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 1.53.2.3 2003-12-29 22:33:18 hannes 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
  46 static struct tok llc_values[] = {
  47         { LLCSAP_NULL,     "Null" },
  48         { LLCSAP_GLOBAL,   "Global" },
  49         { LLCSAP_8021B_I,  "802.1B I" },
  50         { LLCSAP_8021B_G,  "802.1B G" },
  51         { LLCSAP_IP,       "IP" },
  52         { LLCSAP_PROWAYNM, "ProWay NM" },
  53         { LLCSAP_8021D,    "STP" },
  54         { LLCSAP_RS511,    "RS511" },
  55         { LLCSAP_ISO8208,  "ISO8208" },
  56         { LLCSAP_PROWAY,   "ProWay" },
  57         { LLCSAP_SNAP,     "SNAP" },
  58         { LLCSAP_IPX,      "IPX" },
  59         { LLCSAP_NETBEUI,  "NetBeui" },
  60         { LLCSAP_ISONS,    "OSI" },
  61 };
  62
  63 static struct tok cmd2str[] = {
  64         { LLC_UI,       "ui" },
  65         { LLC_TEST,     "test" },
  66         { LLC_XID,      "xid" },
  67         { LLC_UA,       "ua" },
  68         { LLC_DISC,     "disc" },
  69         { LLC_DM,       "dm" },
  70         { LLC_SABME,    "sabme" },
  71         { LLC_FRMR,     "frmr" },
  72         { 0,            NULL }
  73 };
  74
  75 /*
  76  * Returns non-zero IFF it succeeds in printing the header
  77  */
  78 int
  79 llc_print(const u_char *p, u_int length, u_int caplen,
  80           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
  81 {
  82         struct llc llc;
  83         register u_short et;
  84         u_int16_t control;
  85         register int ret;
  86
  87         if (caplen < 3) {
  88                 (void)printf("[|llc]");
  89                 default_print((u_char *)p, caplen);
  90                 return(0);
  91         }
  92
  93         /* Watch out for possible alignment problems */
  94         memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
  95
  96         if (eflag)
  97           printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x, ",
  98                  tok2str(llc_values,"Unknown",llc.dsap),
  99                  llc.dsap,
 100                  tok2str(llc_values,"Unknown",llc.ssap),
 101                  llc.ssap,
 102                  llc.llcu);
 103
 104         if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
 105                 /*
 106                  * This is an Ethernet_802.3 IPX frame; it has an
 107                  * 802.3 header (i.e., an Ethernet header where the
 108                  * type/length field is <= ETHERMTU, i.e. it's a length
 109                  * field, not a type field), but has no 802.2 header -
 110                  * the IPX packet starts right after the Ethernet header,
 111                  * with a signature of two bytes of 0xFF (which is
 112                  * LLCSAP_GLOBAL).
 113                  *
 114                  * (It might also have been an Ethernet_802.3 IPX at
 115                  * one time, but got bridged onto another network,
 116                  * such as an 802.11 network; this has appeared in at
 117                  * least one capture file.)
 118                  */
 119                 printf("(NOV-802.3) ");
 120                 ipx_print(p, length);
 121                 return (1);
 122         }
 123
 124         if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
 125                 stp_print(p, length);
 126                 return (1);
 127         }
 128
 129         if (llc.ssap == LLCSAP_IP && llc.dsap == LLCSAP_IP) {
 130                 ip_print(p+4, length-4);
 131                 return (1);
 132         }
 133
 134         if (llc.ssap == LLCSAP_IPX && llc.dsap == LLCSAP_IPX &&
 135             llc.llcui == LLC_UI) {
 136                 /*
 137                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 138                  * header and an 802.2 LLC header with the source and
 139                  * destination SAPs being the IPX SAP.
 140                  *
 141                  * Skip DSAP, LSAP, and control field.
 142                  */
 143                 printf("(NOV-802.2) ");
 144                 p += 3;
 145                 length -= 3;
 146                 caplen -= 3;
 147                 ipx_print(p, length);
 148                 return (1);
 149         }
 150
 151 #ifdef TCPDUMP_DO_SMB
 152         if (llc.ssap == LLCSAP_NETBEUI && llc.dsap == LLCSAP_NETBEUI
 153             && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
 154                 /*
 155                  * we don't actually have a full netbeui parser yet, but the
 156                  * smb parser can handle many smb-in-netbeui packets, which
 157                  * is very useful, so we call that
 158                  *
 159                  * We don't call it for S frames, however, just I frames
 160                  * (which are frames that don't have the low-order bit,
 161                  * LLC_S_FMT, set in the first byte of the control field)
 162                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 163                  */
 164
 165                 /*
 166                  * Skip the DSAP and LSAP.
 167                  */
 168                 p += 2;
 169                 length -= 2;
 170                 caplen -= 2;
 171
 172                 /*
 173                  * OK, what type of LLC frame is this?  The length
 174                  * of the control field depends on that - I frames
 175                  * have a two-byte control field, and U frames have
 176                  * a one-byte control field.
 177                  */
 178                 if (llc.llcu == LLC_U_FMT) {
 179                         control = llc.llcu;
 180                         p += 1;
 181                         length -= 1;
 182                         caplen -= 1;
 183                 } else {
 184                         /*
 185                          * The control field in I and S frames is
 186                          * little-endian.
 187                          */
 188                         control = EXTRACT_LE_16BITS(&llc.llcu);
 189                         p += 2;
 190                         length -= 2;
 191                         caplen -= 2;
 192                 }
 193                 netbeui_print(control, p, length);
 194                 return (1);
 195         }
 196 #endif
 197         if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
 198             && llc.llcui == LLC_UI) {
 199                 isoclns_print(p + 3, length - 3, caplen - 3);
 200                 return (1);
 201         }
 202
 203         if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
 204             && llc.llcui == LLC_UI) {
 205                 u_int32_t orgcode;
 206
 207                 if (caplen < sizeof(llc)) {
 208                         (void)printf("[|llc-snap]");
 209                         default_print((u_char *)p, caplen);
 210                         return (0);
 211                 }
 212
 213                 caplen -= sizeof(llc);
 214                 length -= sizeof(llc);
 215                 p += sizeof(llc);
 216
 217                 orgcode = EXTRACT_24BITS(&llc.llc_orgcode[0]);
 218                 et = EXTRACT_16BITS(&llc.llc_ethertype[0]);
 219                 /*
 220                  * XXX - what *is* the right bridge pad value here?
 221                  * Does anybody ever bridge one form of LAN traffic
 222                  * over a networking type that uses 802.2 LLC?
 223                  */
 224                 ret = snap_print(p, length, caplen, extracted_ethertype,
 225                     orgcode, et, 2);
 226                 if (ret)
 227                         return (ret);
 228         }
 229
 230         if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
 231                 if (eflag || esrc == NULL || edst == NULL)
 232                         (void)printf("%s ", llcsap_string(llc.dsap));
 233                 else
 234                         (void)printf("%s > %s %s ",
 235                                         etheraddr_string(esrc),
 236                                         etheraddr_string(edst),
 237                                         llcsap_string(llc.dsap));
 238         } else {
 239                 if (eflag || esrc == NULL || edst == NULL)
 240                         (void)printf("%s > %s ",
 241                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 242                                 llcsap_string(llc.dsap));
 243                 else
 244                         (void)printf("%s %s > %s %s ",
 245                                 etheraddr_string(esrc),
 246                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 247                                 etheraddr_string(edst),
 248                                 llcsap_string(llc.dsap));
 249         }
 250
 251         if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
 252                 u_int16_t cmd;
 253                 const char *m;
 254                 char f;
 255
 256                 cmd = LLC_U_CMD(llc.llcu);
 257                 m = tok2str(cmd2str, "%02x", cmd);
 258                 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
 259                         case 0:                 f = 'C'; break;
 260                         case LLC_GSAP:          f = 'R'; break;
 261                         case LLC_U_POLL:        f = 'P'; break;
 262                         case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
 263                         default:                f = '?'; break;
 264                 }
 265
 266                 printf("%s/%c", m, f);
 267
 268                 p += 3;
 269                 length -= 3;
 270                 caplen -= 3;
 271
 272                 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
 273                         if (*p == LLC_XID_FI) {
 274                                 printf(": %02x %02x", p[1], p[2]);
 275                                 p += 3;
 276                                 length -= 3;
 277                                 caplen -= 3;
 278                         }
 279                 }
 280         } else {
 281                 char f;
 282
 283                 /*
 284                  * The control field in I and S frames is little-endian.
 285                  */
 286                 control = EXTRACT_LE_16BITS(&llc.llcu);
 287                 switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
 288                         case 0:                 f = 'C'; break;
 289                         case LLC_GSAP:          f = 'R'; break;
 290                         case LLC_IS_POLL:       f = 'P'; break;
 291                         case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
 292                         default:                f = '?'; break;
 293                 }
 294
 295                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 296                         static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
 297                         (void)printf("%s (r=%d,%c)",
 298                                 llc_s[LLC_S_CMD(control)],
 299                                 LLC_IS_NR(control),
 300                                 f);
 301                 } else {
 302                         (void)printf("I (s=%d,r=%d,%c)",
 303                                 LLC_I_NS(control),
 304                                 LLC_IS_NR(control),
 305                                 f);
 306                 }
 307                 p += 4;
 308                 length -= 4;
 309                 caplen -= 4;
 310         }
 311         (void)printf(" len=%d", length);
 312         return(1);
 313 }
 314
 315 int
 316 snap_print(const u_char *p, u_int length, u_int caplen,
 317     u_short *extracted_ethertype, u_int32_t orgcode, u_short et,
 318     u_int bridge_pad)
 319 {
 320         register int ret;
 321
 322         switch (orgcode) {
 323         case OUI_ENCAP_ETHER:
 324         case OUI_CISCO_90:
 325                 /*
 326                  * This is an encapsulated Ethernet packet,
 327                  * or a packet bridged by some piece of
 328                  * Cisco hardware; the protocol ID is
 329                  * an Ethernet protocol type.
 330                  */
 331                 ret = ether_encap_print(et, p, length, caplen,
 332                     extracted_ethertype);
 333                 if (ret)
 334                         return (ret);
 335                 break;
 336
 337         case OUI_APPLETALK:
 338                 if (et == ETHERTYPE_ATALK) {
 339                         /*
 340                          * No, I have no idea why Apple used one
 341                          * of their own OUIs, rather than
 342                          * 0x000000, and an Ethernet packet
 343                          * type, for Appletalk data packets,
 344                          * but used 0x000000 and an Ethernet
 345                          * packet type for AARP packets.
 346                          */
 347                         ret = ether_encap_print(et, p, length, caplen,
 348                             extracted_ethertype);
 349                         if (ret)
 350                                 return (ret);
 351                 }
 352                 break;
 353
 354         case OUI_CISCO:
 355                 if (et == PID_CISCO_CDP) {
 356                         cdp_print(p, length, caplen);
 357                         return (1);
 358                 }
 359                 break;
 360
 361         case OUI_RFC2684:
 362                 switch (et) {
 363
 364                 case PID_RFC2684_ETH_FCS:
 365                 case PID_RFC2684_ETH_NOFCS:
 366                         /*
 367                          * XXX - remove the last two bytes for
 368                          * PID_RFC2684_ETH_FCS?
 369                          */
 370                         /*
 371                          * Skip the padding.
 372                          */
 373                         caplen -= bridge_pad;
 374                         length -= bridge_pad;
 375                         p += bridge_pad;
 376
 377                         /*
 378                          * What remains is an Ethernet packet.
 379                          */
 380                         ether_print(p, length, caplen);
 381                         return (1);
 382
 383                 case PID_RFC2684_802_5_FCS:
 384                 case PID_RFC2684_802_5_NOFCS:
 385                         /*
 386                          * XXX - remove the last two bytes for
 387                          * PID_RFC2684_ETH_FCS?
 388                          */
 389                         /*
 390                          * Skip the padding, but not the Access
 391                          * Control field.
 392                          */
 393                         caplen -= bridge_pad;
 394                         length -= bridge_pad;
 395                         p += bridge_pad;
 396
 397                         /*
 398                          * What remains is an 802.5 Token Ring
 399                          * packet.
 400                          */
 401                         token_print(p, length, caplen);
 402                         return (1);
 403
 404                 case PID_RFC2684_FDDI_FCS:
 405                 case PID_RFC2684_FDDI_NOFCS:
 406                         /*
 407                          * XXX - remove the last two bytes for
 408                          * PID_RFC2684_ETH_FCS?
 409                          */
 410                         /*
 411                          * Skip the padding.
 412                          */
 413                         caplen -= bridge_pad + 1;
 414                         length -= bridge_pad + 1;
 415                         p += bridge_pad + 1;
 416
 417                         /*
 418                          * What remains is an FDDI packet.
 419                          */
 420                         fddi_print(p, length, caplen);
 421                         return (1);
 422
 423                 case PID_RFC2684_BPDU:
 424                         stp_print(p, length);
 425                         return (1);
 426                 }
 427         }
 428         return (0);
 429 }