source: source/ariba/overlay/BaseOverlay.cpp@ 3071

// [Licence]
// The Ariba-Underlay Copyright
//
// Copyright (c) 2008-2009, Institute of Telematics, UniversitÀt Karlsruhe (TH)
//
// Institute of Telematics
// UniversitÀt 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.
// [Licence]

#include "BaseOverlay.h"

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

namespace ariba {
namespace overlay {

use_logging_cpp(BaseOverlay);

BaseOverlay::BaseOverlay()
        : bc(NULL), overlayInterface(NULL),
                nodeId(NodeID::UNSPECIFIED), spovnetId(SpoVNetID::UNSPECIFIED),
                initiatorLink(LinkID::UNSPECIFIED), state(BaseOverlayStateInvalid){
}

BaseOverlay::~BaseOverlay(){
}

void BaseOverlay::start( BaseCommunication& _basecomm, const NodeID& _nodeid ){

        bc = &_basecomm;
        nodeId = _nodeid;

        logging_info("creating base overlay");

        bc->registerMessageReceiver( this );
        bc->registerEventListener( this );

        ovl.visCreate( ovlId, nodeId, string(""), string("") );
        ovl.visChangeNodeColor(ovlId, nodeId, OvlVis::NODE_COLORS_GREY);

//      if (Identifier(Configuration::instance().read<unsigned long>("BASE_nodeid")) ==
//          Identifier(Configuration::instance().read<unsigned long>("SOURCE"))) {
//              ovl.visChangeNodeIcon(ovlId, nodeId, OvlVis::ICON_ID_CAMERA);
//      } else if (Identifier(Configuration::instance().read<unsigned long>("BASE_nodeid")) ==
//          Identifier(Configuration::instance().read<unsigned long>("MR_A"))) {
//              ovl.visChangeNodeIcon(ovlId, nodeId, OvlVis::ICON_ID_CHARACTER_A);
//      } else if (Identifier(Configuration::instance().read<unsigned long>("BASE_nodeid")) ==
//          Identifier(Configuration::instance().read<unsigned long>("MR_W"))) {
//              ovl.visChangeNodeIcon(ovlId, nodeId, OvlVis::ICON_ID_CHARACTER_W);
//      }

        // timer for auto link management
        Timer::setInterval( 5000 );
        Timer::start();
}

void BaseOverlay::stop() {

        logging_info("deleting base overlay");

        Timer::stop();
        bc->unregisterMessageReceiver( this );
        bc->unregisterEventListener( this );
}

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

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

        //
        // contact the spovnet initiator and request
        // to join. if the join is granted we will
        // receive further information on the structure
        // of the overlay that is used in the spovnet
        //
        // but first, we have to establish a link to the initiator...
        //

        spovnetId = id;
        state = BaseOverlayStateJoinInitiated;

        initiatorLink = bc->establishLink( bootstrapEp );
        logging_info("join process initiated for " << id.toString() << "...");
}

void BaseOverlay::leaveSpoVNet(){

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

        logging_debug( "dropping all auto-links ..." );

        // now we start leaving the spovnet: fist delete all links
        // that we still have in the baseoverlay initiated by
        // some services, the leave the actual overlay structure,
        // then leave the spovnet

        // --> drop all service links

        vector<LinkID> servicelinks;
        BOOST_FOREACH( LinkPair item, linkMapping ){
                if( item.second.service != OverlayInterface::OVERLAY_SERVICE_ID )
                        servicelinks.push_back( item.first );
        }
        BOOST_FOREACH( LinkID lnk, servicelinks ){
                // the dropLink function will remove
                // the item from the linkMapping
                dropLink( lnk );
        }

        // --> leave overlay structure

        logging_debug( "leaving overlay" );
        // first, leave the overlay interface
        if( overlayInterface != NULL )
                overlayInterface->leaveOverlay();

        // --> leave spovnet

        if( state != BaseOverlayStateInitiator ){

                // then, leave the spovnet baseoverlay
                OverlayMsg overMsg( OverlayMsg::OverlayMessageTypeBye, nodeId );
                bc->sendMessage( initiatorLink, &overMsg );

                // drop the link and set to correct state
                bc->dropLink( initiatorLink );
                initiatorLink = LinkID::UNSPECIFIED;
        }

        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;
        state = BaseOverlayStateInitiator;

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

        //
        // bootstrap against ourselfs
        //

        overlayInterface->joinOverlay();
        BOOST_FOREACH( NodeListener* i, nodeListeners ){
                i->onJoinCompleted( spovnetId );
        }

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

const LinkID BaseOverlay::establishLink(const NodeID& node, const ServiceID& service){

        // TODO: if this is not a onehop overlay the operation will go asynchronously
        const EndpointDescriptor& endpoint = overlayInterface->resolveNode( node );
        if( endpoint == EndpointDescriptor::UNSPECIFIED ){
                logging_error( "could not resolve node to endpoint. unable to establish link" );
                return LinkID::UNSPECIFIED;
        }

        logging_debug( "baseoverlay called to establish link between node " <<
                        node.toString() << " on endpoint " << endpoint.toString() <<
                        " for service " << service.toString() );

        return establishLink( endpoint, service );
}

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

        if( !communicationListeners.contains( service ) ){
                logging_error( "no registered listener on serviceid " << service.toString() );
                return LinkID::UNSPECIFIED;
        }

        const LinkID link = bc->establishLink( ep );

        CommunicationListener* receiver = communicationListeners.get( service );
        LinkItem item (link, NodeID::UNSPECIFIED, service, receiver);
        linkMapping.insert( make_pair(link, item) );

        return link;
}

void BaseOverlay::dropLink(const LinkID& link){

        logging_debug( "baseoverlay dropping link " << link.toString() );
        LinkMapping::iterator i = linkMapping.find( link );

        if( i == linkMapping.end() ){
                logging_warn( "can't drop link, mapping unknown " << link.toString() );
                return;
        }

        linkMapping.erase( i );

        LinkItem item = i->second;
        bc->dropLink( link );

        if( item.interface != NULL )
                item.interface->onLinkDown( link, item.node );
}

seqnum_t BaseOverlay::sendMessage(const Message* message, const LinkID& link ){

        logging_debug( "baseoverlay is sending message on link " << link.toString() );

        LinkMapping::iterator i = linkMapping.find( link );
        if( i == linkMapping.end() ){
                logging_error( "could not send message. link not found " << link.toString() );
                return -1;
        }

        OverlayMsg overmsg( OverlayMsg::OverlayMessageTypeData, i->second.service, nodeId );
        overmsg.encapsulate( const_cast<Message*>(message) );

        i->second.markused();
        return bc->sendMessage( link, &overmsg );
}

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

        LinkID link = LinkID::UNSPECIFIED;

        LinkMapping::iterator i = linkMapping.begin();
        LinkMapping::iterator iend = linkMapping.end();

        for( ; i != iend; i++ ){
                if( i->second.node == node && i->second.service == service ){
                        link = i->second.link;
                        break;
                }
        }

        if( link == LinkID::UNSPECIFIED ){

                logging_info( "no link could be found to send message to node " <<
                                node.toString() << " for service " << service.toString() <<
                                ". creating auto link ...");

                link = establishLink( node, service );
                LinkMapping::iterator i = linkMapping.find( link );

                if( i == linkMapping.end() || link == LinkID::UNSPECIFIED ){
                        logging_error( "failed to establish auto link to node " << node.toString() <<
                                        " for service " << service.toString() );
                        return -1;
                }

                i->second.autolink = true;

                logging_debug( "establishing autolink in progress to node "
                                << node.toString() << " with new link-id " << link.toString() );

        } // if( link != LinkID::UNSPECIFIED )

        assert( link != LinkID::UNSPECIFIED );

        // mark the link as used, as we
        // now send a message through it
        i->second.markused();

        // send the message through the new link. the link may not be functional,
        // but for us there is a link-id so we can send messages through it. if
        // the link is not yet up and the message needs to be cached, this is the
        // task of the BaseCommunication, it will cache and send it later.
        return sendMessage( message, link );
}

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

        return bc->getEndpointDescriptor( link );
}

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

        if( node == nodeId || node == NodeID::UNSPECIFIED )
                return bc->getEndpointDescriptor();

        if( overlayInterface == NULL ){
                logging_error( "overlay interface not set, cannot resolve endpoint" );
                return EndpointDescriptor::UNSPECIFIED;
        }

        // TODO: if this is not a onehop overlay the operation will go asynchronously
        return overlayInterface->resolveNode( node );
}

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 );

        NodeListenerVector::iterator i = find( nodeListeners.begin(), nodeListeners.end(), listener );
        if( i != nodeListeners.end() ){
                logging_warn( "node listener " << listener << " is already bound, cannot bind" );
                return false;
        }

        nodeListeners.push_back( listener );
        return true;
}

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

        NodeListenerVector::iterator i = find( nodeListeners.begin(), nodeListeners.end(), listener );
        if( i == nodeListeners.end() ){
                logging_warn( "node listener " << listener << " is not bound, cannot unbind" );
                return false;
        }

        nodeListeners.erase( i );
        return true;
}

void BaseOverlay::onLinkUp(const LinkID& id, const NetworkLocator* local, const NetworkLocator* remote){

        logging_debug( "base overlay received linkup event " + id.toString() );
        // TODO: updateOvlVis( getNodeID(id) );

        //
        // if we get up a link while we are in the
        // join phase and this is the link that
        // we have initiated towards the spovnet owner
        // continue the join process by sending
        // a join request message through the link
        //

        if( state == BaseOverlayStateJoinInitiated && id == initiatorLink){

                logging_info( "join has been initiated by me and the link is now up. " <<
                                "sending out join request for spovnet " <<
                                spovnetId.toString() );

                OverlayMsg overMsg( OverlayMsg::OverlayMessageTypeJoinRequest, nodeId );
                JoinRequest joinmsg( spovnetId, nodeId );
                overMsg.encapsulate( &joinmsg );

                state = BaseOverlayStateJoinInitiated; // state remains in JoinInitiated
                bc->sendMessage( id, &overMsg );

                return;

        } // if( state == BaseOverlayStateJoinInitiated && id == initiatorLink)

        //
        // otherwise this is a link initiated by a service
        // then we exchange update messages to exchange the
        // service id and node id for the link. in this case
        // we should have a link mapping for this link. if
        // we have no link mapping this link was initiated by
        // the remote side.
        //

        LinkMapping::iterator i = linkMapping.find( id );

        if( i == linkMapping.end() ){

                LinkItem item (id, NodeID::UNSPECIFIED, ServiceID::UNSPECIFIED, NULL );
                linkMapping.insert( make_pair(id, item) );

        } else {

                logging_debug( "sending out OverlayMessageTypeUpdate" <<
                                " for service " << i->second.service.toString() <<
                                " with local node id " << nodeId.toString() <<
                                " on link " << id.toString() );

                OverlayMsg overMsg(
                        OverlayMsg::OverlayMessageTypeUpdate,
                        i->second.service,
                        nodeId
                        );

                bc->sendMessage( id, &overMsg );
                i->second.markused();

        } // if( i == linkMapping.end() )

        // the link is only valid for the service when we receive
        // the OverlayMessageTypeUpdate from the remote node and
        // have the nodeid and serviceid for the link!
}

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

        logging_debug( "link went down " << id.toString() );

        //
        // tell the service that the link went
        // down and remove the mapping
        //

        LinkMapping::iterator i = linkMapping.find( id );
        if( i == linkMapping.end() ) {
                // this can also be one of the baseoverlay links that
                // no mapping is stored for. therefore we issue no warning.
                // it can also be a link that has been dropped and the
                // mapping is already deleted in the dropLink function.
                // also, the service notification is issued then in dropLink
                return;
        }

        if( i->second.interface != NULL )
                i->second.interface->onLinkDown( id, i->second.node );

        linkMapping.erase( i );
}

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

        logging_debug( "link changed " << id.toString() );

        //
        // tell the service that the link changed
        //

        LinkMapping::iterator i = linkMapping.find( id );
        if( i == linkMapping.end() ) return;

        if( i->second.interface != NULL ){
                i->second.interface->onLinkChanged( id, i->second.node );
                // call onLinkQoSChanged?
        }

        i->second.markused();
}

void BaseOverlay::onLinkFail(const LinkID& id, const NetworkLocator* local, const NetworkLocator* remote){

        logging_debug( "link failed " << id.toString() );

        //
        // tell the service that the link failed
        //

        LinkMapping::iterator i = linkMapping.find( id );
        if( i == linkMapping.end() ) return;

        if( i->second.interface != NULL )
                i->second.interface->onLinkFail( id, i->second.node );

        i->second.markused();
}

void BaseOverlay::onLinkQoSChanged(const LinkID& id, const NetworkLocator* local, const NetworkLocator* remote, const QoSParameterSet& qos) {

        logging_debug( "link qos changed " << id.toString() );

        //
        // tell the service that the link qos has changed
        //

        LinkMapping::iterator i = linkMapping.find( id );
        if( i == linkMapping.end() ) return;

        // TODO: convert QoSParameterSet to the LinkProperties properties
        if( i->second.interface != NULL ){
                // TODO: currently not in the interface: i->second.interface->onLinkQoSChanged( id, i->second.node, LinkProperties::DEFAULT );
        }

        i->second.markused();
}

bool BaseOverlay::onLinkRequest( const LinkID& id, const NetworkLocator* local, const NetworkLocator* remote ){

        // also see in the receiveMessage function. there the higher layer service
        // is asked whether to accept link requests, but there a basic link association is
        // already built up, so we know the node id
        logging_debug("received link request from " << remote->toString() << ", accepting");
        return true;
}

bool BaseOverlay::receiveMessage(const Message* message,
        const LinkID& link, const NodeID& /*the nodeid is invalid in this case! removed var to prevent errors*/ ){

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

        // mark the link as in action
        LinkMapping::iterator item = linkMapping.find( link );
        if( item != linkMapping.end() ) item->second.markused();

        //
        // handle user date that we forward to the
        // appropriate service using the service id
        // in the message. as we don't know the class
        // of message that the service handles, we
        // forward it as a pure Message*
        //

        if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeData) ) {

                logging_debug( "baseoverlay received message of type OverlayMessageTypeData" );

                const ServiceID& service = overlayMsg->getService();
                CommunicationListener* serviceListener = communicationListeners.get( service );

                logging_debug( "received data for service " << service.toString() );

                if( serviceListener != NULL )
                        serviceListener->onMessage( overlayMsg, overlayMsg->getSourceNode(), link );

                return true;

        } // if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeData) )

        //
        // handle spovnet instance join requests
        //

        else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeJoinRequest) &&
                                                state == BaseOverlayStateInitiator){

                logging_debug( "baseoverlay received message of type OverlayMessageTypeJoinRequest" );

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

                //
                // make sure that the node actually wants to join
                // the correct spovnet id that we administrate
                //

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

                //
                // only if all services allow the node to join it is allowed
                // using the isJoinAllowed interface security policies can be
                // implemented by higher layer services
                //

                // TODO: here you can implement mechanisms to deny joining of a node
                bool allow = true;

                logging_info( "sending back join reply for spovnet " <<
                                spovnetId.toString() << " to node " <<
                                overlayMsg->getSourceNode().toString() <<
                                ". result: " << (allow ? "allowed" : "denied") );

                joiningNodes.push_back( overlayMsg->getSourceNode() );

                //
                // send back our spovnetid, default overlay parameters,
                // join allow result, and ourself as the endpoint
                // to bootstrap the overlay against
                //

                OverlayMsg retmsg( OverlayMsg::OverlayMessageTypeJoinReply, nodeId );
                JoinReply replyMsg( spovnetId, OverlayParameterSet::DEFAULT,
                                        allow, getEndpointDescriptor() );

                retmsg.encapsulate(&replyMsg);
                bc->sendMessage( link, &retmsg );

                return true;

        } // else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeJoinRequest) && state == BaseOverlayStateInitiator)

        //
        // handle replies to spovnet instance join requests
        //

        else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeJoinReply) &&
                                                state == BaseOverlayStateJoinInitiated){

                logging_debug( "baseoverlay received message of type OverlayMessageTypeJoinReply" );

                JoinReply* replyMsg = overlayMsg->decapsulate<JoinReply>();
                logging_info( "received spovnet join reply" );

                //
                // make sure that we actually wanted to get
                // into the spovnet whose id is in the message
                //

                if( replyMsg->getSpoVNetID() != spovnetId ){
                        logging_error( "received spovnet join reply for spovnet " <<
                                        replyMsg->getSpoVNetID().toString() <<
                                        " but we wanted to join spovnet " <<
                                        spovnetId.toString() );

                        // state does not change here, maybe
                        // the reply does come in later
                        return false;
                }

                //
                // if we did not get access to the spovnet
                // notify of the failure and
                // close the link to the initiator
                //

                if( ! replyMsg->getJoinAllowed() ){

                        logging_error( "our join request has been denied" );

                        bc->dropLink( initiatorLink );
                        initiatorLink = LinkID::UNSPECIFIED;
                        state = BaseOverlayStateInvalid;

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

                        return true;
                }

                logging_info( "join request has been accepted for spovnet " << spovnetId.toString() );

                //
                // if we did get access to the spovnet
                // we try to create the overlay structure
                // as given in the reply message
                //

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

                if( overlayInterface == NULL ){
                        logging_error( "overlay structure not supported" );

                        bc->dropLink( initiatorLink );
                        initiatorLink = LinkID::UNSPECIFIED;
                        state = BaseOverlayStateInvalid;

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

                        return true;
                }

                //
                // now start the join process for the overlay.
                // the join process for the spovnet baseoverlay
                // is now complete. we use the endpoint for
                // overlay structure bootstrapping that the
                // initiator provided in his reply message
                //

                state = BaseOverlayStateCompleted;
                ovl.visChangeNodeColor( ovlId, nodeId, OvlVis::NODE_COLORS_GREEN);

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

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

                return true;

        } // else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeJoinReply) && state == BaseOverlayStateJoinInitiated)


        //
        // handle update messages for link establishment
        //

        else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeUpdate) ){

                logging_debug( "baseoverlay received message of type OverlayMessageTypeUpdate" );

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

                //
                // we should have a linkmapping for the link, otherwise
                // we ignore update messages
                //

                LinkMapping::iterator i = linkMapping.find( link );
                if( i == linkMapping.end() ){
                        logging_warn( "received overlay update message for link " <<
                                        link.toString() << " for which we have no mapping" );
                        return false;
                }

                //
                // update our link mapping information for this link
                //

                bool changed = ( i->second.node != sourcenode ) || ( i->second.service != service );

                i->second.node = sourcenode;
                i->second.service = service;

                //
                // if our link information changed, we send out an update, too
                //

                if( changed ){
                        OverlayMsg overMsg( OverlayMsg::OverlayMessageTypeUpdate, i->second.service, nodeId );
                        bc->sendMessage( link, &overMsg );
                }

                //
                // set the correct listener service for the linkitem
                // now we can tell the registered service of the linkup event
                //

                if( !communicationListeners.contains( service ) ){
                        logging_warn( "linkup event for service that has not been registered" );
                        return false;
                }

                CommunicationListener* iface = communicationListeners.get( service );
                if( iface == NULL ){
                        logging_warn( "linkup event for service that has been registered with a NULL interface" );
                        return true;
                }

                i->second.interface = iface;
                i->second.markused();

                //
                // ask the service whether it wants to accept this link
                //

                if( iface->onLinkRequest(sourcenode) ){
                        iface->onLinkUp( link, sourcenode );
                } else {
                        // prevent onLinkDown calls to the service
                        i->second.interface = NULL;
                        // drop the link
                        dropLink( link );
                }

                return true;

        } // else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeUpdate) )

        //
        // bye messages to say goodbye
        //

        else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeBye)){

                logging_debug( "baseoverlay received message of type OverlayMessageTypeBye" );

                logging_debug( "received bye message from " <<
                                overlayMsg->getSourceNode().toString() );

                //
                // if we are the initiator and receive a bye from a node
                // the node just left. if we are a node and receive a bye
                // from the initiator, we have to close, too.
                //

                if( overlayMsg->getSourceNode() == spovnetInitiator ){

                        bc->dropLink( initiatorLink );
                        initiatorLink = LinkID::UNSPECIFIED;
                        state = BaseOverlayStateInvalid;

                        logging_fatal( "initiator ended spovnet" );

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

                } else {

                        // a node that said goodbye and we are the initiator
                        // don't have to do much here, as the node also
                        // will go out of the overlay structure
                        logging_info( "node left " << overlayMsg->getSourceNode() );

                }

                return true;

        } // else if( overlayMsg->isType(OverlayMsg::OverlayMessageTypeBye))

        //
        // something wrong ...
        //

        else {

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

        } // else

        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();
        OverlayInterface::NodeList::iterator iend = nodes.end();

        for( ; i != iend; i++ ){
                if( *i == nodeId) continue; // don't send to ourselfs
                sendMessage( message, *i, service );
        }
}

vector<NodeID> BaseOverlay::getOverlayNeighbors() const {
        // the known nodes _can_ also include our
        // node, so we remove ourselfs

        vector<NodeID> nodes = overlayInterface->getKnownNodes();
        vector<NodeID>::iterator i = find( nodes.begin(), nodes.end(), this->nodeId );
        if( i != nodes.end() ) nodes.erase( i );

        return nodes;
}

void BaseOverlay::updateOvlVis( const NodeID& n ) {
        NodeID node = n;
/*      void visShowNodeBubble (
        NETWORK_ID network,
        NodeID& node,
        string label
        );
*/
        using namespace std;

        if (node == nodeId || node.isUnspecified()) return;

        // min/max
        if ( node < min || min.isUnspecified() ) min = node;
        if ( node > max || max.isUnspecified() ) max = node;

        // successor
        if ( succ.isUnspecified() || (node > nodeId && (succ < nodeId || (node-nodeId) < (succ-nodeId))) ) {
                if (!succ.isUnspecified() && node != succ)
                        ovl.visDisconnect(ovlId, nodeId, succ, string(""));
                succ = node;
                ovl.visConnect(ovlId, nodeId, succ, string(""));
        }

        // set successor (circle-wrap)
        if (succ.isUnspecified() && !min.isUnspecified()) {
                succ = min;
                ovl.visConnect(ovlId, nodeId, succ, string(""));
        }
}

const NodeID& BaseOverlay::getNodeID(const LinkID& lid) const {

        if( lid == LinkID::UNSPECIFIED ) return nodeId;

        LinkMapping::const_iterator i = linkMapping.find( lid );
        if( i == linkMapping.end() ) return NodeID::UNSPECIFIED;
        else return i->second.node;
}

void BaseOverlay::incomingRouteMessage(Message* msg){
        // gets handled as normal data message
        receiveMessage( msg, LinkID::UNSPECIFIED, NodeID::UNSPECIFIED );
}

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(){

        list<LinkID> oldlinks;
        time_t now = time(NULL);

        // first gather all the links from linkMapping that need droppin
        // don't directly drop, as the dropLink function affects the
        // linkMapping structure that we are traversing here.
        // drop links after a timeout of 30s

        BOOST_FOREACH( LinkPair item, linkMapping ){
                if( item.second.autolink && difftime(now, item.second.lastuse) > 30)
                        oldlinks.push_back( item.first );
        }

        BOOST_FOREACH( const LinkID lnk, oldlinks ){
                logging_debug( "auto-link " << lnk.toString() << " timed out and is getting dropped" );
                dropLink( lnk );
        }
}

}} // namespace ariba, overlay