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 #define NETDISSECT_REWORKED
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <tcpdump-stdinc.h>
  33
  34 #include "interface.h"
  35 #include "addrtoname.h"
  36 #include "extract.h"                    /* must come after interface.h */
  37
  38 #include "llc.h"
  39 #include "ethertype.h"
  40 #include "oui.h"
  41
  42 static const struct tok llc_values[] = {
  43         { LLCSAP_NULL,     "Null" },
  44         { LLCSAP_GLOBAL,   "Global" },
  45         { LLCSAP_8021B_I,  "802.1B I" },
  46         { LLCSAP_8021B_G,  "802.1B G" },
  47         { LLCSAP_IP,       "IP" },
  48         { LLCSAP_SNA,      "SNA" },
  49         { LLCSAP_PROWAYNM, "ProWay NM" },
  50         { LLCSAP_8021D,    "STP" },
  51         { LLCSAP_RS511,    "RS511" },
  52         { LLCSAP_ISO8208,  "ISO8208" },
  53         { LLCSAP_PROWAY,   "ProWay" },
  54         { LLCSAP_SNAP,     "SNAP" },
  55         { LLCSAP_IPX,      "IPX" },
  56         { LLCSAP_NETBEUI,  "NetBeui" },
  57         { LLCSAP_ISONS,    "OSI" },
  58         { 0,               NULL },
  59 };
  60
  61 static const struct tok llc_cmd_values[] = {
  62         { LLC_UI,       "ui" },
  63         { LLC_TEST,     "test" },
  64         { LLC_XID,      "xid" },
  65         { LLC_UA,       "ua" },
  66         { LLC_DISC,     "disc" },
  67         { LLC_DM,       "dm" },
  68         { LLC_SABME,    "sabme" },
  69         { LLC_FRMR,     "frmr" },
  70         { 0,            NULL }
  71 };
  72
  73 static const struct tok llc_flag_values[] = {
  74         { 0, "Command" },
  75         { LLC_GSAP, "Response" },
  76         { LLC_U_POLL, "Poll" },
  77         { LLC_GSAP|LLC_U_POLL, "Final" },
  78         { LLC_IS_POLL, "Poll" },
  79         { LLC_GSAP|LLC_IS_POLL, "Final" },
  80         { 0, NULL }
  81 };
  82
  83
  84 static const struct tok llc_ig_flag_values[] = {
  85         { 0, "Individual" },
  86         { LLC_IG, "Group" },
  87         { 0, NULL }
  88 };
  89
  90
  91 static const struct tok llc_supervisory_values[] = {
  92         { 0, "Receiver Ready" },
  93         { 1, "Receiver not Ready" },
  94         { 2, "Reject" },
  95         { 0,             NULL }
  96 };
  97
  98
  99 static const struct tok cisco_values[] = {
 100         { PID_CISCO_CDP, "CDP" },
 101         { PID_CISCO_VTP, "VTP" },
 102         { PID_CISCO_DTP, "DTP" },
 103         { PID_CISCO_UDLD, "UDLD" },
 104         { PID_CISCO_PVST, "PVST" },
 105         { PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
 106         { 0,             NULL }
 107 };
 108
 109 static const struct tok bridged_values[] = {
 110         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 111         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 112         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 113         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 114         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 115         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 116         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 117         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 118         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 119         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 120         { PID_RFC2684_BPDU,        "BPDU" },
 121         { 0,                       NULL },
 122 };
 123
 124 static const struct tok null_values[] = {
 125         { 0,             NULL }
 126 };
 127
 128 struct oui_tok {
 129         uint32_t        oui;
 130         const struct tok *tok;
 131 };
 132
 133 static const struct oui_tok oui_to_tok[] = {
 134         { OUI_ENCAP_ETHER, ethertype_values },
 135         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 136         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 137         { OUI_CISCO, cisco_values },
 138         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 139         { 0, NULL }
 140 };
 141
 142 /*
 143  * Returns non-zero IFF it succeeds in printing the header
 144  */
 145 int
 146 llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 147           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 148 {
 149         uint8_t dsap_field, dsap, ssap_field, ssap;
 150         uint16_t control;
 151         int is_u;
 152         register int ret;
 153
 154         *extracted_ethertype = 0;
 155
 156         if (caplen < 3) {
 157                 ND_PRINT((ndo, "[|llc]"));
 158                 ND_DEFAULTPRINT((u_char *)p, caplen);
 159                 return(0);
 160         }
 161
 162         dsap_field = *p;
 163         ssap_field = *(p + 1);
 164
 165         /*
 166          * OK, what type of LLC frame is this?  The length
 167          * of the control field depends on that - I frames
 168          * have a two-byte control field, and U frames have
 169          * a one-byte control field.
 170          */
 171         control = *(p + 2);
 172         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 173                 /*
 174                  * U frame.
 175                  */
 176                 is_u = 1;
 177         } else {
 178                 /*
 179                  * The control field in I and S frames is
 180                  * 2 bytes...
 181                  */
 182                 if (caplen < 4) {
 183                         ND_PRINT((ndo, "[|llc]"));
 184                         ND_DEFAULTPRINT((u_char *)p, caplen);
 185                         return(0);
 186                 }
 187
 188                 /*
 189                  * ...and is little-endian.
 190                  */
 191                 control = EXTRACT_LE_16BITS(p + 2);
 192                 is_u = 0;
 193         }
 194
 195         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 196                 /*
 197                  * This is an Ethernet_802.3 IPX frame; it has an
 198                  * 802.3 header (i.e., an Ethernet header where the
 199                  * type/length field is <= ETHERMTU, i.e. it's a length
 200                  * field, not a type field), but has no 802.2 header -
 201                  * the IPX packet starts right after the Ethernet header,
 202                  * with a signature of two bytes of 0xFF (which is
 203                  * LLCSAP_GLOBAL).
 204                  *
 205                  * (It might also have been an Ethernet_802.3 IPX at
 206                  * one time, but got bridged onto another network,
 207                  * such as an 802.11 network; this has appeared in at
 208                  * least one capture file.)
 209                  */
 210
 211             if (ndo->ndo_eflag)
 212                 ND_PRINT((ndo, "IPX 802.3: "));
 213
 214             ipx_print(ndo, p, length);
 215             return (1);
 216         }
 217
 218         dsap = dsap_field & ~LLC_IG;
 219         ssap = ssap_field & ~LLC_GSAP;
 220
 221         if (ndo->ndo_eflag) {
 222                 ND_PRINT((ndo, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 223                        tok2str(llc_values, "Unknown", dsap),
 224                        dsap,
 225                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 226                        tok2str(llc_values, "Unknown", ssap),
 227                        ssap,
 228                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP)));
 229
 230                 if (is_u) {
 231                         ND_PRINT((ndo, ", ctrl 0x%02x: ", control));
 232                 } else {
 233                         ND_PRINT((ndo, ", ctrl 0x%04x: ", control));
 234                 }
 235         }
 236
 237         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 238             control == LLC_UI) {
 239                 stp_print(ndo, p+3, length-3);
 240                 return (1);
 241         }
 242
 243         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 244             control == LLC_UI) {
 245                 ip_print(ndo, p+4, length-4);
 246                 return (1);
 247         }
 248
 249         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 250             control == LLC_UI) {
 251                 /*
 252                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 253                  * header and an 802.2 LLC header with the source and
 254                  * destination SAPs being the IPX SAP.
 255                  *
 256                  * Skip DSAP, LSAP, and control field.
 257                  */
 258                 if (ndo->ndo_eflag)
 259                         ND_PRINT((ndo, "IPX 802.2: "));
 260
 261                 ipx_print(ndo, p+3, length-3);
 262                 return (1);
 263         }
 264
 265 #ifdef TCPDUMP_DO_SMB
 266         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 267             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 268                 /*
 269                  * we don't actually have a full netbeui parser yet, but the
 270                  * smb parser can handle many smb-in-netbeui packets, which
 271                  * is very useful, so we call that
 272                  *
 273                  * We don't call it for S frames, however, just I frames
 274                  * (which are frames that don't have the low-order bit,
 275                  * LLC_S_FMT, set in the first byte of the control field)
 276                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 277                  */
 278
 279                 /*
 280                  * Skip the LLC header.
 281                  */
 282                 if (is_u) {
 283                         p += 3;
 284                         length -= 3;
 285                 } else {
 286                         p += 4;
 287                         length -= 4;
 288                 }
 289                 netbeui_print(ndo, control, p, length);
 290                 return (1);
 291         }
 292 #endif
 293         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 294             && control == LLC_UI) {
 295                 isoclns_print(ndo, p + 3, length - 3, caplen - 3);
 296                 return (1);
 297         }
 298
 299         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 300             && control == LLC_UI) {
 301                 /*
 302                  * XXX - what *is* the right bridge pad value here?
 303                  * Does anybody ever bridge one form of LAN traffic
 304                  * over a networking type that uses 802.2 LLC?
 305                  */
 306                 ret = snap_print(ndo, p+3, length-3, caplen-3, 2);
 307                 if (ret)
 308                         return (ret);
 309         }
 310
 311         if (!ndo->ndo_eflag) {
 312                 if (ssap == dsap) {
 313                         if (esrc == NULL || edst == NULL)
 314                                 ND_PRINT((ndo, "%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 315                         else
 316                                 ND_PRINT((ndo, "%s > %s %s ",
 317                                                 etheraddr_string(ndo, esrc),
 318                                                 etheraddr_string(ndo, edst),
 319                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 320                 } else {
 321                         if (esrc == NULL || edst == NULL)
 322                                 ND_PRINT((ndo, "%s > %s ",
 323                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 324                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 325                         else
 326                                 ND_PRINT((ndo, "%s %s > %s %s ",
 327                                         etheraddr_string(ndo, esrc),
 328                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 329                                         etheraddr_string(ndo, edst),
 330                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap)));
 331                 }
 332         }
 333
 334         if (is_u) {
 335                 ND_PRINT((ndo, "Unnumbered, %s, Flags [%s], length %u",
 336                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 337                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 338                        length));
 339
 340                 p += 3;
 341
 342                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 343                         if (*p == LLC_XID_FI) {
 344                                 ND_PRINT((ndo, ": %02x %02x", p[1], p[2]));
 345                         }
 346                 }
 347         } else {
 348                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 349                         ND_PRINT((ndo, "Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 350                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 351                                 LLC_IS_NR(control),
 352                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 353                                 length));
 354                 } else {
 355                         ND_PRINT((ndo, "Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 356                                 LLC_I_NS(control),
 357                                 LLC_IS_NR(control),
 358                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 359                                 length));
 360                 }
 361         }
 362         return(1);
 363 }
 364
 365 int
 366 snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
 367 {
 368         uint32_t orgcode;
 369         register u_short et;
 370         register int ret;
 371
 372         ND_TCHECK2(*p, 5);
 373         orgcode = EXTRACT_24BITS(p);
 374         et = EXTRACT_16BITS(p + 3);
 375
 376         if (ndo->ndo_eflag) {
 377                 const struct tok *tok = null_values;
 378                 const struct oui_tok *otp;
 379
 380                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 381                         if (otp->oui == orgcode) {
 382                                 tok = otp->tok;
 383                                 break;
 384                         }
 385                 }
 386                 ND_PRINT((ndo, "oui %s (0x%06x), %s %s (0x%04x): ",
 387                      tok2str(oui_values, "Unknown", orgcode),
 388                      orgcode,
 389                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 390                      tok2str(tok, "Unknown", et),
 391                      et));
 392         }
 393         p += 5;
 394         length -= 5;
 395         caplen -= 5;
 396
 397         switch (orgcode) {
 398         case OUI_ENCAP_ETHER:
 399         case OUI_CISCO_90:
 400                 /*
 401                  * This is an encapsulated Ethernet packet,
 402                  * or a packet bridged by some piece of
 403                  * Cisco hardware; the protocol ID is
 404                  * an Ethernet protocol type.
 405                  */
 406                 ret = ethertype_print(ndo, et, p, length, caplen);
 407                 if (ret)
 408                         return (ret);
 409                 break;
 410
 411         case OUI_APPLETALK:
 412                 if (et == ETHERTYPE_ATALK) {
 413                         /*
 414                          * No, I have no idea why Apple used one
 415                          * of their own OUIs, rather than
 416                          * 0x000000, and an Ethernet packet
 417                          * type, for Appletalk data packets,
 418                          * but used 0x000000 and an Ethernet
 419                          * packet type for AARP packets.
 420                          */
 421                         ret = ethertype_print(ndo, et, p, length, caplen);
 422                         if (ret)
 423                                 return (ret);
 424                 }
 425                 break;
 426
 427         case OUI_CISCO:
 428                 switch (et) {
 429                 case PID_CISCO_CDP:
 430                         cdp_print(ndo, p, length, caplen);
 431                         return (1);
 432                 case PID_CISCO_DTP:
 433                         dtp_print(ndo, p, length);
 434                         return (1);
 435                 case PID_CISCO_UDLD:
 436                         udld_print(ndo, p, length);
 437                         return (1);
 438                 case PID_CISCO_VTP:
 439                         vtp_print(ndo, p, length);
 440                         return (1);
 441                 case PID_CISCO_PVST:
 442                 case PID_CISCO_VLANBRIDGE:
 443                         stp_print(ndo, p, length);
 444                         return (1);
 445                 default:
 446                         break;
 447                 }
 448                 break;
 449
 450         case OUI_RFC2684:
 451                 switch (et) {
 452
 453                 case PID_RFC2684_ETH_FCS:
 454                 case PID_RFC2684_ETH_NOFCS:
 455                         /*
 456                          * XXX - remove the last two bytes for
 457                          * PID_RFC2684_ETH_FCS?
 458                          */
 459                         /*
 460                          * Skip the padding.
 461                          */
 462                         ND_TCHECK2(*p, bridge_pad);
 463                         caplen -= bridge_pad;
 464                         length -= bridge_pad;
 465                         p += bridge_pad;
 466
 467                         /*
 468                          * What remains is an Ethernet packet.
 469                          */
 470                         ether_print(ndo, p, length, caplen, NULL, NULL);
 471                         return (1);
 472
 473                 case PID_RFC2684_802_5_FCS:
 474                 case PID_RFC2684_802_5_NOFCS:
 475                         /*
 476                          * XXX - remove the last two bytes for
 477                          * PID_RFC2684_ETH_FCS?
 478                          */
 479                         /*
 480                          * Skip the padding, but not the Access
 481                          * Control field.
 482                          */
 483                         ND_TCHECK2(*p, bridge_pad);
 484                         caplen -= bridge_pad;
 485                         length -= bridge_pad;
 486                         p += bridge_pad;
 487
 488                         /*
 489                          * What remains is an 802.5 Token Ring
 490                          * packet.
 491                          */
 492                         token_print(ndo, p, length, caplen);
 493                         return (1);
 494
 495                 case PID_RFC2684_FDDI_FCS:
 496                 case PID_RFC2684_FDDI_NOFCS:
 497                         /*
 498                          * XXX - remove the last two bytes for
 499                          * PID_RFC2684_ETH_FCS?
 500                          */
 501                         /*
 502                          * Skip the padding.
 503                          */
 504                         ND_TCHECK2(*p, bridge_pad + 1);
 505                         caplen -= bridge_pad + 1;
 506                         length -= bridge_pad + 1;
 507                         p += bridge_pad + 1;
 508
 509                         /*
 510                          * What remains is an FDDI packet.
 511                          */
 512                         fddi_print(ndo, p, length, caplen);
 513                         return (1);
 514
 515                 case PID_RFC2684_BPDU:
 516                         stp_print(ndo, p, length);
 517                         return (1);
 518                 }
 519         }
 520         return (0);
 521
 522 trunc:
 523         ND_PRINT((ndo, "[|snap]"));
 524         return (1);
 525 }
 526
 527
 528 /*
 529  * Local Variables:
 530  * c-style: whitesmith
 531  * c-basic-offset: 8
 532  * End:
 533  */