2 * Routines for M2TP User Adaptation Layer dissection
3 * M2TP - MTP2 Transparent Proxy - is a Radisys proprietary
4 * protocol based on the IETF SIGTRAN standard
6 * Copyright 2001, Heinz Prantner <heinz.prantner[AT]radisys.com>
8 * $Id: packet-m2tp.c,v 1.3 2002/01/24 09:20:49 guy Exp $
10 * Ethereal - Network traffic analyzer
11 * By Gerald Combs <gerald@ethereal.com>
12 * Copyright 1998 Gerald Combs
14 * Copied from packet-m3ua.c
15 * Thanks to Michael Tuexen for his valuable improvements
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version 2
20 * of the License, or (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
38 #include <epan/packet.h>
40 #define SCTP_PORT_M2TP 9908 /* unassigned port number (not assigned by IANA) */
41 #define M2TP_PAYLOAD_PROTO_ID 99 /* s-link */
43 #define VERSION_LENGTH 1
44 #define RESERVED_LENGTH 1
45 #define MESSAGE_CLASS_LENGTH 1
46 #define MESSAGE_TYPE_LENGTH 1
47 #define MESSAGE_LENGTH_LENGTH 4
48 #define COMMON_HEADER_LENGTH (VERSION_LENGTH + RESERVED_LENGTH + MESSAGE_CLASS_LENGTH + \
49 MESSAGE_TYPE_LENGTH + MESSAGE_LENGTH_LENGTH)
51 #define VERSION_OFFSET 0
52 #define RESERVED_OFFSET (VERSION_OFFSET + VERSION_LENGTH)
53 #define MESSAGE_CLASS_OFFSET (RESERVED_OFFSET + RESERVED_LENGTH)
54 #define MESSAGE_TYPE_OFFSET (MESSAGE_CLASS_OFFSET + MESSAGE_CLASS_LENGTH)
55 #define MESSAGE_LENGTH_OFFSET (MESSAGE_TYPE_OFFSET + MESSAGE_TYPE_LENGTH)
57 #define PARAMETER_TAG_LENGTH 2
58 #define PARAMETER_LENGTH_LENGTH 2
59 #define PARAMETER_HEADER_LENGTH (PARAMETER_TAG_LENGTH + PARAMETER_LENGTH_LENGTH)
61 #define PARAMETER_TAG_OFFSET 0
62 #define PARAMETER_LENGTH_OFFSET (PARAMETER_TAG_OFFSET + PARAMETER_TAG_LENGTH)
63 #define PARAMETER_VALUE_OFFSET (PARAMETER_LENGTH_OFFSET + PARAMETER_LENGTH_LENGTH)
64 #define PARAMETER_HEADER_OFFSET PARAMETER_TAG_OFFSET
66 #define INTERFACE_IDENTIFIER_PARAMETER_TAG 1
67 #define MASTER_SLAVE_INDICATOR_PARAMETER_TAG 2
68 #define M2TP_USER_IDENTIFIER_PARAMETER_TAG 3
69 #define INFO_PARAMETER_TAG 4
70 #define DIAGNOSTIC_INFORMATION_PARAMETER_TAG 7
71 #define HEARTBEAT_DATA_PARAMETER_TAG 9
72 #define REASON_PARAMETER_TAG 10
73 #define ERROR_CODE_PARAMETER_TAG 12
74 #define PROTOCOL_DATA_PARAMETER_TAG 13
77 static const value_string m2tp_parameter_tag_values[] = {
78 { INTERFACE_IDENTIFIER_PARAMETER_TAG, "Interface Identifier" },
79 { MASTER_SLAVE_INDICATOR_PARAMETER_TAG, "Master Slave Indicator" },
80 { M2TP_USER_IDENTIFIER_PARAMETER_TAG, "M2tp User Identifier" },
81 { INFO_PARAMETER_TAG, "Info" },
82 { DIAGNOSTIC_INFORMATION_PARAMETER_TAG, "Diagnostic Information" },
83 { HEARTBEAT_DATA_PARAMETER_TAG, "Heartbeat Data" },
84 { REASON_PARAMETER_TAG, "Reason" },
85 { ERROR_CODE_PARAMETER_TAG, "Error Code" },
86 { PROTOCOL_DATA_PARAMETER_TAG, "Protocol Data" },
89 #define PROTOCOL_VERSION_RELEASE_1 1
91 static const value_string m2tp_protocol_version_values[] = {
92 { PROTOCOL_VERSION_RELEASE_1, "Release 1" },
95 #define MESSAGE_CLASS_MGMT_MESSAGE 0
96 #define MESSAGE_CLASS_SGSM_MESSAGE 3
97 #define MESSAGE_CLASS_MAUP_MESSAGE 6
98 #define MESSAGE_CLASS_DATA_MESSAGE 255
100 static const value_string m2tp_message_class_values[] = {
101 { MESSAGE_CLASS_MGMT_MESSAGE, "Management Messages" },
102 { MESSAGE_CLASS_SGSM_MESSAGE, "SG State Maintenance Messages" },
103 { MESSAGE_CLASS_MAUP_MESSAGE, "MTP2 User Adaptation Messages" },
104 { MESSAGE_CLASS_DATA_MESSAGE, "User Data Messages" },
107 /* management messages */
108 #define MESSAGE_TYPE_ERR 0
110 /* sg state maintenance messages */
111 #define MESSAGE_TYPE_UP 1
112 #define MESSAGE_TYPE_DOWN 2
113 #define MESSAGE_TYPE_BEAT 3
114 #define MESSAGE_TYPE_UP_ACK 4
115 #define MESSAGE_TYPE_DOWN_ACK 5
116 #define MESSAGE_TYPE_BEAT_ACK 6
118 /* mtp2 user message */
119 #define MESSAGE_TYPE_DATA 1
122 static const value_string m2tp_message_class_type_values[] = {
123 { MESSAGE_CLASS_MGMT_MESSAGE * 256 + MESSAGE_TYPE_ERR, "Error (ERR)" },
124 { MESSAGE_CLASS_DATA_MESSAGE * 256 + MESSAGE_TYPE_DATA, "Payload data (DATA)" },
125 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP, "ASP up (UP)" },
126 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN, "ASP down (DOWN)" },
127 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT, "Heartbeat (BEAT)" },
128 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP_ACK, "ASP up ack (UP ACK)" },
129 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN_ACK, "ASP down ack (DOWN ACK)" },
130 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT_ACK, "Heartbeat ack (BEAT ACK)" },
133 static const value_string m2tp_message_class_type_acro_values[] = {
134 { MESSAGE_CLASS_MGMT_MESSAGE * 256 + MESSAGE_TYPE_ERR, "ERR" },
135 { MESSAGE_CLASS_DATA_MESSAGE * 256 + MESSAGE_TYPE_DATA, "DATA" },
136 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP, "ASP_UP" },
137 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN, "ASP_DOWN" },
138 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT, "BEAT" },
139 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP_ACK, "ASP_UP_ACK" },
140 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN_ACK, "ASP_DOWN_ACK" },
141 { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT_ACK, "BEAT_ACK" },
146 #define HEARTBEAT_PERIOD_OFFSET PARAMETER_VALUE_OFFSET
148 #define INTERFACE_IDENTIFIER_LENGTH 4
149 #define INTERFACE_IDENTIFIER_OFFSET PARAMETER_VALUE_OFFSET
151 #define M2TP_USER_LENGTH 4
152 #define M2TP_USER_OFFSET PARAMETER_VALUE_OFFSET
154 #define PROTOCOL_DATA_OFFSET PARAMETER_VALUE_OFFSET
156 #define MASTER_SLAVE_LENGTH 4
157 #define MASTER_SLAVE_OFFSET PARAMETER_VALUE_OFFSET
159 #define REASON_LENGTH 4
160 #define REASON_OFFSET PARAMETER_VALUE_OFFSET
162 #define HEART_BEAT_DATA_OFFSET PARAMETER_VALUE_OFFSET
164 #define ERROR_CODE_LENGTH 4
165 #define ERROR_CODE_OFFSET PARAMETER_VALUE_OFFSET
167 #define INFO_STRING_OFFSET PARAMETER_VALUE_OFFSET
169 #define BSN_OFFSET PARAMETER_VALUE_OFFSET
170 #define FSN_OFFSET PARAMETER_VALUE_OFFSET+1
172 #define M2TP_USER_MTP2 1
173 #define M2TP_USER_Q921 2
174 #define M2TP_USER_FRAME_RELAY 3
176 static const value_string m2tp_user_identifier_values[] = {
177 { M2TP_USER_MTP2, "MTP2" },
178 { M2TP_USER_Q921, "Q.921" },
179 { M2TP_USER_FRAME_RELAY, "Frame Relay" },
182 #define M2TP_MODE_MASTER 1
183 #define M2TP_MODE_SLAVE 2
185 static const value_string m2tp_mode_values[] = {
186 { M2TP_MODE_MASTER, "Master" },
187 { M2TP_MODE_SLAVE, "Slave" },
190 #define M2TP_ERROR_CODE_INVALID_VERSION 1
191 #define M2TP_ERROR_CODE_INVALID_INTERFACE_IDENTIFIER 2
192 #define M2TP_ERROR_CODE_INVALID_ADAPTATION_LAYER_IDENTIFIER 3
193 #define M2TP_ERROR_CODE_INVALID_MESSAGE_TYPE 4
194 #define M2TP_ERROR_CODE_INVALID_TRAFFIC_HANDLING_MODE 5
195 #define M2TP_ERROR_CODE_UNEXPECTED_MESSAGE 6
196 #define M2TP_ERROR_CODE_PROTOCOL_ERROR 7
197 #define M2TP_ERROR_CODE_INVALID_STREAM_IDENTIFIER 8
198 #define M2TP_ERROR_CODE_INCOMPATIBLE_MASTER_SLAVE_CONFIGURATION 9
200 static const value_string m2tp_error_code_values[] = {
201 { M2TP_ERROR_CODE_INVALID_VERSION, "Invalid Version" },
202 { M2TP_ERROR_CODE_INVALID_INTERFACE_IDENTIFIER, "Invalid Interface Identifier" },
203 { M2TP_ERROR_CODE_INVALID_ADAPTATION_LAYER_IDENTIFIER, "Invalid Adaptation Layer Identifier" },
204 { M2TP_ERROR_CODE_INVALID_MESSAGE_TYPE, "Invalid Message Type" },
205 { M2TP_ERROR_CODE_INVALID_TRAFFIC_HANDLING_MODE, "Invalid Traffic Handling Mode" },
206 { M2TP_ERROR_CODE_UNEXPECTED_MESSAGE, "Unexpected Message" },
207 { M2TP_ERROR_CODE_PROTOCOL_ERROR, "Protocol Error" },
208 { M2TP_ERROR_CODE_INVALID_STREAM_IDENTIFIER, "Invalid Stream Identified" },
209 { M2TP_ERROR_CODE_INCOMPATIBLE_MASTER_SLAVE_CONFIGURATION,"Incompatible Master Slave Configuration" },
212 #define MANAGEMENT_ORDER_REASON_CODE 1
213 #define MTP_RELEASE_REASON_CODE 2
215 static const value_string m2tp_reason_code_values[] = {
216 { MANAGEMENT_ORDER_REASON_CODE, "Management Order" },
217 { MTP_RELEASE_REASON_CODE, "MTP Release" },
221 /* Initialize the protocol and registered fields */
222 static int proto_m2tp = -1;
223 static int hf_m2tp_version = -1;
224 static int hf_m2tp_reserved = -1;
225 static int hf_m2tp_message_class = -1;
226 static int hf_m2tp_message_type = -1;
227 static int hf_m2tp_message_length = -1;
228 static int hf_m2tp_parameter_tag = -1;
229 static int hf_m2tp_parameter_length = -1;
230 static int hf_m2tp_parameter_value = -1;
231 static int hf_m2tp_parameter_padding = -1;
232 static int hf_m2tp_interface_identifier = -1;
233 static int hf_m2tp_user = -1;
234 static int hf_m2tp_master_slave = -1;
235 static int hf_m2tp_info_string = -1;
236 static int hf_m2tp_heartbeat_data = -1;
237 static int hf_m2tp_diagnostic_info = -1;
238 static int hf_m2tp_error_code = -1;
239 static int hf_m2tp_reason = -1;
241 /* Initialize the subtree pointers */
242 static gint ett_m2tp = -1;
243 static gint ett_m2tp_parameter = -1;
245 static dissector_handle_t mtp2_handle;
246 static int mtp2_proto_id;
249 nr_of_padding_bytes (guint length)
253 remainder = length % 4;
258 return 4 - remainder;
263 dissect_m2tp_common_header(tvbuff_t *common_header_tvb, packet_info *pinfo, proto_tree *m2tp_tree)
265 guint8 version, reserved, message_class, message_type;
266 guint32 message_length;
268 /* Extract the common header */
269 version = tvb_get_guint8(common_header_tvb, VERSION_OFFSET);
270 reserved = tvb_get_guint8(common_header_tvb, RESERVED_OFFSET);
271 message_class = tvb_get_guint8(common_header_tvb, MESSAGE_CLASS_OFFSET);
272 message_type = tvb_get_guint8(common_header_tvb, MESSAGE_TYPE_OFFSET);
273 message_length = tvb_get_ntohl (common_header_tvb, MESSAGE_LENGTH_OFFSET);
275 if ((check_col(pinfo->cinfo, COL_INFO)) && (message_class != MESSAGE_CLASS_DATA_MESSAGE)){
276 col_append_str(pinfo->cinfo, COL_INFO,
277 val_to_str(message_class * 256 + message_type, m2tp_message_class_type_acro_values, "reserved"));
278 col_append_str(pinfo->cinfo, COL_INFO, " ");
282 /* add the components of the common header to the protocol tree */
283 proto_tree_add_uint(m2tp_tree, hf_m2tp_version, common_header_tvb, VERSION_OFFSET, VERSION_LENGTH, version);
284 proto_tree_add_uint(m2tp_tree, hf_m2tp_reserved, common_header_tvb, RESERVED_OFFSET, RESERVED_LENGTH, reserved);
285 proto_tree_add_uint(m2tp_tree, hf_m2tp_message_class, common_header_tvb, MESSAGE_CLASS_OFFSET, MESSAGE_CLASS_LENGTH, message_class);
286 proto_tree_add_uint_format(m2tp_tree, hf_m2tp_message_type,
287 common_header_tvb, MESSAGE_TYPE_OFFSET, MESSAGE_TYPE_LENGTH,
288 message_type, "Message type: %u (%s)",
289 message_type, val_to_str(message_class * 256 + message_type, m2tp_message_class_type_values, "reserved"));
290 proto_tree_add_uint(m2tp_tree, hf_m2tp_message_length, common_header_tvb, MESSAGE_LENGTH_OFFSET, MESSAGE_LENGTH_LENGTH, message_length);
294 /* Interface Identifier */
296 dissect_m2tp_interface_identifier_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
298 guint32 parameter_value;
300 if (parameter_tree) {
301 parameter_value = tvb_get_ntohl(parameter_tvb, PARAMETER_VALUE_OFFSET);
302 proto_tree_add_uint(parameter_tree, hf_m2tp_interface_identifier, parameter_tvb, INTERFACE_IDENTIFIER_OFFSET, INTERFACE_IDENTIFIER_LENGTH, parameter_value);
303 proto_item_set_text(parameter_item, "Interface Identifier (%u)", parameter_value);
307 /* Master Slave Indicator */
309 dissect_m2tp_master_slave_parameter (tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
311 guint32 parameter_value;
313 if (parameter_tree) {
314 parameter_value = tvb_get_ntohl(parameter_tvb, PARAMETER_VALUE_OFFSET);
315 proto_tree_add_uint(parameter_tree, hf_m2tp_master_slave, parameter_tvb, MASTER_SLAVE_OFFSET, MASTER_SLAVE_LENGTH, parameter_value);
316 proto_item_set_text(parameter_item, "Master Slave Indicator (%s)", val_to_str(parameter_value, m2tp_mode_values, "unknown"));
320 /* M2tp User Identifier */
322 dissect_m2tp_user_identifier_parameter (tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
324 guint32 parameter_value;
326 if (parameter_tree) {
327 parameter_value = tvb_get_ntohl(parameter_tvb, PARAMETER_VALUE_OFFSET);
328 proto_tree_add_uint(parameter_tree, hf_m2tp_user, parameter_tvb, M2TP_USER_OFFSET, M2TP_USER_LENGTH, parameter_value);
329 proto_item_set_text(parameter_item, "M2TP User Identifier (%u)", parameter_value);
335 dissect_m2tp_info_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
337 guint16 length, info_string_length;
340 if (parameter_tree) {
341 length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET);
342 info_string_length = length - PARAMETER_HEADER_LENGTH;
343 info_string = (char *)tvb_get_ptr(parameter_tvb, INFO_STRING_OFFSET, info_string_length);
344 proto_tree_add_string(parameter_tree, hf_m2tp_info_string, parameter_tvb, INFO_STRING_OFFSET, info_string_length, info_string);
345 proto_item_set_text(parameter_item, "Info String (%.*s)", info_string_length, info_string);
349 /* Diagnostic Information */
351 dissect_m2tp_diagnostic_information_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
353 guint16 length, diagnostic_info_length;
355 if (parameter_tree) {
356 length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET);
357 diagnostic_info_length = length - PARAMETER_HEADER_LENGTH;
358 proto_tree_add_bytes(parameter_tree, hf_m2tp_diagnostic_info, parameter_tvb, PARAMETER_VALUE_OFFSET, diagnostic_info_length,
359 tvb_get_ptr(parameter_tvb, PARAMETER_VALUE_OFFSET, diagnostic_info_length));
360 proto_item_set_text(parameter_item, "Diagnostic information (%u byte%s)", diagnostic_info_length, plurality(diagnostic_info_length, "", "s"));
366 dissect_m2tp_heartbeat_data_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
368 guint16 length, heartbeat_data_length;
370 if (parameter_tree) {
371 length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET);
372 heartbeat_data_length = length - PARAMETER_HEADER_LENGTH;
373 proto_tree_add_bytes(parameter_tree, hf_m2tp_heartbeat_data, parameter_tvb, PARAMETER_VALUE_OFFSET, heartbeat_data_length,
374 tvb_get_ptr(parameter_tvb, PARAMETER_VALUE_OFFSET, heartbeat_data_length));
375 proto_item_set_text(parameter_item, "Heartbeat data (%u byte%s)", heartbeat_data_length, plurality(heartbeat_data_length, "", "s"));
379 /* Reason Parameter */
381 dissect_m2tp_reason_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
385 if (parameter_tree) {
386 reason = tvb_get_ntohl(parameter_tvb, REASON_OFFSET);
387 proto_tree_add_uint(parameter_tree, hf_m2tp_reason, parameter_tvb, REASON_OFFSET, REASON_LENGTH, reason);
388 proto_item_set_text(parameter_item, "Reason parameter (%s)", val_to_str(reason, m2tp_reason_code_values, "unknown"));
394 dissect_m2tp_error_code_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
398 if (parameter_tree) {
399 error_code = tvb_get_ntohl(parameter_tvb, ERROR_CODE_OFFSET);
400 proto_tree_add_uint(parameter_tree, hf_m2tp_error_code, parameter_tvb, ERROR_CODE_OFFSET, ERROR_CODE_LENGTH, error_code);
401 proto_item_set_text(parameter_item, "Error code parameter (%s)", val_to_str(error_code, m2tp_error_code_values, "unknown"));
407 dissect_m2tp_protocol_data_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item, packet_info *pinfo, proto_item *m2tp_item, proto_tree *tree)
409 guint16 length, protocol_data_length, padding_length;
412 length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET);
413 padding_length = nr_of_padding_bytes(length);
414 protocol_data_length = length - PARAMETER_HEADER_LENGTH;
416 mtp2_tvb = tvb_new_subset(parameter_tvb, PARAMETER_VALUE_OFFSET, protocol_data_length, protocol_data_length);
417 call_dissector(mtp2_handle, mtp2_tvb, pinfo, tree);
419 if ((check_col(pinfo->cinfo, COL_INFO)) && (!proto_is_protocol_enabled(mtp2_proto_id)))
420 col_append_str(pinfo->cinfo, COL_INFO, "DATA");
422 if (parameter_tree) {
423 proto_item_set_text(parameter_item, "Protocol data (SS7 message)");
424 proto_item_set_len(parameter_item, proto_item_get_len(parameter_item) - protocol_data_length - padding_length);
425 proto_item_set_len(m2tp_item, proto_item_get_len(m2tp_item) - protocol_data_length - padding_length);
430 /* Unknown Parameter */
432 dissect_m2tp_unknown_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item)
434 guint16 tag, length, parameter_value_length;
436 if (parameter_tree) {
437 tag = tvb_get_ntohs(parameter_tvb, PARAMETER_TAG_OFFSET);
438 length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET);
440 parameter_value_length = length - PARAMETER_HEADER_LENGTH;
441 proto_tree_add_bytes(parameter_tree, hf_m2tp_parameter_value,
442 parameter_tvb, PARAMETER_VALUE_OFFSET, parameter_value_length,
443 tvb_get_ptr(parameter_tvb, PARAMETER_VALUE_OFFSET, parameter_value_length));
445 proto_item_set_text(parameter_item, "Parameter with tag %u and %u byte%s value", tag, parameter_value_length, plurality(parameter_value_length, "", "s"));
451 dissect_m2tp_parameter(tvbuff_t *parameter_tvb, packet_info *pinfo, proto_tree *m2tp_tree, proto_item *m2tp_item, proto_tree *tree)
453 guint16 tag, length, padding_length, total_length;
454 proto_item *parameter_item = NULL;
455 proto_tree *parameter_tree = NULL;
457 /* extract tag and length from the parameter */
458 tag = tvb_get_ntohs(parameter_tvb, PARAMETER_TAG_OFFSET);
459 length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET);
461 /* calculate padding and total length */
462 padding_length = nr_of_padding_bytes(length);
463 total_length = length + padding_length;
466 /* create proto_tree stuff */
467 parameter_item = proto_tree_add_text(m2tp_tree, parameter_tvb, PARAMETER_HEADER_OFFSET, total_length, "Incomplete parameter");
468 parameter_tree = proto_item_add_subtree(parameter_item, ett_m2tp_parameter);
470 /* add tag and length to the m2tp tree */
471 proto_tree_add_uint(parameter_tree, hf_m2tp_parameter_tag, parameter_tvb, PARAMETER_TAG_OFFSET, PARAMETER_TAG_LENGTH, tag);
472 proto_tree_add_uint(parameter_tree, hf_m2tp_parameter_length, parameter_tvb, PARAMETER_LENGTH_OFFSET, PARAMETER_LENGTH_LENGTH, length);
476 case INTERFACE_IDENTIFIER_PARAMETER_TAG:
477 dissect_m2tp_interface_identifier_parameter(parameter_tvb, parameter_tree, parameter_item);
479 case MASTER_SLAVE_INDICATOR_PARAMETER_TAG:
480 dissect_m2tp_master_slave_parameter(parameter_tvb, parameter_tree, parameter_item);
482 case M2TP_USER_IDENTIFIER_PARAMETER_TAG:
483 dissect_m2tp_user_identifier_parameter(parameter_tvb, parameter_tree, parameter_item);
485 case INFO_PARAMETER_TAG:
486 dissect_m2tp_info_parameter(parameter_tvb, parameter_tree, parameter_item);
488 case DIAGNOSTIC_INFORMATION_PARAMETER_TAG:
489 dissect_m2tp_diagnostic_information_parameter(parameter_tvb, parameter_tree, parameter_item);
491 case HEARTBEAT_DATA_PARAMETER_TAG:
492 dissect_m2tp_heartbeat_data_parameter(parameter_tvb, parameter_tree, parameter_item);
494 case REASON_PARAMETER_TAG:
495 dissect_m2tp_reason_parameter(parameter_tvb, parameter_tree, parameter_item);
497 case ERROR_CODE_PARAMETER_TAG:
498 dissect_m2tp_error_code_parameter(parameter_tvb, parameter_tree, parameter_item);
500 case PROTOCOL_DATA_PARAMETER_TAG:
501 dissect_m2tp_protocol_data_parameter(parameter_tvb, parameter_tree, parameter_item, pinfo, m2tp_item, tree);
504 dissect_m2tp_unknown_parameter(parameter_tvb, parameter_tree, parameter_item);
508 if ((parameter_tree) && (padding_length > 0))
509 proto_tree_add_bytes(parameter_tree, hf_m2tp_parameter_padding,
510 parameter_tvb, PARAMETER_HEADER_OFFSET + length, padding_length,
511 tvb_get_ptr(parameter_tvb, PARAMETER_HEADER_OFFSET + length, padding_length));
516 dissect_m2tp_message(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2tp_item, proto_tree *m2tp_tree, proto_tree *tree)
518 gint offset, length, padding_length, total_length;
519 tvbuff_t *common_header_tvb, *parameter_tvb;
523 /* extract and process the common header */
524 common_header_tvb = tvb_new_subset(message_tvb, offset, COMMON_HEADER_LENGTH, COMMON_HEADER_LENGTH);
525 dissect_m2tp_common_header(common_header_tvb, pinfo, m2tp_tree);
526 offset += COMMON_HEADER_LENGTH;
528 /* extract zero or more parameters and process them individually */
529 while(tvb_reported_length_remaining(message_tvb, offset)) {
530 length = tvb_get_ntohs(message_tvb, offset + PARAMETER_LENGTH_OFFSET);
531 padding_length = nr_of_padding_bytes(length);
532 total_length = length + padding_length;
533 /* create a tvb for the parameter including the padding bytes */
534 parameter_tvb = tvb_new_subset(message_tvb, offset, total_length, total_length);
535 dissect_m2tp_parameter(parameter_tvb, pinfo, m2tp_tree, m2tp_item, tree);
536 /* get rid of the handled parameter */
537 offset += total_length;
543 dissect_m2tp(tvbuff_t *message_tvb, packet_info *pinfo, proto_tree *tree)
545 proto_item *m2tp_item;
546 proto_tree *m2tp_tree;
548 /* make entry in the Protocol column on summary display */
549 if (check_col(pinfo->cinfo, COL_PROTOCOL))
550 col_set_str(pinfo->cinfo, COL_PROTOCOL, "M2TP");
552 /* In the interest of speed, if "tree" is NULL, don't do any work not
553 necessary to generate protocol tree items. */
555 /* create the m2tp protocol tree */
556 m2tp_item = proto_tree_add_item(tree, proto_m2tp, message_tvb, 0, -1, FALSE);
557 m2tp_tree = proto_item_add_subtree(m2tp_item, ett_m2tp);
562 /* dissect the message */
563 dissect_m2tp_message(message_tvb, pinfo, m2tp_item, m2tp_tree, tree);
566 /* Register the protocol with Ethereal */
568 proto_register_m2tp(void)
571 /* Setup list of header fields */
572 static hf_register_info hf[] = {
574 { "Version", "m2tp.version",
575 FT_UINT8, BASE_DEC, VALS(m2tp_protocol_version_values), 0x0,
579 { "Reserved", "m2tp.reserved",
580 FT_UINT8, BASE_HEX, NULL, 0x0,
583 { &hf_m2tp_message_class,
584 { "Message class", "m2tp.message_class",
585 FT_UINT8, BASE_DEC, VALS(m2tp_message_class_values), 0x0,
588 { &hf_m2tp_message_type,
589 { "Message Type", "m2tp.message_type",
590 FT_UINT8, BASE_DEC, NULL, 0x0,
593 { &hf_m2tp_message_length,
594 { "Message length", "m2tp.message_length",
595 FT_UINT32, BASE_DEC, NULL, 0x0,
598 { &hf_m2tp_parameter_tag,
599 { "Parameter Tag", "m2tp.parameter_tag",
600 FT_UINT16, BASE_DEC, VALS(m2tp_parameter_tag_values), 0x0,
603 { &hf_m2tp_parameter_length,
604 { "Parameter length", "m2tp.parameter_length",
605 FT_UINT16, BASE_DEC, NULL, 0x0,
608 { &hf_m2tp_parameter_value,
609 { "Parameter Value", "m2tp.parameter_value",
610 FT_BYTES, BASE_NONE, NULL, 0x0,
613 { &hf_m2tp_parameter_padding,
614 { "Padding", "m2tp.parameter_padding",
615 FT_BYTES, BASE_NONE, NULL, 0x0,
618 { &hf_m2tp_interface_identifier,
619 { "Interface Identifier", "m2tp.interface_identifier",
620 FT_UINT32, BASE_DEC, NULL, 0x0,
624 { "M2tp User Identifier", "m2tp.user_identifier",
625 FT_UINT32, BASE_DEC, VALS(m2tp_user_identifier_values), 0x0,
628 { &hf_m2tp_master_slave,
629 { "Master Slave Indicator", "m2tp.master_slave",
630 FT_UINT32, BASE_DEC, VALS(m2tp_mode_values), 0x0,
633 { &hf_m2tp_info_string,
634 { "Info string", "m2tp.info_string",
635 FT_STRING, BASE_DEC, NULL, 0x0,
638 { &hf_m2tp_diagnostic_info,
639 { "Diagnostic information", "m2tp.diagnostic_info",
640 FT_BYTES, BASE_NONE, NULL, 0x0,
643 { &hf_m2tp_heartbeat_data,
644 { "Heartbeat data", "m2tp.heartbeat_data",
645 FT_BYTES, BASE_NONE, NULL, 0x0,
648 { &hf_m2tp_error_code,
649 { "Error code", "m2tp.error_code",
650 FT_UINT32, BASE_DEC, VALS(m2tp_error_code_values), 0x0,
654 { "Reason", "m2tp.reason",
655 FT_UINT32, BASE_DEC, NULL, 0x0,
660 /* Setup protocol subtree array */
661 static gint *ett[] = {
666 /* Register the protocol name and description */
667 proto_m2tp = proto_register_protocol("MTP 2 Transparent Proxy", "M2TP", "m2tp");
669 /* Required function calls to register the header fields and subtrees used */
670 proto_register_field_array(proto_m2tp, hf, array_length(hf));
671 proto_register_subtree_array(ett, array_length(ett));
675 proto_reg_handoff_m2tp(void)
677 dissector_handle_t m2tp_handle;
678 mtp2_handle = find_dissector("mtp2");
679 mtp2_proto_id = proto_get_id_by_filter_name("mtp2");
680 m2tp_handle = create_dissector_handle(dissect_m2tp, proto_m2tp);
681 dissector_add("sctp.ppi", M2TP_PAYLOAD_PROTO_ID, m2tp_handle);
682 dissector_add("sctp.port", SCTP_PORT_M2TP, m2tp_handle);