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 #define NETDISSECT_REWORKED
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <tcpdump-stdinc.h>
  31
  32 #include "interface.h"
  33 #include "addrtoname.h"
  34 #include "extract.h"                    /* must come after interface.h */
  35
  36 #include "llc.h"
  37 #include "ethertype.h"
  38 #include "oui.h"
  39
  40 static const struct tok llc_values[] = {
  41         { LLCSAP_NULL,     "Null" },
  42         { LLCSAP_GLOBAL,   "Global" },
  43         { LLCSAP_8021B_I,  "802.1B I" },
  44         { LLCSAP_8021B_G,  "802.1B G" },
  45         { LLCSAP_IP,       "IP" },
  46         { LLCSAP_SNA,      "SNA" },
  47         { LLCSAP_PROWAYNM, "ProWay NM" },
  48         { LLCSAP_8021D,    "STP" },
  49         { LLCSAP_RS511,    "RS511" },
  50         { LLCSAP_ISO8208,  "ISO8208" },
  51         { LLCSAP_PROWAY,   "ProWay" },
  52         { LLCSAP_SNAP,     "SNAP" },
  53         { LLCSAP_IPX,      "IPX" },
  54         { LLCSAP_NETBEUI,  "NetBeui" },
  55         { LLCSAP_ISONS,    "OSI" },
  56         { 0,               NULL },
  57 };
  58
  59 static const struct tok llc_cmd_values[] = {
  60         { LLC_UI,       "ui" },
  61         { LLC_TEST,     "test" },
  62         { LLC_XID,      "xid" },
  63         { LLC_UA,       "ua" },
  64         { LLC_DISC,     "disc" },
  65         { LLC_DM,       "dm" },
  66         { LLC_SABME,    "sabme" },
  67         { LLC_FRMR,     "frmr" },
  68         { 0,            NULL }
  69 };
  70
  71 static const struct tok llc_flag_values[] = {
  72         { 0, "Command" },
  73         { LLC_GSAP, "Response" },
  74         { LLC_U_POLL, "Poll" },
  75         { LLC_GSAP|LLC_U_POLL, "Final" },
  76         { LLC_IS_POLL, "Poll" },
  77         { LLC_GSAP|LLC_IS_POLL, "Final" },
  78         { 0, NULL }
  79 };
  80
  81
  82 static const struct tok llc_ig_flag_values[] = {
  83         { 0, "Individual" },
  84         { LLC_IG, "Group" },
  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         { PID_CISCO_VTP, "VTP" },
 100         { PID_CISCO_DTP, "DTP" },
 101         { PID_CISCO_UDLD, "UDLD" },
 102         { PID_CISCO_PVST, "PVST" },
 103         { PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
 104         { 0,             NULL }
 105 };
 106
 107 static const struct tok bridged_values[] = {
 108         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 109         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 110         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 111         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 112         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 113         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 114         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 115         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 116         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 117         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 118         { PID_RFC2684_BPDU,        "BPDU" },
 119         { 0,                       NULL },
 120 };
 121
 122 static const struct tok null_values[] = {
 123         { 0,             NULL }
 124 };
 125
 126 struct oui_tok {
 127         uint32_t        oui;
 128         const struct tok *tok;
 129 };
 130
 131 static const struct oui_tok oui_to_tok[] = {
 132         { OUI_ENCAP_ETHER, ethertype_values },
 133         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 134         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 135         { OUI_CISCO, cisco_values },
 136         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 137         { 0, NULL }
 138 };
 139
 140 /*
 141  * Returns non-zero IFF it succeeds in printing the header
 142  */
 143 int
 144 llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 145           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 146 {
 147         uint8_t dsap_field, dsap, ssap_field, ssap;
 148         uint16_t control;
 149         int is_u;
 150         register int ret;
 151
 152         *extracted_ethertype = 0;
 153
 154         if (caplen < 3) {
 155                 ND_PRINT((ndo, "[|llc]"));
 156                 ND_DEFAULTPRINT((u_char *)p, caplen);
 157                 return(0);
 158         }
 159
 160         dsap_field = *p;
 161         ssap_field = *(p + 1);
 162
 163         /*
 164          * OK, what type of LLC frame is this?  The length
 165          * of the control field depends on that - I frames
 166          * have a two-byte control field, and U frames have
 167          * a one-byte control field.
 168          */
 169         control = *(p + 2);
 170         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 171                 /*
 172                  * U frame.
 173                  */
 174                 is_u = 1;
 175         } else {
 176                 /*
 177                  * The control field in I and S frames is
 178                  * 2 bytes...
 179                  */
 180                 if (caplen < 4) {
 181                         ND_PRINT((ndo, "[|llc]"));
 182                         ND_DEFAULTPRINT((u_char *)p, caplen);
 183                         return(0);
 184                 }
 185
 186                 /*
 187                  * ...and is little-endian.
 188                  */
 189                 control = EXTRACT_LE_16BITS(p + 2);
 190                 is_u = 0;
 191         }
 192
 193         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 194                 /*
 195                  * This is an Ethernet_802.3 IPX frame; it has an
 196                  * 802.3 header (i.e., an Ethernet header where the
 197                  * type/length field is <= ETHERMTU, i.e. it's a length
 198                  * field, not a type field), but has no 802.2 header -
 199                  * the IPX packet starts right after the Ethernet header,
 200                  * with a signature of two bytes of 0xFF (which is
 201                  * LLCSAP_GLOBAL).
 202                  *
 203                  * (It might also have been an Ethernet_802.3 IPX at
 204                  * one time, but got bridged onto another network,
 205                  * such as an 802.11 network; this has appeared in at
 206                  * least one capture file.)
 207                  */
 208
 209             if (ndo->ndo_eflag)
 210                 ND_PRINT((ndo, "IPX 802.3: "));
 211
 212             ipx_print(ndo, p, length);
 213             return (1);
 214         }
 215
 216         dsap = dsap_field & ~LLC_IG;
 217         ssap = ssap_field & ~LLC_GSAP;
 218
 219         if (ndo->ndo_eflag) {
 220                 ND_PRINT((ndo, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 221                        tok2str(llc_values, "Unknown", dsap),
 222                        dsap,
 223                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 224                        tok2str(llc_values, "Unknown", ssap),
 225                        ssap,
 226                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP)));
 227
 228                 if (is_u) {
 229                         ND_PRINT((ndo, ", ctrl 0x%02x: ", control));
 230                 } else {
 231                         ND_PRINT((ndo, ", ctrl 0x%04x: ", control));
 232                 }
 233         }
 234
 235         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 236             control == LLC_UI) {
 237                 stp_print(ndo, p+3, length-3);
 238                 return (1);
 239         }
 240
 241         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 242             control == LLC_UI) {
 243                 ip_print(ndo, p+4, length-4);
 244                 return (1);
 245         }
 246
 247         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 248             control == LLC_UI) {
 249                 /*
 250                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 251                  * header and an 802.2 LLC header with the source and
 252                  * destination SAPs being the IPX SAP.
 253                  *
 254                  * Skip DSAP, LSAP, and control field.
 255                  */
 256                 if (ndo->ndo_eflag)
 257                         ND_PRINT((ndo, "IPX 802.2: "));
 258
 259                 ipx_print(ndo, p+3, length-3);
 260                 return (1);
 261         }
 262
 263 #ifdef TCPDUMP_DO_SMB
 264         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 265             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 266                 /*
 267                  * we don't actually have a full netbeui parser yet, but the
 268                  * smb parser can handle many smb-in-netbeui packets, which
 269                  * is very useful, so we call that
 270                  *
 271                  * We don't call it for S frames, however, just I frames
 272                  * (which are frames that don't have the low-order bit,
 273                  * LLC_S_FMT, set in the first byte of the control field)
 274                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 275                  */
 276
 277                 /*
 278                  * Skip the LLC header.
 279                  */
 280                 if (is_u) {
 281                         p += 3;
 282                         length -= 3;
 283                 } else {
 284                         p += 4;
 285                         length -= 4;
 286                 }
 287                 netbeui_print(ndo, control, p, length);
 288                 return (1);
 289         }
 290 #endif
 291         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 292             && control == LLC_UI) {
 293                 isoclns_print(ndo, 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(ndo, p+3, length-3, caplen-3, 2);
 305                 if (ret)
 306                         return (ret);
 307         }
 308
 309         if (!ndo->ndo_eflag) {
 310                 if (ssap == dsap) {
 311                         if (esrc == NULL || edst == NULL)
 312                                 ND_PRINT((ndo, "%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 313                         else
 314                                 ND_PRINT((ndo, "%s > %s %s ",
 315                                                 etheraddr_string(ndo, esrc),
 316                                                 etheraddr_string(ndo, edst),
 317                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 318                 } else {
 319                         if (esrc == NULL || edst == NULL)
 320                                 ND_PRINT((ndo, "%s > %s ",
 321                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 322                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 323                         else
 324                                 ND_PRINT((ndo, "%s %s > %s %s ",
 325                                         etheraddr_string(ndo, esrc),
 326                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 327                                         etheraddr_string(ndo, edst),
 328                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 329                 }
 330         }
 331
 332         if (is_u) {
 333                 ND_PRINT((ndo, "Unnumbered, %s, Flags [%s], length %u",
 334                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 335                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 336                        length));
 337
 338                 p += 3;
 339
 340                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 341                         if (*p == LLC_XID_FI) {
 342                                 ND_PRINT((ndo, ": %02x %02x", p[1], p[2]));
 343                         }
 344                 }
 345         } else {
 346                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 347                         ND_PRINT((ndo, "Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 348                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 349                                 LLC_IS_NR(control),
 350                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 351                                 length));
 352                 } else {
 353                         ND_PRINT((ndo, "Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 354                                 LLC_I_NS(control),
 355                                 LLC_IS_NR(control),
 356                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 357                                 length));
 358                 }
 359         }
 360         return(1);
 361 }
 362
 363 int
 364 snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
 365 {
 366         uint32_t orgcode;
 367         register u_short et;
 368         register int ret;
 369
 370         ND_TCHECK2(*p, 5);
 371         orgcode = EXTRACT_24BITS(p);
 372         et = EXTRACT_16BITS(p + 3);
 373
 374         if (ndo->ndo_eflag) {
 375                 const struct tok *tok = null_values;
 376                 const struct oui_tok *otp;
 377
 378                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 379                         if (otp->oui == orgcode) {
 380                                 tok = otp->tok;
 381                                 break;
 382                         }
 383                 }
 384                 ND_PRINT((ndo, "oui %s (0x%06x), %s %s (0x%04x): ",
 385                      tok2str(oui_values, "Unknown", orgcode),
 386                      orgcode,
 387                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 388                      tok2str(tok, "Unknown", et),
 389                      et));
 390         }
 391         p += 5;
 392         length -= 5;
 393         caplen -= 5;
 394
 395         switch (orgcode) {
 396         case OUI_ENCAP_ETHER:
 397         case OUI_CISCO_90:
 398                 /*
 399                  * This is an encapsulated Ethernet packet,
 400                  * or a packet bridged by some piece of
 401                  * Cisco hardware; the protocol ID is
 402                  * an Ethernet protocol type.
 403                  */
 404                 ret = ethertype_print(ndo, et, p, length, caplen);
 405                 if (ret)
 406                         return (ret);
 407                 break;
 408
 409         case OUI_APPLETALK:
 410                 if (et == ETHERTYPE_ATALK) {
 411                         /*
 412                          * No, I have no idea why Apple used one
 413                          * of their own OUIs, rather than
 414                          * 0x000000, and an Ethernet packet
 415                          * type, for Appletalk data packets,
 416                          * but used 0x000000 and an Ethernet
 417                          * packet type for AARP packets.
 418                          */
 419                         ret = ethertype_print(ndo, et, p, length, caplen);
 420                         if (ret)
 421                                 return (ret);
 422                 }
 423                 break;
 424
 425         case OUI_CISCO:
 426                 switch (et) {
 427                 case PID_CISCO_CDP:
 428                         cdp_print(ndo, p, length, caplen);
 429                         return (1);
 430                 case PID_CISCO_DTP:
 431                         dtp_print(ndo, p, length);
 432                         return (1);
 433                 case PID_CISCO_UDLD:
 434                         udld_print(ndo, p, length);
 435                         return (1);
 436                 case PID_CISCO_VTP:
 437                         vtp_print(ndo, p, length);
 438                         return (1);
 439                 case PID_CISCO_PVST:
 440                 case PID_CISCO_VLANBRIDGE:
 441                         stp_print(ndo, p, length);
 442                         return (1);
 443                 default:
 444                         break;
 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                         ND_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(ndo, p, length, caplen, NULL, NULL);
 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                         ND_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(ndo, 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                         ND_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(ndo, p, length, caplen);
 511                         return (1);
 512
 513                 case PID_RFC2684_BPDU:
 514                         stp_print(ndo, p, length);
 515                         return (1);
 516                 }
 517         }
 518         return (0);
 519
 520 trunc:
 521         ND_PRINT((ndo, "[|snap]"));
 522         return (1);
 523 }
 524
 525
 526 /*
 527  * Local Variables:
 528  * c-style: whitesmith
 529  * c-basic-offset: 8
 530  * End:
 531  */