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 1.61.2.9 2006-01-17 17:44:46 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 static const struct tok null_values[] = {
 125         { 0,             NULL }
 126 };
 127
 128 struct oui_tok {
 129         u_int32_t       oui;
 130         const struct tok *tok;
 131 };
 132
 133 static const struct oui_tok oui_to_tok[] = {
 134         { OUI_ENCAP_ETHER, ethertype_values },
 135         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 136         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 137         { OUI_CISCO, cisco_values },
 138         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 139         { 0, NULL }
 140 };
 141
 142 /*
 143  * Returns non-zero IFF it succeeds in printing the header
 144  */
 145 int
 146 llc_print(const u_char *p, u_int length, u_int caplen,
 147           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 148 {
 149         u_int8_t dsap_field, dsap, ssap_field, ssap;
 150         u_int16_t control;
 151         int is_u;
 152         register int ret;
 153
 154         *extracted_ethertype = 0;
 155
 156         if (caplen < 3) {
 157                 (void)printf("[|llc]");
 158                 default_print((u_char *)p, caplen);
 159                 return(0);
 160         }
 161
 162         dsap_field = *p;
 163         ssap_field = *(p + 1);
 164
 165         /*
 166          * OK, what type of LLC frame is this?  The length
 167          * of the control field depends on that - I frames
 168          * have a two-byte control field, and U frames have
 169          * a one-byte control field.
 170          */
 171         control = *(p + 2);
 172         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 173                 /*
 174                  * U frame.
 175                  */
 176                 is_u = 1;
 177         } else {
 178                 /*
 179                  * The control field in I and S frames is
 180                  * 2 bytes...
 181                  */
 182                 if (caplen < 4) {
 183                         (void)printf("[|llc]");
 184                         default_print((u_char *)p, caplen);
 185                         return(0);
 186                 }
 187
 188                 /*
 189                  * ...and is little-endian.
 190                  */
 191                 control = EXTRACT_LE_16BITS(p + 2);
 192                 is_u = 0;
 193         }
 194
 195         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 196                 /*
 197                  * This is an Ethernet_802.3 IPX frame; it has an
 198                  * 802.3 header (i.e., an Ethernet header where the
 199                  * type/length field is <= ETHERMTU, i.e. it's a length
 200                  * field, not a type field), but has no 802.2 header -
 201                  * the IPX packet starts right after the Ethernet header,
 202                  * with a signature of two bytes of 0xFF (which is
 203                  * LLCSAP_GLOBAL).
 204                  *
 205                  * (It might also have been an Ethernet_802.3 IPX at
 206                  * one time, but got bridged onto another network,
 207                  * such as an 802.11 network; this has appeared in at
 208                  * least one capture file.)
 209                  */
 210
 211             if (eflag)
 212                 printf("IPX 802.3: ");
 213
 214             ipx_print(p, length);
 215             return (1);
 216         }
 217
 218         dsap = dsap_field & ~LLC_IG;
 219         ssap = ssap_field & ~LLC_GSAP;
 220
 221         if (eflag) {
 222                 printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 223                        tok2str(llc_values, "Unknown", dsap),
 224                        dsap,
 225                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 226                        tok2str(llc_values, "Unknown", ssap),
 227                        ssap,
 228                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
 229
 230                 if (is_u) {
 231                         printf(", ctrl 0x%02x: ", control);
 232                 } else {
 233                         printf(", ctrl 0x%04x: ", control);
 234                 }
 235         }
 236
 237         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 238             control == LLC_UI) {
 239                 stp_print(p+3, length-3);
 240                 return (1);
 241         }
 242
 243         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 244             control == LLC_UI) {
 245                 ip_print(gndo, p+4, length-4);
 246                 return (1);
 247         }
 248
 249         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 250             control == LLC_UI) {
 251                 /*
 252                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 253                  * header and an 802.2 LLC header with the source and
 254                  * destination SAPs being the IPX SAP.
 255                  *
 256                  * Skip DSAP, LSAP, and control field.
 257                  */
 258                 if (eflag)
 259                         printf("IPX 802.2: ");
 260
 261                 ipx_print(p+3, length-3);
 262                 return (1);
 263         }
 264
 265 #ifdef TCPDUMP_DO_SMB
 266         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 267             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 268                 /*
 269                  * we don't actually have a full netbeui parser yet, but the
 270                  * smb parser can handle many smb-in-netbeui packets, which
 271                  * is very useful, so we call that
 272                  *
 273                  * We don't call it for S frames, however, just I frames
 274                  * (which are frames that don't have the low-order bit,
 275                  * LLC_S_FMT, set in the first byte of the control field)
 276                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 277                  */
 278
 279                 /*
 280                  * Skip the LLC header.
 281                  */
 282                 if (is_u) {
 283                         p += 3;
 284                         length -= 3;
 285                         caplen -= 3;
 286                 } else {
 287                         p += 4;
 288                         length -= 4;
 289                         caplen -= 4;
 290                 }
 291                 netbeui_print(control, p, length);
 292                 return (1);
 293         }
 294 #endif
 295         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 296             && control == LLC_UI) {
 297                 isoclns_print(p + 3, length - 3, caplen - 3);
 298                 return (1);
 299         }
 300
 301         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 302             && control == LLC_UI) {
 303                 /*
 304                  * XXX - what *is* the right bridge pad value here?
 305                  * Does anybody ever bridge one form of LAN traffic
 306                  * over a networking type that uses 802.2 LLC?
 307                  */
 308                 ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
 309                     2);
 310                 if (ret)
 311                         return (ret);
 312         }
 313
 314         if (!eflag) {
 315                 if (ssap == dsap) {
 316                         if (esrc == NULL || edst == NULL)
 317                                 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 318                         else
 319                                 (void)printf("%s > %s %s ",
 320                                                 etheraddr_string(esrc),
 321                                                 etheraddr_string(edst),
 322                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 323                 } else {
 324                         if (esrc == NULL || edst == NULL)
 325                                 (void)printf("%s > %s ",
 326                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 327                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 328                         else
 329                                 (void)printf("%s %s > %s %s ",
 330                                         etheraddr_string(esrc),
 331                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 332                                         etheraddr_string(edst),
 333                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 334                 }
 335         }
 336
 337         if (is_u) {
 338                 printf("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                 length -= 3;
 345                 caplen -= 3;
 346
 347                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 348                         if (*p == LLC_XID_FI) {
 349                                 printf(": %02x %02x", p[1], p[2]);
 350                                 p += 3;
 351                                 length -= 3;
 352                                 caplen -= 3;
 353                         }
 354                 }
 355         } else {
 356                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 357                         (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 358                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 359                                 LLC_IS_NR(control),
 360                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 361                                 length);
 362                 } else {
 363                         (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 364                                 LLC_I_NS(control),
 365                                 LLC_IS_NR(control),
 366                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 367                                 length);
 368                 }
 369                 p += 4;
 370                 length -= 4;
 371                 caplen -= 4;
 372         }
 373         return(1);
 374 }
 375
 376 int
 377 snap_print(const u_char *p, u_int length, u_int caplen,
 378     u_short *extracted_ethertype, u_int bridge_pad)
 379 {
 380         u_int32_t orgcode;
 381         register u_short et;
 382         register int ret;
 383
 384         TCHECK2(*p, 5);
 385         orgcode = EXTRACT_24BITS(p);
 386         et = EXTRACT_16BITS(p + 3);
 387
 388         if (eflag) {
 389                 const struct tok *tok = null_values;
 390                 const struct oui_tok *otp;
 391
 392                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 393                         if (otp->oui == orgcode) {
 394                                 tok = otp->tok;
 395                                 break;
 396                         }
 397                 }
 398                 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 399                      tok2str(oui_values, "Unknown", orgcode),
 400                      orgcode,
 401                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 402                      tok2str(tok, "Unknown", et),
 403                      et);
 404         }
 405         p += 5;
 406         length -= 5;
 407         caplen -= 5;
 408
 409         switch (orgcode) {
 410         case OUI_ENCAP_ETHER:
 411         case OUI_CISCO_90:
 412                 /*
 413                  * This is an encapsulated Ethernet packet,
 414                  * or a packet bridged by some piece of
 415                  * Cisco hardware; the protocol ID is
 416                  * an Ethernet protocol type.
 417                  */
 418                 ret = ether_encap_print(et, p, length, caplen,
 419                     extracted_ethertype);
 420                 if (ret)
 421                         return (ret);
 422                 break;
 423
 424         case OUI_APPLETALK:
 425                 if (et == ETHERTYPE_ATALK) {
 426                         /*
 427                          * No, I have no idea why Apple used one
 428                          * of their own OUIs, rather than
 429                          * 0x000000, and an Ethernet packet
 430                          * type, for Appletalk data packets,
 431                          * but used 0x000000 and an Ethernet
 432                          * packet type for AARP packets.
 433                          */
 434                         ret = ether_encap_print(et, p, length, caplen,
 435                             extracted_ethertype);
 436                         if (ret)
 437                                 return (ret);
 438                 }
 439                 break;
 440
 441         case OUI_CISCO:
 442                 if (et == PID_CISCO_CDP) {
 443                         cdp_print(p, length, caplen);
 444                         return (1);
 445                 }
 446                 break;
 447
 448         case OUI_RFC2684:
 449                 switch (et) {
 450
 451                 case PID_RFC2684_ETH_FCS:
 452                 case PID_RFC2684_ETH_NOFCS:
 453                         /*
 454                          * XXX - remove the last two bytes for
 455                          * PID_RFC2684_ETH_FCS?
 456                          */
 457                         /*
 458                          * Skip the padding.
 459                          */
 460                         TCHECK2(*p, bridge_pad);
 461                         caplen -= bridge_pad;
 462                         length -= bridge_pad;
 463                         p += bridge_pad;
 464
 465                         /*
 466                          * What remains is an Ethernet packet.
 467                          */
 468                         ether_print(p, length, caplen);
 469                         return (1);
 470
 471                 case PID_RFC2684_802_5_FCS:
 472                 case PID_RFC2684_802_5_NOFCS:
 473                         /*
 474                          * XXX - remove the last two bytes for
 475                          * PID_RFC2684_ETH_FCS?
 476                          */
 477                         /*
 478                          * Skip the padding, but not the Access
 479                          * Control field.
 480                          */
 481                         TCHECK2(*p, bridge_pad);
 482                         caplen -= bridge_pad;
 483                         length -= bridge_pad;
 484                         p += bridge_pad;
 485
 486                         /*
 487                          * What remains is an 802.5 Token Ring
 488                          * packet.
 489                          */
 490                         token_print(p, length, caplen);
 491                         return (1);
 492
 493                 case PID_RFC2684_FDDI_FCS:
 494                 case PID_RFC2684_FDDI_NOFCS:
 495                         /*
 496                          * XXX - remove the last two bytes for
 497                          * PID_RFC2684_ETH_FCS?
 498                          */
 499                         /*
 500                          * Skip the padding.
 501                          */
 502                         TCHECK2(*p, bridge_pad + 1);
 503                         caplen -= bridge_pad + 1;
 504                         length -= bridge_pad + 1;
 505                         p += bridge_pad + 1;
 506
 507                         /*
 508                          * What remains is an FDDI packet.
 509                          */
 510                         fddi_print(p, length, caplen);
 511                         return (1);
 512
 513                 case PID_RFC2684_BPDU:
 514                         stp_print(p, length);
 515                         return (1);
 516                 }
 517         }
 518         return (0);
 519
 520 trunc:
 521         (void)printf("[|snap]");
 522         return (1);
 523 }
 524
 525
 526 /*
 527  * Local Variables:
 528  * c-style: whitesmith
 529  * c-basic-offset: 8
 530  * End:
 531  */