FileConvergenceLayer.cpp

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/*
 * FileConvergenceLayer.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 "Configuration.h"
#include "net/FileConvergenceLayer.h"
#include "net/TransferAbortedEvent.h"
#include "net/BundleReceivedEvent.h"
#include "core/EventDispatcher.h"
#include "core/BundleEvent.h"
#include "core/BundleCore.h"
#include "core/NodeEvent.h"
#include "core/TimeEvent.h"
#include "routing/BaseRouter.h"
#include "routing/NodeHandshake.h"
#include <ibrdtn/data/BundleSet.h>
#include <ibrdtn/data/ScopeControlHopLimitBlock.h>
#include <ibrdtn/utils/Clock.h>
#include <ibrcommon/data/File.h>
#include <ibrcommon/Logger.h>
#include <ibrcommon/thread/MutexLock.h>

namespace dtn
{
        namespace net
        {
                FileConvergenceLayer::Task::Task(FileConvergenceLayer::Task::Action a, const dtn::core::Node &n)
                 : action(a), node(n)
                {
                }

                FileConvergenceLayer::Task::~Task()
                {
                }

                FileConvergenceLayer::StoreBundleTask::StoreBundleTask(const dtn::core::Node &n, const dtn::net::BundleTransfer &j)
                 : FileConvergenceLayer::Task(TASK_STORE, n), job(j)
                {
                }

                FileConvergenceLayer::StoreBundleTask::~StoreBundleTask()
                {
                }

                FileConvergenceLayer::FileConvergenceLayer()
                {
                }

                FileConvergenceLayer::~FileConvergenceLayer()
                {
                }

                void FileConvergenceLayer::componentUp() throw ()
                {
                        // routine checked for throw() on 15.02.2013
                        dtn::core::EventDispatcher<dtn::core::NodeEvent>::add(this);
                        dtn::core::EventDispatcher<dtn::core::TimeEvent>::add(this);
                }

                void FileConvergenceLayer::componentDown() throw ()
                {
                        // routine checked for throw() on 15.02.2013
                        dtn::core::EventDispatcher<dtn::core::NodeEvent>::remove(this);
                        dtn::core::EventDispatcher<dtn::core::TimeEvent>::remove(this);
                }

                void FileConvergenceLayer::__cancellation() throw ()
                {
                        _tasks.abort();
                }

                void FileConvergenceLayer::componentRun() throw ()
                {
                        try {
                                while (true)
                                {
                                        Task *t = _tasks.getnpop(true);

                                        try {
                                                switch (t->action)
                                                {
                                                        case Task::TASK_LOAD:
                                                        {
                                                                // load bundles (receive)
                                                                load(t->node);
                                                                break;
                                                        }

                                                        case Task::TASK_STORE:
                                                        {
                                                                try {
                                                                        StoreBundleTask &sbt = dynamic_cast<StoreBundleTask&>(*t);
                                                                        dtn::storage::BundleStorage &storage = dtn::core::BundleCore::getInstance().getStorage();

                                                                        // get the file path of the node
                                                                        ibrcommon::File path = getPath(sbt.node);

                                                                        // scan for bundles
                                                                        std::list<dtn::data::MetaBundle> bundles = scan(path);

                                                                        try {
                                                                                // check if bundle is a routing bundle
                                                                                if (sbt.job.getBundle().source == dtn::core::BundleCore::local.add("/routing"))
                                                                                {
                                                                                        // read the bundle out of the storage
                                                                                        const dtn::data::Bundle bundle = storage.get(sbt.job.getBundle());

                                                                                        if (bundle.destination == sbt.node.getEID().add("/routing"))
                                                                                        {
                                                                                                // add this bundle to the blacklist
                                                                                                {
                                                                                                        ibrcommon::MutexLock l(_blacklist_mutex);
                                                                                                        if (_blacklist.find(bundle) != _blacklist.end())
                                                                                                        {
                                                                                                                // send transfer aborted event
                                                                                                                sbt.job.abort(dtn::net::TransferAbortedEvent::REASON_REFUSED);
                                                                                                                continue;
                                                                                                        }
                                                                                                        _blacklist.add(bundle);
                                                                                                }

                                                                                                // create ECM reply
                                                                                                replyHandshake(bundle, bundles);

                                                                                                // raise bundle event
                                                                                                sbt.job.complete();
                                                                                                continue;
                                                                                        }
                                                                                }

                                                                                // check if bundle is already in the path
                                                                                for (std::list<dtn::data::MetaBundle>::const_iterator iter = bundles.begin(); iter != bundles.end(); ++iter)
                                                                                {
                                                                                        if ((*iter) == sbt.job.getBundle())
                                                                                        {
                                                                                                // send transfer aborted event
                                                                                                sbt.job.abort(dtn::net::TransferAbortedEvent::REASON_REFUSED);
                                                                                                continue;
                                                                                        }
                                                                                }

                                                                                ibrcommon::TemporaryFile filename(path, "bundle");

                                                                                try {
                                                                                        // read the bundle out of the storage
                                                                                        const dtn::data::Bundle bundle = storage.get(sbt.job.getBundle());

                                                                                        std::fstream fs(filename.getPath().c_str(), std::fstream::out);

                                                                                        IBRCOMMON_LOGGER_TAG("FileConvergenceLayer", info) << "write bundle " << sbt.job.getBundle().toString() << " to file " << filename.getPath() << IBRCOMMON_LOGGER_ENDL;

                                                                                        dtn::data::DefaultSerializer s(fs);

                                                                                        // serialize the bundle
                                                                                        s << bundle;

                                                                                        // raise bundle event
                                                                                        sbt.job.complete();
                                                                                } catch (const ibrcommon::Exception&) {
                                                                                        filename.remove();
                                                                                        throw;
                                                                                }
                                                                        } catch (const dtn::storage::NoBundleFoundException&) {
                                                                                // send transfer aborted event
                                                                                sbt.job.abort(dtn::net::TransferAbortedEvent::REASON_BUNDLE_DELETED);
                                                                        } catch (const ibrcommon::Exception&) {
                                                                                // something went wrong - requeue transfer for later
                                                                        }

                                                                } catch (const std::bad_cast&) { }
                                                                break;
                                                        }
                                                }
                                        } catch (const std::exception &ex) {
                                                IBRCOMMON_LOGGER_TAG("FileConvergenceLayer", error) << "error while processing file convergencelayer task: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                        }
                                        delete t;
                                }
                        } catch (const ibrcommon::QueueUnblockedException &ex) { };
                }

                void FileConvergenceLayer::raiseEvent(const dtn::core::Event *evt) throw ()
                {
                        try {
                                const dtn::core::NodeEvent &node = dynamic_cast<const dtn::core::NodeEvent&>(*evt);

                                if (node.getAction() == dtn::core::NODE_AVAILABLE)
                                {
                                        const dtn::core::Node &n = node.getNode();
                                        if ( n.has(dtn::core::Node::CONN_FILE) )
                                        {
                                                _tasks.push(new Task(Task::TASK_LOAD, n));
                                        }
                                }
                        } catch (const std::bad_cast&) { };

                        try {
                                const dtn::core::TimeEvent &time = dynamic_cast<const dtn::core::TimeEvent&>(*evt);

                                if (time.getAction() == dtn::core::TIME_SECOND_TICK)
                                {
                                        ibrcommon::MutexLock l(_blacklist_mutex);
                                        _blacklist.expire(time.getTimestamp());
                                }
                        } catch (const std::bad_cast&) { };
                }

                const std::string FileConvergenceLayer::getName() const
                {
                        return "FileConvergenceLayer";
                }

                dtn::core::Node::Protocol FileConvergenceLayer::getDiscoveryProtocol() const
                {
                        return dtn::core::Node::CONN_FILE;
                }

                void FileConvergenceLayer::open(const dtn::core::Node&)
                {
                }

                void FileConvergenceLayer::load(const dtn::core::Node &n)
                {
                        std::list<dtn::data::MetaBundle> ret;
                        std::list<ibrcommon::File> files;

                        // list all files in the folder
                        getPath(n).getFiles(files);

                        // get a reference to the router
                        dtn::routing::BaseRouter &router = dtn::core::BundleCore::getInstance().getRouter();

                        for (std::list<ibrcommon::File>::const_iterator iter = files.begin(); iter != files.end(); ++iter)
                        {
                                const ibrcommon::File &f = (*iter);

                                // skip system files
                                if (f.isSystem()) continue;

                                try {
                                        // open the file
                                        std::fstream fs(f.getPath().c_str(), std::fstream::in);

                                        // get a deserializer
                                        dtn::data::DefaultDeserializer d(fs);

                                        dtn::data::MetaBundle bundle;

                                        // load meta data
                                        d >> bundle;

                                        // check the bundle
                                        if ( ( bundle.destination == EID() ) || ( bundle.source == EID() ) )
                                        {
                                                // invalid bundle!
                                                throw dtn::data::Validator::RejectedException("destination or source EID is null");
                                        }

                                        // ask if the bundle is already known
                                        if ( router.isKnown(bundle) ) continue;
                                } catch (const std::exception&) {
                                        // bundle could not be read
                                        continue;
                                }

                                try {
                                        // open the file
                                        std::fstream fs(f.getPath().c_str(), std::fstream::in);

                                        // get a deserializer
                                        dtn::data::DefaultDeserializer d(fs, dtn::core::BundleCore::getInstance());

                                        dtn::data::Bundle bundle;

                                        // load meta data
                                        d >> bundle;

                                        // raise default bundle received event
                                        dtn::net::BundleReceivedEvent::raise(n.getEID(), bundle, false);
                                }
                                catch (const dtn::data::Validator::RejectedException &ex)
                                {
                                        // display the rejection
                                        IBRCOMMON_LOGGER_TAG("FileConvergenceLayer", warning) << "bundle has been rejected: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                }
                                catch (const dtn::InvalidDataException &ex) {
                                        // display the rejection
                                        IBRCOMMON_LOGGER_TAG("FileConvergenceLayer", warning) << "invalid bundle-data received: " << ex.what() << IBRCOMMON_LOGGER_ENDL;
                                }
                        }
                }

                ibrcommon::File FileConvergenceLayer::getPath(const dtn::core::Node &n)
                {
                        std::list<dtn::core::Node::URI> uris = n.get(dtn::core::Node::CONN_FILE);

                        // abort the transfer, if no URI exists
                        if (uris.empty()) throw ibrcommon::Exception("path not defined");

                        // get the URI of the file path
                        const std::string &uri = uris.front().value;

                        if (uri.substr(0, 7) != "file://") throw ibrcommon::Exception("path invalid");

                        return ibrcommon::File(uri.substr(7, uri.length() - 7));
                }

                std::list<dtn::data::MetaBundle> FileConvergenceLayer::scan(const ibrcommon::File &path)
                {
                        std::list<dtn::data::MetaBundle> ret;
                        std::list<ibrcommon::File> files;

                        // list all files in the folder
                        path.getFiles(files);

                        for (std::list<ibrcommon::File>::const_iterator iter = files.begin(); iter != files.end(); ++iter)
                        {
                                const ibrcommon::File &f = (*iter);

                                // skip system files
                                if (f.isSystem()) continue;

                                try {
                                        // open the file
                                        std::fstream fs(f.getPath().c_str(), std::fstream::in);

                                        // get a deserializer
                                        dtn::data::DefaultDeserializer d(fs);

                                        dtn::data::MetaBundle meta;

                                        // load meta data
                                        d >> meta;

                                        if (meta.expiretime < dtn::utils::Clock::getTime())
                                        {
                                                dtn::core::BundleEvent::raise(meta, dtn::core::BUNDLE_DELETED, dtn::data::StatusReportBlock::LIFETIME_EXPIRED);
                                                throw ibrcommon::Exception("bundle is expired");
                                        }

                                        // put the meta bundle in the list
                                        ret.push_back(meta);
                                } catch (const std::exception&) {
                                        IBRCOMMON_LOGGER_DEBUG_TAG("FileConvergenceLayer", 34) << "bundle in file " << f.getPath() << " invalid or expired" << IBRCOMMON_LOGGER_ENDL;

                                        // delete the file
                                        ibrcommon::File(f).remove();
                                }
                        }

                        return ret;
                }

                void FileConvergenceLayer::queue(const dtn::core::Node &n, const dtn::net::BundleTransfer &job)
                {
                        _tasks.push(new StoreBundleTask(n, job));
                }

                void FileConvergenceLayer::replyHandshake(const dtn::data::Bundle &bundle, std::list<dtn::data::MetaBundle> &bl)
                {
                        // read the ecm
                        const dtn::data::PayloadBlock &p = bundle.find<dtn::data::PayloadBlock>();
                        ibrcommon::BLOB::Reference ref = p.getBLOB();
                        dtn::routing::NodeHandshake request;

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

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

                                if (request.hasRequest(dtn::routing::BloomFilterSummaryVector::identifier))
                                {
                                        // add own summary vector to the message
                                        dtn::data::BundleSet vec;

                                        // add bundles in the path
                                        for (std::list<dtn::data::MetaBundle>::const_iterator iter = bl.begin(); iter != bl.end(); ++iter)
                                        {
                                                vec.add(*iter);
                                        }

                                        // add bundles from the blacklist
                                        {
                                                ibrcommon::MutexLock l(_blacklist_mutex);
                                                for (std::set<dtn::data::MetaBundle>::const_iterator iter = _blacklist.begin(); iter != _blacklist.end(); ++iter)
                                                {
                                                        vec.add(*iter);
                                                }
                                        }

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

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

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

                                // set the source of the bundle
                                answer.source = bundle.destination;

                                // 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);

                                // raise default bundle received event
                                dtn::net::BundleReceivedEvent::raise(bundle.destination.getNode(), answer, false);
                        }
                }
        } /* namespace net */
} /* namespace dtn */