1 /* packet-mrdisc.c 2001 Ronnie Sahlberg <See AUTHORS for email>
2 * Routines for IGMP/MRDISC packet disassembly
4 * $Id: packet-mrdisc.c,v 1.7 2002/02/01 11:01:57 guy Exp $
6 * Ethereal - Network traffic analyzer
7 * By Gerald Combs <gerald@ethereal.com>
8 * Copyright 1998 Gerald Combs
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
34 MRDISC : IGMP Multicast Router DISCovery
35 Defined in draft-ietf-idmr-igmp-mrdisc-06.txt
36 TTL==1 and IP.DST==224.0.0.2 for all packets.
43 #ifdef HAVE_SYS_TYPES_H
44 # include <sys/types.h>
51 #include <epan/packet.h>
52 #include "packet-igmp.h"
53 #include "packet-mrdisc.h"
56 static int proto_mrdisc = -1;
57 static int hf_checksum = -1;
58 static int hf_checksum_bad = -1;
59 static int hf_type = -1;
60 static int hf_advint = -1;
61 static int hf_numopts = -1;
62 static int hf_options = -1;
63 static int hf_option = -1;
64 static int hf_option_len = -1;
65 static int hf_qi = -1;
66 static int hf_rv = -1;
67 static int hf_option_bytes = -1;
69 static int ett_mrdisc = -1;
70 static int ett_options = -1;
72 #define MRDISC_MRA 0x24
73 #define MRDISC_MRS 0x25
74 #define MRDISC_MRT 0x26
75 static const value_string mrdisc_types[] = {
76 {MRDISC_MRA, "Multicast Router Advertisement"},
77 {MRDISC_MRS, "Multicast Router Solicitation"},
78 {MRDISC_MRT, "Multicast Router Termination"},
82 #define MRDISC_QI 0x01
83 #define MRDISC_RV 0x02
84 static const value_string mrdisc_options[] = {
85 {MRDISC_QI, "Query Interval"},
86 {MRDISC_RV, "Robustness Variable"},
92 dissect_mrdisc_mra(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
96 /* Advertising Interval */
97 proto_tree_add_item(parent_tree, hf_advint, tvb, offset, 1, FALSE);
101 igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
104 /* skip unused bytes */
107 /* number of options */
108 num = tvb_get_ntohs(tvb, offset);
109 proto_tree_add_uint(parent_tree, hf_numopts, tvb,
113 /* process any options */
118 int old_offset = offset;
120 item = proto_tree_add_item(parent_tree, hf_options,
121 tvb, offset, -1, FALSE);
122 tree = proto_item_add_subtree(item, ett_options);
124 type = tvb_get_guint8(tvb, offset);
125 proto_tree_add_uint(tree, hf_option, tvb, offset, 1, type);
128 len = tvb_get_guint8(tvb, offset);
129 proto_tree_add_uint(tree, hf_option_len, tvb, offset, 1, len);
135 proto_item_set_text(item,"Option: %s == %d",
136 val_to_str(type, mrdisc_options, "unknown %x"),
137 tvb_get_ntohs(tvb, offset));
140 proto_tree_add_item(tree, hf_qi, tvb, offset, len,
146 proto_item_set_text(item,"Option: %s == %d",
147 val_to_str(type, mrdisc_options, "unknown %x"),
148 tvb_get_ntohs(tvb, offset));
151 proto_tree_add_item(tree, hf_rv, tvb, offset, len,
157 proto_item_set_text(item,"Option: unknown");
160 proto_tree_add_item(tree, hf_option_bytes,
161 tvb, offset, len, FALSE);
165 proto_item_set_len(item, offset-old_offset);
174 dissect_mrdisc_mrst(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
176 /* skip reserved byte */
180 igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
187 /* This function is only called from the IGMP dissector */
189 dissect_mrdisc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
195 if (!proto_is_protocol_enabled(proto_mrdisc)) {
196 /* we are not enabled, skip entire packet to be nice
197 to the igmp layer. (so clicking on IGMP will display the data)
199 return offset+tvb_length_remaining(tvb, offset);
202 item = proto_tree_add_item(parent_tree, proto_mrdisc, tvb, offset, 0, FALSE);
203 tree = proto_item_add_subtree(item, ett_mrdisc);
206 if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
207 col_set_str(pinfo->cinfo, COL_PROTOCOL, "MRDISC");
209 if (check_col(pinfo->cinfo, COL_INFO)) {
210 col_clear(pinfo->cinfo, COL_INFO);
214 type = tvb_get_guint8(tvb, offset);
215 if (check_col(pinfo->cinfo, COL_INFO)) {
216 col_add_fstr(pinfo->cinfo, COL_INFO,
217 "%s",val_to_str(type, mrdisc_types,
218 "Unknown Type:0x%02x"));
221 /* type of command */
222 proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);
227 offset = dissect_mrdisc_mra(tvb, pinfo, tree, offset);
231 /* MRS and MRT packets looks the same */
232 offset = dissect_mrdisc_mrst(tvb, pinfo, tree, offset);
240 proto_register_mrdisc(void)
242 static hf_register_info hf[] = {
244 { "Type", "mrdisc.type", FT_UINT8, BASE_HEX,
245 VALS(mrdisc_types), 0, "MRDISC Packet Type", HFILL }},
248 { "Checksum", "mrdisc.checksum", FT_UINT16, BASE_HEX,
249 NULL, 0, "MRDISC Checksum", HFILL }},
252 { "Bad Checksum", "mrdisc.checksum_bad", FT_BOOLEAN, BASE_NONE,
253 NULL, 0, "Bad MRDISC Checksum", HFILL }},
256 { "Advertising Interval", "mrdisc.adv_int", FT_UINT8, BASE_DEC,
257 NULL, 0, "MRDISC Advertising Interval in seconds", HFILL }},
260 { "Number Of Options", "mrdisc.num_opts", FT_UINT16, BASE_DEC,
261 NULL, 0, "MRDISC Number Of Options", HFILL }},
264 { "Options", "mrdisc.options", FT_NONE, BASE_NONE,
265 NULL, 0, "MRDISC Options", HFILL }},
268 { "Option", "mrdisc.option", FT_UINT8, BASE_DEC,
269 VALS(mrdisc_options), 0, "MRDISC Option Type", HFILL }},
272 { "Length", "mrdisc.opt_len", FT_UINT8, BASE_DEC,
273 NULL, 0, "MRDISC Option Length", HFILL }},
276 { "Query Interval", "mrdisc.query_int", FT_UINT16, BASE_DEC,
277 NULL, 0, "MRDISC Query Interval", HFILL }},
280 { "Robustness Variable", "mrdisc.rob_var", FT_UINT16, BASE_DEC,
281 NULL, 0, "MRDISC Robustness Variable", HFILL }},
284 { "Data", "mrdisc.option_data", FT_BYTES, BASE_NONE,
285 NULL, 0, "MRDISC Unknown Option Data", HFILL }},
288 static gint *ett[] = {
293 proto_mrdisc = proto_register_protocol("Multicast Router DISCovery protocol",
295 proto_register_field_array(proto_mrdisc, hf, array_length(hf));
296 proto_register_subtree_array(ett, array_length(ett));