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 1.66 2005-09-29 07:37:08 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_GSAP|LLC_IS_POLL, "Final" },
  84         { 0, NULL }
  85 };
  86
  87 static const struct tok llc_supervisory_values[] = {
  88         { 0, "Receiver Ready" },
  89         { 1, "Reject" },
  90         { 2, "Receiver not Ready" },
  91         { 0,             NULL }
  92 };
  93
  94
  95 static const struct tok cisco_values[] = {
  96         { PID_CISCO_CDP, "CDP" },
  97         { 0,             NULL }
  98 };
  99
 100 static const struct tok bridged_values[] = {
 101         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 102         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 103         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 104         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 105         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 106         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 107         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 108         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 109         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 110         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 111         { PID_RFC2684_BPDU,        "BPDU" },
 112         { 0,                       NULL },
 113 };
 114
 115 struct oui_tok {
 116         u_int32_t       oui;
 117         const struct tok *tok;
 118 };
 119
 120 static const struct oui_tok oui_to_tok[] = {
 121         { OUI_ENCAP_ETHER, ethertype_values },
 122         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 123         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 124         { OUI_CISCO, cisco_values },
 125         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 126         { 0, NULL }
 127 };
 128
 129 /*
 130  * Returns non-zero IFF it succeeds in printing the header
 131  */
 132 int
 133 llc_print(const u_char *p, u_int length, u_int caplen,
 134           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 135 {
 136         u_int8_t dsap_field, dsap, ssap_field, ssap;
 137         u_int16_t control;
 138         int is_u;
 139         register int ret;
 140
 141         if (caplen < 3) {
 142                 (void)printf("[|llc]");
 143                 default_print((u_char *)p, caplen);
 144                 return(0);
 145         }
 146
 147         dsap_field = *p;
 148         dsap = dsap_field & ~LLC_IG;
 149         ssap_field = *(p + 1);
 150         ssap = ssap_field & ~LLC_GSAP;
 151
 152         /*
 153          * OK, what type of LLC frame is this?  The length
 154          * of the control field depends on that - I frames
 155          * have a two-byte control field, and U frames have
 156          * a one-byte control field.
 157          */
 158         control = *(p + 2);
 159         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 160                 /*
 161                  * U frame.
 162                  */
 163                 is_u = 1;
 164         } else {
 165                 /*
 166                  * The control field in I and S frames is
 167                  * 2 bytes...
 168                  */
 169                 if (caplen < 4) {
 170                         (void)printf("[|llc]");
 171                         default_print((u_char *)p, caplen);
 172                         return(0);
 173                 }
 174
 175                 /*
 176                  * ...and is little-endian.
 177                  */
 178                 control = EXTRACT_LE_16BITS(p + 2);
 179                 is_u = 0;
 180         }
 181
 182         if (ssap == LLCSAP_GLOBAL && dsap == LLCSAP_GLOBAL) {
 183                 /*
 184                  * This is an Ethernet_802.3 IPX frame; it has an
 185                  * 802.3 header (i.e., an Ethernet header where the
 186                  * type/length field is <= ETHERMTU, i.e. it's a length
 187                  * field, not a type field), but has no 802.2 header -
 188                  * the IPX packet starts right after the Ethernet header,
 189                  * with a signature of two bytes of 0xFF (which is
 190                  * LLCSAP_GLOBAL).
 191                  *
 192                  * (It might also have been an Ethernet_802.3 IPX at
 193                  * one time, but got bridged onto another network,
 194                  * such as an 802.11 network; this has appeared in at
 195                  * least one capture file.)
 196                  */
 197
 198             if (eflag)
 199                 printf("IPX 802.3: ");
 200
 201             ipx_print(p, length);
 202             return (1);
 203         }
 204
 205         if (eflag) {
 206                 printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x)",
 207                        tok2str(llc_values, "Unknown", dsap),
 208                        dsap,
 209                        tok2str(llc_values, "Unknown", ssap),
 210                        ssap);
 211
 212                 if (is_u) {
 213                         printf(", cmd 0x%02x: ", control);
 214                 } else {
 215                         printf(", cmd 0x%04x: ", control);
 216                 }
 217         }
 218
 219         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 220             control == LLC_UI) {
 221                 stp_print(p+3, length-3);
 222                 return (1);
 223         }
 224
 225         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 226             control == LLC_UI) {
 227                 ip_print(gndo, p+4, length-4);
 228                 return (1);
 229         }
 230
 231         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 232             control == LLC_UI) {
 233                 /*
 234                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 235                  * header and an 802.2 LLC header with the source and
 236                  * destination SAPs being the IPX SAP.
 237                  *
 238                  * Skip DSAP, LSAP, and control field.
 239                  */
 240                 if (eflag)
 241                         printf("IPX 802.2: ");
 242
 243                 ipx_print(p+3, length-3);
 244                 return (1);
 245         }
 246
 247 #ifdef TCPDUMP_DO_SMB
 248         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 249             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 250                 /*
 251                  * we don't actually have a full netbeui parser yet, but the
 252                  * smb parser can handle many smb-in-netbeui packets, which
 253                  * is very useful, so we call that
 254                  *
 255                  * We don't call it for S frames, however, just I frames
 256                  * (which are frames that don't have the low-order bit,
 257                  * LLC_S_FMT, set in the first byte of the control field)
 258                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 259                  */
 260
 261                 /*
 262                  * Skip the LLC header.
 263                  */
 264                 if (is_u) {
 265                         p += 3;
 266                         length -= 3;
 267                         caplen -= 3;
 268                 } else {
 269                         p += 4;
 270                         length -= 4;
 271                         caplen -= 4;
 272                 }
 273                 netbeui_print(control, p, length);
 274                 return (1);
 275         }
 276 #endif
 277         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 278             && control == LLC_UI) {
 279                 isoclns_print(p + 3, length - 3, caplen - 3);
 280                 return (1);
 281         }
 282
 283         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 284             && control == LLC_UI) {
 285                 /*
 286                  * XXX - what *is* the right bridge pad value here?
 287                  * Does anybody ever bridge one form of LAN traffic
 288                  * over a networking type that uses 802.2 LLC?
 289                  */
 290                 ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
 291                     2);
 292                 if (ret)
 293                         return (ret);
 294         }
 295
 296         if (!eflag) {
 297                 if (ssap == dsap) {
 298                         if (esrc == NULL || edst == NULL)
 299                                 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 300                         else
 301                                 (void)printf("%s > %s %s ",
 302                                                 etheraddr_string(esrc),
 303                                                 etheraddr_string(edst),
 304                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 305                 } else {
 306                         if (esrc == NULL || edst == NULL)
 307                                 (void)printf("%s > %s ",
 308                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 309                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 310                         else
 311                                 (void)printf("%s %s > %s %s ",
 312                                         etheraddr_string(esrc),
 313                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 314                                         etheraddr_string(edst),
 315                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 316                 }
 317         }
 318
 319         if (is_u) {
 320                 printf("Unnumbered, %s, Flags [%s], length %u",
 321                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 322                        bittok2str(llc_flag_values,"?",(ssap) | (control & LLC_U_POLL)),
 323                        length);
 324
 325                 p += 3;
 326                 length -= 3;
 327                 caplen -= 3;
 328
 329                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 330                         if (*p == LLC_XID_FI) {
 331                                 printf(": %02x %02x", p[1], p[2]);
 332                                 p += 3;
 333                                 length -= 3;
 334                                 caplen -= 3;
 335                         }
 336                 }
 337         } else {
 338
 339                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 340                         (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 341                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 342                                 LLC_IS_NR(control),
 343                                 bittok2str(llc_flag_values,"?",(ssap) | (control & LLC_IS_POLL)),
 344                                 length);
 345                 } else {
 346                         (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 347                                 LLC_I_NS(control),
 348                                 LLC_IS_NR(control),
 349                                 bittok2str(llc_flag_values,"?",(ssap) | (control & LLC_IS_POLL)),
 350                                 length);
 351                 }
 352                 p += 4;
 353                 length -= 4;
 354                 caplen -= 4;
 355         }
 356         return(1);
 357 }
 358
 359 int
 360 snap_print(const u_char *p, u_int length, u_int caplen,
 361     u_short *extracted_ethertype, u_int bridge_pad)
 362 {
 363         u_int32_t orgcode;
 364         register u_short et;
 365         register int ret;
 366
 367         TCHECK2(*p, 5);
 368         orgcode = EXTRACT_24BITS(p);
 369         et = EXTRACT_16BITS(p + 3);
 370
 371         if (eflag) {
 372                 const struct tok *tok = NULL;
 373                 const struct oui_tok *otp;
 374
 375                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 376                         if (otp->oui == orgcode) {
 377                                 tok = otp->tok;
 378                                 break;
 379                         }
 380                 }
 381                 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 382                      tok2str(oui_values, "Unknown", orgcode),
 383                      orgcode,
 384                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 385                      tok2str(tok, "Unknown", et),
 386                      et);
 387         }
 388         p += 5;
 389         length -= 5;
 390         caplen -= 5;
 391
 392         switch (orgcode) {
 393         case OUI_ENCAP_ETHER:
 394         case OUI_CISCO_90:
 395                 /*
 396                  * This is an encapsulated Ethernet packet,
 397                  * or a packet bridged by some piece of
 398                  * Cisco hardware; the protocol ID is
 399                  * an Ethernet protocol type.
 400                  */
 401                 ret = ether_encap_print(et, p, length, caplen,
 402                     extracted_ethertype);
 403                 if (ret)
 404                         return (ret);
 405                 break;
 406
 407         case OUI_APPLETALK:
 408                 if (et == ETHERTYPE_ATALK) {
 409                         /*
 410                          * No, I have no idea why Apple used one
 411                          * of their own OUIs, rather than
 412                          * 0x000000, and an Ethernet packet
 413                          * type, for Appletalk data packets,
 414                          * but used 0x000000 and an Ethernet
 415                          * packet type for AARP packets.
 416                          */
 417                         ret = ether_encap_print(et, p, length, caplen,
 418                             extracted_ethertype);
 419                         if (ret)
 420                                 return (ret);
 421                 }
 422                 break;
 423
 424         case OUI_CISCO:
 425                 if (et == PID_CISCO_CDP) {
 426                         cdp_print(p, length, caplen);
 427                         return (1);
 428                 }
 429                 break;
 430
 431         case OUI_RFC2684:
 432                 switch (et) {
 433
 434                 case PID_RFC2684_ETH_FCS:
 435                 case PID_RFC2684_ETH_NOFCS:
 436                         /*
 437                          * XXX - remove the last two bytes for
 438                          * PID_RFC2684_ETH_FCS?
 439                          */
 440                         /*
 441                          * Skip the padding.
 442                          */
 443                         TCHECK2(*p, bridge_pad);
 444                         caplen -= bridge_pad;
 445                         length -= bridge_pad;
 446                         p += bridge_pad;
 447
 448                         /*
 449                          * What remains is an Ethernet packet.
 450                          */
 451                         ether_print(p, length, caplen);
 452                         return (1);
 453
 454                 case PID_RFC2684_802_5_FCS:
 455                 case PID_RFC2684_802_5_NOFCS:
 456                         /*
 457                          * XXX - remove the last two bytes for
 458                          * PID_RFC2684_ETH_FCS?
 459                          */
 460                         /*
 461                          * Skip the padding, but not the Access
 462                          * Control field.
 463                          */
 464                         TCHECK2(*p, bridge_pad);
 465                         caplen -= bridge_pad;
 466                         length -= bridge_pad;
 467                         p += bridge_pad;
 468
 469                         /*
 470                          * What remains is an 802.5 Token Ring
 471                          * packet.
 472                          */
 473                         token_print(p, length, caplen);
 474                         return (1);
 475
 476                 case PID_RFC2684_FDDI_FCS:
 477                 case PID_RFC2684_FDDI_NOFCS:
 478                         /*
 479                          * XXX - remove the last two bytes for
 480                          * PID_RFC2684_ETH_FCS?
 481                          */
 482                         /*
 483                          * Skip the padding.
 484                          */
 485                         TCHECK2(*p, bridge_pad + 1);
 486                         caplen -= bridge_pad + 1;
 487                         length -= bridge_pad + 1;
 488                         p += bridge_pad + 1;
 489
 490                         /*
 491                          * What remains is an FDDI packet.
 492                          */
 493                         fddi_print(p, length, caplen);
 494                         return (1);
 495
 496                 case PID_RFC2684_BPDU:
 497                         stp_print(p, length);
 498                         return (1);
 499                 }
 500         }
 501         return (0);
 502
 503 trunc:
 504         (void)printf("[|snap]");
 505         return (1);
 506 }
 507
 508
 509 /*
 510  * Local Variables:
 511  * c-style: whitesmith
 512  * c-basic-offset: 8
 513  * End:
 514  */