forked from osmocom/wireshark
228 lines
6.2 KiB
C
228 lines
6.2 KiB
C
/* packet-rlm.c
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* Routines for RLM dissection
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* Copyright 2004, Duncan Sargeant <dunc-ethereal@rcpt.to>
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*
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* $Id$
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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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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/*
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* RLM is a proprietary Cisco protocol used for centralling managing
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* many redundant NASes. I don't know much about the format, but you
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* can read about the feature here:
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*
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* http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/rlm_123.htm
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*
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* RLM runs on a UDP port (default 3000) between the MGC and the NAS.
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* On port N+1 (default 3001), a Q.931/LAPD/UDP connection is maintained.
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* Both sides use the same local port number for the connection, so source
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* and dest port are always the same.
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*
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* In large networks, the links are typically split onto higher ports,
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* so anything up to 3015 (or higher) could either be RLM or Q.931 traffic,
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* although always the RLM has the one lower port number for that RLM group.
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*
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* Multiple RLM groups are possible on a single NAS.
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*
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* I haven't been able to find the protocol documented, so I've
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* guessed some of the fields based on the output of debug commands on
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* cisco NASes.
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*
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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 <string.h>
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#include <glib.h>
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#include <epan/packet.h>
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/* Initialize the protocol and registered fields */
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static int proto_rlm = -1;
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static int hf_rlm_version = -1;
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static int hf_rlm_type = -1;
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static int hf_rlm_unknown = -1;
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static int hf_rlm_tid = -1;
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static int hf_rlm_unknown2 = -1;
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/* Initialize the subtree pointers */
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static gint ett_rlm = -1;
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/* RLM definitions - missing some! */
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#define RLM_START_REQUEST 1
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#define RLM_START_ACK 2
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/* #define ??? 3 */
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/* #define ??? 4 */
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#define RLM_ECHO_REQUEST 5
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#define RLM_ECHO_REPLY 6
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/* #define ??? ?? */
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/*
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Maybe this isn't the best place for it, but RLM goes hand in hand
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with Q.931 traffic on a higher port.
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*/
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static gboolean
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dissect_udp_lapd(tvbuff_t *tvb, packet_info *pinfo _U_ , proto_tree *tree) {
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if (pinfo->srcport < 3001 || pinfo->srcport > 3015
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|| pinfo->destport < 3001 || pinfo->destport > 3015
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|| pinfo->destport != pinfo->srcport)
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return FALSE;
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call_dissector(find_dissector("lapd"), tvb, pinfo, tree);
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return TRUE;
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}
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/* Code to actually dissect the packets */
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static gboolean
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dissect_rlm(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 *rlm_tree;
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guint8 rlm_type, version;
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const char *type_str = NULL;
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if (pinfo->srcport < 3000 || pinfo->srcport > 3015
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|| pinfo->destport < 3000 || pinfo->destport > 3015
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|| pinfo->destport != pinfo->srcport)
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return FALSE;
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version = tvb_get_guint8(tvb, 0);
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rlm_type = tvb_get_guint8(tvb, 1);
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/* we only know about version 2, and I've only seen 8 byte packets */
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if (tvb_length(tvb) != 8 || version != 2) {
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return FALSE;
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}
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLM");
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switch (rlm_type) {
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case RLM_START_REQUEST:
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type_str = "Start request";
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break;;
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case RLM_START_ACK:
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type_str = "Start acknowledgement";
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break;;
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case RLM_ECHO_REQUEST:
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type_str = "Echo request";
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break;;
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case RLM_ECHO_REPLY:
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type_str = "Echo reply";
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break;;
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default:
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type_str = "Unknown type";
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break;;
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}
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if (check_col(pinfo->cinfo, COL_INFO))
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col_set_str(pinfo->cinfo, COL_INFO, type_str);
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if (tree) {
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/* proto_tree_add_protocol_format(tree, proto_rlm, tvb, 0,
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16, "Cisco Session Management"); */
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ti = proto_tree_add_item(tree, proto_rlm, tvb, 0, 8, FALSE);
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rlm_tree = proto_item_add_subtree(ti, ett_rlm);
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ti = proto_tree_add_item(rlm_tree, hf_rlm_version, tvb, 0, 1, FALSE);
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proto_tree_add_uint_format(rlm_tree, hf_rlm_type, tvb, 1, 1, rlm_type, "Type: %u (%s)", rlm_type, type_str);
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ti = proto_tree_add_item(rlm_tree, hf_rlm_unknown, tvb, 2, 2, FALSE);
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ti = proto_tree_add_item(rlm_tree, hf_rlm_tid, tvb, 4, 2, FALSE);
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ti = proto_tree_add_item(rlm_tree, hf_rlm_unknown2, tvb, 6, 2, FALSE);
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}
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return TRUE;
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}
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/* Register the protocol with Wireshark */
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/* this format is require because a script is used to build the C function
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that calls all the protocol registration.
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*/
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void
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proto_reg_handoff_rlm(void)
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{
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heur_dissector_add("udp", dissect_rlm, proto_rlm);
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heur_dissector_add("udp", dissect_udp_lapd, proto_get_id_by_filter_name("lapd"));
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}
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void
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proto_register_rlm(void)
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{
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/* Setup list of header fields See Section 1.6.1 for details*/
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static hf_register_info hf[] = {
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{ &hf_rlm_version,
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{ "Version", "rlm.version",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"", HFILL }
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},
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{ &hf_rlm_type,
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{ "Type", "rlm.type",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"", HFILL }
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},
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{ &hf_rlm_unknown,
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{ "Unknown", "rlm.unknown",
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FT_UINT16, BASE_HEX, NULL, 0x0,
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"", HFILL }
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},
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{ &hf_rlm_tid,
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{ "Transaction ID", "rlm.tid",
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FT_UINT16, BASE_DEC, NULL, 0x0,
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"", HFILL }
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},
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{ &hf_rlm_unknown2,
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{ "Unknown", "rlm.unknown2",
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FT_UINT16, BASE_HEX, NULL, 0x0,
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"", HFILL }
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},
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};
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/* Setup protocol subtree array */
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static gint *ett[] = {
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&ett_rlm,
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};
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/* Register the protocol name and description */
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proto_rlm = proto_register_protocol("Redundant Link Management Protocol",
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"RLM", "rlm");
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/* Required function calls to register the header fields and subtrees used */
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proto_register_field_array(proto_rlm, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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