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 1.61 2005/04/06 21:32:41 mcr 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 #include "oui.h"
  48
  49 static struct tok llc_values[] = {
  50         { LLCSAP_NULL,     "Null" },
  51         { LLCSAP_GLOBAL,   "Global" },
  52         { LLCSAP_8021B_I,  "802.1B I" },
  53         { LLCSAP_8021B_G,  "802.1B G" },
  54         { LLCSAP_IP,       "IP" },
  55         { LLCSAP_PROWAYNM, "ProWay NM" },
  56         { LLCSAP_8021D,    "STP" },
  57         { LLCSAP_RS511,    "RS511" },
  58         { LLCSAP_ISO8208,  "ISO8208" },
  59         { LLCSAP_PROWAY,   "ProWay" },
  60         { LLCSAP_SNAP,     "SNAP" },
  61         { LLCSAP_IPX,      "IPX" },
  62         { LLCSAP_NETBEUI,  "NetBeui" },
  63         { LLCSAP_ISONS,    "OSI" },
  64 };
  65
  66 static struct tok cmd2str[] = {
  67         { LLC_UI,       "ui" },
  68         { LLC_TEST,     "test" },
  69         { LLC_XID,      "xid" },
  70         { LLC_UA,       "ua" },
  71         { LLC_DISC,     "disc" },
  72         { LLC_DM,       "dm" },
  73         { LLC_SABME,    "sabme" },
  74         { LLC_FRMR,     "frmr" },
  75         { 0,            NULL }
  76 };
  77
  78 /*
  79  * Returns non-zero IFF it succeeds in printing the header
  80  */
  81 int
  82 llc_print(const u_char *p, u_int length, u_int caplen,
  83           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
  84 {
  85         struct llc llc;
  86         register u_short et;
  87         u_int16_t control;
  88         register int ret;
  89
  90         if (caplen < 3) {
  91                 (void)printf("[|llc]");
  92                 default_print((u_char *)p, caplen);
  93                 return(0);
  94         }
  95
  96         /* Watch out for possible alignment problems */
  97         memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
  98
  99         if (eflag)
 100           printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x: ",
 101                  tok2str(llc_values,"Unknown",llc.dsap),
 102                  llc.dsap,
 103                  tok2str(llc_values,"Unknown",llc.ssap),
 104                  llc.ssap,
 105                  llc.llcu);
 106
 107         if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
 108                 /*
 109                  * This is an Ethernet_802.3 IPX frame; it has an
 110                  * 802.3 header (i.e., an Ethernet header where the
 111                  * type/length field is <= ETHERMTU, i.e. it's a length
 112                  * field, not a type field), but has no 802.2 header -
 113                  * the IPX packet starts right after the Ethernet header,
 114                  * with a signature of two bytes of 0xFF (which is
 115                  * LLCSAP_GLOBAL).
 116                  *
 117                  * (It might also have been an Ethernet_802.3 IPX at
 118                  * one time, but got bridged onto another network,
 119                  * such as an 802.11 network; this has appeared in at
 120                  * least one capture file.)
 121                  */
 122
 123             if (eflag)
 124                 printf("IPX-802.3: ");
 125
 126             ipx_print(p, length);
 127             return (1);
 128         }
 129
 130         if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
 131                 stp_print(p, length);
 132                 return (1);
 133         }
 134
 135         if (llc.ssap == LLCSAP_IP && llc.dsap == LLCSAP_IP) {
 136                 ip_print(gndo, p+4, length-4);
 137                 return (1);
 138         }
 139
 140         if (llc.ssap == LLCSAP_IPX && llc.dsap == LLCSAP_IPX &&
 141             llc.llcui == LLC_UI) {
 142                 /*
 143                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 144                  * header and an 802.2 LLC header with the source and
 145                  * destination SAPs being the IPX SAP.
 146                  *
 147                  * Skip DSAP, LSAP, and control field.
 148                  */
 149                 printf("(NOV-802.2) ");
 150                 p += 3;
 151                 length -= 3;
 152                 caplen -= 3;
 153                 ipx_print(p, length);
 154                 return (1);
 155         }
 156
 157 #ifdef TCPDUMP_DO_SMB
 158         if (llc.ssap == LLCSAP_NETBEUI && llc.dsap == LLCSAP_NETBEUI
 159             && (!(llc.llcu & LLC_S_FMT) || llc.llcu == LLC_U_FMT)) {
 160                 /*
 161                  * we don't actually have a full netbeui parser yet, but the
 162                  * smb parser can handle many smb-in-netbeui packets, which
 163                  * is very useful, so we call that
 164                  *
 165                  * We don't call it for S frames, however, just I frames
 166                  * (which are frames that don't have the low-order bit,
 167                  * LLC_S_FMT, set in the first byte of the control field)
 168                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 169                  */
 170
 171                 /*
 172                  * Skip the DSAP and LSAP.
 173                  */
 174                 p += 2;
 175                 length -= 2;
 176                 caplen -= 2;
 177
 178                 /*
 179                  * OK, what type of LLC frame is this?  The length
 180                  * of the control field depends on that - I frames
 181                  * have a two-byte control field, and U frames have
 182                  * a one-byte control field.
 183                  */
 184                 if (llc.llcu == LLC_U_FMT) {
 185                         control = llc.llcu;
 186                         p += 1;
 187                         length -= 1;
 188                         caplen -= 1;
 189                 } else {
 190                         /*
 191                          * The control field in I and S frames is
 192                          * little-endian.
 193                          */
 194                         control = EXTRACT_LE_16BITS(&llc.llcu);
 195                         p += 2;
 196                         length -= 2;
 197                         caplen -= 2;
 198                 }
 199                 netbeui_print(control, p, length);
 200                 return (1);
 201         }
 202 #endif
 203         if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
 204             && llc.llcui == LLC_UI) {
 205                 isoclns_print(p + 3, length - 3, caplen - 3);
 206                 return (1);
 207         }
 208
 209         if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
 210             && llc.llcui == LLC_UI) {
 211                 u_int32_t orgcode;
 212
 213                 if (caplen < sizeof(llc)) {
 214                         (void)printf("[|llc-snap]");
 215                         default_print((u_char *)p, caplen);
 216                         return (0);
 217                 }
 218
 219                 caplen -= sizeof(llc);
 220                 length -= sizeof(llc);
 221                 p += sizeof(llc);
 222
 223                 orgcode = EXTRACT_24BITS(&llc.llc_orgcode[0]);
 224                 et = EXTRACT_16BITS(&llc.llc_ethertype[0]);
 225
 226                 if (eflag)
 227                     (void)printf("oui %s (0x%06x), ethertype %s (0x%04x): ",
 228                                  tok2str(oui_values,"Unknown",orgcode),
 229                                  orgcode,
 230                                  tok2str(ethertype_values,"Unknown", et),
 231                                  et);
 232
 233                 /*
 234                  * XXX - what *is* the right bridge pad value here?
 235                  * Does anybody ever bridge one form of LAN traffic
 236                  * over a networking type that uses 802.2 LLC?
 237                  */
 238                 ret = snap_print(p, length, caplen, extracted_ethertype,
 239                     orgcode, et, 2);
 240                 if (ret)
 241                         return (ret);
 242         }
 243
 244         if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
 245                 if (eflag || esrc == NULL || edst == NULL)
 246                         (void)printf("%s ", llcsap_string(llc.dsap));
 247                 else
 248                         (void)printf("%s > %s %s ",
 249                                         etheraddr_string(esrc),
 250                                         etheraddr_string(edst),
 251                                         llcsap_string(llc.dsap));
 252         } else {
 253                 if (eflag || esrc == NULL || edst == NULL)
 254                         (void)printf("%s > %s ",
 255                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 256                                 llcsap_string(llc.dsap));
 257                 else
 258                         (void)printf("%s %s > %s %s ",
 259                                 etheraddr_string(esrc),
 260                                 llcsap_string(llc.ssap & ~LLC_GSAP),
 261                                 etheraddr_string(edst),
 262                                 llcsap_string(llc.dsap));
 263         }
 264
 265         if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
 266                 u_int16_t cmd;
 267                 const char *m;
 268                 char f;
 269
 270                 cmd = LLC_U_CMD(llc.llcu);
 271                 m = tok2str(cmd2str, "%02x", cmd);
 272                 switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
 273                         case 0:                 f = 'C'; break;
 274                         case LLC_GSAP:          f = 'R'; break;
 275                         case LLC_U_POLL:        f = 'P'; break;
 276                         case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
 277                         default:                f = '?'; break;
 278                 }
 279
 280                 printf("%s/%c", m, f);
 281
 282                 p += 3;
 283                 length -= 3;
 284                 caplen -= 3;
 285
 286                 if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
 287                         if (*p == LLC_XID_FI) {
 288                                 printf(": %02x %02x", p[1], p[2]);
 289                                 p += 3;
 290                                 length -= 3;
 291                                 caplen -= 3;
 292                         }
 293                 }
 294         } else {
 295                 char f;
 296
 297                 /*
 298                  * The control field in I and S frames is little-endian.
 299                  */
 300                 control = EXTRACT_LE_16BITS(&llc.llcu);
 301                 switch ((llc.ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
 302                         case 0:                 f = 'C'; break;
 303                         case LLC_GSAP:          f = 'R'; break;
 304                         case LLC_IS_POLL:       f = 'P'; break;
 305                         case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
 306                         default:                f = '?'; break;
 307                 }
 308
 309                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 310                         static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
 311                         (void)printf("%s (r=%d,%c)",
 312                                 llc_s[LLC_S_CMD(control)],
 313                                 LLC_IS_NR(control),
 314                                 f);
 315                 } else {
 316                         (void)printf("I (s=%d,r=%d,%c)",
 317                                 LLC_I_NS(control),
 318                                 LLC_IS_NR(control),
 319                                 f);
 320                 }
 321                 p += 4;
 322                 length -= 4;
 323                 caplen -= 4;
 324         }
 325         return(1);
 326 }
 327
 328 int
 329 snap_print(const u_char *p, u_int length, u_int caplen,
 330     u_short *extracted_ethertype, u_int32_t orgcode, u_short et,
 331     u_int bridge_pad)
 332 {
 333         register int ret;
 334
 335         switch (orgcode) {
 336         case OUI_ENCAP_ETHER:
 337         case OUI_CISCO_90:
 338                 /*
 339                  * This is an encapsulated Ethernet packet,
 340                  * or a packet bridged by some piece of
 341                  * Cisco hardware; the protocol ID is
 342                  * an Ethernet protocol type.
 343                  */
 344                 ret = ether_encap_print(et, p, length, caplen,
 345                     extracted_ethertype);
 346                 if (ret)
 347                         return (ret);
 348                 break;
 349
 350         case OUI_APPLETALK:
 351                 if (et == ETHERTYPE_ATALK) {
 352                         /*
 353                          * No, I have no idea why Apple used one
 354                          * of their own OUIs, rather than
 355                          * 0x000000, and an Ethernet packet
 356                          * type, for Appletalk data packets,
 357                          * but used 0x000000 and an Ethernet
 358                          * packet type for AARP packets.
 359                          */
 360                         ret = ether_encap_print(et, p, length, caplen,
 361                             extracted_ethertype);
 362                         if (ret)
 363                                 return (ret);
 364                 }
 365                 break;
 366
 367         case OUI_CISCO:
 368                 if (et == PID_CISCO_CDP) {
 369                         cdp_print(p, length, caplen);
 370                         return (1);
 371                 }
 372                 break;
 373
 374         case OUI_RFC2684:
 375                 switch (et) {
 376
 377                 case PID_RFC2684_ETH_FCS:
 378                 case PID_RFC2684_ETH_NOFCS:
 379                         /*
 380                          * XXX - remove the last two bytes for
 381                          * PID_RFC2684_ETH_FCS?
 382                          */
 383                         /*
 384                          * Skip the padding.
 385                          */
 386                         caplen -= bridge_pad;
 387                         length -= bridge_pad;
 388                         p += bridge_pad;
 389
 390                         /*
 391                          * What remains is an Ethernet packet.
 392                          */
 393                         ether_print(p, length, caplen);
 394                         return (1);
 395
 396                 case PID_RFC2684_802_5_FCS:
 397                 case PID_RFC2684_802_5_NOFCS:
 398                         /*
 399                          * XXX - remove the last two bytes for
 400                          * PID_RFC2684_ETH_FCS?
 401                          */
 402                         /*
 403                          * Skip the padding, but not the Access
 404                          * Control field.
 405                          */
 406                         caplen -= bridge_pad;
 407                         length -= bridge_pad;
 408                         p += bridge_pad;
 409
 410                         /*
 411                          * What remains is an 802.5 Token Ring
 412                          * packet.
 413                          */
 414                         token_print(p, length, caplen);
 415                         return (1);
 416
 417                 case PID_RFC2684_FDDI_FCS:
 418                 case PID_RFC2684_FDDI_NOFCS:
 419                         /*
 420                          * XXX - remove the last two bytes for
 421                          * PID_RFC2684_ETH_FCS?
 422                          */
 423                         /*
 424                          * Skip the padding.
 425                          */
 426                         caplen -= bridge_pad + 1;
 427                         length -= bridge_pad + 1;
 428                         p += bridge_pad + 1;
 429
 430                         /*
 431                          * What remains is an FDDI packet.
 432                          */
 433                         fddi_print(p, length, caplen);
 434                         return (1);
 435
 436                 case PID_RFC2684_BPDU:
 437                         stp_print(p, length);
 438                         return (1);
 439                 }
 440         }
 441         return (0);
 442 }
 443
 444
 445 /*
 446  * Local Variables:
 447  * c-style: whitesmith
 448  * c-basic-offset: 8
 449  * End:
 450  */