dd859eada4
Change-Id: I36b2731d67f9345d2fd0c23800bba7d2be94c387 Reviewed-on: https://code.wireshark.org/review/6008 Reviewed-by: Bill Meier <wmeier@newsguy.com>
793 lines
27 KiB
C
793 lines
27 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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* 2004 Alejandro Vaquero, add support Conversations for SDP
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* 2006 Alejandro Vaquero, add T30 reassemble and dissection
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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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* - H.245 dissectors should be updated to start conversations for T.38 similar to RTP.
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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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#include "config.h"
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#include <epan/packet.h>
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#include <epan/reassemble.h>
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#include <epan/conversation.h>
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#include <epan/tap.h>
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#include <epan/expert.h>
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#include <epan/strutil.h>
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#include <epan/prefs.h>
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#include <epan/ipproto.h>
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#include <epan/asn1.h>
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#include "packet-t38.h"
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#include "packet-per.h"
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#include "packet-tpkt.h"
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void proto_register_t38(void);
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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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static int t38_tap = -1;
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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", "Never", T38_TPKT_NEVER},
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{"always", "Always", T38_TPKT_ALWAYS},
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{"maybe", "Maybe", T38_TPKT_MAYBE},
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{NULL, NULL, -1}
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};
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/* T38 */
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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 dissector_handle_t t30_hdlc_handle;
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static dissector_handle_t data_handle;
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static gint32 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 guint32 Data_Field_item_num;
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static int proto_t38 = -1;
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#include "packet-t38-hf.c"
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/* T38 setup fields */
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static int hf_t38_setup = -1;
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static int hf_t38_setup_frame = -1;
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static int hf_t38_setup_method = -1;
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/* T38 Data reassemble fields */
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static int hf_t38_fragments = -1;
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static int hf_t38_fragment = -1;
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static int hf_t38_fragment_overlap = -1;
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static int hf_t38_fragment_overlap_conflicts = -1;
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static int hf_t38_fragment_multiple_tails = -1;
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static int hf_t38_fragment_too_long_fragment = -1;
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static int hf_t38_fragment_error = -1;
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static int hf_t38_fragment_count = -1;
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static int hf_t38_reassembled_in = -1;
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static int hf_t38_reassembled_length = -1;
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static gint ett_t38 = -1;
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#include "packet-t38-ett.c"
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static gint ett_t38_setup = -1;
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static gint ett_data_fragment = -1;
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static gint ett_data_fragments = -1;
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static expert_field ei_t38_malformed = EI_INIT;
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static gboolean primary_part = TRUE;
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static guint32 seq_number = 0;
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/* Tables for reassembly of Data fragments. */
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static reassembly_table data_reassembly_table;
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static const fragment_items data_frag_items = {
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/* Fragment subtrees */
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&ett_data_fragment,
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&ett_data_fragments,
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/* Fragment fields */
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&hf_t38_fragments,
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&hf_t38_fragment,
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&hf_t38_fragment_overlap,
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&hf_t38_fragment_overlap_conflicts,
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&hf_t38_fragment_multiple_tails,
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&hf_t38_fragment_too_long_fragment,
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&hf_t38_fragment_error,
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&hf_t38_fragment_count,
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/* Reassembled in field */
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&hf_t38_reassembled_in,
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/* Reassembled length field */
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&hf_t38_reassembled_length,
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/* Reassembled data field */
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NULL,
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/* Tag */
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"Data fragments"
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};
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typedef struct _fragment_key {
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address src;
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address dst;
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guint32 id;
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} fragment_key;
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static conversation_t *p_conv= NULL;
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static t38_conv *p_t38_conv = NULL;
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static t38_conv *p_t38_packet_conv = NULL;
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static t38_conv_info *p_t38_conv_info = NULL;
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static t38_conv_info *p_t38_packet_conv_info = NULL;
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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 void show_setup_info(tvbuff_t *tvb, proto_tree *tree, t38_conv *p_t38_conv);
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/* Preferences bool to control whether or not setup info should be shown */
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static gboolean global_t38_show_setup_info = TRUE;
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/* Can tap up to 4 T38 packets within same packet */
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/* We only tap the primary part, not the redundancy */
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#define MAX_T38_MESSAGES_IN_PACKET 4
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static t38_packet_info t38_info_arr[MAX_T38_MESSAGES_IN_PACKET];
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static int t38_info_current=0;
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static t38_packet_info *t38_info=NULL;
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static void t38_defragment_init(void)
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{
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/* Init reassembly table */
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reassembly_table_init(&data_reassembly_table,
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&addresses_reassembly_table_functions);
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}
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/* Set up an T38 conversation */
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void t38_add_address(packet_info *pinfo,
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address *addr, int port,
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int other_port,
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const gchar *setup_method, guint32 setup_frame_number)
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{
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address null_addr;
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conversation_t* p_conversation;
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t38_conv* p_conversation_data = NULL;
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/*
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* If this isn't the first time this packet has been processed,
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* we've already done this work, so we don't need to do it
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* again.
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*/
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if ((pinfo->fd->flags.visited) || (t38_udp_handle == NULL))
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{
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return;
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}
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SET_ADDRESS(&null_addr, AT_NONE, 0, NULL);
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/*
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* Check if the ip address and port combination is not
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* already registered as a conversation.
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*/
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p_conversation = find_conversation( setup_frame_number, addr, &null_addr, PT_UDP, port, other_port,
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NO_ADDR_B | (!other_port ? NO_PORT_B : 0));
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/*
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* If not, create a new conversation.
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*/
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if ( !p_conversation || p_conversation->setup_frame != setup_frame_number) {
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p_conversation = conversation_new( setup_frame_number, addr, &null_addr, PT_UDP,
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(guint32)port, (guint32)other_port,
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NO_ADDR2 | (!other_port ? NO_PORT2 : 0));
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}
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/* Set dissector */
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conversation_set_dissector(p_conversation, t38_udp_handle);
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/*
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* Check if the conversation has data associated with it.
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*/
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p_conversation_data = (t38_conv*)conversation_get_proto_data(p_conversation, proto_t38);
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/*
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* If not, add a new data item.
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*/
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if ( ! p_conversation_data ) {
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/* Create conversation data */
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p_conversation_data = wmem_new(wmem_file_scope(), t38_conv);
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conversation_add_proto_data(p_conversation, proto_t38, p_conversation_data);
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}
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/*
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* Update the conversation data.
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*/
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g_strlcpy(p_conversation_data->setup_method, setup_method, MAX_T38_SETUP_METHOD_SIZE);
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p_conversation_data->setup_frame_number = setup_frame_number;
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p_conversation_data->src_t38_info.reass_ID = 0;
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p_conversation_data->src_t38_info.reass_start_seqnum = -1;
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p_conversation_data->src_t38_info.reass_data_type = 0;
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p_conversation_data->src_t38_info.last_seqnum = -1;
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p_conversation_data->src_t38_info.packet_lost = 0;
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p_conversation_data->src_t38_info.burst_lost = 0;
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p_conversation_data->src_t38_info.time_first_t4_data = 0;
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p_conversation_data->src_t38_info.additional_hdlc_data_field_counter = 0;
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p_conversation_data->src_t38_info.seqnum_prev_data_field = -1;
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p_conversation_data->dst_t38_info.reass_ID = 0;
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p_conversation_data->dst_t38_info.reass_start_seqnum = -1;
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p_conversation_data->dst_t38_info.reass_data_type = 0;
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p_conversation_data->dst_t38_info.last_seqnum = -1;
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p_conversation_data->dst_t38_info.packet_lost = 0;
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p_conversation_data->dst_t38_info.burst_lost = 0;
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p_conversation_data->dst_t38_info.time_first_t4_data = 0;
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p_conversation_data->dst_t38_info.additional_hdlc_data_field_counter = 0;
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p_conversation_data->dst_t38_info.seqnum_prev_data_field = -1;
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}
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static fragment_head *
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force_reassemble_seq(reassembly_table *table, packet_info *pinfo, guint32 id)
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{
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fragment_head *fd_head;
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fragment_item *fd_i;
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fragment_item *last_fd;
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guint32 dfpos, size, packet_lost, burst_lost, seq_num;
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guint8 *data;
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fd_head = fragment_get(table, pinfo, id, NULL);
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/* have we already seen this frame ?*/
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if (pinfo->fd->flags.visited) {
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if (fd_head != NULL && fd_head->flags & FD_DEFRAGMENTED) {
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return fd_head;
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} else {
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return NULL;
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}
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}
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if (fd_head==NULL){
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/* we must have it to continue */
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return NULL;
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}
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/* check for packet lost and count the burst of packet lost */
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packet_lost = 0;
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burst_lost = 0;
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seq_num = 0;
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for(fd_i=fd_head->next;fd_i;fd_i=fd_i->next) {
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if (seq_num != fd_i->offset) {
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packet_lost += fd_i->offset - seq_num;
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if ( (fd_i->offset - seq_num) > burst_lost ) {
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burst_lost = fd_i->offset - seq_num;
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}
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}
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seq_num = fd_i->offset + 1;
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}
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/* we have received an entire packet, defragment it and
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* free all fragments
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*/
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size=0;
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last_fd=NULL;
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for(fd_i=fd_head->next;fd_i;fd_i=fd_i->next) {
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if(!last_fd || last_fd->offset!=fd_i->offset){
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size+=fd_i->len;
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}
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last_fd=fd_i;
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}
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data = (guint8 *) g_malloc(size);
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fd_head->tvb_data = tvb_new_real_data(data, size, size);
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fd_head->len = size; /* record size for caller */
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/* add all data fragments */
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dfpos = 0;
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last_fd=NULL;
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for (fd_i=fd_head->next;fd_i && fd_i->len + dfpos <= size;fd_i=fd_i->next) {
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if (fd_i->len) {
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if(!last_fd || last_fd->offset!=fd_i->offset){
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memcpy(data+dfpos,tvb_get_ptr(fd_i->tvb_data,0,fd_i->len),fd_i->len);
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dfpos += fd_i->len;
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} else {
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/* duplicate/retransmission/overlap */
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fd_i->flags |= FD_OVERLAP;
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fd_head->flags |= FD_OVERLAP;
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if( (last_fd->len!=fd_i->len)
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|| tvb_memeql(last_fd->tvb_data, 0, tvb_get_ptr(fd_i->tvb_data, 0, last_fd->len), last_fd->len) ){
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fd_i->flags |= FD_OVERLAPCONFLICT;
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fd_head->flags |= FD_OVERLAPCONFLICT;
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}
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}
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}
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last_fd=fd_i;
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}
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/* we have defragmented the pdu, now free all fragments*/
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for (fd_i=fd_head->next;fd_i;fd_i=fd_i->next) {
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if(fd_i->tvb_data){
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tvb_free(fd_i->tvb_data);
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fd_i->tvb_data=NULL;
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}
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}
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/* mark this packet as defragmented */
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fd_head->flags |= FD_DEFRAGMENTED;
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fd_head->reassembled_in=pinfo->fd->num;
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col_append_fstr(pinfo->cinfo, COL_INFO, " (t4-data Reassembled: %d pack lost, %d pack burst lost)", packet_lost, burst_lost);
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p_t38_packet_conv_info->packet_lost = packet_lost;
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p_t38_packet_conv_info->burst_lost = burst_lost;
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return fd_head;
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}
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/* T38 Routines */
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#include "packet-t38-fn.c"
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/* initialize the tap t38_info and the conversation */
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static void
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init_t38_info_conv(packet_info *pinfo)
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{
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/* tap info */
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t38_info_current++;
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if (t38_info_current==MAX_T38_MESSAGES_IN_PACKET) {
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t38_info_current=0;
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}
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t38_info = &t38_info_arr[t38_info_current];
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t38_info->seq_num = 0;
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t38_info->type_msg = 0;
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t38_info->data_value = 0;
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t38_info->t30ind_value =0;
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t38_info->setup_frame_number = 0;
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t38_info->Data_Field_field_type_value = 0;
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t38_info->desc[0] = '\0';
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t38_info->desc_comment[0] = '\0';
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t38_info->time_first_t4_data = 0;
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t38_info->frame_num_first_t4_data = 0;
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/*
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p_t38_packet_conv hold the conversation info in each of the packets.
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p_t38_conv hold the conversation info used to reassemble the HDLC packets, and also the Setup info (e.g SDP)
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If we already have p_t38_packet_conv in the packet, it means we already reassembled the HDLC packets, so we don't
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need to use p_t38_conv
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*/
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p_t38_packet_conv = NULL;
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p_t38_conv = NULL;
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/* Use existing packet info if available */
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p_t38_packet_conv = (t38_conv *)p_get_proto_data(wmem_file_scope(), pinfo, proto_t38, 0);
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/* find the conversation used for Reassemble and Setup Info */
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p_conv = find_conversation(pinfo->fd->num, &pinfo->net_dst, &pinfo->net_src,
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pinfo->ptype,
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pinfo->destport, pinfo->srcport, NO_ADDR_B | NO_PORT_B);
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/* create a conv if it doen't exist */
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if (!p_conv) {
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p_conv = conversation_new(pinfo->fd->num, &pinfo->net_src, &pinfo->net_dst,
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pinfo->ptype, pinfo->srcport, pinfo->destport, NO_ADDR_B | NO_PORT_B);
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/* Set dissector */
|
|
conversation_set_dissector(p_conv, t38_udp_handle);
|
|
}
|
|
|
|
if (!p_t38_packet_conv) {
|
|
p_t38_conv = (t38_conv *)conversation_get_proto_data(p_conv, proto_t38);
|
|
|
|
/* create the conversation if it doen't exist */
|
|
if (!p_t38_conv) {
|
|
p_t38_conv = wmem_new(wmem_file_scope(), t38_conv);
|
|
p_t38_conv->setup_method[0] = '\0';
|
|
p_t38_conv->setup_frame_number = 0;
|
|
|
|
p_t38_conv->src_t38_info.reass_ID = 0;
|
|
p_t38_conv->src_t38_info.reass_start_seqnum = -1;
|
|
p_t38_conv->src_t38_info.reass_data_type = 0;
|
|
p_t38_conv->src_t38_info.last_seqnum = -1;
|
|
p_t38_conv->src_t38_info.packet_lost = 0;
|
|
p_t38_conv->src_t38_info.burst_lost = 0;
|
|
p_t38_conv->src_t38_info.time_first_t4_data = 0;
|
|
p_t38_conv->src_t38_info.additional_hdlc_data_field_counter = 0;
|
|
p_t38_conv->src_t38_info.seqnum_prev_data_field = -1;
|
|
|
|
p_t38_conv->dst_t38_info.reass_ID = 0;
|
|
p_t38_conv->dst_t38_info.reass_start_seqnum = -1;
|
|
p_t38_conv->dst_t38_info.reass_data_type = 0;
|
|
p_t38_conv->dst_t38_info.last_seqnum = -1;
|
|
p_t38_conv->dst_t38_info.packet_lost = 0;
|
|
p_t38_conv->dst_t38_info.burst_lost = 0;
|
|
p_t38_conv->dst_t38_info.time_first_t4_data = 0;
|
|
p_t38_conv->dst_t38_info.additional_hdlc_data_field_counter = 0;
|
|
p_t38_conv->dst_t38_info.seqnum_prev_data_field = -1;
|
|
|
|
conversation_add_proto_data(p_conv, proto_t38, p_t38_conv);
|
|
}
|
|
|
|
/* copy the t38 conversation info to the packet t38 conversation */
|
|
p_t38_packet_conv = wmem_new(wmem_file_scope(), t38_conv);
|
|
g_strlcpy(p_t38_packet_conv->setup_method, p_t38_conv->setup_method, MAX_T38_SETUP_METHOD_SIZE);
|
|
p_t38_packet_conv->setup_frame_number = p_t38_conv->setup_frame_number;
|
|
|
|
memcpy(&(p_t38_packet_conv->src_t38_info), &(p_t38_conv->src_t38_info), sizeof(t38_conv_info));
|
|
memcpy(&(p_t38_packet_conv->dst_t38_info), &(p_t38_conv->dst_t38_info), sizeof(t38_conv_info));
|
|
|
|
p_add_proto_data(wmem_file_scope(), pinfo, proto_t38, 0, p_t38_packet_conv);
|
|
}
|
|
|
|
if (ADDRESSES_EQUAL(&p_conv->key_ptr->addr1, &pinfo->net_src)) {
|
|
p_t38_conv_info = &(p_t38_conv->src_t38_info);
|
|
p_t38_packet_conv_info = &(p_t38_packet_conv->src_t38_info);
|
|
} else {
|
|
p_t38_conv_info = &(p_t38_conv->dst_t38_info);
|
|
p_t38_packet_conv_info = &(p_t38_packet_conv->dst_t38_info);
|
|
}
|
|
|
|
/* update t38_info */
|
|
t38_info->setup_frame_number = p_t38_packet_conv->setup_frame_number;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
}
|
|
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "T.38");
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
|
|
primary_part = TRUE;
|
|
|
|
/* This indicate the item number in the primary part of the T38 message, it is used for the reassemble of T30 packets */
|
|
Data_Field_item_num = 0;
|
|
|
|
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);
|
|
|
|
/* init tap and conv info */
|
|
init_t38_info_conv(pinfo);
|
|
|
|
/* Show Conversation setup info if exists*/
|
|
if (global_t38_show_setup_info) {
|
|
show_setup_info(tvb, tr, p_t38_packet_conv);
|
|
}
|
|
|
|
col_append_str(pinfo->cinfo, COL_INFO, "UDP: UDPTLPacket ");
|
|
|
|
offset = dissect_UDPTLPacket_PDU(tvb, pinfo, tr, NULL);
|
|
|
|
if (tvb_length_remaining(tvb,offset)>0){
|
|
proto_tree_add_expert_format(tr, pinfo, &ei_t38_malformed, tvb, offset, tvb_reported_length_remaining(tvb, offset),
|
|
"[MALFORMED PACKET or wrong preference settings]");
|
|
col_append_str(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;
|
|
tvbuff_t *next_tvb;
|
|
guint16 ifp_packet_number=1;
|
|
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "T.38");
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
|
|
primary_part = TRUE;
|
|
|
|
/* This indicate the item number in the primary part of the T38 message, it is used for the reassemble of T30 packets */
|
|
Data_Field_item_num = 0;
|
|
|
|
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);
|
|
|
|
/* init tap and conv info */
|
|
init_t38_info_conv(pinfo);
|
|
|
|
/* Show Conversation setup info if exists*/
|
|
if (global_t38_show_setup_info) {
|
|
show_setup_info(tvb, tr, p_t38_packet_conv);
|
|
}
|
|
|
|
col_append_str(pinfo->cinfo, COL_INFO, "TCP: IFPPacket");
|
|
|
|
while(tvb_length_remaining(tvb,offset)>0)
|
|
{
|
|
next_tvb = tvb_new_subset_remaining(tvb, offset);
|
|
offset += dissect_IFPPacket_PDU(next_tvb, pinfo, tr, NULL);
|
|
ifp_packet_number++;
|
|
|
|
if(tvb_length_remaining(tvb,offset)>0){
|
|
if(t38_tpkt_usage == T38_TPKT_ALWAYS){
|
|
proto_tree_add_expert_format(tr, pinfo, &ei_t38_malformed, tvb, offset, tvb_reported_length_remaining(tvb, offset),
|
|
"[MALFORMED PACKET or wrong preference settings]");
|
|
col_append_str(pinfo->cinfo, COL_INFO, " [Malformed?]");
|
|
break;
|
|
}else {
|
|
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);
|
|
}
|
|
}
|
|
|
|
/* Look for conversation info and display any setup info found */
|
|
void
|
|
show_setup_info(tvbuff_t *tvb, proto_tree *tree, t38_conv *p_t38_conversation)
|
|
{
|
|
proto_tree *t38_setup_tree;
|
|
proto_item *ti;
|
|
|
|
if (!p_t38_conversation || p_t38_conversation->setup_frame_number == 0) {
|
|
/* there is no Setup info */
|
|
return;
|
|
}
|
|
|
|
ti = proto_tree_add_string_format(tree, hf_t38_setup, tvb, 0, 0,
|
|
"",
|
|
"Stream setup by %s (frame %u)",
|
|
p_t38_conversation->setup_method,
|
|
p_t38_conversation->setup_frame_number);
|
|
PROTO_ITEM_SET_GENERATED(ti);
|
|
t38_setup_tree = proto_item_add_subtree(ti, ett_t38_setup);
|
|
if (t38_setup_tree)
|
|
{
|
|
/* Add details into subtree */
|
|
proto_item* item = proto_tree_add_uint(t38_setup_tree, hf_t38_setup_frame,
|
|
tvb, 0, 0, p_t38_conversation->setup_frame_number);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
item = proto_tree_add_string(t38_setup_tree, hf_t38_setup_method,
|
|
tvb, 0, 0, p_t38_conversation->setup_method);
|
|
PROTO_ITEM_SET_GENERATED(item);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/* Wireshark Protocol Registration */
|
|
void
|
|
proto_register_t38(void)
|
|
{
|
|
static hf_register_info hf[] =
|
|
{
|
|
#include "packet-t38-hfarr.c"
|
|
{ &hf_t38_setup,
|
|
{ "Stream setup", "t38.setup", FT_STRING, BASE_NONE,
|
|
NULL, 0x0, "Stream setup, method and frame number", HFILL }},
|
|
{ &hf_t38_setup_frame,
|
|
{ "Stream frame", "t38.setup-frame", FT_FRAMENUM, BASE_NONE,
|
|
NULL, 0x0, "Frame that set up this stream", HFILL }},
|
|
{ &hf_t38_setup_method,
|
|
{ "Stream Method", "t38.setup-method", FT_STRING, BASE_NONE,
|
|
NULL, 0x0, "Method used to set up this stream", HFILL }},
|
|
{&hf_t38_fragments,
|
|
{"Message fragments", "t38.fragments",
|
|
FT_NONE, BASE_NONE, NULL, 0x00, NULL, HFILL } },
|
|
{&hf_t38_fragment,
|
|
{"Message fragment", "t38.fragment",
|
|
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL } },
|
|
{&hf_t38_fragment_overlap,
|
|
{"Message fragment overlap", "t38.fragment.overlap",
|
|
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } },
|
|
{&hf_t38_fragment_overlap_conflicts,
|
|
{"Message fragment overlapping with conflicting data",
|
|
"t38.fragment.overlap.conflicts",
|
|
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } },
|
|
{&hf_t38_fragment_multiple_tails,
|
|
{"Message has multiple tail fragments",
|
|
"t38.fragment.multiple_tails",
|
|
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } },
|
|
{&hf_t38_fragment_too_long_fragment,
|
|
{"Message fragment too long", "t38.fragment.too_long_fragment",
|
|
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL } },
|
|
{&hf_t38_fragment_error,
|
|
{"Message defragmentation error", "t38.fragment.error",
|
|
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL } },
|
|
{&hf_t38_fragment_count,
|
|
{"Message fragment count", "t38.fragment.count",
|
|
FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL } },
|
|
{&hf_t38_reassembled_in,
|
|
{"Reassembled in", "t38.reassembled.in",
|
|
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL } },
|
|
{&hf_t38_reassembled_length,
|
|
{"Reassembled T38 length", "t38.reassembled.length",
|
|
FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL } },
|
|
};
|
|
|
|
static gint *ett[] =
|
|
{
|
|
&ett_t38,
|
|
#include "packet-t38-ettarr.c"
|
|
&ett_t38_setup,
|
|
&ett_data_fragment,
|
|
&ett_data_fragments
|
|
};
|
|
|
|
static ei_register_info ei[] = {
|
|
{ &ei_t38_malformed, { "t38.malformed", PI_MALFORMED, PI_ERROR, "Malformed packet", EXPFILL }},
|
|
};
|
|
|
|
module_t *t38_module;
|
|
expert_module_t* expert_t38;
|
|
|
|
proto_t38 = proto_register_protocol("T.38", "T.38", "t38");
|
|
proto_register_field_array(proto_t38, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
expert_t38 = expert_register_protocol(proto_t38);
|
|
expert_register_field_array(expert_t38, ei, array_length(ei));
|
|
register_dissector("t38_udp", dissect_t38_udp, proto_t38);
|
|
|
|
/* Init reassemble tables for HDLC */
|
|
register_init_routine(t38_defragment_init);
|
|
|
|
t38_tap = register_tap("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. "
|
|
"To use this option, you must also enable \"Allow subdissectors to reassemble "
|
|
"TCP streams\" in the TCP protocol settings.",
|
|
&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);
|
|
|
|
prefs_register_bool_preference(t38_module, "show_setup_info",
|
|
"Show stream setup information",
|
|
"Where available, show which protocol and frame caused "
|
|
"this T.38 stream to be created",
|
|
&global_t38_show_setup_info);
|
|
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_t38(void)
|
|
{
|
|
static gboolean t38_prefs_initialized = FALSE;
|
|
static guint tcp_port;
|
|
static guint udp_port;
|
|
|
|
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);
|
|
rtp_handle = find_dissector("rtp");
|
|
t30_hdlc_handle = find_dissector("t30.hdlc");
|
|
data_handle = find_dissector("data");
|
|
t38_prefs_initialized = TRUE;
|
|
}
|
|
else {
|
|
dissector_delete_uint("tcp.port", tcp_port, t38_tcp_handle);
|
|
dissector_delete_uint("udp.port", udp_port, t38_udp_handle);
|
|
}
|
|
tcp_port = global_t38_tcp_port;
|
|
udp_port = global_t38_udp_port;
|
|
|
|
dissector_add_uint("tcp.port", tcp_port, t38_tcp_handle);
|
|
dissector_add_uint("udp.port", udp_port, t38_udp_handle);
|
|
|
|
}
|
|
|