1552 lines
50 KiB
C
1552 lines
50 KiB
C
/* packet-mgcp.c
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* Routines for mgcp packet disassembly
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* RFC 2705
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*
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* $Id: packet-mgcp.c,v 1.43 2003/12/05 09:25:41 guy Exp $
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*
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* Copyright (c) 2000 by Ed Warnicke <hagbard@physics.rutgers.edu>
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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 1999 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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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "plugins/plugin_api.h"
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#include "moduleinfo.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <gmodule.h>
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#include <ctype.h>
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#include <time.h>
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#include <string.h>
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#include <epan/packet.h>
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#include <epan/resolv.h>
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#include "prefs.h"
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#include <epan/strutil.h>
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#include <epan/conversation.h>
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#include "packet-mgcp.h"
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#include "plugins/plugin_api_defs.h"
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#ifndef ENABLE_STATIC
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G_MODULE_EXPORT const gchar version[] = VERSION;
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#endif
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#define TCP_PORT_MGCP_GATEWAY 2427
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#define UDP_PORT_MGCP_GATEWAY 2427
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#define TCP_PORT_MGCP_CALLAGENT 2727
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#define UDP_PORT_MGCP_CALLAGENT 2727
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void proto_reg_handoff_mgcp(void);
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/* Define the mgcp proto */
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static int proto_mgcp = -1;
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/* Define many many headers for mgcp */
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static int hf_mgcp_req = -1;
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static int hf_mgcp_req_verb = -1;
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static int hf_mgcp_req_endpoint = -1;
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static int hf_mgcp_req_frame = -1;
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static int hf_mgcp_rsp = -1;
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static int hf_mgcp_rsp_frame = -1;
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static int hf_mgcp_time = -1;
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static int hf_mgcp_transid = -1;
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static int hf_mgcp_version = -1;
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static int hf_mgcp_rsp_rspcode = -1;
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static int hf_mgcp_rsp_rspstring = -1;
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static int hf_mgcp_param_rspack = -1;
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static int hf_mgcp_param_bearerinfo = -1;
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static int hf_mgcp_param_callid = -1;
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static int hf_mgcp_param_connectionid = -1;
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static int hf_mgcp_param_secondconnectionid = -1;
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static int hf_mgcp_param_notifiedentity = -1;
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static int hf_mgcp_param_requestid = -1;
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static int hf_mgcp_param_localconnoptions = -1;
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static int hf_mgcp_param_connectionmode = -1;
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static int hf_mgcp_param_reqevents = -1;
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static int hf_mgcp_param_restartmethod = -1;
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static int hf_mgcp_param_restartdelay = -1;
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static int hf_mgcp_param_signalreq = -1;
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static int hf_mgcp_param_digitmap = -1;
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static int hf_mgcp_param_observedevent = -1;
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static int hf_mgcp_param_connectionparam = -1;
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static int hf_mgcp_param_reasoncode = -1;
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static int hf_mgcp_param_eventstates = -1;
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static int hf_mgcp_param_specificendpoint = -1;
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static int hf_mgcp_param_secondendpointid = -1;
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static int hf_mgcp_param_reqinfo = -1;
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static int hf_mgcp_param_quarantinehandling = -1;
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static int hf_mgcp_param_detectedevents = -1;
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static int hf_mgcp_param_capabilities = -1;
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static int hf_mgcp_param_extention = -1;
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static int hf_mgcp_param_invalid = -1;
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static int hf_mgcp_messagecount = -1;
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static int hf_mgcp_dup = -1;
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static int hf_mgcp_req_dup = -1;
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static int hf_mgcp_rsp_dup = -1;
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/*
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* Define the trees for mgcp
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* We need one for MGCP itself and one for the MGCP paramters
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*/
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static int ett_mgcp = -1;
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static int ett_mgcp_param = -1;
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/*
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* Define the tap for mgcp
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*/
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static int mgcp_tap = -1;
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/*
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* Here are the global variables associated with
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* the various user definable characteristics of the dissection
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*
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* MGCP has two kinds of "agents", gateways and callagents. Callagents
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* control gateways in a master/slave sort of arrangement. Since gateways
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* and callagents have different well known ports and could both
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* operate under either udp or tcp we have rather a lot of port info to
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* specify.
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*
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* global_mgcp_raw_text determines whether we are going to display
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* the raw text of the mgcp message, much like the HTTP dissector does.
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*
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* global_mgcp_dissect_tree determines whether we are going to display
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* a detailed tree that expresses a somewhat more semantically meaningful
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* decode.
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*/
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static int global_mgcp_gateway_tcp_port = TCP_PORT_MGCP_GATEWAY;
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static int global_mgcp_gateway_udp_port = UDP_PORT_MGCP_GATEWAY;
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static int global_mgcp_callagent_tcp_port = TCP_PORT_MGCP_CALLAGENT;
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static int global_mgcp_callagent_udp_port = UDP_PORT_MGCP_CALLAGENT;
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static gboolean global_mgcp_raw_text = FALSE;
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static gboolean global_mgcp_dissect_tree = TRUE;
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static gboolean global_mgcp_message_count = FALSE;
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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 int gateway_tcp_port = 0;
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static int gateway_udp_port = 0;
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static int callagent_tcp_port = 0;
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static int callagent_udp_port = 0;
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/* Some basic utility functions that are specific to this dissector */
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static gboolean is_mgcp_verb(tvbuff_t *tvb, gint offset, gint maxlength);
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static gboolean is_mgcp_rspcode(tvbuff_t *tvb, gint offset, gint maxlength);
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static gint tvb_parse_param(tvbuff_t *tvb, gint offset, gint maxlength,
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int** hf);
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/*
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* The various functions that either dissect some
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* subpart of MGCP. These aren't really proto dissectors but they
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* are written in the same style.
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*/
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static void dissect_mgcp_message(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *tree,proto_tree *mgcp_tree, proto_tree *ti);
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static void dissect_mgcp_firstline(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *tree, mgcp_info_t *mi);
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static void dissect_mgcp_params(tvbuff_t *tvb,
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proto_tree *tree);
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static void mgcp_raw_text_add(tvbuff_t *tvb,
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proto_tree *tree);
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/*
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* Some functions which should be moved to a library
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* as I think that people may find them of general usefulness.
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*/
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static gint tvb_skip_wsp(tvbuff_t* tvb, gint offset, gint maxlength);
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static gint tvb_find_null_line(tvbuff_t* tvb, gint offset, gint len,
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gint* next_offset);
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static gint tvb_find_dot_line(tvbuff_t* tvb, gint offset,
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gint len, gint* next_offset);
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static gboolean is_rfc2234_alpha(guint8 c);
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static dissector_handle_t sdp_handle;
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/*
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* Init Hash table stuff
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*/
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typedef struct _mgcp_call_info_key {
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guint32 transid;
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conversation_t *conversation;
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} mgcp_call_info_key;
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static GMemChunk *mgcp_call_info_key_chunk;
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static GMemChunk *mgcp_call_info_value_chunk;
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static GHashTable *mgcp_calls;
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/* compare 2 keys */
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static gint
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mgcp_call_equal(gconstpointer k1, gconstpointer k2)
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{
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const mgcp_call_info_key* key1 = (const mgcp_call_info_key*) k1;
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const mgcp_call_info_key* key2 = (const mgcp_call_info_key*) k2;
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return (key1->transid == key2->transid &&
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key1->conversation == key2->conversation);
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}
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/* calculate a hash key */
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static guint
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mgcp_call_hash(gconstpointer k)
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{
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const mgcp_call_info_key* key = (const mgcp_call_info_key*) k;
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return key->transid + (guint32)(key->conversation);
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}
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/*
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* dissect_mgcp - The dissector for the Media Gateway Control Protocol
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*/
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static void
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dissect_mgcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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gint sectionlen;
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guint32 num_messages;
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gint tvb_sectionend,tvb_sectionbegin, tvb_len, tvb_current_len;
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proto_tree *mgcp_tree, *ti;
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/* Initialize variables */
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tvb_sectionend = 0;
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tvb_sectionbegin = tvb_sectionend;
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sectionlen = 0;
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tvb_len = tvb_length(tvb);
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tvb_current_len = tvb_len;
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num_messages = 0;
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mgcp_tree = NULL;
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ti = NULL;
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/*
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* Set the columns now, so that they'll be set correctly if we throw
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* an exception. We can set them later as well....
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*/
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_add_str(pinfo->cinfo, COL_PROTOCOL, "MGCP");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_clear(pinfo->cinfo, COL_INFO);
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/*
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* Check to see whether we're really dealing with MGCP by looking
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* for a valid MGCP verb or response code. This isn't infallible,
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* but its cheap and its better than nothing.
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*/
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if(is_mgcp_verb(tvb,0,tvb_len) || is_mgcp_rspcode(tvb,0,tvb_len)){
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/*
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* Loop through however many mgcp messages may be stuck in
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* this packet using piggybacking
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*/
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do{
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num_messages++;
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if(tree){
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/* Create out mgcp subtree */
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ti = proto_tree_add_item(tree,proto_mgcp,tvb,0,0, FALSE);
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mgcp_tree = proto_item_add_subtree(ti, ett_mgcp);
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}
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sectionlen = tvb_find_dot_line(tvb, tvb_sectionbegin, -1,
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&tvb_sectionend);
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if( sectionlen != -1){
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dissect_mgcp_message(tvb_new_subset(tvb, tvb_sectionbegin,
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sectionlen, -1),
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pinfo, tree, mgcp_tree,ti);
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tvb_sectionbegin = tvb_sectionend;
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}
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else {
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break;
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}
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} while(tvb_sectionend < tvb_len );
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if(mgcp_tree){
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proto_tree_add_uint_hidden(mgcp_tree, hf_mgcp_messagecount, tvb,
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0 ,0 , num_messages);
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}
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/*
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* Add our column information we do this after dissecting SDP
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* in order to prevent the column info changing to reflect the SDP.
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* XXX - can we do this with a fence?
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*/
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tvb_sectionbegin = 0;
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if (check_col(pinfo->cinfo, COL_PROTOCOL)){
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if( global_mgcp_message_count == TRUE ){
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if(num_messages > 1){
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col_add_fstr(pinfo->cinfo, COL_PROTOCOL, "MGCP (%i messages)",num_messages);
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}
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else {
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col_add_fstr(pinfo->cinfo, COL_PROTOCOL, "MGCP (%i message)",num_messages);
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}
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}
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else {
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col_add_str(pinfo->cinfo, COL_PROTOCOL, "MGCP");
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}
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}
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if (check_col(pinfo->cinfo, COL_INFO) ){
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sectionlen = tvb_find_line_end(tvb, tvb_sectionbegin,-1,
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&tvb_sectionend,FALSE);
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col_prepend_fstr(pinfo->cinfo, COL_INFO, "%s",
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tvb_format_text(tvb,tvb_sectionbegin,sectionlen));
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}
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}
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}
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static void
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dissect_mgcp_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
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proto_tree *mgcp_tree, proto_tree *ti){
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/* Declare variables */
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gint sectionlen;
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gint tvb_sectionend,tvb_sectionbegin, tvb_len, tvb_current_len;
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tvbuff_t *next_tvb;
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static mgcp_info_t mi;
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/* Initialize variables */
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tvb_sectionend = 0;
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tvb_sectionbegin = tvb_sectionend;
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sectionlen = 0;
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tvb_len = tvb_length(tvb);
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tvb_current_len = tvb_len;
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/*
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* Check to see whether we're really dealing with MGCP by looking
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* for a valid MGCP verb or response code. This isn't infallible,
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* but its cheap and its better than nothing.
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*/
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if(is_mgcp_verb(tvb,0,tvb_len) || is_mgcp_rspcode(tvb,0,tvb_len)){
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/* dissect first line */
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tvb_sectionbegin = 0;
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tvb_current_len = tvb_len;
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tvb_sectionend = tvb_sectionbegin;
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sectionlen = tvb_find_line_end(tvb,0,-1,&tvb_sectionend,FALSE);
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if( sectionlen > 0){
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dissect_mgcp_firstline(tvb_new_subset(tvb, tvb_sectionbegin,
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sectionlen,-1), pinfo,
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mgcp_tree, &mi);
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}
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tvb_sectionbegin = tvb_sectionend;
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/* dissect params */
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if(tvb_sectionbegin < tvb_len){
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sectionlen = tvb_find_null_line(tvb, tvb_sectionbegin, -1,
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&tvb_sectionend);
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dissect_mgcp_params(tvb_new_subset(tvb, tvb_sectionbegin,
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sectionlen, -1),
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mgcp_tree);
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tvb_sectionbegin = tvb_sectionend;
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}
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/* set the mgcp payload length correctly so we don't include the
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* encapsulated SDP
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*/
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sectionlen = tvb_sectionend;
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proto_item_set_len(ti,sectionlen);
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/* Display the raw text of the mgcp message if desired */
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/* Do we want to display the raw text of our MGCP packet? */
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if(global_mgcp_raw_text) {
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if (tree)
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mgcp_raw_text_add(tvb, mgcp_tree);
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}
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/* dissect sdp payload */
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if( tvb_sectionend < tvb_len){
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next_tvb = tvb_new_subset(tvb, tvb_sectionend, -1, -1);
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call_dissector(sdp_handle, next_tvb, pinfo, tree);
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}
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}
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}
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/*
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* Add the raw text of the message to the dissect tree if appropriate
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* preferences are specified.
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*/
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static void mgcp_raw_text_add(tvbuff_t *tvb, proto_tree *tree){
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gint tvb_linebegin,tvb_lineend,tvb_len,linelen;
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tvb_linebegin = 0;
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tvb_len = tvb_length(tvb);
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do {
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tvb_find_line_end(tvb,tvb_linebegin,-1,&tvb_lineend,FALSE);
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linelen = tvb_lineend - tvb_linebegin;
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proto_tree_add_text(tree, tvb, tvb_linebegin, linelen,
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"%s", tvb_format_text(tvb,tvb_linebegin,
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linelen));
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tvb_linebegin = tvb_lineend;
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} while ( tvb_lineend < tvb_len );
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}
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/* Discard and init any state we've saved */
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static void
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mgcp_init_protocol(void)
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{
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if (mgcp_calls != NULL) {
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g_hash_table_destroy(mgcp_calls);
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mgcp_calls = NULL;
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}
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if (mgcp_call_info_key_chunk != NULL) {
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g_mem_chunk_destroy(mgcp_call_info_key_chunk);
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mgcp_call_info_key_chunk = NULL;
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}
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if (mgcp_call_info_value_chunk != NULL) {
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g_mem_chunk_destroy(mgcp_call_info_value_chunk);
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mgcp_call_info_value_chunk = NULL;
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}
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mgcp_calls = g_hash_table_new(mgcp_call_hash, mgcp_call_equal);
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mgcp_call_info_key_chunk = g_mem_chunk_new("call_info_key_chunk",
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sizeof(mgcp_call_info_key),
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200 * sizeof(mgcp_call_info_key),
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G_ALLOC_ONLY);
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mgcp_call_info_value_chunk = g_mem_chunk_new("call_info_value_chunk",
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sizeof(mgcp_call_t),
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200 * sizeof(mgcp_call_t),
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G_ALLOC_ONLY);
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}
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/* Register all the bits needed with the filtering engine */
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|
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void
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proto_register_mgcp(void)
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{
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static hf_register_info hf[] = {
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{ &hf_mgcp_req,
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{ "Request", "mgcp.req", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
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"True if MGCP request", HFILL }},
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{ &hf_mgcp_rsp,
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{ "Response", "mgcp.rsp", FT_BOOLEAN, BASE_NONE, NULL, 0x0,
|
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"TRUE if MGCP response", HFILL }},
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{ &hf_mgcp_req_frame,
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{ "Request Frame", "mgcp.reqframe", FT_FRAMENUM, BASE_NONE, NULL, 0,
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"Request Frame", HFILL }},
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{ &hf_mgcp_rsp_frame,
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{ "Response Frame", "mgcp.rspframe", FT_FRAMENUM, BASE_NONE, NULL, 0,
|
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"Response Frame", HFILL }},
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{ &hf_mgcp_time,
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{ "Time from request", "mgcp.time", FT_RELATIVE_TIME, BASE_NONE, NULL, 0,
|
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"Timedelta between Request and Response", HFILL }},
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{ &hf_mgcp_req_verb,
|
|
{ "Verb", "mgcp.req.verb", FT_STRING, BASE_DEC, NULL, 0x0,
|
|
"Name of the verb", HFILL }},
|
|
{ &hf_mgcp_req_endpoint,
|
|
{ "Endpoint", "mgcp.req.endpoint", FT_STRING, BASE_DEC, NULL, 0x0,
|
|
"Endpoint referenced by the message", HFILL }},
|
|
{ &hf_mgcp_transid,
|
|
{ "Transaction ID", "mgcp.transid", FT_STRING, BASE_DEC, NULL, 0x0,
|
|
"Transaction ID of this message", HFILL }},
|
|
{ &hf_mgcp_version,
|
|
{ "Version", "mgcp.version", FT_STRING, BASE_DEC, NULL, 0x0,
|
|
"MGCP Version", HFILL }},
|
|
{ &hf_mgcp_rsp_rspcode,
|
|
{ "Response Code", "mgcp.rsp.rspcode", FT_STRING, BASE_DEC, NULL, 0x0,
|
|
"Response Code", HFILL }},
|
|
{ &hf_mgcp_rsp_rspstring,
|
|
{ "Response String", "mgcp.rsp.rspstring", FT_STRING, BASE_DEC, NULL,
|
|
0x0, "Response String", HFILL }},
|
|
{ &hf_mgcp_param_rspack,
|
|
{ "ResponseAck (K)", "mgcp.param.rspack", FT_STRING, BASE_DEC, NULL,
|
|
0x0, "Response Ack", HFILL }},
|
|
{ &hf_mgcp_param_bearerinfo,
|
|
{ "BearerInformation (B)", "mgcp.param.bearerinfo", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Bearer Information", HFILL }},
|
|
{ &hf_mgcp_param_callid,
|
|
{ "CallId (C)", "mgcp.param.callid", FT_STRING, BASE_DEC, NULL, 0x0,
|
|
"Call Id", HFILL }},
|
|
{ &hf_mgcp_param_connectionid,
|
|
{"ConnectionIdentifier (I)", "mgcp.param.connectionid", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Connection Identifier", HFILL }},
|
|
{ &hf_mgcp_param_secondconnectionid,
|
|
{ "SecondConnectionID (I2)", "mgcp.param.secondconnectionid", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Second Connection Identifier", HFILL }},
|
|
{ &hf_mgcp_param_notifiedentity,
|
|
{ "NotifiedEntity (N)", "mgcp.param.notifiedentity", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Notified Entity", HFILL }},
|
|
{ &hf_mgcp_param_requestid,
|
|
{ "RequestIdentifier (X)", "mgcp.param.requestid", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Request Identifier", HFILL }},
|
|
{ &hf_mgcp_param_localconnoptions,
|
|
{ "LocalConnectionOptions (L)", "mgcp.param.localconnectionoptions",
|
|
FT_STRING, BASE_DEC, NULL, 0x0, "Local Connection Options", HFILL }},
|
|
{ &hf_mgcp_param_connectionmode,
|
|
{ "ConnectionMode (M)", "mgcp.param.connectionmode", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Connection Mode", HFILL }},
|
|
{ &hf_mgcp_param_reqevents,
|
|
{ "RequestedEvents (R)", "mgcp.param.reqevents", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Requested Events", HFILL }},
|
|
{ &hf_mgcp_param_signalreq,
|
|
{ "SignalRequests (S)", "mgcp.param.signalreq", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Signal Request", HFILL }},
|
|
{ &hf_mgcp_param_restartmethod,
|
|
{ "RestartMethod (RM)", "mgcp.param.restartmethod", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Restart Method", HFILL }},
|
|
{ &hf_mgcp_param_restartdelay,
|
|
{ "RestartDelay (RD)", "mgcp.param.restartdelay", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Restart Delay", HFILL }},
|
|
{ &hf_mgcp_param_digitmap,
|
|
{ "DigitMap (D)", "mgcp.param.digitmap", FT_STRING, BASE_DEC, NULL, 0x0,
|
|
"Digit Map", HFILL }},
|
|
{ &hf_mgcp_param_observedevent,
|
|
{ "ObservedEvents (O)", "mgcp.param.observedevents", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Observed Events", HFILL }},
|
|
{ &hf_mgcp_param_connectionparam,
|
|
{ "ConnectionParameters (P)", "mgcp.param.connectionparam", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Connection Parameters", HFILL }},
|
|
{ &hf_mgcp_param_reasoncode,
|
|
{ "ReasonCode (E)", "mgcp.param.reasoncode", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Reason Code", HFILL }},
|
|
{ &hf_mgcp_param_eventstates,
|
|
{ "EventStates (ES)", "mgcp.param.eventstates", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Event States", HFILL }},
|
|
{ &hf_mgcp_param_specificendpoint,
|
|
{ "SpecificEndpointID (Z)", "mgcp.param.specificendpointid", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Specific Endpoint ID", HFILL }},
|
|
{ &hf_mgcp_param_secondendpointid,
|
|
{ "SecondEndpointID (Z2)", "mgcp.param.secondendpointid", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Second Endpoing ID", HFILL }},
|
|
{ &hf_mgcp_param_reqinfo,
|
|
{ "RequestedInfo (F)", "mgcp.param.reqinfo", FT_STRING, BASE_DEC,
|
|
NULL, 0x0,"Requested Info", HFILL }},
|
|
{ &hf_mgcp_param_quarantinehandling,
|
|
{ "QuarantineHandling (Q)", "mgcp.param.quarantinehandling", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Quarantine Handling", HFILL }},
|
|
{ &hf_mgcp_param_detectedevents,
|
|
{ "DetectedEvents (T)", "mgcp.param.detectedevents", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Detected Events", HFILL }},
|
|
{ &hf_mgcp_param_capabilities,
|
|
{ "Capabilities (A)", "mgcp.param.capabilities", FT_STRING, BASE_DEC,
|
|
NULL, 0x0, "Capabilities", HFILL }},
|
|
{ &hf_mgcp_param_extention,
|
|
{ "Extention Parameter (X-*)", "mgcp.param.extention", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Extension Parameter", HFILL }},
|
|
{ &hf_mgcp_param_invalid,
|
|
{ "Invalid Parameter", "mgcp.param.invalid", FT_STRING,
|
|
BASE_DEC, NULL, 0x0, "Invalid Parameter", HFILL }},
|
|
{ &hf_mgcp_messagecount,
|
|
{ "MGCP Message Count", "mgcp.messagecount", FT_UINT32,
|
|
BASE_DEC, NULL, 0x0, "Number of MGCP message in a packet", HFILL }},
|
|
{ &hf_mgcp_dup,
|
|
{ "Duplicate Message", "mgcp.dup", FT_UINT32, BASE_DEC,
|
|
NULL, 0, "Duplicate Message", HFILL }},
|
|
{ &hf_mgcp_req_dup,
|
|
{ "Duplicate Request", "mgcp.req.dup", FT_UINT32, BASE_DEC,
|
|
NULL, 0, "Duplicate Request", HFILL }},
|
|
{ &hf_mgcp_rsp_dup,
|
|
{ "Duplicate Response", "mgcp.rsp.dup", FT_UINT32, BASE_DEC,
|
|
NULL, 0, "Duplicate Response", HFILL }},
|
|
/* Add more fields here */
|
|
};
|
|
static gint *ett[] = {
|
|
&ett_mgcp,
|
|
&ett_mgcp_param,
|
|
};
|
|
module_t *mgcp_module;
|
|
|
|
proto_mgcp = proto_register_protocol("Media Gateway Control Protocol",
|
|
"MGCP", "mgcp");
|
|
|
|
proto_register_field_array(proto_mgcp, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
register_init_routine(&mgcp_init_protocol);
|
|
|
|
/* Register our configuration options for , particularly our ports */
|
|
|
|
mgcp_module = prefs_register_protocol(proto_mgcp, proto_reg_handoff_mgcp);
|
|
|
|
prefs_register_uint_preference(mgcp_module, "tcp.gateway_port",
|
|
"MGCP Gateway TCP Port",
|
|
"Set the UDP port for gateway messages "
|
|
"(if other than the default of 2427)",
|
|
10, &global_mgcp_gateway_tcp_port);
|
|
|
|
prefs_register_uint_preference(mgcp_module, "udp.gateway_port",
|
|
"MGCP Gateway UDP Port",
|
|
"Set the TCP port for gateway messages "
|
|
"(if other than the default of 2427)",
|
|
10, &global_mgcp_gateway_udp_port);
|
|
|
|
prefs_register_uint_preference(mgcp_module, "tcp.callagent_port",
|
|
"MGCP Callagent TCP Port",
|
|
"Set the TCP port for callagent messages "
|
|
"(if other than the default of 2727)",
|
|
10, &global_mgcp_callagent_tcp_port);
|
|
|
|
prefs_register_uint_preference(mgcp_module, "udp.callagent_port",
|
|
"MGCP Callagent UDP Port",
|
|
"Set the UDP port for callagent messages "
|
|
"(if other than the default of 2727)",
|
|
10, &global_mgcp_callagent_udp_port);
|
|
|
|
|
|
prefs_register_bool_preference(mgcp_module, "display_raw_text",
|
|
"Display raw text for MGCP message",
|
|
"Specifies that the raw text of the "
|
|
"MGCP message should be displayed "
|
|
"instead of (or in addition to) the "
|
|
"dissection tree",
|
|
&global_mgcp_raw_text);
|
|
|
|
prefs_register_bool_preference(mgcp_module, "display_dissect_tree",
|
|
"Display tree dissection for MGCP message",
|
|
"Specifies that the dissection tree of the "
|
|
"MGCP message should be displayed "
|
|
"instead of (or in addition to) the "
|
|
"raw text",
|
|
&global_mgcp_dissect_tree);
|
|
|
|
prefs_register_bool_preference(mgcp_module, "display_mgcp_message_count",
|
|
"Display the number of MGCP messages",
|
|
"Display the number of MGCP messages "
|
|
"found in a packet in the protocol column.",
|
|
&global_mgcp_message_count);
|
|
|
|
mgcp_tap = register_tap("mgcp");
|
|
}
|
|
|
|
/* The registration hand-off routine */
|
|
void
|
|
proto_reg_handoff_mgcp(void)
|
|
{
|
|
static int mgcp_prefs_initialized = FALSE;
|
|
static dissector_handle_t mgcp_handle;
|
|
|
|
/*
|
|
* Get a handle for the SDP dissector.
|
|
*/
|
|
sdp_handle = find_dissector("sdp");
|
|
|
|
if (!mgcp_prefs_initialized) {
|
|
mgcp_handle = create_dissector_handle(dissect_mgcp, proto_mgcp);
|
|
mgcp_prefs_initialized = TRUE;
|
|
}
|
|
else {
|
|
dissector_delete("tcp.port", gateway_tcp_port, mgcp_handle);
|
|
dissector_delete("udp.port", gateway_udp_port, mgcp_handle);
|
|
dissector_delete("tcp.port", callagent_tcp_port, mgcp_handle);
|
|
dissector_delete("udp.port", callagent_udp_port, mgcp_handle);
|
|
}
|
|
|
|
/* Set our port number for future use */
|
|
|
|
gateway_tcp_port = global_mgcp_gateway_tcp_port;
|
|
gateway_udp_port = global_mgcp_gateway_udp_port;
|
|
|
|
callagent_tcp_port = global_mgcp_callagent_tcp_port;
|
|
callagent_udp_port = global_mgcp_callagent_udp_port;
|
|
|
|
dissector_add("tcp.port", global_mgcp_gateway_tcp_port, mgcp_handle);
|
|
dissector_add("udp.port", global_mgcp_gateway_udp_port, mgcp_handle);
|
|
dissector_add("tcp.port", global_mgcp_callagent_tcp_port, mgcp_handle);
|
|
dissector_add("udp.port", global_mgcp_callagent_udp_port, mgcp_handle);
|
|
|
|
}
|
|
|
|
/*
|
|
* is_mgcp_verb - A function for determining whether there is a
|
|
* MGCP verb at offset in tvb
|
|
*
|
|
* Parameter:
|
|
* tvb - The tvbuff in which we are looking for an MGCP verb
|
|
* offset - The offset in tvb at which we are looking for a MGCP verb
|
|
* maxlength - The maximum distance from offset we may look for the
|
|
* characters that make up a MGCP verb.
|
|
*
|
|
* Return: TRUE if there is an MGCP verb at offset in tvb, otherwise FALSE
|
|
*/
|
|
|
|
static gboolean is_mgcp_verb(tvbuff_t *tvb, gint offset, gint maxlength){
|
|
int returnvalue = FALSE;
|
|
guint8 word[5];
|
|
|
|
if(( maxlength >= 4) && tvb_get_nstringz0(tvb,offset,sizeof(word),word)){
|
|
if (strncasecmp(word, "EPCF", 4) == 0 ||
|
|
strncasecmp(word, "CRCX", 4) == 0 ||
|
|
strncasecmp(word, "MDCX", 4) == 0 ||
|
|
strncasecmp(word, "DLCX", 4) == 0 ||
|
|
strncasecmp(word, "RQNT", 4) == 0 ||
|
|
strncasecmp(word, "NTFY", 4) == 0 ||
|
|
strncasecmp(word, "AUEP", 4) == 0 ||
|
|
strncasecmp(word, "AUCX", 4) == 0 ||
|
|
strncasecmp(word, "RSIP", 4) == 0 ||
|
|
(word[0] == 'X' && is_rfc2234_alpha(word[1]) && is_rfc2234_alpha(word[2]) &&
|
|
is_rfc2234_alpha(word[3]))
|
|
){
|
|
returnvalue = TRUE;
|
|
}
|
|
}
|
|
if( returnvalue && maxlength >= 5 &&
|
|
(word[0] = tvb_get_guint8(tvb,4)) != ' ' && word[0] != '\t'){
|
|
returnvalue = FALSE;
|
|
}
|
|
return returnvalue;
|
|
}
|
|
|
|
/*
|
|
* is_mgcp_rspcode - A function for determining whether something which
|
|
* looks roughly like a MGCP response code is at
|
|
* offset in tvb
|
|
*
|
|
* Parameters:
|
|
* tvb - The tvbuff in which we are looking for an MGCP response code
|
|
* offset - The offset in tvb at which we are looking for a MGCP response code
|
|
* maxlength - The maximum distance from offset we may look for the
|
|
* characters that make up a MGCP response code.
|
|
*
|
|
* Return: TRUE if there is an MGCP response code at offset in tvb,
|
|
* otherwise FALSE
|
|
*/
|
|
|
|
static gboolean is_mgcp_rspcode(tvbuff_t *tvb, gint offset, gint maxlength){
|
|
int returnvalue = FALSE;
|
|
guint8 word[4];
|
|
if(maxlength >= 3){
|
|
tvb_get_nstringz0(tvb,offset,sizeof(word),word);
|
|
if( isdigit(word[0]) &&
|
|
isdigit(word[1]) &&
|
|
isdigit(word[2])){
|
|
returnvalue = TRUE;
|
|
}
|
|
}
|
|
if( returnvalue && maxlength >= 4 &&
|
|
(word[0] = tvb_get_guint8(tvb,3)) != ' ' && word[0] != '\t'){
|
|
returnvalue = FALSE;
|
|
}
|
|
return returnvalue;
|
|
}
|
|
|
|
/*
|
|
* is_rfc2234_alpha - Indicates whether the character c is an alphabetical
|
|
* character. This function is used instead of
|
|
* isalpha because isalpha may deviate from the rfc2234
|
|
* definition of ALPHA in some locales.
|
|
*
|
|
* Parameter:
|
|
* c - The character being checked for being an alphabetical character.
|
|
*
|
|
* Return: TRUE if c is an upper or lower case alphabetical character,
|
|
* FALSE otherwise.
|
|
*/
|
|
|
|
static gboolean is_rfc2234_alpha(guint8 c){
|
|
int returnvalue = FALSE;
|
|
if(( c <= 'Z' && c >= 'A' ) || (c <= 'z' && c >= 'a')){
|
|
returnvalue = TRUE;
|
|
}
|
|
return returnvalue;
|
|
}
|
|
|
|
/*
|
|
* tvb_parse_param - Parse the MGCP param into a type and a value.
|
|
*
|
|
* Parameters:
|
|
* tvb - The tvbuff containing the MGCP param we are to parse.
|
|
* offset - The offset in tvb at which we will begin looking for a
|
|
* MGCP parameter to parse.
|
|
* len - The maximum distance from offset in tvb that we can look for
|
|
* an MGCP parameter to parse.
|
|
* hf - The place to write a pointer to the integer representing the
|
|
* header field associated with the MGCP parameter parsed.
|
|
*
|
|
* Returns: The offset in tvb where the value of the MGCP parameter
|
|
* begins.
|
|
*/
|
|
static gint tvb_parse_param(tvbuff_t* tvb, gint offset, gint len, int** hf){
|
|
gint returnvalue, tvb_current_offset,counter;
|
|
guint8 tempchar;
|
|
tvb_current_offset = offset;
|
|
returnvalue = -1;
|
|
*hf = NULL;
|
|
if(len > 0){
|
|
tempchar = tvb_get_guint8(tvb,tvb_current_offset);
|
|
switch(tempchar){
|
|
case 'K':
|
|
*hf = &hf_mgcp_param_rspack;
|
|
break;
|
|
case 'B':
|
|
*hf = &hf_mgcp_param_bearerinfo;
|
|
break;
|
|
case 'C':
|
|
*hf = &hf_mgcp_param_callid;
|
|
break;
|
|
case 'I':
|
|
tvb_current_offset++;
|
|
if(len > (tvb_current_offset - offset) &&
|
|
(tempchar = tvb_get_guint8(tvb,tvb_current_offset)) == ':'){
|
|
*hf = &hf_mgcp_param_connectionid;
|
|
tvb_current_offset--;
|
|
}
|
|
else if ( tempchar == '2'){
|
|
*hf = &hf_mgcp_param_secondconnectionid;
|
|
}
|
|
break;
|
|
case 'N':
|
|
*hf = &hf_mgcp_param_notifiedentity;
|
|
break;
|
|
case 'X':
|
|
tvb_current_offset++;
|
|
if(len > (tvb_current_offset - offset) &&
|
|
(tempchar = tvb_get_guint8(tvb,tvb_current_offset)) == ':'){
|
|
*hf = &hf_mgcp_param_requestid;
|
|
}
|
|
else if(len > (tvb_current_offset - offset) && (
|
|
(tempchar = tvb_get_guint8(tvb,tvb_current_offset)) == '-' ||
|
|
tempchar == '+')){
|
|
tvb_current_offset++;
|
|
for(counter = 1;(counter <= 6) && (len > (counter + tvb_current_offset
|
|
- offset))
|
|
&& ( is_rfc2234_alpha(tempchar =
|
|
tvb_get_guint8(tvb,
|
|
tvb_current_offset+counter))
|
|
|| isdigit(tempchar));counter++);
|
|
if(tempchar == ':'){
|
|
tvb_current_offset += counter;
|
|
*hf = &hf_mgcp_param_extention;
|
|
}
|
|
}
|
|
tvb_current_offset--;
|
|
break;
|
|
case 'L':
|
|
*hf = &hf_mgcp_param_localconnoptions;
|
|
break;
|
|
case 'M':
|
|
*hf = &hf_mgcp_param_connectionmode;
|
|
break;
|
|
case 'R':
|
|
tvb_current_offset++;
|
|
if(len > (tvb_current_offset - offset) &&
|
|
(tempchar = tvb_get_guint8(tvb,tvb_current_offset)) == ':'){
|
|
*hf = &hf_mgcp_param_reqevents;
|
|
tvb_current_offset--;
|
|
}
|
|
else if ( tempchar == 'M'){
|
|
*hf = &hf_mgcp_param_restartmethod;
|
|
}
|
|
else if ( tempchar == 'D'){
|
|
*hf = &hf_mgcp_param_restartdelay;
|
|
}
|
|
break;
|
|
case 'S':
|
|
*hf = &hf_mgcp_param_signalreq;
|
|
break;
|
|
case 'D':
|
|
*hf = &hf_mgcp_param_digitmap;
|
|
break;
|
|
case 'O':
|
|
*hf = &hf_mgcp_param_observedevent;
|
|
break;
|
|
case 'P':
|
|
*hf = &hf_mgcp_param_connectionparam;
|
|
break;
|
|
case 'E':
|
|
tvb_current_offset++;
|
|
if(len > (tvb_current_offset - offset) &&
|
|
(tempchar = tvb_get_guint8(tvb,tvb_current_offset)) == ':'){
|
|
*hf = &hf_mgcp_param_reasoncode;
|
|
tvb_current_offset--;
|
|
}
|
|
else if ( tempchar == 'S'){
|
|
*hf = &hf_mgcp_param_eventstates;
|
|
}
|
|
break;
|
|
case 'Z':
|
|
tvb_current_offset++;
|
|
if(len > (tvb_current_offset - offset) &&
|
|
(tempchar = tvb_get_guint8(tvb,tvb_current_offset)) == ':'){
|
|
*hf = &hf_mgcp_param_specificendpoint;
|
|
tvb_current_offset--;
|
|
}
|
|
else if ( tempchar == '2'){
|
|
*hf = &hf_mgcp_param_secondendpointid;
|
|
}
|
|
break;
|
|
case 'F':
|
|
*hf = &hf_mgcp_param_reqinfo;
|
|
break;
|
|
|
|
case 'Q':
|
|
*hf = &hf_mgcp_param_quarantinehandling;
|
|
break;
|
|
|
|
case 'T':
|
|
*hf = &hf_mgcp_param_detectedevents;
|
|
break;
|
|
|
|
case 'A':
|
|
*hf = &hf_mgcp_param_capabilities;
|
|
break;
|
|
default:
|
|
*hf = &hf_mgcp_param_invalid;
|
|
break;
|
|
}
|
|
|
|
tvb_current_offset++;
|
|
if(*hf != NULL && len > (tvb_current_offset - offset) &&
|
|
(tempchar = tvb_get_guint8(tvb,tvb_current_offset)) == ':'){
|
|
tvb_current_offset++;
|
|
tvb_current_offset = tvb_skip_wsp(tvb,tvb_current_offset,
|
|
(len - tvb_current_offset + offset));
|
|
returnvalue = tvb_current_offset;
|
|
}
|
|
else {
|
|
*hf = &hf_mgcp_param_invalid;
|
|
}
|
|
}
|
|
else{
|
|
*hf = &hf_mgcp_param_invalid;
|
|
}
|
|
if(*hf == &hf_mgcp_param_invalid){
|
|
returnvalue = offset;
|
|
}
|
|
return returnvalue;
|
|
}
|
|
|
|
|
|
/*
|
|
* dissect_mgcp_firstline - Dissects the firstline of an MGCP message.
|
|
* Adds the appropriate headers fields to
|
|
* tree for the dissection of the first line
|
|
* of an MGCP message.
|
|
*
|
|
* Parameters:
|
|
* tvb - The tvb containing the first line of an MGCP message. This
|
|
* tvb is presumed to ONLY contain the first line of the MGCP
|
|
* message.
|
|
* pinfo - The packet info for the packet. This is not really used
|
|
* by this function but is passed through so as to retain the
|
|
* style of a dissector.
|
|
* tree - The tree from which to hang the structured information parsed
|
|
* from the first line of the MGCP message.
|
|
*/
|
|
static void dissect_mgcp_firstline(tvbuff_t *tvb, packet_info *pinfo,
|
|
proto_tree *tree, mgcp_info_t *mi){
|
|
gint tvb_current_offset,tvb_previous_offset,tvb_len,tvb_current_len;
|
|
gint tokennum, tokenlen;
|
|
char *transid = NULL;
|
|
char *code = NULL;
|
|
mgcp_type_t mgcp_type = MGCP_OTHERS;
|
|
conversation_t* conversation;
|
|
mgcp_call_info_key mgcp_call_key;
|
|
mgcp_call_info_key *new_mgcp_call_key = NULL;
|
|
mgcp_call_t *mgcp_call = NULL;
|
|
nstime_t delta;
|
|
|
|
static address null_address = { AT_NONE, 0, NULL };
|
|
proto_item* (*my_proto_tree_add_string)(proto_tree*, int, tvbuff_t*, gint,
|
|
gint, const char*);
|
|
tvb_previous_offset = 0;
|
|
tvb_len = tvb_length(tvb);
|
|
tvb_current_len = tvb_len;
|
|
tvb_current_offset = tvb_previous_offset;
|
|
mi->is_duplicate = FALSE;
|
|
mi->request_available = FALSE;
|
|
|
|
if(tree){
|
|
tokennum = 0;
|
|
|
|
if(global_mgcp_dissect_tree){
|
|
my_proto_tree_add_string = proto_tree_add_string;
|
|
}
|
|
else{
|
|
my_proto_tree_add_string = proto_tree_add_string_hidden;
|
|
}
|
|
|
|
do {
|
|
tvb_current_len = tvb_length_remaining(tvb,tvb_previous_offset);
|
|
tvb_current_offset = tvb_find_guint8(tvb, tvb_previous_offset,
|
|
tvb_current_len, ' ');
|
|
if(tvb_current_offset == -1){
|
|
tvb_current_offset = tvb_len;
|
|
tokenlen = tvb_current_len;
|
|
}
|
|
else{
|
|
tokenlen = tvb_current_offset - tvb_previous_offset;
|
|
}
|
|
if(tokennum == 0){
|
|
code = tvb_format_text(tvb,tvb_previous_offset,tokenlen);
|
|
strncpy(mi->code,code,4);
|
|
mi->code[4] = '\0';
|
|
if(is_mgcp_verb(tvb,tvb_previous_offset,tvb_current_len)){
|
|
mgcp_type = MGCP_REQUEST;
|
|
my_proto_tree_add_string(tree,hf_mgcp_req_verb, tvb,
|
|
tvb_previous_offset, tokenlen,
|
|
code);
|
|
}
|
|
else if (is_mgcp_rspcode(tvb,tvb_previous_offset,tvb_current_len)){
|
|
mgcp_type = MGCP_RESPONSE;
|
|
my_proto_tree_add_string(tree,hf_mgcp_rsp_rspcode, tvb,
|
|
tvb_previous_offset, tokenlen,
|
|
code);
|
|
}
|
|
else {
|
|
break;
|
|
}
|
|
}
|
|
if(tokennum == 1){
|
|
transid = tvb_format_text(tvb,tvb_previous_offset,tokenlen);
|
|
/* XXX - what if this isn't a valid text string? */
|
|
mi->transid = atol(transid);
|
|
my_proto_tree_add_string(tree,hf_mgcp_transid, tvb,
|
|
tvb_previous_offset, tokenlen,
|
|
transid);
|
|
}
|
|
if(tokennum == 2){
|
|
if(mgcp_type == MGCP_REQUEST){
|
|
my_proto_tree_add_string(tree,hf_mgcp_req_endpoint, tvb,
|
|
tvb_previous_offset, tokenlen,
|
|
tvb_format_text(tvb, tvb_previous_offset,
|
|
tokenlen));
|
|
}
|
|
else if(mgcp_type == MGCP_RESPONSE){
|
|
if(tvb_current_offset < tvb_len){
|
|
tokenlen = tvb_find_line_end(tvb, tvb_previous_offset,
|
|
-1,&tvb_current_offset,FALSE);
|
|
}
|
|
else{
|
|
tokenlen = tvb_current_len;
|
|
}
|
|
my_proto_tree_add_string(tree, hf_mgcp_rsp_rspstring, tvb,
|
|
tvb_previous_offset, tokenlen,
|
|
tvb_format_text(tvb, tvb_previous_offset,
|
|
tokenlen));
|
|
break;
|
|
}
|
|
}
|
|
if( (tokennum == 3 && mgcp_type == MGCP_REQUEST) ){
|
|
if(tvb_current_offset < tvb_len ){
|
|
tokenlen = tvb_find_line_end(tvb, tvb_previous_offset,
|
|
-1,&tvb_current_offset,FALSE);
|
|
}
|
|
else{
|
|
tokenlen = tvb_current_len;
|
|
}
|
|
my_proto_tree_add_string(tree,hf_mgcp_version, tvb,
|
|
tvb_previous_offset, tokenlen,
|
|
tvb_format_text(tvb,tvb_previous_offset,
|
|
tokenlen));
|
|
break;
|
|
}
|
|
if(tvb_current_offset < tvb_len){
|
|
tvb_previous_offset = tvb_skip_wsp(tvb, tvb_current_offset,
|
|
tvb_current_len);
|
|
}
|
|
tokennum++;
|
|
} while( tvb_current_offset < tvb_len && tvb_previous_offset < tvb_len
|
|
&& tokennum <= 3);
|
|
|
|
switch (mgcp_type){
|
|
case MGCP_RESPONSE:
|
|
proto_tree_add_boolean_hidden(tree, hf_mgcp_rsp, tvb, 0, 0, TRUE);
|
|
/* Check for MGCP response. A response must match a call that
|
|
we've seen, and the response must be sent to the same
|
|
port and address that the call came from, and must
|
|
come from the port to which the call was sent.
|
|
|
|
If the transport is connection-oriented (we check, for
|
|
now, only for "pinfo->ptype" of PT_TCP), we take
|
|
into account the address from which the call was sent
|
|
and the address to which the call was sent, because
|
|
the addresses of the two endpoints should be the same
|
|
for all calls and replies.
|
|
|
|
If the transport is connectionless, we don't worry
|
|
about the address to which the call was sent and from
|
|
which the reply was sent, because there's no
|
|
guarantee that the reply will come from the address
|
|
to which the call was sent. */
|
|
if (pinfo->ptype == PT_TCP) {
|
|
conversation = find_conversation(&pinfo->src,
|
|
&pinfo->dst, pinfo->ptype, pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
} else {
|
|
/*
|
|
* XXX - can we just use NO_ADDR_B? Unfortunately,
|
|
* you currently still have to pass a non-null
|
|
* pointer for the second address argument even
|
|
* if you do that.
|
|
*/
|
|
conversation = find_conversation(&null_address,
|
|
&pinfo->dst, pinfo->ptype, pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
}
|
|
if (conversation != NULL) {
|
|
/* look only for matching request, if
|
|
matching conversation is available. */
|
|
mgcp_call_key.transid = mi->transid;
|
|
mgcp_call_key.conversation = conversation;
|
|
mgcp_call = g_hash_table_lookup(mgcp_calls, &mgcp_call_key);
|
|
if(mgcp_call) {
|
|
/* Indicate the frame to which this is a reply. */
|
|
if(mgcp_call->req_num){
|
|
mi->request_available = TRUE;
|
|
mgcp_call->responded = TRUE;
|
|
strcpy(mi->code,mgcp_call->code);
|
|
proto_tree_add_uint_format(tree, hf_mgcp_req_frame,
|
|
tvb, 0, 0, mgcp_call->req_num,
|
|
"This is a response to a request in frame %u",
|
|
mgcp_call->req_num);
|
|
delta.secs= pinfo->fd->abs_secs-mgcp_call->req_time.secs;
|
|
delta.nsecs=pinfo->fd->abs_usecs*1000-mgcp_call->req_time.nsecs;
|
|
if(delta.nsecs<0){
|
|
delta.nsecs+=1000000000;
|
|
delta.secs--;
|
|
}
|
|
proto_tree_add_time(tree, hf_mgcp_time, tvb, 0, 0,
|
|
&delta);
|
|
}
|
|
|
|
if (mgcp_call->rsp_num == 0) {
|
|
/* We have not yet seen a response to that call, so
|
|
this must be the first response; remember its
|
|
frame number. */
|
|
mgcp_call->rsp_num = pinfo->fd->num;
|
|
} else {
|
|
/* We have seen a response to this call - but was it
|
|
*this* response? */
|
|
if (mgcp_call->rsp_num != pinfo->fd->num) {
|
|
/* No, so it's a duplicate response.
|
|
Mark it as such. */
|
|
mi->is_duplicate = TRUE;
|
|
if (check_col(pinfo->cinfo, COL_INFO)) {
|
|
col_append_fstr(pinfo->cinfo, COL_INFO,
|
|
", Duplicate Response %u",mi->transid);
|
|
if (tree) {
|
|
proto_tree_add_uint_hidden(tree,
|
|
hf_mgcp_dup, tvb, 0,0, mi->transid);
|
|
proto_tree_add_uint_hidden(tree,
|
|
hf_mgcp_rsp_dup, tvb, 0,0, mi->transid);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
case MGCP_REQUEST:
|
|
proto_tree_add_boolean_hidden(tree, hf_mgcp_req, tvb, 0, 0, TRUE);
|
|
/* Keep track of the address and port whence the call came,
|
|
and the port to which the call is being sent, so that
|
|
we can match up calls with replies.
|
|
|
|
If the transport is connection-oriented (we check, for
|
|
now, only for "pinfo->ptype" of PT_TCP), we take
|
|
into account the address from which the call was sent
|
|
and the address to which the call was sent, because
|
|
the addresses of the two endpoints should be the same
|
|
for all calls and replies.
|
|
|
|
If the transport is connectionless, we don't worry
|
|
about the address to which the call was sent and from
|
|
which the reply was sent, because there's no
|
|
guarantee that the reply will come from the address
|
|
to which the call was sent. */
|
|
if (pinfo->ptype == PT_TCP) {
|
|
conversation = find_conversation(&pinfo->src,
|
|
&pinfo->dst, pinfo->ptype, pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
} else {
|
|
/*
|
|
* XXX - can we just use NO_ADDR_B? Unfortunately,
|
|
* you currently still have to pass a non-null
|
|
* pointer for the second address argument even
|
|
* if you do that.
|
|
*/
|
|
conversation = find_conversation(&pinfo->src,
|
|
&null_address, pinfo->ptype, pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
}
|
|
if (conversation == NULL) {
|
|
/* It's not part of any conversation - create a new
|
|
one. */
|
|
if (pinfo->ptype == PT_TCP) {
|
|
conversation = conversation_new(&pinfo->src,
|
|
&pinfo->dst, pinfo->ptype, pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
} else {
|
|
conversation = conversation_new(&pinfo->src,
|
|
&null_address, pinfo->ptype, pinfo->srcport,
|
|
pinfo->destport, 0);
|
|
}
|
|
}
|
|
|
|
/* prepare the key data */
|
|
mgcp_call_key.transid = mi->transid;
|
|
mgcp_call_key.conversation = conversation;
|
|
|
|
/* look up the request */
|
|
mgcp_call = g_hash_table_lookup(mgcp_calls, &mgcp_call_key);
|
|
if (mgcp_call != NULL) {
|
|
/* We've seen a request with this TRANSID, with the same
|
|
source and destination, before - but was it
|
|
*this* request? */
|
|
if (pinfo->fd->num != mgcp_call->req_num) {
|
|
/* No, so it's a duplicate request.
|
|
Mark it as such. */
|
|
mi->is_duplicate = TRUE;
|
|
if (check_col(pinfo->cinfo, COL_INFO)) {
|
|
col_append_fstr(pinfo->cinfo, COL_INFO,
|
|
", Duplicate Request %u",mi->transid);
|
|
if (tree) {
|
|
proto_tree_add_uint_hidden(tree,
|
|
hf_mgcp_dup, tvb, 0,0, mi->transid);
|
|
proto_tree_add_uint_hidden(tree,
|
|
hf_mgcp_req_dup, tvb, 0,0, mi->transid);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
/* Prepare the value data.
|
|
"req_num" and "rsp_num" are frame numbers;
|
|
frame numbers are 1-origin, so we use 0
|
|
to mean "we don't yet know in which frame
|
|
the reply for this call appears". */
|
|
new_mgcp_call_key = g_mem_chunk_alloc(mgcp_call_info_key_chunk);
|
|
*new_mgcp_call_key = mgcp_call_key;
|
|
mgcp_call = g_mem_chunk_alloc(mgcp_call_info_value_chunk);
|
|
mgcp_call->req_num = pinfo->fd->num;
|
|
mgcp_call->rsp_num = 0;
|
|
mgcp_call->transid = mi->transid;
|
|
mgcp_call->responded = FALSE;
|
|
mgcp_call->req_time.secs=pinfo->fd->abs_secs;
|
|
mgcp_call->req_time.nsecs=pinfo->fd->abs_usecs*1000;
|
|
strcpy(mgcp_call->code,mi->code);
|
|
|
|
/* store it */
|
|
g_hash_table_insert(mgcp_calls, new_mgcp_call_key, mgcp_call);
|
|
}
|
|
if(mgcp_call && mgcp_call->rsp_num){
|
|
proto_tree_add_uint_format(tree, hf_mgcp_rsp_frame,
|
|
tvb, 0, 0, mgcp_call->rsp_num,
|
|
"The response to this request is in frame %u",
|
|
mgcp_call->rsp_num);
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
mi->mgcp_type = mgcp_type;
|
|
if(mgcp_call) {
|
|
mi->req_time.secs=mgcp_call->req_time.secs;
|
|
mi->req_time.nsecs=mgcp_call->req_time.nsecs;
|
|
}
|
|
}
|
|
tap_queue_packet(mgcp_tap, pinfo, mi);
|
|
}
|
|
|
|
/*
|
|
* dissect_mgcp_params - Dissects the parameters of an MGCP message.
|
|
* Adds the appropriate headers fields to
|
|
* tree for the dissection of the parameters
|
|
* of an MGCP message.
|
|
*
|
|
* Parameters:
|
|
* tvb - The tvb containing the parameters of an MGCP message. This
|
|
* tvb is presumed to ONLY contain the part of the MGCP
|
|
* message which contains the MGCP parameters.
|
|
* pinfo - The packet info for the packet. This is not really used
|
|
* by this function but is passed through so as to retain the
|
|
* style of a dissector.
|
|
* tree - The tree from which to hang the structured information parsed
|
|
* from the parameters of the MGCP message.
|
|
*/
|
|
static void dissect_mgcp_params(tvbuff_t *tvb, proto_tree *tree){
|
|
int linelen, tokenlen, *my_param;
|
|
gint tvb_lineend,tvb_current_len, tvb_linebegin,tvb_len;
|
|
gint tvb_tokenbegin;
|
|
proto_tree *mgcp_param_ti, *mgcp_param_tree;
|
|
proto_item* (*my_proto_tree_add_string)(proto_tree*, int, tvbuff_t*, gint,
|
|
gint, const char*);
|
|
|
|
tvb_len = tvb_length(tvb);
|
|
tvb_linebegin = 0;
|
|
tvb_current_len = tvb_length_remaining(tvb,tvb_linebegin);
|
|
tvb_lineend = tvb_linebegin;
|
|
|
|
if(tree){
|
|
if(global_mgcp_dissect_tree){
|
|
my_proto_tree_add_string = proto_tree_add_string;
|
|
mgcp_param_ti = proto_tree_add_item(tree, proto_mgcp, tvb,
|
|
tvb_linebegin, tvb_len, FALSE);
|
|
proto_item_set_text(mgcp_param_ti, "Parameters");
|
|
mgcp_param_tree = proto_item_add_subtree(mgcp_param_ti, ett_mgcp_param);
|
|
}
|
|
else{
|
|
my_proto_tree_add_string = proto_tree_add_string_hidden;
|
|
mgcp_param_tree = tree;
|
|
mgcp_param_ti = NULL;
|
|
}
|
|
|
|
/* Parse the parameters */
|
|
while(tvb_lineend < tvb_len){
|
|
linelen = tvb_find_line_end(tvb, tvb_linebegin, -1,&tvb_lineend,FALSE);
|
|
tvb_tokenbegin = tvb_parse_param(tvb, tvb_linebegin, linelen,
|
|
&my_param);
|
|
if( my_param != NULL ){
|
|
tokenlen = tvb_find_line_end(tvb,tvb_tokenbegin,-1,&tvb_lineend,FALSE);
|
|
my_proto_tree_add_string(mgcp_param_tree,*my_param, tvb,
|
|
tvb_linebegin, linelen,
|
|
tvb_format_text(tvb,tvb_tokenbegin,
|
|
tokenlen));
|
|
}
|
|
tvb_linebegin = tvb_lineend;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* tvb_skip_wsp - Returns the position in tvb of the first non-whitespace
|
|
* character following offset or offset + maxlength -1 whichever
|
|
* is smaller.
|
|
*
|
|
* Parameters:
|
|
* tvb - The tvbuff in which we are skipping whitespace.
|
|
* offset - The offset in tvb from which we begin trying to skip whitespace.
|
|
* maxlength - The maximum distance from offset that we may try to skip
|
|
* whitespace.
|
|
*
|
|
* Returns: The position in tvb of the first non-whitespace
|
|
* character following offset or offset + maxlength -1 whichever
|
|
* is smaller.
|
|
*/
|
|
static gint tvb_skip_wsp(tvbuff_t* tvb, gint offset, gint maxlength){
|
|
gint counter = offset;
|
|
gint end = offset + maxlength,tvb_len;
|
|
guint8 tempchar;
|
|
tvb_len = tvb_length(tvb);
|
|
end = offset + maxlength;
|
|
if(end >= tvb_len){
|
|
end = tvb_len;
|
|
}
|
|
for(counter = offset; counter < end &&
|
|
((tempchar = tvb_get_guint8(tvb,counter)) == ' ' ||
|
|
tempchar == '\t');counter++);
|
|
return (counter);
|
|
}
|
|
|
|
/*
|
|
* tvb_find_null_line - Returns the length from offset to the first null
|
|
* line found (a null line is a line that begins
|
|
* with a CR or LF. The offset to the first character
|
|
* after the null line is written into the gint pointed
|
|
* to by next_offset.
|
|
*
|
|
* Parameters:
|
|
* tvb - The tvbuff in which we are looking for a null line.
|
|
* offset - The offset in tvb at which we will begin looking for
|
|
* a null line.
|
|
* len - The maximum distance from offset in tvb that we will look for
|
|
* a null line. If it is -1 we will look to the end of the buffer.
|
|
*
|
|
* next_offset - The location to write the offset of first character
|
|
* FOLLOWING the null line.
|
|
*
|
|
* Returns: The length from offset to the first character BEFORE
|
|
* the null line..
|
|
*/
|
|
static gint tvb_find_null_line(tvbuff_t* tvb, gint offset,
|
|
gint len, gint* next_offset){
|
|
gint tvb_lineend,tvb_current_len,tvb_linebegin,maxoffset;
|
|
guint tempchar;
|
|
|
|
tvb_linebegin = offset;
|
|
tvb_lineend = tvb_linebegin;
|
|
|
|
/* Simple setup to allow for the traditional -1 search to the end
|
|
* of the tvbuff
|
|
*/
|
|
if(len != -1){
|
|
tvb_current_len = len;
|
|
}
|
|
else{
|
|
tvb_current_len = tvb_length_remaining(tvb,offset);
|
|
}
|
|
maxoffset = (tvb_current_len - 1) + offset;
|
|
|
|
/*
|
|
* Loop around until we either find a line begining with a carriage return
|
|
* or newline character or until we hit the end of the tvbuff.
|
|
*/
|
|
do {
|
|
tvb_linebegin = tvb_lineend;
|
|
tvb_current_len = tvb_length_remaining(tvb,tvb_linebegin);
|
|
tvb_find_line_end(tvb, tvb_linebegin, tvb_current_len, &tvb_lineend,FALSE);
|
|
tempchar = tvb_get_guint8(tvb,tvb_linebegin);
|
|
}
|
|
while( tempchar != '\r' && tempchar != '\n' &&
|
|
tvb_lineend <= maxoffset);
|
|
|
|
*next_offset = tvb_lineend;
|
|
|
|
if( tvb_lineend <= maxoffset ) {
|
|
tvb_current_len = tvb_linebegin - offset;
|
|
}
|
|
else {
|
|
tvb_current_len = tvb_length_remaining(tvb,offset);
|
|
}
|
|
|
|
return (tvb_current_len);
|
|
}
|
|
|
|
/*
|
|
* tvb_find_dot_line - Returns the length from offset to the first line
|
|
* containing only a dot (.) character. A line
|
|
* containing only a dot is used to indicate a
|
|
* separation between multiple MGCP messages
|
|
* piggybacked in the same UDP packet.
|
|
*
|
|
* Parameters:
|
|
* tvb - The tvbuff in which we are looking for a dot line.
|
|
* offset - The offset in tvb at which we will begin looking for
|
|
* a dot line.
|
|
* len - The maximum distance from offset in tvb that we will look for
|
|
* a dot line. If it is -1 we will look to the end of the buffer.
|
|
*
|
|
* next_offset - The location to write the offset of first character
|
|
* FOLLOWING the dot line.
|
|
*
|
|
* Returns: The length from offset to the first character BEFORE
|
|
* the dot line or -1 if the character at offset is a .
|
|
* followed by a newline or a carriage return.
|
|
*/
|
|
static gint tvb_find_dot_line(tvbuff_t* tvb, gint offset,
|
|
gint len, gint* next_offset){
|
|
gint tvb_current_offset, tvb_current_len, maxoffset,tvb_len;
|
|
guint8 tempchar;
|
|
|
|
tvb_current_offset = offset;
|
|
tvb_current_len = len;
|
|
tvb_len = tvb_length(tvb);
|
|
|
|
if(len == -1){
|
|
maxoffset = ( tvb_len - 1 );
|
|
}
|
|
else {
|
|
maxoffset = (len - 1 ) + offset;
|
|
}
|
|
tvb_current_offset = offset -1;
|
|
do {
|
|
tvb_current_offset = tvb_find_guint8(tvb, tvb_current_offset+1,
|
|
tvb_current_len, '.');
|
|
tvb_current_len = maxoffset - tvb_current_offset + 1;
|
|
/*
|
|
* if we didn't find a . then break out of the loop
|
|
*/
|
|
if(tvb_current_offset == -1){
|
|
break;
|
|
}
|
|
/* do we have and characters following the . ? */
|
|
if( tvb_current_offset < maxoffset ) {
|
|
tempchar = tvb_get_guint8(tvb,tvb_current_offset+1);
|
|
/*
|
|
* are the characters that follow the dot a newline or carriage return ?
|
|
*/
|
|
if(tempchar == '\r' || tempchar == '\n'){
|
|
/*
|
|
* do we have any charaters that proceed the . ?
|
|
*/
|
|
if( tvb_current_offset == 0 ){
|
|
break;
|
|
}
|
|
else {
|
|
tempchar = tvb_get_guint8(tvb,tvb_current_offset-1);
|
|
/*
|
|
* are the characters that follow the dot a newline or a carriage
|
|
* return ?
|
|
*/
|
|
if(tempchar == '\r' || tempchar == '\n'){
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else if ( tvb_current_offset == maxoffset ) {
|
|
if( tvb_current_offset == 0 ){
|
|
break;
|
|
}
|
|
else {
|
|
tempchar = tvb_get_guint8(tvb,tvb_current_offset-1);
|
|
if(tempchar == '\r' || tempchar == '\n'){
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
} while (tvb_current_offset < maxoffset);
|
|
/*
|
|
* so now we either have the tvb_current_offset of a . in a dot line
|
|
* or a tvb_current_offset of -1
|
|
*/
|
|
if(tvb_current_offset == -1){
|
|
tvb_current_offset = maxoffset +1;
|
|
*next_offset = maxoffset + 1;
|
|
}
|
|
else {
|
|
tvb_find_line_end(tvb,tvb_current_offset,tvb_current_len,next_offset,FALSE);
|
|
}
|
|
|
|
if( tvb_current_offset == offset ){
|
|
tvb_current_len = -1;
|
|
}
|
|
else {
|
|
tvb_current_len = tvb_current_offset - offset;
|
|
}
|
|
return tvb_current_len;
|
|
}
|
|
|
|
/* Start the functions we need for the plugin stuff */
|
|
|
|
#ifndef ENABLE_STATIC
|
|
|
|
G_MODULE_EXPORT void
|
|
plugin_reg_handoff(void){
|
|
proto_reg_handoff_mgcp();
|
|
}
|
|
|
|
G_MODULE_EXPORT void
|
|
plugin_init(plugin_address_table_t *pat
|
|
#ifndef PLUGINS_NEED_ADDRESS_TABLE
|
|
_U_
|
|
#endif
|
|
){
|
|
/* initialise the table of pointers needed in Win32 DLLs */
|
|
plugin_address_table_init(pat);
|
|
/* register the new protocol, protocol fields, and subtrees */
|
|
if (proto_mgcp == -1) { /* execute protocol initialization only once */
|
|
proto_register_mgcp();
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
/* End the functions we need for plugin stuff */
|