contrib/tcpdump/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  * $FreeBSD$
  25  */
  26
  27 #ifndef lint
  28 static const char rcsid[] _U_ =
  29     "@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.53.2.3 2003/12/29 22:33:18 hannes Exp $";
  30 #endif
  31
  32 #ifdef HAVE_CONFIG_H
  33 #include "config.h"
  34 #endif
  35
  36 #include <tcpdump-stdinc.h>
  37
  38 #include <stdio.h>
  39 #include <string.h>
  40
  41 #include "interface.h"
  42 #include "addrtoname.h"
  43 #include "extract.h"                    /* must come after interface.h */
  44
  45 #include "llc.h"
  46 #include "ethertype.h"
  47
  48 static struct tok llc_values[] = {
  49         { LLCSAP_NULL,     "Null" },
  50         { LLCSAP_GLOBAL,   "Global" },
  51         { LLCSAP_8021B_I,  "802.1B I" },
  52         { LLCSAP_8021B_G,  "802.1B G" },
  53         { LLCSAP_IP,       "IP" },
  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 };
  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 /*
  78  * Returns non-zero IFF it succeeds in printing the header
  79  */
  80 int
  81 llc_print(const u_char *p, u_int length, u_int caplen,
  82           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
  83 {
  84         struct llc llc;
  85         register u_short et;
  86         u_int16_t control;
  87         register int ret;
  88
  89         if (caplen < 3) {
  90                 (void)printf("[|llc]");
  91                 default_print((u_char *)p, caplen);
  92                 return(0);
  93         }
  94
  95         /* Watch out for possible alignment problems */
  96         memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
  97
  98         if (eflag)
  99           printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x, ",
 100                  tok2str(llc_values,"Unknown",llc.dsap),
 101                  llc.dsap,
 102                  tok2str(llc_values,"Unknown",llc.ssap),
 103                  llc.ssap,
 104                  llc.llcu);
 105
 106         if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
 107                 /*
 108                  * This is an Ethernet_802.3 IPX frame; it has an
 109                  * 802.3 header (i.e., an Ethernet header where the
 110                  * type/length field is <= ETHERMTU, i.e. it's a length
 111                  * field, not a type field), but has no 802.2 header -
 112                  * the IPX packet starts right after the Ethernet header,
 113                  * with a signature of two bytes of 0xFF (which is
 114                  * LLCSAP_GLOBAL).
 115                  *
 116                  * (It might also have been an Ethernet_802.3 IPX at
 117                  * one time, but got bridged onto another network,
 118                  * such as an 802.11 network; this has appeared in at
 119                  * least one capture file.)
 120                  */
 121                 printf("(NOV-802.3) ");
 122                 ipx_print(p, length);
 123                 return (1);
 124         }
 125
 126         if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
 127                 stp_print(p, length);
 128                 return (1);
 129         }
 130
 131         if (llc.ssap == LLCSAP_IP && llc.dsap == LLCSAP_IP) {
 132                 ip_print(p+4, length-4);
 133                 return (1);
 134         }
 135
 136         if (llc.ssap == LLCSAP_IPX && llc.dsap == LLCSAP_IPX &&
 137             llc.llcui == LLC_UI) {
 138                 /*
 139                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 140                  * header and an 802.2 LLC header with the source and
 141                  * destination SAPs being the IPX SAP.
 142                  *
 143                  * Skip DSAP, LSAP, and control field.
 144                  */
 145                 printf("(NOV-802.2) ");
 146                 p += 3;
 147                 length -= 3;
 148                 caplen -= 3;
 149                 ipx_print(p, length);
 150                 return (1);
 151         }
 152
 153 #ifdef TCPDUMP_DO_SMB
 154         if (llc.ssap == LLCSAP_NETBEUI && llc.dsap == LLCSAP_NETBEUI
 155             && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
 156                 /*
 157                  * we don't actually have a full netbeui parser yet, but the
 158                  * smb parser can handle many smb-in-netbeui packets, which
 159                  * is very useful, so we call that
 160                  *
 161                  * We don't call it for S frames, however, just I frames
 162                  * (which are frames that don't have the low-order bit,
 163                  * LLC_S_FMT, set in the first byte of the control field)
 164                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 165                  */
 166
 167                 /*
 168                  * Skip the DSAP and LSAP.
 169                  */
 170                 p += 2;
 171                 length -= 2;
 172                 caplen -= 2;
 173
 174                 /*
 175                  * OK, what type of LLC frame is this?  The length
 176                  * of the control field depends on that - I frames
 177                  * have a two-byte control field, and U frames have
 178                  * a one-byte control field.
 179                  */
 180                 if (llc.llcu == LLC_U_FMT) {
 181                         control = llc.llcu;
 182                         p += 1;
 183                         length -= 1;
 184                         caplen -= 1;
 185                 } else {
 186                         /*
 187                          * The control field in I and S frames is
 188                          * little-endian.
 189                          */
 190                         control = EXTRACT_LE_16BITS(&llc.llcu);
 191                         p += 2;
 192                         length -= 2;
 193                         caplen -= 2;
 194                 }
 195                 netbeui_print(control, p, length);
 196                 return (1);
 197         }
 198 #endif
 199         if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
 200             && llc.llcui == LLC_UI) {
 201                 isoclns_print(p + 3, length - 3, caplen - 3);
 202                 return (1);
 203         }
 204
 205         if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
 206             && llc.llcui == LLC_UI) {
 207                 u_int32_t orgcode;
 208
 209                 if (caplen < sizeof(llc)) {
 210                         (void)printf("[|llc-snap]");
 211                         default_print((u_char *)p, caplen);
 212                         return (0);
 213                 }
 214
 215                 caplen -= sizeof(llc);
 216                 length -= sizeof(llc);
 217                 p += sizeof(llc);
 218
 219                 orgcode = EXTRACT_24BITS(&llc.llc_orgcode[0]);
 220                 et = EXTRACT_16BITS(&llc.llc_ethertype[0]);
 221                 /*
 222                  * XXX - what *is* the right bridge pad value here?
 223                  * Does anybody ever bridge one form of LAN traffic
 224                  * over a networking type that uses 802.2 LLC?
 225                  */
 226                 ret = snap_print(p, length, caplen, extracted_ethertype,
 227                     orgcode, et, 2);
 228                 if (ret)
 229                         return (ret);
 230         }
 231
 232         if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
 233                 if (eflag || esrc == NULL || edst == NULL)
 234                         (void)printf("%s ", llcsap_string(llc.dsap));
 235                 else
 236                         (void)printf("%s > %s %s ",
 237                                         etheraddr_string(esrc),
 238                                         etheraddr_string(edst),
 239                                         llcsap_string(llc.dsap));
 240         } else {
 241                 if (eflag || esrc == NULL || edst == NULL)
 242                         (void)printf("%s > %s ",
 243                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 244                                 llcsap_string(llc.dsap));
 245                 else
 246                         (void)printf("%s %s > %s %s ",
 247                                 etheraddr_string(esrc),
 248                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 249                                 etheraddr_string(edst),
 250                                 llcsap_string(llc.dsap));
 251         }
 252
 253         if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
 254                 u_int16_t cmd;
 255                 const char *m;
 256                 char f;
 257
 258                 cmd = LLC_U_CMD(llc.llcu);
 259                 m = tok2str(cmd2str, "%02x", cmd);
 260                 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
 261                         case 0:                 f = 'C'; break;
 262                         case LLC_GSAP:          f = 'R'; break;
 263                         case LLC_U_POLL:        f = 'P'; break;
 264                         case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
 265                         default:                f = '?'; break;
 266                 }
 267
 268                 printf("%s/%c", m, f);
 269
 270                 p += 3;
 271                 length -= 3;
 272                 caplen -= 3;
 273
 274                 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
 275                         if (*p == LLC_XID_FI) {
 276                                 printf(": %02x %02x", p[1], p[2]);
 277                                 p += 3;
 278                                 length -= 3;
 279                                 caplen -= 3;
 280                         }
 281                 }
 282         } else {
 283                 char f;
 284
 285                 /*
 286                  * The control field in I and S frames is little-endian.
 287                  */
 288                 control = EXTRACT_LE_16BITS(&llc.llcu);
 289                 switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
 290                         case 0:                 f = 'C'; break;
 291                         case LLC_GSAP:          f = 'R'; break;
 292                         case LLC_IS_POLL:       f = 'P'; break;
 293                         case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
 294                         default:                f = '?'; break;
 295                 }
 296
 297                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 298                         static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
 299                         (void)printf("%s (r=%d,%c)",
 300                                 llc_s[LLC_S_CMD(control)],
 301                                 LLC_IS_NR(control),
 302                                 f);
 303                 } else {
 304                         (void)printf("I (s=%d,r=%d,%c)",
 305                                 LLC_I_NS(control),
 306                                 LLC_IS_NR(control),
 307                                 f);
 308                 }
 309                 p += 4;
 310                 length -= 4;
 311                 caplen -= 4;
 312         }
 313         (void)printf(" len=%d", length);
 314         return(1);
 315 }
 316
 317 int
 318 snap_print(const u_char *p, u_int length, u_int caplen,
 319     u_short *extracted_ethertype, u_int32_t orgcode, u_short et,
 320     u_int bridge_pad)
 321 {
 322         register int ret;
 323
 324         switch (orgcode) {
 325         case OUI_ENCAP_ETHER:
 326         case OUI_CISCO_90:
 327                 /*
 328                  * This is an encapsulated Ethernet packet,
 329                  * or a packet bridged by some piece of
 330                  * Cisco hardware; the protocol ID is
 331                  * an Ethernet protocol type.
 332                  */
 333                 ret = ether_encap_print(et, p, length, caplen,
 334                     extracted_ethertype);
 335                 if (ret)
 336                         return (ret);
 337                 break;
 338
 339         case OUI_APPLETALK:
 340                 if (et == ETHERTYPE_ATALK) {
 341                         /*
 342                          * No, I have no idea why Apple used one
 343                          * of their own OUIs, rather than
 344                          * 0x000000, and an Ethernet packet
 345                          * type, for Appletalk data packets,
 346                          * but used 0x000000 and an Ethernet
 347                          * packet type for AARP packets.
 348                          */
 349                         ret = ether_encap_print(et, p, length, caplen,
 350                             extracted_ethertype);
 351                         if (ret)
 352                                 return (ret);
 353                 }
 354                 break;
 355
 356         case OUI_CISCO:
 357                 if (et == PID_CISCO_CDP) {
 358                         cdp_print(p, length, caplen);
 359                         return (1);
 360                 }
 361                 break;
 362
 363         case OUI_RFC2684:
 364                 switch (et) {
 365
 366                 case PID_RFC2684_ETH_FCS:
 367                 case PID_RFC2684_ETH_NOFCS:
 368                         /*
 369                          * XXX - remove the last two bytes for
 370                          * PID_RFC2684_ETH_FCS?
 371                          */
 372                         /*
 373                          * Skip the padding.
 374                          */
 375                         caplen -= bridge_pad;
 376                         length -= bridge_pad;
 377                         p += bridge_pad;
 378
 379                         /*
 380                          * What remains is an Ethernet packet.
 381                          */
 382                         ether_print(p, length, caplen);
 383                         return (1);
 384
 385                 case PID_RFC2684_802_5_FCS:
 386                 case PID_RFC2684_802_5_NOFCS:
 387                         /*
 388                          * XXX - remove the last two bytes for
 389                          * PID_RFC2684_ETH_FCS?
 390                          */
 391                         /*
 392                          * Skip the padding, but not the Access
 393                          * Control field.
 394                          */
 395                         caplen -= bridge_pad;
 396                         length -= bridge_pad;
 397                         p += bridge_pad;
 398
 399                         /*
 400                          * What remains is an 802.5 Token Ring
 401                          * packet.
 402                          */
 403                         token_print(p, length, caplen);
 404                         return (1);
 405
 406                 case PID_RFC2684_FDDI_FCS:
 407                 case PID_RFC2684_FDDI_NOFCS:
 408                         /*
 409                          * XXX - remove the last two bytes for
 410                          * PID_RFC2684_ETH_FCS?
 411                          */
 412                         /*
 413                          * Skip the padding.
 414                          */
 415                         caplen -= bridge_pad + 1;
 416                         length -= bridge_pad + 1;
 417                         p += bridge_pad + 1;
 418
 419                         /*
 420                          * What remains is an FDDI packet.
 421                          */
 422                         fddi_print(p, length, caplen);
 423                         return (1);
 424
 425                 case PID_RFC2684_BPDU:
 426                         stp_print(p, length);
 427                         return (1);
 428                 }
 429         }
 430         return (0);
 431 }