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 1.118 2004/01/18 08:32:45 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_n_r = -1;
  61 static int hf_llc_n_s = -1;
  62 static int hf_llc_p = -1;
  63 static int hf_llc_p_ext = -1;
  64 static int hf_llc_f = -1;
  65 static int hf_llc_f_ext = -1;
  66 static int hf_llc_s_ftype = -1;
  67 static int hf_llc_u_modifier_cmd = -1;
  68 static int hf_llc_u_modifier_resp = -1;
  69 static int hf_llc_ftype_i = -1;
  70 static int hf_llc_ftype_s_u = -1;
  71 static int hf_llc_ftype_s_u_ext = -1;
  72 static int hf_llc_type = -1;
  73 static int hf_llc_oui = -1;
  74 static int hf_llc_pid = -1;
  75
  76 static gint ett_llc = -1;
  77 static gint ett_llc_ctrl = -1;
  78
  79 static dissector_table_t subdissector_table;
  80 static dissector_table_t xid_subdissector_table;
  81
  82 static dissector_handle_t bpdu_handle;
  83 static dissector_handle_t eth_handle;
  84 static dissector_handle_t fddi_handle;
  85 static dissector_handle_t tr_handle;
  86 static dissector_handle_t data_handle;
  87
  88 /*
  89  * Group/Individual bit, in the DSAP.
  90  */
  91 #define DSAP_GI_BIT     0x01
  92
  93 /*
  94  * Command/Response bit, in the SSAP.
  95  *
  96  * The low-order bit of the SSAP apparently determines whether this
  97  * is a request or a response.  (RFC 1390, "Transmission of IP and
  98  * ARP over FDDI Networks", says
  99  *
 100  *      Command frames are identified by having the low order
 101  *      bit of the SSAP address reset to zero.  Response frames
 102  *      have the low order bit of the SSAP address set to one.
 103  *
 104  * and a page I've seen seems to imply that's part of 802.2.)
 105  */
 106 #define SSAP_CR_BIT     0x01
 107
 108 /*
 109  * Mask to extrace the SAP number from the DSAP or the SSAP.
 110  */
 111 #define SAP_MASK        0xFE
 112
 113 /*
 114  * These are for SSAP and DSAP, wth last bit always zero.
 115  * XXX - some DSAPs come in separate "individual" and "group" versions,
 116  * with the last bit 0 and 1, respectively (e.g., LLC Sub-layer Management,
 117  * IBM SNA Path Control, IBM Net Management), but, whilst 0xFE is
 118  * the ISO Network Layer Protocol, 0xFF is the Global LSAP.
 119  */
 120 const value_string sap_vals[] = {
 121         { SAP_NULL,           "NULL LSAP" },
 122         { SAP_LLC_SLMGMT,     "LLC Sub-Layer Management" },
 123         { SAP_SNA_PATHCTRL,   "SNA Path Control" },
 124         { SAP_IP,             "TCP/IP" },
 125         { SAP_SNA1,           "SNA" },
 126         { SAP_SNA2,           "SNA" },
 127         { SAP_PROWAY_NM_INIT, "PROWAY (IEC955) Network Management and Initialization" },
 128         { SAP_NETWARE1,       "NetWare (unofficial?)" },
 129         { SAP_OSINL1,         "ISO Network Layer (OSLAN 1)" },
 130         { SAP_TI,             "Texas Instruments" },
 131         { SAP_OSINL2,         "ISO Network Layer (unofficial?)" },
 132         { SAP_OSINL3,         "ISO Network Layer (unofficial?)" },
 133         { SAP_BPDU,           "Spanning Tree BPDU" },
 134         { SAP_RS511,          "EIA RS-511 Manufacturing Message Service" },
 135         { SAP_OSINL4,         "ISO Network Layer (OSLAN 2)" },
 136         { SAP_X25,            "ISO 8208 (X.25 over 802.2)" },
 137         /*
 138          * XXX - setting the group bit of SAP_X25 make 0x7F; is this just
 139          * a group version of that?
 140          */
 141         { 0x7F,               "ISO 802.2" },
 142         { SAP_XNS,            "XNS" },
 143         { SAP_BACNET,         "BACnet" },
 144         { SAP_NESTAR,         "Nestar" },
 145         { SAP_PROWAY_ASLM,    "PROWAY (IEC955) Active Station List Maintenance" },
 146         { SAP_ARP,            "ARP" },  /* XXX - hand to "dissect_arp()"? */
 147         { SAP_SNAP,           "SNAP" },
 148         { SAP_VINES1,         "Banyan Vines" },
 149         { SAP_VINES2,         "Banyan Vines" },
 150         { SAP_NETWARE2,       "NetWare" },
 151         { SAP_NETBIOS,        "NetBIOS" },
 152         { SAP_IBMNM,          "IBM Net Management" },
 153         { SAP_HPEXT,          "HP Extended LLC" },
 154         { SAP_UB,             "Ungermann-Bass" },
 155         { SAP_RPL,            "Remote Program Load" },
 156         { SAP_OSINL5,         "ISO Network Layer" },
 157         { SAP_GLOBAL,         "Global LSAP" },
 158         { 0x00,               NULL }
 159 };
 160
 161 /*
 162  * See
 163  *
 164  * http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/vlan.htm
 165  *
 166  * for the PIDs for VTP and DRiP that go with an OUI of OUI_CISCO.
 167  */
 168 const value_string oui_vals[] = {
 169         { OUI_ENCAP_ETHER, "Encapsulated Ethernet" },
 170 /*
 171 http://www.cisco.com/univercd/cc/td/doc/product/software/ios113ed/113ed_cr/ibm_r/brprt1/brsrb.htm
 172 */
 173         { OUI_CISCO,       "Cisco" },
 174         { OUI_CISCO_90,    "Cisco IOS 9.0 Compatible" },
 175         { OUI_BRIDGED,     "Frame Relay or ATM bridged frames" },
 176                                 /* RFC 2427, RFC 2684 */
 177         { OUI_ATM_FORUM,   "ATM Forum" },
 178         { OUI_CABLE_BPDU,  "DOCSIS Spanning Tree" }, /* DOCSIS spanning tree BPDU */
 179         { OUI_APPLE_ATALK, "Apple (AppleTalk)" },
 180         { OUI_NORTEL,      "Nortel Networks SONMP" },
 181         { 0,               NULL }
 182 };
 183
 184 /*
 185  * Hash table for translating OUIs to a dissector table/field info pair;
 186  * the dissector table maps PID values to dissectors, and the field
 187  * corresponds to the PID for that OUI.
 188  */
 189 typedef struct {
 190         dissector_table_t table;
 191         hf_register_info *field_info;
 192 } oui_info_t;
 193
 194 static GHashTable *oui_info_table = NULL;
 195
 196 /*
 197  * Add an entry for a new OUI.
 198  */
 199 void
 200 llc_add_oui(guint32 oui, const char *table_name, char *table_ui_name,
 201     hf_register_info *hf_item)
 202 {
 203         oui_info_t *new_info;
 204
 205         new_info = g_malloc(sizeof (oui_info_t));
 206         new_info->table = register_dissector_table(table_name,
 207             table_ui_name, FT_UINT16, BASE_HEX);
 208         new_info->field_info = hf_item;
 209
 210         /*
 211          * Create the hash table for OUI information, if it doesn't
 212          * already exist.
 213          */
 214         if (oui_info_table == NULL) {
 215                 oui_info_table = g_hash_table_new(g_direct_hash,
 216                     g_direct_equal);
 217         }
 218         g_hash_table_insert(oui_info_table, (gpointer)oui, new_info);
 219 }
 220
 221 void
 222 capture_llc(const guchar *pd, int offset, int len, packet_counts *ld) {
 223
 224         int             is_snap;
 225         guint16         control;
 226         int             llc_header_len;
 227         guint32         oui;
 228         guint16         etype;
 229
 230         if (!BYTES_ARE_IN_FRAME(offset, len, 2)) {
 231                 ld->other++;
 232                 return;
 233         }
 234         is_snap = (pd[offset] == SAP_SNAP) && (pd[offset+1] == SAP_SNAP);
 235         llc_header_len = 2;     /* DSAP + SSAP */
 236
 237         /*
 238          * XXX - the page referred to in the comment above about the
 239          * Command/Response bit also implies that LLC Type 2 always
 240          * uses extended operation, so we don't need to determine
 241          * whether it's basic or extended operation; is that the case?
 242          */
 243         control = get_xdlc_control(pd, offset+2, pd[offset+1] & SSAP_CR_BIT);
 244         llc_header_len += XDLC_CONTROL_LEN(control, TRUE);
 245         if (is_snap)
 246                 llc_header_len += 5;    /* 3 bytes of OUI, 2 bytes of protocol ID */
 247         if (!BYTES_ARE_IN_FRAME(offset, len, llc_header_len)) {
 248                 ld->other++;
 249                 return;
 250         }
 251
 252         if (is_snap) {
 253                 oui = pd[offset+3] << 16 | pd[offset+4] << 8 | pd[offset+5];
 254                 if (XDLC_IS_INFORMATION(control)) {
 255                         etype = pntohs(&pd[offset+6]);
 256                         switch (oui) {
 257
 258                         case OUI_ENCAP_ETHER:
 259                         case OUI_CISCO_90:
 260                         case OUI_APPLE_ATALK:
 261                                 /* No, I have no idea why Apple used
 262                                    one of their own OUIs, rather than
 263                                    OUI_ENCAP_ETHER, and an Ethernet
 264                                    packet type as protocol ID, for
 265                                    AppleTalk data packets - but used
 266                                    OUI_ENCAP_ETHER and an Ethernet
 267                                    packet type for AARP packets. */
 268                                 capture_ethertype(etype, pd, offset+8, len,
 269                                     ld);
 270                                 break;
 271                         case OUI_CISCO:
 272                                 capture_ethertype(etype, pd, offset + 8, len,
 273                                     ld);
 274                                 break;
 275                         default:
 276                                 ld->other++;
 277                                 break;
 278                         }
 279                 }
 280         }
 281         else {
 282                 /* non-SNAP */
 283                 if (XDLC_IS_INFORMATION(control)) {
 284                         switch (pd[offset]) {
 285
 286                         case SAP_IP:
 287                                 capture_ip(pd, offset + llc_header_len, len,
 288                                     ld);
 289                                 break;
 290
 291                         case SAP_NETWARE1:
 292                         case SAP_NETWARE2:
 293                                 capture_ipx(ld);
 294                                 break;
 295
 296                         case SAP_NETBIOS:
 297                                 capture_netbios(ld);
 298                                 break;
 299
 300                         case SAP_VINES1:
 301                         case SAP_VINES2:
 302                                 capture_vines(ld);
 303                                 break;
 304
 305                         default:
 306                                 ld->other++;
 307                                 break;
 308                         }
 309                 }
 310         }
 311 }
 312
 313 /* Used only for U frames */
 314 static const xdlc_cf_items llc_cf_items = {
 315         NULL,
 316         NULL,
 317         &hf_llc_p,
 318         &hf_llc_f,
 319         NULL,
 320         &hf_llc_u_modifier_cmd,
 321         &hf_llc_u_modifier_resp,
 322         NULL,
 323         &hf_llc_ftype_s_u
 324 };
 325
 326 /* Used only for I and S frames */
 327 static const xdlc_cf_items llc_cf_items_ext = {
 328         &hf_llc_n_r,
 329         &hf_llc_n_s,
 330         &hf_llc_p_ext,
 331         &hf_llc_f_ext,
 332         &hf_llc_s_ftype,
 333         NULL,
 334         NULL,
 335         &hf_llc_ftype_i,
 336         &hf_llc_ftype_s_u_ext
 337 };
 338
 339 static void
 340 dissect_llc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 341 {
 342         proto_tree      *llc_tree = NULL;
 343         proto_item      *ti = NULL;
 344         int             is_snap;
 345         guint16         control;
 346         int             llc_header_len;
 347         guint8          dsap, ssap;
 348         tvbuff_t        *next_tvb;
 349
 350         if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
 351                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "LLC");
 352         }
 353         if (check_col(pinfo->cinfo, COL_INFO)) {
 354                 col_clear(pinfo->cinfo, COL_INFO);
 355         }
 356
 357         dsap = tvb_get_guint8(tvb, 0);
 358         if (tree) {
 359                 ti = proto_tree_add_item(tree, proto_llc, tvb, 0, -1, FALSE);
 360                 llc_tree = proto_item_add_subtree(ti, ett_llc);
 361                 proto_tree_add_uint(llc_tree, hf_llc_dsap, tvb, 0,
 362                         1, dsap & SAP_MASK);
 363                 proto_tree_add_boolean(llc_tree, hf_llc_dsap_ig, tvb, 0,
 364                         1, dsap & DSAP_GI_BIT);
 365         } else
 366                 llc_tree = NULL;
 367
 368         ssap = tvb_get_guint8(tvb, 1);
 369         if (tree) {
 370                 proto_tree_add_uint(llc_tree, hf_llc_ssap, tvb, 1,
 371                         1, ssap & SAP_MASK);
 372                 proto_tree_add_boolean(llc_tree, hf_llc_ssap_cr, tvb, 1,
 373                         1, ssap & SSAP_CR_BIT);
 374         } else
 375                 llc_tree = NULL;
 376
 377         is_snap = (dsap == SAP_SNAP) && (ssap == SAP_SNAP);
 378         llc_header_len = 2;     /* DSAP + SSAP */
 379
 380         /*
 381          * XXX - the page referred to in the comment above about the
 382          * Command/Response bit also implies that LLC Type 2 always
 383          * uses extended operation, so we don't need to determine
 384          * whether it's basic or extended operation; is that the case?
 385          */
 386         control = dissect_xdlc_control(tvb, 2, pinfo, llc_tree,
 387                                 hf_llc_ctrl, ett_llc_ctrl,
 388                                 &llc_cf_items, &llc_cf_items_ext,
 389                                 NULL, NULL, ssap & SSAP_CR_BIT, TRUE, FALSE);
 390         llc_header_len += XDLC_CONTROL_LEN(control, TRUE);
 391         if (is_snap)
 392                 llc_header_len += 5;    /* 3 bytes of OUI, 2 bytes of protocol ID */
 393
 394         if (tree)
 395                 proto_item_set_len(ti, llc_header_len);
 396
 397         if (is_snap) {
 398                 dissect_snap(tvb, 3, pinfo, tree, llc_tree, control,
 399                     hf_llc_oui, hf_llc_type, hf_llc_pid, 2);
 400         }
 401         else {
 402                 if (check_col(pinfo->cinfo, COL_INFO)) {
 403                         col_append_fstr(pinfo->cinfo, COL_INFO,
 404                             "; DSAP %s %s, SSAP %s %s",
 405                             val_to_str(dsap & SAP_MASK, sap_vals, "%02x"),
 406                             dsap & DSAP_GI_BIT ?
 407                               "Group" : "Individual",
 408                             val_to_str(ssap & SAP_MASK, sap_vals, "%02x"),
 409                             ssap & SSAP_CR_BIT ?
 410                               "Response" : "Command"
 411                         );
 412                 }
 413
 414                 if (tvb_length_remaining(tvb, llc_header_len) > 0) {
 415                         next_tvb = tvb_new_subset(tvb, llc_header_len, -1, -1);
 416                         if (XDLC_IS_INFORMATION(control)) {
 417                                 /*
 418                                  * Non-SNAP I or UI frame.
 419                                  * Try the regular LLC subdissector table
 420                                  * with the DSAP.
 421                                  */
 422                                 if (!dissector_try_port(subdissector_table,
 423                                     dsap, next_tvb, pinfo, tree)) {
 424                                         call_dissector(data_handle, next_tvb,
 425                                             pinfo, tree);
 426                                 }
 427                         } else if ((control & (XDLC_U_MODIFIER_MASK|XDLC_U))
 428                             == (XDLC_XID|XDLC_U)) {
 429                                 /*
 430                                  * Non-SNAP XID frame.
 431                                  * Try the XID LLC subdissector table
 432                                  * with the DSAP.
 433                                  */
 434                                 if (!dissector_try_port(xid_subdissector_table,
 435                                     dsap, next_tvb, pinfo, tree)) {
 436                                         call_dissector(data_handle, next_tvb,
 437                                             pinfo, tree);
 438                                 }
 439                         } else {
 440                                 call_dissector(data_handle, next_tvb, pinfo,
 441                                     tree);
 442                         }
 443                 }
 444         }
 445 }
 446
 447 /*
 448  * Dissect SNAP header; used elsewhere, e.g. in the Frame Relay dissector.
 449  */
 450 void
 451 dissect_snap(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree,
 452     proto_tree *snap_tree, int control, int hf_oui, int hf_type, int hf_pid,
 453     int bridge_pad)
 454 {
 455         guint32         oui;
 456         guint16         etype;
 457         tvbuff_t        *next_tvb;
 458         oui_info_t      *oui_info;
 459         dissector_table_t subdissector_table;
 460         int             hf;
 461
 462         oui =   tvb_get_ntoh24(tvb, offset);
 463         etype = tvb_get_ntohs(tvb, offset+3);
 464
 465         if (check_col(pinfo->cinfo, COL_INFO)) {
 466                 col_append_fstr(pinfo->cinfo, COL_INFO,
 467                     "; SNAP, OUI 0x%06X (%s), PID 0x%04X",
 468                     oui, val_to_str(oui, oui_vals, "Unknown"), etype);
 469         }
 470         if (tree) {
 471                 proto_tree_add_uint(snap_tree, hf_oui, tvb, offset, 3, oui);
 472         }
 473
 474         switch (oui) {
 475
 476         case OUI_ENCAP_ETHER:
 477         case OUI_CISCO_90:
 478         case OUI_APPLE_ATALK:
 479                 /* No, I have no idea why Apple used
 480                    one of their own OUIs, rather than
 481                    OUI_ENCAP_ETHER, and an Ethernet
 482                    packet type as protocol ID, for
 483                    AppleTalk data packets - but used
 484                    OUI_ENCAP_ETHER and an Ethernet
 485                    packet type for AARP packets. */
 486                 if (XDLC_IS_INFORMATION(control)) {
 487                         ethertype(etype, tvb, offset+5,
 488                             pinfo, tree, snap_tree, hf_type, -1, 0);
 489                 } else {
 490                         next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 491                         call_dissector(data_handle,next_tvb, pinfo, tree);
 492                 }
 493                 break;
 494
 495         case OUI_BRIDGED:
 496                 /*
 497                  * MAC frames bridged over ATM (RFC 2684) or Frame Relay
 498                  * (RFC 2427).
 499                  *
 500                  * We have to figure out how much padding to put
 501                  * into the frame.  We were handed a "bridge_pad"
 502                  * argument which should be 0 for Frame Relay and
 503                  * 2 for ATM; we add to that the amount of padding
 504                  * common to both bridging types.
 505                  */
 506                 if (tree) {
 507                         proto_tree_add_uint(snap_tree, hf_pid, tvb, offset+3, 2,
 508                             etype);
 509                 }
 510
 511                 switch (etype) {
 512
 513                 case BPID_ETH_WITH_FCS:
 514                 case BPID_ETH_WITHOUT_FCS:
 515                         next_tvb = tvb_new_subset(tvb, offset+5+bridge_pad,
 516                             -1, -1);
 517                         call_dissector(eth_handle, next_tvb, pinfo, tree);
 518                         break;
 519
 520                 case BPID_802_5_WITH_FCS:
 521                 case BPID_802_5_WITHOUT_FCS:
 522                         /*
 523                          * We treat the last padding byte as the Access
 524                          * Control byte, as that's what the Token
 525                          * Ring dissector expects the first byte to
 526                          * be.
 527                          */
 528                         next_tvb = tvb_new_subset(tvb, offset+5+bridge_pad,
 529                             -1, -1);
 530                         call_dissector(tr_handle, next_tvb, pinfo, tree);
 531                         break;
 532
 533                 case BPID_FDDI_WITH_FCS:
 534                 case BPID_FDDI_WITHOUT_FCS:
 535                         next_tvb = tvb_new_subset(tvb, offset+5+1+bridge_pad,
 536                             -1, -1);
 537                         call_dissector(fddi_handle, next_tvb, pinfo, tree);
 538                         break;
 539
 540                 case BPID_BPDU:
 541                         next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 542                         call_dissector(bpdu_handle, next_tvb, pinfo, tree);
 543                         break;
 544
 545                 default:
 546                         next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 547                         call_dissector(data_handle,next_tvb, pinfo, tree);
 548                         break;
 549                 }
 550                 break;
 551
 552         case OUI_CABLE_BPDU:    /* DOCSIS cable modem spanning tree BPDU */
 553                 if (tree) {
 554                         proto_tree_add_uint(snap_tree, hf_pid, tvb, offset+3, 2,
 555                             etype);
 556                 }
 557                 next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 558                 call_dissector(bpdu_handle, next_tvb, pinfo, tree);
 559                 break;
 560
 561         default:
 562                 /*
 563                  * Do we have information for this OUI?
 564                  */
 565                 oui_info = g_hash_table_lookup(oui_info_table, (gpointer)oui);
 566                 if (oui_info != NULL) {
 567                         /*
 568                          * Yes - use it.
 569                          */
 570                         hf = *oui_info->field_info->p_id;
 571                         subdissector_table = oui_info->table;
 572                 } else {
 573                         /*
 574                          * No, use hf_pid for the PID and just dissect
 575                          * the payload as data.
 576                          */
 577                         hf = hf_pid;
 578                         subdissector_table = NULL;
 579                 }
 580                 if (tree) {
 581                         proto_tree_add_uint(snap_tree, hf, tvb, offset+3, 2,
 582                             etype);
 583                 }
 584                 next_tvb = tvb_new_subset(tvb, offset+5, -1, -1);
 585                 if (XDLC_IS_INFORMATION(control)) {
 586                         if (subdissector_table != NULL) {
 587                                 /* do lookup with the subdissector table */
 588                                 if (dissector_try_port(subdissector_table,
 589                                     etype, next_tvb, pinfo, tree))
 590                                         break;
 591                         }
 592                 }
 593                 call_dissector(data_handle, next_tvb, pinfo, tree);
 594                 break;
 595         }
 596 }
 597
 598 void
 599 proto_register_llc(void)
 600 {
 601         static struct true_false_string ig_bit = { "Group", "Individual" };
 602         static struct true_false_string cr_bit = { "Response", "Command" };
 603
 604         static hf_register_info hf[] = {
 605                 { &hf_llc_dsap,
 606                 { "DSAP",       "llc.dsap", FT_UINT8, BASE_HEX,
 607                         VALS(sap_vals), 0x0, "", HFILL }},
 608
 609                 { &hf_llc_dsap_ig,
 610                 { "IG Bit",     "llc.dsap.ig", FT_BOOLEAN, BASE_HEX,
 611                         &ig_bit, 0x0, "Individual/Group", HFILL }},
 612
 613                 { &hf_llc_ssap,
 614                 { "SSAP", "llc.ssap", FT_UINT8, BASE_HEX,
 615                         VALS(sap_vals), 0x0, "", HFILL }},
 616
 617                 { &hf_llc_ssap_cr,
 618                 { "CR Bit", "llc.ssap.cr", FT_BOOLEAN, BASE_HEX,
 619                         &cr_bit, 0x0, "Command/Response", HFILL }},
 620
 621                 { &hf_llc_ctrl,
 622                 { "Control", "llc.control", FT_UINT16, BASE_HEX,
 623                         NULL, 0x0, "", HFILL }},
 624
 625                 { &hf_llc_n_r,
 626                 { "N(R)", "llc.control.n_r", FT_UINT16, BASE_DEC,
 627                         NULL, XDLC_N_R_EXT_MASK, "", HFILL }},
 628
 629                 { &hf_llc_n_s,
 630                 { "N(S)", "llc.control.n_s", FT_UINT16, BASE_DEC,
 631                         NULL, XDLC_N_S_EXT_MASK, "", HFILL }},
 632
 633                 { &hf_llc_p,
 634                 { "Poll", "llc.control.p", FT_BOOLEAN, 8,
 635                         TFS(&flags_set_truth), XDLC_P_F, "", HFILL }},
 636
 637                 { &hf_llc_p_ext,
 638                 { "Poll", "llc.control.p", FT_BOOLEAN, 16,
 639                         TFS(&flags_set_truth), XDLC_P_F_EXT, "", HFILL }},
 640
 641                 { &hf_llc_f,
 642                 { "Final", "llc.control.f", FT_BOOLEAN, 8,
 643                         TFS(&flags_set_truth), XDLC_P_F, "", HFILL }},
 644
 645                 { &hf_llc_f_ext,
 646                 { "Final", "llc.control.f", FT_BOOLEAN, 16,
 647                         TFS(&flags_set_truth), XDLC_P_F_EXT, "", HFILL }},
 648
 649                 { &hf_llc_s_ftype,
 650                 { "Supervisory frame type", "llc.control.s_ftype", FT_UINT16, BASE_HEX,
 651                         VALS(stype_vals), XDLC_S_FTYPE_MASK, "", HFILL }},
 652
 653                 { &hf_llc_u_modifier_cmd,
 654                 { "Command", "llc.control.u_modifier_cmd", FT_UINT8, BASE_HEX,
 655                         VALS(modifier_vals_cmd), XDLC_U_MODIFIER_MASK, "", HFILL }},
 656
 657                 { &hf_llc_u_modifier_resp,
 658                 { "Response", "llc.control.u_modifier_resp", FT_UINT8, BASE_HEX,
 659                         VALS(modifier_vals_resp), XDLC_U_MODIFIER_MASK, "", HFILL }},
 660
 661                 { &hf_llc_ftype_i,
 662                 { "Frame type", "llc.control.ftype", FT_UINT16, BASE_HEX,
 663                         VALS(ftype_vals), XDLC_I_MASK, "", HFILL }},
 664
 665                 { &hf_llc_ftype_s_u,
 666                 { "Frame type", "llc.control.ftype", FT_UINT8, BASE_HEX,
 667                         VALS(ftype_vals), XDLC_S_U_MASK, "", HFILL }},
 668
 669                 { &hf_llc_ftype_s_u_ext,
 670                 { "Frame type", "llc.control.ftype", FT_UINT16, BASE_HEX,
 671                         VALS(ftype_vals), XDLC_S_U_MASK, "", HFILL }},
 672
 673                 /* registered here but handled in ethertype.c */
 674                 { &hf_llc_type,
 675                 { "Type", "llc.type", FT_UINT16, BASE_HEX,
 676                         VALS(etype_vals), 0x0, "", HFILL }},
 677
 678                 { &hf_llc_oui,
 679                 { "Organization Code",  "llc.oui", FT_UINT24, BASE_HEX,
 680                         VALS(oui_vals), 0x0, "", HFILL }},
 681
 682                 { &hf_llc_pid,
 683                 { "Protocol ID", "llc.pid", FT_UINT16, BASE_HEX,
 684                         NULL, 0x0, "", HFILL }}
 685         };
 686         static gint *ett[] = {
 687                 &ett_llc,
 688                 &ett_llc_ctrl,
 689         };
 690
 691         proto_llc = proto_register_protocol("Logical-Link Control", "LLC", "llc");
 692         proto_register_field_array(proto_llc, hf, array_length(hf));
 693         proto_register_subtree_array(ett, array_length(ett));
 694
 695 /* subdissector code */
 696         subdissector_table = register_dissector_table("llc.dsap",
 697           "LLC SAP", FT_UINT8, BASE_HEX);
 698         xid_subdissector_table = register_dissector_table("llc.xid_dsap",
 699           "LLC XID SAP", FT_UINT8, BASE_HEX);
 700
 701         register_dissector("llc", dissect_llc, proto_llc);
 702 }
 703
 704 static void
 705 register_hf(gpointer key _U_, gpointer value, gpointer user_data _U_)
 706 {
 707         oui_info_t *info = value;
 708
 709         proto_register_field_array(proto_llc, info->field_info, 1);
 710 }
 711
 712 void
 713 proto_reg_handoff_llc(void)
 714 {
 715         dissector_handle_t llc_handle;
 716
 717         /*
 718          * Get handles for the BPDU, Ethernet, FDDI, and Token Ring
 719          * dissectors.
 720          */
 721         bpdu_handle = find_dissector("bpdu");
 722         eth_handle = find_dissector("eth");
 723         fddi_handle = find_dissector("fddi");
 724         tr_handle = find_dissector("tr");
 725         data_handle = find_dissector("data");
 726
 727         llc_handle = find_dissector("llc");
 728         dissector_add("wtap_encap", WTAP_ENCAP_ATM_RFC1483, llc_handle);
 729         /* RFC 2043 */
 730         dissector_add("ppp.protocol", PPP_LLC, llc_handle);
 731         /* RFC 2353 */
 732         dissector_add("udp.port", UDP_PORT_LLC1, llc_handle);
 733         dissector_add("udp.port", UDP_PORT_LLC2, llc_handle);
 734         dissector_add("udp.port", UDP_PORT_LLC3, llc_handle);
 735         dissector_add("udp.port", UDP_PORT_LLC4, llc_handle);
 736         dissector_add("udp.port", UDP_PORT_LLC5, llc_handle);
 737         /* IP-over-FC when we have the full FC frame */
 738         dissector_add("fc.ftype", FC_FTYPE_IP, llc_handle);
 739
 740         /*
 741          * BACNET-over-ARCNET is really BACNET-over-802.2 LLC-over-ARCNET,
 742          * apparently.
 743          */
 744         dissector_add("arcnet.protocol_id", ARCNET_PROTO_BACNET, llc_handle);
 745
 746         /*
 747          * Register all the fields for PIDs for various OUIs.
 748          */
 749         g_hash_table_foreach(oui_info_table, register_hf, NULL);
 750 }