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 1.61 2005-04-06 21:32:41 mcr 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 /*
  77  * Returns non-zero IFF it succeeds in printing the header
  78  */
  79 int
  80 llc_print(const u_char *p, u_int length, u_int caplen,
  81           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
  82 {
  83         struct llc llc;
  84         register u_short et;
  85         u_int16_t control;
  86         register int ret;
  87
  88         if (caplen < 3) {
  89                 (void)printf("[|llc]");
  90                 default_print((u_char *)p, caplen);
  91                 return(0);
  92         }
  93
  94         /* Watch out for possible alignment problems */
  95         memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
  96
  97         if (eflag)
  98           printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x: ",
  99                  tok2str(llc_values,"Unknown",llc.dsap),
 100                  llc.dsap,
 101                  tok2str(llc_values,"Unknown",llc.ssap),
 102                  llc.ssap,
 103                  llc.llcu);
 104
 105         if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
 106                 /*
 107                  * This is an Ethernet_802.3 IPX frame; it has an
 108                  * 802.3 header (i.e., an Ethernet header where the
 109                  * type/length field is <= ETHERMTU, i.e. it's a length
 110                  * field, not a type field), but has no 802.2 header -
 111                  * the IPX packet starts right after the Ethernet header,
 112                  * with a signature of two bytes of 0xFF (which is
 113                  * LLCSAP_GLOBAL).
 114                  *
 115                  * (It might also have been an Ethernet_802.3 IPX at
 116                  * one time, but got bridged onto another network,
 117                  * such as an 802.11 network; this has appeared in at
 118                  * least one capture file.)
 119                  */
 120
 121             if (eflag)
 122                 printf("IPX-802.3: ");
 123
 124             ipx_print(p, length);
 125             return (1);
 126         }
 127
 128         if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
 129                 stp_print(p, length);
 130                 return (1);
 131         }
 132
 133         if (llc.ssap == LLCSAP_IP && llc.dsap == LLCSAP_IP) {
 134                 ip_print(gndo, p+4, length-4);
 135                 return (1);
 136         }
 137
 138         if (llc.ssap == LLCSAP_IPX && llc.dsap == LLCSAP_IPX &&
 139             llc.llcui == LLC_UI) {
 140                 /*
 141                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 142                  * header and an 802.2 LLC header with the source and
 143                  * destination SAPs being the IPX SAP.
 144                  *
 145                  * Skip DSAP, LSAP, and control field.
 146                  */
 147                 printf("(NOV-802.2) ");
 148                 p += 3;
 149                 length -= 3;
 150                 caplen -= 3;
 151                 ipx_print(p, length);
 152                 return (1);
 153         }
 154
 155 #ifdef TCPDUMP_DO_SMB
 156         if (llc.ssap == LLCSAP_NETBEUI && llc.dsap == LLCSAP_NETBEUI
 157             && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
 158                 /*
 159                  * we don't actually have a full netbeui parser yet, but the
 160                  * smb parser can handle many smb-in-netbeui packets, which
 161                  * is very useful, so we call that
 162                  *
 163                  * We don't call it for S frames, however, just I frames
 164                  * (which are frames that don't have the low-order bit,
 165                  * LLC_S_FMT, set in the first byte of the control field)
 166                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 167                  */
 168
 169                 /*
 170                  * Skip the DSAP and LSAP.
 171                  */
 172                 p += 2;
 173                 length -= 2;
 174                 caplen -= 2;
 175
 176                 /*
 177                  * OK, what type of LLC frame is this?  The length
 178                  * of the control field depends on that - I frames
 179                  * have a two-byte control field, and U frames have
 180                  * a one-byte control field.
 181                  */
 182                 if (llc.llcu == LLC_U_FMT) {
 183                         control = llc.llcu;
 184                         p += 1;
 185                         length -= 1;
 186                         caplen -= 1;
 187                 } else {
 188                         /*
 189                          * The control field in I and S frames is
 190                          * little-endian.
 191                          */
 192                         control = EXTRACT_LE_16BITS(&llc.llcu);
 193                         p += 2;
 194                         length -= 2;
 195                         caplen -= 2;
 196                 }
 197                 netbeui_print(control, p, length);
 198                 return (1);
 199         }
 200 #endif
 201         if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
 202             && llc.llcui == LLC_UI) {
 203                 isoclns_print(p + 3, length - 3, caplen - 3);
 204                 return (1);
 205         }
 206
 207         if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
 208             && llc.llcui == LLC_UI) {
 209                 u_int32_t orgcode;
 210
 211                 if (caplen < sizeof(llc)) {
 212                         (void)printf("[|llc-snap]");
 213                         default_print((u_char *)p, caplen);
 214                         return (0);
 215                 }
 216
 217                 caplen -= sizeof(llc);
 218                 length -= sizeof(llc);
 219                 p += sizeof(llc);
 220
 221                 orgcode = EXTRACT_24BITS(&llc.llc_orgcode[0]);
 222                 et = EXTRACT_16BITS(&llc.llc_ethertype[0]);
 223
 224                 if (eflag)
 225                     (void)printf("oui %s (0x%06x), ethertype %s (0x%04x): ",
 226                                  tok2str(oui_values,"Unknown",orgcode),
 227                                  orgcode,
 228                                  tok2str(ethertype_values,"Unknown", et),
 229                                  et);
 230
 231                 /*
 232                  * XXX - what *is* the right bridge pad value here?
 233                  * Does anybody ever bridge one form of LAN traffic
 234                  * over a networking type that uses 802.2 LLC?
 235                  */
 236                 ret = snap_print(p, length, caplen, extracted_ethertype,
 237                     orgcode, et, 2);
 238                 if (ret)
 239                         return (ret);
 240         }
 241
 242         if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
 243                 if (eflag || esrc == NULL || edst == NULL)
 244                         (void)printf("%s ", llcsap_string(llc.dsap));
 245                 else
 246                         (void)printf("%s > %s %s ",
 247                                         etheraddr_string(esrc),
 248                                         etheraddr_string(edst),
 249                                         llcsap_string(llc.dsap));
 250         } else {
 251                 if (eflag || esrc == NULL || edst == NULL)
 252                         (void)printf("%s > %s ",
 253                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 254                                 llcsap_string(llc.dsap));
 255                 else
 256                         (void)printf("%s %s > %s %s ",
 257                                 etheraddr_string(esrc),
 258                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 259                                 etheraddr_string(edst),
 260                                 llcsap_string(llc.dsap));
 261         }
 262
 263         if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
 264                 u_int16_t cmd;
 265                 const char *m;
 266                 char f;
 267
 268                 cmd = LLC_U_CMD(llc.llcu);
 269                 m = tok2str(cmd2str, "%02x", cmd);
 270                 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
 271                         case 0:                 f = 'C'; break;
 272                         case LLC_GSAP:          f = 'R'; break;
 273                         case LLC_U_POLL:        f = 'P'; break;
 274                         case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
 275                         default:                f = '?'; break;
 276                 }
 277
 278                 printf("%s/%c", m, f);
 279
 280                 p += 3;
 281                 length -= 3;
 282                 caplen -= 3;
 283
 284                 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
 285                         if (*p == LLC_XID_FI) {
 286                                 printf(": %02x %02x", p[1], p[2]);
 287                                 p += 3;
 288                                 length -= 3;
 289                                 caplen -= 3;
 290                         }
 291                 }
 292         } else {
 293                 char f;
 294
 295                 /*
 296                  * The control field in I and S frames is little-endian.
 297                  */
 298                 control = EXTRACT_LE_16BITS(&llc.llcu);
 299                 switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
 300                         case 0:                 f = 'C'; break;
 301                         case LLC_GSAP:          f = 'R'; break;
 302                         case LLC_IS_POLL:       f = 'P'; break;
 303                         case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
 304                         default:                f = '?'; break;
 305                 }
 306
 307                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 308                         static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
 309                         (void)printf("%s (r=%d,%c)",
 310                                 llc_s[LLC_S_CMD(control)],
 311                                 LLC_IS_NR(control),
 312                                 f);
 313                 } else {
 314                         (void)printf("I (s=%d,r=%d,%c)",
 315                                 LLC_I_NS(control),
 316                                 LLC_IS_NR(control),
 317                                 f);
 318                 }
 319                 p += 4;
 320                 length -= 4;
 321                 caplen -= 4;
 322         }
 323         return(1);
 324 }
 325
 326 int
 327 snap_print(const u_char *p, u_int length, u_int caplen,
 328     u_short *extracted_ethertype, u_int32_t orgcode, u_short et,
 329     u_int bridge_pad)
 330 {
 331         register int ret;
 332
 333         switch (orgcode) {
 334         case OUI_ENCAP_ETHER:
 335         case OUI_CISCO_90:
 336                 /*
 337                  * This is an encapsulated Ethernet packet,
 338                  * or a packet bridged by some piece of
 339                  * Cisco hardware; the protocol ID is
 340                  * an Ethernet protocol type.
 341                  */
 342                 ret = ether_encap_print(et, p, length, caplen,
 343                     extracted_ethertype);
 344                 if (ret)
 345                         return (ret);
 346                 break;
 347
 348         case OUI_APPLETALK:
 349                 if (et == ETHERTYPE_ATALK) {
 350                         /*
 351                          * No, I have no idea why Apple used one
 352                          * of their own OUIs, rather than
 353                          * 0x000000, and an Ethernet packet
 354                          * type, for Appletalk data packets,
 355                          * but used 0x000000 and an Ethernet
 356                          * packet type for AARP packets.
 357                          */
 358                         ret = ether_encap_print(et, p, length, caplen,
 359                             extracted_ethertype);
 360                         if (ret)
 361                                 return (ret);
 362                 }
 363                 break;
 364
 365         case OUI_CISCO:
 366                 if (et == PID_CISCO_CDP) {
 367                         cdp_print(p, length, caplen);
 368                         return (1);
 369                 }
 370                 break;
 371
 372         case OUI_RFC2684:
 373                 switch (et) {
 374
 375                 case PID_RFC2684_ETH_FCS:
 376                 case PID_RFC2684_ETH_NOFCS:
 377                         /*
 378                          * XXX - remove the last two bytes for
 379                          * PID_RFC2684_ETH_FCS?
 380                          */
 381                         /*
 382                          * Skip the padding.
 383                          */
 384                         caplen -= bridge_pad;
 385                         length -= bridge_pad;
 386                         p += bridge_pad;
 387
 388                         /*
 389                          * What remains is an Ethernet packet.
 390                          */
 391                         ether_print(p, length, caplen);
 392                         return (1);
 393
 394                 case PID_RFC2684_802_5_FCS:
 395                 case PID_RFC2684_802_5_NOFCS:
 396                         /*
 397                          * XXX - remove the last two bytes for
 398                          * PID_RFC2684_ETH_FCS?
 399                          */
 400                         /*
 401                          * Skip the padding, but not the Access
 402                          * Control field.
 403                          */
 404                         caplen -= bridge_pad;
 405                         length -= bridge_pad;
 406                         p += bridge_pad;
 407
 408                         /*
 409                          * What remains is an 802.5 Token Ring
 410                          * packet.
 411                          */
 412                         token_print(p, length, caplen);
 413                         return (1);
 414
 415                 case PID_RFC2684_FDDI_FCS:
 416                 case PID_RFC2684_FDDI_NOFCS:
 417                         /*
 418                          * XXX - remove the last two bytes for
 419                          * PID_RFC2684_ETH_FCS?
 420                          */
 421                         /*
 422                          * Skip the padding.
 423                          */
 424                         caplen -= bridge_pad + 1;
 425                         length -= bridge_pad + 1;
 426                         p += bridge_pad + 1;
 427
 428                         /*
 429                          * What remains is an FDDI packet.
 430                          */
 431                         fddi_print(p, length, caplen);
 432                         return (1);
 433
 434                 case PID_RFC2684_BPDU:
 435                         stp_print(p, length);
 436                         return (1);
 437                 }
 438         }
 439         return (0);
 440 }
 441
 442
 443 /*
 444  * Local Variables:
 445  * c-style: whitesmith
 446  * c-basic-offset: 8
 447  * End:
 448  */