LOWPANConvergenceLayer.cpp

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/*
 * LOWPANConnection.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 "net/LOWPANConvergenceLayer.h"
#include "net/LOWPANConnection.h"
#include "net/DiscoveryAgent.h"
#include "core/EventDispatcher.h"
#include "core/BundleCore.h"
#include "core/TimeEvent.h"
#include <ibrcommon/net/lowpanstream.h>
#include <ibrcommon/net/lowpansocket.h>

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

#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <iostream>
#include <list>

#define EXTENDED_MASK   0x08
#define SEQ_NUM_MASK    0x07

using namespace dtn::data;

namespace dtn
{
        namespace net
        {
                const size_t LOWPANConvergenceLayer::BUFF_SIZE = 115;

                LOWPANConvergenceLayer::LOWPANConvergenceLayer(const ibrcommon::vinterface &net, uint16_t panid, unsigned int mtu)
                        : _net(net), _panid(panid), m_maxmsgsize(mtu), _running(false)
                {
                        // convert the panid into a string
                        std::stringstream ss;
                        ss << _panid;

                        // assign the broadcast address
                        _addr_broadcast = ibrcommon::vaddress("0xffff", ss.str(), AF_IEEE802154);
                }

                LOWPANConvergenceLayer::~LOWPANConvergenceLayer()
                {
                        componentDown();
                }

                dtn::core::Node::Protocol LOWPANConvergenceLayer::getDiscoveryProtocol() const
                {
                        return dtn::core::Node::CONN_LOWPAN;
                }

                void LOWPANConvergenceLayer::onUpdateBeacon(const ibrcommon::vinterface &iface, DiscoveryBeacon &announcement) throw(dtn::net::DiscoveryBeaconHandler::NoServiceHereException)
                {
                        if (iface == _net)
                        {
                                stringstream service;

                                struct sockaddr_ieee802154 address;
                                address.addr.addr_type = IEEE802154_ADDR_SHORT;
                                address.addr.pan_id = _panid;

                                // Get address via netlink
                                ibrcommon::lowpansocket::getAddress(&address.addr, iface);

                                //FIXME better naming for address and panid. This will need updates to the service parser.
                                service << "ip=" << address.addr.short_addr << ";port=" << _panid << ";";

                                announcement.addService( DiscoveryService(getDiscoveryProtocol(), service.str()));
                        }
                        else
                        {
                                 throw dtn::net::DiscoveryBeaconHandler::NoServiceHereException();
                        }
                }

                void LOWPANConvergenceLayer::send_cb(const char *buf, const size_t len, const ibrcommon::vaddress &addr)
                {
                        ibrcommon::socketset socks = _vsocket.getAll();
                        if (socks.size() == 0) return;
                        ibrcommon::lowpansocket &sock = dynamic_cast<ibrcommon::lowpansocket&>(**socks.begin());

                        // set write lock
                        ibrcommon::MutexLock l(m_writelock);

                        if (_addr_broadcast == addr) {
                                // disable auto-ack feature for broadcast
                                sock.setAutoAck(false);

                                // send converted line
                                sock.sendto(buf, len, 0, _addr_broadcast);

                                // re-enable auto-ack feature
                                sock.setAutoAck(true);
                        } else {
                                // send converted line
                                sock.sendto(buf, len, 0, addr);
                        }
                }

                void LOWPANConvergenceLayer::queue(const dtn::core::Node &node, const dtn::net::BundleTransfer &job)
                {
                        const std::list<dtn::core::Node::URI> uri_list = node.get(dtn::core::Node::CONN_LOWPAN);
                        if (uri_list.empty()) return;

                        const dtn::core::Node::URI &uri = uri_list.front();

                        std::string address;
                        unsigned int pan;

                        uri.decode(address, pan);

                        std::stringstream ss_pan; ss_pan << pan;

                        ibrcommon::vaddress addr( address, ss_pan.str(), AF_IEEE802154 );

                        IBRCOMMON_LOGGER_DEBUG_TAG("LOWPANConvergenceLayer", 55) << "LOWPANConvergenceLayer::queue"<< IBRCOMMON_LOGGER_ENDL;

                        ibrcommon::MutexLock lc(_connection_lock);
                        LOWPANConnection *connection = getConnection(addr);
                        connection->_sender.queue(job);
                }

                LOWPANConnection* LOWPANConvergenceLayer::getConnection(const ibrcommon::vaddress &addr)
                {
                        // Test if connection for this address already exist
                        for(std::list<LOWPANConnection*>::iterator i = ConnectionList.begin(); i != ConnectionList.end(); ++i)
                        {
                                LOWPANConnection &conn = dynamic_cast<LOWPANConnection&>(**i);

                                IBRCOMMON_LOGGER_DEBUG_TAG("LOWPANConvergenceLayer", 55) << "Connection address: " << conn._address.toString() << IBRCOMMON_LOGGER_ENDL;

                                if (conn._address == addr)
                                        return (*i);
                        }

                        // Connection does not exist, create one and put it into the list
                        LOWPANConnection *connection = new LOWPANConnection(addr, (*this));

                        ConnectionList.push_back(connection);
                        IBRCOMMON_LOGGER_DEBUG_TAG("LOWPANConvergenceLayer", 55) << "LOWPANConvergenceLayer::getConnection "<< connection->_address.toString() << IBRCOMMON_LOGGER_ENDL;
                        connection->start();
                        return connection;
                }

                void LOWPANConvergenceLayer::remove(const LOWPANConnection *conn)
                {
                        ibrcommon::MutexLock lc(_connection_lock);

                        std::list<LOWPANConnection*>::iterator i;
                        for(i = ConnectionList.begin(); i != ConnectionList.end(); ++i)
                        {
                                if ((*i) == conn)
                                {
                                        ConnectionList.erase(i);
                                        return;
                                }
                        }
                }

                void LOWPANConvergenceLayer::componentUp() throw ()
                {
                        try {
                                _vsocket.add(new ibrcommon::lowpansocket(_panid, _net));
                                _vsocket.up();

                                dtn::net::DiscoveryAgent &agent = dtn::core::BundleCore::getInstance().getDiscoveryAgent();
                                agent.registerService(_net, this);
                        } catch (const ibrcommon::socket_exception &ex) {
                                IBRCOMMON_LOGGER_TAG("LOWPANConvergenceLayer", error) << "bind to " << _net.toString() << ":" << _panid << " failed (" << ex.what() << ")" << IBRCOMMON_LOGGER_ENDL;
                        }
                        
                        // set component in running mode
                        _running = true;
                }

                void LOWPANConvergenceLayer::componentDown() throw ()
                {
                        dtn::net::DiscoveryAgent &agent = dtn::core::BundleCore::getInstance().getDiscoveryAgent();
                        agent.unregisterService(_net, this);

                        _vsocket.destroy();
                        stop();
                        join();
                }

                void LOWPANConvergenceLayer::onAdvertiseBeacon(const ibrcommon::vinterface &iface, const DiscoveryBeacon &beacon) throw ()
                {
                        if (_net != iface) return;

                        IBRCOMMON_LOGGER_DEBUG_TAG("LOWPANConvergenceLayer", 60) << "LOWPAN IPND beacon send started" << IBRCOMMON_LOGGER_ENDL;

                        std::vector<char> ipnd_buf(BUFF_SIZE);

                        // Set extended header bit. Everything else 0
                        ipnd_buf[0] = 0x08;
                        // Set discovery bit in extended header
                        ipnd_buf[1] = (char)0x80;

                        // serialize announcement
                        stringstream ss;
                        ss << beacon;

                        dtn::data::Length len = ss.str().size();
                        if (len > 113)
                                IBRCOMMON_LOGGER_TAG("LOWPANConvergenceLayer", error) << "Discovery announcement to big (" << len << ")" << IBRCOMMON_LOGGER_ENDL;

                        // copy data infront of the 2 byte header
                        memcpy(&ipnd_buf[2], ss.str().c_str(), len);

                        // send out broadcast frame
                        send_cb(&ipnd_buf[0], len + 2, _addr_broadcast);
                }

                void LOWPANConvergenceLayer::componentRun() throw ()
                {
                        dtn::net::DiscoveryAgent &agent = dtn::core::BundleCore::getInstance().getDiscoveryAgent();

                        while (_running)
                        {
                                try {
                                        ibrcommon::socketset readfds;
                                        _vsocket.select(&readfds, NULL, NULL, NULL);

                                        for (ibrcommon::socketset::iterator iter = readfds.begin(); iter != readfds.end(); ++iter) {
                                                ibrcommon::lowpansocket &sock = dynamic_cast<ibrcommon::lowpansocket&>(**iter);

                                                std::vector<char> data(m_maxmsgsize);
                                                char header;

                                                // place to store the peer address
                                                ibrcommon::vaddress peeraddr;

                                                // Receive full frame from socket
                                                ssize_t len = sock.recvfrom(&data[0], static_cast<size_t>(m_maxmsgsize), 0, peeraddr);

                                                IBRCOMMON_LOGGER_DEBUG_TAG("LOWPANConvergenceLayer", 40) << "Received IEEE 802.15.4 frame from " << peeraddr.toString() << IBRCOMMON_LOGGER_ENDL;

                                                // We got nothing from the socket, keep reading
                                                if (len <= 0)
                                                        continue;

                                                // Retrieve header of frame
                                                header = data[0];

                                                // Check for extended header and retrieve if available
                                                if ((header & EXTENDED_MASK) && (data[1] & 0x80)) {
                                                        DiscoveryBeacon beacon = agent.obtainBeacon();
                                                        stringstream ss;
                                                        ss.write(&data[2], len-2);
                                                        ss >> beacon;

                                                        // ignore own beacons
                                                        if (beacon.getEID() == dtn::core::BundleCore::local) continue;

                                                        // do not accept short beacons
                                                        if (!beacon.isShort())
                                                        {
                                                                agent.onBeaconReceived(beacon);
                                                        }

                                                        continue;
                                                }

                                                ibrcommon::MutexLock lc(_connection_lock);

                                                // Connection instance for this address
                                                LOWPANConnection* connection = getConnection(peeraddr);

                                                // Decide in which queue to write based on the src address
                                                connection->getStream().queue(&data[0], len);
                                        }
                                } catch (const ibrcommon::socket_exception&) {
                                        return;
                                }

                                yield();
                        }
                }

                void LOWPANConvergenceLayer::__cancellation() throw ()
                {
                        _running = false;
                        _vsocket.down();
                }

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