2 * Routines for RLM dissection
3 * Copyright 2004, Duncan Sargeant <dunc-ethereal@rcpt.to>
7 * Wireshark - Network traffic analyzer
8 * By Gerald Combs <gerald@wireshark.org>
9 * Copyright 1998 Gerald Combs
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.
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.
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.
27 * RLM is a proprietary Cisco protocol used for centralling managing
28 * many redundant NASes. I don't know much about the format, but you
29 * can read about the feature here:
31 * http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/rlm_123.htm
33 * RLM runs on a UDP port (default 3000) between the MGC and the NAS.
34 * On port N+1 (default 3001), a Q.931/LAPD/UDP connection is maintained.
35 * Both sides use the same local port number for the connection, so source
36 * and dest port are always the same.
38 * In large networks, the links are typically split onto higher ports,
39 * so anything up to 3015 (or higher) could either be RLM or Q.931 traffic,
40 * although always the RLM has the one lower port number for that RLM group.
42 * Multiple RLM groups are possible on a single NAS.
44 * I haven't been able to find the protocol documented, so I've
45 * guessed some of the fields based on the output of debug commands on
59 #include <epan/packet.h>
61 /* Initialize the protocol and registered fields */
62 static int proto_rlm = -1;
64 static int hf_rlm_version = -1;
65 static int hf_rlm_type = -1;
66 static int hf_rlm_unknown = -1;
67 static int hf_rlm_tid = -1;
68 static int hf_rlm_unknown2 = -1;
70 /* Initialize the subtree pointers */
71 static gint ett_rlm = -1;
74 /* RLM definitions - missing some! */
76 #define RLM_START_REQUEST 1
77 #define RLM_START_ACK 2
80 #define RLM_ECHO_REQUEST 5
81 #define RLM_ECHO_REPLY 6
86 Maybe this isn't the best place for it, but RLM goes hand in hand
87 with Q.931 traffic on a higher port.
91 dissect_udp_lapd(tvbuff_t *tvb, packet_info *pinfo _U_ , proto_tree *tree) {
93 if (pinfo->srcport < 3001 || pinfo->srcport > 3015
94 || pinfo->destport < 3001 || pinfo->destport > 3015
95 || pinfo->destport != pinfo->srcport)
98 call_dissector(find_dissector("lapd"), tvb, pinfo, tree);
103 /* Code to actually dissect the packets */
105 dissect_rlm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
108 proto_tree *rlm_tree;
109 guint8 rlm_type, version;
110 const char *type_str = NULL;
112 if (pinfo->srcport < 3000 || pinfo->srcport > 3015
113 || pinfo->destport < 3000 || pinfo->destport > 3015
114 || pinfo->destport != pinfo->srcport)
117 version = tvb_get_guint8(tvb, 0);
118 rlm_type = tvb_get_guint8(tvb, 1);
120 /* we only know about version 2, and I've only seen 8 byte packets */
121 if (tvb_length(tvb) != 8 || version != 2) {
125 if (check_col(pinfo->cinfo, COL_PROTOCOL))
126 col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLM");
129 case RLM_START_REQUEST:
130 type_str = "Start request";
134 type_str = "Start acknowledgement";
137 case RLM_ECHO_REQUEST:
138 type_str = "Echo request";
142 type_str = "Echo reply";
146 type_str = "Unknown type";
150 if (check_col(pinfo->cinfo, COL_INFO))
151 col_set_str(pinfo->cinfo, COL_INFO, type_str);
154 /* proto_tree_add_protocol_format(tree, proto_rlm, tvb, 0,
155 16, "Cisco Session Management"); */
156 ti = proto_tree_add_item(tree, proto_rlm, tvb, 0, 8, FALSE);
157 rlm_tree = proto_item_add_subtree(ti, ett_rlm);
158 ti = proto_tree_add_item(rlm_tree, hf_rlm_version, tvb, 0, 1, FALSE);
159 proto_tree_add_uint_format(rlm_tree, hf_rlm_type, tvb, 1, 1, rlm_type, "Type: %u (%s)", rlm_type, type_str);
160 ti = proto_tree_add_item(rlm_tree, hf_rlm_unknown, tvb, 2, 2, FALSE);
161 ti = proto_tree_add_item(rlm_tree, hf_rlm_tid, tvb, 4, 2, FALSE);
162 ti = proto_tree_add_item(rlm_tree, hf_rlm_unknown2, tvb, 6, 2, FALSE);
169 /* Register the protocol with Ethereal */
171 /* this format is require because a script is used to build the C function
172 that calls all the protocol registration.
176 proto_reg_handoff_rlm(void)
178 heur_dissector_add("udp", dissect_rlm, proto_rlm);
179 heur_dissector_add("udp", dissect_udp_lapd, proto_get_id_by_filter_name("lapd"));
183 proto_register_rlm(void)
186 /* Setup list of header fields See Section 1.6.1 for details*/
187 static hf_register_info hf[] = {
189 { "Version", "rlm.version",
190 FT_UINT8, BASE_DEC, NULL, 0x0,
194 { "Type", "rlm.type",
195 FT_UINT8, BASE_DEC, NULL, 0x0,
199 { "Unknown", "rlm.unknown",
200 FT_UINT16, BASE_HEX, NULL, 0x0,
204 { "Transaction ID", "rlm.tid",
205 FT_UINT16, BASE_DEC, NULL, 0x0,
209 { "Unknown", "rlm.unknown2",
210 FT_UINT16, BASE_HEX, NULL, 0x0,
215 /* Setup protocol subtree array */
216 static gint *ett[] = {
220 /* Register the protocol name and description */
221 proto_rlm = proto_register_protocol("Redundant Link Management Protocol",
224 /* Required function calls to register the header fields and subtrees used */
225 proto_register_field_array(proto_rlm, hf, array_length(hf));
226 proto_register_subtree_array(ett, array_length(ett));