Changeset 5870 for source/ariba/overlay/BaseOverlay.cpp

Timestamp:

Aug 11, 2009, 4:11:02 PM (15 years ago)

Author:

Christoph Mayer

Message:

merge noch nicht fertig

File:

• source/ariba/overlay/BaseOverlay.cpp (modified) (32 diffs)

source/ariba/overlay/BaseOverlay.cpp

@@ -49 +49 @@
 
 #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"
@@ -59 +58 @@
 namespace ariba {
 namespace overlay {
+
+/* *****************************************************************************
+ * PREREQUESITES
+ * ****************************************************************************/
+
+CommunicationListener* BaseOverlay::getListener( const ServiceID& service ) {
+        if( !communicationListeners.contains( service ) ) {
+                logging_error( "No listener found for service " << service.toString() );
+                return NULL;
+        }
+        CommunicationListener* listener = communicationListeners.get( service );
+        assert( listener != NULL );
+        return listener;
+}
+
+// link descriptor handling ----------------------------------------------------
 
 LinkDescriptor* BaseOverlay::getDescriptor( const LinkID& link, bool communication ) {
@@ -91 +106 @@
         if ( desc == NULL ) {
                 desc = new LinkDescriptor();
-                desc->overlayId = link;
+                if (!link.isUnspecified()) desc->overlayId = link;
                 links.push_back(desc);
         }
@@ -99 +114 @@
 /// returns a auto-link descriptor
 LinkDescriptor* BaseOverlay::getAutoDescriptor( const NodeID& node, const ServiceID& service ) {
+        // search for a descriptor that is already up
         BOOST_FOREACH( LinkDescriptor* lp, links )
                 if (lp->autolink && lp->remoteNode == node && lp->service == service && lp->up)
                         return lp;
+        // if not found, search for one that is about to come up...
         BOOST_FOREACH( LinkDescriptor* lp, links )
                 if (lp->autolink && lp->remoteNode == node && lp->service == service )
@@ -108 +125 @@
 }
 
-/// returns a direct local link relay descriptor for the given remote node
-LinkDescriptor* BaseOverlay::getRelayDescriptor( const NodeID& id ) {
-
+/// stabilizes link information
+void BaseOverlay::stabilizeLinks() {
+        // send keep-alive messages over established links
+        BOOST_FOREACH( LinkDescriptor* ld, links ) {
+                if (!ld->up) continue;
+                OverlayMsg msg( OverlayMsg::typeLinkAlive,
+                        OverlayInterface::OVERLAY_SERVICE_ID, nodeId, ld->remoteNode );
+                msg.setRelayed(true);
+                if (ld->relayed) msg.setRouteRecord(true);
+                send_link( &msg, ld->overlayId );
+        }
+
+<<<<<<< .working
         // get used next hop towards node
         LinkDescriptor* rld = NULL;
@@ -118 +145 @@
                 // get descriptor of first hop
                 rld = getDescriptor(rlid);
-
+=======
+        // 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->relaying && difftime( now, ld->timeRelaying ) > 10)
+                        ld->relaying = false;
+>>>>>>> .merge-rechts.r5869
+
+<<<<<<< .working
                 // is first hop a relay path use local relay
                 if ( rld->relay ) relayNode = rld->localRelay;
@@ -125 +162 @@
                 else relayNode = rld->remoteNode;
         }
-
-        // if first relay is unknown choose a arbitrary direct node as relay
-        if ( relayNode.isUnspecified() ) {
-                for (size_t i=0; i<links.size(); i++)
-                        if (links[i]->up &&
-                                links[i]->communicationUp &&
-                                !links[i]->relay &&
-                                links[i]->keepAliveMissed <= 1 &&
-                                links[i]->service == OverlayInterface::OVERLAY_SERVICE_ID) {
-                                relayNode = links[i]->remoteNode;
-                                break;
+=======
+                // keep alives and not up? yes-> link connection request is stale!
+                if ( !ld->up && difftime( now, ld->keepAliveTime ) >= 2 ) {
+>>>>>>> .merge-rechts.r5869
+
+                        // increase counter
+                        ld->keepAliveMissed++;
+
+                        // missed more than four keep-alive messages (10 sec)? -> drop link
+                        if (ld->keepAliveMissed > 4) {
+                                logging_info( "Link connection request is stale, closing: " << ld );
+                                ld->relaying = false;
+                                oldlinks.push_back( ld );
+                                continue;
                         }
-        }
-
-        // no local relay found-> damn!
-        if (relayNode.isUnspecified()) return NULL;
-
+                }
+
+                if (!ld->up) continue;
+
+<<<<<<< .working
         // get descriptor
         BOOST_FOREACH( LinkDescriptor* lp, links )
@@ -149 +189 @@
                     lp->up)
                         return lp;
-
+=======
+                // drop links that are dropped and not used as relay
+                if (ld->dropAfterRelaying && !ld->relaying && !ld->autolink) {
+                        oldlinks.push_back( ld );
+                        continue;
+                }
+
+                // auto-link time exceeded?
+                if ( ld->autolink && difftime( now, ld->lastuse ) > 30 ) {
+                        oldlinks.push_back( ld );
+                        continue;
+>>>>>>> .merge-rechts.r5869
+
+                // keep alives missed? yes->
+                if ( difftime( now, ld->keepAliveTime ) > 2 ) {
+
+                        // increase counter
+                        ld->keepAliveMissed++;
+
+                        // missed more than four keep-alive messages (4 sec)? -> drop link
+                        if (ld->keepAliveMissed >= 4) {
+                                logging_info( "Link is stale, closing: " << ld );
+                                ld->relaying = false;
+                                oldlinks.push_back( ld );
+                                continue;
+                        }
+                }
+        }
+
+        // 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_info( "Not dropping initiator link: " << ld );
+                        continue;
+                }
+*/
+                logging_info( "Link timed out. Dropping " << ld );
+                dropLink( ld->overlayId );
+        }
+
+        // show link state
+        counter++;
+        if (counter>=4) showLinks();
+        if (counter>=4 || counter<0) counter = 0;
+}
+
+void BaseOverlay::showLinks() {
+        int i=0;
+        logging_info("--- link state -------------------------------");
+        BOOST_FOREACH( LinkDescriptor* ld, links ) {
+                logging_info("link " << i << ": " << ld);
+                i++;
+        }
+        logging_info("----------------------------------------------");
+}
+
+// internal message delivery ---------------------------------------------------
+
+/// routes a message to its destination node
+void BaseOverlay::route( OverlayMsg* message, LinkDescriptor* incomingLink ) {
+
+        // exceeded time-to-live? yes-> drop message
+        if (message->getNumHops() > message->getTimeToLive()) {
+                logging_warn("Message exceeded TTL -> drop message!");
+                return;
+
+        // no-> forward message
+        } else {
+                // destinastion myself? yes-> handle message
+                if (message->getDestinationNode() == nodeId)
+                        handleMessage( message, incomingLink );
+                else
+                        // no->send message to next hop
+                        send( message, message->getDestinationNode() );
+        }
+}
+
+/// sends a message to another node, delivers it to the base overlay class
+seqnum_t BaseOverlay::send( OverlayMsg* message, const NodeID& destination ) {
+        LinkDescriptor* next_link = NULL;
+
+        // drop messages to unspecified destinations
+        if (destination.isUnspecified()) return -1;
+
+        // send messages to myself -> handle message and drop warning!
+        if (destination == nodeId) {
+                logging_warn("Sent message to myself. Handling message.")
+                Message msg;
+                msg.encapsulate(message);
+                handleMessage( &msg, NULL );
+                return -1;
+        }
+
+        // relay path known? yes-> send over relay link
+        next_link = getRelayLinkTo( destination );
+        if (next_link != NULL) {
+                next_link->setRelaying();
+                return send(message, next_link);
+        }
+
+        // no-> relay path! route over overlay path
+        LinkID next_id = overlayInterface->getNextLinkId( destination );
+        if (next_id.isUnspecified()) {
+                logging_error("Could not send message. No next hop found to " << destination );
+                return -1;
+        }
+
+        // get link descriptor, up and running? yes-> send message
+        next_link = getDescriptor(next_id);
+        if (next_link != NULL && next_link->up)
+                return send(message, next_link);
+
+        // no-> error, dropping message
+        else {
+                logging_error("Could not send message. Link not known or up");
+                return -1;
+        }
+
+        // not reached-> fail
+        return -1;
+}
+
+/// send a message using a link descriptor, delivers it to the base overlay class
+seqnum_t BaseOverlay::send( OverlayMsg* message, LinkDescriptor* ld, bool ignore_down ) {
+        assert(ld!=NULL);
+
+        // check if up
+        if (!ld->up && !ignore_down) {
+                logging_error("Can not send message. Link not up:" << ld );
+                return -1;
+        }
+
+        // handle relayed link
+        if (ld->relayed) {
+                logging_debug("send(): Resolving direct link for relayed link to "
+                        << ld->remoteNode);
+                ld = getRelayLinkTo( ld->remoteNode );
+                if (ld==NULL) {
+                        logging_error("Direct link not found.");
+                        return -1;
+                }
+                message->setRelayed();
+                ld->setRelaying();
+        }
+
+        // handle direct link
+        if (ld->communicationUp) {
+                logging_debug("send(): Sending message over direct link.");
+                return bc->sendMessage( ld->communicationId, message );
+        } else {
+                logging_error("send(): Could not send mesage. "
+                                "Not a relayed link and direct link is not up.");
+                return -1;
+        }
+        return -1;
+}
+
+seqnum_t BaseOverlay::send_node( OverlayMsg* message, const NodeID& remote,
+        const ServiceID& service) {
+        message->setSourceNode(nodeId);
+        message->setService(service);
+        message->setDestinationNode(remote);
+        send( message, remote );
+}
+
+seqnum_t BaseOverlay::send_link( OverlayMsg* message, const LinkID& link,bool ignore_down ) {
+        LinkDescriptor* ld = getDescriptor(link);
+        if (ld==NULL) {
+                logging_error("Cannot find descriptor to link id=" << link.toString());
+                return -1;
+        }
+        message->setSourceNode(nodeId);
+        message->setSourceLink(ld->overlayId);
+        message->setService(ld->service);
+        message->setDestinationNode(ld->remoteNode);
+        message->setDestinationLink(ld->remoteLink);
+        return send( message, ld, ignore_down );
+}
+
+// relay route management ------------------------------------------------------
+
+/// stabilize relay information
+void BaseOverlay::stabilizeRelays() {
+        vector<relay_route>::iterator i = relay_routes.begin();
+        while (i!=relay_routes.end() ) {
+                relay_route& route = *i;
+                LinkDescriptor* ld = getDescriptor(route.link);
+                if (ld==NULL
+                        || !ld->up
+                        || difftime(route.used, time(NULL)) > 4) {
+                        logging_info("Forgetting relay information to node "
+                                        << route.node.toString() );
+                        i = relay_routes.erase(i);
+                } else
+                        i++;
+        }
+}
+
+void BaseOverlay::removeRelayLink( const LinkID& link ) {
+        vector<relay_route>::iterator i = relay_routes.begin();
+        while (i!=relay_routes.end() ) {
+                relay_route& route = *i;
+                if (route.link == link ) i = relay_routes.erase(i); else i++;
+        }
+}
+
+void BaseOverlay::removeRelayNode( const NodeID& remote ) {
+        vector<relay_route>::iterator i = relay_routes.begin();
+        while (i!=relay_routes.end() ) {
+                relay_route& route = *i;
+                if (route.node == remote ) i = relay_routes.erase(i); else i++;
+        }
+}
+
+/// refreshes relay information
+void BaseOverlay::refreshRelayInformation( const OverlayMsg* message, LinkDescriptor* ld ) {
+
+        // handle relayed messages from real links only
+        if (ld == NULL
+                || ld->relayed
+                || !message->isRelayed()
+                || message->getSourceNode()==nodeId ) return;
+
+        // check wheter this node is already part of the routing table
+        LinkID next_link = overlayInterface->getNextLinkId(message->getSourceNode());
+        if (next_link == ld->overlayId) return;
+        ld->setRelaying();
+
+        // try to find source node
+        BOOST_FOREACH( relay_route& route, relay_routes ) {
+
+                // relay route found? yes->
+                if ( route.node == message->getSourceNode() ) {
+
+                        // refresh timer
+                        route.used = time(NULL);
+
+                        // route has a shorter hop count? yes-> replace
+                        if (route.hops > message->getNumHops() ) {
+                                logging_info("Updating relay information to node "
+                                        << route.node.toString()
+                                        << " reducing to " << message->getNumHops() << " hops.");
+                                route.hops = message->getNumHops();
+                                route.link = ld->overlayId;
+                        }
+                        return;
+                }
+        }
+
+        // not found-> add new entry
+        relay_route route;
+        route.hops = message->getNumHops();
+        route.link = ld->overlayId;
+        route.node = message->getSourceNode();
+        route.used = time(NULL);
+        logging_info("Remembering relay information to node " << route.node.toString());
+        relay_routes.push_back(route);
+}
+
+/// returns a known "vital" relay link which is up and running
+LinkDescriptor* BaseOverlay::getRelayLinkTo( const NodeID& remote ) {
+        // try to find source node
+        BOOST_FOREACH( relay_route& route, relay_routes ) {
+                if (route.node == remote ) {
+                        LinkDescriptor* ld = getDescriptor( route.link );
+                        if (ld==NULL || !ld->up) return NULL; else return ld;
+                }
+        }
         return NULL;
 }
 
-/// returns the link descriptor that is actually used for sending a message over the overöay
-LinkDescriptor* BaseOverlay::getSendDescriptor( const NodeID& nodeid, bool follow ) {
-        for (size_t i=0; i<links.size(); i++)
-                if ( !links[i]->relay &&
-                        links[i]->up &&
-                        links[i]->communicationUp &&
-                        links[i]->keepAliveMissed <= 1 &&
-                        links[i]->remoteNode == nodeid &&
-                        links[i]->service == OverlayInterface::OVERLAY_SERVICE_ID) {
-                        return links[i];
-                }
-        LinkDescriptor* ld = getDescriptor(overlayInterface->getNextLinkId(nodeid));
-        if (ld != NULL && ld->relay && follow)
-                return getSendDescriptor(ld->localRelay, false);
-        return NULL;
-}
-
-NodeID BaseOverlay::getRelayNode( const NodeID& remoteNode ) {
-        LinkDescriptor* rld = getRelayDescriptor(remoteNode);
-        return rld!=NULL ? rld->remoteNode : NodeID::UNSPECIFIED;
-}
-
-/// routes a message over the overlay or directly sends it when a link is open
-seqnum_t BaseOverlay::sendOverlay( Message* message, const NodeID& nodeid, const NodeID& remoteRelay  ) {
-        /// send message directly to a neighbor
-        for (size_t i=0; i<links.size(); i++)
-                if ( !links[i]->relay &&
-                        links[i]->up &&
-                        links[i]->communicationUp &&
-                        links[i]->keepAliveMissed <= 1 &&
-                        links[i]->remoteNode == nodeid &&
-                        links[i]->service == OverlayInterface::OVERLAY_SERVICE_ID) {
-
-                        // mark as relay and send message
-                        links[i]->markAsRelay();
-                        return sendMessage( message, links[i] );
-                }
-
-        /// send relayed message over the overlay
-        if (!remoteRelay.isUnspecified()) {
-                // create a information relay message to inform the relay about
-                OverlayMsg overlay_msg(
-                        OverlayMsg::typeRelay, OverlayInterface::OVERLAY_SERVICE_ID, nodeId);
-                RelayMessage relayMsg( RelayMessage::typeInform, remoteRelay, nodeid, LinkID::UNSPECIFIED );
-                relayMsg.encapsulate( message );
-                overlay_msg.encapsulate( &relayMsg );
-
-                // get local relay link
-                LinkDescriptor* rld = getRelayDescriptor(nodeid);
-
-                // local relay available? send to local relay!
-                if (rld!=NULL) {
-                        rld->markAsRelay();
-                        sendMessage(&overlay_msg, rld);
-                } else
-                        overlayInterface->routeMessage(remoteRelay, &overlay_msg);
-
-                // finished
-                return 0;
-        }
-
-        // common case: send message over the overlay
-        overlayInterface->routeMessage(nodeid, message);
-        return 0;
-}
-
-/// 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 ) {
-
-                // sending a relayed message
-                logging_debug("Send: Relaying message to node "
-                        << ld->remoteNode.toString()
-                        << " using relay " << ld->localRelay
-                );
-
-                // 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 );
-                sendOverlay( &overlay_msg, ld->localRelay );
-                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 = getRelayNode(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;
-}
-
-
-// ----------------------------------------------------------------------------
+/* *****************************************************************************
+ * PUBLIC MEMBERS
+ * ****************************************************************************/
 
 use_logging_cpp(BaseOverlay);
@@ -472 +638 @@
 // ----------------------------------------------------------------------------
 
-const LinkID BaseOverlay::establishLink(
-        const EndpointDescriptor& ep, const NodeID& nodeid,
-        const ServiceID& service, const NodeID& remoteRelay, const LinkID& linkid ) {
-
-        LinkID link_id = linkid;
+const LinkID BaseOverlay::establishLink( const EndpointDescriptor& remoteEp,
+        const NodeID& remoteId, const ServiceID& service ) {
 
         // establish link via overlay
-        if (!nodeid.isUnspecified())
-                link_id = establishLink( nodeid, service, remoteRelay, link_id );
+        if (!remoteId.isUnspecified())
+                return establishLink( remoteId, service );
+        else
 
         // establish link directly if only ep is known
-        if (nodeid.isUnspecified())
-                establishDirectLink( ep, service, link_id );
-
-        return link_id;
+        if (remoteId.isUnspecified())
+                return establishDirectLink(remoteEp, service );
+
 }
 
 /// call base communication's establish link and add link mapping
 const LinkID BaseOverlay::establishDirectLink( 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();
+        const ServiceID& service ) {
 
         /// find a service listener
@@ -505 +664 @@
         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;
+        LinkDescriptor* ld = addDescriptor();
+        ld->relayed = false;
         ld->listener = listener;
         ld->service = service;
-        bc->establishLink( ep, link_id );
-
-        return link_id;
+        ld->communicationId = bc->establishLink( ep );
+
+        /// establish link and add mapping
+        logging_info("Establishing direct link " << ld->communicationId.toString()
+                << " using " << ep.toString());
+
+        return ld->communicationId;
 }
 
 /// establishes a link between two arbitrary nodes
-const LinkID BaseOverlay::establishLink( const NodeID& node,
-                const ServiceID& service, const NodeID& remoteRelay, const LinkID& link_id ) {
+const LinkID BaseOverlay::establishLink( const NodeID& remote,
+        const ServiceID& service ) {
 
         // do not establish a link to myself!
-        if (node == nodeId) return LinkID::UNSPECIFIED;
+        if (remote == nodeId) return LinkID::UNSPECIFIED;
 
         // create a link descriptor
-        LinkDescriptor* ld = createLinkDescriptor( node, service, link_id );
-        ld->remoteRelay = remoteRelay;
-
-        // 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) );
+        LinkDescriptor* ld = addDescriptor();
+        ld->relayed = true;
+        ld->remoteNode = remote;
+        ld->service = service;
+        ld->listener = getListener(ld->service);
+
+        // create link request message
+        OverlayMsg msg(OverlayMsg::typeLinkRequest, service, nodeId, remote );
+        msg.setSourceLink(ld->overlayId);
+        msg.setRelayed(true);
 
         // debug message
-        logging_debug(
+        logging_info(
                 "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
+                << " link=" << ld->overlayId.toString()
+                << " node=" << ld->remoteNode.toString()
+                << " serv=" << ld->service.toString()
         );
 
-        // sending message through new link
-        sendMessage( &overlay_msg, ld );
+        // sending message to node
+        send_node( &msg, ld->remoteNode, ld->service );
 
         return ld->overlayId;
@@ -558 +713 @@
 /// drops an established link
 void BaseOverlay::dropLink(const LinkID& link) {
-        logging_debug( "Dropping link (initiated locally):" << link.toString() );
+        logging_info( "Dropping link (initiated locally):" << link.toString() );
 
         // find the link item to drop
@@ -579 +734 @@
 
         // do not drop relay links
-        if (!ld->usedAsRelay) {
+        if (!ld->relaying) {
                 // drop the link in base communication
                 if (ld->communicationUp) bc->dropLink( ld->communicationId );
@@ -586 +741 @@
                 eraseDescriptor( ld->overlayId );
         } else
-                ld->dropWhenRelaysLeft = true;
+                ld->dropAfterRelaying = true;
 }
 
@@ -605 +760 @@
         // check if the link is up yet, if its an auto link queue message
         if( !ld->up ) {
-                ld->markAsUsed();
+                ld->setAutoUsed();
                 if( ld->autolink ) {
                         logging_info("Auto-link " << link.toString() << " not up, queue message");
@@ -618 +773 @@
 
         // compile overlay message (has service and node id)
-        OverlayMsg overmsg( OverlayMsg::typeData, ld->service, nodeId );
+        OverlayMsg overmsg( OverlayMsg::typeData );
         overmsg.encapsulate( const_cast<Message*>(message) );
 
         // send message over relay/direct/overlay
-        return sendMessage( &overmsg, ld );
+        return send_link( &overmsg, ld->overlayId );
 }
 
@@ -640 +795 @@
                 );
 
-                // 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, NodeID::UNSPECIFIED, link );
+                LinkID link = establishLink( node, service );
                 ld = getDescriptor( link );
                 if( ld == NULL ) {
@@ -658 +810 @@
 
         // mark the link as used, as we now send a message through it
-        ld->markAsUsed();
+        ld->setAutoUsed();
 
         // send / queue message
@@ -794 +946 @@
 
                 // send join request message
-                OverlayMsg overlayMsg( OverlayMsg::typeJoinRequest, nodeId );
+                OverlayMsg overlayMsg( OverlayMsg::typeJoinRequest,
+                        OverlayInterface::OVERLAY_SERVICE_ID, nodeId );
                 JoinRequest joinRequest( spovnetId, nodeId );
                 overlayMsg.encapsulate( &joinRequest );
@@ -804 +957 @@
         if (ld == NULL) {
                 ld = addDescriptor( id );
-                logging_debug( "onLinkUp (remote request) descriptor: " << ld );
+                logging_info( "onLinkUp (remote request) descriptor: " << ld );
 
                 // update descriptor
@@ -810 +963 @@
                 ld->communicationId = id;
                 ld->communicationUp = true;
-                ld->markAsUsed();
+                ld->setAutoUsed();
+                ld->setAlive();
 
                 // in this case, do not inform listener, since service it unknown
@@ -817 +971 @@
         // 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() );
+                logging_info( "onLinkUp descriptor (initiated locally):" << ld );
 
                 // update descriptor
-                ld->markAsUsed();
+                ld->setAutoUsed();
+                ld->setAlive();
                 ld->communicationUp = true;
-
-                // if link is a relayed link ->convert to direct link
-                if (ld->relay && !ld->remoteLinkId.isUnspecified() ) {
+                ld->fromRemote = false;
+
+                // if link is a relayed link->convert to direct link
+                if (ld->relayed) {
                         logging_info( "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 );
+                        ld->relayed = false;
+                        OverlayMsg overMsg( OverlayMsg::typeLinkDirect );
+                        overMsg.setSourceLink( ld->overlayId );
+                        overMsg.setDestinationLink( ld->remoteLink );
+                        send_link( &overMsg, ld->overlayId );
+                } else {
+                        // note: necessary to validate the link on the remote side!
+                        logging_info( "Sending out update" <<
+                                " for service " << ld->service.toString() <<
+                                " with local node id " << nodeId.toString() <<
+                                " on link " << ld->overlayId.toString() );
+
+                        // compile and send update message
+                        OverlayMsg overlayMsg( OverlayMsg::typeLinkUpdate );
+                        overlayMsg.setSourceLink(ld->overlayId);
+                        overlayMsg.setAutoLink( ld->autolink );
+                        send_link( &overlayMsg, ld->overlayId, true );
+                }
         }
 }
@@ -859 +1016 @@
         logging_info( "onLinkDown descriptor: " << ld );
 
+        // removing relay link information
+        removeRelayLink(ld->overlayId);
+
         // inform listeners about link down
         ld->communicationUp = false;
-        ld->listener->onLinkDown( ld->overlayId, ld->remoteNode );
-        sideport->onLinkDown( id, this->nodeId, ld->remoteNode, this->spovnetId );
+        if (!ld->service.isUnspecified()) {
+                getListener(ld->service)->onLinkDown( ld->overlayId, ld->remoteNode );
+                sideport->onLinkDown( id, this->nodeId, ld->remoteNode, this->spovnetId );
+        }
 
         // delete all queued messages (auto links)
@@ -889 +1051 @@
 
         // autolinks: refresh timestamp
-        ld->markAsUsed();
+        ld->setAutoUsed();
 }
 
@@ -908 +1070 @@
         ld->listener->onLinkFail( ld->overlayId, ld->remoteNode );
         sideport->onLinkFail( id, this->nodeId, ld->remoteNode, this->spovnetId );
-
-        // autolinks: refresh timestamp
-        ld->markAsUsed();
 }
 
@@ -921 +1080 @@
         if ( ld == NULL ) return; // not found? ->ignore!
         logging_debug( "Link quality changed id=" << ld->overlayId.toString() );
-
-        // autolinks: refresh timestamp
-        ld->markAsUsed();
 }
 
@@ -937 +1093 @@
         // 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 );
-        }
+        return handleMessage( message, ld, link );
 }
 
 // ----------------------------------------------------------------------------
 
-/// 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());
-
-        bool ret = false;
-
-        // 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() );
-                                ret = false;
-                                break;
+/// Handle spovnet instance join requests
+bool BaseOverlay::handleJoinRequest( OverlayMsg* overlayMsg, const LinkID& bcLink ) {
+
+        // 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,
+                OverlayInterface::OVERLAY_SERVICE_ID, nodeId );
+        JoinReply replyMsg( spovnetId, parameters,
+                        allow, getEndpointDescriptor() );
+        retmsg.encapsulate(&replyMsg);
+        bc->sendMessage( bcLink, &retmsg );
+
+        return true;
+}
+
+/// Handle replies to spovnet instance join requests
+bool BaseOverlay::handleJoinReply( OverlayMsg* overlayMsg, const LinkID& bcLink ) {
+        // 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() );
+                delete replyMsg;
+                return false;
+        }
+
+        // access granted? no -> fail
+        if( !replyMsg->getJoinAllowed() ) {
+                logging_error( "Our join request has been denied" );
+
+                // drop initiator link
+                if( !bcLink.isUnspecified() ){
+                        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 );
+
+                delete replyMsg;
+                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.isUnspecified() ){
+                                bc->dropLink( bcLink );
+
+                                vector<LinkID>::iterator it = std::find(
+                                                bootstrapLinks.begin(), bootstrapLinks.end(), bcLink);
+                                if( it != bootstrapLinks.end() )
+                                        bootstrapLinks.erase(it);
                         }
 
-                        // 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 );
-                        ret = true;
-                        break;
-                }
-
-                // ---------------------------------------------------------------------
-                // 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() );
-                                ret = false;
-                                delete replyMsg;
-                                break;
-                        }
-
-                        // 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 );
-
-                                ret = true;
-                                delete replyMsg;
-                                break;
-                        }
-
-                        // 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 );
+
+                        delete replyMsg;
+                        return true;
+                }
+
+                // everything ok-> join the overlay!
+                state = BaseOverlayStateCompleted;
+                overlayInterface->createOverlay();
+
+                overlayInterface->joinOverlay( replyMsg->getBootstrapEndpoint() );
+                overlayBootstrap.recordJoin( 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 );
+
+                delete replyMsg;
+
+<<<<<<< .working
                                         // inform all registered services of the event
                                         BOOST_FOREACH( NodeListener* i, nodeListeners )
                                                 i->onJoinFailed( spovnetId );
-
-                                        delete replyMsg;
-                                        ret = true;
-                                        break;
-                                }
-
-                                // 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 )
-
+=======
+        } else {
+>>>>>>> .merge-rechts.r5869
+
+                // this is not the first bootstrap, just join the additional node
+                logging_debug("not first-time bootstrapping");
+                overlayInterface->joinOverlay( replyMsg->getBootstrapEndpoint() );
+                overlayBootstrap.recordJoin( replyMsg->getBootstrapEndpoint() );
+
+                delete replyMsg;
+        } // if( overlayInterface == NULL )
+
+        return true;
+}
+
+
+<<<<<<< .working
+=======
+bool BaseOverlay::handleData( OverlayMsg* overlayMsg, LinkDescriptor* ld ) {
+        // get service
+        const ServiceID& service = overlayMsg->getService();
+        logging_debug( "Received data for service " << service.toString()
+                << " on link " << overlayMsg->getDestinationLink().toString() );
+
+>>>>>>> .merge-rechts.r5869
+        // delegate data message
+        getListener(service)->onMessage(
+                overlayMsg,
+                overlayMsg->getSourceNode(),
+                overlayMsg->getDestinationLink()
+        );
+
+        return true;
+}
+
+<<<<<<< .working
+=======
+
+>>>>>>> .merge-rechts.r5869
+bool BaseOverlay::handleLinkUpdate( OverlayMsg* overlayMsg, LinkDescriptor* ld ) {
+
+<<<<<<< .working
                         //record bootstrap ep as good endpoint to join
                         overlayBootstrap.recordJoin( replyMsg->getBootstrapEndpoint() );
@@ -1132 +1280 @@
                         break;
                 }
-
-                // ---------------------------------------------------------------------
-                // 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 ) {
-                                ret = true;
-                                break;
-                        }
-
+=======
+        if( ld == NULL ) {
+                logging_warn( "received overlay update message for link for "
+                                << "which we have no mapping" );
+                return false;
+        }
+        logging_info("Received type update message on link " << ld );
+>>>>>>> .merge-rechts.r5869
+
+        // update our link mapping information for this link
+        bool changed =
+                ( ld->remoteNode != overlayMsg->getSourceNode() )
+                || ( ld->service != overlayMsg->getService() );
+
+        // set parameters
+        ld->up         = true;
+        ld->remoteNode = overlayMsg->getSourceNode();
+        ld->remoteLink = overlayMsg->getSourceLink();
+        ld->service    = overlayMsg->getService();
+        ld->autolink   = overlayMsg->isAutoLink();
+
+        // if our link information changed, we send out an update, too
+        if( changed ) {
+                overlayMsg->swapRoles();
+                overlayMsg->setSourceNode(nodeId);
+                overlayMsg->setSourceLink(ld->overlayId);
+                overlayMsg->setService(ld->service);
+                send( overlayMsg, ld );
+        }
+
+<<<<<<< .working
                         // delegate data message
                         listener->onMessage( overlayMsg,
                                 overlayMsg->getSourceNode(), ld->overlayId );
-
-                        ret = true;
-                        break;
-                }
-
-                // ---------------------------------------------------------------------
-                // handle update messages for link establishment
-                // ---------------------------------------------------------------------
-                case OverlayMsg::typeUpdate: {
-                        // 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 for "
-                                                << "which we have no mapping" );
-                                ret = false;
-                                break;
-                        }
-                        logging_debug("Received type update message on link " << ld );
-
-                        // 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" );
-                                ret = false;
-                                break;
-                        }
-
-                        // 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!" );
-                                ret = true;
-                                break;
-                        }
-
-                        // 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 );
-                                ret = true;
-                                break;
-                        }
-
-                        // 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 );
-
-                        ret = true;
-                        break;
-                }
-
-                // ---------------------------------------------------------------------
-                // 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" );
-                                        ret = true;
-                                        break;
-                                }
-
-                                // 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);
-                                if (ldn==NULL) {
-                                        delete linkReq;
-                                        ret = true;
-                                        break;
-                                }
-
-                                // 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 );
-                        }
-                        delete linkReq;
-                        ret = true;
-                        break;
-                }
-
-                // ---------------------------------------------------------------------
-                // 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() );
-
+=======
+        // service registered? no-> error!
+        if( !communicationListeners.contains( ld->service ) ) {
+                logging_warn( "Link up: event listener has not been registered" );
+                return false;
+        }
+>>>>>>> .merge-rechts.r5869
+
+        // default or no service registered?
+        CommunicationListener* listener = communicationListeners.get( ld->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->setAutoUsed();
+        ld->setAlive();
+
+        // ask the service whether it wants to accept this link
+        if( !listener->onLinkRequest(ld->remoteNode) ) {
+
+                logging_debug("Link id=" << ld->overlayId.toString() <<
+                        " has been denied by service " << ld->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_info( "Link has been accepted by service and is up: " << ld );
+
+        // auto links: link has been accepted -> send queued messages
+        if( ld->messageQueue.size() > 0 ) {
+                logging_info( "Sending out queued messages on link " << ld );
+                BOOST_FOREACH( Message* msg, ld->messageQueue ) {
+                        sendMessage( msg, ld->overlayId );
+                        delete msg;
+                }
+                ld->messageQueue.clear();
+        }
+
+        // call the notification functions
+        listener->onLinkUp( ld->overlayId, ld->remoteNode );
+        sideport->onLinkUp( ld->overlayId, nodeId, ld->remoteNode, this->spovnetId );
+
+        return true;
+}
+
+/// handle a link request and reply
+bool BaseOverlay::handleLinkRequest( OverlayMsg* overlayMsg, LinkDescriptor* ld ) {
+        logging_info( "Link request received from node id=" << overlayMsg->getSourceNode() );
+
+        //TODO: Check if a request has already been sent using getSourceLink() ...
+
+        // create link descriptor
+        LinkDescriptor* ldn = addDescriptor();
+
+        // flags
+        ldn->up = true;
+        ldn->fromRemote = true;
+        ldn->relayed = true;
+
+        // parameters
+        ldn->service = overlayMsg->getService();
+        ldn->listener = getListener(ldn->service);
+        ldn->remoteNode = overlayMsg->getSourceNode();
+        ldn->remoteLink = overlayMsg->getSourceLink();
+
+        // update time-stamps
+        ldn->setAlive();
+        ldn->setAutoUsed();
+
+        // create reply message and send back!
+        overlayMsg->swapRoles(); // swap source/destination
+        overlayMsg->setType(OverlayMsg::typeLinkReply);
+        overlayMsg->setSourceLink(ldn->overlayId);
+        overlayMsg->setSourceEndpoint( bc->getEndpointDescriptor() );
+        overlayMsg->setRelayed(true);
+        send( overlayMsg, ld ); // send back to link
+
+        // inform listener
+        ldn->listener->onLinkUp( ldn->overlayId, ldn->remoteNode );
+
+        return true;
+}
+
+bool BaseOverlay::handleLinkReply( OverlayMsg* overlayMsg, LinkDescriptor* ld ) {
+
+        // find link request
+        LinkDescriptor* ldn = getDescriptor(overlayMsg->getDestinationLink());
+
+        // not found? yes-> drop with error!
+        if (ldn == NULL) {
+                logging_error( "No link request pending for "
+                        << overlayMsg->getDestinationLink().toString() );
+                return false;
+        }
+        logging_debug("Handling link reply for " << ldn )
+
+        // check if already up
+        if (ldn->up) {
+                logging_warn( "Link already up: " << ldn );
+                return true;
+        }
+
+        // debug message
+        logging_debug( "Link request reply received. Establishing link"
+                << " for service " << overlayMsg->getService().toString()
+                << " with local id=" << overlayMsg->getDestinationLink()
+                << " and remote link id=" << overlayMsg->getSourceLink()
+                << " to " << overlayMsg->getSourceEndpoint().toString()
+        );
+
+        // set local link descriptor data
+        ldn->up = true;
+        ldn->relayed = true;
+        ldn->service = overlayMsg->getService();
+        ldn->listener = getListener(ldn->service);
+        ldn->remoteLink = overlayMsg->getSourceLink();
+        ldn->remoteNode = overlayMsg->getSourceNode();
+
+        // update timestamps
+        ldn->setAlive();
+        ldn->setAutoUsed();
+
+        // 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();
+        }
+
+        // inform listeners about new link
+        ldn->listener->onLinkUp( ldn->overlayId, ldn->remoteNode );
+
+        // try to replace relay link with direct link
+        ldn->communicationId =
+                bc->establishLink( overlayMsg->getSourceEndpoint() );
+
+        return true;
+}
+
+<<<<<<< .working
+=======
+/// handle a keep-alive message for a link
+bool BaseOverlay::handleLinkAlive( OverlayMsg* overlayMsg, LinkDescriptor* ld ) {
+        LinkDescriptor* rld = getDescriptor(overlayMsg->getDestinationLink());
+        if ( rld != NULL ) {
+                logging_debug("Keep-Alive for " <<
+                        overlayMsg->getDestinationLink() );
+                if (overlayMsg->isRouteRecord())
+                        rld->routeRecord = overlayMsg->getRouteRecord();
+                rld->setAlive();
+                return true;
+        } else {
+                logging_error("Keep-Alive for "
+                                << overlayMsg->getDestinationLink() << ": link unknown." );
+                return false;
+        }
+}
+
+/// handle a direct link message
+bool BaseOverlay::handleLinkDirect( OverlayMsg* overlayMsg, LinkDescriptor* ld ) {
+        logging_debug( "Received direct link replacement request" );
+
+>>>>>>> .merge-rechts.r5869
+        /// get destination overlay link
+        LinkDescriptor* rld = getDescriptor( overlayMsg->getDestinationLink() );
+        if (rld == NULL || ld == NULL) {
+                logging_error("Direct link replacement: Link "
+                                << overlayMsg->getDestinationLink() << "not found error." );
+                return false;
+        }
+        logging_info( "Received direct link convert notification for " << rld );
+
+        // update information
+        rld->communicationId = ld->communicationId;
+        rld->communicationUp = true;
+        rld->relayed = false;
+
+<<<<<<< .working
                                         // mark incoming link as relay
                                         if (ld!=NULL) ld->markAsRelay();
@@ -1417 +1523 @@
                                         _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() );
-                                                sendOverlay( &_overMsg, relayMsg->getDestNode() );
-                                        } else {
-                                                logging_info("Routing relay message to " << relayMsg->getRelayNode().toString() );
-                                                sendOverlay( &_overMsg, relayMsg->getRelayNode() );
-                                        }
-                                        ret = true;
-                                        break;
-                                }
-
-                                // handle relay routing
-                                case RelayMessage::typeRoute: {
-                                        logging_info("Received relay route message with"
-                                                        << " relay " << relayMsg->getRelayNode()
-                                                        << " destination " << relayMsg->getDestNode() );
-
+=======
+        // mark used and alive!
+        rld->setAlive();
+        rld->setAutoUsed();
+>>>>>>> .merge-rechts.r5869
+
+        // erase the original descriptor
+        eraseDescriptor(ld->overlayId);
+}
+
+/// handles an incoming message
+bool BaseOverlay::handleMessage( const Message* message, LinkDescriptor* ld,
+        const LinkID bcLink ) {
+        logging_debug( "Handling message: " << message->toString());
+
+<<<<<<< .working
                                         // mark incoming link as relay
                                         if (ld!=NULL) ld->markAsRelay();
@@ -1454 +1557 @@
                                                 RelayMessage _relayMsg( *relayMsg );
                                                 _overMsg.encapsulate(&_relayMsg);
-
-                                                /// this must be handled by using relay link!
-                                                sendOverlay(&_overMsg, relayMsg->getDestNode());
-                                                ret = true;
-                                                break;
-                                        }
-
-                                        // error: I'm not a relay or destination!
-                                        logging_error("This node is neither relay nor destination. Dropping Message!");
-                                        ret = true;
-                                        break;
-                                }
-                                default: {
-                                        logging_error("RelayMessage Unknown!");
-                                        ret = true;
-                                        break;
-                                }
-                        }
-                        delete relayMsg;
-                        break;
-                }
-
-                // ---------------------------------------------------------------------
-                // handle keep-alive messages
-                // ---------------------------------------------------------------------
-                case OverlayMsg::typeKeepAlive: {
-                        logging_debug( "received keep-alive on link" );
-                        if ( ld != NULL ) {
-                                logging_info("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() );
-                        if (rld == NULL || ld == NULL) {
-                                logging_error("Direct link replacement: Link "
-                                                << overlayMsg->getRelayLink() << "not found error." );
-                                break;
-                        }
-                        logging_info( "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;
-                }
-
-                // ---------------------------------------------------------------------
+=======
+        // decapsulate overlay message
+        OverlayMsg* overlayMsg =
+                const_cast<Message*>(message)->decapsulate<OverlayMsg>();
+        if( overlayMsg == NULL ) return false;
+>>>>>>> .merge-rechts.r5869
+
+        // refresh relay information
+        refreshRelayInformation( overlayMsg, ld );
+
+        // increase number of hops
+        overlayMsg->increaseNumHops();
+
+        // update route record
+        overlayMsg->addRouteRecord(nodeId);
+
+        // handle signaling messages (do not route!)
+        if (overlayMsg->getType()>=OverlayMsg::typeSignalingStart &&
+                overlayMsg->getType()<=OverlayMsg::typeSignalingEnd ) {
+                overlayInterface->onMessage(overlayMsg, NodeID::UNSPECIFIED, LinkID::UNSPECIFIED);
+                delete overlayMsg;
+                return true;
+        }
+
+        // message for reached destination? no-> route message
+        if (!overlayMsg->getDestinationNode().isUnspecified() &&
+                 overlayMsg->getDestinationNode() != nodeId ) {
+                logging_debug("Routing message "
+                        << " from " << overlayMsg->getSourceNode()
+                        << " to " << overlayMsg->getDestinationNode()
+                );
+
+                route( overlayMsg, ld );
+                delete overlayMsg;
+                return true;
+        }
+
+        // handle base overlay message
+        bool ret = false; // return value
+        switch ( overlayMsg->getType() ) {
+
+                // data transport messages
+                case OverlayMsg::typeData:
+                        ret = handleData(overlayMsg, ld);                       break;
+
+                // overlay setup messages
+                case OverlayMsg::typeJoinRequest:
+                        ret = handleJoinRequest(overlayMsg, bcLink );   break;
+                case OverlayMsg::typeJoinReply:
+                        ret = handleJoinReply(overlayMsg, bcLink );     break;
+
+                // link specific messages
+                case OverlayMsg::typeLinkRequest:
+                        ret = handleLinkRequest(overlayMsg, ld );       break;
+                case OverlayMsg::typeLinkReply:
+                        ret = handleLinkReply(overlayMsg, ld );         break;
+                case OverlayMsg::typeLinkUpdate:
+                        ret = handleLinkUpdate(overlayMsg, ld );        break;
+                case OverlayMsg::typeLinkAlive:
+                        ret = handleLinkAlive(overlayMsg, ld );         break;
+                case OverlayMsg::typeLinkDirect:
+                        ret = handleLinkDirect(overlayMsg, ld );        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() );
+                                "what to do with this message of type " << overlayMsg->getType() );
                         ret = false;
                         break;
                 }
-        } /* switch */
-
+        }
+
+        // free overlay message and return value
         delete overlayMsg;
         return ret;
@@ -1554 +1649 @@
 }
 
+/// return the overlay neighbors
 vector<NodeID> BaseOverlay::getOverlayNeighbors(bool deep) const {
 
         vector<NodeID> nodes = overlayInterface->getKnownNodes(deep);
-
         // the known nodes _can_ also include our node, so we remove ourself
         vector<NodeID>::iterator i = find( nodes.begin(), nodes.end(), this->nodeId );
         if( i != nodes.end() ) nodes.erase( i );
-
         return nodes;
 }
@@ -1594 +1688 @@
 
 void BaseOverlay::eventFunction() {
+<<<<<<< .working
 
         // send keep-alive messages over established links
@@ -1673 +1768 @@
         if (counter>=4) showLinkState();
         if (counter>=4 || counter<0) counter = 0;
-}
-
-void BaseOverlay::showLinkState() {
-        int i=0;
-        logging_info("--- link state -------------------------------");
-        BOOST_FOREACH( LinkDescriptor* ld, links ) {
-                logging_info("link " << i << ": " << ld);
-                i++;
-        }
-        logging_info("----------------------------------------------");
+=======
+        stabilizeRelays();
+        stabilizeLinks();
+>>>>>>> .merge-rechts.r5869
 }