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 1.62 2005-04-25 17:56:43 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 };
  63
  64 static struct tok cmd2str[] = {
  65         { LLC_UI,       "ui" },
  66         { LLC_TEST,     "test" },
  67         { LLC_XID,      "xid" },
  68         { LLC_UA,       "ua" },
  69         { LLC_DISC,     "disc" },
  70         { LLC_DM,       "dm" },
  71         { LLC_SABME,    "sabme" },
  72         { LLC_FRMR,     "frmr" },
  73         { 0,            NULL }
  74 };
  75
  76 struct oui_tok {
  77         u_int32_t       oui;
  78         const struct tok *tok;
  79 };
  80
  81 static const struct tok bridged_values[] = {
  82     { PID_RFC2684_ETH_FCS,      "Ethernet + FCS" },
  83     { PID_RFC2684_ETH_NOFCS,    "Ethernet w/o FCS" },
  84     { PID_RFC2684_802_4_FCS,    "802.4 + FCS" },
  85     { PID_RFC2684_802_4_NOFCS,  "802.4 w/o FCS" },
  86     { PID_RFC2684_802_5_FCS,    "Token Ring + FCS" },
  87     { PID_RFC2684_802_5_NOFCS,  "Token Ring w/o FCS" },
  88     { PID_RFC2684_FDDI_FCS,     "FDDI + FCS" },
  89     { PID_RFC2684_FDDI_NOFCS,   "FDDI w/o FCS" },
  90     { PID_RFC2684_802_6_FCS,    "802.6 + FCS" },
  91     { PID_RFC2684_802_6_NOFCS,  "802.6 w/o FCS" },
  92     { PID_RFC2684_BPDU,         "BPDU" },
  93     { 0,                        NULL },
  94 };
  95
  96 static const struct oui_tok oui_to_tok[] = {
  97         { 0x000000, ethertype_values },
  98         { 0x0080C2, bridged_values },   /* bridged, RFC 2427 FR or RFC 2864 ATM */
  99         { 0, NULL }
 100 };
 101
 102 /*
 103  * Returns non-zero IFF it succeeds in printing the header
 104  */
 105 int
 106 llc_print(const u_char *p, u_int length, u_int caplen,
 107           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 108 {
 109         struct llc llc;
 110         register u_short et;
 111         u_int16_t control;
 112         register int ret;
 113
 114         if (caplen < 3) {
 115                 (void)printf("[|llc]");
 116                 default_print((u_char *)p, caplen);
 117                 return(0);
 118         }
 119
 120         /* Watch out for possible alignment problems */
 121         memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
 122
 123         if (eflag)
 124           printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x: ",
 125                  tok2str(llc_values,"Unknown",llc.dsap),
 126                  llc.dsap,
 127                  tok2str(llc_values,"Unknown",llc.ssap),
 128                  llc.ssap,
 129                  llc.llcu);
 130
 131         if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
 132                 /*
 133                  * This is an Ethernet_802.3 IPX frame; it has an
 134                  * 802.3 header (i.e., an Ethernet header where the
 135                  * type/length field is <= ETHERMTU, i.e. it's a length
 136                  * field, not a type field), but has no 802.2 header -
 137                  * the IPX packet starts right after the Ethernet header,
 138                  * with a signature of two bytes of 0xFF (which is
 139                  * LLCSAP_GLOBAL).
 140                  *
 141                  * (It might also have been an Ethernet_802.3 IPX at
 142                  * one time, but got bridged onto another network,
 143                  * such as an 802.11 network; this has appeared in at
 144                  * least one capture file.)
 145                  */
 146
 147             if (eflag)
 148                 printf("IPX-802.3: ");
 149
 150             ipx_print(p, length);
 151             return (1);
 152         }
 153
 154         if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
 155                 stp_print(p, length);
 156                 return (1);
 157         }
 158
 159         if (llc.ssap == LLCSAP_IP && llc.dsap == LLCSAP_IP) {
 160                 ip_print(gndo, p+4, length-4);
 161                 return (1);
 162         }
 163
 164         if (llc.ssap == LLCSAP_IPX && llc.dsap == LLCSAP_IPX &&
 165             llc.llcui == LLC_UI) {
 166                 /*
 167                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 168                  * header and an 802.2 LLC header with the source and
 169                  * destination SAPs being the IPX SAP.
 170                  *
 171                  * Skip DSAP, LSAP, and control field.
 172                  */
 173                 printf("(NOV-802.2) ");
 174                 p += 3;
 175                 length -= 3;
 176                 caplen -= 3;
 177                 ipx_print(p, length);
 178                 return (1);
 179         }
 180
 181 #ifdef TCPDUMP_DO_SMB
 182         if (llc.ssap == LLCSAP_NETBEUI && llc.dsap == LLCSAP_NETBEUI
 183             && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
 184                 /*
 185                  * we don't actually have a full netbeui parser yet, but the
 186                  * smb parser can handle many smb-in-netbeui packets, which
 187                  * is very useful, so we call that
 188                  *
 189                  * We don't call it for S frames, however, just I frames
 190                  * (which are frames that don't have the low-order bit,
 191                  * LLC_S_FMT, set in the first byte of the control field)
 192                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 193                  */
 194
 195                 /*
 196                  * Skip the DSAP and LSAP.
 197                  */
 198                 p += 2;
 199                 length -= 2;
 200                 caplen -= 2;
 201
 202                 /*
 203                  * OK, what type of LLC frame is this?  The length
 204                  * of the control field depends on that - I frames
 205                  * have a two-byte control field, and U frames have
 206                  * a one-byte control field.
 207                  */
 208                 if (llc.llcu == LLC_U_FMT) {
 209                         control = llc.llcu;
 210                         p += 1;
 211                         length -= 1;
 212                         caplen -= 1;
 213                 } else {
 214                         /*
 215                          * The control field in I and S frames is
 216                          * little-endian.
 217                          */
 218                         control = EXTRACT_LE_16BITS(&llc.llcu);
 219                         p += 2;
 220                         length -= 2;
 221                         caplen -= 2;
 222                 }
 223                 netbeui_print(control, p, length);
 224                 return (1);
 225         }
 226 #endif
 227         if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
 228             && llc.llcui == LLC_UI) {
 229                 isoclns_print(p + 3, length - 3, caplen - 3);
 230                 return (1);
 231         }
 232
 233         if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
 234             && llc.llcui == LLC_UI) {
 235                 u_int32_t orgcode;
 236
 237                 if (caplen < sizeof(llc)) {
 238                         (void)printf("[|llc-snap]");
 239                         default_print((u_char *)p, caplen);
 240                         return (0);
 241                 }
 242
 243                 caplen -= sizeof(llc);
 244                 length -= sizeof(llc);
 245                 p += sizeof(llc);
 246
 247                 orgcode = EXTRACT_24BITS(&llc.llc_orgcode[0]);
 248                 et = EXTRACT_16BITS(&llc.llc_ethertype[0]);
 249
 250                 if (eflag) {
 251                         const struct tok *tok = NULL;
 252                         const struct oui_tok *otp;
 253
 254                         for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 255                                 if (otp->oui == orgcode) {
 256                                         tok = otp->tok;
 257                                         break;
 258                                 }
 259                         }
 260                         (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 261                              tok2str(oui_values, "Unknown", orgcode),
 262                              orgcode,
 263                              (orgcode == 0x000000 ? "ethertype" : "pid"),
 264                              tok2str(tok, "Unknown", et),
 265                              et);
 266                 }
 267
 268                 /*
 269                  * XXX - what *is* the right bridge pad value here?
 270                  * Does anybody ever bridge one form of LAN traffic
 271                  * over a networking type that uses 802.2 LLC?
 272                  */
 273                 ret = snap_print(p, length, caplen, extracted_ethertype,
 274                     orgcode, et, 2);
 275                 if (ret)
 276                         return (ret);
 277         }
 278
 279         if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
 280                 if (eflag || esrc == NULL || edst == NULL)
 281                         (void)printf("%s ", llcsap_string(llc.dsap));
 282                 else
 283                         (void)printf("%s > %s %s ",
 284                                         etheraddr_string(esrc),
 285                                         etheraddr_string(edst),
 286                                         llcsap_string(llc.dsap));
 287         } else {
 288                 if (eflag || esrc == NULL || edst == NULL)
 289                         (void)printf("%s > %s ",
 290                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 291                                 llcsap_string(llc.dsap));
 292                 else
 293                         (void)printf("%s %s > %s %s ",
 294                                 etheraddr_string(esrc),
 295                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 296                                 etheraddr_string(edst),
 297                                 llcsap_string(llc.dsap));
 298         }
 299
 300         if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
 301                 u_int16_t cmd;
 302                 const char *m;
 303                 char f;
 304
 305                 cmd = LLC_U_CMD(llc.llcu);
 306                 m = tok2str(cmd2str, "%02x", cmd);
 307                 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
 308                         case 0:                 f = 'C'; break;
 309                         case LLC_GSAP:          f = 'R'; break;
 310                         case LLC_U_POLL:        f = 'P'; break;
 311                         case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
 312                         default:                f = '?'; break;
 313                 }
 314
 315                 printf("%s/%c", m, f);
 316
 317                 p += 3;
 318                 length -= 3;
 319                 caplen -= 3;
 320
 321                 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
 322                         if (*p == LLC_XID_FI) {
 323                                 printf(": %02x %02x", p[1], p[2]);
 324                                 p += 3;
 325                                 length -= 3;
 326                                 caplen -= 3;
 327                         }
 328                 }
 329         } else {
 330                 char f;
 331
 332                 /*
 333                  * The control field in I and S frames is little-endian.
 334                  */
 335                 control = EXTRACT_LE_16BITS(&llc.llcu);
 336                 switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
 337                         case 0:                 f = 'C'; break;
 338                         case LLC_GSAP:          f = 'R'; break;
 339                         case LLC_IS_POLL:       f = 'P'; break;
 340                         case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
 341                         default:                f = '?'; break;
 342                 }
 343
 344                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 345                         static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
 346                         (void)printf("%s (r=%d,%c)",
 347                                 llc_s[LLC_S_CMD(control)],
 348                                 LLC_IS_NR(control),
 349                                 f);
 350                 } else {
 351                         (void)printf("I (s=%d,r=%d,%c)",
 352                                 LLC_I_NS(control),
 353                                 LLC_IS_NR(control),
 354                                 f);
 355                 }
 356                 p += 4;
 357                 length -= 4;
 358                 caplen -= 4;
 359         }
 360         return(1);
 361 }
 362
 363 int
 364 snap_print(const u_char *p, u_int length, u_int caplen,
 365     u_short *extracted_ethertype, u_int32_t orgcode, u_short et,
 366     u_int bridge_pad)
 367 {
 368         register int ret;
 369
 370         switch (orgcode) {
 371         case OUI_ENCAP_ETHER:
 372         case OUI_CISCO_90:
 373                 /*
 374                  * This is an encapsulated Ethernet packet,
 375                  * or a packet bridged by some piece of
 376                  * Cisco hardware; the protocol ID is
 377                  * an Ethernet protocol type.
 378                  */
 379                 ret = ether_encap_print(et, p, length, caplen,
 380                     extracted_ethertype);
 381                 if (ret)
 382                         return (ret);
 383                 break;
 384
 385         case OUI_APPLETALK:
 386                 if (et == ETHERTYPE_ATALK) {
 387                         /*
 388                          * No, I have no idea why Apple used one
 389                          * of their own OUIs, rather than
 390                          * 0x000000, and an Ethernet packet
 391                          * type, for Appletalk data packets,
 392                          * but used 0x000000 and an Ethernet
 393                          * packet type for AARP packets.
 394                          */
 395                         ret = ether_encap_print(et, p, length, caplen,
 396                             extracted_ethertype);
 397                         if (ret)
 398                                 return (ret);
 399                 }
 400                 break;
 401
 402         case OUI_CISCO:
 403                 if (et == PID_CISCO_CDP) {
 404                         cdp_print(p, length, caplen);
 405                         return (1);
 406                 }
 407                 break;
 408
 409         case OUI_RFC2684:
 410                 switch (et) {
 411
 412                 case PID_RFC2684_ETH_FCS:
 413                 case PID_RFC2684_ETH_NOFCS:
 414                         /*
 415                          * XXX - remove the last two bytes for
 416                          * PID_RFC2684_ETH_FCS?
 417                          */
 418                         /*
 419                          * Skip the padding.
 420                          */
 421                         caplen -= bridge_pad;
 422                         length -= bridge_pad;
 423                         p += bridge_pad;
 424
 425                         /*
 426                          * What remains is an Ethernet packet.
 427                          */
 428                         ether_print(p, length, caplen);
 429                         return (1);
 430
 431                 case PID_RFC2684_802_5_FCS:
 432                 case PID_RFC2684_802_5_NOFCS:
 433                         /*
 434                          * XXX - remove the last two bytes for
 435                          * PID_RFC2684_ETH_FCS?
 436                          */
 437                         /*
 438                          * Skip the padding, but not the Access
 439                          * Control field.
 440                          */
 441                         caplen -= bridge_pad;
 442                         length -= bridge_pad;
 443                         p += bridge_pad;
 444
 445                         /*
 446                          * What remains is an 802.5 Token Ring
 447                          * packet.
 448                          */
 449                         token_print(p, length, caplen);
 450                         return (1);
 451
 452                 case PID_RFC2684_FDDI_FCS:
 453                 case PID_RFC2684_FDDI_NOFCS:
 454                         /*
 455                          * XXX - remove the last two bytes for
 456                          * PID_RFC2684_ETH_FCS?
 457                          */
 458                         /*
 459                          * Skip the padding.
 460                          */
 461                         caplen -= bridge_pad + 1;
 462                         length -= bridge_pad + 1;
 463                         p += bridge_pad + 1;
 464
 465                         /*
 466                          * What remains is an FDDI packet.
 467                          */
 468                         fddi_print(p, length, caplen);
 469                         return (1);
 470
 471                 case PID_RFC2684_BPDU:
 472                         stp_print(p, length);
 473                         return (1);
 474                 }
 475         }
 476         return (0);
 477 }
 478
 479
 480 /*
 481  * Local Variables:
 482  * c-style: whitesmith
 483  * c-basic-offset: 8
 484  * End:
 485  */