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 1.69 2005-12-01 18:05:12 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_ig_flag_values[] = {
  90         { 0, "Individual" },
  91         { LLC_IG, "Group" },
  92         { 0, NULL }
  93 };
  94
  95
  96 static const struct tok llc_supervisory_values[] = {
  97         { 0, "Receiver Ready" },
  98         { 1, "Receiver not Ready" },
  99         { 2, "Reject" },
 100         { 0,             NULL }
 101 };
 102
 103
 104 static const struct tok cisco_values[] = {
 105         { PID_CISCO_CDP, "CDP" },
 106         { 0,             NULL }
 107 };
 108
 109 static const struct tok bridged_values[] = {
 110         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 111         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 112         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 113         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 114         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 115         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 116         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 117         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 118         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 119         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 120         { PID_RFC2684_BPDU,        "BPDU" },
 121         { 0,                       NULL },
 122 };
 123
 124 struct oui_tok {
 125         u_int32_t       oui;
 126         const struct tok *tok;
 127 };
 128
 129 static const struct oui_tok oui_to_tok[] = {
 130         { OUI_ENCAP_ETHER, ethertype_values },
 131         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 132         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 133         { OUI_CISCO, cisco_values },
 134         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 135         { 0, NULL }
 136 };
 137
 138 /*
 139  * Returns non-zero IFF it succeeds in printing the header
 140  */
 141 int
 142 llc_print(const u_char *p, u_int length, u_int caplen,
 143           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 144 {
 145         u_int8_t dsap_field, dsap, ssap_field, ssap;
 146         u_int16_t control;
 147         int is_u;
 148         register int ret;
 149
 150         *extracted_ethertype = 0;
 151
 152         if (caplen < 3) {
 153                 (void)printf("[|llc]");
 154                 default_print((u_char *)p, caplen);
 155                 return(0);
 156         }
 157
 158         dsap_field = *p;
 159         ssap_field = *(p + 1);
 160
 161         /*
 162          * OK, what type of LLC frame is this?  The length
 163          * of the control field depends on that - I frames
 164          * have a two-byte control field, and U frames have
 165          * a one-byte control field.
 166          */
 167         control = *(p + 2);
 168         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 169                 /*
 170                  * U frame.
 171                  */
 172                 is_u = 1;
 173         } else {
 174                 /*
 175                  * The control field in I and S frames is
 176                  * 2 bytes...
 177                  */
 178                 if (caplen < 4) {
 179                         (void)printf("[|llc]");
 180                         default_print((u_char *)p, caplen);
 181                         return(0);
 182                 }
 183
 184                 /*
 185                  * ...and is little-endian.
 186                  */
 187                 control = EXTRACT_LE_16BITS(p + 2);
 188                 is_u = 0;
 189         }
 190
 191         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 192                 /*
 193                  * This is an Ethernet_802.3 IPX frame; it has an
 194                  * 802.3 header (i.e., an Ethernet header where the
 195                  * type/length field is <= ETHERMTU, i.e. it's a length
 196                  * field, not a type field), but has no 802.2 header -
 197                  * the IPX packet starts right after the Ethernet header,
 198                  * with a signature of two bytes of 0xFF (which is
 199                  * LLCSAP_GLOBAL).
 200                  *
 201                  * (It might also have been an Ethernet_802.3 IPX at
 202                  * one time, but got bridged onto another network,
 203                  * such as an 802.11 network; this has appeared in at
 204                  * least one capture file.)
 205                  */
 206
 207             if (eflag)
 208                 printf("IPX 802.3: ");
 209
 210             ipx_print(p, length);
 211             return (1);
 212         }
 213
 214         dsap = dsap_field & ~LLC_IG;
 215         ssap = ssap_field & ~LLC_GSAP;
 216
 217         if (eflag) {
 218                 printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 219                        tok2str(llc_values, "Unknown", dsap),
 220                        dsap,
 221                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 222                        tok2str(llc_values, "Unknown", ssap),
 223                        ssap,
 224                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
 225
 226                 if (is_u) {
 227                         printf(", ctrl 0x%02x: ", control);
 228                 } else {
 229                         printf(", ctrl 0x%04x: ", control);
 230                 }
 231         }
 232
 233         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 234             control == LLC_UI) {
 235                 stp_print(p+3, length-3);
 236                 return (1);
 237         }
 238
 239         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 240             control == LLC_UI) {
 241                 ip_print(gndo, p+4, length-4);
 242                 return (1);
 243         }
 244
 245         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 246             control == LLC_UI) {
 247                 /*
 248                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 249                  * header and an 802.2 LLC header with the source and
 250                  * destination SAPs being the IPX SAP.
 251                  *
 252                  * Skip DSAP, LSAP, and control field.
 253                  */
 254                 if (eflag)
 255                         printf("IPX 802.2: ");
 256
 257                 ipx_print(p+3, length-3);
 258                 return (1);
 259         }
 260
 261 #ifdef TCPDUMP_DO_SMB
 262         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 263             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 264                 /*
 265                  * we don't actually have a full netbeui parser yet, but the
 266                  * smb parser can handle many smb-in-netbeui packets, which
 267                  * is very useful, so we call that
 268                  *
 269                  * We don't call it for S frames, however, just I frames
 270                  * (which are frames that don't have the low-order bit,
 271                  * LLC_S_FMT, set in the first byte of the control field)
 272                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 273                  */
 274
 275                 /*
 276                  * Skip the LLC header.
 277                  */
 278                 if (is_u) {
 279                         p += 3;
 280                         length -= 3;
 281                         caplen -= 3;
 282                 } else {
 283                         p += 4;
 284                         length -= 4;
 285                         caplen -= 4;
 286                 }
 287                 netbeui_print(control, p, length);
 288                 return (1);
 289         }
 290 #endif
 291         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 292             && control == LLC_UI) {
 293                 isoclns_print(p + 3, length - 3, caplen - 3);
 294                 return (1);
 295         }
 296
 297         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 298             && control == LLC_UI) {
 299                 /*
 300                  * XXX - what *is* the right bridge pad value here?
 301                  * Does anybody ever bridge one form of LAN traffic
 302                  * over a networking type that uses 802.2 LLC?
 303                  */
 304                 ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
 305                     2);
 306                 if (ret)
 307                         return (ret);
 308         }
 309
 310         if (!eflag) {
 311                 if (ssap == dsap) {
 312                         if (esrc == NULL || edst == NULL)
 313                                 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 314                         else
 315                                 (void)printf("%s > %s %s ",
 316                                                 etheraddr_string(esrc),
 317                                                 etheraddr_string(edst),
 318                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 319                 } else {
 320                         if (esrc == NULL || edst == NULL)
 321                                 (void)printf("%s > %s ",
 322                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 323                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 324                         else
 325                                 (void)printf("%s %s > %s %s ",
 326                                         etheraddr_string(esrc),
 327                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 328                                         etheraddr_string(edst),
 329                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 330                 }
 331         }
 332
 333         if (is_u) {
 334                 printf("Unnumbered, %s, Flags [%s], length %u",
 335                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 336                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 337                        length);
 338
 339                 p += 3;
 340                 length -= 3;
 341                 caplen -= 3;
 342
 343                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 344                         if (*p == LLC_XID_FI) {
 345                                 printf(": %02x %02x", p[1], p[2]);
 346                                 p += 3;
 347                                 length -= 3;
 348                                 caplen -= 3;
 349                         }
 350                 }
 351         } else {
 352                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 353                         (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 354                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 355                                 LLC_IS_NR(control),
 356                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 357                                 length);
 358                 } else {
 359                         (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 360                                 LLC_I_NS(control),
 361                                 LLC_IS_NR(control),
 362                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 363                                 length);
 364                 }
 365                 p += 4;
 366                 length -= 4;
 367                 caplen -= 4;
 368         }
 369         return(1);
 370 }
 371
 372 int
 373 snap_print(const u_char *p, u_int length, u_int caplen,
 374     u_short *extracted_ethertype, u_int bridge_pad)
 375 {
 376         u_int32_t orgcode;
 377         register u_short et;
 378         register int ret;
 379
 380         TCHECK2(*p, 5);
 381         orgcode = EXTRACT_24BITS(p);
 382         et = EXTRACT_16BITS(p + 3);
 383
 384         if (eflag) {
 385                 const struct tok *tok = NULL;
 386                 const struct oui_tok *otp;
 387
 388                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 389                         if (otp->oui == orgcode) {
 390                                 tok = otp->tok;
 391                                 break;
 392                         }
 393                 }
 394                 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 395                      tok2str(oui_values, "Unknown", orgcode),
 396                      orgcode,
 397                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 398                      tok2str(tok, "Unknown", et),
 399                      et);
 400         }
 401         p += 5;
 402         length -= 5;
 403         caplen -= 5;
 404
 405         switch (orgcode) {
 406         case OUI_ENCAP_ETHER:
 407         case OUI_CISCO_90:
 408                 /*
 409                  * This is an encapsulated Ethernet packet,
 410                  * or a packet bridged by some piece of
 411                  * Cisco hardware; the protocol ID is
 412                  * an Ethernet protocol type.
 413                  */
 414                 ret = ether_encap_print(et, p, length, caplen,
 415                     extracted_ethertype);
 416                 if (ret)
 417                         return (ret);
 418                 break;
 419
 420         case OUI_APPLETALK:
 421                 if (et == ETHERTYPE_ATALK) {
 422                         /*
 423                          * No, I have no idea why Apple used one
 424                          * of their own OUIs, rather than
 425                          * 0x000000, and an Ethernet packet
 426                          * type, for Appletalk data packets,
 427                          * but used 0x000000 and an Ethernet
 428                          * packet type for AARP packets.
 429                          */
 430                         ret = ether_encap_print(et, p, length, caplen,
 431                             extracted_ethertype);
 432                         if (ret)
 433                                 return (ret);
 434                 }
 435                 break;
 436
 437         case OUI_CISCO:
 438                 if (et == PID_CISCO_CDP) {
 439                         cdp_print(p, length, caplen);
 440                         return (1);
 441                 }
 442                 break;
 443
 444         case OUI_RFC2684:
 445                 switch (et) {
 446
 447                 case PID_RFC2684_ETH_FCS:
 448                 case PID_RFC2684_ETH_NOFCS:
 449                         /*
 450                          * XXX - remove the last two bytes for
 451                          * PID_RFC2684_ETH_FCS?
 452                          */
 453                         /*
 454                          * Skip the padding.
 455                          */
 456                         TCHECK2(*p, bridge_pad);
 457                         caplen -= bridge_pad;
 458                         length -= bridge_pad;
 459                         p += bridge_pad;
 460
 461                         /*
 462                          * What remains is an Ethernet packet.
 463                          */
 464                         ether_print(p, length, caplen);
 465                         return (1);
 466
 467                 case PID_RFC2684_802_5_FCS:
 468                 case PID_RFC2684_802_5_NOFCS:
 469                         /*
 470                          * XXX - remove the last two bytes for
 471                          * PID_RFC2684_ETH_FCS?
 472                          */
 473                         /*
 474                          * Skip the padding, but not the Access
 475                          * Control field.
 476                          */
 477                         TCHECK2(*p, bridge_pad);
 478                         caplen -= bridge_pad;
 479                         length -= bridge_pad;
 480                         p += bridge_pad;
 481
 482                         /*
 483                          * What remains is an 802.5 Token Ring
 484                          * packet.
 485                          */
 486                         token_print(p, length, caplen);
 487                         return (1);
 488
 489                 case PID_RFC2684_FDDI_FCS:
 490                 case PID_RFC2684_FDDI_NOFCS:
 491                         /*
 492                          * XXX - remove the last two bytes for
 493                          * PID_RFC2684_ETH_FCS?
 494                          */
 495                         /*
 496                          * Skip the padding.
 497                          */
 498                         TCHECK2(*p, bridge_pad + 1);
 499                         caplen -= bridge_pad + 1;
 500                         length -= bridge_pad + 1;
 501                         p += bridge_pad + 1;
 502
 503                         /*
 504                          * What remains is an FDDI packet.
 505                          */
 506                         fddi_print(p, length, caplen);
 507                         return (1);
 508
 509                 case PID_RFC2684_BPDU:
 510                         stp_print(p, length);
 511                         return (1);
 512                 }
 513         }
 514         return (0);
 515
 516 trunc:
 517         (void)printf("[|snap]");
 518         return (1);
 519 }
 520
 521
 522 /*
 523  * Local Variables:
 524  * c-style: whitesmith
 525  * c-basic-offset: 8
 526  * End:
 527  */