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 1.65 2005-04-26 07:26:34 guy 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_PROWAYNM, "ProWay NM" },
  54         { LLCSAP_8021D,    "STP" },
  55         { LLCSAP_RS511,    "RS511" },
  56         { LLCSAP_ISO8208,  "ISO8208" },
  57         { LLCSAP_PROWAY,   "ProWay" },
  58         { LLCSAP_SNAP,     "SNAP" },
  59         { LLCSAP_IPX,      "IPX" },
  60         { LLCSAP_NETBEUI,  "NetBeui" },
  61         { LLCSAP_ISONS,    "OSI" },
  62         { 0,               NULL },
  63 };
  64
  65 static struct tok cmd2str[] = {
  66         { LLC_UI,       "ui" },
  67         { LLC_TEST,     "test" },
  68         { LLC_XID,      "xid" },
  69         { LLC_UA,       "ua" },
  70         { LLC_DISC,     "disc" },
  71         { LLC_DM,       "dm" },
  72         { LLC_SABME,    "sabme" },
  73         { LLC_FRMR,     "frmr" },
  74         { 0,            NULL }
  75 };
  76
  77 static const struct tok cisco_values[] = {
  78         { PID_CISCO_CDP, "CDP" },
  79         { 0,             NULL }
  80 };
  81
  82 static const struct tok bridged_values[] = {
  83         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
  84         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
  85         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
  86         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
  87         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
  88         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
  89         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
  90         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
  91         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
  92         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
  93         { PID_RFC2684_BPDU,        "BPDU" },
  94         { 0,                       NULL },
  95 };
  96
  97 struct oui_tok {
  98         u_int32_t       oui;
  99         const struct tok *tok;
 100 };
 101
 102 static const struct oui_tok oui_to_tok[] = {
 103         { OUI_ENCAP_ETHER, ethertype_values },
 104         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 105         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 106         { OUI_CISCO, cisco_values },
 107         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 108         { 0, NULL }
 109 };
 110
 111 /*
 112  * Returns non-zero IFF it succeeds in printing the header
 113  */
 114 int
 115 llc_print(const u_char *p, u_int length, u_int caplen,
 116           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 117 {
 118         u_int8_t dsap, ssap;
 119         u_int16_t control;
 120         int is_u;
 121         register int ret;
 122
 123         if (caplen < 3) {
 124                 (void)printf("[|llc]");
 125                 default_print((u_char *)p, caplen);
 126                 return(0);
 127         }
 128
 129         dsap = *p;
 130         ssap = *(p + 1);
 131
 132         /*
 133          * OK, what type of LLC frame is this?  The length
 134          * of the control field depends on that - I frames
 135          * have a two-byte control field, and U frames have
 136          * a one-byte control field.
 137          */
 138         control = *(p + 2);
 139         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 140                 /*
 141                  * U frame.
 142                  */
 143                 is_u = 1;
 144         } else {
 145                 /*
 146                  * The control field in I and S frames is
 147                  * 2 bytes...
 148                  */
 149                 if (caplen < 4) {
 150                         (void)printf("[|llc]");
 151                         default_print((u_char *)p, caplen);
 152                         return(0);
 153                 }
 154
 155                 /*
 156                  * ...and is little-endian.
 157                  */
 158                 control = EXTRACT_LE_16BITS(p + 2);
 159                 is_u = 0;
 160         }
 161
 162         if (ssap == LLCSAP_GLOBAL && dsap == LLCSAP_GLOBAL) {
 163                 /*
 164                  * This is an Ethernet_802.3 IPX frame; it has an
 165                  * 802.3 header (i.e., an Ethernet header where the
 166                  * type/length field is <= ETHERMTU, i.e. it's a length
 167                  * field, not a type field), but has no 802.2 header -
 168                  * the IPX packet starts right after the Ethernet header,
 169                  * with a signature of two bytes of 0xFF (which is
 170                  * LLCSAP_GLOBAL).
 171                  *
 172                  * (It might also have been an Ethernet_802.3 IPX at
 173                  * one time, but got bridged onto another network,
 174                  * such as an 802.11 network; this has appeared in at
 175                  * least one capture file.)
 176                  */
 177
 178             if (eflag)
 179                 printf("IPX-802.3: ");
 180
 181             ipx_print(p, length);
 182             return (1);
 183         }
 184
 185         if (eflag) {
 186                 if (is_u) {
 187                         printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x: ",
 188                             tok2str(llc_values, "Unknown", dsap),
 189                             dsap,
 190                             tok2str(llc_values, "Unknown", ssap),
 191                             ssap,
 192                             control);
 193                 } else {
 194                         printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%04x: ",
 195                             tok2str(llc_values, "Unknown", dsap),
 196                             dsap,
 197                             tok2str(llc_values, "Unknown", ssap),
 198                             ssap,
 199                             control);
 200                 }
 201         }
 202
 203         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 204             control == LLC_UI) {
 205                 stp_print(p+3, length-3);
 206                 return (1);
 207         }
 208
 209         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 210             control == LLC_UI) {
 211                 ip_print(gndo, p+4, length-4);
 212                 return (1);
 213         }
 214
 215         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 216             control == LLC_UI) {
 217                 /*
 218                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 219                  * header and an 802.2 LLC header with the source and
 220                  * destination SAPs being the IPX SAP.
 221                  *
 222                  * Skip DSAP, LSAP, and control field.
 223                  */
 224                 printf("(NOV-802.2) ");
 225                 ipx_print(p+3, length-3);
 226                 return (1);
 227         }
 228
 229 #ifdef TCPDUMP_DO_SMB
 230         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 231             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 232                 /*
 233                  * we don't actually have a full netbeui parser yet, but the
 234                  * smb parser can handle many smb-in-netbeui packets, which
 235                  * is very useful, so we call that
 236                  *
 237                  * We don't call it for S frames, however, just I frames
 238                  * (which are frames that don't have the low-order bit,
 239                  * LLC_S_FMT, set in the first byte of the control field)
 240                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 241                  */
 242
 243                 /*
 244                  * Skip the LLC header.
 245                  */
 246                 if (is_u) {
 247                         p += 3;
 248                         length -= 3;
 249                         caplen -= 3;
 250                 } else {
 251                         p += 4;
 252                         length -= 4;
 253                         caplen -= 4;
 254                 }
 255                 netbeui_print(control, p, length);
 256                 return (1);
 257         }
 258 #endif
 259         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 260             && control == LLC_UI) {
 261                 isoclns_print(p + 3, length - 3, caplen - 3);
 262                 return (1);
 263         }
 264
 265         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 266             && control == LLC_UI) {
 267                 /*
 268                  * XXX - what *is* the right bridge pad value here?
 269                  * Does anybody ever bridge one form of LAN traffic
 270                  * over a networking type that uses 802.2 LLC?
 271                  */
 272                 ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
 273                     2);
 274                 if (ret)
 275                         return (ret);
 276         }
 277
 278         if (!eflag) {
 279                 if ((ssap & ~LLC_GSAP) == dsap) {
 280                         if (esrc == NULL || edst == NULL)
 281                                 (void)printf("%s ", llcsap_string(dsap));
 282                         else
 283                                 (void)printf("%s > %s %s ",
 284                                                 etheraddr_string(esrc),
 285                                                 etheraddr_string(edst),
 286                                                 llcsap_string(dsap));
 287                 } else {
 288                         if (esrc == NULL || edst == NULL)
 289                                 (void)printf("%s > %s ",
 290                                         llcsap_string(ssap & ~LLC_GSAP),
 291                                         llcsap_string(dsap));
 292                         else
 293                                 (void)printf("%s %s > %s %s ",
 294                                         etheraddr_string(esrc),
 295                                         llcsap_string(ssap & ~LLC_GSAP),
 296                                         etheraddr_string(edst),
 297                                         llcsap_string(dsap));
 298                 }
 299         }
 300
 301         if (is_u) {
 302                 const char *m;
 303                 char f;
 304
 305                 m = tok2str(cmd2str, "%02x", LLC_U_CMD(control));
 306                 switch ((ssap & LLC_GSAP) | (control & LLC_U_POLL)) {
 307                         case 0:                 f = 'C'; break;
 308                         case LLC_GSAP:          f = 'R'; break;
 309                         case LLC_U_POLL:        f = 'P'; break;
 310                         case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
 311                         default:                f = '?'; break;
 312                 }
 313
 314                 printf("%s/%c", m, f);
 315
 316                 p += 3;
 317                 length -= 3;
 318                 caplen -= 3;
 319
 320                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 321                         if (*p == LLC_XID_FI) {
 322                                 printf(": %02x %02x", p[1], p[2]);
 323                                 p += 3;
 324                                 length -= 3;
 325                                 caplen -= 3;
 326                         }
 327                 }
 328         } else {
 329                 char f;
 330
 331                 switch ((ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
 332                         case 0:                 f = 'C'; break;
 333                         case LLC_GSAP:          f = 'R'; break;
 334                         case LLC_IS_POLL:       f = 'P'; break;
 335                         case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
 336                         default:                f = '?'; break;
 337                 }
 338
 339                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 340                         static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
 341                         (void)printf("%s (r=%d,%c)",
 342                                 llc_s[LLC_S_CMD(control)],
 343                                 LLC_IS_NR(control),
 344                                 f);
 345                 } else {
 346                         (void)printf("I (s=%d,r=%d,%c)",
 347                                 LLC_I_NS(control),
 348                                 LLC_IS_NR(control),
 349                                 f);
 350                 }
 351                 p += 4;
 352                 length -= 4;
 353                 caplen -= 4;
 354         }
 355         return(1);
 356 }
 357
 358 int
 359 snap_print(const u_char *p, u_int length, u_int caplen,
 360     u_short *extracted_ethertype, u_int bridge_pad)
 361 {
 362         u_int32_t orgcode;
 363         register u_short et;
 364         register int ret;
 365
 366         TCHECK2(*p, 5);
 367         orgcode = EXTRACT_24BITS(p);
 368         et = EXTRACT_16BITS(p + 3);
 369
 370         if (eflag) {
 371                 const struct tok *tok = NULL;
 372                 const struct oui_tok *otp;
 373
 374                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 375                         if (otp->oui == orgcode) {
 376                                 tok = otp->tok;
 377                                 break;
 378                         }
 379                 }
 380                 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 381                      tok2str(oui_values, "Unknown", orgcode),
 382                      orgcode,
 383                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 384                      tok2str(tok, "Unknown", et),
 385                      et);
 386         }
 387         p += 5;
 388         length -= 5;
 389         caplen -= 5;
 390
 391         switch (orgcode) {
 392         case OUI_ENCAP_ETHER:
 393         case OUI_CISCO_90:
 394                 /*
 395                  * This is an encapsulated Ethernet packet,
 396                  * or a packet bridged by some piece of
 397                  * Cisco hardware; the protocol ID is
 398                  * an Ethernet protocol type.
 399                  */
 400                 ret = ether_encap_print(et, p, length, caplen,
 401                     extracted_ethertype);
 402                 if (ret)
 403                         return (ret);
 404                 break;
 405
 406         case OUI_APPLETALK:
 407                 if (et == ETHERTYPE_ATALK) {
 408                         /*
 409                          * No, I have no idea why Apple used one
 410                          * of their own OUIs, rather than
 411                          * 0x000000, and an Ethernet packet
 412                          * type, for Appletalk data packets,
 413                          * but used 0x000000 and an Ethernet
 414                          * packet type for AARP packets.
 415                          */
 416                         ret = ether_encap_print(et, p, length, caplen,
 417                             extracted_ethertype);
 418                         if (ret)
 419                                 return (ret);
 420                 }
 421                 break;
 422
 423         case OUI_CISCO:
 424                 if (et == PID_CISCO_CDP) {
 425                         cdp_print(p, length, caplen);
 426                         return (1);
 427                 }
 428                 break;
 429
 430         case OUI_RFC2684:
 431                 switch (et) {
 432
 433                 case PID_RFC2684_ETH_FCS:
 434                 case PID_RFC2684_ETH_NOFCS:
 435                         /*
 436                          * XXX - remove the last two bytes for
 437                          * PID_RFC2684_ETH_FCS?
 438                          */
 439                         /*
 440                          * Skip the padding.
 441                          */
 442                         TCHECK2(*p, bridge_pad);
 443                         caplen -= bridge_pad;
 444                         length -= bridge_pad;
 445                         p += bridge_pad;
 446
 447                         /*
 448                          * What remains is an Ethernet packet.
 449                          */
 450                         ether_print(p, length, caplen);
 451                         return (1);
 452
 453                 case PID_RFC2684_802_5_FCS:
 454                 case PID_RFC2684_802_5_NOFCS:
 455                         /*
 456                          * XXX - remove the last two bytes for
 457                          * PID_RFC2684_ETH_FCS?
 458                          */
 459                         /*
 460                          * Skip the padding, but not the Access
 461                          * Control field.
 462                          */
 463                         TCHECK2(*p, bridge_pad);
 464                         caplen -= bridge_pad;
 465                         length -= bridge_pad;
 466                         p += bridge_pad;
 467
 468                         /*
 469                          * What remains is an 802.5 Token Ring
 470                          * packet.
 471                          */
 472                         token_print(p, length, caplen);
 473                         return (1);
 474
 475                 case PID_RFC2684_FDDI_FCS:
 476                 case PID_RFC2684_FDDI_NOFCS:
 477                         /*
 478                          * XXX - remove the last two bytes for
 479                          * PID_RFC2684_ETH_FCS?
 480                          */
 481                         /*
 482                          * Skip the padding.
 483                          */
 484                         TCHECK2(*p, bridge_pad + 1);
 485                         caplen -= bridge_pad + 1;
 486                         length -= bridge_pad + 1;
 487                         p += bridge_pad + 1;
 488
 489                         /*
 490                          * What remains is an FDDI packet.
 491                          */
 492                         fddi_print(p, length, caplen);
 493                         return (1);
 494
 495                 case PID_RFC2684_BPDU:
 496                         stp_print(p, length);
 497                         return (1);
 498                 }
 499         }
 500         return (0);
 501
 502 trunc:
 503         (void)printf("[|snap]");
 504         return (1);
 505 }
 506
 507
 508 /*
 509  * Local Variables:
 510  * c-style: whitesmith
 511  * c-basic-offset: 8
 512  * End:
 513  */