/* packet-m2tp.c * Routines for M2TP User Adaptation Layer dissection * M2TP - MTP2 Transparent Proxy - is a Radisys proprietary * protocol based on the IETF SIGTRAN standard * * Copyright 2001, Heinz Prantner * * $Id: packet-m2tp.c,v 1.4 2002/08/28 21:00:20 jmayer Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * Copied from packet-m3ua.c * Thanks to Michael Tuexen for his valuable improvements * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #define SCTP_PORT_M2TP 9908 /* unassigned port number (not assigned by IANA) */ #define M2TP_PAYLOAD_PROTO_ID 99 /* s-link */ #define VERSION_LENGTH 1 #define RESERVED_LENGTH 1 #define MESSAGE_CLASS_LENGTH 1 #define MESSAGE_TYPE_LENGTH 1 #define MESSAGE_LENGTH_LENGTH 4 #define COMMON_HEADER_LENGTH (VERSION_LENGTH + RESERVED_LENGTH + MESSAGE_CLASS_LENGTH + \ MESSAGE_TYPE_LENGTH + MESSAGE_LENGTH_LENGTH) #define VERSION_OFFSET 0 #define RESERVED_OFFSET (VERSION_OFFSET + VERSION_LENGTH) #define MESSAGE_CLASS_OFFSET (RESERVED_OFFSET + RESERVED_LENGTH) #define MESSAGE_TYPE_OFFSET (MESSAGE_CLASS_OFFSET + MESSAGE_CLASS_LENGTH) #define MESSAGE_LENGTH_OFFSET (MESSAGE_TYPE_OFFSET + MESSAGE_TYPE_LENGTH) #define PARAMETER_TAG_LENGTH 2 #define PARAMETER_LENGTH_LENGTH 2 #define PARAMETER_HEADER_LENGTH (PARAMETER_TAG_LENGTH + PARAMETER_LENGTH_LENGTH) #define PARAMETER_TAG_OFFSET 0 #define PARAMETER_LENGTH_OFFSET (PARAMETER_TAG_OFFSET + PARAMETER_TAG_LENGTH) #define PARAMETER_VALUE_OFFSET (PARAMETER_LENGTH_OFFSET + PARAMETER_LENGTH_LENGTH) #define PARAMETER_HEADER_OFFSET PARAMETER_TAG_OFFSET #define INTERFACE_IDENTIFIER_PARAMETER_TAG 1 #define MASTER_SLAVE_INDICATOR_PARAMETER_TAG 2 #define M2TP_USER_IDENTIFIER_PARAMETER_TAG 3 #define INFO_PARAMETER_TAG 4 #define DIAGNOSTIC_INFORMATION_PARAMETER_TAG 7 #define HEARTBEAT_DATA_PARAMETER_TAG 9 #define REASON_PARAMETER_TAG 10 #define ERROR_CODE_PARAMETER_TAG 12 #define PROTOCOL_DATA_PARAMETER_TAG 13 static const value_string m2tp_parameter_tag_values[] = { { INTERFACE_IDENTIFIER_PARAMETER_TAG, "Interface Identifier" }, { MASTER_SLAVE_INDICATOR_PARAMETER_TAG, "Master Slave Indicator" }, { M2TP_USER_IDENTIFIER_PARAMETER_TAG, "M2tp User Identifier" }, { INFO_PARAMETER_TAG, "Info" }, { DIAGNOSTIC_INFORMATION_PARAMETER_TAG, "Diagnostic Information" }, { HEARTBEAT_DATA_PARAMETER_TAG, "Heartbeat Data" }, { REASON_PARAMETER_TAG, "Reason" }, { ERROR_CODE_PARAMETER_TAG, "Error Code" }, { PROTOCOL_DATA_PARAMETER_TAG, "Protocol Data" }, { 0, NULL } }; #define PROTOCOL_VERSION_RELEASE_1 1 static const value_string m2tp_protocol_version_values[] = { { PROTOCOL_VERSION_RELEASE_1, "Release 1" }, { 0, NULL } }; #define MESSAGE_CLASS_MGMT_MESSAGE 0 #define MESSAGE_CLASS_SGSM_MESSAGE 3 #define MESSAGE_CLASS_MAUP_MESSAGE 6 #define MESSAGE_CLASS_DATA_MESSAGE 255 static const value_string m2tp_message_class_values[] = { { MESSAGE_CLASS_MGMT_MESSAGE, "Management Messages" }, { MESSAGE_CLASS_SGSM_MESSAGE, "SG State Maintenance Messages" }, { MESSAGE_CLASS_MAUP_MESSAGE, "MTP2 User Adaptation Messages" }, { MESSAGE_CLASS_DATA_MESSAGE, "User Data Messages" }, { 0, NULL } }; /* management messages */ #define MESSAGE_TYPE_ERR 0 /* sg state maintenance messages */ #define MESSAGE_TYPE_UP 1 #define MESSAGE_TYPE_DOWN 2 #define MESSAGE_TYPE_BEAT 3 #define MESSAGE_TYPE_UP_ACK 4 #define MESSAGE_TYPE_DOWN_ACK 5 #define MESSAGE_TYPE_BEAT_ACK 6 /* mtp2 user message */ #define MESSAGE_TYPE_DATA 1 static const value_string m2tp_message_class_type_values[] = { { MESSAGE_CLASS_MGMT_MESSAGE * 256 + MESSAGE_TYPE_ERR, "Error (ERR)" }, { MESSAGE_CLASS_DATA_MESSAGE * 256 + MESSAGE_TYPE_DATA, "Payload data (DATA)" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP, "ASP up (UP)" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN, "ASP down (DOWN)" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT, "Heartbeat (BEAT)" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP_ACK, "ASP up ack (UP ACK)" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN_ACK, "ASP down ack (DOWN ACK)" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT_ACK, "Heartbeat ack (BEAT ACK)" }, { 0, NULL } }; static const value_string m2tp_message_class_type_acro_values[] = { { MESSAGE_CLASS_MGMT_MESSAGE * 256 + MESSAGE_TYPE_ERR, "ERR" }, { MESSAGE_CLASS_DATA_MESSAGE * 256 + MESSAGE_TYPE_DATA, "DATA" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP, "ASP_UP" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN, "ASP_DOWN" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT, "BEAT" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_UP_ACK, "ASP_UP_ACK" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_DOWN_ACK, "ASP_DOWN_ACK" }, { MESSAGE_CLASS_SGSM_MESSAGE * 256 + MESSAGE_TYPE_BEAT_ACK, "BEAT_ACK" }, { 0, NULL } }; #define HEARTBEAT_PERIOD_OFFSET PARAMETER_VALUE_OFFSET #define INTERFACE_IDENTIFIER_LENGTH 4 #define INTERFACE_IDENTIFIER_OFFSET PARAMETER_VALUE_OFFSET #define M2TP_USER_LENGTH 4 #define M2TP_USER_OFFSET PARAMETER_VALUE_OFFSET #define PROTOCOL_DATA_OFFSET PARAMETER_VALUE_OFFSET #define MASTER_SLAVE_LENGTH 4 #define MASTER_SLAVE_OFFSET PARAMETER_VALUE_OFFSET #define REASON_LENGTH 4 #define REASON_OFFSET PARAMETER_VALUE_OFFSET #define HEART_BEAT_DATA_OFFSET PARAMETER_VALUE_OFFSET #define ERROR_CODE_LENGTH 4 #define ERROR_CODE_OFFSET PARAMETER_VALUE_OFFSET #define INFO_STRING_OFFSET PARAMETER_VALUE_OFFSET #define BSN_OFFSET PARAMETER_VALUE_OFFSET #define FSN_OFFSET PARAMETER_VALUE_OFFSET+1 #define M2TP_USER_MTP2 1 #define M2TP_USER_Q921 2 #define M2TP_USER_FRAME_RELAY 3 static const value_string m2tp_user_identifier_values[] = { { M2TP_USER_MTP2, "MTP2" }, { M2TP_USER_Q921, "Q.921" }, { M2TP_USER_FRAME_RELAY, "Frame Relay" }, { 0, NULL }}; #define M2TP_MODE_MASTER 1 #define M2TP_MODE_SLAVE 2 static const value_string m2tp_mode_values[] = { { M2TP_MODE_MASTER, "Master" }, { M2TP_MODE_SLAVE, "Slave" }, { 0, NULL}}; #define M2TP_ERROR_CODE_INVALID_VERSION 1 #define M2TP_ERROR_CODE_INVALID_INTERFACE_IDENTIFIER 2 #define M2TP_ERROR_CODE_INVALID_ADAPTATION_LAYER_IDENTIFIER 3 #define M2TP_ERROR_CODE_INVALID_MESSAGE_TYPE 4 #define M2TP_ERROR_CODE_INVALID_TRAFFIC_HANDLING_MODE 5 #define M2TP_ERROR_CODE_UNEXPECTED_MESSAGE 6 #define M2TP_ERROR_CODE_PROTOCOL_ERROR 7 #define M2TP_ERROR_CODE_INVALID_STREAM_IDENTIFIER 8 #define M2TP_ERROR_CODE_INCOMPATIBLE_MASTER_SLAVE_CONFIGURATION 9 static const value_string m2tp_error_code_values[] = { { M2TP_ERROR_CODE_INVALID_VERSION, "Invalid Version" }, { M2TP_ERROR_CODE_INVALID_INTERFACE_IDENTIFIER, "Invalid Interface Identifier" }, { M2TP_ERROR_CODE_INVALID_ADAPTATION_LAYER_IDENTIFIER, "Invalid Adaptation Layer Identifier" }, { M2TP_ERROR_CODE_INVALID_MESSAGE_TYPE, "Invalid Message Type" }, { M2TP_ERROR_CODE_INVALID_TRAFFIC_HANDLING_MODE, "Invalid Traffic Handling Mode" }, { M2TP_ERROR_CODE_UNEXPECTED_MESSAGE, "Unexpected Message" }, { M2TP_ERROR_CODE_PROTOCOL_ERROR, "Protocol Error" }, { M2TP_ERROR_CODE_INVALID_STREAM_IDENTIFIER, "Invalid Stream Identified" }, { M2TP_ERROR_CODE_INCOMPATIBLE_MASTER_SLAVE_CONFIGURATION,"Incompatible Master Slave Configuration" }, { 0, NULL } }; #define MANAGEMENT_ORDER_REASON_CODE 1 #define MTP_RELEASE_REASON_CODE 2 static const value_string m2tp_reason_code_values[] = { { MANAGEMENT_ORDER_REASON_CODE, "Management Order" }, { MTP_RELEASE_REASON_CODE, "MTP Release" }, { 0, NULL } }; /* Initialize the protocol and registered fields */ static int proto_m2tp = -1; static int hf_m2tp_version = -1; static int hf_m2tp_reserved = -1; static int hf_m2tp_message_class = -1; static int hf_m2tp_message_type = -1; static int hf_m2tp_message_length = -1; static int hf_m2tp_parameter_tag = -1; static int hf_m2tp_parameter_length = -1; static int hf_m2tp_parameter_value = -1; static int hf_m2tp_parameter_padding = -1; static int hf_m2tp_interface_identifier = -1; static int hf_m2tp_user = -1; static int hf_m2tp_master_slave = -1; static int hf_m2tp_info_string = -1; static int hf_m2tp_heartbeat_data = -1; static int hf_m2tp_diagnostic_info = -1; static int hf_m2tp_error_code = -1; static int hf_m2tp_reason = -1; /* Initialize the subtree pointers */ static gint ett_m2tp = -1; static gint ett_m2tp_parameter = -1; static dissector_handle_t mtp2_handle; static int mtp2_proto_id; static guint nr_of_padding_bytes (guint length) { guint remainder; remainder = length % 4; if (remainder == 0) return 0; else return 4 - remainder; } /* Common Header */ static void dissect_m2tp_common_header(tvbuff_t *common_header_tvb, packet_info *pinfo, proto_tree *m2tp_tree) { guint8 version, reserved, message_class, message_type; guint32 message_length; /* Extract the common header */ version = tvb_get_guint8(common_header_tvb, VERSION_OFFSET); reserved = tvb_get_guint8(common_header_tvb, RESERVED_OFFSET); message_class = tvb_get_guint8(common_header_tvb, MESSAGE_CLASS_OFFSET); message_type = tvb_get_guint8(common_header_tvb, MESSAGE_TYPE_OFFSET); message_length = tvb_get_ntohl (common_header_tvb, MESSAGE_LENGTH_OFFSET); if ((check_col(pinfo->cinfo, COL_INFO)) && (message_class != MESSAGE_CLASS_DATA_MESSAGE)){ col_append_str(pinfo->cinfo, COL_INFO, val_to_str(message_class * 256 + message_type, m2tp_message_class_type_acro_values, "reserved")); col_append_str(pinfo->cinfo, COL_INFO, " "); }; if (m2tp_tree) { /* add the components of the common header to the protocol tree */ proto_tree_add_uint(m2tp_tree, hf_m2tp_version, common_header_tvb, VERSION_OFFSET, VERSION_LENGTH, version); proto_tree_add_uint(m2tp_tree, hf_m2tp_reserved, common_header_tvb, RESERVED_OFFSET, RESERVED_LENGTH, reserved); proto_tree_add_uint(m2tp_tree, hf_m2tp_message_class, common_header_tvb, MESSAGE_CLASS_OFFSET, MESSAGE_CLASS_LENGTH, message_class); proto_tree_add_uint_format(m2tp_tree, hf_m2tp_message_type, common_header_tvb, MESSAGE_TYPE_OFFSET, MESSAGE_TYPE_LENGTH, message_type, "Message type: %u (%s)", message_type, val_to_str(message_class * 256 + message_type, m2tp_message_class_type_values, "reserved")); proto_tree_add_uint(m2tp_tree, hf_m2tp_message_length, common_header_tvb, MESSAGE_LENGTH_OFFSET, MESSAGE_LENGTH_LENGTH, message_length); }; } /* Interface Identifier */ static void dissect_m2tp_interface_identifier_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint32 parameter_value; if (parameter_tree) { parameter_value = tvb_get_ntohl(parameter_tvb, PARAMETER_VALUE_OFFSET); proto_tree_add_uint(parameter_tree, hf_m2tp_interface_identifier, parameter_tvb, INTERFACE_IDENTIFIER_OFFSET, INTERFACE_IDENTIFIER_LENGTH, parameter_value); proto_item_set_text(parameter_item, "Interface Identifier (%u)", parameter_value); } } /* Master Slave Indicator */ static void dissect_m2tp_master_slave_parameter (tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint32 parameter_value; if (parameter_tree) { parameter_value = tvb_get_ntohl(parameter_tvb, PARAMETER_VALUE_OFFSET); proto_tree_add_uint(parameter_tree, hf_m2tp_master_slave, parameter_tvb, MASTER_SLAVE_OFFSET, MASTER_SLAVE_LENGTH, parameter_value); proto_item_set_text(parameter_item, "Master Slave Indicator (%s)", val_to_str(parameter_value, m2tp_mode_values, "unknown")); } } /* M2tp User Identifier */ static void dissect_m2tp_user_identifier_parameter (tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint32 parameter_value; if (parameter_tree) { parameter_value = tvb_get_ntohl(parameter_tvb, PARAMETER_VALUE_OFFSET); proto_tree_add_uint(parameter_tree, hf_m2tp_user, parameter_tvb, M2TP_USER_OFFSET, M2TP_USER_LENGTH, parameter_value); proto_item_set_text(parameter_item, "M2TP User Identifier (%u)", parameter_value); } } /* Info String */ static void dissect_m2tp_info_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint16 length, info_string_length; char *info_string; if (parameter_tree) { length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET); info_string_length = length - PARAMETER_HEADER_LENGTH; info_string = (char *)tvb_get_ptr(parameter_tvb, INFO_STRING_OFFSET, info_string_length); proto_tree_add_string(parameter_tree, hf_m2tp_info_string, parameter_tvb, INFO_STRING_OFFSET, info_string_length, info_string); proto_item_set_text(parameter_item, "Info String (%.*s)", info_string_length, info_string); } } /* Diagnostic Information */ static void dissect_m2tp_diagnostic_information_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint16 length, diagnostic_info_length; if (parameter_tree) { length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET); diagnostic_info_length = length - PARAMETER_HEADER_LENGTH; proto_tree_add_bytes(parameter_tree, hf_m2tp_diagnostic_info, parameter_tvb, PARAMETER_VALUE_OFFSET, diagnostic_info_length, tvb_get_ptr(parameter_tvb, PARAMETER_VALUE_OFFSET, diagnostic_info_length)); proto_item_set_text(parameter_item, "Diagnostic information (%u byte%s)", diagnostic_info_length, plurality(diagnostic_info_length, "", "s")); } } /* Heartbeat Data */ static void dissect_m2tp_heartbeat_data_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint16 length, heartbeat_data_length; if (parameter_tree) { length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET); heartbeat_data_length = length - PARAMETER_HEADER_LENGTH; proto_tree_add_bytes(parameter_tree, hf_m2tp_heartbeat_data, parameter_tvb, PARAMETER_VALUE_OFFSET, heartbeat_data_length, tvb_get_ptr(parameter_tvb, PARAMETER_VALUE_OFFSET, heartbeat_data_length)); proto_item_set_text(parameter_item, "Heartbeat data (%u byte%s)", heartbeat_data_length, plurality(heartbeat_data_length, "", "s")); } } /* Reason Parameter */ static void dissect_m2tp_reason_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint32 reason; if (parameter_tree) { reason = tvb_get_ntohl(parameter_tvb, REASON_OFFSET); proto_tree_add_uint(parameter_tree, hf_m2tp_reason, parameter_tvb, REASON_OFFSET, REASON_LENGTH, reason); proto_item_set_text(parameter_item, "Reason parameter (%s)", val_to_str(reason, m2tp_reason_code_values, "unknown")); } } /* Error Code */ static void dissect_m2tp_error_code_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint32 error_code; if (parameter_tree) { error_code = tvb_get_ntohl(parameter_tvb, ERROR_CODE_OFFSET); proto_tree_add_uint(parameter_tree, hf_m2tp_error_code, parameter_tvb, ERROR_CODE_OFFSET, ERROR_CODE_LENGTH, error_code); proto_item_set_text(parameter_item, "Error code parameter (%s)", val_to_str(error_code, m2tp_error_code_values, "unknown")); } } /* Protocol Data */ static void 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) { guint16 length, protocol_data_length, padding_length; tvbuff_t *mtp2_tvb; length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET); padding_length = nr_of_padding_bytes(length); protocol_data_length = length - PARAMETER_HEADER_LENGTH; mtp2_tvb = tvb_new_subset(parameter_tvb, PARAMETER_VALUE_OFFSET, protocol_data_length, protocol_data_length); call_dissector(mtp2_handle, mtp2_tvb, pinfo, tree); if ((check_col(pinfo->cinfo, COL_INFO)) && (!proto_is_protocol_enabled(mtp2_proto_id))) col_append_str(pinfo->cinfo, COL_INFO, "DATA"); if (parameter_tree) { proto_item_set_text(parameter_item, "Protocol data (SS7 message)"); proto_item_set_len(parameter_item, proto_item_get_len(parameter_item) - protocol_data_length - padding_length); proto_item_set_len(m2tp_item, proto_item_get_len(m2tp_item) - protocol_data_length - padding_length); } } /* Unknown Parameter */ static void dissect_m2tp_unknown_parameter(tvbuff_t *parameter_tvb, proto_tree *parameter_tree, proto_item *parameter_item) { guint16 tag, length, parameter_value_length; if (parameter_tree) { tag = tvb_get_ntohs(parameter_tvb, PARAMETER_TAG_OFFSET); length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET); parameter_value_length = length - PARAMETER_HEADER_LENGTH; proto_tree_add_bytes(parameter_tree, hf_m2tp_parameter_value, parameter_tvb, PARAMETER_VALUE_OFFSET, parameter_value_length, tvb_get_ptr(parameter_tvb, PARAMETER_VALUE_OFFSET, parameter_value_length)); proto_item_set_text(parameter_item, "Parameter with tag %u and %u byte%s value", tag, parameter_value_length, plurality(parameter_value_length, "", "s")); } } /* M2TP Parameter */ static void dissect_m2tp_parameter(tvbuff_t *parameter_tvb, packet_info *pinfo, proto_tree *m2tp_tree, proto_item *m2tp_item, proto_tree *tree) { guint16 tag, length, padding_length, total_length; proto_item *parameter_item = NULL; proto_tree *parameter_tree = NULL; /* extract tag and length from the parameter */ tag = tvb_get_ntohs(parameter_tvb, PARAMETER_TAG_OFFSET); length = tvb_get_ntohs(parameter_tvb, PARAMETER_LENGTH_OFFSET); /* calculate padding and total length */ padding_length = nr_of_padding_bytes(length); total_length = length + padding_length; if (tree) { /* create proto_tree stuff */ parameter_item = proto_tree_add_text(m2tp_tree, parameter_tvb, PARAMETER_HEADER_OFFSET, total_length, "Incomplete parameter"); parameter_tree = proto_item_add_subtree(parameter_item, ett_m2tp_parameter); /* add tag and length to the m2tp tree */ proto_tree_add_uint(parameter_tree, hf_m2tp_parameter_tag, parameter_tvb, PARAMETER_TAG_OFFSET, PARAMETER_TAG_LENGTH, tag); proto_tree_add_uint(parameter_tree, hf_m2tp_parameter_length, parameter_tvb, PARAMETER_LENGTH_OFFSET, PARAMETER_LENGTH_LENGTH, length); } switch(tag) { case INTERFACE_IDENTIFIER_PARAMETER_TAG: dissect_m2tp_interface_identifier_parameter(parameter_tvb, parameter_tree, parameter_item); break; case MASTER_SLAVE_INDICATOR_PARAMETER_TAG: dissect_m2tp_master_slave_parameter(parameter_tvb, parameter_tree, parameter_item); break; case M2TP_USER_IDENTIFIER_PARAMETER_TAG: dissect_m2tp_user_identifier_parameter(parameter_tvb, parameter_tree, parameter_item); break; case INFO_PARAMETER_TAG: dissect_m2tp_info_parameter(parameter_tvb, parameter_tree, parameter_item); break; case DIAGNOSTIC_INFORMATION_PARAMETER_TAG: dissect_m2tp_diagnostic_information_parameter(parameter_tvb, parameter_tree, parameter_item); break; case HEARTBEAT_DATA_PARAMETER_TAG: dissect_m2tp_heartbeat_data_parameter(parameter_tvb, parameter_tree, parameter_item); break; case REASON_PARAMETER_TAG: dissect_m2tp_reason_parameter(parameter_tvb, parameter_tree, parameter_item); break; case ERROR_CODE_PARAMETER_TAG: dissect_m2tp_error_code_parameter(parameter_tvb, parameter_tree, parameter_item); break; case PROTOCOL_DATA_PARAMETER_TAG: dissect_m2tp_protocol_data_parameter(parameter_tvb, parameter_tree, parameter_item, pinfo, m2tp_item, tree); break; default: dissect_m2tp_unknown_parameter(parameter_tvb, parameter_tree, parameter_item); break; }; if ((parameter_tree) && (padding_length > 0)) proto_tree_add_bytes(parameter_tree, hf_m2tp_parameter_padding, parameter_tvb, PARAMETER_HEADER_OFFSET + length, padding_length, tvb_get_ptr(parameter_tvb, PARAMETER_HEADER_OFFSET + length, padding_length)); } /* M2TP Message */ static void dissect_m2tp_message(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2tp_item, proto_tree *m2tp_tree, proto_tree *tree) { gint offset, length, padding_length, total_length; tvbuff_t *common_header_tvb, *parameter_tvb; offset = 0; /* extract and process the common header */ common_header_tvb = tvb_new_subset(message_tvb, offset, COMMON_HEADER_LENGTH, COMMON_HEADER_LENGTH); dissect_m2tp_common_header(common_header_tvb, pinfo, m2tp_tree); offset += COMMON_HEADER_LENGTH; /* extract zero or more parameters and process them individually */ while(tvb_reported_length_remaining(message_tvb, offset)) { length = tvb_get_ntohs(message_tvb, offset + PARAMETER_LENGTH_OFFSET); padding_length = nr_of_padding_bytes(length); total_length = length + padding_length; /* create a tvb for the parameter including the padding bytes */ parameter_tvb = tvb_new_subset(message_tvb, offset, total_length, total_length); dissect_m2tp_parameter(parameter_tvb, pinfo, m2tp_tree, m2tp_item, tree); /* get rid of the handled parameter */ offset += total_length; } } /* M2tp */ static void dissect_m2tp(tvbuff_t *message_tvb, packet_info *pinfo, proto_tree *tree) { proto_item *m2tp_item; proto_tree *m2tp_tree; /* make entry in the Protocol column on summary display */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "M2TP"); /* In the interest of speed, if "tree" is NULL, don't do any work not necessary to generate protocol tree items. */ if (tree) { /* create the m2tp protocol tree */ m2tp_item = proto_tree_add_item(tree, proto_m2tp, message_tvb, 0, -1, FALSE); m2tp_tree = proto_item_add_subtree(m2tp_item, ett_m2tp); } else { m2tp_item = NULL; m2tp_tree = NULL; }; /* dissect the message */ dissect_m2tp_message(message_tvb, pinfo, m2tp_item, m2tp_tree, tree); } /* Register the protocol with Ethereal */ void proto_register_m2tp(void) { /* Setup list of header fields */ static hf_register_info hf[] = { { &hf_m2tp_version, { "Version", "m2tp.version", FT_UINT8, BASE_DEC, VALS(m2tp_protocol_version_values), 0x0, "", HFILL} }, { &hf_m2tp_reserved, { "Reserved", "m2tp.reserved", FT_UINT8, BASE_HEX, NULL, 0x0, "", HFILL} }, { &hf_m2tp_message_class, { "Message class", "m2tp.message_class", FT_UINT8, BASE_DEC, VALS(m2tp_message_class_values), 0x0, "", HFILL} }, { &hf_m2tp_message_type, { "Message Type", "m2tp.message_type", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL} }, { &hf_m2tp_message_length, { "Message length", "m2tp.message_length", FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL} }, { &hf_m2tp_parameter_tag, { "Parameter Tag", "m2tp.parameter_tag", FT_UINT16, BASE_DEC, VALS(m2tp_parameter_tag_values), 0x0, "", HFILL} }, { &hf_m2tp_parameter_length, { "Parameter length", "m2tp.parameter_length", FT_UINT16, BASE_DEC, NULL, 0x0, "", HFILL} }, { &hf_m2tp_parameter_value, { "Parameter Value", "m2tp.parameter_value", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL } }, { &hf_m2tp_parameter_padding, { "Padding", "m2tp.parameter_padding", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL } }, { &hf_m2tp_interface_identifier, { "Interface Identifier", "m2tp.interface_identifier", FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL} }, { &hf_m2tp_user, { "M2tp User Identifier", "m2tp.user_identifier", FT_UINT32, BASE_DEC, VALS(m2tp_user_identifier_values), 0x0, "", HFILL} }, { &hf_m2tp_master_slave, { "Master Slave Indicator", "m2tp.master_slave", FT_UINT32, BASE_DEC, VALS(m2tp_mode_values), 0x0, "", HFILL} }, { &hf_m2tp_info_string, { "Info string", "m2tp.info_string", FT_STRING, BASE_DEC, NULL, 0x0, "", HFILL} }, { &hf_m2tp_diagnostic_info, { "Diagnostic information", "m2tp.diagnostic_info", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL } }, { &hf_m2tp_heartbeat_data, { "Heartbeat data", "m2tp.heartbeat_data", FT_BYTES, BASE_NONE, NULL, 0x0, "", HFILL } }, { &hf_m2tp_error_code, { "Error code", "m2tp.error_code", FT_UINT32, BASE_DEC, VALS(m2tp_error_code_values), 0x0, "", HFILL} }, { &hf_m2tp_reason, { "Reason", "m2tp.reason", FT_UINT32, BASE_DEC, NULL, 0x0, "", HFILL} }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_m2tp, &ett_m2tp_parameter, }; /* Register the protocol name and description */ proto_m2tp = proto_register_protocol("MTP 2 Transparent Proxy", "M2TP", "m2tp"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_m2tp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); }; void proto_reg_handoff_m2tp(void) { dissector_handle_t m2tp_handle; mtp2_handle = find_dissector("mtp2"); mtp2_proto_id = proto_get_id_by_filter_name("mtp2"); m2tp_handle = create_dissector_handle(dissect_m2tp, proto_m2tp); dissector_add("sctp.ppi", M2TP_PAYLOAD_PROTO_ID, m2tp_handle); dissector_add("sctp.port", SCTP_PORT_M2TP, m2tp_handle); }