![Guy Harris](/assets/img/avatar_default.png)
argument to "tvb_new_subset()" - just use -1 if the subset tvbuff is to run to the end of the parent tvbuff. svn path=/trunk/; revision=5597
327 lines
9.4 KiB
C
327 lines
9.4 KiB
C
/* packet-chdlc.c
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* Routines for Cisco HDLC packet disassembly
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*
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* $Id: packet-chdlc.c,v 1.13 2002/05/30 01:56:54 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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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#include <glib.h>
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#include <epan/packet.h>
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#include "etypes.h"
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#include <epan/resolv.h>
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#include "packet-chdlc.h"
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#include "packet-ip.h"
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/*
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* See section 4.3.1 of RFC 1547, and
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*
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* http://www.nethelp.no/net/cisco-hdlc.txt
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*/
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static int proto_chdlc = -1;
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static int hf_chdlc_addr = -1;
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static int hf_chdlc_proto = -1;
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static gint ett_chdlc = -1;
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static int proto_slarp = -1;
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static int hf_slarp_ptype = -1;
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static int hf_slarp_address = -1;
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static int hf_slarp_mysequence = -1;
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static int hf_slarp_yoursequence = -1;
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static gint ett_slarp = -1;
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static dissector_handle_t data_handle;
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/*
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* Protocol types for the Cisco HDLC format.
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*
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* As per the above, according to RFC 1547, these are "standard 16 bit
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* Ethernet protocol type code[s]", but 0x8035 is Reverse ARP, and
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* that is (at least according to the Linux ISDN code) not the
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* same as Cisco SLARP.
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*
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* In addition, 0x2000 is apparently the Cisco Discovery Protocol, but
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* on Ethernet those are encapsulated inside SNAP with an OUI of
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* OUI_CISCO, not OUI_ENCAP_ETHER.
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*
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* Perhaps we should set up a protocol table for those protocols
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* that differ between Ethernet and Cisco HDLC, and have the PPP
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* code first try that table and, if it finds nothing in that
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* table, call "ethertype()". (Unfortunately, that means that -
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* assuming we had a Cisco SLARP dissector - said dissector were
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* disabled, SLARP packets would be dissected as Reverse ARP
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* packets, not as data.)
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*/
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#define CISCO_SLARP 0x8035 /* Cisco SLARP protocol */
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static dissector_table_t subdissector_table;
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static const value_string chdlc_address_vals[] = {
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{CHDLC_ADDR_UNICAST, "Unicast"},
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{CHDLC_ADDR_MULTICAST, "Multicast"},
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{0, NULL}
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};
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const value_string chdlc_vals[] = {
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{0x2000, "Cisco Discovery Protocol"},
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{ETHERTYPE_IP, "IP"},
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{CISCO_SLARP, "SLARP"},
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{ETHERTYPE_DEC_LB, "DEC LanBridge"},
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{ETHERTYPE_ATALK, "Appletalk"},
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{ETHERTYPE_AARP, "AARP"},
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{ETHERTYPE_IPX, "Netware IPX/SPX"},
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{ETHERTYPE_ETHBRIDGE, "Transparent Ethernet bridging" },
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{0, NULL}
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};
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void
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capture_chdlc( const u_char *pd, int offset, int len, packet_counts *ld ) {
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if (!BYTES_ARE_IN_FRAME(offset, len, 2)) {
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ld->other++;
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return;
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}
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switch (pntohs(&pd[offset + 2])) {
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case ETHERTYPE_IP:
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capture_ip(pd, offset + 4, len, ld);
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break;
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default:
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ld->other++;
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break;
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}
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}
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void
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chdlctype(guint16 chdlctype, tvbuff_t *tvb, int offset_after_chdlctype,
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packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
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int chdlctype_id)
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{
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tvbuff_t *next_tvb;
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if (tree) {
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proto_tree_add_uint(fh_tree, chdlctype_id, tvb,
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offset_after_chdlctype - 2, 2, chdlctype);
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}
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next_tvb = tvb_new_subset(tvb, offset_after_chdlctype, -1, -1);
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/* do lookup with the subdissector table */
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if (!dissector_try_port(subdissector_table, chdlctype, next_tvb, pinfo, tree)) {
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_add_fstr(pinfo->cinfo, COL_PROTOCOL, "0x%04x", chdlctype);
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call_dissector(data_handle,next_tvb, pinfo, tree);
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}
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}
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static void
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dissect_chdlc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_item *ti;
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proto_tree *fh_tree = NULL;
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guint8 addr;
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guint16 proto;
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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, "N/A");
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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, "N/A");
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "CHDLC");
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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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addr = tvb_get_guint8(tvb, 0);
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proto = tvb_get_ntohs(tvb, 2);
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if (tree) {
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ti = proto_tree_add_item(tree, proto_chdlc, tvb, 0, 4, FALSE);
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fh_tree = proto_item_add_subtree(ti, ett_chdlc);
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proto_tree_add_uint(fh_tree, hf_chdlc_addr, tvb, 0, 1, addr);
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}
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chdlctype(proto, tvb, 4, pinfo, tree, fh_tree, hf_chdlc_proto);
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}
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void
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proto_register_chdlc(void)
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{
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static hf_register_info hf[] = {
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{ &hf_chdlc_addr,
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{ "Address", "chdlc.address", FT_UINT8, BASE_HEX,
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VALS(chdlc_address_vals), 0x0, "", HFILL }},
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{ &hf_chdlc_proto,
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{ "Protocol", "chdlc.protocol", FT_UINT16, BASE_HEX,
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VALS(chdlc_vals), 0x0, "", HFILL }},
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};
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static gint *ett[] = {
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&ett_chdlc,
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};
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proto_chdlc = proto_register_protocol("Cisco HDLC", "CHDLC", "chdlc");
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proto_register_field_array(proto_chdlc, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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/* subdissector code */
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subdissector_table = register_dissector_table("chdlctype",
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"Cisco HDLC frame type", FT_UINT16, BASE_HEX);
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register_dissector("chdlc", dissect_chdlc, proto_chdlc);
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}
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void
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proto_reg_handoff_chdlc(void)
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{
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dissector_handle_t chdlc_handle;
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data_handle = find_dissector("data");
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chdlc_handle = find_dissector("chdlc");
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dissector_add("wtap_encap", WTAP_ENCAP_CHDLC, chdlc_handle);
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}
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#define SLARP_REQUEST 0
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#define SLARP_REPLY 1
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#define SLARP_LINECHECK 2
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static const value_string slarp_ptype_vals[] = {
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{SLARP_REQUEST, "Request"},
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{SLARP_REPLY, "Reply"},
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{SLARP_LINECHECK, "Line keepalive"},
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{0, NULL}
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};
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static void
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dissect_slarp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_item *ti;
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proto_tree *slarp_tree = NULL;
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guint32 code;
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guint32 address;
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guint32 mysequence;
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guint32 yoursequence;
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "SLARP");
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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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code = tvb_get_ntohl(tvb, 0);
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if (tree) {
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ti = proto_tree_add_item(tree, proto_slarp, tvb, 0, 14, FALSE);
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slarp_tree = proto_item_add_subtree(ti, ett_slarp);
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}
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switch (code) {
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case SLARP_REQUEST:
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case SLARP_REPLY:
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if (check_col(pinfo->cinfo, COL_INFO)) {
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tvb_memcpy(tvb, (guint8 *)&address, 4, 4);
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col_add_fstr(pinfo->cinfo, COL_INFO, "%s, from %s, mask %s",
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match_strval(code, slarp_ptype_vals),
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get_hostname(address),
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ip_to_str(tvb_get_ptr(tvb, 8, 4)));
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}
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if (tree) {
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proto_tree_add_uint(slarp_tree, hf_slarp_ptype, tvb, 0, 4, code);
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proto_tree_add_item(slarp_tree, hf_slarp_address, tvb, 4, 4, FALSE);
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proto_tree_add_text(slarp_tree, tvb, 8, 4,
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"Netmask: %s", ip_to_str(tvb_get_ptr(tvb, 8, 4)));
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}
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break;
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case SLARP_LINECHECK:
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mysequence = tvb_get_ntohl(tvb, 4);
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yoursequence = tvb_get_ntohl(tvb, 8);
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if (check_col(pinfo->cinfo, COL_INFO)) {
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col_add_fstr(pinfo->cinfo, COL_INFO,
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"%s, outgoing sequence %u, returned sequence %u",
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match_strval(code, slarp_ptype_vals),
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mysequence, yoursequence);
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}
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if (tree) {
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proto_tree_add_uint(slarp_tree, hf_slarp_ptype, tvb, 0, 4, code);
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proto_tree_add_uint(slarp_tree, hf_slarp_mysequence, tvb, 4, 4,
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mysequence);
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proto_tree_add_uint(slarp_tree, hf_slarp_mysequence, tvb, 8, 4,
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yoursequence);
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}
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break;
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default:
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if (check_col(pinfo->cinfo, COL_INFO))
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col_add_fstr(pinfo->cinfo, COL_INFO, "Unknown packet type 0x%08X", code);
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if (tree) {
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proto_tree_add_uint(slarp_tree, hf_slarp_ptype, tvb, 0, 4, code);
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call_dissector(data_handle, tvb_new_subset(tvb, 4, -1, -1), pinfo,
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slarp_tree);
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}
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break;
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}
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}
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void
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proto_register_slarp(void)
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{
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static hf_register_info hf[] = {
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{ &hf_slarp_ptype,
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{ "Packet type", "slarp.ptype", FT_UINT32, BASE_DEC,
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VALS(slarp_ptype_vals), 0x0, "", HFILL }},
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{ &hf_slarp_address,
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{ "Address", "slarp.address", FT_IPv4, BASE_NONE,
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NULL, 0x0, "", HFILL }},
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/* XXX - need an FT_ for netmasks, which is like FT_IPV4 but doesn't
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get translated to a host name. */
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{ &hf_slarp_mysequence,
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{ "Outgoing sequence number", "slarp.mysequence", FT_UINT32, BASE_DEC,
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NULL, 0x0, "", HFILL }},
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{ &hf_slarp_yoursequence,
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{ "Returned sequence number", "slarp.yoursequence", FT_UINT32, BASE_DEC,
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NULL, 0x0, "", HFILL }},
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};
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static gint *ett[] = {
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&ett_chdlc,
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&ett_slarp,
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};
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proto_slarp = proto_register_protocol("Cisco SLARP", "SLARP", "slarp");
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proto_register_field_array(proto_slarp, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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void
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proto_reg_handoff_slarp(void)
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{
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dissector_handle_t slarp_handle;
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slarp_handle = create_dissector_handle(dissect_slarp, proto_slarp);
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dissector_add("chdlctype", CISCO_SLARP, slarp_handle);
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}
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