// [License]
// The Ariba-Underlay Copyright
//
// Copyright (c) 2008-2009, Institute of Telematics, Universität Karlsruhe (TH)
//
// Institute of Telematics
// Universität Karlsruhe (TH)
// Zirkel 2, 76128 Karlsruhe
// Germany
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE INSTITUTE OF TELEMATICS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ARIBA PROJECT OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// The views and conclusions contained in the software and documentation
// are those of the authors and should not be interpreted as representing
// official policies, either expressed or implied, of the Institute of
// Telematics.
// [License]

#include "BaseOverlay.h"

#include <sstream>
#include <iostream>
#include <string>
#include <boost/foreach.hpp>

#include "ariba/NodeListener.h"
#include "ariba/CommunicationListener.h"
#include "ariba/SideportListener.h"

#include "ariba/overlay/LinkDescriptor.h"
#include "ariba/overlay/messages/OverlayMsg.h"
#include "ariba/overlay/messages/JoinRequest.h"
#include "ariba/overlay/messages/JoinReply.h"
#include "ariba/overlay/messages/LinkRequest.h"
#include "ariba/overlay/messages/RelayMessage.h"

#include "ariba/utility/misc/OvlVis.h"

namespace ariba {
namespace overlay {

LinkDescriptor* BaseOverlay::getDescriptor( const LinkID& link, bool communication ) {
	BOOST_FOREACH( LinkDescriptor* lp, links )
		if ((communication ? lp->communicationId : lp->overlayId) == link)
			return lp;
	return NULL;
}

const LinkDescriptor* BaseOverlay::getDescriptor( const LinkID& link, bool communication ) const {
	BOOST_FOREACH( const LinkDescriptor* lp, links )
		if ((communication ? lp->communicationId : lp->overlayId) == link)
			return lp;
	return NULL;
}

LinkDescriptor* BaseOverlay::getAutoDescriptor( const NodeID& node, const ServiceID& service ) {
	BOOST_FOREACH( LinkDescriptor* lp, links )
		if (lp->autolink && lp->remoteNode == node && lp->service == service)
			return lp;
	return NULL;
}

void BaseOverlay::eraseDescriptor( const LinkID& link, bool communication ) {
	for ( vector<LinkDescriptor*>::iterator i = links.begin(); i!= links.end(); i++) {
		LinkDescriptor* ld = *i;
		if ((communication ? ld->communicationId : ld->overlayId) == link) {
			delete ld;
			links.erase(i);
			break;
		}
	}
}

LinkDescriptor* BaseOverlay::addDescriptor( const LinkID& link ) {
	LinkDescriptor* desc = getDescriptor( link );
	if ( desc == NULL ) {
		desc = new LinkDescriptor();
		desc->overlayId = link;
		links.push_back(desc);
	}
	return desc;
}

/// returns a direct link relay descriptor to the given relay node
LinkDescriptor* BaseOverlay::getRelayDescriptor( const NodeID& relayNode ) {
	BOOST_FOREACH( LinkDescriptor* lp, links )
		if (lp->remoteNode == relayNode &&
		    lp->service == OverlayInterface::OVERLAY_SERVICE_ID &&
		    lp->relay == false &&
		    lp->up)
			return lp;
	return NULL;
}

/// find a proper relay node
const NodeID BaseOverlay::findRelayNode( const NodeID& id ) {
	LinkDescriptor* rld = NULL;
	NodeID relayNode = NodeID::UNSPECIFIED;

	// get used next hop towards node
	LinkID rlid = overlayInterface->getNextLinkId(id);
	while ( relayNode.isUnspecified() && !rlid.isUnspecified() && rld == NULL ) {

		// get descriptor of first hop
		rld = getDescriptor(rlid);
		logging_force( rld );

		// is first hop a relay path? yes-> try to find real link!
		if ( rld->relay )
			relayNode = getRelayDescriptor(rld->localRelay)->remoteNode;

		// no-> a proper relay node has been found
		else relayNode = rld->remoteNode;
	}
	logging_force( "Potential relay node " << relayNode.toString() );
	// do not return myself or use the node as relay node
	if (relayNode == nodeId)
		return NodeID::UNSPECIFIED;
	else {
		logging_force( "Returning relay node " << relayNode.toString() );
		return relayNode;
	}
}

/// forwards a message over relays/directly using link descriptor
seqnum_t BaseOverlay::sendMessage( Message* message, const LinkDescriptor* ld ) {

	// directly send message
	if ( !ld->communicationId.isUnspecified() && ld->communicationUp ) {
		logging_debug("Send: Sending message via Base Communication");
		return bc->sendMessage( ld->communicationId, message );
	}

	// relay message
	else if ( ld->relay ) {

		logging_debug("Send: Relaying message to node "
			<< ld->remoteNode.toString()
			<< " using relay " << ld->localRelay
		);

		// get local relay link descriptor and mark as used for relaying
		LinkDescriptor* rld = getRelayDescriptor(ld->localRelay);
		if (rld==NULL) {
			logging_error("Send: Relay descriptor for relay " <<
				ld->localRelay.toString() << " is unknown.");
			return -1;
		}
		rld->markAsRelay();

		// create a information relay message to inform the relay about
		OverlayMsg overlay_msg( OverlayMsg::typeRelay, ld->service, nodeId );
		RelayMessage relayMsg( RelayMessage::typeInform, ld->remoteRelay, ld->remoteNode, ld->remoteLinkId );
		relayMsg.encapsulate( message );
		overlay_msg.encapsulate( &relayMsg );

		// route message to relay node in order to inform it!
		logging_debug("sendMessage: Sending message over relayed link with" << ld );
		overlayInterface->routeMessage(rld->remoteNode, rld->overlayId, &overlay_msg);
		return 0;
	}

	// error
	else {
		logging_error( "Could not send message descriptor=" << ld );
		return -1;
	}
	return -1;
}

/// creates a link descriptor, apply relay semantics if possible
LinkDescriptor* BaseOverlay::createLinkDescriptor(
	const NodeID& remoteNode, const ServiceID& service, const LinkID& link_id ) {

	// find listener
	if( !communicationListeners.contains( service ) ) {
		logging_error( "No listener found for service " << service.toString() );
		return NULL;
	}
	CommunicationListener* listener = communicationListeners.get( service );
	assert( listener != NULL );

	// copy link id
	LinkID linkid = link_id;

	// create link id if necessary
	if ( linkid.isUnspecified() )
		linkid = LinkID::create();

	// create relay link descriptor
	NodeID relayNode = findRelayNode(remoteNode);

	// add descriptor
	LinkDescriptor* ld = addDescriptor( linkid );
	ld->overlayId  = linkid;
	ld->service    = service;
	ld->listener   = listener;
	ld->remoteNode = remoteNode;

	// set relay node if available
	ld->relay      = !relayNode.isUnspecified();
	ld->localRelay = relayNode;

	if (!ld->relay)
		logging_error("No relay found!");

	// debug output
	logging_debug( "Created link descriptor: " << ld );

	return ld;
}


// ----------------------------------------------------------------------------

use_logging_cpp(BaseOverlay);

// ----------------------------------------------------------------------------

BaseOverlay::BaseOverlay() :
	bc(NULL), overlayInterface(NULL), nodeId(NodeID::UNSPECIFIED),
	spovnetId(SpoVNetID::UNSPECIFIED), state(BaseOverlayStateInvalid),
	sideport(&SideportListener::DEFAULT), started(false) {
}

BaseOverlay::~BaseOverlay() {
}

// ----------------------------------------------------------------------------

void BaseOverlay::start( BaseCommunication& _basecomm, const NodeID& _nodeid ) {
	logging_info("Starting...");

	// set parameters
	bc = &_basecomm;
	nodeId = _nodeid;

	// register at base communication
	bc->registerMessageReceiver( this );
	bc->registerEventListener( this );

	// timer for auto link management
	Timer::setInterval( 500 );
	Timer::start();

	started = true;
	state = BaseOverlayStateInvalid;
}

void BaseOverlay::stop() {
	logging_info("Stopping...");

	// stop timer
	Timer::stop();

	// delete oberlay interface
	if(overlayInterface != NULL) {
		delete overlayInterface;
		overlayInterface = NULL;
	}

	// unregister at base communication
	bc->unregisterMessageReceiver( this );
	bc->unregisterEventListener( this );

	started = false;
	state = BaseOverlayStateInvalid;
}

bool BaseOverlay::isStarted(){
	return started;
}

// ----------------------------------------------------------------------------

void BaseOverlay::joinSpoVNet(const SpoVNetID& id,
		const EndpointDescriptor& bootstrapEp) {

	if(id != spovnetId){
		logging_error("attempt to join against invalid spovnet, call initiate first");
		return;
	}


	//ovl.visShowNodeBubble ( ovlId, nodeId, "joining..." );
	logging_info( "Starting to join spovnet " << id.toString() <<
			" with nodeid " << nodeId.toString());

	if(bootstrapEp.isUnspecified() && state == BaseOverlayStateInvalid){

		// bootstrap against ourselfs
		logging_debug("joining spovnet locally");

		overlayInterface->joinOverlay();
		state = BaseOverlayStateCompleted;
		BOOST_FOREACH( NodeListener* i, nodeListeners )
			i->onJoinCompleted( spovnetId );

		//ovl.visChangeNodeIcon ( ovlId, nodeId, OvlVis::ICON_ID_CAMERA );
		//ovl.visChangeNodeColor( ovlId, nodeId, OvlVis::NODE_COLORS_GREEN );

		logging_debug("starting overlay bootstrap module");
		overlayBootstrap.start(this, spovnetId, nodeId);
		overlayBootstrap.publish(bc->getEndpointDescriptor());

	} else {

		// bootstrap against another node
		logging_debug("joining spovnet remotely against " << bootstrapEp.toString());

		const LinkID& lnk = bc->establishLink( bootstrapEp );
		bootstrapLinks.push_back(lnk);
		logging_info("join process initiated for " << id.toString() << "...");
	}
}

void BaseOverlay::leaveSpoVNet() {

	logging_info( "Leaving spovnet " << spovnetId );
	bool ret = ( state != this->BaseOverlayStateInvalid );

	logging_debug("stopping overlay bootstrap module");
	overlayBootstrap.stop();
	overlayBootstrap.revoke();

	logging_debug( "Dropping all auto-links" );

	// gather all service links
	vector<LinkID> servicelinks;
	BOOST_FOREACH( LinkDescriptor* ld, links ) {
		if( ld->service != OverlayInterface::OVERLAY_SERVICE_ID )
		servicelinks.push_back( ld->overlayId );
	}

	// drop all service links
	BOOST_FOREACH( LinkID lnk, servicelinks )
		dropLink( lnk );

	// let the node leave the spovnet overlay interface
	logging_debug( "Leaving overlay" );
	if( overlayInterface != NULL )
		overlayInterface->leaveOverlay();

	// drop still open bootstrap links
	BOOST_FOREACH( LinkID lnk, bootstrapLinks )
		bc->dropLink( lnk );

	// change to inalid state
	state = BaseOverlayStateInvalid;
	//ovl.visShutdown( ovlId, nodeId, string("") );

	// inform all registered services of the event
	BOOST_FOREACH( NodeListener* i, nodeListeners ) {
		if( ret ) i->onLeaveCompleted( spovnetId );
		else i->onLeaveFailed( spovnetId );
	}
}

void BaseOverlay::createSpoVNet(const SpoVNetID& id,
		const OverlayParameterSet& param,
		const SecurityParameterSet& sec,
		const QoSParameterSet& qos) {

	// set the state that we are an initiator, this way incoming messages are
	// handled correctly
	logging_info( "creating spovnet " + id.toString() <<
			" with nodeid " << nodeId.toString() );

	spovnetId = id;

	overlayInterface = OverlayFactory::create( *this, param, nodeId, this );
	if( overlayInterface == NULL ) {
		logging_fatal( "overlay structure not supported" );
		state = BaseOverlayStateInvalid;

		BOOST_FOREACH( NodeListener* i, nodeListeners )
			i->onJoinFailed( spovnetId );

		return;
	}
}

// ----------------------------------------------------------------------------

const LinkID BaseOverlay::establishLink(
	const EndpointDescriptor& ep, const NodeID& nodeid,
	const ServiceID& service, const LinkID& linkid ) {

	LinkID link_id = linkid;

	// establish link via overlay
	if (!nodeid.isUnspecified())
		link_id = establishLink( nodeid, service, link_id );

	// establish link directly if only ep is known
	if (nodeid.isUnspecified())
		establishLink( ep, service, link_id );

	return link_id;
}

/// call base communication's establish link and add link mapping
const LinkID BaseOverlay::establishLink( const EndpointDescriptor& ep,
		const ServiceID& service, const LinkID& linkid ) {

	// create a new link id if necessary
	LinkID link_id = linkid;
	if (link_id.isUnspecified()) link_id = LinkID::create();

	/// find a service listener
	if( !communicationListeners.contains( service ) ) {
		logging_error( "No listener registered for service id=" << service.toString() );
		return LinkID::UNSPECIFIED;
	}
	CommunicationListener* listener = communicationListeners.get( service );
	assert( listener != NULL );

	/// establish link and add mapping
	logging_info("Establishing direct link " << link_id.toString()
		<< " using " << ep.toString());

	// create descriptor
	LinkDescriptor* ld = addDescriptor( link_id );
	ld->overlayId = link_id;
	ld->communicationId = link_id;
	ld->listener = listener;
	ld->service = service;
	bc->establishLink( ep, link_id );

	return link_id;
}

/// establishes a link between two arbitrary nodes
const LinkID BaseOverlay::establishLink( const NodeID& node,
		const ServiceID& service, const LinkID& link_id ) {

	// do not establish a link to myself!
	if (node == nodeId) return LinkID::UNSPECIFIED;

	// create a link descriptor
	LinkDescriptor* ld = createLinkDescriptor( node, service, link_id );

	// create link request message with own link id
	uint32_t nonce = (uint32_t)(rand() ^ (rand() << 16) ^ time(NULL));
	LinkRequest link_request_msg(
		nonce, &bc->getEndpointDescriptor(), false,
		ld->overlayId, ld->localRelay );
	OverlayMsg overlay_msg( OverlayMsg::typeLinkRequest, service, nodeId );
	overlay_msg.encapsulate( &link_request_msg );
	pendingLinks.insert( make_pair(nonce, ld->overlayId) );

	// debug message
	logging_debug(
		"Sending link request with"
		<< " link id="        << ld->overlayId
		<< " node id="        << ld->remoteNode.toString()
		<< " service id="     << ld->service.toString()
		<< " local relay id=" << ld->localRelay.toString()
		<< " nonce= "         << nonce
	);

	// sending message through new link
	sendMessage( &overlay_msg, ld );

	return ld->overlayId;
}

/// drops an established link
void BaseOverlay::dropLink(const LinkID& link) {
	logging_debug( "Dropping link (initiated locally):" << link.toString() );

	// find the link item to drop
	LinkDescriptor* ld = getDescriptor(link);
	if( ld == NULL ) {
		logging_warn( "Can't drop link, link is unknown!");
		return;
	}

	// delete all queued messages
	if( ld->messageQueue.size() > 0 ) {
		logging_warn( "Dropping link " << ld->overlayId.toString() << " that has "
				<< ld->messageQueue.size() << " waiting messages" );
		ld->flushQueue();
	}

	// inform sideport and listener
	ld->listener->onLinkDown( ld->overlayId, ld->remoteNode );
	sideport->onLinkDown(ld->overlayId, this->nodeId, ld->remoteNode, this->spovnetId );

	// do not drop relay links
	if (!ld->usedAsRelay) {
		// drop the link in base communication
		if (ld->communicationUp) bc->dropLink( ld->communicationId );

		// erase descriptor
		eraseDescriptor( ld->overlayId );
	} else
		ld->dropWhenRelaysLeft = true;
}

// ----------------------------------------------------------------------------

/// internal send message, always use this functions to send messages over links
seqnum_t BaseOverlay::sendMessage( const Message* message, const LinkID& link ) {
	logging_debug( "Sending data message on link " << link.toString() );

	// get the mapping for this link
	LinkDescriptor* ld = getDescriptor(link);
	if( ld == NULL ) {
		logging_error("Could not send message. "
			<< "Link not found id=" << link.toString());
		return -1;
	}

	// check if the link is up yet, if its an auto link queue message
	if( !ld->up ) {
		ld->markAsUsed();
		if( ld->autolink ) {
			logging_info("Auto-link " << link.toString() << " not up, queue message");
			Data data = data_serialize( message );
			const_cast<Message*>(message)->dropPayload();
			ld->messageQueue.push_back( new Message(data) );
		} else {
			logging_error("Link " << link.toString() << " not up, drop message");
		}
		return -1;
	}

	// compile overlay message (has service and node id)
	OverlayMsg overmsg( OverlayMsg::typeData, ld->service, nodeId );
	overmsg.encapsulate( const_cast<Message*>(message) );

	// send message over relay/direct/overlay
	return sendMessage( &overmsg, ld );
}

seqnum_t BaseOverlay::sendMessage(const Message* message,
	const NodeID& node, const ServiceID& service) {

	// find link for node and service
	LinkDescriptor* ld = getAutoDescriptor( node, service );

	// if we found no link, create an auto link
	if( ld == NULL ) {

		// debug output
		logging_info( "No link to send message to node "
			<< node.toString() << " found for service "
			<< service.toString() << ". Creating auto link ..."
		);

		// this will call onlinkup on us, if everything worked we now have a mapping
		LinkID link = LinkID::create();

		// call base overlay to create a link
		link = establishLink( node, service, link );
		ld = getDescriptor( link );
		if( ld == NULL ) {
			logging_error( "Failed to establish auto-link.");
			return -1;
		}
		ld->autolink = true;

		logging_debug( "Auto-link establishment in progress to node "
				<< node.toString() << " with link id=" << link.toString() );
	}
	assert(ld != NULL);

	// mark the link as used, as we now send a message through it
	ld->markAsUsed();

	// send / queue message
	return sendMessage( message, ld->overlayId );
}

// ----------------------------------------------------------------------------

const EndpointDescriptor& BaseOverlay::getEndpointDescriptor(
		const LinkID& link) const {

	// return own end-point descriptor
	if( link == LinkID::UNSPECIFIED )
		return bc->getEndpointDescriptor();

	// find link descriptor. not found -> return unspecified
	const LinkDescriptor* ld = getDescriptor(link);
	if (ld==NULL) return EndpointDescriptor::UNSPECIFIED;

	// return endpoint-descriptor from base communication
	return bc->getEndpointDescriptor( ld->communicationId );
}

const EndpointDescriptor& BaseOverlay::getEndpointDescriptor(
		const NodeID& node) const {

	// return own end-point descriptor
	if( node == nodeId || node == NodeID::UNSPECIFIED )
		return bc->getEndpointDescriptor();

	// no joined and request remote descriptor? -> fail!
	if( overlayInterface == NULL ) {
		logging_error( "overlay interface not set, cannot resolve endpoint" );
		return EndpointDescriptor::UNSPECIFIED;
	}

	// resolve end-point descriptor from the base-overlay routing table
	return overlayInterface->resolveNode( node );
}

// ----------------------------------------------------------------------------

bool BaseOverlay::registerSidePort(SideportListener* _sideport) {
	sideport = _sideport;
	_sideport->configure( this );
}

bool BaseOverlay::unregisterSidePort(SideportListener* _sideport) {
	sideport = &SideportListener::DEFAULT;
}

// ----------------------------------------------------------------------------

bool BaseOverlay::bind(CommunicationListener* listener, const ServiceID& sid) {
	logging_debug( "binding communication listener " << listener
			<< " on serviceid " << sid.toString() );

	if( communicationListeners.contains( sid ) ) {
		logging_error( "some listener already registered for service id "
				<< sid.toString() );
		return false;
	}

	communicationListeners.registerItem( listener, sid );
	return true;
}


bool BaseOverlay::unbind(CommunicationListener* listener, const ServiceID& sid) {
	logging_debug( "unbinding listener " << listener << " from serviceid " << sid.toString() );

	if( !communicationListeners.contains( sid ) ) {
		logging_warn( "cannot unbind listener. no listener registered on service id " << sid.toString() );
		return false;
	}

	if( communicationListeners.get(sid) != listener ) {
		logging_warn( "listener bound to service id " << sid.toString()
				<< " is different than listener trying to unbind" );
		return false;
	}

	communicationListeners.unregisterItem( sid );
	return true;
}

// ----------------------------------------------------------------------------

bool BaseOverlay::bind(NodeListener* listener) {
	logging_debug( "Binding node listener " << listener );

	// already bound? yes-> warning
	NodeListenerVector::iterator i =
		find( nodeListeners.begin(), nodeListeners.end(), listener );
	if( i != nodeListeners.end() ) {
		logging_warn("Node listener " << listener << " is already bound!" );
		return false;
	}

	// no-> add
	nodeListeners.push_back( listener );
	return true;
}

bool BaseOverlay::unbind(NodeListener* listener) {
	logging_debug( "Unbinding node listener " << listener );

	// already unbound? yes-> warning
	NodeListenerVector::iterator i = find( nodeListeners.begin(), nodeListeners.end(), listener );
	if( i == nodeListeners.end() ) {
		logging_warn( "Node listener " << listener << " is not bound!" );
		return false;
	}

	// no-> remove
	nodeListeners.erase( i );
	return true;
}

// ----------------------------------------------------------------------------

void BaseOverlay::onLinkUp(const LinkID& id,
	const address_v* local, const address_v* remote) {
	logging_debug( "Link up with base communication link id=" << id );

	// get descriptor for link
	LinkDescriptor* ld = getDescriptor(id, true);

	// handle bootstrap link we initiated
	if( std::find(bootstrapLinks.begin(), bootstrapLinks.end(), id) != bootstrapLinks.end() ){
		logging_info(
			"Join has been initiated by me and the link is now up. " <<
			"Sending out join request for SpoVNet " << spovnetId.toString()
		);

		// send join request message
		OverlayMsg overlayMsg( OverlayMsg::typeJoinRequest, nodeId );
		JoinRequest joinRequest( spovnetId, nodeId );
		overlayMsg.encapsulate( &joinRequest );
		bc->sendMessage( id, &overlayMsg );
		return;
	}

	// no link found? -> link establishment from remote, add one!
	if (ld == NULL) {
		ld = addDescriptor( id );
		logging_debug( "onLinkUp (remote request) descriptor: " << ld );

		// update descriptor
		ld->fromRemote = true;
		ld->communicationId = id;
		ld->communicationUp = true;
		ld->markAsUsed();

		// in this case, do not inform listener, since service it unknown
		// -> wait for update message!

	// link mapping found? -> send update message with node-id and service id
	} else {
		logging_debug( "onLinkUp descriptor (initiated locally):" << ld );

		// note: necessary to validate the link on the remote side!
		logging_debug( "Sending out update" <<
			" for service " << ld->service.toString() <<
			" with local node id " << nodeId.toString() <<
			" on link " << ld->overlayId.toString() );

		// update descriptor
		ld->markAsUsed();
		ld->communicationUp = true;

		// if link is a relayed link ->convert to direct link
		if (ld->relay) {
			logging_force( "Converting to direct link: " << ld );
			ld->up = true;
			ld->relay = false;
			ld->localRelay = NodeID::UNSPECIFIED;
			OverlayMsg overMsg( OverlayMsg::typeDirectLink, ld->service, nodeId );
			overMsg.setRelayLink( ld->remoteLinkId );
			bc->sendMessage( ld->communicationId, &overMsg );
		}

		// compile and send update message
		OverlayMsg overlayMsg( OverlayMsg::typeUpdate, ld->service, nodeId );
		overlayMsg.setAutoLink( ld->autolink );
		bc->sendMessage( ld->communicationId, &overlayMsg );
	}
}

void BaseOverlay::onLinkDown(const LinkID& id,
	const address_v* local, const address_v* remote) {

	// erase bootstrap links
	vector<LinkID>::iterator it = std::find( bootstrapLinks.begin(), bootstrapLinks.end(), id );
	if( it != bootstrapLinks.end() ) bootstrapLinks.erase( it );

	// get descriptor for link
	LinkDescriptor* ld = getDescriptor(id, true);
	if ( ld == NULL ) return; // not found? ->ignore!
	logging_force( "onLinkDown descriptor: " << ld );

	// inform listeners about link down
	ld->communicationUp = false;
	ld->listener->onLinkDown( ld->overlayId, ld->remoteNode );
	sideport->onLinkDown( id, this->nodeId, ld->remoteNode, this->spovnetId );

	// delete all queued messages (auto links)
	if( ld->messageQueue.size() > 0 ) {
		logging_warn( "Dropping link " << id.toString() << " that has "
				<< ld->messageQueue.size() << " waiting messages" );
		ld->flushQueue();
	}

	// erase mapping
	eraseDescriptor(ld->overlayId);
}

void BaseOverlay::onLinkChanged(const LinkID& id,
	const address_v* oldlocal, const address_v* newlocal,
	const address_v* oldremote, const address_v* newremote) {

	// get descriptor for link
	LinkDescriptor* ld = getDescriptor(id, true);
	if ( ld == NULL ) return; // not found? ->ignore!
	logging_debug( "onLinkChanged descriptor: " << ld );

	// inform listeners
	ld->listener->onLinkChanged( ld->overlayId, ld->remoteNode );
	sideport->onLinkChanged( id, this->nodeId, ld->remoteNode, this->spovnetId );

	// autolinks: refresh timestamp
	ld->markAsUsed();
}

void BaseOverlay::onLinkFail(const LinkID& id,
	const address_v* local, const address_v* remote) {
	logging_debug( "Link fail with base communication link id=" << id );

	// erase bootstrap links
	vector<LinkID>::iterator it = std::find( bootstrapLinks.begin(), bootstrapLinks.end(), id );
	if( it != bootstrapLinks.end() ) bootstrapLinks.erase( it );

	// get descriptor for link
	LinkDescriptor* ld = getDescriptor(id, true);
	if ( ld == NULL ) return; // not found? ->ignore!
	logging_debug( "Link failed id=" << ld->overlayId.toString() );

	// inform listeners
	ld->listener->onLinkFail( ld->overlayId, ld->remoteNode );
	sideport->onLinkFail( id, this->nodeId, ld->remoteNode, this->spovnetId );

	// autolinks: refresh timestamp
	ld->markAsUsed();
}

void BaseOverlay::onLinkQoSChanged(const LinkID& id, const address_v* local,
	const address_v* remote, const QoSParameterSet& qos) {
	logging_debug( "Link quality changed with base communication link id=" << id );

	// get descriptor for link
	LinkDescriptor* ld = getDescriptor(id, true);
	if ( ld == NULL ) return; // not found? ->ignore!
	logging_debug( "Link quality changed id=" << ld->overlayId.toString() );

	// autolinks: refresh timestamp
	ld->markAsUsed();
}

bool BaseOverlay::onLinkRequest( const LinkID& id, const address_v* local,
	const address_v* remote ) {
	logging_debug("Accepting link request from " << remote->to_string() );
	return true;
}

/// handles a message from base communication
bool BaseOverlay::receiveMessage(const Message* message,
		const LinkID& link, const NodeID& ) {
	// get descriptor for link
	LinkDescriptor* ld = getDescriptor( link, true );

	// link known?
	if (ld == NULL) { // no-> handle with unspecified params
		logging_debug("Received message from base communication, link descriptor unknown" );
		return handleMessage( message, LinkID::UNSPECIFIED, link, NodeID::UNSPECIFIED );
	} else { // yes -> handle with overlay link id
		logging_debug("Received message from base communication, link id=" << ld->overlayId.toString() );
		return handleMessage( message, ld->overlayId, link, NodeID::UNSPECIFIED );
	}
}

// ----------------------------------------------------------------------------

/// handles a message from an overlay
void BaseOverlay::incomingRouteMessage( Message* msg, const LinkID& link, const NodeID& source ) {
	logging_debug("Received message from overlay -- "
		<< " link id=" << link.toString()
		<< " node id=" << source.toString() );
	handleMessage( msg, link, LinkID::UNSPECIFIED, source );
}

// ----------------------------------------------------------------------------

/// handles an incoming message
bool BaseOverlay::handleMessage( const Message* message,
	const LinkID& boLink, const LinkID& bcLink, const NodeID& remoteNode ) {
	logging_debug( "Handling message: " << message->toString());

	// decapsulate overlay message
	OverlayMsg* overlayMsg =
		const_cast<Message*>(message)->decapsulate<OverlayMsg>();
	if( overlayMsg == NULL ) return false;

	// mark the link as in action
	LinkDescriptor* ld = getDescriptor(boLink);
	if (ld == NULL) ld = getDescriptor(bcLink, true);
	if (ld != NULL) {
		ld->markAsUsed();
		ld->markAlive();
	}

	switch ( overlayMsg->getType() ) {
		// ---------------------------------------------------------------------
		// Handle spovnet instance join requests
		// ---------------------------------------------------------------------
		case OverlayMsg::typeJoinRequest: {

			// decapsulate message
			JoinRequest* joinReq = overlayMsg->decapsulate<JoinRequest>();
			logging_info( "Received join request for spovnet " <<
					joinReq->getSpoVNetID().toString() );

			// check spovnet id
			if( joinReq->getSpoVNetID() != spovnetId ) {
				logging_error(
					"Received join request for spovnet we don't handle " <<
					joinReq->getSpoVNetID().toString() );
				return false;
			}

			// TODO: here you can implement mechanisms to deny joining of a node
			bool allow = true;
			logging_info( "Sending join reply for spovnet " <<
					spovnetId.toString() << " to node " <<
					overlayMsg->getSourceNode().toString() <<
					". Result: " << (allow ? "allowed" : "denied") );
			joiningNodes.push_back( overlayMsg->getSourceNode() );

			// return overlay parameters
			assert( overlayInterface != NULL );
			logging_debug( "Using bootstrap end-point "
				<< getEndpointDescriptor().toString() )
			OverlayParameterSet parameters = overlayInterface->getParameters();
			OverlayMsg retmsg( OverlayMsg::typeJoinReply, nodeId );
			JoinReply replyMsg( spovnetId, parameters,
					allow, getEndpointDescriptor() );
			retmsg.encapsulate(&replyMsg);
			bc->sendMessage( bcLink, &retmsg );
			return true;
		}

		// ---------------------------------------------------------------------
		// handle replies to spovnet instance join requests
		// ---------------------------------------------------------------------
		case OverlayMsg::typeJoinReply: {

			// decapsulate message
			logging_debug("received join reply message");
			JoinReply* replyMsg = overlayMsg->decapsulate<JoinReply>();

			// correct spovnet?
			if( replyMsg->getSpoVNetID() != spovnetId ) { // no-> fail
				logging_error( "Received SpoVNet join reply for " <<
						replyMsg->getSpoVNetID().toString() <<
						" != " << spovnetId.toString() );
				return false;
			}

			// access granted? no -> fail
			if( !replyMsg->getJoinAllowed() ) {
				logging_error( "Our join request has been denied" );

				// drop initiator link

				if(bcLink != LinkID::UNSPECIFIED){
					bc->dropLink( bcLink );

					vector<LinkID>::iterator it = std::find(
							bootstrapLinks.begin(), bootstrapLinks.end(), bcLink);
					if( it != bootstrapLinks.end() )
						bootstrapLinks.erase(it);
				}

				// inform all registered services of the event
				BOOST_FOREACH( NodeListener* i, nodeListeners )
					i->onJoinFailed( spovnetId );

				return true;
			}

			// access has been granted -> continue!
			logging_info("Join request has been accepted for spovnet " <<
					spovnetId.toString() );

			logging_debug( "Using bootstrap end-point "
				<< replyMsg->getBootstrapEndpoint().toString() );

			//
			// create overlay structure from spovnet parameter set
			// if we have not boostrapped yet against some other node
			//

			if( overlayInterface == NULL ){

				logging_debug("first-time bootstrapping");

				overlayInterface = OverlayFactory::create(
					*this, replyMsg->getParam(), nodeId, this );

				// overlay structure supported? no-> fail!
				if( overlayInterface == NULL ) {
					logging_error( "overlay structure not supported" );

					if(bcLink != LinkID::UNSPECIFIED){
						bc->dropLink( bcLink );

						vector<LinkID>::iterator it = std::find(
								bootstrapLinks.begin(), bootstrapLinks.end(), bcLink);
						if( it != bootstrapLinks.end() )
							bootstrapLinks.erase(it);
					}

					// inform all registered services of the event
					BOOST_FOREACH( NodeListener* i, nodeListeners )
					i->onJoinFailed( spovnetId );

					return true;
				}

				// everything ok-> join the overlay!
				state = BaseOverlayStateCompleted;
				overlayInterface->createOverlay();

				overlayInterface->joinOverlay( replyMsg->getBootstrapEndpoint() );

				// update ovlvis
				//ovl.visChangeNodeColor( ovlId, nodeId, OvlVis::NODE_COLORS_GREEN);

				// inform all registered services of the event
				BOOST_FOREACH( NodeListener* i, nodeListeners )
					i->onJoinCompleted( spovnetId );

			} else {

				// this is not the first bootstrap, just join the additional node
				logging_debug("not first-time bootstrapping");
				overlayInterface->joinOverlay( replyMsg->getBootstrapEndpoint() );

			} // if( overlayInterface == NULL )

			return true;
		}

		// ---------------------------------------------------------------------
		// handle data forward messages
		// ---------------------------------------------------------------------
		case OverlayMsg::typeData: {

			// get service
			const ServiceID& service = overlayMsg->getService();
			logging_debug( "received data for service " << service.toString() );

			// find listener
			CommunicationListener* listener =
				communicationListeners.get( service );
			if( listener == NULL ) return true;

			// delegate data message
			listener->onMessage( overlayMsg,
				overlayMsg->getSourceNode(), ld->overlayId );

			return true;
		}

		// ---------------------------------------------------------------------
		// handle update messages for link establishment
		// ---------------------------------------------------------------------
		case OverlayMsg::typeUpdate: {
			logging_debug("Received type update message on link " << ld );

			// get info
			const NodeID& sourcenode = overlayMsg->getSourceNode();
			const ServiceID& service = overlayMsg->getService();

			// no link descriptor available -> error!
			if( ld == NULL ) {
				logging_warn( "received overlay update message for link " <<
						ld->overlayId.toString() << " for which we have no mapping" );
				return false;
			}

			// update our link mapping information for this link
			bool changed =
				( ld->remoteNode != sourcenode ) || ( ld->service != service );
			ld->remoteNode = sourcenode;
			ld->service = service;
			ld->autolink = overlayMsg->isAutoLink();

			// if our link information changed, we send out an update, too
			if( changed ) {
				OverlayMsg overMsg( OverlayMsg::typeUpdate, ld->service, nodeId );
				overMsg.setAutoLink(ld->autolink);
				bc->sendMessage( ld->communicationId, &overMsg );
			}

			// service registered? no-> error!
			if( !communicationListeners.contains( service ) ) {
				logging_warn( "Link up: event listener has not been registered" );
				return false;
			}

			// default or no service registered?
			CommunicationListener* listener = communicationListeners.get( service );
			if( listener == NULL || listener == &CommunicationListener::DEFAULT ) {
				logging_warn("Link up: event listener is default or null!" );
				return true;
			}

			// update descriptor
			ld->listener = listener;
			ld->markAsUsed();
			ld->markAlive();

			// ask the service whether it wants to accept this link
			if( !listener->onLinkRequest(sourcenode) ) {

				logging_debug("Link id=" << ld->overlayId.toString() <<
					" has been denied by service " << service.toString() << ", dropping link");

				// prevent onLinkDown calls to the service
				ld->listener = &CommunicationListener::DEFAULT;

				// drop the link
				dropLink( ld->overlayId );
				return true;
			}

			// set link up
			ld->up = true;
			logging_debug(
				   "Link " << ld->overlayId.toString()
				<< " has been accepted by service " << service.toString()
				<< " and is now up"
			);

			// auto links: link has been accepted -> send queued messages
			if( ld->messageQueue.size() > 0 ) {
				logging_info( "sending out queued messages on link " <<
					ld->overlayId.toString() );
				BOOST_FOREACH( Message* msg, ld->messageQueue ) {
					sendMessage( msg, ld->overlayId );
					delete msg;
				}
				ld->messageQueue.clear();
			}

			// call the notification functions
			listener->onLinkUp( ld->overlayId, sourcenode );
			sideport->onLinkUp( ld->overlayId, nodeId, sourcenode, this->spovnetId );

			return true;
		}

		// ---------------------------------------------------------------------
		// handle link request forwarded through the overlay
		// ---------------------------------------------------------------------
		case OverlayMsg::typeLinkRequest: {

			logging_debug( "received link request on link" );

			// decapsulate message
			LinkRequest* linkReq = overlayMsg->decapsulate<LinkRequest>();
			const ServiceID& service = overlayMsg->getService();

			// is request reply?
			if ( linkReq->isReply() ) {

				// find link
				PendingLinkMap::iterator i = pendingLinks.find( linkReq->getNonce() );
				if ( i == pendingLinks.end() ) {
					logging_error( "Nonce not found in link request" );
					return true;
				}

				// debug message
				logging_debug( "Link request reply received. Establishing link "
					<< i->second << " to " << (linkReq->getEndpoint()->toString())
					<< " for service " << service.toString()
					<< " with nonce "  << linkReq->getNonce()
					<< " using relay " << linkReq->getRelay().toString()
					<< " and remote link id=" << linkReq->getRemoteLinkId()
				);

				// get descriptor
				LinkDescriptor* ldn = getDescriptor(i->second);

				// check if link request reply has a relay node ...
				if (!linkReq->getRelay().isUnspecified()) { // yes->
					ldn->up = true;
					ldn->relay = true;
					if (ldn->localRelay.isUnspecified())  {
						logging_error("On LinkRequest reply: local relay is unspecifed on link " << ldn );
						showLinkState();
					}
					ldn->remoteRelay  = linkReq->getRelay();
					ldn->remoteLinkId = linkReq->getRemoteLinkId();
					ldn->remoteNode   = overlayMsg->getSourceNode();

					ldn->markAlive();

					// compile and send update message
					OverlayMsg _overlayMsg( OverlayMsg::typeUpdate, ldn->service, nodeId );
					_overlayMsg.setAutoLink(ldn->autolink);
					sendMessage( &_overlayMsg, ldn );

					// auto links: link has been accepted -> send queued messages
					if( ldn->messageQueue.size() > 0 ) {
						logging_info( "Sending out queued messages on link " <<
							ldn->overlayId.toString() );
						BOOST_FOREACH( Message* msg, ldn->messageQueue ) {
							sendMessage( msg, ldn->overlayId );
							delete msg;
						}
						ldn->messageQueue.clear();
					}

					ldn->listener->onLinkUp( ldn->overlayId, ldn->remoteNode );

					// try to establish a direct link
					ldn->communicationId =
						bc->establishLink( *linkReq->getEndpoint(), i->second );
				}

				// no relay node-> use overlay routing
				else {
					ldn->up = true;

					// establish direct link
					ldn->communicationId =
							bc->establishLink( *linkReq->getEndpoint(), i->second );
				}
			} else {
				logging_debug( "Link request received from node id="
						<< overlayMsg->getSourceNode() );

				// create link descriptor
				LinkDescriptor* ldn =
					createLinkDescriptor(overlayMsg->getSourceNode(),
							overlayMsg->getService(), LinkID::UNSPECIFIED );
				assert(!ldn->overlayId.isUnspecified());

				// create reply message
				OverlayMsg overlay_msg( OverlayMsg::typeLinkRequest, service, nodeId );
				LinkRequest link_request_msg(
					linkReq->getNonce(),
					&bc->getEndpointDescriptor(),
					true, ldn->overlayId, ldn->localRelay
				);
				overlay_msg.encapsulate( &link_request_msg );

				// debug message
				logging_debug( "Sending LinkRequest reply for link with nonce " <<
						linkReq->getNonce() );

				// if this is a relay link-> update information & inform listeners
				if (!linkReq->getRelay().isUnspecified()) {
					// set flags
					ldn->up = true;
					ldn->relay = true;
					if (ldn->localRelay.isUnspecified()) {
						logging_error("On LinkRequest request: local relay is unspecifed on link " << ldn );
						showLinkState();
					}
					ldn->remoteRelay  = linkReq->getRelay();
					ldn->remoteNode   = overlayMsg->getSourceNode();
					ldn->remoteLinkId = linkReq->getRemoteLinkId();
					ldn->listener->onLinkUp( ldn->overlayId, ldn->remoteNode );
				}

				// route message back over overlay
				sendMessage( &overlay_msg, ldn );
			}
			return true;
		}

		// ---------------------------------------------------------------------
		// handle relay message to forward messages
		// ---------------------------------------------------------------------
		case OverlayMsg::typeRelay: {

			logging_debug( "received relay request on link" );

			// decapsulate message
			RelayMessage* relayMsg = overlayMsg->decapsulate<RelayMessage>();

			// is relay message informative?
			switch (relayMsg->getType()) {

				// handle relay notification
				case RelayMessage::typeInform: {
					logging_info("Received relay information message with"
							<< " relay " << relayMsg->getRelayNode()
							<< " destination " << relayMsg->getDestNode() );

					// mark incoming link as relay
					if (ld!=NULL) ld->markAsRelay();

					// am I the destination of this message? yes->
					if (relayMsg->getDestNode() == nodeId ) {
						// deliver relay message locally!
						logging_debug("Relay message reached destination. Handling the message.");
						handleMessage( relayMsg, relayMsg->getDestLink(), LinkID::UNSPECIFIED, remoteNode );
						return true;
					}

					// create route message
					OverlayMsg _overMsg( *overlayMsg );
					RelayMessage _relayMsg( *relayMsg );
					_relayMsg.setType( RelayMessage::typeRoute );
					_overMsg.encapsulate( &_relayMsg );

					// forward message
					if (relayMsg->getRelayNode() == nodeId || relayMsg->getRelayNode().isUnspecified()) {
						logging_info("Routing relay message to " << relayMsg->getDestNode().toString() );
						overlayInterface->routeMessage(relayMsg->getDestNode(), &_overMsg );
					} else {
						logging_info("Routing relay message to " << relayMsg->getRelayNode().toString() );
						overlayInterface->routeMessage(relayMsg->getRelayNode(), &_overMsg );
					}
					return true;
				}

				// handle relay routing
				case RelayMessage::typeRoute: {
					logging_info("Received relay route message with"
							<< " relay " << relayMsg->getRelayNode()
							<< " destination " << relayMsg->getDestNode() );

					// mark incoming link as relay
					if (ld!=NULL) ld->markAsRelay();

					// am I the destination of this message? yes->
					if (relayMsg->getDestNode() == nodeId ) {
						// deliver relay message locally!
						logging_debug("Relay message reached destination. Handling the message.");
						handleMessage( relayMsg, relayMsg->getDestLink(), LinkID::UNSPECIFIED, remoteNode );
						return true;
					}

					// am I the relay for this message? yes->
					if (relayMsg->getRelayNode() == nodeId ) {
						logging_debug("I'm the relay for this message. Sending to destination.");
						OverlayMsg _overMsg( *overlayMsg );
						RelayMessage _relayMsg( *relayMsg );
						_overMsg.encapsulate(&_relayMsg);

						/// this must be handled by using relay link!
						overlayInterface->routeMessage(relayMsg->getDestNode(), &_overMsg );
						return true;
					}

					// error: I'm not a relay or destination!
					logging_error("This node is neither relay nor destination. Dropping Message!");
					return true;
				}
				default: {
					logging_error("RelayMessage Unknown!");
					return true;
				}
			}

			break;
		}

		// ---------------------------------------------------------------------
		// handle keep-alive messages
		// ---------------------------------------------------------------------
		case OverlayMsg::typeKeepAlive: {

			logging_debug( "received keep-alive on link" );

			if ( ld != NULL ) {
				//logging_force("Keep-Alive for "<< ld->overlayId);
				ld->markAlive();
			}
			break;
		}

		// ---------------------------------------------------------------------
		// handle direct link replacement messages
		// ---------------------------------------------------------------------
		case OverlayMsg::typeDirectLink: {

			logging_debug( "received direct link replacement request" );

			LinkDescriptor* rld = getDescriptor( overlayMsg->getRelayLink() );
			logging_force( "Received direct link convert notification for " << rld );

			// set communcation link id and set it up
			rld->communicationId = ld->communicationId;

			// this is neccessary since this link was a relay link before!
			rld->communicationUp = true;

			// this is not a relay link anymore!
			rld->relay = false;
			rld->localRelay  = NodeID::UNSPECIFIED;
			rld->remoteRelay = NodeID::UNSPECIFIED;

			// mark used and alive!
			rld->markAsUsed();
			rld->markAlive();

			// erase the original descriptor
			eraseDescriptor(ld->overlayId);
			break;
		}

		// ---------------------------------------------------------------------
		// handle unknown message type
		// ---------------------------------------------------------------------
		default: {
			logging_error( "received message in invalid state! don't know " <<
					"what to do with this message of type " <<
					overlayMsg->getType() );
			return false;
		}

	} /* switch */

	return false;
}

// ----------------------------------------------------------------------------

void BaseOverlay::broadcastMessage(Message* message, const ServiceID& service) {

	logging_debug( "broadcasting message to all known nodes " <<
			"in the overlay from service " + service.toString() );

	OverlayInterface::NodeList nodes = overlayInterface->getKnownNodes();
	OverlayInterface::NodeList::iterator i = nodes.begin();
	for(; i != nodes.end(); i++ ) {
		if( *i == nodeId) continue; // don't send to ourselfs
		sendMessage( message, *i, service );
	}
}

vector<NodeID> BaseOverlay::getOverlayNeighbors(bool deep) const {
	// the known nodes _can_ also include our node, so we remove ourself
	vector<NodeID> nodes = overlayInterface->getKnownNodes(deep);
	vector<NodeID>::iterator i = find( nodes.begin(), nodes.end(), this->nodeId );
	if( i != nodes.end() ) nodes.erase( i );
	return nodes;
}

const NodeID& BaseOverlay::getNodeID(const LinkID& lid) const {
	if( lid == LinkID::UNSPECIFIED ) return nodeId;
	const LinkDescriptor* ld = getDescriptor(lid);
	if( ld == NULL ) return NodeID::UNSPECIFIED;
	else return ld->remoteNode;
}

vector<LinkID> BaseOverlay::getLinkIDs( const NodeID& nid ) const {
	vector<LinkID> linkvector;
	BOOST_FOREACH( LinkDescriptor* ld, links ) {
		if( ld->remoteNode == nid || nid == NodeID::UNSPECIFIED ) {
			linkvector.push_back( ld->overlayId );
		}
	}
	return linkvector;
}


void BaseOverlay::onNodeJoin(const NodeID& node) {
	JoiningNodes::iterator i = std::find( joiningNodes.begin(), joiningNodes.end(), node );
	if( i == joiningNodes.end() ) return;

	logging_info( "node has successfully joined baseoverlay and overlay structure "
			<< node.toString() );

	joiningNodes.erase( i );
}

void BaseOverlay::eventFunction() {

	// send keep-alive messages over established links
	BOOST_FOREACH( LinkDescriptor* ld, links ) {
		if (!ld->up) continue;
		OverlayMsg overMsg( OverlayMsg::typeKeepAlive,
			OverlayInterface::OVERLAY_SERVICE_ID, nodeId );
		sendMessage( &overMsg, ld );
	}

	// iterate over all links and check for time boundaries
	vector<LinkDescriptor*> oldlinks;
	time_t now = time(NULL);
	BOOST_FOREACH( LinkDescriptor* ld, links ) {
		// remote used as relay flag
		if ( ld->usedAsRelay && difftime( now, ld->timeUsedAsRelay ) > 10)
			ld->usedAsRelay = false;

		// keep alives missed? yes->
		if ( !ld->up && difftime( now, ld->keepAliveTime ) > 2 ) {

			// increase counter
			ld->keepAliveMissed++;

			// missed more than four keep-alive messages (4 sec)? -> drop link
			if (ld->keepAliveMissed > 10) {
				logging_force( "Link connection request is stale, closing: " << ld );
				oldlinks.push_back( ld );
			}
		}

		if (!ld->up) continue;

		// drop links that are dropped and not used as relay
		if (ld->dropWhenRelaysLeft && !ld->usedAsRelay && !ld->autolink)
			oldlinks.push_back( ld );
		else

		// auto-link time exceeded?
		if ( ld->autolink && difftime( now, ld->lastuse ) > 30 )
			oldlinks.push_back( ld );

		else

		// keep alives missed? yes->
		if ( !ld->autolink && difftime( now, ld->keepAliveTime ) > 2 ) {

			// increase counter
			ld->keepAliveMissed++;

			// missed more than four keep-alive messages (4 sec)? -> drop link
			if (ld->keepAliveMissed >= 8) {
				logging_force( "Link is stale, closing: " << ld );
				oldlinks.push_back( ld );
			}
		}
	}

	// show link state
	counter++;
	if (counter>=4) showLinkState();
	if (counter>=4 || counter<0) counter = 0;

	// drop links
	BOOST_FOREACH( const LinkDescriptor* ld, oldlinks ) {

		vector<LinkID>::iterator it = std::find(
				bootstrapLinks.begin(), bootstrapLinks.end(), ld->communicationId);

		if (!ld->communicationId.isUnspecified() && it != bootstrapLinks.end() ){
			logging_force( "Not dropping initiator link: " << ld );
			continue;
		}
		logging_force( "Link timed out. Dropping " << ld );
		dropLink( ld->overlayId );
	}
}

void BaseOverlay::showLinkState() {
	int i=0;
	logging_force("--- link state -------------------------------");
	BOOST_FOREACH( LinkDescriptor* ld, links ) {
		logging_force("link " << i << ": " << ld);
		i++;
	}
	logging_force("----------------------------------------------");
}

}} // namespace ariba, overlay