chan_h323.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005
 *
 * OpenH323 Channel Driver for ASTERISK PBX.
 *			By Jeremy McNamara
 *                      For The NuFone Network 
 *
 * chan_h323 has been derived from code created by
 *               Michael Manousos and Mark Spencer
 *
 * 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 This file is part of the chan_h323 driver for Asterisk
 *
 * \author Jeremy McNamara
 *
 * \par See also
 * \arg Config_h323
 *
 * \ingroup channel_drivers
 */

#include <sys/socket.h>
#include <sys/signal.h>
#include <sys/param.h>
#if defined(BSD)
#ifndef IPTOS_MINCOST
#define IPTOS_MINCOST 0x02
#endif
#endif
#include <arpa/inet.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <unistd.h>
#include <stdlib.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#ifdef __cplusplus
extern "C" {
#endif   

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/lock.h"
#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/options.h"
#include "asterisk/utils.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/dsp.h"
#include "asterisk/causes.h"
#include "asterisk/stringfields.h"
#ifdef __cplusplus
}
#endif
#include "h323/chan_h323.h"

send_digit_cb on_send_digit; 
on_rtp_cb on_external_rtp_create; 
start_rtp_cb on_start_rtp_channel; 
setup_incoming_cb on_incoming_call;
setup_outbound_cb on_outgoing_call; 
chan_ringing_cb	on_chan_ringing;
con_established_cb on_connection_established;
clear_con_cb on_connection_cleared;
answer_call_cb on_answer_call;
progress_cb on_progress;
rfc2833_cb on_set_rfc2833_payload;
hangup_cb on_hangup;
setcapabilities_cb on_setcapabilities;

/* global debug flag */
int h323debug;

/** Variables required by Asterisk */
static const char desc[] = "The NuFone Network's Open H.323 Channel Driver";
static const char tdesc[] = "The NuFone Network's Open H.323 Channel Driver";
static const char config[] = "h323.conf";
static char default_context[AST_MAX_CONTEXT] = "default";
static struct sockaddr_in bindaddr;

#define GLOBAL_CAPABILITY (AST_FORMAT_G723_1 | AST_FORMAT_GSM | AST_FORMAT_ULAW | AST_FORMAT_ALAW | AST_FORMAT_G729A | AST_FORMAT_H261)

/** H.323 configuration values */
static int h323_signalling_port = 1720;
static char gatekeeper[100];
static int gatekeeper_disable = 1;
static int gatekeeper_discover = 0;
static int usingGk = 0;
static int gkroute = 0;
/* Find user by alias (h.323 id) is default, alternative is the incomming call's source IP address*/
static int userbyalias = 1;
static int tos = 0;
static char secret[50];
static unsigned int unique = 0;

static call_options_t global_options;

/** Private structure of a OpenH323 channel */
struct oh323_pvt {
	ast_mutex_t lock;					/* Channel private lock */
	call_options_t options;					/* Options to be used during call setup */
	int alreadygone;					/* Whether or not we've already been destroyed by our peer */
	int needdestroy;					/* if we need to be destroyed */
	call_details_t cd;					/* Call details */
	struct ast_channel *owner;				/* Who owns us */
	struct sockaddr_in sa;                  		/* Our peer */
	struct sockaddr_in redirip; 			        /* Where our RTP should be going if not to us */
	int nonCodecCapability;					/* non-audio capability */
	int outgoing;						/* Outgoing or incoming call? */
	char exten[AST_MAX_EXTENSION];				/* Requested extension */
	char context[AST_MAX_CONTEXT];				/* Context where to start */
	char accountcode[256];					/* Account code */
	char cid_num[80];					/* Caller*id number, if available */
	char cid_name[80];					/* Caller*id name, if available */
	char rdnis[80];						/* Referring DNIS, if available */
	int amaflags;						/* AMA Flags */
	struct ast_rtp *rtp;					/* RTP Session */
	struct ast_dsp *vad;					/* Used for in-band DTMF detection */
	int nativeformats;					/* Codec formats supported by a channel */
	int needhangup;						/* Send hangup when Asterisk is ready */
	int hangupcause;					/* Hangup cause from OpenH323 layer */
	int newstate;						/* Pending state change */
	int newcontrol;						/* Pending control to send */
	struct oh323_pvt *next;				/* Next channel in list */
} *iflist = NULL;

static struct ast_user_list {
	struct oh323_user *users;
	ast_mutex_t lock;
} userl;

static struct ast_peer_list {
	struct oh323_peer *peers;
	ast_mutex_t lock;
} peerl;

static struct ast_alias_list {
	struct oh323_alias *aliases;
	ast_mutex_t lock;
} aliasl;

/** Asterisk RTP stuff */
static struct sched_context *sched;
static struct io_context *io;

/** Protect the interface list (oh323_pvt) */
AST_MUTEX_DEFINE_STATIC(iflock);

/** Usage counter and associated lock */
static int usecnt = 0;
AST_MUTEX_DEFINE_STATIC(usecnt_lock);

/* Protect the monitoring thread, so only one process can kill or start it, and not
   when it's doing something critical. */
AST_MUTEX_DEFINE_STATIC(monlock);

/* Protect the H.323 capabilities list, to avoid more than one channel to set the capabilities simultaneaously in the h323 stack. */
AST_MUTEX_DEFINE_STATIC(caplock);

/* Protect the reload process */
AST_MUTEX_DEFINE_STATIC(h323_reload_lock);
static int h323_reloading = 0;

/* This is the thread for the monitor which checks for input on the channels
   which are not currently in use.  */
static pthread_t monitor_thread = AST_PTHREADT_NULL;
static int restart_monitor(void);
static int h323_do_reload(void);

static struct ast_channel *oh323_request(const char *type, int format, void *data, int *cause);
static int oh323_digit(struct ast_channel *c, char digit);
static int oh323_call(struct ast_channel *c, char *dest, int timeout);
static int oh323_hangup(struct ast_channel *c);
static int oh323_answer(struct ast_channel *c);
static struct ast_frame *oh323_read(struct ast_channel *c);
static int oh323_write(struct ast_channel *c, struct ast_frame *frame);
static int oh323_indicate(struct ast_channel *c, int condition);
static int oh323_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);

static const struct ast_channel_tech oh323_tech = {
	.type = "H323",
	.description = tdesc,
	.capabilities = ((AST_FORMAT_MAX_AUDIO << 1) - 1),
	.properties = AST_CHAN_TP_WANTSJITTER,
	.requester = oh323_request,
	.send_digit = oh323_digit,
	.call = oh323_call,
	.hangup = oh323_hangup,
	.answer = oh323_answer,
	.read = oh323_read,
	.write = oh323_write,
	.indicate = oh323_indicate,
	.fixup = oh323_fixup,
	/* disable, for now */
#if 0
	.bridge = ast_rtp_bridge,
#endif
};

/* Channel and private structures should be already locked */
static void __oh323_update_info(struct ast_channel *c, struct oh323_pvt *pvt)
{
	if (c->nativeformats != pvt->nativeformats) {
		if (h323debug)
			ast_log(LOG_DEBUG, "Preparing %s for new native format\n", c->name);
		c->nativeformats = pvt->nativeformats;
		ast_set_read_format(c, c->readformat);
		ast_set_write_format(c, c->writeformat);
	}
	if (pvt->needhangup) {
		if (h323debug)
			ast_log(LOG_DEBUG, "Process pending hangup for %s\n", c->name);
		c->_softhangup |= AST_SOFTHANGUP_DEV;
		c->hangupcause = pvt->hangupcause;
		ast_queue_hangup(c);
		pvt->needhangup = 0;
		pvt->newstate = pvt->newcontrol = -1;
	}
	if (pvt->newstate >= 0) {
		ast_setstate(c, pvt->newstate);
		pvt->newstate = -1;
	}
	if (pvt->newcontrol >= 0) {
		ast_queue_control(c, pvt->newcontrol);
		pvt->newcontrol = -1;
	}
}

/* Only channel structure should be locked */
static void oh323_update_info(struct ast_channel *c)
{
	struct oh323_pvt *pvt = c->tech_pvt;

	if (pvt) {
		ast_mutex_lock(&pvt->lock);
		__oh323_update_info(c, pvt);
		ast_mutex_unlock(&pvt->lock);
	}
}

static void cleanup_call_details(call_details_t *cd) 
{
        if (cd->call_token) {
                free(cd->call_token);
                cd->call_token = NULL;
        }
        if (cd->call_source_aliases) {
                free(cd->call_source_aliases);
                cd->call_source_aliases = NULL;
        }
        if (cd->call_dest_alias) {
                free(cd->call_dest_alias);
                cd->call_dest_alias = NULL;
	}
        if (cd->call_source_name) { 
                free(cd->call_source_name);
                cd->call_source_name = NULL;
        }
        if (cd->call_source_e164) {
                free(cd->call_source_e164);
                cd->call_source_e164 = NULL;
        }
        if (cd->call_dest_e164) {
                free(cd->call_dest_e164);
                cd->call_dest_e164 = NULL;
        }
        if (cd->sourceIp) {
                free(cd->sourceIp);
                cd->sourceIp = NULL;
        }
}

static void __oh323_destroy(struct oh323_pvt *pvt)
{
	struct oh323_pvt *cur, *prev = NULL;
	
	if (pvt->rtp) {
		ast_rtp_destroy(pvt->rtp);
	}
	
	/* Free dsp used for in-band DTMF detection */
	if (pvt->vad) {
		ast_dsp_free(pvt->vad);
	}
	cleanup_call_details(&pvt->cd);

	/* Unlink us from the owner if we have one */
	if (pvt->owner) {
		ast_mutex_lock(&pvt->owner->lock);
		ast_log(LOG_DEBUG, "Detaching from %s\n", pvt->owner->name);
		pvt->owner->tech_pvt = NULL;
		ast_mutex_unlock(&pvt->owner->lock);
	}
	cur = iflist;
	while(cur) {
		if (cur == pvt) {
			if (prev)
				prev->next = cur->next;
			else
				iflist = cur->next;
			break;
		}
		prev = cur;
		cur = cur->next;
	}
	if (!cur) {
		ast_log(LOG_WARNING, "%p is not in list?!?! \n", cur);
	} else {
		ast_mutex_destroy(&pvt->lock);
		free(pvt);
	}
}

static void oh323_destroy(struct oh323_pvt *pvt)
{
	ast_mutex_lock(&iflock);
	__oh323_destroy(pvt);
	ast_mutex_unlock(&iflock);
}

/**
 * Send (play) the specified digit to the channel.
 * 
 */
static int oh323_digit(struct ast_channel *c, char digit)
{
	struct oh323_pvt *pvt = (struct oh323_pvt *) c->tech_pvt;
	char *token;

	if (!pvt) {
		ast_log(LOG_ERROR, "No private structure?! This is bad\n");
		return -1;
	}
	ast_mutex_lock(&pvt->lock);
	if (pvt->rtp && (pvt->options.dtmfmode & H323_DTMF_RFC2833)) {
		/* out-of-band DTMF */
		if (h323debug) {
			ast_log(LOG_DEBUG, "Sending out-of-band digit %c on %s\n", digit, c->name);
		}
		ast_rtp_senddigit(pvt->rtp, digit);
	} else {
		/* in-band DTMF */
		if (h323debug) {
			ast_log(LOG_DEBUG, "Sending inband digit %c on %s\n", digit, c->name);
		}
		token = pvt->cd.call_token ? strdup(pvt->cd.call_token) : NULL;
		h323_send_tone(token, digit);
		if (token) {
			free(token);
		}
	}
	ast_mutex_unlock(&pvt->lock);
	oh323_update_info(c);
	return 0;
}

/**
 * Make a call over the specified channel to the specified 
 * destination.
 * Returns -1 on error, 0 on success.
 */
static int oh323_call(struct ast_channel *c, char *dest, int timeout)
{  
	int res = 0;
	struct oh323_pvt *pvt = (struct oh323_pvt *)c->tech_pvt;
	char addr[INET_ADDRSTRLEN];
	char called_addr[1024];

	if (h323debug) {
		ast_log(LOG_DEBUG, "Calling to %s on %s\n", dest, c->name);
	}
	if ((c->_state != AST_STATE_DOWN) && (c->_state != AST_STATE_RESERVED)) {
		ast_log(LOG_WARNING, "Line is already in use (%s)\n", c->name);
		return -1;
	}
	ast_mutex_lock(&pvt->lock);
	if (usingGk) {
		if (ast_strlen_zero(pvt->exten)) {
			strncpy(called_addr, dest, sizeof(called_addr));
		} else {
			snprintf(called_addr, sizeof(called_addr), "%s@%s", pvt->exten, dest);
		}
	} else {
		ast_inet_ntoa(addr, sizeof(addr), pvt->sa.sin_addr);
		res = htons(pvt->sa.sin_port);
		if (ast_strlen_zero(pvt->exten)) {
			snprintf(called_addr, sizeof(called_addr), "%s:%d", addr, res);
		} else {
			snprintf(called_addr, sizeof(called_addr), "%s@%s:%d", pvt->exten, addr, res);
		}
	}
	/* make sure null terminated */
	called_addr[sizeof(called_addr) - 1] = '\0'; 

	if (c->cid.cid_num) {
		strncpy(pvt->options.cid_num, c->cid.cid_num, sizeof(pvt->options.cid_num));
	}
	if (c->cid.cid_name) {
		strncpy(pvt->options.cid_name, c->cid.cid_name, sizeof(pvt->options.cid_name));
	}

	/* indicate that this is an outgoing call */
	pvt->outgoing = 1;

	ast_log(LOG_DEBUG, "Placing outgoing call to %s, %d\n", called_addr, pvt->options.dtmfcodec);
	ast_mutex_unlock(&pvt->lock);
	res = h323_make_call(called_addr, &(pvt->cd), &pvt->options);
	if (res) {
		ast_log(LOG_NOTICE, "h323_make_call failed(%s)\n", c->name);
		return -1;
	}
	oh323_update_info(c);
	return 0;
}

static int oh323_answer(struct ast_channel *c)
{
	int res;
	struct oh323_pvt *pvt = (struct oh323_pvt *) c->tech_pvt;
	char *token;

	if (h323debug)
		ast_log(LOG_DEBUG, "Answering on %s\n", c->name);

	ast_mutex_lock(&pvt->lock);
	token = pvt->cd.call_token ? strdup(pvt->cd.call_token) : NULL;
	ast_mutex_unlock(&pvt->lock);
	res = h323_answering_call(token, 0);
	if (token)
		free(token);

	oh323_update_info(c);
	if (c->_state != AST_STATE_UP) {
		ast_setstate(c, AST_STATE_UP);
	}
	return res;
}

static int oh323_hangup(struct ast_channel *c)
{
	struct oh323_pvt *pvt = (struct oh323_pvt *) c->tech_pvt;
	int needcancel = 0;
	int q931cause = AST_CAUSE_NORMAL_CLEARING;
	char *call_token;


	if (h323debug)
		ast_log(LOG_DEBUG, "Hanging up call %s\n", c->name);

	if (!c->tech_pvt) {
		ast_log(LOG_DEBUG, "Asked to hangup channel not connected\n");
		return 0;
	}
	ast_mutex_lock(&pvt->lock);
	/* Determine how to disconnect */
	if (pvt->owner != c) {
		ast_log(LOG_WARNING, "Huh?  We aren't the owner?\n");
		ast_mutex_unlock(&pvt->lock);
		return 0;
	}
	if (!c || (c->_state != AST_STATE_UP)) {
		needcancel = 1;
	}
	
	pvt->owner = NULL;
	c->tech_pvt = NULL;

	if (c->hangupcause) {
		q931cause = c->hangupcause;
	} else {
		const char *cause = pbx_builtin_getvar_helper(c, "DIALSTATUS");
		if (cause) {
			if (!strcmp(cause, "CONGESTION")) {
				q931cause = AST_CAUSE_NORMAL_CIRCUIT_CONGESTION;
			} else if (!strcmp(cause, "BUSY")) {
				q931cause = AST_CAUSE_USER_BUSY;
			} else if (!strcmp(cause, "CHANISUNVAIL")) {
				q931cause = AST_CAUSE_REQUESTED_CHAN_UNAVAIL;
			} else if (!strcmp(cause, "NOANSWER")) {
				q931cause = AST_CAUSE_NO_ANSWER;
			} else if (!strcmp(cause, "CANCEL")) {
				q931cause = AST_CAUSE_CALL_REJECTED;
			}
		}
	}

	/* Start the process if it's not already started */
	if (!pvt->alreadygone && !pvt->hangupcause) {
		call_token = pvt->cd.call_token ? strdup(pvt->cd.call_token) : NULL;
		if (call_token) {
			/* Release lock to eliminate deadlock */
			ast_mutex_unlock(&pvt->lock);
			if (h323_clear_call(call_token, q931cause)) { 
				ast_log(LOG_DEBUG, "ClearCall failed.\n");
			}
			free(call_token);
			ast_mutex_lock(&pvt->lock);
		}
	} 
	pvt->needdestroy = 1;

	/* Update usage counter */
	ast_mutex_lock(&usecnt_lock);
	usecnt--;
	if (usecnt < 0) {
		ast_log(LOG_WARNING, "Usecnt < 0\n");
	}
	ast_mutex_unlock(&usecnt_lock);
	ast_mutex_unlock(&pvt->lock);
	ast_update_use_count();
	return 0;
}

static struct ast_frame *oh323_rtp_read(struct oh323_pvt *pvt)
{
	/* Retrieve audio/etc from channel.  Assumes pvt->lock is already held. */
	struct ast_frame *f;

	/* Only apply it for the first packet, we just need the correct ip/port */
	if (pvt->options.nat) {
		ast_rtp_setnat(pvt->rtp, pvt->options.nat);
		pvt->options.nat = 0;
	}

	f = ast_rtp_read(pvt->rtp);
	/* Don't send RFC2833 if we're not supposed to */
	if (f && (f->frametype == AST_FRAME_DTMF) && !(pvt->options.dtmfmode & H323_DTMF_RFC2833)) {
		return &ast_null_frame;
	}
	if (pvt->owner) {
		/* We already hold the channel lock */
		if (f->frametype == AST_FRAME_VOICE) {
			if (f->subclass != pvt->owner->nativeformats) {
				/* Try to avoid deadlock */
				if (ast_mutex_trylock(&pvt->owner->lock)) {
					ast_log(LOG_NOTICE, "Format changed but channel is locked. Ignoring frame...\n");
					return &ast_null_frame;
				}
				ast_log(LOG_DEBUG, "Oooh, format changed to %d\n", f->subclass);
				pvt->owner->nativeformats = f->subclass;
				pvt->nativeformats = f->subclass;
				ast_set_read_format(pvt->owner, pvt->owner->readformat);
				ast_set_write_format(pvt->owner, pvt->owner->writeformat);
				ast_mutex_unlock(&pvt->owner->lock);
			}	
			/* Do in-band DTMF detection */
			if ((pvt->options.dtmfmode & H323_DTMF_INBAND) && pvt->vad) {
				if (!ast_mutex_trylock(&pvt->owner->lock)) {
					f = ast_dsp_process(pvt->owner,pvt->vad,f);
					ast_mutex_unlock(&pvt->owner->lock);
				}
				else
					ast_log(LOG_NOTICE, "Unable to process inband DTMF while channel is locked\n");
				if (f &&(f->frametype == AST_FRAME_DTMF)) {
					ast_log(LOG_DEBUG, "Received in-band digit %c.\n", f->subclass);
				}
			}
		}
	}
	return f;
}

static struct ast_frame *oh323_read(struct ast_channel *c)
{
	struct ast_frame *fr;
	struct oh323_pvt *pvt = (struct oh323_pvt *)c->tech_pvt;
	ast_mutex_lock(&pvt->lock);
	__oh323_update_info(c, pvt);
	fr = oh323_rtp_read(pvt);
	ast_mutex_unlock(&pvt->lock);
	return fr;
}

static int oh323_write(struct ast_channel *c, struct ast_frame *frame)
{
	struct oh323_pvt *pvt = (struct oh323_pvt *) c->tech_pvt;
	int res = 0;
	if (frame->frametype != AST_FRAME_VOICE) {
		if (frame->frametype == AST_FRAME_IMAGE) {
			return 0;
		} else {
			ast_log(LOG_WARNING, "Can't send %d type frames with H323 write\n", frame->frametype);
			return 0;
		}
	} else {
		if (!(frame->subclass & c->nativeformats)) {
			ast_log(LOG_WARNING, "Asked to transmit frame type %d, while native formats is %d (read/write = %d/%d)\n",
				frame->subclass, c->nativeformats, c->readformat, c->writeformat);
			return 0;
		}
	}
	if (pvt) {
		ast_mutex_lock(&pvt->lock);
		if (pvt->rtp) {
			res =  ast_rtp_write(pvt->rtp, frame);
		}
		__oh323_update_info(c, pvt);
		ast_mutex_unlock(&pvt->lock);
	}
	return res;
}

static int oh323_indicate(struct ast_channel *c, int condition)
{

	struct oh323_pvt *pvt = (struct oh323_pvt *) c->tech_pvt;
	char *token = (char *)NULL;

	ast_mutex_lock(&pvt->lock);
	token = (pvt->cd.call_token ? strdup(pvt->cd.call_token) : NULL);
	ast_mutex_unlock(&pvt->lock);

	if (h323debug)
		ast_log(LOG_DEBUG, "OH323: Indicating %d on %s\n", condition, token);

	switch(condition) {
	case AST_CONTROL_RINGING:
		if (c->_state == AST_STATE_RING || c->_state == AST_STATE_RINGING) {
			h323_send_alerting(token);
 			break;
 		}
 		if (token)
 			free(token);
		return -1;
	case AST_CONTROL_PROGRESS:
		if (c->_state != AST_STATE_UP) {
			h323_send_progress(token);
			break;
		}
		if (token)
			free(token);
		return -1;

	case AST_CONTROL_BUSY:
		if (c->_state != AST_STATE_UP) {
			h323_answering_call(token, 1);
			ast_mutex_lock(&pvt->lock);
			pvt->alreadygone = 1;
			ast_mutex_unlock(&pvt->lock);
			ast_softhangup_nolock(c, AST_SOFTHANGUP_DEV);			
			break;
		}
		if (token)
			free(token);
		return -1;
	case AST_CONTROL_CONGESTION:
		if (c->_state != AST_STATE_UP) {
			h323_answering_call(token, 1);
			ast_mutex_lock(&pvt->lock);
			pvt->alreadygone = 1;
			ast_mutex_unlock(&pvt->lock);
			ast_softhangup_nolock(c, AST_SOFTHANGUP_DEV);
			break;
		}
		if (token)
			free(token);
		return -1;
	case AST_CONTROL_PROCEEDING:
	case -1:
		if (token)
			free(token);
		return -1;
	default:
		ast_log(LOG_WARNING, "Don't know how to indicate condition %d on %s\n", condition, token);
		if (token)
			free(token);
		return -1;
	}

	if (h323debug)
		ast_log(LOG_DEBUG, "OH323: Indicated %d on %s\n", condition, token);
	if (token)
		free(token);
	oh323_update_info(c);

	return -1;
}

static int oh323_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
{
	struct oh323_pvt *pvt = (struct oh323_pvt *) newchan->tech_pvt;

	ast_mutex_lock(&pvt->lock);
	if (pvt->owner != oldchan) {
		ast_log(LOG_WARNING, "old channel wasn't %p but was %p\n", oldchan, pvt->owner);
		return -1;
	}
	pvt->owner = newchan;
	ast_mutex_unlock(&pvt->lock);
	return 0;
}

/* Private structure should be locked on a call */
static struct ast_channel *__oh323_new(struct oh323_pvt *pvt, int state, const char *host)
{
	struct ast_channel *ch;
	int fmt;
	
	/* Don't hold a oh323_pvt lock while we allocate a chanel */
	ast_mutex_unlock(&pvt->lock);
	ch = ast_channel_alloc(1);
	/* Update usage counter */
	ast_mutex_lock(&usecnt_lock);
	usecnt++;
	ast_mutex_unlock(&usecnt_lock);
	ast_update_use_count();
	ast_mutex_lock(&pvt->lock);
	if (ch) {
		ch->tech = &oh323_tech;
		ast_string_field_build(ch, name, "H323/%s", host);
		ch->nativeformats = pvt->options.capability;
		if (!ch->nativeformats) {
			ch->nativeformats = global_options.capability;
		}
		pvt->nativeformats = ch->nativeformats;
		fmt = ast_best_codec(ch->nativeformats);
		ch->fds[0] = ast_rtp_fd(pvt->rtp);
		if (state == AST_STATE_RING) {
			ch->rings = 1;
		}
		ch->writeformat = fmt;
		ch->rawwriteformat = fmt;
		ch->readformat = fmt;
		ch->rawreadformat = fmt;
		/* Allocate dsp for in-band DTMF support */
		if (pvt->options.dtmfmode & H323_DTMF_INBAND) {
			pvt->vad = ast_dsp_new();
			ast_dsp_set_features(pvt->vad, DSP_FEATURE_DTMF_DETECT);
        	}
		/* Register channel functions. */
		ch->tech_pvt = pvt;
		/*  Set the owner of this channel */
		pvt->owner = ch;
		
		strncpy(ch->context, pvt->context, sizeof(ch->context) - 1);
		strncpy(ch->exten, pvt->exten, sizeof(ch->exten) - 1);		
		ch->priority = 1;
		if (!ast_strlen_zero(pvt->accountcode)) {
			ast_string_field_set(ch, accountcode, pvt->accountcode);
		}
		if (pvt->amaflags) {
			ch->amaflags = pvt->amaflags;
		}
		if (!ast_strlen_zero(pvt->cid_num)) {
			ch->cid.cid_num = strdup(pvt->cid_num);
		} else if (!ast_strlen_zero(pvt->cd.call_source_e164)) {
			ch->cid.cid_num = strdup(pvt->cd.call_source_e164);
		}
		if (!ast_strlen_zero(pvt->cid_name)) {
			ch->cid.cid_name = strdup(pvt->cid_name);
		} else if (!ast_strlen_zero(pvt->cd.call_source_name)) {
			ch->cid.cid_name = strdup(pvt->cd.call_source_name);
		}
		if (!ast_strlen_zero(pvt->rdnis)) {
			ch->cid.cid_rdnis = strdup(pvt->rdnis);
		}
		if (!ast_strlen_zero(pvt->exten) && strcmp(pvt->exten, "s")) {
			ch->cid.cid_dnid = strdup(pvt->exten);
		}
		ast_setstate(ch, state);
		if (state != AST_STATE_DOWN) {
			if (ast_pbx_start(ch)) {
				ast_log(LOG_WARNING, "Unable to start PBX on %s\n", ch->name);
				ast_hangup(ch);
				ch = NULL;
			}
		}
	} else  {
		ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
	}
	return ch;
}

static struct oh323_pvt *oh323_alloc(int callid)
{
	struct oh323_pvt *pvt;

	pvt = (struct oh323_pvt *) malloc(sizeof(struct oh323_pvt));
	if (!pvt) {
		ast_log(LOG_ERROR, "Couldn't allocate private structure. This is bad\n");
		return NULL;
	}
	memset(pvt, 0, sizeof(struct oh323_pvt));
	pvt->rtp = ast_rtp_new_with_bindaddr(sched, io, 1, 0,bindaddr.sin_addr);
	if (!pvt->rtp) {
		ast_log(LOG_WARNING, "Unable to create RTP session: %s\n", strerror(errno));
		free(pvt);
		return NULL;
	}
	ast_rtp_settos(pvt->rtp, tos);
	ast_mutex_init(&pvt->lock);
	/* Ensure the call token is allocated */
	if ((pvt->cd).call_token == NULL) {
		(pvt->cd).call_token = (char *)malloc(128);
	}
	if (!pvt->cd.call_token) {
		ast_log(LOG_ERROR, "Not enough memory to alocate call token\n");
		return NULL;
	}
	memset((char *)(pvt->cd).call_token, 0, 128);
	pvt->cd.call_reference = callid;
	memcpy(&pvt->options, &global_options, sizeof(pvt->options));
	if (pvt->options.dtmfmode & H323_DTMF_RFC2833) {
		pvt->nonCodecCapability |= AST_RTP_DTMF;
	} else {
		pvt->nonCodecCapability &= ~AST_RTP_DTMF;
	}
	strncpy(pvt->context, default_context, sizeof(pvt->context) - 1);
	pvt->newstate = pvt->newcontrol = -1;
	/* Add to interface list */
	ast_mutex_lock(&iflock);
	pvt->next = iflist;
	iflist = pvt;
	ast_mutex_unlock(&iflock);
	return pvt;
}

static struct oh323_pvt *find_call_locked(int call_reference, const char *token)
{  
	struct oh323_pvt *pvt;

	ast_mutex_lock(&iflock);
	pvt = iflist; 
	while(pvt) {
		if (!pvt->needdestroy && ((signed int)pvt->cd.call_reference == call_reference)) {
			/* Found the call */             
			if ((token != NULL) && (!strcmp(pvt->cd.call_token, token))) {
				ast_mutex_lock(&pvt->lock);
				ast_mutex_unlock(&iflock);
				return pvt;
			} else if (token == NULL) {
				ast_log(LOG_WARNING, "Call Token is NULL\n");
				ast_mutex_lock(&pvt->lock);
				ast_mutex_unlock(&iflock);
				return pvt;
			}
		}
		pvt = pvt->next; 
	}
	ast_mutex_unlock(&iflock);
	return NULL;
}

static int update_state(struct oh323_pvt *pvt, int state, int signal)
{
	if (!pvt)
		return 0;
	if (pvt->owner && !ast_mutex_trylock(&pvt->owner->lock)) {
		if (state >= 0)
			ast_setstate(pvt->owner, state);
		if (signal >= 0)
			ast_queue_control(pvt->owner, signal);
		return 1;
	}
	else {
		if (state >= 0)
			pvt->newstate = state;
		if (signal >= 0)
			pvt->newcontrol = signal;
		return 0;
	}
}

struct oh323_user *find_user(const call_details_t *cd)
{
	struct oh323_user *u;
	char iabuf[INET_ADDRSTRLEN];
	u = userl.users;
	if (userbyalias) {
		while(u) {
			if (!strcasecmp(u->name, cd->call_source_aliases)) {
				break;
			}
			u = u->next;
		}
	} else {
		while(u) {
			if (!strcasecmp(cd->sourceIp, ast_inet_ntoa(iabuf, sizeof(iabuf), u->addr.sin_addr))) {
				break;
			}
			u = u->next;
		}
	}
	return u;
}

struct oh323_peer *find_peer(const char *peer, struct sockaddr_in *sin)
{
	struct oh323_peer *p = NULL;
       	static char iabuf[INET_ADDRSTRLEN];

	p = peerl.peers;
	if (peer) {
		while(p) {
			if (!strcasecmp(p->name, peer)) {
				ast_log(LOG_DEBUG, "Found peer %s by name\n", peer);
				break;
			}
			p = p->next;
		}
	} else {
		/* find by sin */
		if (sin) {
			while (p) {
				if ((!inaddrcmp(&p->addr, sin)) || 
					(p->addr.sin_addr.s_addr == sin->sin_addr.s_addr)) {
					ast_log(LOG_DEBUG, "Found peer %s/%s by addr\n", peer, ast_inet_ntoa(iabuf, sizeof(iabuf), p->addr.sin_addr));
					break;
				}
				p = p->next;
			}
		}	
	}
	if (!p) {
		ast_log(LOG_DEBUG, "Could not find peer %s by name or address\n", peer);
	}
	return p;
}

static int create_addr(struct oh323_pvt *pvt, char *opeer)
{
	struct hostent *hp;
	struct ast_hostent ahp;
	struct oh323_peer *p;
	int portno;
	int found = 0;
	char *port;
	char *hostn;
	char peer[256] = "";

	strncpy(peer, opeer, sizeof(peer) - 1);
	port = strchr(peer, ':');
	if (port) {
		*port = '\0';
		port++;
	}
	pvt->sa.sin_family = AF_INET;
	ast_mutex_lock(&peerl.lock);
	p = find_peer(peer, NULL);
	if (p) {
		found++;
		memcpy(&pvt->options, &p->options, sizeof(pvt->options));
		if (pvt->rtp) {
			ast_log(LOG_DEBUG, "Setting NAT on RTP to %d\n", pvt->options.nat);
			ast_rtp_setnat(pvt->rtp, pvt->options.nat);
		}
		if (pvt->options.dtmfmode) {
			if (pvt->options.dtmfmode & H323_DTMF_RFC2833) {
				pvt->nonCodecCapability |= AST_RTP_DTMF;
			} else {
				pvt->nonCodecCapability &= ~AST_RTP_DTMF;
			}
		}
		if (p->addr.sin_addr.s_addr) {
			pvt->sa.sin_addr = p->addr.sin_addr;	
			pvt->sa.sin_port = p->addr.sin_port;	
		} 
	}
	ast_mutex_unlock(&peerl.lock);
	if (!p && !found) {
		hostn = peer;
		if (port) {
			portno = atoi(port);
		} else {
			portno = h323_signalling_port;
		}		
		hp = ast_gethostbyname(hostn, &ahp);
		if (hp) {
			memcpy(&pvt->options, &global_options, sizeof(pvt->options));
			memcpy(&pvt->sa.sin_addr, hp->h_addr, sizeof(pvt->sa.sin_addr));