NodeHandshakeExtension.cpp

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/*
 * NodeHandshakeExtension.cpp
 *
 * Copyright (C) 2011 IBR, TU Braunschweig
 *
 * Written-by: Johannes Morgenroth <morgenroth@ibr.cs.tu-bs.de>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "routing/NodeHandshakeExtension.h"
#include "routing/NodeHandshakeEvent.h"

#include "core/NodeEvent.h"
#include "net/ConnectionEvent.h"
#include "core/BundleCore.h"
#include "core/BundleEvent.h"

#include <ibrdtn/data/AgeBlock.h>
#include <ibrdtn/data/ScopeControlHopLimitBlock.h>
#include <ibrdtn/utils/Clock.h>

#include <ibrcommon/thread/MutexLock.h>
#include <ibrcommon/thread/RWLock.h>
#include <ibrcommon/Logger.h>

namespace dtn
{
        namespace routing
        {
                const std::string NodeHandshakeExtension::TAG = "NodeHandshakeExtension";

                NodeHandshakeExtension::NodeHandshakeExtension()
                 : _endpoint(*this)
                {
                }

                NodeHandshakeExtension::~NodeHandshakeExtension()
                {
                }

                void NodeHandshakeExtension::requestHandshake(const dtn::data::EID&, NodeHandshake &request) const
                {
                        request.addRequest(BloomFilterPurgeVector::identifier);
                }

                void NodeHandshakeExtension::responseHandshake(const dtn::data::EID&, const NodeHandshake &request, NodeHandshake &answer)
                {
                        if (request.hasRequest(BloomFilterSummaryVector::identifier))
                        {
                                // add own summary vector to the message
                                const dtn::data::BundleSet vec = (**this).getKnownBundles();

                                // create an item
                                BloomFilterSummaryVector *item = new BloomFilterSummaryVector(vec);

                                // add it to the handshake
                                answer.addItem(item);
                        }

                        if (request.hasRequest(BloomFilterPurgeVector::identifier))
                        {
                                // add own purge vector to the message
                                const dtn::data::BundleSet vec = (**this).getPurgedBundles();

                                // create an item
                                BloomFilterPurgeVector *item = new BloomFilterPurgeVector(vec);

                                // add it to the handshake
                                answer.addItem(item);
                        }
                }

                void NodeHandshakeExtension::processHandshake(const dtn::data::EID &source, NodeHandshake &answer)
                {
                        try {
                                const BloomFilterSummaryVector bfsv = answer.get<BloomFilterSummaryVector>();

                                IBRCOMMON_LOGGER_DEBUG_TAG(NodeHandshakeExtension::TAG, 10) << "summary vector received from " << source.getString() << IBRCOMMON_LOGGER_ENDL;

                                // get the summary vector (bloomfilter) of this ECM
                                const ibrcommon::BloomFilter &filter = bfsv.getVector().getBloomFilter();

                                NeighborDatabase &db = (**this).getNeighborDB();
                                ibrcommon::MutexLock l(db);
                                db.create(source.getNode()).update(filter, answer.getLifetime());
                        } catch (std::exception&) { };

                        try {
                                const BloomFilterPurgeVector bfpv = answer.get<BloomFilterPurgeVector>();

                                IBRCOMMON_LOGGER_DEBUG_TAG(NodeHandshakeExtension::TAG, 10) << "purge vector received from " << source.getString() << IBRCOMMON_LOGGER_ENDL;

                                // get the purge vector (bloomfilter) of this ECM
                                const ibrcommon::BloomFilter &purge = bfpv.getVector().getBloomFilter();

                                // get a reference to the storage
                                dtn::storage::BundleStorage &storage = (**this).getStorage();

                                // create a bundle filter which selects bundles contained in the received
                                // purge vector but not addressed locally
                                class BundleFilter : public dtn::storage::BundleSelector
                                {
                                public:
                                        BundleFilter(const ibrcommon::BloomFilter &filter)
                                         : _filter(filter)
                                        {};

                                        virtual ~BundleFilter() {};

                                        virtual dtn::data::Size limit() const throw () { return 100; };

                                        virtual bool shouldAdd(const dtn::data::MetaBundle &meta) const throw (dtn::storage::BundleSelectorException)
                                        {
                                                // do not select locally addressed bundles
                                                if (meta.destination.getNode() == dtn::core::BundleCore::local)
                                                        return false;

                                                // do not purge non-singleton bundles
                                                if (meta.get(dtn::data::PrimaryBlock::DESTINATION_IS_SINGLETON))
                                                        return false;

                                                // select the bundle if it is in the filter
                                                return _filter.contains(meta.toString());
                                        };

                                        const ibrcommon::BloomFilter &_filter;
                                } bundle_filter(purge);

                                dtn::storage::BundleResultList list;

                                // while we are getting more results from the storage
                                do {
                                        // delete all previous results
                                        list.clear();

                                        // query for more bundles
                                        storage.get(bundle_filter, list);

                                        for (dtn::storage::BundleResultList::const_iterator iter = list.begin(); iter != list.end(); ++iter)
                                        {
                                                const dtn::data::MetaBundle &meta = (*iter);

                                                // delete bundle from storage
                                                storage.remove(meta);

                                                // log the purged bundle
                                                IBRCOMMON_LOGGER_DEBUG_TAG(NodeHandshakeExtension::TAG, 10) << "bundle purged: " << meta.toString() << IBRCOMMON_LOGGER_ENDL;

                                                // gen a report
                                                dtn::core::BundleEvent::raise(meta, dtn::core::BUNDLE_DELETED, StatusReportBlock::NO_ADDITIONAL_INFORMATION);

                                                // add this bundle to the own purge vector
                                                (**this).setPurged(meta);
                                        }
                                } while (!list.empty());
                        } catch (std::exception&) { };
                }

                void NodeHandshakeExtension::doHandshake(const dtn::data::EID &eid)
                {
                        _endpoint.query(eid);
                }

                void NodeHandshakeExtension::notify(const dtn::core::Event *evt) throw ()
                {
                        // If a new neighbor comes available, send him a request for the summary vector
                        // If a neighbor went away we can free the stored summary vector
                        try {
                                const dtn::core::NodeEvent &nodeevent = dynamic_cast<const dtn::core::NodeEvent&>(*evt);
                                const dtn::core::Node &n = nodeevent.getNode();

                                if (nodeevent.getAction() == NODE_UNAVAILABLE)
                                {
                                        // remove the item from the blacklist
                                        _endpoint.removeFromBlacklist(n.getEID());
                                }

                                return;
                        } catch (const std::bad_cast&) { };
                }

                NodeHandshakeExtension::HandshakeEndpoint::HandshakeEndpoint(NodeHandshakeExtension &callback)
                 : _callback(callback)
                {
                        AbstractWorker::initialize("/routing", 50, true);
                }

                NodeHandshakeExtension::HandshakeEndpoint::~HandshakeEndpoint()
                {
                }

                void NodeHandshakeExtension::HandshakeEndpoint::callbackBundleReceived(const Bundle &b)
                {
                        _callback.processHandshake(b);
                }

                void NodeHandshakeExtension::HandshakeEndpoint::send(const dtn::data::Bundle &b)
                {
                        transmit(b);
                }

                void NodeHandshakeExtension::HandshakeEndpoint::removeFromBlacklist(const dtn::data::EID &eid)
                {
                        ibrcommon::MutexLock l(_blacklist_lock);
                        _blacklist.erase(eid);
                }

                void NodeHandshakeExtension::HandshakeEndpoint::query(const dtn::data::EID &origin)
                {
                        {
                                ibrcommon::MutexLock l(_blacklist_lock);
                                // only query once each 60 seconds
                                if (_blacklist[origin] > dtn::utils::Clock::getUnixTimestamp()) return;
                                _blacklist[origin] = dtn::utils::Clock::getUnixTimestamp() + 60;
                        }

                        // create a new request for the summary vector of the neighbor
                        NodeHandshake request(NodeHandshake::HANDSHAKE_REQUEST);

                        // walk through all extensions to generate a request
                        (*_callback).requestHandshake(origin, request);

                        IBRCOMMON_LOGGER_DEBUG_TAG(NodeHandshakeExtension::TAG, 15) << "handshake query from " << origin.getString() << ": " << request.toString() << IBRCOMMON_LOGGER_ENDL;

                        // create a new bundle
                        dtn::data::Bundle req;

                        // set the source of the bundle
                        req.source = getWorkerURI();

                        // set the destination of the bundle
                        req.set(dtn::data::PrimaryBlock::DESTINATION_IS_SINGLETON, true);

                        if (origin.isCompressable())
                                req.destination = origin.add(origin.getDelimiter() + "50");
                        else
                                req.destination = origin.add(origin.getDelimiter() + "routing");

                        // limit the lifetime to 60 seconds
                        req.lifetime = 60;

                        // set high priority
                        req.set(dtn::data::PrimaryBlock::PRIORITY_BIT1, false);
                        req.set(dtn::data::PrimaryBlock::PRIORITY_BIT2, true);

                        dtn::data::PayloadBlock &p = req.push_back<PayloadBlock>();
                        ibrcommon::BLOB::Reference ref = p.getBLOB();

                        // serialize the request into the payload
                        {
                                ibrcommon::BLOB::iostream ios = ref.iostream();
                                (*ios) << request;
                        }

                        // add a schl block
                        dtn::data::ScopeControlHopLimitBlock &schl = req.push_front<dtn::data::ScopeControlHopLimitBlock>();
                        schl.setLimit(1);

                        // add an age block (to prevent expiring due to wrong clocks)
                        req.push_front<dtn::data::AgeBlock>();

                        // send the bundle
                        transmit(req);
                }

                void NodeHandshakeExtension::processHandshake(const dtn::data::Bundle &bundle)
                {
                        // read the ecm
                        const dtn::data::PayloadBlock &p = bundle.find<dtn::data::PayloadBlock>();
                        ibrcommon::BLOB::Reference ref = p.getBLOB();
                        NodeHandshake handshake;

                        // locked within this region
                        {
                                ibrcommon::BLOB::iostream s = ref.iostream();
                                (*s) >> handshake;
                        }

                        IBRCOMMON_LOGGER_DEBUG_TAG(NodeHandshakeExtension::TAG, 15) << "handshake received from " << bundle.source.getString() << ": " << handshake.toString() << IBRCOMMON_LOGGER_ENDL;

                        // if this is a request answer with an summary vector
                        if (handshake.getType() == NodeHandshake::HANDSHAKE_REQUEST)
                        {
                                // create a new request for the summary vector of the neighbor
                                NodeHandshake response(NodeHandshake::HANDSHAKE_RESPONSE);

                                // lock the extension list during the processing
                                (**this).responseHandshake(bundle.source, handshake, response);

                                IBRCOMMON_LOGGER_DEBUG_TAG(NodeHandshakeExtension::TAG, 15) << "handshake reply to " << bundle.source.getString() << ": " << response.toString() << IBRCOMMON_LOGGER_ENDL;

                                // create a new bundle
                                dtn::data::Bundle answer;

                                // set the source of the bundle
                                answer.source = _endpoint.getWorkerURI();

                                // set the destination of the bundle
                                answer.set(dtn::data::PrimaryBlock::DESTINATION_IS_SINGLETON, true);
                                answer.destination = bundle.source;

                                // limit the lifetime to 60 seconds
                                answer.lifetime = 60;

                                // set high priority
                                answer.set(dtn::data::PrimaryBlock::PRIORITY_BIT1, false);
                                answer.set(dtn::data::PrimaryBlock::PRIORITY_BIT2, true);

                                dtn::data::PayloadBlock &p = answer.push_back<PayloadBlock>();
                                ibrcommon::BLOB::Reference ref = p.getBLOB();

                                // serialize the request into the payload
                                {
                                        ibrcommon::BLOB::iostream ios = ref.iostream();
                                        (*ios) << response;
                                }

                                // add a schl block
                                dtn::data::ScopeControlHopLimitBlock &schl = answer.push_front<dtn::data::ScopeControlHopLimitBlock>();
                                schl.setLimit(1);

                                // add an age block (to prevent expiring due to wrong clocks)
                                answer.push_front<dtn::data::AgeBlock>();

                                // transfer the bundle to the neighbor
                                _endpoint.send(answer);

                                // call handshake completed event
                                NodeHandshakeEvent::raiseEvent( NodeHandshakeEvent::HANDSHAKE_REPLIED, bundle.source.getNode() );
                        }
                        else if (handshake.getType() == NodeHandshake::HANDSHAKE_RESPONSE)
                        {
                                // walk through all extensions to process the contents of the response
                                (**this).processHandshake(bundle.source, handshake);

                                // call handshake completed event
                                NodeHandshakeEvent::raiseEvent( NodeHandshakeEvent::HANDSHAKE_COMPLETED, bundle.source.getNode() );
                        }
                }
        } /* namespace routing */
} /* namespace dtn */