daeac95d4a
have other dissectors that use them fetch them with "find_dissector_table()". svn path=/trunk/; revision=7601
439 lines
15 KiB
C
439 lines
15 KiB
C
/* packet-fr.c
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* Routines for Frame Relay dissection
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*
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* Copyright 2001, Paul Ionescu <paul@acorp.ro>
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*
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* $Id: packet-fr.c,v 1.34 2003/04/29 17:56:47 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* References:
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*
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* http://www.protocols.com/pbook/frame.htm
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* http://www.frforum.com/5000/Approved/FRF.3/FRF.3.2.pdf
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* ITU Recommendation Q.933
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* RFC-1490
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* RFC-2427
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* Cisco encapsulation
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* http://www.trillium.com/whats-new/wp_frmrly.html
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <ctype.h>
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#include <string.h>
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#include <glib.h>
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#include <epan/packet.h>
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#include "packet-llc.h"
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#include "packet-chdlc.h"
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#include "xdlc.h"
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#include "etypes.h"
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#include "oui.h"
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#include "nlpid.h"
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#include "greproto.h"
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#include <epan/conversation.h>
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/*
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* Bits in the address field.
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*/
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#define FRELAY_DLCI 0xfcf0 /* 2 byte DLCI Address */
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#define FRELAY_CR 0x0200 /* Command/Response bit */
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#define FRELAY_EA 0x0001 /* Address Extension bit */
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#define FRELAY_FECN 0x0008 /* Forward Explicit Congestion Notification */
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#define FRELAY_BECN 0x0004 /* Backward Explicit Congestion Notification */
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#define FRELAY_DE 0x0002 /* Discard Eligibility */
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#define FRELAY_DC 0x0002 /* Control bits */
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/*
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* Extract the DLCI from the address field.
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*/
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#define EXTRACT_DLCI(addr) ((((addr)&0xfc00) >> 6) | (((addr)&0xf0) >> 4))
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#define FROM_DCE 0x80 /* for direction setting */
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static gint proto_fr = -1;
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static gint ett_fr = -1;
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static gint hf_fr_dlci = -1;
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static gint hf_fr_cr = -1;
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static gint hf_fr_becn = -1;
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static gint hf_fr_fecn = -1;
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static gint hf_fr_de = -1;
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static gint hf_fr_ea = -1;
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static gint hf_fr_dc = -1;
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static gint hf_fr_nlpid = -1;
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static gint hf_fr_oui = -1;
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static gint hf_fr_pid = -1;
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static gint hf_fr_snaptype = -1;
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static gint hf_fr_chdlctype = -1;
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static dissector_handle_t data_handle;
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static dissector_table_t osinl_subdissector_table;
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static const true_false_string cmd_string = {
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"Command",
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"Response"
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};
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static const true_false_string ctrl_string = {
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"DLCI Address",
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"Control"
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};
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static const true_false_string ea_string = {
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"Last Octet",
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"More Follows"
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};
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/*
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* This isn't the same as "nlpid_vals[]"; 0x08 is Q.933, not Q.931,
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* and 0x09 is LMI, not Q.2931, and we assume that it's an initial
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* protocol identifier, so 0x01 is T.70, not X.29.
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*/
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static const value_string fr_nlpid_vals[] = {
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{ NLPID_NULL, "NULL" },
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{ NLPID_IPI_T_70, "T.70" }, /* XXX - IPI, or SPI? */
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{ NLPID_X_633, "X.633" },
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{ NLPID_Q_931, "Q.933" },
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{ NLPID_LMI, "LMI" },
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{ NLPID_Q_2119, "Q.2119" },
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{ NLPID_SNAP, "SNAP" },
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{ NLPID_ISO8473_CLNP, "CLNP" },
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{ NLPID_ISO9542_ESIS, "ESIS" },
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{ NLPID_ISO10589_ISIS, "ISIS" },
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{ NLPID_ISO10747_IDRP, "IDRP" },
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{ NLPID_ISO9542X25_ESIS, "ESIS (X.25)" },
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{ NLPID_ISO10030, "ISO 10030" },
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{ NLPID_ISO11577, "ISO 11577" },
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{ NLPID_COMPRESSED, "Data compression protocol" },
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{ NLPID_IP, "IP" },
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{ NLPID_IP6, "IPv6" },
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{ NLPID_PPP, "PPP" },
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{ 0, NULL },
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};
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static dissector_table_t fr_subdissector_table;
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static void dissect_fr_nlpid(tvbuff_t *tvb, int offset, packet_info *pinfo,
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proto_tree *tree, proto_item *ti,
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proto_tree *fr_tree, guint8 fr_ctrl);
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static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
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static void dissect_fr_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
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static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_item *ti = NULL;
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proto_tree *fr_tree = NULL;
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guint16 fr_header,fr_type,offset=2; /* default header length of FR is 2 bytes */
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guint16 address;
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char buf[32];
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guint8 fr_ctrl;
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "FR");
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if (pinfo->pseudo_header->x25.flags & FROM_DCE) {
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if(check_col(pinfo->cinfo, COL_RES_DL_DST))
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col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
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if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
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col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
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}
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else {
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if(check_col(pinfo->cinfo, COL_RES_DL_DST))
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col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
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if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
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col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
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}
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/*XXX We should check the EA bits and use that to generate the address. */
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fr_header = tvb_get_ntohs(tvb, 0);
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fr_ctrl = tvb_get_guint8( tvb, 2);
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address = EXTRACT_DLCI(fr_header);
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pinfo->ctype = CT_DLCI;
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pinfo->circuit_id = address;
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if (check_col(pinfo->cinfo, COL_INFO))
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col_add_fstr(pinfo->cinfo, COL_INFO, "DLCI %u", address);
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if (tree) {
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ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 3, "Frame Relay");
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fr_tree = proto_item_add_subtree(ti, ett_fr);
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decode_bitfield_value(buf, fr_header, FRELAY_DLCI, 16);
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proto_tree_add_uint_format(fr_tree, hf_fr_dlci, tvb, 0, 2, address,
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"%sDLCI: %u", buf, address);
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proto_tree_add_boolean(fr_tree, hf_fr_cr, tvb, 0, offset, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_fecn, tvb, 0, offset, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_becn, tvb, 0, offset, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_de, tvb, 0, offset, fr_header);
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proto_tree_add_boolean(fr_tree, hf_fr_ea, tvb, 0, offset, fr_header);
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}
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if (fr_ctrl == XDLC_U) {
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if (tree) {
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proto_tree_add_text(fr_tree, tvb, offset, 0, "------- Q.933 Encapsulation -------");
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/*
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* XXX - if we're going to show this as Unnumbered
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* Information, should we just hand it to
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* "dissect_xdlc_control()"?
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*/
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proto_tree_add_text(fr_tree, tvb, offset, 1, "Unnumbered Information");
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}
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offset++;
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dissect_fr_nlpid(tvb, offset, pinfo, tree, ti, fr_tree, fr_ctrl);
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} else {
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if (address == 0) {
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/* this must be some sort of lapf on DLCI 0 for SVC */
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/* because DLCI 0 is rezerved for LMI and SVC signaling encaplulated in lapf */
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/* and LMI is transmitted in unnumbered information (03) */
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/* so this must be lapf (guessing) */
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dissect_lapf(tvb_new_subset(tvb,offset,-1,-1),pinfo,tree);
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return;
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}
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if (fr_ctrl == (XDLC_U|XDLC_XID)) {
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dissect_fr_xid(tvb_new_subset(tvb,offset,-1,-1),pinfo,tree);
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return;
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}
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/*
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* If the data does not start with unnumbered information (03) and
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* the DLCI# is not 0, then there may be Cisco Frame Relay encapsulation.
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*/
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proto_tree_add_text(fr_tree, tvb, offset, 0, "------- Cisco Encapsulation -------");
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fr_type = tvb_get_ntohs(tvb, offset);
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if (ti != NULL) {
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/* Include the Cisco HDLC type in the top-level protocol
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tree item. */
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proto_item_set_len(ti, offset+2);
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}
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chdlctype(fr_type, tvb, offset+2, pinfo, tree, fr_tree, hf_fr_chdlctype);
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}
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}
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static void dissect_fr_uncompressed(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *tree)
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{
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proto_item *ti = NULL;
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proto_tree *fr_tree = NULL;
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "FR");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_clear(pinfo->cinfo, COL_INFO);
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if (tree) {
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ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 4, "Frame Relay");
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fr_tree = proto_item_add_subtree(ti, ett_fr);
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}
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dissect_fr_nlpid(tvb, 0, pinfo, tree, ti, fr_tree, XDLC_U);
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}
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static void dissect_fr_nlpid(tvbuff_t *tvb, int offset, packet_info *pinfo,
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proto_tree *tree, proto_item *ti,
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proto_tree *fr_tree, guint8 fr_ctrl)
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{
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guint8 fr_nlpid;
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tvbuff_t *next_tvb;
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fr_nlpid = tvb_get_guint8 (tvb,offset);
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if (fr_nlpid == 0) {
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if (tree)
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proto_tree_add_text(fr_tree, tvb, offset, 1, "Padding");
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offset++;
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if (ti != NULL) {
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/* Include the padding in the top-level protocol tree item. */
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proto_item_set_len(ti, offset);
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}
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fr_nlpid=tvb_get_guint8( tvb,offset);
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}
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/*
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* OSI network layer protocols consider the NLPID to be part
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* of the frame, so we'll pass it as part of the payload and,
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* if the protocol is one of those, add it as a hidden item here.
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*/
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next_tvb = tvb_new_subset(tvb,offset,-1,-1);
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if (dissector_try_port(osinl_subdissector_table, fr_nlpid, next_tvb,
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pinfo, tree)) {
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/*
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* Yes, we got a match. Add the NLPID as a hidden item,
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* so you can, at least, filter on it.
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*/
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if (tree)
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proto_tree_add_uint_hidden(fr_tree, hf_fr_nlpid,
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tvb, offset, 1, fr_nlpid );
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return;
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}
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/*
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* All other protocols don't.
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*
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* XXX - not true for Q.933 and LMI, but we don't yet have a
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* Q.933 dissector (it'd be similar to the Q.931 dissector,
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* but I don't think it'd be identical, although it's less
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* different than is the Q.2931 dissector), and the LMI
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* dissector doesn't yet put the protocol discriminator
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* (NLPID) into the tree.
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*
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* Note that an NLPID of 0x08 for Q.933 could either be a
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* Q.933 signaling message or a message for a protocol
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* identified by a 2-octet layer 2 protocol type and a
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* 2-octet layer 3 protocol type, those protocol type
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* octets having the values from octets 6, 6a, 7, and 7a
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* of a Q.931 low layer compatibility information element
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* (section 4.5.19 of Q.931; Q.933 says they have the values
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* from a Q.933 low layer compatibility information element,
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* but Q.933 low layer compatibility information elements
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* don't have protocol values in them).
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*
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* Assuming that, as Q.933 seems to imply, that Q.933 messages
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* look just like Q.931 messages except where it explicitly
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* says they differ, then the octet after the NLPID would,
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* in a Q.933 message, have its upper 4 bits zero (that's
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* the length of the call reference value, in Q.931, and
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* is limited to 15 or fewer octets). As appears to be the case,
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* octet 6 of a Q.931 low layer compatibility element has the
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* 0x40 bit set, so you can distinguish between a Q.933
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* message and an encapsulated packet by checking whether
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* the upper 4 bits of the octet after the NLPID are zero.
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*
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* To handle this, we'd handle Q.933's NLPID specially, which
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* we'd want to do anyway, so that we give it a tvbuff that
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* includes the NLPID.
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*/
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if (tree)
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proto_tree_add_uint(fr_tree, hf_fr_nlpid, tvb, offset, 1, fr_nlpid );
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offset++;
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switch (fr_nlpid) {
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case NLPID_SNAP:
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if (ti != NULL) {
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/* Include the NLPID and SNAP header in the top-level
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protocol tree item. */
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proto_item_set_len(ti, offset+5);
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}
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dissect_snap(tvb, offset, pinfo, tree, fr_tree, fr_ctrl,
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hf_fr_oui, hf_fr_snaptype, hf_fr_pid, 0);
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return;
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default:
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if (ti != NULL) {
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/* Include the NLPID in the top-level protocol tree item. */
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proto_item_set_len(ti, offset);
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}
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next_tvb = tvb_new_subset(tvb,offset,-1,-1);
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if (!dissector_try_port(fr_subdissector_table,fr_nlpid,
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next_tvb, pinfo, tree))
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call_dissector(data_handle,next_tvb, pinfo, tree);
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break;
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}
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}
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static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree_add_text(tree, tvb, 0, 0, "Frame relay lapf not yet implemented");
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call_dissector(data_handle,tvb_new_subset(tvb,0,-1,-1),pinfo,tree);
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}
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static void dissect_fr_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree_add_text(tree, tvb, 0, 0, "Frame relay xid not yet implemented");
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call_dissector(data_handle,tvb_new_subset(tvb,0,-1,-1),pinfo,tree);
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}
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/* Register the protocol with Ethereal */
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void proto_register_fr(void)
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{
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static hf_register_info hf[] = {
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{ &hf_fr_dlci, {
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"DLCI", "fr.dlci", FT_UINT16, BASE_DEC,
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NULL, FRELAY_DLCI, "Data-Link Connection Identifier", HFILL }},
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{ &hf_fr_cr, {
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"CR", "fr.cr", FT_BOOLEAN, 16, TFS(&cmd_string),
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FRELAY_CR, "Command/Response", HFILL }},
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{ &hf_fr_dc, {
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"DC", "fr.dc", FT_BOOLEAN, 16, TFS(&ctrl_string),
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FRELAY_CR, "Address/Control", HFILL }},
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{ &hf_fr_fecn, {
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"FECN", "fr.fecn", FT_BOOLEAN, 16,
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NULL, FRELAY_FECN, "Forward Explicit Congestion Notification", HFILL }},
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{ &hf_fr_becn, {
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"BECN", "fr.becn", FT_BOOLEAN, 16,
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NULL, FRELAY_BECN, "Backward Explicit Congestion Notification", HFILL }},
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{ &hf_fr_de, {
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"DE", "fr.de", FT_BOOLEAN, 16,
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NULL, FRELAY_DE, "Discard Eligibility", HFILL }},
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{ &hf_fr_ea, {
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"EA", "fr.ea", FT_BOOLEAN, 16, TFS(&ea_string),
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FRELAY_EA, "Extended Address", HFILL }},
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{ &hf_fr_nlpid, {
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"NLPID", "fr.nlpid", FT_UINT8, BASE_HEX,
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VALS(fr_nlpid_vals), 0x0, "FrameRelay Encapsulated Protocol NLPID", HFILL }},
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{ &hf_fr_oui, {
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"Organization Code", "fr.snap.oui", FT_UINT24, BASE_HEX,
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VALS(oui_vals), 0x0, "", HFILL }},
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{ &hf_fr_pid, {
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"Protocol ID", "fr.snap.pid", FT_UINT16, BASE_HEX,
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NULL, 0x0, "", HFILL }},
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{ &hf_fr_snaptype, {
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"Type", "fr.snaptype", FT_UINT16, BASE_HEX,
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VALS(etype_vals), 0x0, "FrameRelay SNAP Encapsulated Protocol", HFILL }},
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{ &hf_fr_chdlctype, {
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"Type", "fr.chdlctype", FT_UINT16, BASE_HEX,
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VALS(chdlc_vals), 0x0, "FrameRelay Cisco HDLC Encapsulated Protocol", HFILL }},
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};
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/* Setup protocol subtree array */
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static gint *ett[] = {
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&ett_fr,
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};
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proto_fr = proto_register_protocol("Frame Relay", "FR", "fr");
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proto_register_field_array(proto_fr, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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fr_subdissector_table = register_dissector_table("fr.ietf",
|
|
"Frame Relay NLPID", FT_UINT8, BASE_HEX);
|
|
|
|
register_dissector("fr_uncompressed", dissect_fr_uncompressed, proto_fr);
|
|
register_dissector("fr", dissect_fr, proto_fr);
|
|
}
|
|
|
|
void proto_reg_handoff_fr(void)
|
|
{
|
|
dissector_handle_t fr_handle;
|
|
|
|
fr_handle = create_dissector_handle(dissect_fr, proto_fr);
|
|
dissector_add("wtap_encap", WTAP_ENCAP_FRELAY, fr_handle);
|
|
dissector_add("wtap_encap", WTAP_ENCAP_FRELAY_WITH_PHDR, fr_handle);
|
|
dissector_add("gre.proto", GRE_FR, fr_handle);
|
|
data_handle = find_dissector("data");
|
|
|
|
osinl_subdissector_table = find_dissector_table("osinl");
|
|
}
|