forked from osmocom/wireshark
930 lines
29 KiB
C
930 lines
29 KiB
C
/* packet-t38.c
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* Routines for T.38 packet dissection
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* 2003 Hans Viens
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*
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* $Id: packet-t38.c,v 1.6 2004/01/26 22:52:22 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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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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/* Depending on what ASN.1 specification is used you may have to change
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* the preference setting regarding Pre-Corrigendum ASN.1 specification:
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* http://www.itu.int/ITU-T/asn1/database/itu-t/t/t38/1998/T38.html (Pre-Corrigendum=TRUE)
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* http://www.itu.int/ITU-T/asn1/database/itu-t/t/t38/2003/T38(1998).html (Pre-Corrigendum=TRUE)
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*
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* http://www.itu.int/ITU-T/asn1/database/itu-t/t/t38/2003/T38(2002).html (Pre-Corrigendum=FALSE)
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* http://www.itu.int/ITU-T/asn1/database/itu-t/t/t38/2002/t38.html (Pre-Corrigendum=FALSE)
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* http://www.itu.int/ITU-T/asn1/database/itu-t/t/t38/2002-Amd1/T38.html (Pre-Corrigendum=FALSE)
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*/
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/* TO DO:
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* - TCP desegmentation is currently not supported for T.38 IFP directly over TCP.
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* - SDP and H.245 dissectors should be updated to start conversations for T.38 similar to RTP.
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* - It would be nice if we could dissect the T.30 data.
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* - Sometimes the last octet is not high-lighted when selecting something in the tree. Bug in PER dissector?
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* - Add support for RTP payload audio/t38 (draft-jones-avt-audio-t38-03.txt), i.e. T38 in RTP packets.
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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 <glib.h>
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#include <epan/packet.h>
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#include <epan/conversation.h>
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#include <stdio.h>
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#include <string.h>
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#include "prefs.h"
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#include "ipproto.h"
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#include "packet-per.h"
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#include "prefs.h"
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#include "packet-tpkt.h"
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#define PORT_T38 6004
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static guint global_t38_tcp_port = PORT_T38;
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static guint global_t38_udp_port = PORT_T38;
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/*
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* Variables to allow for proper deletion of dissector registration when
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* the user changes port from the gui.
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*/
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static guint tcp_port = 0;
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static guint udp_port = 0;
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/* dissect using the Pre Corrigendum T.38 ASN.1 specification (1998) */
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static gboolean use_pre_corrigendum_asn1_specification = TRUE;
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/* dissect packets that looks like RTP version 2 packets as RTP */
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/* instead of as T.38. This may result in that some T.38 UPTL */
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/* packets with sequence number values higher than 32767 may be */
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/* shown as RTP packets. */
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static gboolean dissect_possible_rtpv2_packets_as_rtp = FALSE;
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/* Reassembly of T.38 PDUs over TPKT over TCP */
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static gboolean t38_tpkt_reassembly = TRUE;
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/* Preference setting whether TPKT header is used when sending T.38 over TCP.
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* The default setting is Maybe where the dissector will look on the first
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* bytes to try to determine whether TPKT header is used or not. This may not
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* work so well in some cases. You may want to change the setting to Always or
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* Newer.
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*/
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#define T38_TPKT_NEVER 0 /* Assume that there is never a TPKT header */
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#define T38_TPKT_ALWAYS 1 /* Assume that there is always a TPKT header */
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#define T38_TPKT_MAYBE 2 /* Assume TPKT if first octets are 03-00-xx-xx */
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static gint t38_tpkt_usage = T38_TPKT_MAYBE;
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static const enum_val_t t38_tpkt_options[] = {
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{"Never", T38_TPKT_NEVER},
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{"Always", T38_TPKT_ALWAYS},
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{"Maybe", T38_TPKT_MAYBE},
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{NULL, -1}
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};
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static dissector_handle_t t38_udp_handle;
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static dissector_handle_t t38_tcp_handle;
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static dissector_handle_t t38_tcp_pdu_handle;
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static dissector_handle_t rtp_handle;
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static guint32 Type_of_msg_value;
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static guint32 Data_Field_field_type_value;
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static guint32 Data_value;
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static guint32 T30ind_value;
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static int proto_t38 = -1;
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static int hf_t38_IFPPacket = -1;
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static int hf_t38_Type_of_msg = -1;
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static int hf_t38_t30_indicator = -1;
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static int hf_t38_data = -1;
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static int hf_t38_Data_Field = -1;
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static int hf_t38_Data_Field_item = -1;
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static int hf_t38_Data_Field_field_type = -1;
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static int hf_t38_Data_Field_field_data = -1;
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static int hf_t38_UDPTLPacket = -1;
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static int hf_t38_seq_number = -1;
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static int hf_t38_primary_ifp_packet = -1;
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static int hf_t38_primary_ifp_packet_length = -1;
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static int hf_t38_error_recovery = -1;
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static int hf_t38_secondary_ifp_packets = -1;
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static int hf_t38_secondary_ifp_packets_item = -1;
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static int hf_t38_secondary_ifp_packets_item_length = -1;
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static int hf_t38_fec_info = -1;
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static int hf_t38_fec_npackets = -1;
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static int hf_t38_fec_data = -1;
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static int hf_t38_fec_data_item = -1;
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static gint ett_t38 = -1;
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static gint ett_t38_IFPPacket = -1;
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static gint ett_t38_Type_of_msg = -1;
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static gint ett_t38_t30_indicator = -1;
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static gint ett_t38_data = -1;
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static gint ett_t38_Data_Field = -1;
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static gint ett_t38_Data_Field_item = -1;
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static gint ett_t38_Data_Field_field_type = -1;
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static gint ett_t38_UDPTLPacket = -1;
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static gint ett_t38_error_recovery = -1;
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static gint ett_t38_secondary_ifp_packets = -1;
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static gint ett_t38_fec_info = -1;
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static gint ett_t38_fec_data = -1;
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static gboolean primary_part = TRUE;
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static guint32 seq_number = 0;
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/* RTP Version is the first 2 bits of the first octet in the UDP payload*/
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#define RTP_VERSION(octet) ((octet) >> 6)
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void proto_reg_handoff_t38(void);
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static int
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dissect_t38_NULL(tvbuff_t *tvb _U_, int offset, packet_info *pinfo _U_, proto_tree *tree _U_)
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{
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return offset;
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}
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static per_choice_t t30_indicator_choice[] = {
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{ 0, "no-signal", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 1, "cng", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 2, "ced", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 3, "v21-preamble", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 4, "v27-2400-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 5, "v27-4800-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 6, "v29-7200-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 7, "v29-9600-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 8, "v17-7200-short-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 9, "v17-7200-long-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 10, "v17-9600-short-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 11, "v17-9600-long-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 12, "v17-12000-short-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 13, "v17-12000-long-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 14, "v17-14400-short-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 15, "v17-14400-long-training", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 16, "v8-ansam", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 17, "v8-signal", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 18, "v34-cntl-channel-1200", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 19, "v34-pri-channel", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 20, "v34-CC-retrain", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 21, "v33-12000-training", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 22, "v33-14400-training", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 0, NULL, 0, NULL }
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};
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static const value_string t30_indicator_vals[] = {
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{ 0, "no-signal" },
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{ 1, "cng" },
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{ 2, "ced" },
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{ 3, "v21-preamble" },
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{ 4, "v27-2400-training" },
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{ 5, "v27-4800-training" },
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{ 6, "v29-7200-training" },
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{ 7, "v29-9600-training" },
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{ 8, "v17-7200-short-training" },
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{ 9, "v17-7200-long-training" },
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{ 10, "v17-9600-short-training" },
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{ 11, "v17-9600-long-training" },
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{ 12, "v17-12000-short-training" },
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{ 13, "v17-12000-long-training" },
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{ 14, "v17-14400-short-training" },
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{ 15, "v17-14400-long-training" },
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{ 16, "v8-ansam" },
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{ 17, "v8-signal" },
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{ 18, "v34-cntl-channel-1200" },
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{ 19, "v34-pri-channel" },
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{ 20, "v34-CC-retrain" },
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{ 21, "v33-12000-training" },
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{ 22, "v33-14400-training" },
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{ 0, NULL },
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};
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static int
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dissect_t38_t30_indicator(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
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{
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offset=dissect_per_choice(tvb, offset, pinfo,
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tree, hf_t38_t30_indicator, ett_t38_t30_indicator,
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t30_indicator_choice, "T30 Indicator", &T30ind_value);
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if (check_col(pinfo->cinfo, COL_INFO) && primary_part){
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col_append_fstr(pinfo->cinfo, COL_INFO, " t30ind: %s",
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val_to_str(T30ind_value,t30_indicator_vals,"<unknown>"));
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}
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return offset;
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}
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static per_choice_t data_choice[] = {
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{ 0, "v21", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 1, "v27-2400", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 2, "v27-4800", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 3, "v29-7200", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 4, "v29-9600", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 5, "v17-7200", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 6, "v17-9600", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 7, "v17-12000", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 8, "v17-14400", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 9, "v8", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 10, "v34-pri-rate", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 11, "v34-CC-1200", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 12, "v34-pri-ch", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 13, "v33-12000", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 14, "v33-14400", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 0, NULL, 0, NULL }
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};
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static const value_string data_vals[] = {
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{ 0, "v21" },
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{ 1, "v27-2400" },
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{ 2, "v27-4800" },
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{ 3, "v29-7200" },
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{ 4, "v29-9600" },
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{ 5, "v17-7200" },
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{ 6, "v17-9600" },
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{ 7, "v17-12000" },
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{ 8, "v17-14400" },
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{ 9, "v8" },
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{ 10, "v34-pri-rate" },
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{ 11, "v34-CC-1200" },
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{ 12, "v34-pri-ch" },
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{ 13, "v33-12000" },
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{ 14, "v33-14400" },
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{ 0, NULL },
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};
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static int
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dissect_t38_data(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
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{
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offset=dissect_per_choice(tvb, offset, pinfo,
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tree, hf_t38_data, ett_t38_data,
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data_choice, "data", &Data_value);
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if (check_col(pinfo->cinfo, COL_INFO) && primary_part){
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col_append_fstr(pinfo->cinfo, COL_INFO, " data:%s:",
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val_to_str(Data_value,data_vals,"<unknown>"));
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}
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return offset;
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}
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static per_choice_t Type_of_msg_choice[] = {
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{ 0, "t30-indicator", ASN1_NO_EXTENSIONS,
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dissect_t38_t30_indicator},
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{ 1, "data", ASN1_NO_EXTENSIONS,
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dissect_t38_data},
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{ 0, NULL, 0, NULL }
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};
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static const value_string Type_of_msg_vals[] = {
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{ 0, "t30-indicator" },
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{ 1, "data" },
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{ 0, NULL}
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};
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static int
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dissect_t38_Type_of_msg(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
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{
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offset=dissect_per_choice(tvb, offset, pinfo,
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tree, hf_t38_Type_of_msg, ett_t38_Type_of_msg,
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Type_of_msg_choice, "Type of message", &Type_of_msg_value);
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return offset;
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}
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static per_choice_t Data_Field_field_type_PreCorrigendum_choice[] = {
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{ 0, "hdlc-data", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 1, "hdlc-sig-end", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 2, "hdlc-fcs-OK", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 3, "hdlc-fcs-BAD", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 4, "hdlc-fcs-OK-sig-end", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 5, "hdlc-fcs-BAD-sig-end", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 6, "t4-non-ecm-data", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 7, "t4-non-ecm-sig-end", ASN1_NO_EXTENSIONS,
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dissect_t38_NULL},
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{ 0, NULL, 0, NULL }
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};
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static per_choice_t Data_Field_field_type_choice[] = {
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{ 0, "hdlc-data", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 1, "hdlc-sig-end", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 2, "hdlc-fcs-OK", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 3, "hdlc-fcs-BAD", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 4, "hdlc-fcs-OK-sig-end", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 5, "hdlc-fcs-BAD-sig-end", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 6, "t4-non-ecm-data", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 7, "t4-non-ecm-sig-end", ASN1_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 8, "cm-message", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 9, "jm-message", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 10, "ci-message", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 11, "v34-rate", ASN1_NOT_EXTENSION_ROOT,
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dissect_t38_NULL},
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{ 0, NULL, 0, NULL }
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};
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static const value_string Data_Field_field_type_vals[] = {
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{ 0, "hdlc-data" },
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{ 1, "hdlc-sig-end" },
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{ 2, "hdlc-fcs-OK" },
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{ 3, "hdlc-fcs-BAD" },
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{ 4, "hdlc-fcs-OK-sig-end" },
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{ 5, "hdlc-fcs-BAD-sig-end" },
|
|
{ 6, "t4-non-ecm-data" },
|
|
{ 7, "t4-non-ecm-sig-end" },
|
|
{ 8, "cm-message" },
|
|
{ 9, "jm-message" },
|
|
{ 10, "ci-message" },
|
|
{ 11, "v34-rate" },
|
|
{ 0, NULL },
|
|
};
|
|
|
|
static int
|
|
dissect_t38_Data_Field_field_type(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
if(use_pre_corrigendum_asn1_specification){
|
|
offset=dissect_per_choice(tvb, offset, pinfo,
|
|
tree, hf_t38_Data_Field_field_type, ett_t38_Data_Field_field_type,
|
|
Data_Field_field_type_PreCorrigendum_choice, "Field Type", &Data_Field_field_type_value);
|
|
}
|
|
else{
|
|
offset=dissect_per_choice(tvb, offset, pinfo,
|
|
tree, hf_t38_Data_Field_field_type, ett_t38_Data_Field_field_type,
|
|
Data_Field_field_type_choice, "Field Type", &Data_Field_field_type_value);
|
|
}
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO) && primary_part){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, " %s",
|
|
val_to_str(Data_Field_field_type_value,Data_Field_field_type_vals,"<unknown>"));
|
|
}
|
|
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_Data_Field_field_data(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
guint32 value_offset = 0;
|
|
guint32 value_len = 0;
|
|
|
|
offset=dissect_per_octet_string(tvb, offset, pinfo,
|
|
tree, hf_t38_Data_Field_field_data, 1, 65535,
|
|
&value_offset, &value_len);
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO) && primary_part){
|
|
if(value_len < 8){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, "[%s]",
|
|
tvb_bytes_to_str(tvb,value_offset,value_len));
|
|
}
|
|
else {
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, "[%s...]",
|
|
tvb_bytes_to_str(tvb,value_offset,7));
|
|
}
|
|
}
|
|
return offset;
|
|
}
|
|
|
|
static per_sequence_t Data_Field_item_sequence[] = {
|
|
{ "field-type", ASN1_NO_EXTENSIONS, ASN1_NOT_OPTIONAL,
|
|
dissect_t38_Data_Field_field_type },
|
|
{ "field-data", ASN1_NO_EXTENSIONS, ASN1_OPTIONAL,
|
|
dissect_t38_Data_Field_field_data },
|
|
{ NULL, 0, 0, NULL }
|
|
};
|
|
|
|
static int
|
|
dissect_t38_Data_Field_item(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_sequence(tvb, offset, pinfo,
|
|
tree, hf_t38_Data_Field_item, ett_t38_Data_Field_item,
|
|
Data_Field_item_sequence);
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_Data_Field(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_sequence_of(tvb, offset, pinfo,
|
|
tree, hf_t38_Data_Field, ett_t38_Data_Field,
|
|
dissect_t38_Data_Field_item);
|
|
return offset;
|
|
}
|
|
|
|
static per_sequence_t IFPPacket_sequence[] = {
|
|
{ "type-of-msg", ASN1_NO_EXTENSIONS, ASN1_NOT_OPTIONAL,
|
|
dissect_t38_Type_of_msg },
|
|
{ "data-field", ASN1_NO_EXTENSIONS, ASN1_OPTIONAL,
|
|
dissect_t38_Data_Field },
|
|
{ NULL, 0, 0, NULL }
|
|
};
|
|
|
|
static int
|
|
dissect_t38_IFPPacket(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_sequence(tvb, offset, pinfo,
|
|
tree, hf_t38_IFPPacket, ett_t38_IFPPacket,
|
|
IFPPacket_sequence);
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_seq_number(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_constrained_integer(tvb, offset, pinfo,
|
|
tree, hf_t38_seq_number, 0, 65535,
|
|
&seq_number, NULL, FALSE);
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, "Seq=%05u ",seq_number);
|
|
}
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_primary_ifp_packet(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
guint32 length;
|
|
primary_part = TRUE;
|
|
|
|
offset=dissect_per_length_determinant(tvb, offset, pinfo,
|
|
tree, hf_t38_primary_ifp_packet_length, &length);
|
|
offset=dissect_t38_IFPPacket(tvb, offset, pinfo, tree);
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_secondary_ifp_packets_item(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
guint32 length;
|
|
|
|
offset=dissect_per_length_determinant(tvb, offset, pinfo,
|
|
tree, hf_t38_secondary_ifp_packets_item_length, &length);
|
|
offset=dissect_t38_IFPPacket(tvb, offset, pinfo, tree);
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_secondary_ifp_packets(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
/* When the field-data is not present, we MUST offset 1 byte*/
|
|
if((Data_Field_field_type_value != 0) &&
|
|
(Data_Field_field_type_value != 6))
|
|
{
|
|
offset=offset+8;
|
|
}
|
|
|
|
offset=dissect_per_sequence_of(tvb, offset, pinfo,
|
|
tree, hf_t38_secondary_ifp_packets, ett_t38_secondary_ifp_packets,
|
|
dissect_t38_secondary_ifp_packets_item);
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_fec_npackets(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_integer(tvb, offset, pinfo,
|
|
tree, hf_t38_fec_npackets,
|
|
NULL, NULL);
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_fec_data_item(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_octet_string(tvb, offset, pinfo,
|
|
tree, hf_t38_fec_data_item, -1, -1,
|
|
NULL, NULL);
|
|
return offset;
|
|
}
|
|
|
|
static int
|
|
dissect_t38_fec_data(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_sequence_of(tvb, offset, pinfo,
|
|
tree, hf_t38_fec_data, ett_t38_fec_data,
|
|
dissect_t38_fec_data_item);
|
|
return offset;
|
|
}
|
|
|
|
static per_sequence_t fec_info_sequence[] = {
|
|
{ "fec-npackets", ASN1_NO_EXTENSIONS, ASN1_NOT_OPTIONAL,
|
|
dissect_t38_fec_npackets },
|
|
{ "fec-data", ASN1_NO_EXTENSIONS, ASN1_NOT_OPTIONAL,
|
|
dissect_t38_fec_data },
|
|
{ NULL, 0, 0, NULL }
|
|
};
|
|
|
|
static int
|
|
dissect_t38_fec_info(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
offset=dissect_per_sequence(tvb, offset, pinfo,
|
|
tree, hf_t38_fec_info, ett_t38_fec_info,
|
|
fec_info_sequence);
|
|
return offset;
|
|
}
|
|
|
|
static per_choice_t error_recovery_choice[] = {
|
|
{ 0, "secondary-ifp-packets", ASN1_NO_EXTENSIONS,
|
|
dissect_t38_secondary_ifp_packets},
|
|
{ 1, "fec-info", ASN1_NO_EXTENSIONS,
|
|
dissect_t38_fec_info},
|
|
{ 0, NULL, 0, NULL }
|
|
};
|
|
|
|
static const value_string error_recovery_vals[] = {
|
|
{ 0, "secondary-ifp-packets" },
|
|
{ 1, "fec-info" },
|
|
{ 0, NULL}
|
|
};
|
|
|
|
static int
|
|
dissect_t38_error_recovery(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
primary_part = FALSE;
|
|
|
|
offset=dissect_per_choice(tvb, offset, pinfo,
|
|
tree, hf_t38_error_recovery, ett_t38_error_recovery,
|
|
error_recovery_choice, "Error recovery", NULL);
|
|
|
|
primary_part = TRUE;
|
|
|
|
return offset;
|
|
}
|
|
|
|
static per_sequence_t UDPTLPacket_sequence[] = {
|
|
{ "seq-number", ASN1_NO_EXTENSIONS, ASN1_NOT_OPTIONAL,
|
|
dissect_t38_seq_number },
|
|
{ "primary-ifp-packet", ASN1_NO_EXTENSIONS, ASN1_NOT_OPTIONAL,
|
|
dissect_t38_primary_ifp_packet },
|
|
{ "error-recovery", ASN1_NO_EXTENSIONS, ASN1_NOT_OPTIONAL,
|
|
dissect_t38_error_recovery },
|
|
{ NULL, 0, 0, NULL }
|
|
};
|
|
|
|
static int
|
|
dissect_t38_UDPTLPacket(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
/* Initialize to something else than data type */
|
|
Data_Field_field_type_value = 1;
|
|
|
|
offset=dissect_per_sequence(tvb, offset, pinfo,
|
|
tree, hf_t38_UDPTLPacket, ett_t38_UDPTLPacket,
|
|
UDPTLPacket_sequence);
|
|
return offset;
|
|
}
|
|
|
|
/* Entry point for dissection */
|
|
static void
|
|
dissect_t38_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
guint8 octet1;
|
|
proto_item *it;
|
|
proto_tree *tr;
|
|
guint32 offset=0;
|
|
|
|
/*
|
|
* XXX - heuristic to check for misidentified packets.
|
|
*/
|
|
if(dissect_possible_rtpv2_packets_as_rtp){
|
|
octet1 = tvb_get_guint8( tvb, offset );
|
|
if(RTP_VERSION(octet1) == 2){
|
|
call_dissector(rtp_handle,tvb,pinfo,tree);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL)){
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "T.38");
|
|
}
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
}
|
|
|
|
primary_part = TRUE;
|
|
|
|
it=proto_tree_add_protocol_format(tree, proto_t38, tvb, 0, -1,
|
|
"ITU-T Recommendation T.38");
|
|
tr=proto_item_add_subtree(it, ett_t38);
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, "UDP: UDPTLPacket ");
|
|
}
|
|
|
|
offset=dissect_t38_UDPTLPacket(tvb, offset, pinfo, tr);
|
|
|
|
if(offset&0x07){
|
|
offset=(offset&0xfffffff8)+8;
|
|
}
|
|
if(tvb_length_remaining(tvb,offset>>3)>0){
|
|
if(tr){
|
|
proto_tree_add_text(tr, tvb, offset, tvb_reported_length_remaining(tvb, offset),
|
|
"[MALFORMED PACKET or wrong preference settings]");
|
|
}
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, " [Malformed?]");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
dissect_t38_tcp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
proto_item *it;
|
|
proto_tree *tr;
|
|
guint32 offset=0;
|
|
guint16 ifp_packet_number=1;
|
|
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL)){
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "T.38");
|
|
}
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
}
|
|
|
|
it=proto_tree_add_protocol_format(tree, proto_t38, tvb, 0, -1,
|
|
"ITU-T Recommendation T.38");
|
|
tr=proto_item_add_subtree(it, ett_t38);
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, "TCP: IFPPacket");
|
|
}
|
|
|
|
while(tvb_length_remaining(tvb,offset>>3)>0)
|
|
{
|
|
offset=dissect_t38_IFPPacket(tvb, offset, pinfo, tr);
|
|
ifp_packet_number++;
|
|
|
|
if(offset&0x07){
|
|
offset=(offset&0xfffffff8)+8;
|
|
}
|
|
|
|
if(tvb_length_remaining(tvb,offset>>3)>0){
|
|
if(t38_tpkt_usage == T38_TPKT_ALWAYS){
|
|
if(tr){
|
|
proto_tree_add_text(tr, tvb, offset, tvb_reported_length_remaining(tvb, offset),
|
|
"[MALFORMED PACKET or wrong preference settings]");
|
|
}
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, " [Malformed?]");
|
|
}
|
|
break;
|
|
}
|
|
else {
|
|
if (check_col(pinfo->cinfo, COL_INFO)){
|
|
col_append_fstr(pinfo->cinfo, COL_INFO, " IFPPacket#%u",ifp_packet_number);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
static void
|
|
dissect_t38_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
primary_part = TRUE;
|
|
|
|
if(t38_tpkt_usage == T38_TPKT_ALWAYS){
|
|
dissect_tpkt_encap(tvb,pinfo,tree,t38_tpkt_reassembly,t38_tcp_pdu_handle);
|
|
}
|
|
else if((t38_tpkt_usage == T38_TPKT_NEVER) || (is_tpkt(tvb,1) == -1)){
|
|
dissect_t38_tcp_pdu(tvb, pinfo, tree);
|
|
}
|
|
else {
|
|
dissect_tpkt_encap(tvb,pinfo,tree,t38_tpkt_reassembly,t38_tcp_pdu_handle);
|
|
}
|
|
}
|
|
|
|
static void
|
|
dissect_t38(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
if(pinfo->ipproto == IP_PROTO_TCP)
|
|
{
|
|
dissect_t38_tcp(tvb, pinfo, tree);
|
|
}
|
|
else if(pinfo->ipproto == IP_PROTO_UDP)
|
|
{
|
|
dissect_t38_udp(tvb, pinfo, tree);
|
|
}
|
|
}
|
|
|
|
/* Ethereal Protocol Registration */
|
|
void
|
|
proto_register_t38(void)
|
|
{
|
|
static hf_register_info hf[] =
|
|
{
|
|
{ &hf_t38_IFPPacket,
|
|
{ "IFPPacket", "t38.IFPPacket", FT_NONE, BASE_NONE,
|
|
NULL, 0, "IFPPacket sequence", HFILL }},
|
|
{ &hf_t38_Type_of_msg,
|
|
{ "Type of msg", "t38.Type_of_msg_type", FT_UINT32, BASE_DEC,
|
|
VALS(Type_of_msg_vals), 0, "Type_of_msg choice", HFILL }},
|
|
{ &hf_t38_t30_indicator,
|
|
{ "T30 indicator", "t38.t30_indicator", FT_UINT32, BASE_DEC,
|
|
VALS(t30_indicator_vals), 0, "t30_indicator", HFILL }},
|
|
{ &hf_t38_data,
|
|
{ "data", "t38.t38_data", FT_UINT32, BASE_DEC,
|
|
VALS(data_vals), 0, "data", HFILL }},
|
|
{ &hf_t38_Data_Field,
|
|
{ "Data Field", "t38.Data_Field", FT_NONE, BASE_NONE,
|
|
NULL, 0, "Data_Field sequence of", HFILL }},
|
|
{ &hf_t38_Data_Field_item,
|
|
{ "Data_Field_item", "t38.Data_Field_item", FT_NONE, BASE_NONE,
|
|
NULL, 0, "Data_Field_item sequence", HFILL }},
|
|
{ &hf_t38_Data_Field_field_type,
|
|
{ "Data_Field_field_type", "t38.Data_Field_field_type", FT_UINT32, BASE_DEC,
|
|
VALS(Data_Field_field_type_vals), 0, "Data_Field_field_type choice", HFILL }},
|
|
{ &hf_t38_Data_Field_field_data,
|
|
{ "Data_Field_field_data", "t38.Data_Field_field_data", FT_BYTES, BASE_HEX,
|
|
NULL, 0, "Data_Field_field_data octet string", HFILL }},
|
|
{ &hf_t38_UDPTLPacket,
|
|
{ "UDPTLPacket", "t38.UDPTLPacket", FT_NONE, BASE_NONE,
|
|
NULL, 0, "UDPTLPacket sequence", HFILL }},
|
|
{ &hf_t38_seq_number,
|
|
{ "Sequence number", "t38.seq_number", FT_UINT32, BASE_DEC,
|
|
NULL, 0, "seq_number", HFILL }},
|
|
{ &hf_t38_primary_ifp_packet,
|
|
{ "Primary IFPPacket", "t38.primary_ifp_packet", FT_BYTES, BASE_HEX,
|
|
NULL, 0, "primary_ifp_packet octet string", HFILL }},
|
|
{ &hf_t38_primary_ifp_packet_length,
|
|
{ "primary_ifp_packet_length", "t38.primary_ifp_packet_length", FT_UINT32, BASE_DEC,
|
|
NULL, 0, "primary_ifp_packet_length", HFILL }},
|
|
{ &hf_t38_error_recovery,
|
|
{ "Error recovery", "t38.error_recovery", FT_UINT32, BASE_DEC,
|
|
VALS(error_recovery_vals), 0, "error_recovery choice", HFILL }},
|
|
{ &hf_t38_secondary_ifp_packets,
|
|
{ "Secondary IFPPackets", "t38.secondary_ifp_packets", FT_NONE, BASE_NONE,
|
|
NULL, 0, "secondary_ifp_packets sequence of", HFILL }},
|
|
{ &hf_t38_secondary_ifp_packets_item,
|
|
{ "Secondary IFPPackets item", "t38.secondary_ifp_packets_item", FT_BYTES, BASE_HEX,
|
|
NULL, 0, "secondary_ifp_packets_item octet string", HFILL }},
|
|
{ &hf_t38_secondary_ifp_packets_item_length,
|
|
{ "secondary_ifp_packets_item_length", "t38.secondary_ifp_packets_item_length", FT_UINT32, BASE_DEC,
|
|
NULL, 0, "secondary_ifp_packets_item_length", HFILL }},
|
|
{ &hf_t38_fec_info,
|
|
{ "Fec info", "t38.fec_info", FT_NONE, BASE_NONE,
|
|
NULL, 0, "fec_info sequence", HFILL }},
|
|
{ &hf_t38_fec_npackets,
|
|
{ "Fec npackets", "h245.fec_npackets", FT_INT32, BASE_DEC,
|
|
NULL, 0, "fec_npackets value", HFILL }},
|
|
{ &hf_t38_fec_data,
|
|
{ "Fec data", "t38.fec_data", FT_NONE, BASE_NONE,
|
|
NULL, 0, "fec_data sequence of", HFILL }},
|
|
{ &hf_t38_fec_data_item,
|
|
{ "t38_fec_data_item", "t38.t38_fec_data_item", FT_BYTES, BASE_HEX,
|
|
NULL, 0, "t38_fec_data_item octet string", HFILL }},
|
|
};
|
|
|
|
static gint *ett[] =
|
|
{
|
|
&ett_t38,
|
|
&ett_t38_IFPPacket,
|
|
&ett_t38_Type_of_msg,
|
|
&ett_t38_t30_indicator,
|
|
&ett_t38_data,
|
|
&ett_t38_Data_Field,
|
|
&ett_t38_Data_Field_item,
|
|
&ett_t38_Data_Field_field_type,
|
|
&ett_t38_UDPTLPacket,
|
|
&ett_t38_error_recovery,
|
|
&ett_t38_secondary_ifp_packets,
|
|
&ett_t38_fec_info,
|
|
&ett_t38_fec_data,
|
|
};
|
|
module_t *t38_module;
|
|
|
|
proto_t38 = proto_register_protocol("T38", "T38", "t38");
|
|
proto_register_field_array(proto_t38, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
register_dissector("t38", dissect_t38, proto_t38);
|
|
|
|
t38_module = prefs_register_protocol(proto_t38, proto_reg_handoff_t38);
|
|
prefs_register_bool_preference(t38_module, "use_pre_corrigendum_asn1_specification",
|
|
"Use the Pre-Corrigendum ASN.1 specification",
|
|
"Whether the T.38 dissector should decode using the Pre-Corrigendum T.38 "
|
|
"ASN.1 specification (1998).",
|
|
&use_pre_corrigendum_asn1_specification);
|
|
prefs_register_bool_preference(t38_module, "dissect_possible_rtpv2_packets_as_rtp",
|
|
"Dissect possible RTP version 2 packets with RTP dissector",
|
|
"Whether a UDP packet that looks like RTP version 2 packet will "
|
|
"be dissected as RTP packet or T.38 packet. If enabled there is a risk that T.38 UDPTL "
|
|
"packets with sequence number higher than 32767 may be dissected as RTP.",
|
|
&dissect_possible_rtpv2_packets_as_rtp);
|
|
prefs_register_uint_preference(t38_module, "tcp.port",
|
|
"T.38 TCP Port",
|
|
"Set the TCP port for T.38 messages",
|
|
10, &global_t38_tcp_port);
|
|
prefs_register_uint_preference(t38_module, "udp.port",
|
|
"T.38 UDP Port",
|
|
"Set the UDP port for T.38 messages",
|
|
10, &global_t38_udp_port);
|
|
prefs_register_bool_preference(t38_module, "reassembly",
|
|
"Reassemble T.38 PDUs over TPKT over TCP",
|
|
"Whether the dissector should reassemble T.38 PDUs spanning multiple TCP segments "
|
|
"when TPKT is used over TCP",
|
|
&t38_tpkt_reassembly);
|
|
prefs_register_enum_preference(t38_module, "tpkt_usage",
|
|
"TPKT used over TCP",
|
|
"Whether T.38 is used with TPKT for TCP",
|
|
(gint *)&t38_tpkt_usage,t38_tpkt_options,FALSE);
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_t38(void)
|
|
{
|
|
static int t38_prefs_initialized = FALSE;
|
|
|
|
if (!t38_prefs_initialized) {
|
|
t38_udp_handle=create_dissector_handle(dissect_t38_udp, proto_t38);
|
|
t38_tcp_handle=create_dissector_handle(dissect_t38_tcp, proto_t38);
|
|
t38_tcp_pdu_handle=create_dissector_handle(dissect_t38_tcp_pdu, proto_t38);
|
|
t38_prefs_initialized = TRUE;
|
|
}
|
|
else {
|
|
dissector_delete("tcp.port", tcp_port, t38_tcp_handle);
|
|
dissector_delete("udp.port", udp_port, t38_udp_handle);
|
|
}
|
|
tcp_port = global_t38_tcp_port;
|
|
udp_port = global_t38_udp_port;
|
|
|
|
dissector_add("tcp.port", tcp_port, t38_tcp_handle);
|
|
dissector_add("udp.port", udp_port, t38_udp_handle);
|
|
|
|
rtp_handle = find_dissector("rtp");
|
|
}
|