packet-llc.c

   1 /* packet-llc.c
   2  * Routines for IEEE 802.2 LLC layer
   3  * Gilbert Ramirez <gram@alumni.rice.edu>
   4  *
   5  * $Id: packet-llc.c,v 1.110 2003/06/10 05:38:51 guy Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <glib.h>
  31 #include <epan/packet.h>
  32 #include "oui.h"
  33 #include "xdlc.h"
  34 #include "etypes.h"
  35 #include "llcsaps.h"
  36 #include "bridged_pids.h"
  37 #include "ppptypes.h"
  38 #include "arcnet_pids.h"
  39 #include "packet-fc.h"
  40 #include "packet-ip.h"
  41 #include "packet-ipx.h"
  42 #include "packet-netbios.h"
  43 #include "packet-vines.h"
  44 #include <epan/sna-utils.h>
  45
  46 #include "packet-llc.h"
  47
  48 #define UDP_PORT_LLC1   12000
  49 #define UDP_PORT_LLC2   12001
  50 #define UDP_PORT_LLC3   12002
  51 #define UDP_PORT_LLC4   12003
  52 #define UDP_PORT_LLC5   12004
  53
  54 static int proto_llc = -1;
  55 static int hf_llc_dsap = -1;
  56 static int hf_llc_ssap = -1;
  57 static int hf_llc_dsap_ig = -1;
  58 static int hf_llc_ssap_cr = -1;
  59 static int hf_llc_ctrl = -1;
  60 static int hf_llc_type = -1;
  61 static int hf_llc_oui = -1;
  62 static int hf_llc_pid = -1;
  63
  64 static gint ett_llc = -1;
  65 static gint ett_llc_ctrl = -1;
  66
  67 static dissector_table_t subdissector_table;
  68 static dissector_table_t cisco_subdissector_table;
  69 static dissector_table_t xid_subdissector_table;
  70
  71 static dissector_handle_t bpdu_handle;
  72 static dissector_handle_t eth_handle;
  73 static dissector_handle_t fddi_handle;
  74 static dissector_handle_t tr_handle;
  75 static dissector_handle_t data_handle;
  76
  77 /*
  78  * Group/Individual bit, in the DSAP.
  79  */
  80 #define DSAP_GI_BIT     0x01
  81
  82 /*
  83  * Command/Response bit, in the SSAP.
  84  *
  85  * The low-order bit of the SSAP apparently determines whether this
  86  * is a request or a response.  (RFC 1390, "Transmission of IP and
  87  * ARP over FDDI Networks", says
  88  *
  89  *      Command frames are identified by having the low order
  90  *      bit of the SSAP address reset to zero.  Response frames
  91  *      have the low order bit of the SSAP address set to one.
  92  *
  93  * and a page I've seen seems to imply that's part of 802.2.)
  94  */
  95 #define SSAP_CR_BIT     0x01
  96
  97 /*
  98  * Mask to extrace the SAP number from the DSAP or the SSAP.
  99  */
 100 #define SAP_MASK        0xFE
 101
 102 /*
 103  * These are for SSAP and DSAP, wth last bit always zero.
 104  * XXX - some DSAPs come in separate "individual" and "group" versions,
 105  * with the last bit 0 and 1, respectively (e.g., LLC Sub-layer Management,
 106  * IBM SNA Path Control, IBM Net Management), but, whilst 0xFE is
 107  * the ISO Network Layer Protocol, 0xFF is the Global LSAP.
 108  */
 109 const value_string sap_vals[] = {
 110         { SAP_NULL,           "NULL LSAP" },
 111         { SAP_LLC_SLMGMT,     "LLC Sub-Layer Management" },
 112         { SAP_SNA_PATHCTRL,   "SNA Path Control" },
 113         { SAP_IP,             "TCP/IP" },
 114         { SAP_SNA1,           "SNA" },
 115         { SAP_SNA2,           "SNA" },
 116         { SAP_PROWAY_NM_INIT, "PROWAY (IEC955) Network Management and Initialization" },
 117         { SAP_NETWARE1,       "NetWare (unofficial?)" },
 118         { SAP_OSINL1,         "ISO Network Layer (OSLAN 1)" },
 119         { SAP_TI,             "Texas Instruments" },
 120         { SAP_OSINL2,         "ISO Network Layer (unofficial?)" },
 121         { SAP_OSINL3,         "ISO Network Layer (unofficial?)" },
 122         { SAP_BPDU,           "Spanning Tree BPDU" },
 123         { SAP_RS511,          "EIA RS-511 Manufacturing Message Service" },
 124         { SAP_OSINL4,         "ISO Network Layer (OSLAN 2)" },
 125         { SAP_X25,            "ISO 8208 (X.25 over 802.2)" },
 126         /*
 127          * XXX - setting the group bit of SAP_X25 make 0x7F; is this just
 128          * a group version of that?
 129          */
 130         { 0x7F,               "ISO 802.2" },
 131         { SAP_XNS,            "XNS" },
 132         { SAP_BACNET,         "BACnet" },
 133         { SAP_NESTAR,         "Nestar" },
 134         { SAP_PROWAY_ASLM,    "PROWAY (IEC955) Active Station List Maintenance" },
 135         { SAP_ARP,            "ARP" },  /* XXX - hand to "dissect_arp()"? */
 136         { SAP_SNAP,           "SNAP" },
 137         { SAP_VINES1,         "Banyan Vines" },
 138         { SAP_VINES2,         "Banyan Vines" },
 139         { SAP_NETWARE2,       "NetWare" },
 140         { SAP_NETBIOS,        "NetBIOS" },
 141         { SAP_IBMNM,          "IBM Net Management" },
 142         { SAP_HPEXT,          "HP Extended LLC" },
 143         { SAP_UB,             "Ungermann-Bass" },
 144         { SAP_RPL,            "Remote Program Load" },
 145         { SAP_OSINL5,         "ISO Network Layer" },
 146         { SAP_GLOBAL,         "Global LSAP" },
 147         { 0x00,               NULL }
 148 };
 149
 150 /*
 151  * See
 152  *
 153  * http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/vlan.htm
 154  *
 155  * for the PIDs for VTP and DRiP that go with an OUI of OUI_CISCO.
 156  */
 157 const value_string oui_vals[] = {
 158         { OUI_ENCAP_ETHER, "Encapsulated Ethernet" },
 159 /*
 160 http://www.cisco.com/univercd/cc/td/doc/product/software/ios113ed/113ed_cr/ibm_r/brprt1/brsrb.htm
 161 */
 162         { OUI_CISCO,       "Cisco" },
 163         { OUI_CISCO_90,    "Cisco IOS 9.0 Compatible" },
 164         { OUI_BRIDGED,     "Frame Relay or ATM bridged frames" },
 165                                 /* RFC 2427, RFC 2684 */
 166         { OUI_ATM_FORUM,   "ATM Forum" },
 167         { OUI_CABLE_BPDU,  "DOCSIS Spanning Tree" }, /* DOCSIS spanning tree BPDU */
 168         { OUI_APPLE_ATALK, "Apple (AppleTalk)" },
 169         { 0,               NULL }
 170 };
 171
 172 void
 173 capture_llc(const guchar *pd, int offset, int len, packet_counts *ld) {
 174
 175         int             is_snap;
 176         guint16         control;
 177         int             llc_header_len;
 178         guint32         oui;
 179         guint16         etype;
 180
 181         if (!BYTES_ARE_IN_FRAME(offset, len, 2)) {
 182                 ld->other++;
 183                 return;
 184         }
 185         is_snap = (pd[offset] == SAP_SNAP) && (pd[offset+1] == SAP_SNAP);
 186         llc_header_len = 2;     /* DSAP + SSAP */
 187
 188         /*
 189          * XXX - the page referred to in the comment above about the
 190          * Command/Response bit also implies that LLC Type 2 always
 191          * uses extended operation, so we don't need to determine
 192          * whether it's basic or extended operation; is that the case?
 193          */
 194         control = get_xdlc_control(pd, offset+2, pd[offset+1] & SSAP_CR_BIT);
 195         llc_header_len += XDLC_CONTROL_LEN(control, TRUE);
 196         if (is_snap)
 197                 llc_header_len += 5;    /* 3 bytes of OUI, 2 bytes of protocol ID */
 198         if (!BYTES_ARE_IN_FRAME(offset, len, llc_header_len)) {
 199                 ld->other++;
 200                 return;
 201         }
 202
 203         if (is_snap) {
 204                 oui = pd[offset+3] << 16 | pd[offset+4] << 8 | pd[offset+5];
 205                 if (XDLC_IS_INFORMATION(control)) {
 206                         etype = pntohs(&pd[offset+6]);
 207                         switch (oui) {
 208
 209                         case OUI_ENCAP_ETHER:
 210                         case OUI_CISCO_90:
 211                         case OUI_APPLE_ATALK:
 212                                 /* No, I have no idea why Apple used
 213                                    one of their own OUIs, rather than
 214                                    OUI_ENCAP_ETHER, and an Ethernet
 215                                    packet type as protocol ID, for
 216                                    AppleTalk data packets - but used
 217                                    OUI_ENCAP_ETHER and an Ethernet
 218                                    packet type for AARP packets. */
 219                                 capture_ethertype(etype, pd, offset+8, len,
 220                                     ld);
 221                                 break;
 222                         case OUI_CISCO:
 223                                 capture_ethertype(etype, pd, offset + 8, len,
 224                                     ld);
 225                                 break;
 226                         default:
 227                                 ld->other++;
 228                                 break;
 229                         }
 230                 }
 231         }
 232         else {
 233                 /* non-SNAP */
 234                 if (XDLC_IS_INFORMATION(control)) {
 235                         switch (pd[offset]) {
 236
 237                         case SAP_IP:
 238                                 capture_ip(pd, offset + llc_header_len, len,
 239                                     ld);
 240                                 break;
 241
 242                         case SAP_NETWARE1:
 243                         case SAP_NETWARE2:
 244                                 capture_ipx(ld);
 245                                 break;
 246
 247                         case SAP_NETBIOS:
 248                                 capture_netbios(ld);
 249                                 break;
 250
 251                         case SAP_VINES1:
 252                         case SAP_VINES2:
 253                                 capture_vines(ld);
 254                                 break;
 255
 256                         default:
 257                                 ld->other++;
 258                                 break;
 259                         }
 260                 }
 261         }
 262 }
 263
 264 static void
 265 dissect_llc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 266 {
 267         proto_tree      *llc_tree = NULL;
 268         proto_item      *ti = NULL;
 269         int             is_snap;
 270         guint16         control;
 271         int             llc_header_len;
 272         guint8          dsap, ssap;
 273         tvbuff_t        *next_tvb;
 274
 275         if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
 276                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "LLC");
 277         }
 278         if (check_col(pinfo->cinfo, COL_INFO)) {
 279                 col_clear(pinfo->cinfo, COL_INFO);
 280         }
 281
 282         dsap = tvb_get_guint8(tvb, 0);
 283         if (tree) {
 284                 ti = proto_tree_add_item(tree, proto_llc, tvb, 0, -1, FALSE);
 285                 llc_tree = proto_item_add_subtree(ti, ett_llc);
 286                 proto_tree_add_uint(llc_tree, hf_llc_dsap, tvb, 0,
 287                         1, dsap & SAP_MASK);
 288                 proto_tree_add_boolean(llc_tree, hf_llc_dsap_ig, tvb, 0,
 289                         1, dsap & DSAP_GI_BIT);
 290         } else
 291                 llc_tree = NULL;
 292
 293         ssap = tvb_get_guint8(tvb, 1);
 294         if (tree) {
 295                 proto_tree_add_uint(llc_tree, hf_llc_ssap, tvb, 1,
 296                         1, ssap & SAP_MASK);
 297                 proto_tree_add_boolean(llc_tree, hf_llc_ssap_cr, tvb, 1,
 298                         1, ssap & SSAP_CR_BIT);
 299         } else
 300                 llc_tree = NULL;
 301
 302         is_snap = (dsap == SAP_SNAP) && (ssap == SAP_SNAP);
 303         llc_header_len = 2;     /* DSAP + SSAP */
 304
 305         /*
 306          * XXX - the page referred to in the comment above about the
 307          * Command/Response bit also implies that LLC Type 2 always
 308          * uses extended operation, so we don't need to determine
 309          * whether it's basic or extended operation; is that the case?
 310          */
 311         control = dissect_xdlc_control(tvb, 2, pinfo, llc_tree,
 312                                 hf_llc_ctrl, ett_llc_ctrl,
 313                                 ssap & SSAP_CR_BIT, TRUE);
 314         llc_header_len += XDLC_CONTROL_LEN(control, TRUE);
 315         if (is_snap)
 316                 llc_header_len += 5;    /* 3 bytes of OUI, 2 bytes of protocol ID */
 317
 318         if (tree)
 319                 proto_item_set_len(ti, llc_header_len);
 320
 321         if (is_snap) {
 322                 dissect_snap(tvb, 3, pinfo, tree, llc_tree, control,
 323                     hf_llc_oui, hf_llc_type, hf_llc_pid, 2);
 324         }
 325         else {
 326                 if (check_col(pinfo->cinfo, COL_INFO)) {
 327                         col_append_fstr(pinfo->cinfo, COL_INFO,
 328                             "; DSAP %s %s, SSAP %s %s",
 329                             val_to_str(dsap & SAP_MASK, sap_vals, "%02x"),
 330                             dsap & DSAP_GI_BIT ?
 331                               "Group" : "Individual",
 332                             val_to_str(ssap & SAP_MASK, sap_vals, "%02x"),
 333                             ssap & SSAP_CR_BIT ?
 334                               "Response" : "Command"
 335                         );
 336                 }
 337
 338                 if (tvb_length_remaining(tvb, llc_header_len) > 0) {
 339                         next_tvb = tvb_new_subset(tvb, llc_header_len, -1, -1);
 340                         if (XDLC_IS_INFORMATION(control)) {
 341                                 /*
 342                                  * Non-SNAP I or UI frame.
 343                                  * Try the regular LLC subdissector table
 344                                  * with the DSAP.
 345                                  */
 346                                 if (!dissector_try_port(subdissector_table,
 347                                     dsap, next_tvb, pinfo, tree)) {
 348                                         call_dissector(data_handle, next_tvb,
 349                                             pinfo, tree);
 350                                 }
 351                         } else if ((control & (XDLC_U_MODIFIER_MASK|XDLC_U))
 352                             == (XDLC_XID|XDLC_U)) {
 353                                 /*
 354                                  * Non-SNAP XID frame.
 355                                  * Try the XID LLC subdissector table
 356                                  * with the DSAP.
 357                                  */
 358                                 if (!dissector_try_port(xid_subdissector_table,
 359                                     dsap, next_tvb, pinfo, tree)) {
 360                                         call_dissector(data_handle, next_tvb,
 361                                             pinfo, tree);
 362                                 }
 363                         } else {
 364                                 call_dissector(data_handle, next_tvb, pinfo,
 365                                     tree);
 366                         }
 367                 }
 368         }
 369 }
 370
 371 /*
 372  * Dissect SNAP header; used elsewhere, e.g. in the Frame Relay dissector.
 373  */
 374 void
 375 dissect_snap(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree,
 376     proto_tree *snap_tree, int control, int hf_oui, int hf_type, int hf_pid,
 377     int bridge_pad)
 378 {
 379         guint32         oui;
 380         guint16         etype;
 381         tvbuff_t        *next_tvb;
 382
 383         oui =   tvb_get_ntoh24(tvb, offset);
 384         etype = tvb_get_ntohs(tvb, offset+3);
 385
 386         if (check_col(pinfo->cinfo, COL_INFO)) {
 387                 col_append_fstr(pinfo->cinfo, COL_INFO,
 388                     "; SNAP, OUI 0x%06X (%s), PID 0x%04X",
 389                     oui, val_to_str(oui, oui_vals, "Unknown"), etype);
 390         }
 391         if (tree) {
 392                 proto_tree_add_uint(snap_tree, hf_oui, tvb, offset, 3, oui);
 393         }
 394
 395         switch (oui) {
 396
 397         case OUI_ENCAP_ETHER:
 398         case OUI_CISCO_90:
 399         case OUI_APPLE_ATALK:
 400                 /* No, I have no idea why Apple used
 401                    one of their own OUIs, rather than
 402                    OUI_ENCAP_ETHER, and an Ethernet
 403                    packet type as protocol ID, for
 404                    AppleTalk data packets - but used
 405                    OUI_ENCAP_ETHER and an Ethernet
 406                    packet type for AARP packets. */
 407                 if (XDLC_IS_INFORMATION(control)) {
 408                         ethertype(etype, tvb, offset+5,
 409                             pinfo, tree, snap_tree, hf_type, -1);
 410                 } else {
 411                         next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 412                         call_dissector(data_handle,next_tvb, pinfo, tree);
 413                 }
 414                 break;
 415
 416         case OUI_BRIDGED:
 417                 /*
 418                  * MAC frames bridged over ATM (RFC 2684) or Frame Relay
 419                  * (RFC 2427).
 420                  *
 421                  * We have to figure out how much padding to put
 422                  * into the frame.  We were handed a "bridge_pad"
 423                  * argument which should be 0 for Frame Relay and
 424                  * 2 for ATM; we add to that the amount of padding
 425                  * common to both bridging types.
 426                  */
 427                 if (tree) {
 428                         proto_tree_add_uint(snap_tree, hf_pid, tvb, offset+3, 2,
 429                             etype);
 430                 }
 431
 432                 switch (etype) {
 433
 434                 case BPID_ETH_WITH_FCS:
 435                 case BPID_ETH_WITHOUT_FCS:
 436                         next_tvb = tvb_new_subset(tvb, offset+5+bridge_pad,
 437                             -1, -1);
 438                         call_dissector(eth_handle, next_tvb, pinfo, tree);
 439                         break;
 440
 441                 case BPID_802_5_WITH_FCS:
 442                 case BPID_802_5_WITHOUT_FCS:
 443                         /*
 444                          * We treat the last padding byte as the Access
 445                          * Control byte, as that's what the Token
 446                          * Ring dissector expects the first byte to
 447                          * be.
 448                          */
 449                         next_tvb = tvb_new_subset(tvb, offset+5+bridge_pad,
 450                             -1, -1);
 451                         call_dissector(tr_handle, next_tvb, pinfo, tree);
 452                         break;
 453
 454                 case BPID_FDDI_WITH_FCS:
 455                 case BPID_FDDI_WITHOUT_FCS:
 456                         next_tvb = tvb_new_subset(tvb, offset+5+1+bridge_pad,
 457                             -1, -1);
 458                         call_dissector(fddi_handle, next_tvb, pinfo, tree);
 459                         break;
 460
 461                 case BPID_BPDU:
 462                         next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 463                         call_dissector(bpdu_handle, next_tvb, pinfo, tree);
 464                         break;
 465
 466                 default:
 467                         next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 468                         call_dissector(data_handle,next_tvb, pinfo, tree);
 469                         break;
 470                 }
 471                 break;
 472
 473         case OUI_CISCO:
 474                 /* So are all CDP packets LLC packets
 475                    with an OUI of OUI_CISCO and a
 476                    protocol ID of 0x2000, or
 477                    are some of them raw or encapsulated
 478                    Ethernet? */
 479                 if (tree) {
 480                         proto_tree_add_uint(snap_tree, hf_pid, tvb, offset+3, 2,
 481                             etype);
 482                 }
 483                 next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 484                 if (XDLC_IS_INFORMATION(control)) {
 485                         /* do lookup with the subdissector table */
 486                         /* for future reference, 0x0102 is Cisco DRIP */
 487                         if (!dissector_try_port(cisco_subdissector_table,
 488                             etype, next_tvb, pinfo, tree))
 489                                 call_dissector(data_handle,next_tvb, pinfo, tree);
 490                 } else
 491                         call_dissector(data_handle,next_tvb, pinfo, tree);
 492                 break;
 493
 494         case OUI_CABLE_BPDU:    /* DOCSIS cable modem spanning tree BPDU */
 495                 if (tree) {
 496                         proto_tree_add_uint(snap_tree, hf_pid, tvb, offset+3, 2,
 497                             etype);
 498                 }
 499                 next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 500                 call_dissector(bpdu_handle, next_tvb, pinfo, tree);
 501                 break;
 502
 503         default:
 504                 if (tree) {
 505                         proto_tree_add_uint(snap_tree, hf_pid, tvb, offset+3, 2,
 506                             etype);
 507                 }
 508                 next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 509                 call_dissector(data_handle,next_tvb, pinfo, tree);
 510                 break;
 511         }
 512 }
 513
 514 void
 515 proto_register_llc(void)
 516 {
 517         static struct true_false_string ig_bit = { "Group", "Individual" };
 518         static struct true_false_string cr_bit = { "Response", "Command" };
 519
 520         static hf_register_info hf[] = {
 521                 { &hf_llc_dsap,
 522                 { "DSAP",       "llc.dsap", FT_UINT8, BASE_HEX,
 523                         VALS(sap_vals), 0x0, "", HFILL }},
 524
 525                 { &hf_llc_dsap_ig,
 526                 { "IG Bit",     "llc.dsap.ig", FT_BOOLEAN, BASE_HEX,
 527                         &ig_bit, 0x0, "Individual/Group", HFILL }},
 528
 529                 { &hf_llc_ssap,
 530                 { "SSAP", "llc.ssap", FT_UINT8, BASE_HEX,
 531                         VALS(sap_vals), 0x0, "", HFILL }},
 532
 533                 { &hf_llc_ssap_cr,
 534                 { "CR Bit", "llc.ssap.cr", FT_BOOLEAN, BASE_HEX,
 535                         &cr_bit, 0x0, "Command/Response", HFILL }},
 536
 537                 { &hf_llc_ctrl,
 538                 { "Control", "llc.control", FT_UINT16, BASE_HEX,
 539                         NULL, 0x0, "", HFILL }},
 540
 541                 /* registered here but handled in ethertype.c */
 542                 { &hf_llc_type,
 543                 { "Type", "llc.type", FT_UINT16, BASE_HEX,
 544                         VALS(etype_vals), 0x0, "", HFILL }},
 545
 546                 { &hf_llc_oui,
 547                 { "Organization Code",  "llc.oui", FT_UINT24, BASE_HEX,
 548                         VALS(oui_vals), 0x0, "", HFILL }},
 549
 550                 { &hf_llc_pid,
 551                 { "Protocol ID", "llc.pid", FT_UINT16, BASE_HEX,
 552                         NULL, 0x0, "", HFILL }}
 553         };
 554         static gint *ett[] = {
 555                 &ett_llc,
 556                 &ett_llc_ctrl,
 557         };
 558
 559         proto_llc = proto_register_protocol("Logical-Link Control", "LLC", "llc");
 560         proto_register_field_array(proto_llc, hf, array_length(hf));
 561         proto_register_subtree_array(ett, array_length(ett));
 562
 563 /* subdissector code */
 564         subdissector_table = register_dissector_table("llc.dsap",
 565           "LLC SAP", FT_UINT8, BASE_HEX);
 566         cisco_subdissector_table = register_dissector_table("llc.cisco_pid",
 567           "Cisco OUI PID", FT_UINT16, BASE_HEX);
 568         xid_subdissector_table = register_dissector_table("llc.xid_dsap",
 569           "LLC XID SAP", FT_UINT8, BASE_HEX);
 570
 571         register_dissector("llc", dissect_llc, proto_llc);
 572 }
 573
 574 void
 575 proto_reg_handoff_llc(void)
 576 {
 577         dissector_handle_t llc_handle;
 578
 579         /*
 580          * Get handles for the BPDU, Ethernet, FDDI, and Token Ring
 581          * dissectors.
 582          */
 583         bpdu_handle = find_dissector("bpdu");
 584         eth_handle = find_dissector("eth");
 585         fddi_handle = find_dissector("fddi");
 586         tr_handle = find_dissector("tr");
 587         data_handle = find_dissector("data");
 588
 589         llc_handle = find_dissector("llc");
 590         dissector_add("wtap_encap", WTAP_ENCAP_ATM_RFC1483, llc_handle);
 591         /* RFC 2043 */
 592         dissector_add("ppp.protocol", PPP_LLC, llc_handle);
 593         /* RFC 2353 */
 594         dissector_add("udp.port", UDP_PORT_LLC1, llc_handle);
 595         dissector_add("udp.port", UDP_PORT_LLC2, llc_handle);
 596         dissector_add("udp.port", UDP_PORT_LLC3, llc_handle);
 597         dissector_add("udp.port", UDP_PORT_LLC4, llc_handle);
 598         dissector_add("udp.port", UDP_PORT_LLC5, llc_handle);
 599         /* IP-over-FC when we have the full FC frame */
 600         dissector_add("fc.ftype", FC_FTYPE_IP, llc_handle);
 601
 602         /*
 603          * BACNET-over-ARCNET is really BACNET-over-802.2 LLC-over-ARCNET,
 604          * apparently.
 605          */
 606         dissector_add("arcnet.protocol_id", ARCNET_PROTO_BACNET, llc_handle);
 607 }