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 1.75 2007-04-13 09:43:11 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 #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_SNA,      "SNA" },
  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         { 0,               NULL },
  64 };
  65
  66 static struct tok llc_cmd_values[] = {
  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 static const struct tok llc_flag_values[] = {
  79         { 0, "Command" },
  80         { LLC_GSAP, "Response" },
  81         { LLC_U_POLL, "Poll" },
  82         { LLC_GSAP|LLC_U_POLL, "Final" },
  83         { LLC_IS_POLL, "Poll" },
  84         { LLC_GSAP|LLC_IS_POLL, "Final" },
  85         { 0, NULL }
  86 };
  87
  88
  89 static const struct tok llc_ig_flag_values[] = {
  90         { 0, "Individual" },
  91         { LLC_IG, "Group" },
  92         { 0, NULL }
  93 };
  94
  95
  96 static const struct tok llc_supervisory_values[] = {
  97         { 0, "Receiver Ready" },
  98         { 1, "Receiver not Ready" },
  99         { 2, "Reject" },
 100         { 0,             NULL }
 101 };
 102
 103
 104 static const struct tok cisco_values[] = {
 105         { PID_CISCO_CDP, "CDP" },
 106         { PID_CISCO_VTP, "VTP" },
 107         { PID_CISCO_DTP, "DTP" },
 108         { PID_CISCO_UDLD, "UDLD" },
 109         { PID_CISCO_PVST, "PVST" },
 110         { PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
 111         { 0,             NULL }
 112 };
 113
 114 static const struct tok bridged_values[] = {
 115         { PID_RFC2684_ETH_FCS,     "Ethernet + FCS" },
 116         { PID_RFC2684_ETH_NOFCS,   "Ethernet w/o FCS" },
 117         { PID_RFC2684_802_4_FCS,   "802.4 + FCS" },
 118         { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
 119         { PID_RFC2684_802_5_FCS,   "Token Ring + FCS" },
 120         { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
 121         { PID_RFC2684_FDDI_FCS,    "FDDI + FCS" },
 122         { PID_RFC2684_FDDI_NOFCS,  "FDDI w/o FCS" },
 123         { PID_RFC2684_802_6_FCS,   "802.6 + FCS" },
 124         { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
 125         { PID_RFC2684_BPDU,        "BPDU" },
 126         { 0,                       NULL },
 127 };
 128
 129 static const struct tok null_values[] = {
 130         { 0,             NULL }
 131 };
 132
 133 struct oui_tok {
 134         u_int32_t       oui;
 135         const struct tok *tok;
 136 };
 137
 138 static const struct oui_tok oui_to_tok[] = {
 139         { OUI_ENCAP_ETHER, ethertype_values },
 140         { OUI_CISCO_90, ethertype_values },     /* uses some Ethertype values */
 141         { OUI_APPLETALK, ethertype_values },    /* uses some Ethertype values */
 142         { OUI_CISCO, cisco_values },
 143         { OUI_RFC2684, bridged_values },        /* bridged, RFC 2427 FR or RFC 2864 ATM */
 144         { 0, NULL }
 145 };
 146
 147 /*
 148  * Returns non-zero IFF it succeeds in printing the header
 149  */
 150 int
 151 llc_print(const u_char *p, u_int length, u_int caplen,
 152           const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
 153 {
 154         u_int8_t dsap_field, dsap, ssap_field, ssap;
 155         u_int16_t control;
 156         int is_u;
 157         register int ret;
 158
 159         *extracted_ethertype = 0;
 160
 161         if (caplen < 3) {
 162                 (void)printf("[|llc]");
 163                 default_print((u_char *)p, caplen);
 164                 return(0);
 165         }
 166
 167         dsap_field = *p;
 168         ssap_field = *(p + 1);
 169
 170         /*
 171          * OK, what type of LLC frame is this?  The length
 172          * of the control field depends on that - I frames
 173          * have a two-byte control field, and U frames have
 174          * a one-byte control field.
 175          */
 176         control = *(p + 2);
 177         if ((control & LLC_U_FMT) == LLC_U_FMT) {
 178                 /*
 179                  * U frame.
 180                  */
 181                 is_u = 1;
 182         } else {
 183                 /*
 184                  * The control field in I and S frames is
 185                  * 2 bytes...
 186                  */
 187                 if (caplen < 4) {
 188                         (void)printf("[|llc]");
 189                         default_print((u_char *)p, caplen);
 190                         return(0);
 191                 }
 192
 193                 /*
 194                  * ...and is little-endian.
 195                  */
 196                 control = EXTRACT_LE_16BITS(p + 2);
 197                 is_u = 0;
 198         }
 199
 200         if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
 201                 /*
 202                  * This is an Ethernet_802.3 IPX frame; it has an
 203                  * 802.3 header (i.e., an Ethernet header where the
 204                  * type/length field is <= ETHERMTU, i.e. it's a length
 205                  * field, not a type field), but has no 802.2 header -
 206                  * the IPX packet starts right after the Ethernet header,
 207                  * with a signature of two bytes of 0xFF (which is
 208                  * LLCSAP_GLOBAL).
 209                  *
 210                  * (It might also have been an Ethernet_802.3 IPX at
 211                  * one time, but got bridged onto another network,
 212                  * such as an 802.11 network; this has appeared in at
 213                  * least one capture file.)
 214                  */
 215
 216             if (eflag)
 217                 printf("IPX 802.3: ");
 218
 219             ipx_print(p, length);
 220             return (1);
 221         }
 222
 223         dsap = dsap_field & ~LLC_IG;
 224         ssap = ssap_field & ~LLC_GSAP;
 225
 226         if (eflag) {
 227                 printf("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
 228                        tok2str(llc_values, "Unknown", dsap),
 229                        dsap,
 230                        tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
 231                        tok2str(llc_values, "Unknown", ssap),
 232                        ssap,
 233                        tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
 234
 235                 if (is_u) {
 236                         printf(", ctrl 0x%02x: ", control);
 237                 } else {
 238                         printf(", ctrl 0x%04x: ", control);
 239                 }
 240         }
 241
 242         if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 243             control == LLC_UI) {
 244                 stp_print(p+3, length-3);
 245                 return (1);
 246         }
 247
 248         if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
 249             control == LLC_UI) {
 250                 ip_print(gndo, p+4, length-4);
 251                 return (1);
 252         }
 253
 254         if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
 255             control == LLC_UI) {
 256                 /*
 257                  * This is an Ethernet_802.2 IPX frame, with an 802.3
 258                  * header and an 802.2 LLC header with the source and
 259                  * destination SAPs being the IPX SAP.
 260                  *
 261                  * Skip DSAP, LSAP, and control field.
 262                  */
 263                 if (eflag)
 264                         printf("IPX 802.2: ");
 265
 266                 ipx_print(p+3, length-3);
 267                 return (1);
 268         }
 269
 270 #ifdef TCPDUMP_DO_SMB
 271         if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
 272             && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
 273                 /*
 274                  * we don't actually have a full netbeui parser yet, but the
 275                  * smb parser can handle many smb-in-netbeui packets, which
 276                  * is very useful, so we call that
 277                  *
 278                  * We don't call it for S frames, however, just I frames
 279                  * (which are frames that don't have the low-order bit,
 280                  * LLC_S_FMT, set in the first byte of the control field)
 281                  * and UI frames (whose control field is just 3, LLC_U_FMT).
 282                  */
 283
 284                 /*
 285                  * Skip the LLC header.
 286                  */
 287                 if (is_u) {
 288                         p += 3;
 289                         length -= 3;
 290                         caplen -= 3;
 291                 } else {
 292                         p += 4;
 293                         length -= 4;
 294                         caplen -= 4;
 295                 }
 296                 netbeui_print(control, p, length);
 297                 return (1);
 298         }
 299 #endif
 300         if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
 301             && control == LLC_UI) {
 302                 isoclns_print(p + 3, length - 3, caplen - 3);
 303                 return (1);
 304         }
 305
 306         if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 307             && control == LLC_UI) {
 308                 /*
 309                  * XXX - what *is* the right bridge pad value here?
 310                  * Does anybody ever bridge one form of LAN traffic
 311                  * over a networking type that uses 802.2 LLC?
 312                  */
 313                 ret = snap_print(p+3, length-3, caplen-3, 2);
 314                 if (ret)
 315                         return (ret);
 316         }
 317
 318         if (!eflag) {
 319                 if (ssap == dsap) {
 320                         if (esrc == NULL || edst == NULL)
 321                                 (void)printf("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 322                         else
 323                                 (void)printf("%s > %s %s ",
 324                                                 etheraddr_string(esrc),
 325                                                 etheraddr_string(edst),
 326                                                 tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 327                 } else {
 328                         if (esrc == NULL || edst == NULL)
 329                                 (void)printf("%s > %s ",
 330                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 331                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 332                         else
 333                                 (void)printf("%s %s > %s %s ",
 334                                         etheraddr_string(esrc),
 335                                         tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
 336                                         etheraddr_string(edst),
 337                                         tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
 338                 }
 339         }
 340
 341         if (is_u) {
 342                 printf("Unnumbered, %s, Flags [%s], length %u",
 343                        tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
 344                        tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
 345                        length);
 346
 347                 p += 3;
 348                 length -= 3;
 349                 caplen -= 3;
 350
 351                 if ((control & ~LLC_U_POLL) == LLC_XID) {
 352                         if (*p == LLC_XID_FI) {
 353                                 printf(": %02x %02x", p[1], p[2]);
 354                                 p += 3;
 355                                 length -= 3;
 356                                 caplen -= 3;
 357                         }
 358                 }
 359         } else {
 360                 if ((control & LLC_S_FMT) == LLC_S_FMT) {
 361                         (void)printf("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
 362                                 tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
 363                                 LLC_IS_NR(control),
 364                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 365                                 length);
 366                 } else {
 367                         (void)printf("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
 368                                 LLC_I_NS(control),
 369                                 LLC_IS_NR(control),
 370                                 tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
 371                                 length);
 372                 }
 373                 p += 4;
 374                 length -= 4;
 375                 caplen -= 4;
 376         }
 377         return(1);
 378 }
 379
 380 int
 381 snap_print(const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
 382 {
 383         u_int32_t orgcode;
 384         register u_short et;
 385         register int ret;
 386
 387         TCHECK2(*p, 5);
 388         orgcode = EXTRACT_24BITS(p);
 389         et = EXTRACT_16BITS(p + 3);
 390
 391         if (eflag) {
 392                 const struct tok *tok = null_values;
 393                 const struct oui_tok *otp;
 394
 395                 for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 396                         if (otp->oui == orgcode) {
 397                                 tok = otp->tok;
 398                                 break;
 399                         }
 400                 }
 401                 (void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
 402                      tok2str(oui_values, "Unknown", orgcode),
 403                      orgcode,
 404                      (orgcode == 0x000000 ? "ethertype" : "pid"),
 405                      tok2str(tok, "Unknown", et),
 406                      et);
 407         }
 408         p += 5;
 409         length -= 5;
 410         caplen -= 5;
 411
 412         switch (orgcode) {
 413         case OUI_ENCAP_ETHER:
 414         case OUI_CISCO_90:
 415                 /*
 416                  * This is an encapsulated Ethernet packet,
 417                  * or a packet bridged by some piece of
 418                  * Cisco hardware; the protocol ID is
 419                  * an Ethernet protocol type.
 420                  */
 421                 ret = ethertype_print(gndo, et, p, length, caplen);
 422                 if (ret)
 423                         return (ret);
 424                 break;
 425
 426         case OUI_APPLETALK:
 427                 if (et == ETHERTYPE_ATALK) {
 428                         /*
 429                          * No, I have no idea why Apple used one
 430                          * of their own OUIs, rather than
 431                          * 0x000000, and an Ethernet packet
 432                          * type, for Appletalk data packets,
 433                          * but used 0x000000 and an Ethernet
 434                          * packet type for AARP packets.
 435                          */
 436                         ret = ethertype_print(gndo, et, p, length, caplen);
 437                         if (ret)
 438                                 return (ret);
 439                 }
 440                 break;
 441
 442         case OUI_CISCO:
 443                 switch (et) {
 444                 case PID_CISCO_CDP:
 445                         cdp_print(p, length, caplen);
 446                         return (1);
 447                 case PID_CISCO_DTP:
 448                         dtp_print(p, length);
 449                         return (1);
 450                 case PID_CISCO_UDLD:
 451                         udld_print(p, length);
 452                         return (1);
 453                 case PID_CISCO_VTP:
 454                         vtp_print(p, length);
 455                         return (1);
 456                 case PID_CISCO_PVST:
 457                 case PID_CISCO_VLANBRIDGE:
 458                         stp_print(p, length);
 459                         return (1);
 460                 default:
 461                         break;
 462                 }
 463
 464         case OUI_RFC2684:
 465                 switch (et) {
 466
 467                 case PID_RFC2684_ETH_FCS:
 468                 case PID_RFC2684_ETH_NOFCS:
 469                         /*
 470                          * XXX - remove the last two bytes for
 471                          * PID_RFC2684_ETH_FCS?
 472                          */
 473                         /*
 474                          * Skip the padding.
 475                          */
 476                         TCHECK2(*p, bridge_pad);
 477                         caplen -= bridge_pad;
 478                         length -= bridge_pad;
 479                         p += bridge_pad;
 480
 481                         /*
 482                          * What remains is an Ethernet packet.
 483                          */
 484                         ether_print(gndo, p, length, caplen, NULL, NULL);
 485                         return (1);
 486
 487                 case PID_RFC2684_802_5_FCS:
 488                 case PID_RFC2684_802_5_NOFCS:
 489                         /*
 490                          * XXX - remove the last two bytes for
 491                          * PID_RFC2684_ETH_FCS?
 492                          */
 493                         /*
 494                          * Skip the padding, but not the Access
 495                          * Control field.
 496                          */
 497                         TCHECK2(*p, bridge_pad);
 498                         caplen -= bridge_pad;
 499                         length -= bridge_pad;
 500                         p += bridge_pad;
 501
 502                         /*
 503                          * What remains is an 802.5 Token Ring
 504                          * packet.
 505                          */
 506                         token_print(p, length, caplen);
 507                         return (1);
 508
 509                 case PID_RFC2684_FDDI_FCS:
 510                 case PID_RFC2684_FDDI_NOFCS:
 511                         /*
 512                          * XXX - remove the last two bytes for
 513                          * PID_RFC2684_ETH_FCS?
 514                          */
 515                         /*
 516                          * Skip the padding.
 517                          */
 518                         TCHECK2(*p, bridge_pad + 1);
 519                         caplen -= bridge_pad + 1;
 520                         length -= bridge_pad + 1;
 521                         p += bridge_pad + 1;
 522
 523                         /*
 524                          * What remains is an FDDI packet.
 525                          */
 526                         fddi_print(p, length, caplen);
 527                         return (1);
 528
 529                 case PID_RFC2684_BPDU:
 530                         stp_print(p, length);
 531                         return (1);
 532                 }
 533         }
 534         return (0);
 535
 536 trunc:
 537         (void)printf("[|snap]");
 538         return (1);
 539 }
 540
 541
 542 /*
 543  * Local Variables:
 544  * c-style: whitesmith
 545  * c-basic-offset: 8
 546  * End:
 547  */