source: source/ariba/utility/transport/rfcomm/rfcomm.cpp@ 6211

#include "rfcomm.hpp"

#include "ariba/utility/transport/asio/asio_io_service.h"
#include "ariba/utility/transport/asio/rfcomm.hpp"
#include "ariba/utility/transport/asio/bluetooth_endpoint.hpp"

#include <boost/asio.hpp>
#include <boost/thread.hpp>
#include <boost/array.hpp>
#include <memory.h>
#include <deque>
#include <cerrno>

namespace ariba {
namespace transport {

use_logging_cpp(rfcomm)

using namespace boost::asio;
using namespace detail;
using namespace std;

using boost::system::error_code;

class link_data {
public:
        uint8_t size_[4];
        size_t size;
        uint8_t* buffer;
};

class link_info {
public:
        link_info(io_service& io ) :
                io(io), up(false), connecting(false), local(), remote(), socket(new bluetooth::rfcomm::socket(io)), connect_retries(0),
                size(0), buffer(NULL), sending(false) {
        }

        ~link_info() {
                delete socket;
        }

        void reinit() {
                delete socket;
                socket = new bluetooth::rfcomm::socket(io);
                up = false;
        }

        io_service& io;

        // state
        bool up;
        bool connecting;
        rfcomm_endpoint local, remote;
        bluetooth::rfcomm::socket* socket;
        int connect_retries;

        // read buffer
        uint8_t size_[4];
        size_t size;
        uint8_t* buffer;

        // send buffer
        bool sending;
        boost::mutex mutex;
        std::deque<link_data> send_buffer;
};

void rfcomm::shutdown(link_info* info) {
        if (info != NULL && info->up) {
                info->up = false;
                info->socket->shutdown( bluetooth::rfcomm::socket::shutdown_both );
        }
}


inline bluetooth::rfcomm::endpoint convert( const rfcomm_endpoint& endpoint ) {
        return bluetooth::rfcomm::endpoint(
                endpoint.mac().bluetooth(), endpoint.channel().value()
        );
}

inline rfcomm_endpoint convert( const bluetooth::rfcomm::endpoint& endpoint ) {
        mac_address mac;
        mac.bluetooth( endpoint.address() );
        rfcomm_channel_address channel;
        channel.value( endpoint.channel() );
        return rfcomm_endpoint( mac, channel );
}


rfcomm::rfcomm(uint16_t channel) :
        channel(channel), io(asio_io_service::alloc()) {
        accept_retries = 0;
}

rfcomm::~rfcomm() {
        asio_io_service::free();
}

void rfcomm::start() {

        // start io service
        asio_io_service::start();

        // create acceptor
        logging_info( "Binding to channel " << channel );
        acceptor = new bluetooth::rfcomm::acceptor(io,
                bluetooth::rfcomm::endpoint(bluetooth::rfcomm::get(), channel )
        );

        send_data = new link_data();

        // start accepting
        start_accept();
}

void rfcomm::stop() {
        logging_info( "Stopping asio rfcomm" );
}

void rfcomm::send(const address_v* remote, const uint8_t* data, size_t size) {

        // get end-point
        rfcomm_endpoint endpoint = *remote;
        endpoint = convert(convert(endpoint));

        // try to find established connector
        logging_debug("Trying to find a already existing link.");
        link_info* info = NULL;
        for (size_t i = 0; i < links.size(); i++)
                if (links[i]->remote.mac() == endpoint.mac()) {
                        logging_debug("Using already established link");
                        info = links[i];
                        break;
                }

        // not found, or not up? ->try to (re-)connect
        if (info==NULL || ((!info->up || !info->socket->is_open()) && !info->connecting) ) {
                logging_debug( "Connecting to " << endpoint.to_string() );
                if (info != NULL && (!info->up || !info->socket->is_open())) {
                        logging_error("Old link is down. Trying to re-establish link.");
                        info->reinit();
                } else {
                        info = new link_info(io);
                }
                info->connect_retries = 0;
                info->remote = endpoint;
                info->connecting = true;
                info->socket->async_connect( convert(endpoint), boost::bind(
                        &rfcomm::handle_connect, this,
                        boost::asio::placeholders::error, info
                ));
                links.push_back(info);
        }

        // copy message
        link_data ldata;
        ldata.size = size;
        ldata.size_[0] = (size >> 24) & 0xFF;
        ldata.size_[1] = (size >> 16) & 0xFF;
        ldata.size_[2] = (size >> 8) & 0xFF;
        ldata.size_[3] = (size >> 0) & 0xFF;
        ldata.buffer = new uint8_t[size];
        memcpy(ldata.buffer, data, size);

        // enqueue message
        info->mutex.lock();
        info->send_buffer.push_back(ldata);
        info->mutex.unlock();

        // start writing
        io.post( boost::bind( &rfcomm::start_write, this, info) );
}

void rfcomm::send(const endpoint_set& endpoints, const uint8_t* data, size_t size) {
        // send a message to each combination of mac-address and channel
        BOOST_FOREACH( const mac_address mac, endpoints.bluetooth ) {
                BOOST_FOREACH( const rfcomm_channel_address channel, endpoints.rfcomm ) {
                        rfcomm_endpoint endpoint(mac, channel);
                        address_vf vf = endpoint;
                        send(vf,data,size);
                }
        }
}

void rfcomm::terminate( const address_v* remote) {
        // get end-point
        rfcomm_endpoint endpoint = *remote;

        for (size_t i = 0; i < links.size(); i++)
                if (links[i]->remote.mac() == endpoint.mac()) {
                        // close socket
                        shutdown(links[i]);
                        break;
                }
}

void rfcomm::register_listener(transport_listener* listener) {
        this->listener = listener;
}

void rfcomm::start_accept() {

        logging_info( "Waiting for connections ..." );

        // start accepting a connection
        link_info* info = new link_info(io);
        acceptor->async_accept(*info->socket, boost::bind(
                // bind parameters
                &rfcomm::handle_accept, this,

                // handler parameters
                boost::asio::placeholders::error, info
        ));
        asio_io_service::start();
}

void rfcomm::handle_accept(const error_code& error, link_info* info) {
        if (error) {
                logging_error( "Error waiting for new connections. Error code: "<< error.message()
                                << ", trying to recover (attempt " << accept_retries << ")");

                // restart accepting
                if (accept_retries<3) {
                        accept_retries++;
                        start_accept();
                } else
                        delete info;

                return;
        }

        links_mutex.lock();

        // convert endpoints
        info->up = true;
        info->local  = convert( info->socket->local_endpoint()  );
        info->remote = convert( info->socket->remote_endpoint() );

        logging_debug("Accepted incoming connection from "
                << info->remote.to_string() );

        // add to list
        links.push_back(info);
        links_mutex.unlock();

        // start i/o
        start_read(info);
        start_write(info);

        // restart accept
        start_accept();
}

void rfcomm::handle_connect( const error_code& error, link_info* info ) {
        if (error) {
                logging_error( "Can not connect. Error code: "
                                << error.message() << " Retrying ... "
                                "(attempt " << info->connect_retries << ")" );

                // do we retry this connection? yes->
                if (info->connect_retries<3) {
                        // increase counter
                        info->connecting = false;
                        info->connect_retries++;
                        info->reinit();

                        // retry connection attempt
                        info->socket->async_connect( convert(info->remote), boost::bind(
                                &rfcomm::handle_connect, this,
                                boost::asio::placeholders::error, info
                        ));

                } else { // no-> delete link and stop
                        return;
                }
        }

        // convert endpoints
        info->up = true;
        info->connecting = false;
        info->local  = convert( info->socket->local_endpoint()  );
        info->remote = convert( info->socket->remote_endpoint() );

        logging_debug( "Connected to " << info->remote.to_string() );

        // add to list
        links_mutex.lock();
        links.push_back(info);
        links_mutex.unlock();

        // start i/o
        start_read(info);
        start_write(info);
}

void rfcomm::start_read(link_info* info) {
        logging_debug("Start reading ...");

        // start read
        boost::asio::async_read(*info->socket,

                // read size of packet
                boost::asio::buffer(info->size_, 4),

                // bind handler
                boost::bind(

                        // bind parameters
                        &rfcomm::handle_read_header, this,

                        // handler parameters
                        placeholders::error, placeholders::bytes_transferred, info
                )
        );
}

void rfcomm::handle_read_header(const error_code& error, size_t bytes,
        link_info* info) {

        // handle error
        if (error) {
                logging_error("Failed to receive message payload. Error code: "
                                << error.message() );
                shutdown(info);
                return;
        }

        // ignore errors and wait for all data to be received
        if (bytes != 4) return;

        // get size
        info->size = (info->size_[0]<<24) + (info->size_[1] << 16) +
                        (info->size_[2]<< 8) + (info->size_[3] << 0);

        // allocate buffer
        info->buffer = new uint8_t[info->size];

        // start read
        boost::asio::async_read(*info->socket,
                // read size of packet
                boost::asio::buffer(info->buffer, info->size),
                // bind handler
                boost::bind(
                        // bind parameters
                        &rfcomm::handle_read_data, this,
                        // handler parameters
                        placeholders::error, placeholders::bytes_transferred, info
                )
        );
}

void rfcomm::handle_read_data(const error_code& error, size_t bytes,
        link_info* info) {

        // check error
        if (error) {
                logging_error("Failed to receive message payload. Error: " << error.message() );
                shutdown(info);
                return;
        }

        // wait for all data to be received
        if (bytes != info->size)
                return;

        // deliver data
        listener->receive_message(this, info->local, info->remote, info->buffer, info->size );

        // free buffers and reset size buffer
        delete [] info->buffer;
        for (size_t i=0; i<4; i++) info->size_[i] = 0;

        start_read(info);
}

void rfcomm::start_write( link_info* info ) {
        // do not start writing if sending is in progress
        if (info->sending || !info->up || info->send_buffer.size()==0) return;

        // set sending flag
        info->sending = true;

        // safely remove data from deque
        *send_data = info->send_buffer.front();
        info->send_buffer.pop_front();

        boost::array<boost::asio::mutable_buffer, 2> buffer;
        buffer[0] = boost::asio::buffer(send_data->size_,4);
        buffer[1] = boost::asio::buffer(send_data->buffer,send_data->size);

        // start writing
        boost::asio::async_write(*info->socket,
                // read size of packet
                buffer,
                // bind handler
                boost::bind(
                        // bind parameters
                        &rfcomm::handle_write_data, this,
                        // handler parameters
                        placeholders::error, placeholders::bytes_transferred,
                        info, send_data->size, send_data->buffer
                )
        );
}

void rfcomm::handle_write_data(const error_code& error, size_t bytes,
        link_info* info, size_t size, uint8_t* buffer ) {

        // handle error
        if (error) {
                logging_error( "Message sent error. Error: " << error.message() );
                info->sending = false;
                shutdown(info);
                return;
        }

        //  wait for all data to be sent
        if (bytes != (size+4) )
                return;

        logging_debug( "Message sent" );

        // free buffer
        delete [] buffer;
        info->sending = false;

        // restart-write
        start_write(info);
}

}} // namespace ariba::transport