dtninbox.cpp

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/*
 * dtninbox.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 "config.h"
#include "ibrdtn/api/Client.h"
#include "ibrcommon/net/socket.h"
#include "ibrcommon/thread/Mutex.h"
#include "ibrcommon/thread/MutexLock.h"
#include "ibrdtn/data/PayloadBlock.h"
#include "ibrdtn/data/Bundle.h"
#include "ibrcommon/data/BLOB.h"
#include "ibrcommon/data/File.h"
#include "ibrcommon/appstreambuf.h"

#include <stdlib.h>
#include <iostream>
#include <map>
#include <vector>
#include <csignal>
#include <sys/types.h>
#include <unistd.h>

using namespace ibrcommon;

void print_help()
{
        cout << "-- dtninbox (IBR-DTN) --" << endl;
        cout << "Syntax: dtninbox [options] <name> <inbox>"  << endl;
        cout << " <name>           the application name" << endl;
        cout << " <inbox>          directory where incoming files should be placed" << endl;
        cout << "* optional parameters *" << endl;
        cout << " -h|--help        display this text" << endl;
        cout << " -w|--workdir     temporary work directory" << endl;
}

map<string,string> readconfiguration(int argc, char** argv)
{
    // print help if not enough parameters are set
    if (argc < 3) { print_help(); exit(0); }

    map<string,string> ret;

    ret["name"] = argv[argc - 2];
    ret["inbox"] = argv[argc - 1];

    for (int i = 0; i < (argc - 2); ++i)
    {
        string arg = argv[i];

        // print help if requested
        if (arg == "-h" || arg == "--help")
        {
            print_help();
            exit(0);
        }

        if ((arg == "-w" || arg == "--workdir") && (argc > i))
        {
            ret["workdir"] = argv[i + 1];
        }
    }

    return ret;
}

// set this variable to false to stop the app
bool _running = true;

// global connection
ibrcommon::socketstream *_conn = NULL;

void term(int signal)
{
    if (signal >= 1)
    {
        _running = false;
        if (_conn != NULL) _conn->close();
    }
}

/*
 * main application method
 */
int main(int argc, char** argv)
{
    // catch process signals
    signal(SIGINT, term);
    signal(SIGTERM, term);

    // read the configuration
    map<string,string> conf = readconfiguration(argc, argv);

    // init working directory
    if (conf.find("workdir") != conf.end())
    {
        ibrcommon::File blob_path(conf["workdir"]);

        if (blob_path.exists())
        {
                ibrcommon::BLOB::changeProvider(new ibrcommon::FileBLOBProvider(blob_path), true);
        }
    }

    // backoff for reconnect
    unsigned int backoff = 2;

    // check outbox for files
        File outbox(conf["outbox"]);

    // loop, if no stop if requested
    while (_running)
    {
        try {
                // Create a stream to the server using TCP.
                ibrcommon::vaddress addr("localhost", 4550);
                ibrcommon::socketstream conn(new ibrcommon::tcpsocket(addr));

                // set the connection globally
                _conn = &conn;

            // Initiate a client for synchronous receiving
            dtn::api::Client client(conf["name"], conn);

            // Connect to the server. Actually, this function initiate the
            // stream protocol by starting the thread and sending the contact header.
            client.connect();

            // reset backoff if connected
            backoff = 2;

            // check the connection
            while (_running)
            {
                // receive the bundle
                dtn::data::Bundle b = client.getBundle();

                // get the reference to the blob
                ibrcommon::BLOB::Reference ref = b.find<dtn::data::PayloadBlock>().getBLOB();

                // create the extract command
                stringstream cmdstream; cmdstream << "tar -x -C " << conf["inbox"];

                // create a tar handler
                appstreambuf extractor(cmdstream.str(), appstreambuf::MODE_WRITE);
                ostream stream(&extractor);

                // write the payload to the extractor
                stream << ref.iostream()->rdbuf();

                // flush the stream
                stream.flush();
            }

            // close the client connection
            client.close();

            // close the connection
            conn.close();

            // set the global connection to NULL
            _conn = NULL;
        } catch (const ibrcommon::socket_exception&) {
                // set the global connection to NULL
                _conn = NULL;

                if (_running)
                {
                                cout << "Connection to bundle daemon failed. Retry in " << backoff << " seconds." << endl;
                                sleep(backoff);

                                // if backoff < 10 minutes
                                if (backoff < 600)
                                {
                                        // set a new backoff
                                        backoff = backoff * 2;
                                }
                }
        } catch (const ibrcommon::IOException&) {
                // set the global connection to NULL
                _conn = NULL;

                if (_running)
                {
                                cout << "Connection to bundle daemon failed. Retry in " << backoff << " seconds." << endl;
                                sleep(backoff);

                                // if backoff < 10 minutes
                                if (backoff < 600)
                                {
                                        // set a new backoff
                                        backoff = backoff * 2;
                                }
                }
        } catch (const std::exception&) {
                // set the global connection to NULL
                _conn = NULL;
        }
    }

    return (EXIT_SUCCESS);
}