source: source/ariba/communication/BaseCommunication.cpp@ 12745

// [License]
// 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.
// [License]

#include "BaseCommunication.h"

#include "networkinfo/AddressDiscovery.h"
#include "ariba/utility/types/PeerID.h"
#include "ariba/utility/system/SystemQueue.h"
#include <boost/function.hpp>

#ifdef UNDERLAY_OMNET
  #include "ariba/communication/modules/transport/omnet/AribaOmnetModule.h"
  #include "ariba/communication/modules/network/omnet/OmnetNetworkProtocol.h"
  #include "ariba/utility/system/StartupWrapper.h"

  using ariba::communication::AribaOmnetModule;
  using ariba::communication::OmnetNetworkProtocol;
  using ariba::utility::StartupWrapper;
#endif

namespace ariba {
namespace communication {

using namespace ariba::addressing2;

using ariba::utility::PeerID;
using ariba::utility::SystemQueue;

use_logging_cpp(BaseCommunication);


BaseCommunication::BaseCommunication() 
        : currentSeqnum( 0 ),
          transport( NULL ),
          messageReceiver( NULL ),
          started( false ),
          listenOn_endpoints(new addressing2::endpoint_set())
{
}


BaseCommunication::~BaseCommunication(){
}


void BaseCommunication::start(EndpointSetPtr listen_on) {
    assert ( ! started );
    
    listenOn_endpoints = listen_on;
    logging_info("Setting local end-points: " << listenOn_endpoints->to_string());
    
        logging_info( "Starting up ..." );
        currentSeqnum = 0;

        // creating transports
        //  ---> transport_peer holds the set of the active endpoints we're listening on
        logging_info( "Creating transports ..." );
        transport = new transport_peer();
        active_listenOn_endpoints = transport->add_listenOn_endpoints(listenOn_endpoints);
        logging_info( "XXX. Active endpoints = " << active_listenOn_endpoints->to_string() ); // XXX

        logging_info( "Searching for local locators ..." );
        local_endpoints = AddressDiscovery::discover_endpoints(active_listenOn_endpoints);
        if ( local_endpoints->count() > 0 )
        {
            logging_info( "Done. Discovered local endpoints: " << local_endpoints->to_string() );
        }
        else
        {
            logging_warn("WARING!! No local endpoints found, NO COMMUNICATION POSSIBLE!!");
            
            // TODO notify application, so that it may react properly. throw exception..?
            assert( false );
        }

        
    // create local EndpointDescriptor
        //  ---> localDescriptor hold the set endpoints that can be used to reach us
    localDescriptor.getPeerId() = PeerID::random();
    localDescriptor.replace_endpoint_set(local_endpoints);
    logging_info( "Using PeerID: " << localDescriptor.getPeerId() );

    // start transport_peer
        transport->register_listener( this );
        transport->start();

        // bind to the network change detection
        networkMonitor.registerNotification( this );

        // base comm startup done
        started = true;
        logging_info( "Started up." );
}

void BaseCommunication::stop() {
        logging_info( "Stopping transports ..." );

        transport->stop();
        delete transport;
        started = false;

        logging_info( "Stopped." );
}

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

const LinkID BaseCommunication::establishLink(
        const EndpointDescriptor& descriptor,
        const LinkID& link_id,
        const QoSParameterSet& qos,
        const SecurityParameterSet& sec) {

        // copy link id
        LinkID linkid = link_id;

        // debug
        logging_debug( "Request to establish link" );

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

        // create link descriptor
        logging_debug( "Creating new descriptor entry with local link id=" << linkid.toString() );
        LinkDescriptor* ld = new LinkDescriptor();
        ld->localLink = linkid;
        addLink( ld );


    /* send a message to request new link to remote */
    logging_debug( "Send messages with request to open link to " << descriptor.toString() );

    /*
         * Create Link-Request Message:
         * NOTE: - Their PeerID (in parent message)
         * - Our LinkID
         * - Our PeerID
         * - Our EndpointDescriptor
         */
        reboost::message_t linkmsg;
        linkmsg.push_back(linkid.serialize());
        linkmsg.push_back(localDescriptor.getPeerId().serialize());
        linkmsg.push_back(localDescriptor.endpoints->serialize());
        
//      // XXX AKTUELL BUG FINDING...
//      reboost::shared_buffer_t xxx = localDescriptor.endpoints->serialize();
//      EndpointSetPtr xxx_set = endpoint_set::create_EndpointSet();
//      xxx_set->deserialize(xxx);
//      cout << "/// MARIO VORHER: " << localDescriptor.endpoints->to_string() << endl;
//      cout << "/// MARIO NACHHER: " << xxx_set->to_string() << endl;
        
        // send message
        // TODO move enum to BaseComm
        send_to_peer(AribaBaseMsg::typeLinkRequest, descriptor.getPeerId(), linkmsg,
                descriptor, system_priority::OVERLAY);

        return linkid;
}

void BaseCommunication::dropLink(const LinkID link) {

        logging_debug( "Starting to drop link " + link.toString() );

        // see if we have the link
        LinkDescriptor& ld = queryLocalLink( link );
        if( ld.isUnspecified() ) {
                logging_error( "Don't know the link you want to drop "+ link.toString() );
                return;
        }

        // tell the registered listeners
        foreach( CommunicationEvents* i, eventListener ) {
                i->onLinkDown( link, ld.localLocator, ld.remoteLocator );
        }


        // * send message to drop the link *
        logging_debug( "Sending out link close request. for us, the link is closed now" );
        reboost::message_t empty_message;
        send_over_link( AribaBaseMsg::typeLinkClose, empty_message, ld, system_priority::OVERLAY );

        // remove from map
        removeLink(link);
}


seqnum_t BaseCommunication::sendMessage( const LinkID& lid,
        reboost::message_t message,
        uint8_t priority,
        bool bypass_overlay) throw(communication_message_not_sent)
{
    // message type: direct data or (normal) data 
    AribaBaseMsg::type_ type;
    if ( bypass_overlay )
    {
        type = AribaBaseMsg::typeDirectData;
        logging_debug( "Sending out direct-message to link " << lid.toString() );
    }
    else
    {
        type = AribaBaseMsg::typeData;
        logging_debug( "Sending out message to link " << lid.toString() );
    }

    
        // query local link info
        LinkDescriptor& ld = queryLocalLink(lid);
        if( ld.isUnspecified() )
        {
            throw communication_message_not_sent("Don't know the link with id "
                    + lid.toString());
        }

        // link not up-> error
        if( !ld.up )
        {
            throw communication_message_not_sent("Can not send on link "
                    + lid.toString() + ": link not up");
        }


        // * send message *
        bool okay = send_over_link( type, message, ld, priority );

        if ( ! okay )
        {
            throw communication_message_not_sent("send_over_link failed!");
        }
        
        return ++currentSeqnum;
}

const EndpointDescriptor& BaseCommunication::getEndpointDescriptor(const LinkID link) const {
        if( link.isUnspecified() ){
                return localDescriptor;
        } else {
                LinkDescriptor& linkDesc = queryLocalLink(link);
                if (linkDesc.isUnspecified()) return EndpointDescriptor::UNSPECIFIED();
                return linkDesc.remoteDescriptor;
        }
}

void BaseCommunication::registerEventListener(CommunicationEvents* _events){
        if( eventListener.find( _events ) == eventListener.end() )
                eventListener.insert( _events );
}

void BaseCommunication::unregisterEventListener(CommunicationEvents* _events){
        EventListenerSet::iterator i = eventListener.find( _events );
        if( i != eventListener.end() )
                eventListener.erase( i );
}



/*------------------------------
 | ASIO thread --> SystemQueue |
 ------------------------------*/

/// ASIO thread
void BaseCommunication::receive_message(transport_connection::sptr connection,
        reboost::shared_buffer_t msg) {

        logging_debug( "Dispatching message" );
        
    SystemQueue::instance().scheduleCall(
            boost::bind(
                    &BaseCommunication::receiveMessage,
                    this,
                    connection,
                    msg)
        );
}

/// ASIO thread
void BaseCommunication::connection_terminated(transport_connection::sptr connection)
{
    SystemQueue::instance().scheduleCall(
            boost::bind(
                    &BaseCommunication::connectionTerminated,
                    this,
                    connection)
        );
}

/*--------------------------------
 | [ASIO thread --> SystemQueue] |
 -------------------------------*/

/// ARIBA thread (System Queue)
void BaseCommunication::connectionTerminated(transport_connection::sptr connection)
{
    vector<LinkID*> links = connection->get_communication_links();
    
    logging_debug("[BaseCommunication] Connection terminated: "
            << connection->getLocalEndpoint()->to_string()
            << " <--> " << connection->getRemoteEndpoint()->to_string()
            << " (" << links.size() << " links)");
    
    // remove all links that used the terminated connection
    for ( vector<LinkID*>::iterator it = links.begin(); it != links.end(); ++it )
    {
        LinkID& link_id = **it;
        
        logging_debug("  ---> Removing link: " << link_id.toString());
        
        // searching for link, not found-> warn
        LinkDescriptor& linkDesc = queryLocalLink( link_id );
        if (linkDesc.isUnspecified()) {
            logging_warn("Failed to find local link " << link_id.toString());
            continue;
        }

        // inform listeners
        foreach( CommunicationEvents* i, eventListener ){
            i->onLinkFail( linkDesc.localLink,
                    linkDesc.localLocator, linkDesc.remoteLocator );
        }

        // remove the link descriptor
        removeLink( link_id );
    }
}

/// ARIBA thread (System Queue)
void BaseCommunication::receiveMessage(transport_connection::sptr connection,
        reboost::shared_buffer_t message)
{
    // XXX
    logging_debug("/// [receiveMessage] buffersize: " << message.size());
        
    // get type
    uint8_t type = message.data()[0];
    reboost::shared_buffer_t sub_buff = message(1);
    
    // get link id
    LinkID link_id;
    if ( type != AribaBaseMsg::typeLinkRequest)
    {
        sub_buff = link_id.deserialize(sub_buff);
    }
    
        // handle message
        switch ( type )
        {
                // ---------------------------------------------------------------------
                // data message
                // ---------------------------------------------------------------------
                case AribaBaseMsg::typeData:
                {
                        logging_debug( "Received data message, forwarding to overlay." );
                        if( messageReceiver != NULL )
                        {
                                messageReceiver->receiveMessage(
                                        sub_buff, link_id, NodeID::UNSPECIFIED, false
                                );
                        }
                        
                        break;
                }

        // ---------------------------------------------------------------------
        // direct data message (bypass overlay-layer)
        // ---------------------------------------------------------------------
        case AribaBaseMsg::typeDirectData:
        {
            logging_debug( "Received direct data message, forwarding to application." );
            
            if( messageReceiver != NULL )
            {
                messageReceiver->receiveMessage(
                    sub_buff, link_id, NodeID::UNSPECIFIED, true
                );
            }
            
            break;
        }


        
                // ---------------------------------------------------------------------
                // handle link request from remote
                // ---------------------------------------------------------------------
                case AribaBaseMsg::typeLinkRequest:
                {
                        logging_debug( "Received link open request on "
                                << connection->getLocalEndpoint()->to_string() );
                        
                        /*
                         * Deserialize Peer Message
                         * - Our PeerID 
                         */
                        PeerID our_peer_id;
                        sub_buff = our_peer_id.deserialize(sub_buff);

            /// not the correct peer id-> skip request
            if ( our_peer_id != localDescriptor.getPeerId() &&
                    ! our_peer_id.isUnspecified() /* overlay bootstrap */ )
            {
                logging_info("Received link request for "
                    << our_peer_id.toString()
                    << "but i'm "
                    << localDescriptor.getPeerId()
                    << ": Ignoring!");
                
                // TODO terminate connection?
                
                break;
            }

            
                    /*
                     * Deserialize Link-Request Message:
                     * - Their LinkID
                     * - Their PeerID
                     * - Their EndpointDescriptor
                     */
            LinkID their_link_id;
            PeerID their_peer_id;
            EndpointSetPtr their_endpoints = endpoint_set::create_EndpointSet();
            sub_buff = their_link_id.deserialize(sub_buff);
            sub_buff = their_peer_id.deserialize(sub_buff);
            sub_buff = their_endpoints->deserialize(sub_buff);
            /* [ Deserialize Link-Request Message ] */

            
                        /// only answer the first request
                        if (!queryRemoteLink(their_link_id).isUnspecified())
                        {
                            
                            // TODO aktuell: When will these connections be closed?
                            // ---> Close it now (if it services no links) ?
                            //   (see also ! allowlink below)
                            
                            // XXX AKTUELL TESTING !! This will cause race conditions. So this is test-code only!
                            if ( connection->get_communication_links().size() == 0 )
                            {
                                connection->terminate();
                            }
                            
                                logging_debug("Link request already received. Ignore!");
                                break;
                        }

                        /// create link ids
                        LinkID localLink  = LinkID::create();
                        LinkID remoteLink = their_link_id;  // XXX intermediate variable is unnecessary
                        logging_debug(
                                "local=" << connection->getLocalEndpoint()->to_string()
                                << " remote=" << connection->getRemoteEndpoint()->to_string()
                        );

                        // check if link creation is allowed by ALL listeners
                        bool allowlink = true;
                        foreach( CommunicationEvents* i, eventListener ){
                                allowlink &= i->onLinkRequest( localLink,
                                        connection->getLocalEndpoint(),
                                        connection->getRemoteEndpoint());
                        }

                        // not allowed-> warn
                        if( !allowlink ){
                                logging_warn( "Overlay denied creation of link" );
                                return;
                        }

                        // create descriptor
                        LinkDescriptor* ld = new LinkDescriptor();
                        ld->localLink = localLink;
                        ld->remoteLink = remoteLink;
                        ld->localLocator = connection->getLocalEndpoint();
                        ld->remoteLocator = connection->getRemoteEndpoint();
                        ld->remoteDescriptor = EndpointDescriptor(their_peer_id, their_endpoints);
                        ld->set_connection(connection);

            
                        // update endpoints (should only have any effect in case of NAT)
                        ld->remoteDescriptor.endpoints->add_endpoint(connection->getRemoteEndpoint());
//                      localDescriptor.endpoints->add_endpoint(connection->getLocalEndpoint());  // XXX 0.0.0.0:0

                        // link is now up-> add it
                        ld->up = true;
                        addLink(ld);


                        
            /* sending link reply */
            logging_debug( "Sending link reply with ids "
                << "local=" << localLink.toString() << ", "
                << "remote=" << remoteLink.toString() );

                    /*
                     * Create Link-Reply Message:
                     * - Our LinkID
                     * - Our Endpoint_Set (as update)
                     * - Their EndpointDescriptor (maybe they learn something about NAT)
                     */
                    reboost::message_t linkmsg;
                    linkmsg.push_back(localLink.serialize());
                    linkmsg.push_back(localDescriptor.endpoints->serialize());
                    linkmsg.push_back(ld->remoteDescriptor.endpoints->serialize());
                    
                    // XXX
                    cout << "/// MARIO: " << ld->get_connection()->getRemoteEndpoint()->to_string() << endl;
                    
                    // send message
                        bool sent = send_over_link( AribaBaseMsg::typeLinkReply, linkmsg, *ld, system_priority::OVERLAY );
                        
                        if ( ! sent )
                        {
                            logging_error("ERROR: Could not send LinkReply to: " << ld->remoteLocator->to_string());
                            
                            // TODO remove link, close link, ..?
                            
                            break;
                        }


            // link is up!
            logging_debug( "Link (initiated from remote) is up with "
                << "local(id=" << ld->localLink.toString() << ","
                << "locator=" << ld->localLocator->to_string() << ") "
                << "remote(id=" << ld->remoteLink.toString() << ", "
                << "locator=" << ld->remoteLocator->to_string() << ")"
            );

                        // inform listeners about new open link
                        foreach( CommunicationEvents* i, eventListener ) {
                                i->onLinkUp( localLink, ld->localLocator, ld->remoteLocator);
                        }

                        // done
                        break;
                }

                // ---------------------------------------------------------------------
                // handle link request reply
                // ---------------------------------------------------------------------
                case AribaBaseMsg::typeLinkReply:
                {
                        logging_debug( "Received link open reply for a link we initiated" );

            /*
             * Deserialize Link-Reply Message:
             * - Their LinkID
             * - Their Endpoint_Set (as update)
             * - Our EndpointDescriptor (maybe we can learn something about NAT)
             */
                        LinkID their_link_id;
                        EndpointSetPtr their_endpoints = endpoint_set::create_EndpointSet();
                        EndpointSetPtr our_endpoints = endpoint_set::create_EndpointSet();
                        sub_buff = their_link_id.deserialize(sub_buff);
                        sub_buff = their_endpoints->deserialize(sub_buff);
                        sub_buff = our_endpoints->deserialize(sub_buff);

            
                        // this is a reply to a link open request, so we have already
                        // a link mapping and can now set the remote link to valid
                        LinkDescriptor& ld = queryLocalLink( link_id );

                        // no link found-> warn!
                        if (ld.isUnspecified()) {
                                logging_warn("Failed to find local link " << link_id.toString());
                                return;
                        }
                        
                        if ( ld.up )
                        {
                logging_warn("Got link replay for already open link. Ignore. LinkID: " << link_id.toString());
                
                // TODO send LinkClose ?
                return;                     
                        }

                        // store the connection
                        ld.set_connection(connection);
                        
                        // set remote locator and link id
                        ld.remoteLink = their_link_id;
                        ld.remoteLocator = connection->getRemoteEndpoint();
                        
                        
                        /* Update endpoints */
                        // NOTE: we might loose some information here, but it's our only chance to get rid of outdated information.
                        ld.remoteDescriptor.replace_endpoint_set(their_endpoints);
                        
                        // add actual remote endpoint to this set (should only have any effect in case of NAT)
                        ld.remoteDescriptor.endpoints->add_endpoint(connection->getRemoteEndpoint());
                        
                        // TODO In case of NAT, we could learn something about our external IP.
                        //   ---> But we must trust the remote peer about this information!!  
//                      localDescriptor.endpoints->add_endpoints(our_endpoints);
                        
                        
                        
                        
                        ld.up = true;

                        logging_debug( "Link is now up with local id "
                                << ld.localLink.toString() << " and remote id "
                                << ld.remoteLink.toString() );


                        // inform lisneters about link up event
                        foreach( CommunicationEvents* i, eventListener ){
                                i->onLinkUp( ld.localLink, ld.localLocator, ld.remoteLocator );
                        }

                        // done
                        break;
                }

                // ---------------------------------------------------------------------
                // handle link close requests
                // ---------------------------------------------------------------------
                case AribaBaseMsg::typeLinkClose: {
                        // get remote link
//                      const LinkID& localLink = msg.getRemoteLink();
                        logging_debug( "Received link close request for link " << link_id.toString() );

                        // searching for link, not found-> warn
                        LinkDescriptor& linkDesc = queryLocalLink( link_id );
                        if (linkDesc.isUnspecified()) {
                                logging_warn("Failed to find local link " << link_id.toString());
                                return;
                        }

                        // inform listeners
                        foreach( CommunicationEvents* i, eventListener ){
                                i->onLinkDown( linkDesc.localLink,
                                                linkDesc.localLocator, linkDesc.remoteLocator );
                        }

                        // remove the link descriptor
                        removeLink( link_id );

                        // done
                        break;
                }

                // ---------------------------------------------------------------------
                // handle link locator changes  -- TODO is this ever called..?
                // ---------------------------------------------------------------------
//              case AribaBaseMsg::typeLinkUpdate: {
//                      const LinkID& localLink = msg.getRemoteLink();
//                      logging_debug( "Received link update for link "
//                              << localLink.toString() );
//
//                      // find the link description
//                      LinkDescriptor& linkDesc = queryLocalLink( localLink );
//                      if (linkDesc.isUnspecified()) {
//                              logging_warn("Failed to update local link "
//                                      << localLink.toString());
//                              return;
//                      }
//
//                      // update the remote locator
//                      addressing2::EndpointPtr oldremote = linkDesc.remoteLocator;
//                      linkDesc.remoteLocator = connection->getRemoteEndpoint();
//                      
//                      // TODO update linkDesc.connection ?
//
//                      // inform the listeners (local link has _not_ changed!)
//                      foreach( CommunicationEvents* i, eventListener ){
//                              i->onLinkChanged(
//                                      linkDesc.localLink,     // linkid
//                                      linkDesc.localLocator,  // old local
//                                      linkDesc.localLocator,  // new local
//                                      oldremote,                      // old remote
//                                      linkDesc.remoteLocator  // new remote
//                              );
//                      }
//
//                      // done
//                      break;
//              }
                
                
        default: {
            logging_warn( "Received unknown message type!" );
            break;
        }

        }
}

/// add a newly allocated link to the set of links
void BaseCommunication::addLink( LinkDescriptor* link ) {
        linkSet.push_back( link );
}

/// remove a link from set
void BaseCommunication::removeLink( const LinkID& localLink ) {
        for(LinkSet::iterator i=linkSet.begin(); i != linkSet.end(); i++){
                if( (*i)->localLink != localLink) continue;
//              remove_endpoint((*i)->remoteLocator);  // XXX
                delete *i;
                linkSet.erase( i );
                break;
        }
}

/// query a descriptor by local link id
BaseCommunication::LinkDescriptor& BaseCommunication::queryLocalLink( const LinkID& link ) const {
        for (size_t i=0; i<linkSet.size();i++)
                if (linkSet[i]->localLink == link) return (LinkDescriptor&)*linkSet[i];

        return LinkDescriptor::UNSPECIFIED();
}

/// query a descriptor by remote link id
BaseCommunication::LinkDescriptor& BaseCommunication::queryRemoteLink( const LinkID& link ) const {
        for (size_t i=0; i<linkSet.size();i++)
                if (linkSet[i]->remoteLink == link) return (LinkDescriptor&)*linkSet[i];

        return LinkDescriptor::UNSPECIFIED();
}

//LinkIDs BaseCommunication::getLocalLinks( const address_v* addr ) const {
//      LinkIDs ids;
//      for (size_t i=0; i<linkSet.size(); i++){
//              if( addr == NULL ){
//                      ids.push_back( linkSet[i]->localLink );
//              } else {
//                      if ( *linkSet[i]->remoteLocator == *addr )
//                              ids.push_back( linkSet[i]->localLink );
//              }
//      }
//      return ids;
//}

void BaseCommunication::onNetworkChange(const NetworkChangeInterface::NetworkChangeInfo& info){

/*- disabled!

        // we only care about address changes, not about interface changes
        // as address changes are triggered by interface changes, we are safe here
        if( info.type != NetworkChangeInterface::EventTypeAddressNew &&
                info.type != NetworkChangeInterface::EventTypeAddressDelete ) return;

        logging_info( "base communication is handling network address changes" );

        // get all now available addresses
        NetworkInformation networkInformation;
        AddressInformation addressInformation;

        NetworkInterfaceList interfaces = networkInformation.getInterfaces();
        AddressList addresses;

        for( NetworkInterfaceList::iterator i = interfaces.begin(); i != interfaces.end(); i++ ){
                AddressList newaddr = addressInformation.getAddresses(*i);
                addresses.insert( addresses.end(), newaddr.begin(), newaddr.end() );
        }

        //
        // get current locators for the local endpoint
        // TODO: this code is dublicate of the ctor code!!! cleanup!
        //

        NetworkProtocol::NetworkLocatorSet locators = network->getAddresses();
        NetworkProtocol::NetworkLocatorSet::iterator i = locators.begin();
        NetworkProtocol::NetworkLocatorSet::iterator iend = locators.end();

        //
        // remember the old local endpoint, in case it changes
        //

        EndpointDescriptor oldLocalDescriptor( localDescriptor );

        //
        // look for local locators that we can use in communication
        //
        // choose the first locator that is not localhost
        //

        bool foundLocator = false;
        bool changedLocator = false;

        for( ; i != iend; i++){
                logging_debug( "local locator found " << (*i)->toString() );
                IPv4Locator* ipv4locator = dynamic_cast<IPv4Locator*>(*i);

                if( *ipv4locator != IPv4Locator::LOCALHOST &&
                    *ipv4locator != IPv4Locator::ANY       &&
                    *ipv4locator != IPv4Locator::BROADCAST  ){

                        ipv4locator->setPort( listenport );
                        changedLocator = *localDescriptor.locator != *ipv4locator;
                        localDescriptor.locator = ipv4locator;
                        logging_info( "binding to addr = " << ipv4locator->toString() );
                        foundLocator = true;
                        break;
                }
        } // for( ; i != iend; i++)

        //
        // if we found no locator, bind to localhost
        //

        if( !foundLocator ){
                changedLocator = *localDescriptor.locator != IPv4Locator::LOCALHOST;
                localDescriptor.locator = new IPv4Locator( IPv4Locator::LOCALHOST );
                ((IPv4Locator*)(localDescriptor.locator))->setPort( listenport );
                logging_info( "found no good local lcoator, binding to addr = " <<
                                                localDescriptor.locator->toString() );
        }

        //
        // if we have connections that have no more longer endpoints
        // close these. they will be automatically built up again.
        // also update the local locator in the linkset mapping
        //

        if( changedLocator ){

                logging_debug( "local endp locator has changed to " << localDescriptor.toString() <<
                                ", resettings connections that end at old locator " <<
                                        oldLocalDescriptor.toString());

                LinkSet::iterator i = linkSet.begin();
                LinkSet::iterator iend = linkSet.end();

                for( ; i != iend; i++ ){

                        logging_debug( "checking connection for locator change: " <<
                                        " local " << (*i).localLocator->toString() <<
                                        " old " << oldLocalDescriptor.locator->toString() );

                        if( *((*i).localLocator) == *(oldLocalDescriptor.locator) ){

                                logging_debug("terminating connection to " << (*i).remoteLocator->toString() );
                                transport->terminate( oldLocalDescriptor.locator, (*i).remoteLocator );

                                (*i).localLocator = localDescriptor.locator;
                        }
                } // for( ; i != iend; i++ )

                // wait 500ms to give the sockets time to shut down
                usleep( 500000 );

        } else {

                logging_debug( "locator has not changed, not resetting connections" );

        }

        //
        // handle the connections that have no longer any
        // valid locator. send update messages with the new
        // locator,  so the remote node updates its locator/link mapping
        //

        LinkSet::iterator iAffected = linkSet.begin();
        LinkSet::iterator endAffected = linkSet.end();

        for( ; iAffected != endAffected; iAffected++ ){
                LinkDescriptor descr = *iAffected;
                logging_debug( "sending out link locator update to " << descr.remoteLocator->toString() );

                AribaBaseMsg updateMsg(         descr.remoteLocator,
                                                AribaBaseMsg::LINK_STATE_UPDATE,
                                                descr.localLink, descr.remoteLink );

                transport->sendMessage( &updateMsg );
        }
*/
}


addressing2::EndpointPtr BaseCommunication::get_local_endpoint_of_link(
        const LinkID& linkid)
{
    LinkDescriptor& ld = queryLocalLink(linkid);
    
    return ld.get_connection()->getLocalEndpoint();
}

addressing2::EndpointPtr BaseCommunication::get_remote_endpoint_of_link(
        const LinkID& linkid)
{
    LinkDescriptor& ld = queryLocalLink(linkid);
    
    return ld.get_connection()->getRemoteEndpoint();
}



bool BaseCommunication::send_over_link(
        const uint8_t type,
        reboost::message_t message,
        const LinkDescriptor& desc,
        const uint8_t priority)
{
    /*
     * Create Link Message:
     * - Type
     * - Their LinkID
     */
    // link id
    message.push_front(desc.remoteLink.serialize());
    // type
    memcpy(message.push_front(sizeof(uint8_t)).mutable_data(), &type, sizeof(uint8_t));
    /* [ Create Link Message ] */
    
    
    /* send message */
    transport_connection::sptr conn = desc.get_connection();
    if ( ! conn )
    {
        cout << "/// MARIO: No connection!!" << endl;  // XXX debug
        return false;
    }
    
    // * send over connection *
    return conn->send(message, priority);
}

void BaseCommunication::send_to_peer(
        const uint8_t type,
        const PeerID& peer_id,
        reboost::message_t message,
        const EndpointDescriptor& endpoint,
        const uint8_t priority )
{
    /*
     * Create Peer Message:
     * - Type
     * - Their PeerID
     */
    // peer id
    message.push_front(peer_id.serialize());
    // type
    memcpy(message.push_front(sizeof(uint8_t)).mutable_data(), &type, sizeof(uint8_t));
    
    
    /* send message */
    transport->send(endpoint.getEndpoints(), message, priority);
}




}} // namespace ariba, communication