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 1.75 2007-04-13 09:43:11 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         { PID_CISCO_VTP, "VTP" },
 107         { PID_CISCO_DTP, "DTP" },
 108         { PID_CISCO_UDLD, "UDLD" },
 109         { PID_CISCO_PVST, "PVST" },
 110         { 0,             NULL }
 111 };
 112
 113 static const struct tok bridged_values[] = {
 114         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 115         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 116         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 117         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 118         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 119         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 120         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 121         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 122         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 123         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 124         { PID_RFC2684_BPDU,        "BPDU" },
 125         { 0,                       NULL },
 126 };
 127
 128 static const struct tok null_values[] = {
 129         { 0,             NULL }
 130 };
 131
 132 struct oui_tok {
 133         u_int32_t       oui;
 134         const struct tok *tok;
 135 };
 136
 137 static const struct oui_tok oui_to_tok[] = {
 138         { OUI_ENCAP_ETHER, ethertype_values },
 139         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 140         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 141         { OUI_CISCO, cisco_values },
 142         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 143         { 0, NULL }
 144 };
 145
 146 /*
 147  * Returns non-zero IFF it succeeds in printing the header
 148  */
 149 int
 150 llc_print(const u_char *p, u_int length, u_int caplen,
 151           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 152 {
 153         u_int8_t dsap_field, dsap, ssap_field, ssap;
 154         u_int16_t control;
 155         int is_u;
 156         register int ret;
 157
 158         *extracted_ethertype = 0;
 159
 160         if (caplen < 3) {
 161                 (void)printf("[|llc]");
 162                 default_print((u_char *)p, caplen);
 163                 return(0);
 164         }
 165
 166         dsap_field = *p;
 167         ssap_field = *(p + 1);
 168
 169         /*
 170          * OK, what type of LLC frame is this?  The length
 171          * of the control field depends on that - I frames
 172          * have a two-byte control field, and U frames have
 173          * a one-byte control field.
 174          */
 175         control = *(p + 2);
 176         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 177                 /*
 178                  * U frame.
 179                  */
 180                 is_u = 1;
 181         } else {
 182                 /*
 183                  * The control field in I and S frames is
 184                  * 2 bytes...
 185                  */
 186                 if (caplen < 4) {
 187                         (void)printf("[|llc]");
 188                         default_print((u_char *)p, caplen);
 189                         return(0);
 190                 }
 191
 192                 /*
 193                  * ...and is little-endian.
 194                  */
 195                 control = EXTRACT_LE_16BITS(p + 2);
 196                 is_u = 0;
 197         }
 198
 199         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 200                 /*
 201                  * This is an Ethernet_802.3 IPX frame; it has an
 202                  * 802.3 header (i.e., an Ethernet header where the
 203                  * type/length field is <= ETHERMTU, i.e. it's a length
 204                  * field, not a type field), but has no 802.2 header -
 205                  * the IPX packet starts right after the Ethernet header,
 206                  * with a signature of two bytes of 0xFF (which is
 207                  * LLCSAP_GLOBAL).
 208                  *
 209                  * (It might also have been an Ethernet_802.3 IPX at
 210                  * one time, but got bridged onto another network,
 211                  * such as an 802.11 network; this has appeared in at
 212                  * least one capture file.)
 213                  */
 214
 215             if (eflag)
 216                 printf("IPX 802.3: ");
 217
 218             ipx_print(p, length);
 219             return (1);
 220         }
 221
 222         dsap = dsap_field & ~LLC_IG;
 223         ssap = ssap_field & ~LLC_GSAP;
 224
 225         if (eflag) {
 226                 printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 227                        tok2str(llc_values, "Unknown", dsap),
 228                        dsap,
 229                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 230                        tok2str(llc_values, "Unknown", ssap),
 231                        ssap,
 232                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
 233
 234                 if (is_u) {
 235                         printf(", ctrl 0x%02x: ", control);
 236                 } else {
 237                         printf(", ctrl 0x%04x: ", control);
 238                 }
 239         }
 240
 241         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 242             control == LLC_UI) {
 243                 stp_print(p+3, length-3);
 244                 return (1);
 245         }
 246
 247         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 248             control == LLC_UI) {
 249                 ip_print(gndo, p+4, length-4);
 250                 return (1);
 251         }
 252
 253         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 254             control == LLC_UI) {
 255                 /*
 256                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 257                  * header and an 802.2 LLC header with the source and
 258                  * destination SAPs being the IPX SAP.
 259                  *
 260                  * Skip DSAP, LSAP, and control field.
 261                  */
 262                 if (eflag)
 263                         printf("IPX 802.2: ");
 264
 265                 ipx_print(p+3, length-3);
 266                 return (1);
 267         }
 268
 269 #ifdef TCPDUMP_DO_SMB
 270         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 271             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 272                 /*
 273                  * we don't actually have a full netbeui parser yet, but the
 274                  * smb parser can handle many smb-in-netbeui packets, which
 275                  * is very useful, so we call that
 276                  *
 277                  * We don't call it for S frames, however, just I frames
 278                  * (which are frames that don't have the low-order bit,
 279                  * LLC_S_FMT, set in the first byte of the control field)
 280                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 281                  */
 282
 283                 /*
 284                  * Skip the LLC header.
 285                  */
 286                 if (is_u) {
 287                         p += 3;
 288                         length -= 3;
 289                         caplen -= 3;
 290                 } else {
 291                         p += 4;
 292                         length -= 4;
 293                         caplen -= 4;
 294                 }
 295                 netbeui_print(control, p, length);
 296                 return (1);
 297         }
 298 #endif
 299         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 300             && control == LLC_UI) {
 301                 isoclns_print(p + 3, length - 3, caplen - 3);
 302                 return (1);
 303         }
 304
 305         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 306             && control == LLC_UI) {
 307                 /*
 308                  * XXX - what *is* the right bridge pad value here?
 309                  * Does anybody ever bridge one form of LAN traffic
 310                  * over a networking type that uses 802.2 LLC?
 311                  */
 312                 ret = snap_print(p+3, length-3, caplen-3, 2);
 313                 if (ret)
 314                         return (ret);
 315         }
 316
 317         if (!eflag) {
 318                 if (ssap == dsap) {
 319                         if (esrc == NULL || edst == NULL)
 320                                 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 321                         else
 322                                 (void)printf("%s > %s %s ",
 323                                                 etheraddr_string(esrc),
 324                                                 etheraddr_string(edst),
 325                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 326                 } else {
 327                         if (esrc == NULL || edst == NULL)
 328                                 (void)printf("%s > %s ",
 329                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 330                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 331                         else
 332                                 (void)printf("%s %s > %s %s ",
 333                                         etheraddr_string(esrc),
 334                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 335                                         etheraddr_string(edst),
 336                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 337                 }
 338         }
 339
 340         if (is_u) {
 341                 printf("Unnumbered, %s, Flags [%s], length %u",
 342                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 343                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 344                        length);
 345
 346                 p += 3;
 347                 length -= 3;
 348                 caplen -= 3;
 349
 350                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 351                         if (*p == LLC_XID_FI) {
 352                                 printf(": %02x %02x", p[1], p[2]);
 353                                 p += 3;
 354                                 length -= 3;
 355                                 caplen -= 3;
 356                         }
 357                 }
 358         } else {
 359                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 360                         (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 361                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 362                                 LLC_IS_NR(control),
 363                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 364                                 length);
 365                 } else {
 366                         (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 367                                 LLC_I_NS(control),
 368                                 LLC_IS_NR(control),
 369                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 370                                 length);
 371                 }
 372                 p += 4;
 373                 length -= 4;
 374                 caplen -= 4;
 375         }
 376         return(1);
 377 }
 378
 379 int
 380 snap_print(const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
 381 {
 382         u_int32_t orgcode;
 383         register u_short et;
 384         register int ret;
 385
 386         TCHECK2(*p, 5);
 387         orgcode = EXTRACT_24BITS(p);
 388         et = EXTRACT_16BITS(p + 3);
 389
 390         if (eflag) {
 391                 const struct tok *tok = null_values;
 392                 const struct oui_tok *otp;
 393
 394                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 395                         if (otp->oui == orgcode) {
 396                                 tok = otp->tok;
 397                                 break;
 398                         }
 399                 }
 400                 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 401                      tok2str(oui_values, "Unknown", orgcode),
 402                      orgcode,
 403                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 404                      tok2str(tok, "Unknown", et),
 405                      et);
 406         }
 407         p += 5;
 408         length -= 5;
 409         caplen -= 5;
 410
 411         switch (orgcode) {
 412         case OUI_ENCAP_ETHER:
 413         case OUI_CISCO_90:
 414                 /*
 415                  * This is an encapsulated Ethernet packet,
 416                  * or a packet bridged by some piece of
 417                  * Cisco hardware; the protocol ID is
 418                  * an Ethernet protocol type.
 419                  */
 420                 ret = ethertype_print(et, p, length, caplen);
 421                 if (ret)
 422                         return (ret);
 423                 break;
 424
 425         case OUI_APPLETALK:
 426                 if (et == ETHERTYPE_ATALK) {
 427                         /*
 428                          * No, I have no idea why Apple used one
 429                          * of their own OUIs, rather than
 430                          * 0x000000, and an Ethernet packet
 431                          * type, for Appletalk data packets,
 432                          * but used 0x000000 and an Ethernet
 433                          * packet type for AARP packets.
 434                          */
 435                         ret = ethertype_print(et, p, length, caplen);
 436                         if (ret)
 437                                 return (ret);
 438                 }
 439                 break;
 440
 441         case OUI_CISCO:
 442                 switch (et) {
 443                 case PID_CISCO_CDP:
 444                         cdp_print(p, length, caplen);
 445                         return (1);
 446                 case PID_CISCO_DTP:
 447                         dtp_print(p, length);
 448                         return (1);
 449                 case PID_CISCO_UDLD:
 450                         udld_print(p, length);
 451                         return (1);
 452                 case PID_CISCO_VTP:
 453                         vtp_print(p, length);
 454                         return (1);
 455                 case PID_CISCO_PVST:
 456                         stp_print(p, length);
 457                         return (1);
 458                 default:
 459                         break;
 460                 }
 461
 462         case OUI_RFC2684:
 463                 switch (et) {
 464
 465                 case PID_RFC2684_ETH_FCS:
 466                 case PID_RFC2684_ETH_NOFCS:
 467                         /*
 468                          * XXX - remove the last two bytes for
 469                          * PID_RFC2684_ETH_FCS?
 470                          */
 471                         /*
 472                          * Skip the padding.
 473                          */
 474                         TCHECK2(*p, bridge_pad);
 475                         caplen -= bridge_pad;
 476                         length -= bridge_pad;
 477                         p += bridge_pad;
 478
 479                         /*
 480                          * What remains is an Ethernet packet.
 481                          */
 482                         ether_print(p, length, caplen, NULL, NULL);
 483                         return (1);
 484
 485                 case PID_RFC2684_802_5_FCS:
 486                 case PID_RFC2684_802_5_NOFCS:
 487                         /*
 488                          * XXX - remove the last two bytes for
 489                          * PID_RFC2684_ETH_FCS?
 490                          */
 491                         /*
 492                          * Skip the padding, but not the Access
 493                          * Control field.
 494                          */
 495                         TCHECK2(*p, bridge_pad);
 496                         caplen -= bridge_pad;
 497                         length -= bridge_pad;
 498                         p += bridge_pad;
 499
 500                         /*
 501                          * What remains is an 802.5 Token Ring
 502                          * packet.
 503                          */
 504                         token_print(p, length, caplen);
 505                         return (1);
 506
 507                 case PID_RFC2684_FDDI_FCS:
 508                 case PID_RFC2684_FDDI_NOFCS:
 509                         /*
 510                          * XXX - remove the last two bytes for
 511                          * PID_RFC2684_ETH_FCS?
 512                          */
 513                         /*
 514                          * Skip the padding.
 515                          */
 516                         TCHECK2(*p, bridge_pad + 1);
 517                         caplen -= bridge_pad + 1;
 518                         length -= bridge_pad + 1;
 519                         p += bridge_pad + 1;
 520
 521                         /*
 522                          * What remains is an FDDI packet.
 523                          */
 524                         fddi_print(p, length, caplen);
 525                         return (1);
 526
 527                 case PID_RFC2684_BPDU:
 528                         stp_print(p, length);
 529                         return (1);
 530                 }
 531         }
 532         return (0);
 533
 534 trunc:
 535         (void)printf("[|snap]");
 536         return (1);
 537 }
 538
 539
 540 /*
 541  * Local Variables:
 542  * c-style: whitesmith
 543  * c-basic-offset: 8
 544  * End:
 545  */