 510         return (1);
 511 }
 512
 513
 514 /*
 515  * Local Variables:
 516  * c-style: whitesmith
 517  * c-basic-offset: 8
 518  * End:
 519  */