chan_h323.c

/*
 * chan_h323.c
 *
 * 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
 *
 * This file is part of the chan_h323 driver for Asterisk
 *
 * chan_h323 is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version. 
 *
 * chan_h323 is distributed WITHOUT ANY WARRANTY; without even 
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
 * PURPOSE. See the GNU General Public License for more details. 
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
 *
 * Version Info: $Id$
 */

#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/lock.h>
#include <asterisk/logger.h>
#include <asterisk/channel.h>
#include <asterisk/channel_pvt.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>
#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;

/* global debug flag */
int h323debug;

/** Variables required by Asterisk */
static char *type = "H323";
static char *desc = "The NuFone Network's Open H.323 Channel Driver";
static char *tdesc = "The NuFone Network's Open H.323 Channel Driver";
static char *config = "h323.conf";
static char default_context[AST_MAX_EXTENSION] = "default";

/** 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;
static int noFastStart = 0;
static int noH245Tunneling = 0;
static int noSilenceSuppression = 0;
/* Assume we can native bridge by default */
static int bridging = 1;
/* Find user by alias (h.323 id) is default, alternative is the incomming call's source IP address*/
static int  userbyalias = 1;
/* Just about everybody seems to support ulaw, so make it a nice default */
static int capability = AST_FORMAT_ULAW;
/* TOS flag */
static int tos = 0;
static int dtmfmode = H323_DTMF_RFC2833;
static char secret[50];

/** 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 capability;						/* audio capability */
	int nonCodecCapability;					/* non-audio capability */
	int outgoing;						/* Outgoing or incoming call? */
	int nat;						/* Are we talking to a NAT EP?*/
	int bridge;						/* Determine of we should native bridge or not*/
	char exten[AST_MAX_EXTENSION];				/* Requested extension */
	char context[AST_MAX_EXTENSION];			/* Context where to start */
	char username[81];					/* H.323 alias using this channel */
	char accountcode[256];					/* Account code */
	int amaflags;						/* AMA Flags */
	char callerid[80];					/* Caller*ID if available */
	struct ast_rtp *rtp;					/* RTP Session */
	int dtmfmode;						/* What DTMF Mode is being used */
	struct ast_dsp *vad;					/* Used for in-band DTMF detection */
	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 void __oh323_destroy(struct oh323_pvt *p)
{
	struct oh323_pvt *cur, *prev = NULL;
	
	if (p->rtp) {
		ast_rtp_destroy(p->rtp);
	}
	
	/* Unlink us from the owner if we have one */
	if (p->owner) {
		ast_mutex_lock(&p->owner->lock);
		ast_log(LOG_DEBUG, "Detaching from %s\n", p->owner->name);
		p->owner->pvt->pvt = NULL;
		ast_mutex_unlock(&p->owner->lock);
	}
	cur = iflist;
	while(cur) {
		if (cur == p) {
			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(&p->lock);
		free(p);
        }
}

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

static struct oh323_alias *build_alias(char *name, struct ast_variable *v)
{
	struct oh323_alias *alias;

	alias = (struct oh323_alias *)malloc(sizeof(struct oh323_alias));

	if (alias) {
		memset(alias, 0, sizeof(struct oh323_alias));
		strncpy(alias->name, name, sizeof(alias->name) - 1);
		while (v) {
			if (!strcasecmp(v->name, "e164")) {
				strncpy(alias->e164,  v->value, sizeof(alias->e164) - 1);
			} else if (!strcasecmp(v->name, "prefix")) {
				strncpy(alias->prefix,  v->value, sizeof(alias->prefix) - 1);
			} else if (!strcasecmp(v->name, "context")) {
				strncpy(alias->context,  v->value, sizeof(alias->context) - 1);
			} else if (!strcasecmp(v->name, "secret")) {
				strncpy(alias->secret,  v->value, sizeof(alias->secret) - 1);
			} else {
				if (strcasecmp(v->value, "h323")) { 	
					ast_log(LOG_WARNING, "Keyword %s does not make sense in type=h323\n", v->value);
				}
			}
			v = v->next;
		}
	}
	return alias;
}

static struct oh323_user *build_user(char *name, struct ast_variable *v)
{
	struct oh323_user *user;
	int format;
	
	user = (struct oh323_user *)malloc(sizeof(struct oh323_user));
	if (user) {
		memset(user, 0, sizeof(struct oh323_user));
		strncpy(user->name, name, sizeof(user->name) - 1);
		
		/* set the usage flag to a sane starting value*/
		user->inUse = 0;
		/* set the native brigding default */
		user->bridge = bridging;
		strncpy(user->context, default_context, sizeof(user->context) - 1);

		while(v) {
			if (!strcasecmp(v->name, "context")) {
				strncpy(user->context, v->value, sizeof(user->context) - 1);
			} else if (!strcasecmp(v->name, "bridge")) {
				user->bridge = ast_true(v->value);
                      } else if (!strcasecmp(v->name, "nat")) {
                              user->nat = ast_true(v->value);
			} else if (!strcasecmp(v->name, "noFastStart")) {
				user->noFastStart = ast_true(v->value);
			} else if (!strcasecmp(v->name, "noH245Tunneling")) {
				user->noH245Tunneling = ast_true(v->value);
			} else if (!strcasecmp(v->name, "noSilenceSuppression")) {
				user->noSilenceSuppression = ast_true(v->value);
			} else if (!strcasecmp(v->name, "secret")) {
				strncpy(user->secret, v->value, sizeof(user->secret) - 1);
			} else if (!strcasecmp(v->name, "callerid")) {
				strncpy(user->callerid, v->value, sizeof(user->callerid) - 1);
			} else if (!strcasecmp(v->name, "accountcode")) {
				strncpy(user->accountcode, v->value, sizeof(user->accountcode) - 1);
			} else if (!strcasecmp(v->name, "incominglimit")) {
				user->incominglimit = atoi(v->value);
				if (user->incominglimit < 0)
					user->incominglimit = 0;
			} else if (!strcasecmp(v->name, "host")) {
				if (!strcasecmp(v->value, "dynamic")) {
					ast_log(LOG_ERROR, "A dynamic host on a type=user does not make any sense\n");
					free(user);
					return NULL;
				} else if (ast_get_ip(&user->addr, v->value)) {
					free(user);
					return NULL;
				} 
				/* Let us know we need to use ip authentication */
				user->host = 1;
			} else if (!strcasecmp(v->name, "amaflags")) {
				format = ast_cdr_amaflags2int(v->value);
				if (format < 0) {
					ast_log(LOG_WARNING, "Invalid AMA Flags: %s at line %d\n", v->value, v->lineno);
				} else {
					user->amaflags = format;
				}
			}
			v = v->next;
		}
	}
	return user;
}

static struct oh323_peer *build_peer(char *name, struct ast_variable *v)
{
	struct oh323_peer *peer;
	struct oh323_peer *prev;
	struct ast_ha *oldha = NULL;
	int found=0;
	int format;	

	prev = NULL;
	ast_mutex_lock(&peerl.lock);
	peer = peerl.peers;

	while(peer) {
		if (!strcasecmp(peer->name, name)) {	
			break;
		}
		prev = peer;
		peer = peer->next;
	}

	if (peer) {
		found++;
		/* Already in the list, remove it and it will be added back (or FREE'd) */
		if (prev) {
			prev->next = peer->next;
		} else {
			peerl.peers = peer->next;
		}
		ast_mutex_unlock(&peerl.lock);
 	} else {
		ast_mutex_unlock(&peerl.lock);
		peer = (struct oh323_peer*)malloc(sizeof(struct oh323_peer));
		memset(peer, 0, sizeof(struct oh323_peer));
	}
	if (peer) {
		if (!found) {
			strncpy(peer->name, name, sizeof(peer->name) - 1);
			peer->addr.sin_port = htons(h323_signalling_port);
			peer->addr.sin_family = AF_INET;
		}
		oldha = peer->ha;
		peer->ha = NULL;
		peer->addr.sin_family = AF_INET;
		peer->capability = capability;

		while(v) {
			if (!strcasecmp(v->name, "bridge")) {
				peer->bridge = ast_true(v->value);
			} else if (!strcasecmp(v->name, "nat")) {
				peer->nat = ast_true(v->value);
			} else if (!strcasecmp(v->name, "noFastStart")) {
				peer->noFastStart = ast_true(v->value);
			} else if (!strcasecmp(v->name, "noH245Tunneling")) {
				peer->noH245Tunneling = ast_true(v->value);
			} else if (!strcasecmp(v->name, "noSilenceSuppression")) {
				peer->noSilenceSuppression = ast_true(v->value);
			} else if (!strcasecmp(v->name, "dtmfmode")) {
				if (!strcasecmp(v->value, "inband")) {
					peer->dtmfmode = H323_DTMF_INBAND;
				} else if (!strcasecmp(v->value, "rfc2833")) {
					peer->dtmfmode = H323_DTMF_RFC2833;
				} else {
					ast_log(LOG_WARNING, "Unknown DTMF Mode %s, using RFC2833\n", v->value);
					peer->dtmfmode = H323_DTMF_RFC2833;
				}	
			} else if (!strcasecmp(v->name, "allow")) {
				format = ast_getformatbyname(v->value);
				if (format < 1) {
					ast_log(LOG_WARNING, "Cannot allow unknown format '%s'\n", v->value);
				} else {
					peer->capability |= format;
				}
			} else if (!strcasecmp(v->name, "disallow")) {
				format = ast_getformatbyname(v->value);
				if (format < 1) {
					ast_log(LOG_WARNING, "Cannot disallow unknown format '%s'\n", v->value);
				} else {
					peer->capability |= ~format;
				}
			} else if (!strcasecmp(v->name, "outgoinglimit")) {
				peer->outgoinglimit = atoi(v->value);
				if (peer->outgoinglimit > 0) {
					peer->outgoinglimit = 0;
				}
			} else if (!strcasecmp(v->name, "host")) {
				if (!strcasecmp(v->value, "dynamic")) {
					ast_log(LOG_ERROR, "Dynamic host configuration not implemented.\n");
					free(peer);
					return NULL;
				}
				if (ast_get_ip(&peer->addr, v->value)) {
						ast_log(LOG_ERROR, "Could not determine IP for %s\n", v->value);
						free(peer);
						return NULL;
				}
			} else if (!strcasecmp(v->name, "port")) {
				peer->addr.sin_port = htons(atoi(v->value));
			}
			v=v->next;
		}
	}
	return peer;
}

/**
 * Send (play) the specified digit to the channel.
 * 
 */
static int oh323_digit(struct ast_channel *c, char digit)
{
	struct oh323_pvt *p = (struct oh323_pvt *) c->pvt->pvt;
	if (p && p->rtp && (p->dtmfmode & H323_DTMF_RFC2833)) {
		ast_rtp_senddigit(p->rtp, digit);
	}
	/* If in-band DTMF is desired, send that */
	if (p->dtmfmode & H323_DTMF_INBAND)
		h323_send_tone(p->cd.call_token, digit);
	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->pvt->pvt;
	char called_addr[INET_ADDRSTRLEN];

	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;
	}
	/* Clear and then set the address to call */
	memset(called_addr, 0, sizeof(called_addr));
	if (usingGk) {
		memcpy(called_addr, dest, strlen(called_addr));
		pvt->options.noFastStart = noFastStart;
		pvt->options.noH245Tunneling = noH245Tunneling;
		pvt->options.noSilenceSuppression = noSilenceSuppression;
		pvt->options.port = h323_signalling_port;
	} else {
		ast_inet_ntoa(called_addr, sizeof(called_addr), pvt->sa.sin_addr);
		pvt->options.port = htons(pvt->sa.sin_port);
	}
	/* indicate that this is an outgoing call */
	pvt->outgoing = 1;
	ast_log(LOG_DEBUG, "Outgoing call to %s:%d\n", called_addr, pvt->options.port);
	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;
	}
	return 0;
}

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

	res = h323_answering_call(pvt->cd.call_token, 0);
	
	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->pvt->pvt;
	int needcancel = 0;
	if (h323debug)
		ast_log(LOG_DEBUG, "oh323_hangup(%s)\n", c->name);
	if (!c->pvt->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;
	/* Disconnect */
	pvt = (struct oh323_pvt *) c->pvt->pvt;
	
	/* Free dsp used for in-band DTMF detection */
	if (pvt->vad) {
		ast_dsp_free(pvt->vad);
	}

	pvt->owner = NULL;
	c->pvt->pvt = NULL;

	/* Start the process if it's not already started */
	if (!pvt->alreadygone) {
		if (h323_clear_call((pvt->cd).call_token)) { 
			ast_log(LOG_DEBUG, "ClearCall failed.\n");
		}
		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_update_use_count();

	ast_mutex_unlock(&pvt->lock);
	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;
	static struct ast_frame null_frame = { AST_FRAME_NULL, };

      /* Only apply it for the first packet, we just need the correct ip/port */
      if(pvt->nat)
      {
              ast_rtp_setnat(pvt->rtp,pvt->nat);
              pvt->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->dtmfmode & H323_DTMF_RFC2833))
		return &null_frame;
	if (pvt->owner) {
		/* We already hold the channel lock */
		if (f->frametype == AST_FRAME_VOICE) {
			if (f->subclass != pvt->owner->nativeformats) {
				ast_log(LOG_DEBUG, "Oooh, format changed to %d\n", f->subclass);
				pvt->owner->nativeformats = f->subclass;
				ast_set_read_format(pvt->owner, pvt->owner->readformat);
				ast_set_write_format(pvt->owner, pvt->owner->writeformat);
			}
		
			/* Do in-band DTMF detection */
			if (pvt->dtmfmode & H323_DTMF_INBAND) {
                   		f = ast_dsp_process(pvt->owner,pvt->vad,f);
				if (f->frametype == AST_FRAME_DTMF) {
					ast_log(LOG_DEBUG, "Got 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->pvt->pvt;
	ast_mutex_lock(&pvt->lock);
	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->pvt->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 -1;
		}
	}
	if (pvt) {
		ast_mutex_lock(&pvt->lock);
		if (pvt->rtp) {
			res =  ast_rtp_write(pvt->rtp, frame);
		}
		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->pvt->pvt;
	
	switch(condition) {
	case AST_CONTROL_RINGING:
		if (c->_state == AST_STATE_RING || c->_state == AST_STATE_RINGING) {
			h323_send_alerting(pvt->cd.call_token);
 			break;
 		}		
		return -1;
	case AST_CONTROL_PROGRESS:
		if (c->_state != AST_STATE_UP) {
			h323_send_progress(pvt->cd.call_token);
			break;
		}
		return -1;

	case AST_CONTROL_BUSY:
		if (c->_state != AST_STATE_UP) {
			h323_answering_call(pvt->cd.call_token, 1);
 			pvt->alreadygone = 1;
			ast_softhangup_nolock(c, AST_SOFTHANGUP_DEV);			
			break;
		}
		return -1;
	case AST_CONTROL_CONGESTION:
		if (c->_state != AST_STATE_UP) {
			h323_answering_call(pvt->cd.call_token, 1);
			pvt->alreadygone = 1;
			ast_softhangup_nolock(c, AST_SOFTHANGUP_DEV);
			break;
		}
		return -1;
	case AST_CONTROL_PROCEEDING:
	case -1:
		return -1;
	default:
		ast_log(LOG_WARNING, "Don't know how to indicate condition %d\n", condition);
		return -1;
	}
	return 0;
}

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

static struct ast_channel *oh323_new(struct oh323_pvt *pvt, int state, const char *host)
{
	struct ast_channel *ch;
	int fmt;
	ch = ast_channel_alloc(1);
	
	if (ch) {
		
		snprintf(ch->name, sizeof(ch->name), "H323/%s", host);
		ch->nativeformats = pvt->capability;
		if (!ch->nativeformats)
			ch->nativeformats = capability;
		fmt = ast_best_codec(ch->nativeformats);
		ch->type = type;
		ch->fds[0] = ast_rtp_fd(pvt->rtp);
		
		if (state == AST_STATE_RING)
			ch->rings = 1;
		
		ch->writeformat = fmt;
		ch->pvt->rawwriteformat = fmt;
		ch->readformat = fmt;
		ch->pvt->rawreadformat = fmt;
		
		/* Allocate dsp for in-band DTMF support */
		if (pvt->dtmfmode & H323_DTMF_INBAND) {
			pvt->vad = ast_dsp_new();
			ast_dsp_set_features(pvt->vad, DSP_FEATURE_DTMF_DETECT);
        	}

		/* Register the OpenH323 channel's functions. */
		ch->pvt->pvt = pvt;
		ch->pvt->send_digit = oh323_digit;
		ch->pvt->call = oh323_call;
		ch->pvt->hangup = oh323_hangup;
		ch->pvt->answer = oh323_answer;
		ch->pvt->read = oh323_read;
		ch->pvt->write = oh323_write;
		ch->pvt->indicate = oh323_indicate;
		ch->pvt->fixup = oh323_fixup;
	     /*	ch->pvt->bridge = ast_rtp_bridge; */

		/*  Set the owner of this channel */
		pvt->owner = ch;
		
		ast_mutex_lock(&usecnt_lock);
		usecnt++;
		ast_mutex_unlock(&usecnt_lock);
		ast_update_use_count();
		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))
			strncpy(ch->accountcode, pvt->accountcode, sizeof(ch->accountcode) - 1);
		if (pvt->amaflags)
			ch->amaflags = pvt->amaflags;
		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;
	}
	/* Keep track of stuff */
	memset(pvt, 0, sizeof(struct oh323_pvt));
	pvt->rtp = ast_rtp_new(sched, io, 1, 0);
	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);
	}
	memset((char *)(pvt->cd).call_token, 0, 128);
	if (!pvt->cd.call_token) {
		ast_log(LOG_ERROR, "Not enough memory to alocate call token\n");
		return NULL;
	}
	pvt->cd.call_reference = callid;
	pvt->bridge = bridging;	
	pvt->dtmfmode = dtmfmode;
	if (pvt->dtmfmode & H323_DTMF_RFC2833) {
		pvt->nonCodecCapability |= AST_RTP_DTMF;
	}
	strncpy(pvt->context, default_context, sizeof(pvt->context) - 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(int call_reference, const char *token)
{  
        struct oh323_pvt *pvt;

	ast_mutex_lock(&iflock);
        pvt = iflist; 
        while(pvt) {
                if ((signed int)pvt->cd.call_reference == call_reference) {
                        /* Found the call */             
                        if ((token != NULL) && (strcmp(pvt->cd.call_token, token) == 0)) {
        			ast_mutex_unlock(&iflock);
	        		return pvt;
                        } else if(token == NULL) {
                                ast_log(LOG_DEBUG, "token is NULL, skipping comparition\n");
                                ast_mutex_unlock(&iflock);
                                return pvt;
                        }
                }
                pvt = pvt->next; 
        }
        ast_mutex_unlock(&iflock);
	return NULL;
}

struct oh323_user *find_user(const call_details_t cd)
{
	struct oh323_user *u;
	char iabuf[INET_ADDRSTRLEN];
	u = userl.users;
	if(userbyalias == 1){
		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(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++;
		pvt->capability = p->capability;
		pvt->nat = p->nat;
		if (pvt->rtp) {
			ast_log(LOG_DEBUG, "Setting NAT on RTP to %d\n", pvt->nat);
			ast_rtp_setnat(pvt->rtp, pvt->nat);
		}
		pvt->options.noFastStart = p->noFastStart;
		pvt->options.noH245Tunneling = p->noH245Tunneling;
		pvt->options.noSilenceSuppression = p->noSilenceSuppression;
		if (pvt->dtmfmode) {
			pvt->dtmfmode = p->dtmfmode;
			if (pvt->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->sa.sin_addr, hp->h_addr, sizeof(pvt->sa.sin_addr));
			pvt->sa.sin_port = htons(portno);
			return 0;	
		} else {
			ast_log(LOG_WARNING, "No such host: %s\n", peer);
			return -1;
		}
	} else if (!p) {
		return -1;
	} else {	
		return 0;
	}
}
static struct ast_channel *oh323_request(const char *type, int format, void *data)
{
	int oldformat;
	struct oh323_pvt *pvt;
	struct ast_channel *tmpc = NULL;
	char *dest = (char *)data;
	char *ext, *host;
	char *h323id = NULL;
	char tmp[256];
	
	ast_log(LOG_DEBUG, "type=%s, format=%d, data=%s.\n", type, format, (char *)data);

	pvt = oh323_alloc(0);
	if (!pvt) {
		ast_log(LOG_WARNING, "Unable to build pvt data for '%s'\n", (char *)data);
		return NULL;
	}	

	oldformat = format;
	format &= ((AST_FORMAT_MAX_AUDIO << 1) - 1);
	if (!format) {
		ast_log(LOG_NOTICE, "Asked to get a channel of unsupported format '%d'\n", format);
		return NULL;
	}
	/* Assign default capabilities */
	pvt->capability = capability;
	pvt->dtmfmode = H323_DTMF_RFC2833;

	strncpy(tmp, dest, sizeof(tmp) - 1);	
	host = strchr(tmp, '@');
	if (host) {
		*host = '\0';
		host++;
		ext = tmp;
	} else {
		host = tmp;
		ext = NULL;
	}
	strtok_r(host, "/", &(h323id));		
	if (h323id && !ast_strlen_zero(h323id)) {
		h323_set_id(h323id);
	}
	if (ext) {
		strncpy(pvt->username, ext, sizeof(pvt->username) - 1);
	}
	ast_log(LOG_DEBUG, "Host: %s\tUsername: %s\n", host, pvt->username);

	if (!usingGk) {
		if (create_addr(pvt, host)) {
			oh323_destroy(pvt);
			return NULL;
		}
	}
	/* pass on our capabilites to the H.323 stack */
	ast_mutex_lock(&caplock);
	h323_set_capability(pvt->capability, pvt->dtmfmode);
	ast_mutex_unlock(&caplock);