chan_mgcp.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Implementation of Media Gateway Control Protocol
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \par See also
 * \arg \ref Config_mgcp
 *
 * \ingroup channel_drivers
 */

/* FO: Changes
 * -- add distinctive ring signalling (part of RFC 3660)
 */

/* JS: Changes
   -- add support for the wildcard endpoint
   -- seteable wildcard with wcardep on mgcp.conf
   -- added package indicator on RQNT, i.e "dl" --> "L/dl"
   -- removed MDCX just before DLCX, do we need this ?
*/

/* JS: TODO
   -- reload for wildcard endpoint probably buggy
   -- when hf is notified we're sending CRCX after MDCX, without waiting for
      OK on the MDCX which fails on Cisco IAD 24XX
   -- honour codec order, by now the lowest codec number in "allow" is the prefered
*/

/* SC: Changes
   -- packet retransmit mechanism (simplistic)
   -- per endpoint/subchannel mgcp command sequencing. 
   -- better transaction handling
   -- fixed some mem leaks
   -- run-time configuration reload 
   -- distinguish CA and GW default MGCP ports
   -- prevent clipping of DTMF tones in an established call
   -- fixed a few crash scenarios in 3-way
   -- fix for a few cases where asterisk and MGW end-up in conflicting ep states 
   -- enclose numeric IP in [] for outgoing requests
*/

/* SC: TODO
   -- piggyback support
   -- responseAck support
   -- enhance retransmit mechanism (RTO calc. etc.)
   -- embedded command support
*/

/* FS: Changes
   -- fixed reload_config() / do_monitor to stay responsive during reloads
*/

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <errno.h>
#include <stdlib.h>
#include <fcntl.h>
#include <netdb.h>
#include <sys/signal.h>
#include <signal.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <ctype.h>

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/config.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/options.h"
#include "asterisk/lock.h"
#include "asterisk/sched.h"
#include "asterisk/io.h"
#include "asterisk/rtp.h"
#include "asterisk/acl.h"
#include "asterisk/callerid.h"
#include "asterisk/cli.h"
#include "asterisk/say.h"
#include "asterisk/cdr.h"
#include "asterisk/astdb.h"
#include "asterisk/features.h"
#include "asterisk/app.h"
#include "asterisk/musiconhold.h"
#include "asterisk/utils.h"
#include "asterisk/causes.h"
#include "asterisk/dsp.h"
#include "asterisk/devicestate.h"
#include "asterisk/stringfields.h"

#ifndef IPTOS_MINCOST
#define IPTOS_MINCOST 0x02
#endif

/*
 * Define to work around buggy dlink MGCP phone firmware which
 * appears not to know that "rt" is part of the "G" package.
 */
/* #define DLINK_BUGGY_FIRMWARE	*/

#define MGCPDUMPER
#define DEFAULT_EXPIRY	120
#define MAX_EXPIRY	3600
#define CANREINVITE	1

#ifndef INADDR_NONE
#define INADDR_NONE (in_addr_t)(-1)
#endif

static const char desc[] = "Media Gateway Control Protocol (MGCP)";
static const char tdesc[] = "Media Gateway Control Protocol (MGCP)";
static const char config[] = "mgcp.conf";

#define MGCP_DTMF_RFC2833	(1 << 0)
#define MGCP_DTMF_INBAND	(1 << 1)
#define MGCP_DTMF_HYBRID	(1 << 2)

#define DEFAULT_MGCP_GW_PORT	2427 /* From RFC 2705 */
#define DEFAULT_MGCP_CA_PORT	2727 /* From RFC 2705 */
#define MGCP_MAX_PACKET		1500 /* Also from RFC 2543, should sub headers tho */
#define DEFAULT_RETRANS		1000 /* How frequently to retransmit */
#define MAX_RETRANS		5    /* Try only 5 times for retransmissions */

/* MGCP rtp stream modes */
#define MGCP_CX_SENDONLY	0
#define MGCP_CX_RECVONLY	1
#define MGCP_CX_SENDRECV	2
#define MGCP_CX_CONF		3
#define MGCP_CX_CONFERENCE	3
#define MGCP_CX_MUTE		4
#define MGCP_CX_INACTIVE	4

static char *mgcp_cxmodes[] = {
	"sendonly",
	"recvonly",
	"sendrecv",
	"confrnce",
	"inactive"
};

/* SC: MGCP commands */
#define MGCP_CMD_EPCF 0
#define MGCP_CMD_CRCX 1
#define MGCP_CMD_MDCX 2
#define MGCP_CMD_DLCX 3
#define MGCP_CMD_RQNT 4
#define MGCP_CMD_NTFY 5
#define MGCP_CMD_AUEP 6
#define MGCP_CMD_AUCX 7
#define MGCP_CMD_RSIP 8

static char context[AST_MAX_EXTENSION] = "default";

static char language[MAX_LANGUAGE] = "";
static char musicclass[MAX_MUSICCLASS] = "";
static char cid_num[AST_MAX_EXTENSION] = "";
static char cid_name[AST_MAX_EXTENSION] = "";

static int dtmfmode = 0;
static int nat = 0;

/* Not used. Dosn't hurt for us to always send cid  */
/* to the mgcp box. */
/*static int use_callerid = 1;*/
/*static int cur_signalling = -1;*/

/*static unsigned int cur_group = 0;*/
static ast_group_t cur_callergroup = 0;
static ast_group_t cur_pickupgroup = 0;