path: root/tinySIP/src/dialogs/tsip_dialog_layer.c

/*
* Copyright (C) 2010-2011 Mamadou Diop.
*
* Contact: Mamadou Diop <diopmamadou(at)doubango[dot]org>
*	
* This file is part of Open Source Doubango Framework.
*
* DOUBANGO 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 3 of the License, or
* (at your option) any later version.
*	
* DOUBANGO is distributed in the hope that it will be useful,
* but 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 DOUBANGO.
*
*/

/**@file tsip_dialog_layer.c
 * @brief SIP dialog layer.
 *
 * @author Mamadou Diop <diopmamadou(at)doubango[dot]org>
 *

 */
#include "tinysip/dialogs/tsip_dialog_layer.h"

#include "tinysip/dialogs/tsip_dialog_invite.h"
#include "tinysip/dialogs/tsip_dialog_message.h"
#include "tinysip/dialogs/tsip_dialog_info.h"
#include "tinysip/dialogs/tsip_dialog_options.h"
#include "tinysip/dialogs/tsip_dialog_publish.h"
#include "tinysip/dialogs/tsip_dialog_register.h"
#include "tinysip/dialogs/tsip_dialog_subscribe.h"

#include "tinysip/transactions/tsip_transac_layer.h"
#include "tinysip/transports/tsip_transport_layer.h"

#include "tsk_debug.h"

extern tsip_ssession_handle_t *tsip_ssession_create_2(const tsip_stack_t* stack, const struct tsip_message_s* message);

/*== Predicate function to find dialog by type */
static int pred_find_dialog_by_type(const tsk_list_item_t *item, const void *type)
{
	if(item && item->data){
		tsip_dialog_t *dialog = item->data;
		return (dialog->type - *((tsip_dialog_type_t*)type));
	}
	return -1;
}

/*== Predicate function to find dialog by not type */
static int pred_find_dialog_by_not_type(const tsk_list_item_t *item, const void *type)
{
	if(item && item->data){
		tsip_dialog_t *dialog = item->data;
		if(dialog->type != *((tsip_dialog_type_t*)type)){
			return 0;
		}
	}
	return -1;
}

/*== Predicate function to find dialog by callid */
static int pred_find_dialog_by_callid(const tsk_list_item_t *item, const void *callid)
{
	if(item && item->data && callid){
		return tsk_strcmp(((tsip_dialog_t*)item->data)->callid, ((const char*)callid));
	}
	return -1;
}

tsip_dialog_layer_t* tsip_dialog_layer_create(tsip_stack_t* stack)
{
	return tsk_object_new(tsip_dialog_layer_def_t, stack);
}

// it's up to the caller to release the returned object
tsip_dialog_t* tsip_dialog_layer_find_by_ss(tsip_dialog_layer_t *self, const tsip_ssession_handle_t *ss)
{
	return tsip_dialog_layer_find_by_ssid(self, tsip_ssession_get_id(ss));
}

// it's up to the caller to release the returned object
tsip_dialog_t* tsip_dialog_layer_find_by_ssid(tsip_dialog_layer_t *self, tsip_ssession_id_t ssid)
{
	tsip_dialog_t *ret = 0;
	tsip_dialog_t *dialog;
	tsk_list_item_t *item;

	tsk_safeobj_lock(self);

	tsk_list_foreach(item, self->dialogs){
		dialog = item->data;
		if(tsip_ssession_get_id(dialog->ss) == ssid){
			ret = dialog;
			break;
		}
	}

	tsk_safeobj_unlock(self);

	return tsk_object_ref(ret);
}

// it's up to the caller to release the returned object
tsip_dialog_t* tsip_dialog_layer_find_by_callid(tsip_dialog_layer_t *self, const char* callid)
{
	if(!self || !callid){
		TSK_DEBUG_ERROR("Invalid parameter");
		return tsk_null;
	}
	else{
		tsip_dialog_t *dialog = tsk_null;
		tsk_list_item_t *item;
		//--tsk_safeobj_lock(self);
		tsk_list_foreach(item, self->dialogs){
			if(tsk_striequals(TSIP_DIALOG(item->data)->callid, callid)){
				dialog = tsk_object_ref(item->data);
				break;
			}
		}
		//--tsk_safeobj_unlock(self);
		return dialog;
	}
}

tsk_bool_t tsip_dialog_layer_have_dialog_with_callid(const tsip_dialog_layer_t *self, const char* callid)
{
	tsk_bool_t found = tsk_false;
	if(self){
		tsk_safeobj_lock(self);
		if(tsk_list_find_item_by_pred(self->dialogs, pred_find_dialog_by_callid, callid) != tsk_null){
			found = tsk_true;
		}
		tsk_safeobj_unlock(self);
	}
	return found;
}

// it's up to the caller to release the returned object
tsip_dialog_t* tsip_dialog_layer_find(const tsip_dialog_layer_t *self, const char* callid, const char* to_tag, const char* from_tag, tsip_request_type_t type, tsk_bool_t *cid_matched)
{
	tsip_dialog_t *ret = tsk_null;
	tsip_dialog_t *dialog;
	tsk_list_item_t *item;

	*cid_matched = tsk_false;
	
	tsk_safeobj_lock(self);

	tsk_list_foreach(item, self->dialogs){
		dialog = item->data;
		if(tsk_strequals(dialog->callid, callid)){
			tsk_bool_t is_cancel = (type == tsip_CANCEL); // Incoming CANCEL
			tsk_bool_t is_register = (type == tsip_REGISTER); // Incoming REGISTER
			tsk_bool_t is_notify = (type == tsip_NOTIFY); // Incoming NOTIFY
			*cid_matched = tsk_true;
			/* CANCEL Request will have the same local tag than the INVITE request
				the remote tag could be null if the CANCEL request is received immediately after a 100 Trying
			*/
			if((is_cancel || tsk_strequals(dialog->tag_local, from_tag)) && (!dialog->tag_remote || tsk_strequals(dialog->tag_remote, to_tag))){
				ret = tsk_object_ref(dialog);
				break;
			}
			/* REGISTER is dialogless which means that each reREGISTER or unREGISTER will have empty to tag  */
			if(is_register /* Do not check tags */){
				ret = tsk_object_ref(dialog);
				break;
			}
			/*	NOTIFY could arrive before the 200 SUBSCRIBE => This is why we don't try to match both tags
			 
				RFC 3265 - 3.1.4.4. Confirmation of Subscription Creation
				Due to the potential for both out-of-order messages and forking, the
				subscriber MUST be prepared to receive NOTIFY messages before the
				SUBSCRIBE transaction has completed.
			 */
			if(is_notify /* Do not check tags */){
				ret = tsk_object_ref(dialog);
				break;
			}
		}
	}

	tsk_safeobj_unlock(self);

	return ret;
}

tsk_size_t tsip_dialog_layer_count_active_calls(tsip_dialog_layer_t *self)
{
	tsk_size_t count = 0;

	tsip_dialog_t *dialog;
	tsk_list_item_t *item;

	tsk_safeobj_lock(self);

	tsk_list_foreach(item, self->dialogs) {
		if ((dialog = item->data) && dialog->type == tsip_dialog_INVITE && dialog->state != tsip_initial && dialog->state != tsip_terminated) {
			++count;
		}
	}

	tsk_safeobj_unlock(self);

	return count;
}

/** Hangup all dialogs starting by non-REGISTER  */
int tsip_dialog_layer_shutdownAll(tsip_dialog_layer_t *self)
{
	if(self){
		tsk_bool_t wait = tsk_false;
		tsk_list_item_t *item;
		tsip_dialog_t *dialog;
		tsip_dialog_type_t regtype = tsip_dialog_REGISTER;

		if(!self->shutdown.inprogress){
			self->shutdown.inprogress = tsk_true;
			if (!self->shutdown.condwait) {
				self->shutdown.condwait = tsk_condwait_create();
			}
		}
		
		tsk_safeobj_lock(self);
		if(tsk_list_count(self->dialogs, pred_find_dialog_by_not_type, &regtype)){
			/* There are non-register dialogs ==> phase-1 */
			goto phase1;
		}
		else if(tsk_list_count(self->dialogs, pred_find_dialog_by_type, &regtype)){
			/* There are one or more register dialogs ==> phase-2 */
			goto phase2;
		}
		else{
			tsk_safeobj_unlock(self);
			goto done;
		}

phase1:
		/* Phase 1 - shutdown all except register and silent_hangup */
		TSK_DEBUG_INFO("== Shutting down - Phase-1 started ==");
phase1_loop:
		tsk_list_foreach(item, self->dialogs){
			dialog = item->data;
			if(dialog->type != tsip_dialog_REGISTER && !dialog->ss->silent_hangup){
				item = tsk_object_ref(item);
				if(!tsip_dialog_shutdown(dialog, tsk_null)){
					wait = tsk_true;
				}

				// if "tsip_dialog_shutdown()" remove the dialog, then
				// "self->dialogs" will be unsafe
				if(!(item = tsk_object_unref(item))){
					goto phase1_loop;
				}
			}
		}
		tsk_safeobj_unlock(self);
		
		/* wait until phase-1 is completed */
		if(wait){
			tsk_condwait_timedwait(self->shutdown.condwait, TSIP_DIALOG_SHUTDOWN_TIMEOUT);
		}
		
		/* lock and goto phase2 */
		tsk_safeobj_lock(self);
		wait = tsk_false;
		goto phase2;

phase2:
		/* Phase 2 - unregister */
		TSK_DEBUG_INFO("== Shutting down - Phase-2 started ==");
		self->shutdown.phase2 = tsk_true;
phase2_loop:
		tsk_list_foreach(item, self->dialogs){
			dialog = item->data;
			if(dialog->type == tsip_dialog_REGISTER){
				item = tsk_object_ref(item);
				if(!tsip_dialog_shutdown(dialog, tsk_null)){
					wait = tsk_true;
				}
				// if "tsip_dialog_shutdown()" remove the dialog, then
				// "self->dialogs" will be unsafe 
				if(!(item = tsk_object_unref(item))){
					goto phase2_loop;
				}
			}
		}
		tsk_safeobj_unlock(self);

		/* wait until phase-2 is completed */
		if(wait){
			tsk_condwait_timedwait(self->shutdown.condwait, TSIP_DIALOG_SHUTDOWN_TIMEOUT);
		}


		/* Phase 3 - silenthangup (dialogs will be terminated immediately) */
		TSK_DEBUG_INFO("== Shutting down - Phase-3 ==");
phase3_loop:
		tsk_list_foreach(item, self->dialogs){
			dialog = item->data;
			if(dialog->ss->silent_hangup){
				item = tsk_object_ref(item);
				tsip_dialog_shutdown(dialog, tsk_null);

				// if "tsip_dialog_shutdown()" remove the dialog, then
				// "self->dialogs" will became unsafe while looping
				if(!(item = tsk_object_unref(item))){
					goto phase3_loop;
				}
			}
		}

done:
		TSK_DEBUG_INFO("== Shutting down - Terminated ==");
		return 0;
	}
	return -1;
}

static void* TSK_STDCALL _tsip_dialog_signal_transport_error_async(void* dialog)
{
    tsip_dialog_signal_transport_error(TSIP_DIALOG(dialog));
    return tsk_null;
}

int tsip_dialog_layer_signal_stack_disconnected(tsip_dialog_layer_t *self)
{
	tsk_list_item_t *item;
    // use copy  for lock-free code and faster code. also fix issue 172 (https://code.google.com/p/idoubs/issues/detail?id=172)
    tsip_dialogs_L_t *dialogs_copy;
    tsip_dialog_t *dialog;
	if(!self){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}
    
    if (!(dialogs_copy = tsk_list_create())) {
        TSK_DEBUG_ERROR("Failed to create list");
		return -1;
    }

	tsk_safeobj_lock(self);
    tsk_list_pushback_list(dialogs_copy, self->dialogs);
    tsk_safeobj_unlock(self);
    
    tsk_list_foreach(item, dialogs_copy){
        if((dialog = TSIP_DIALOG(item->data))){
            tsip_dialog_signal_transport_error(dialog);
        }
    }
    TSK_OBJECT_SAFE_FREE(dialogs_copy);
	return 0;
}

int tsip_dialog_layer_signal_peer_disconnected(tsip_dialog_layer_t *self, const struct tsip_transport_stream_peer_s* peer)
{
	tsip_dialog_t *dialog;
	const tsk_list_item_t *item;

	if(!self || !peer){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}
    
    //!\ must not lock the entire layer

	// tsk_safeobj_lock(self);

	tsk_list_lock(peer->dialogs_cids);
	tsk_list_foreach(item, peer->dialogs_cids){
		if((dialog = tsip_dialog_layer_find_by_callid(self, TSK_STRING_STR(item->data)))){
			tsip_dialog_signal_transport_error(dialog);
			TSK_OBJECT_SAFE_FREE(dialog);
		}
		else{
			// To avoid this WARN, you should call tsip_dialog_layer_have_dialog_with_callid() before adding a callid to a peer
			TSK_DEBUG_WARN("Stream peer holds call-id='%s' but the dialog layer doesn't know it", TSK_STRING_STR(item->data));
		}
	}
	tsk_list_unlock(peer->dialogs_cids);

	// tsk_safeobj_unlock(self);

	return 0;
}

int tsip_dialog_layer_remove_callid_from_stream_peers(tsip_dialog_layer_t *self, const char* callid)
{
	if(self){
		return tsip_transport_layer_remove_callid_from_stream_peers(self->stack->layer_transport, callid);
	}
	TSK_DEBUG_ERROR("Invalid parameter");
	return -1;
}

/* the caller of this function must unref() the returned object */
tsip_dialog_t* tsip_dialog_layer_new(tsip_dialog_layer_t *self, tsip_dialog_type_t type, const tsip_ssession_t *ss)
{
	tsip_dialog_t* ret = tsk_null;
	tsip_dialog_t* dialog;
	if(!self){
		TSK_DEBUG_ERROR("Invalid parameter");
		goto bail;
	}

	switch(type){
		case tsip_dialog_INVITE:
			{
				if((dialog = (tsip_dialog_t*)tsip_dialog_invite_create(ss, tsk_null))){
					ret = tsk_object_ref(dialog);
					tsk_list_push_back_data(self->dialogs, (void**)&dialog);
				}
				break;
			}
		case tsip_dialog_MESSAGE:
			{
				if((dialog = (tsip_dialog_t*)tsip_dialog_message_create(ss))){
					ret = tsk_object_ref(dialog);
					tsk_list_push_back_data(self->dialogs, (void**)&dialog);
				}
				break;
			}
		case tsip_dialog_INFO:
			{
				if((dialog = (tsip_dialog_t*)tsip_dialog_info_create(ss))){
					ret = tsk_object_ref(dialog);
					tsk_list_push_back_data(self->dialogs, (void**)&dialog);
				}
				break;
			}
		case tsip_dialog_OPTIONS:
			{
				if((dialog = (tsip_dialog_t*)tsip_dialog_options_create(ss))){
					ret = tsk_object_ref(dialog);
					tsk_list_push_back_data(self->dialogs, (void**)&dialog);
				}
				break;
			}
		case tsip_dialog_PUBLISH:
			{
				if((dialog = (tsip_dialog_t*)tsip_dialog_publish_create(ss))){
					ret = tsk_object_ref(dialog);
					tsk_list_push_back_data(self->dialogs, (void**)&dialog);
				}
				break;
			}
		case tsip_dialog_REGISTER:
			{
				if((dialog = (tsip_dialog_t*)tsip_dialog_register_create(ss, tsk_null))){
					ret = tsk_object_ref(dialog);
					tsk_list_push_back_data(self->dialogs, (void**)&dialog);
				}
				break;
			}
		case tsip_dialog_SUBSCRIBE:
			{
				if((dialog = (tsip_dialog_t*)tsip_dialog_subscribe_create(ss))){
					ret = tsk_object_ref(dialog);
					tsk_list_push_back_data(self->dialogs, (void**)&dialog);
				}
				break;
			}

		default:
			{
				TSK_DEBUG_ERROR("Dialog type not supported.");
				break;
			}
	}

bail:
	return ret;
}

int tsip_dialog_layer_remove(tsip_dialog_layer_t *self, const tsip_dialog_t *dialog)
{
	if(dialog && self){
		tsip_dialog_type_t regtype = tsip_dialog_REGISTER;
		tsk_safeobj_lock(self);
		
		/* remove the dialog */
		tsk_list_remove_item_by_data(self->dialogs, dialog);
		
		/* whether shutting down? */
		if(self->shutdown.inprogress){
			if(self->shutdown.phase2){ /* Phase 2 (all non-REGISTER and silent dialogs have been removed) */
				if(tsk_list_count(self->dialogs, pred_find_dialog_by_type, &regtype) == 0){
					/* alert only if there is not REGISTER dialog (ignore silents) */
					TSK_DEBUG_INFO("== Shutting down - Phase-2 completed ==");
					tsk_condwait_broadcast(self->shutdown.condwait);
				}
			}
			else{ /* Phase 1 */
				if(tsk_list_count(self->dialogs, pred_find_dialog_by_not_type, &regtype) == 0){
					/* alert only if all dialogs except REGISTER have been removed */
					TSK_DEBUG_INFO("== Shutting down - Phase-1 completed ==");
					tsk_condwait_broadcast(self->shutdown.condwait);
				}
			}
		}

		tsk_safeobj_unlock(self);

		return 0;
	}

	return -1;
}

// this function is only called if no transaction match
// for responses, the transaction will always match
int tsip_dialog_layer_handle_incoming_msg(const tsip_dialog_layer_t *self, tsip_message_t* message)
{
	int ret = -1;
	tsk_bool_t cid_matched;
	tsip_dialog_t* dialog;
	tsip_transac_t* transac = tsk_null;
	const tsip_transac_layer_t *layer_transac = self->stack->layer_transac;

	if(!layer_transac){
		goto bail;
	}
	
	//tsk_safeobj_lock(self);
	dialog = tsip_dialog_layer_find(self, message->Call_ID->value, 
		TSIP_MESSAGE_IS_RESPONSE(message) ? message->To->tag : message->From->tag, 
		TSIP_MESSAGE_IS_RESPONSE(message) ? message->From->tag : message->To->tag, 
		TSIP_MESSAGE_IS_REQUEST(message) ? TSIP_MESSAGE_AS_REQUEST(message)->line.request.request_type : tsip_NONE, 
		&cid_matched);
	//tsk_safeobj_unlock(self);
	
	if(dialog){
		if(TSIP_REQUEST_IS_CANCEL(message) || TSIP_REQUEST_IS_ACK(message)){
			ret = dialog->callback(dialog, tsip_dialog_i_msg, message);
			tsk_object_unref(dialog);
			goto bail;
		}
		else{
			static tsk_bool_t isCT = tsk_false;
			tsip_transac_dst_t* dst = tsip_transac_dst_dialog_create(dialog);
			transac = tsip_transac_layer_new(
				layer_transac, 
				isCT,
				message, 
				dst
			);
			TSK_OBJECT_SAFE_FREE(dst);
			TSK_OBJECT_SAFE_FREE(dialog);
		}
	}
	else{
		/* MediaProxyMode : forward all non-INVITE messages */
		if(self->stack->network.mode == tsip_stack_mode_webrtc2sip){
			tsk_bool_t b2bua;
			
			if(TSIP_MESSAGE_IS_REQUEST(message)){
				// requests received over TCP/TLS/UDP must contain "ws-src-ip" and "ws-src-port" parameters
				if(!TNET_SOCKET_TYPE_IS_WS(message->src_net_type) && !TNET_SOCKET_TYPE_IS_WSS(message->src_net_type)){
					const char* ws_src_ip = tsk_params_get_param_value(message->line.request.uri->params, "ws-src-ip");
					const tnet_port_t ws_src_port = (tnet_port_t)tsk_params_get_param_value_as_int(message->line.request.uri->params, "ws-src-port");
					if(!tsip_transport_layer_have_stream_peer_with_remote_ip(self->stack->layer_transport, ws_src_ip, ws_src_port)){
						if(!TSIP_REQUEST_IS_ACK(message)){ // ACK do not expect response
#if 0 // code commented because when using mjserver, rejecting the forked INVITE terminate all dialogs: have to check if it's conform to RFC 3261 or not
							tsip_response_t* response = tsip_response_new(488, "WebSocket Peer not connected", message);
							ret = tsip_transport_layer_send(self->stack->layer_transport, "no-branch", response);
							TSK_OBJECT_SAFE_FREE(response);
							return ret;
#else
							TSK_DEBUG_INFO("Request for peer at %s:%d cannot be delivered", ws_src_ip, ws_src_port);
#endif
						}
						return 0;
					}
				}
			}

			// "rtcweb-breaker" parameter will be in the Contact header for outgoing request and in the request-uri for incoming requests
			b2bua = TSIP_REQUEST_IS_INVITE(message) && message->Contact && message->Contact->uri &&
					(tsk_striequals(tsk_params_get_param_value(message->Contact->uri->params, "rtcweb-breaker"), "yes")
					|| tsk_striequals(tsk_params_get_param_value(message->line.request.uri->params, "rtcweb-breaker"), "yes"));
			
			if(!b2bua){
				// forward the message
				static tsk_bool_t isCT = tsk_true;
				tsip_transac_dst_t* dst;
				tsip_transac_t* transac;

				TSIP_MESSAGE(message)->update = tsk_true; // update AoR and Via
				if((dst = tsip_transac_dst_net_create(TSIP_STACK(self->stack)))){
					if((transac = tsip_transac_layer_new(self->stack->layer_transac, isCT, message, dst))){
						ret = tsip_transac_start(transac, message);
						TSK_OBJECT_SAFE_FREE(transac);
					}
					TSK_OBJECT_SAFE_FREE(dst);
				}
				return ret;
			}
		}

		if(TSIP_MESSAGE_IS_REQUEST(message)){
			tsip_ssession_t* ss = tsk_null;
			tsip_dialog_t* newdialog = tsk_null;
			
			switch(message->line.request.request_type){
				case tsip_MESSAGE:
					{	/* Server incoming MESSAGE */
						if((ss = tsip_ssession_create_2(self->stack, message))){
							newdialog = (tsip_dialog_t*)tsip_dialog_message_create(ss);
						}
						break;
					}
				case tsip_INFO:
					{	/* Server incoming INFO */
						if((ss = tsip_ssession_create_2(self->stack, message))){
							newdialog = (tsip_dialog_t*)tsip_dialog_info_create(ss);
						}
						break;
					}
				case tsip_OPTIONS:
					{	/* Server incoming OPTIONS */
						if((ss = tsip_ssession_create_2(self->stack, message))){
							newdialog = (tsip_dialog_t*)tsip_dialog_options_create(ss);
						}
						break;
					}

				case tsip_REGISTER:
					{	/* incoming REGISTER */
						if((ss = tsip_ssession_create_2(self->stack, message))){
							newdialog = (tsip_dialog_t*)tsip_dialog_register_create(ss, message->Call_ID ? message->Call_ID->value : tsk_null);
						}
						break;
					}

				case tsip_INVITE:
					{	/* incoming INVITE */
						if((ss = tsip_ssession_create_2(self->stack, message))){
							newdialog = (tsip_dialog_t*)tsip_dialog_invite_create(ss, message->Call_ID ? message->Call_ID->value : tsk_null);
						}
						break;
					}

				default:
					{
						break;
					}
			}//switch

			// for new dialog, create a new transac and start it later
			if(newdialog){
				static const tsk_bool_t isCT = tsk_false;
				tsip_transac_dst_t* dst = tsip_transac_dst_dialog_create(newdialog);
				transac = tsip_transac_layer_new(
					layer_transac, 
					isCT,
					message, 
					dst
				);
				if(message->local_fd > 0 && TNET_SOCKET_TYPE_IS_STREAM(message->src_net_type)) {
					tsip_dialog_set_connected_fd(newdialog, message->local_fd);
				}
				tsk_list_push_back_data(self->dialogs, (void**)&newdialog); /* add new dialog to the layer */
				TSK_OBJECT_SAFE_FREE(dst);
			}

			/* The dialog will become the owner of the SIP session
			* => when destoyed => SIP session will be destroyed, unless the user-end takes ownership() */
			TSK_OBJECT_SAFE_FREE(ss);
		}
	}

	if(transac){
		ret = tsip_transac_start(transac, message);
		tsk_object_unref(transac);
	}
	/* - No transaction match for the SIP request
	   - ACK do not expect any response (http://code.google.com/p/imsdroid/issues/detail?id=420)
	*/
	else if(TSIP_MESSAGE_IS_REQUEST(message) && !TSIP_REQUEST_IS_ACK(message)){
		const tsip_transport_layer_t *layer;
		tsip_response_t* response = tsk_null;
		if(!dialog && cid_matched){
			dialog = tsip_dialog_layer_find_by_callid((tsip_dialog_layer_t *)self, message->Call_ID->value);
		}

		if((layer = self->stack->layer_transport)){	
			if(cid_matched){ /* We are receiving our own message. */
				response = tsip_response_new(482, "Loop Detected (Check your iFCs)", message);
				if(response && !response->To->tag){/* Early dialog? */
					response->To->tag = tsk_strdup("doubango");
				}
			}
			else{
				switch(message->line.request.request_type){
					case tsip_OPTIONS: // Hacked to work on Tiscali IMS networks
					case tsip_INFO:
						response = tsip_response_new(405, "Method Not Allowed", message);
						break;
					default:
						response = tsip_response_new(481, "Dialog/Transaction Does Not Exist", message);
						break;
				}
			}
			if(response){
				if(dialog && TSIP_DIALOG_GET_SS(dialog)){
					tsk_strupdate(&response->sigcomp_id, TSIP_DIALOG_GET_SS(dialog)->sigcomp_id);
				}
				ret = tsip_transport_layer_send(layer, response->firstVia ? response->firstVia->branch : "no-branch", response);
				TSK_OBJECT_SAFE_FREE(response);
			}
		}

		TSK_OBJECT_SAFE_FREE(dialog);
	}
	
bail:
	return ret;
}





//========================================================
//	Dialog layer object definition
//
static tsk_object_t* tsip_dialog_layer_ctor(tsk_object_t * self, va_list * app)
{
	tsip_dialog_layer_t *layer = self;
	if(layer){
		layer->stack = va_arg(*app, const tsip_stack_t *);
		layer->dialogs = tsk_list_create();

		tsk_safeobj_init(layer);
	}
	return self;
}

static tsk_object_t* tsip_dialog_layer_dtor(tsk_object_t * self)
{ 
	tsip_dialog_layer_t *layer = self;
	if(layer){
		TSK_OBJECT_SAFE_FREE(layer->dialogs);

		/* condwait */
		if(layer->shutdown.condwait){
			tsk_condwait_destroy(&layer->shutdown.condwait);
		}

		tsk_safeobj_deinit(layer);

		TSK_DEBUG_INFO("*** Dialog Layer destroyed ***");
	}
	return self;
}

static int tsip_dialog_layer_cmp(const tsk_object_t *obj1, const tsk_object_t *obj2)
{
	return -1;
}

static const tsk_object_def_t tsip_dialog_layer_def_s = 
{
	sizeof(tsip_dialog_layer_t),
	tsip_dialog_layer_ctor, 
	tsip_dialog_layer_dtor,
	tsip_dialog_layer_cmp, 
};
const tsk_object_def_t *tsip_dialog_layer_def_t = &tsip_dialog_layer_def_s;