iridium_shore_sbd_directip.h

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// Copyright 2015-2026:
//   GobySoft, LLC (2013-)
//   Community contributors (see AUTHORS file)
// File authors:
//   Toby Schneider <toby@gobysoft.org>
//
//
// This file is part of the Goby Underwater Autonomy Project Libraries
// ("The Goby Libraries").
//
// The Goby Libraries are free software: you can redistribute them and/or modify
// them under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 2.1 of the License, or
// (at your option) any later version.
//
// The Goby Libraries are distributed in the hope that they will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with Goby.  If not, see <http://www.gnu.org/licenses/>.
 
#ifndef GOBY_ACOMMS_MODEMDRIVER_IRIDIUM_SHORE_SBD_DIRECTIP_H
#define GOBY_ACOMMS_MODEMDRIVER_IRIDIUM_SHORE_SBD_DIRECTIP_H
 
#include <boost/asio.hpp>
#include <boost/bind/bind.hpp>
#include <boost/enable_shared_from_this.hpp>
 
#include "goby/acomms/protobuf/iridium_sbd_directip.pb.h"
#include "goby/acomms/protobuf/rudics_shore.pb.h"
#include "goby/time.h"
#include "goby/util/asio_compat.h"
#include "goby/util/binary.h"
#include "goby/util/debug_logger.h"
 
namespace goby
{
namespace acomms
{
namespace directip
{
 
class SBDMessageReader
{
  public:
    SBDMessageReader(boost::asio::ip::tcp::socket& socket)
        : socket_(socket), pos_(0), data_(1 << 16)
    {
    }
 
    virtual bool data_ready() const = 0;
 
    const goby::acomms::iridium::protobuf::DirectIPMOPreHeader& pre_header() const
    {
        return pre_header_;
    }
    const goby::acomms::iridium::protobuf::DirectIPMOHeader& header() const { return header_; }
    const goby::acomms::iridium::protobuf::DirectIPMOPayload& body() const { return body_; }
    const goby::acomms::iridium::protobuf::DirectIPMTConfirmation& confirm() const
    {
        return confirm_;
    }
 
    enum
    {
        PRE_HEADER_SIZE = 3,
        BITS_PER_BYTE = 8
    };
 
    void pre_header_handler(const boost::system::error_code& error, std::size_t bytes_transferred)
    {
        if (error)
            throw std::runtime_error("Error while reading: " + error.message());
 
        pre_header_.set_protocol_ver(read_byte());
        pre_header_.set_overall_length(read_uint16());
 
        boost::asio::async_read(socket_, boost::asio::buffer(data_),
                                boost::asio::transfer_at_least(pre_header_.overall_length() +
                                                               PRE_HEADER_SIZE - bytes_transferred),
                                boost::bind(&SBDMessageReader::ie_handler, this,
                                            boost::placeholders::_1, boost::placeholders::_2));
    }
 
    std::vector<char>& data() { return data_; }
 
  private:
    void ie_handler(const boost::system::error_code& error, std::size_t bytes_transferred)
    {
        if (error)
            throw std::runtime_error("Error while reading: " + error.message());
 
        char iei = read_byte();
        unsigned length = read_uint16();
 
        switch (iei)
        {
            case 0x01: // header
            {
                header_.set_iei(iei);
                header_.set_length(length);
                header_.set_cdr_reference(read_uint32()); // 4 bytes
 
                header_.set_imei(read_imei()); // 15 bytes
 
                header_.set_session_status(read_byte());    // 1 byte
                header_.set_momsn(read_uint16());           // 2 bytes
                header_.set_mtmsn(read_uint16());           // 2 bytes
                header_.set_time_of_session(read_uint32()); // 4 bytes
            }
            break;
 
            case 0x02: // payload
                body_.set_iei(iei);
                body_.set_length(length);
                body_.set_payload(std::string(data_.begin() + pos_, data_.begin() + pos_ + length));
                pos_ += length;
                break;
 
            case 0x44: // confirmation
                confirm_.set_iei(iei);
                confirm_.set_length(length);
                confirm_.set_client_id(read_uint32());
                confirm_.set_imei(read_imei());
                confirm_.set_auto_ref_id(read_uint32());
                confirm_.set_status(read_int16());
 
            default: // skip this IE
                pos_ += length;
                break;
        }
 
        if (pos_ < pre_header_.overall_length() + PRE_HEADER_SIZE)
            ie_handler(error, bytes_transferred);
    }
 
    char read_byte() { return data_.at(pos_++) & 0xff; }
 
    unsigned read_uint16()
    {
        unsigned u = (data_.at(pos_++) & 0xff) << BITS_PER_BYTE;
        u |= data_.at(pos_++) & 0xff;
        return u;
    }
 
    int read_int16()
    {
        int i = (data_.at(pos_++) & 0xff) << BITS_PER_BYTE;
        i |= data_.at(pos_++) & 0xff;
 
        // sign extend
        int sign_bit_mask = 0x8000;
        if (i & sign_bit_mask)
            i |= (-1 - 0xFFFF); // extend bits to fill int
 
        return i;
    }
 
    unsigned read_uint32()
    {
        unsigned u = 0;
        for (int i = 0; i < 4; ++i) u |= (data_.at(pos_++) & 0xff) << ((3 - i) * BITS_PER_BYTE);
        return u;
    }
 
    std::string read_imei()
    {
        const int imei_size = 15;
        std::string imei = std::string(data_.begin() + pos_, data_.begin() + pos_ + imei_size);
        pos_ += imei_size;
        return imei;
    }
 
  private:
    goby::acomms::iridium::protobuf::DirectIPMOPreHeader pre_header_;
    goby::acomms::iridium::protobuf::DirectIPMOHeader header_;
    goby::acomms::iridium::protobuf::DirectIPMOPayload body_;
    goby::acomms::iridium::protobuf::DirectIPMTConfirmation confirm_;
 
    boost::asio::ip::tcp::socket& socket_;
 
    std::vector<char>::size_type pos_;
    std::vector<char> data_;
};
 
class SBDMOMessageReader : public SBDMessageReader
{
  public:
    SBDMOMessageReader(boost::asio::ip::tcp::socket& socket) : SBDMessageReader(socket) {}
 
    bool data_ready() const
    {
        return pre_header().IsInitialized() && header().IsInitialized() && body().IsInitialized();
    }
};
 
class SBDMTConfirmationMessageReader : public SBDMessageReader
{
  public:
    SBDMTConfirmationMessageReader(boost::asio::ip::tcp::socket& socket) : SBDMessageReader(socket)
    {
    }
 
    bool data_ready() const { return pre_header().IsInitialized() && confirm().IsInitialized(); }
};
 
class SBDConnection : public boost::enable_shared_from_this<SBDConnection>
{
  public:
    static std::shared_ptr<SBDConnection> create(
        const boost::asio::ip::tcp::socket::executor_type& executor)
    {
        return std::shared_ptr<SBDConnection>(new SBDConnection(executor));
    }
 
    boost::asio::ip::tcp::socket& socket() { return socket_; }
 
    void start()
    {
        remote_endpoint_str_ = boost::lexical_cast<std::string>(socket_.remote_endpoint());
 
        connect_time_ = time::SystemClock::now().time_since_epoch() / std::chrono::seconds(1);
        boost::asio::async_read(socket_, boost::asio::buffer(message_.data()),
                                boost::asio::transfer_at_least(SBDMessageReader::PRE_HEADER_SIZE),
                                boost::bind(&SBDMessageReader::pre_header_handler, &message_,
                                            boost::placeholders::_1, boost::placeholders::_2));
    }
 
    ~SBDConnection() {}
 
    double connect_time() const { return connect_time_; }
 
    const SBDMOMessageReader& message() const { return message_; }
    const std::string& remote_endpoint_str() { return remote_endpoint_str_; }
 
  private:
    SBDConnection(
        const boost::asio::ip::tcp::socket::executor_type& executor)
        : socket_(executor), connect_time_(-1), message_(socket_), remote_endpoint_str_("Unknown")
    {
    }
 
    boost::asio::ip::tcp::socket socket_;
    double connect_time_;
    SBDMOMessageReader message_;
    std::string remote_endpoint_str_;
};
 
class SBDServer
{
  public:
    SBDServer(boost::asio::io_context& io_context, int port, bool ipv6)
        : acceptor_(io_context,
                    boost::asio::ip::tcp::endpoint(
                        ipv6 ? boost::asio::ip::tcp::v6() : boost::asio::ip::tcp::v4(), port))
    {
        start_accept();
    }
 
    std::set<std::shared_ptr<SBDConnection>>& connections() { return connections_; }
 
  private:
    void start_accept()
    {
        std::shared_ptr<SBDConnection> new_connection =
            SBDConnection::create(acceptor_.get_executor());
        connections_.insert(new_connection);
 
        acceptor_.async_accept(new_connection->socket(),
                               boost::bind(&SBDServer::handle_accept, this, new_connection,
                                           boost::asio::placeholders::error));
    }
 
    void handle_accept(std::shared_ptr<SBDConnection> new_connection,
                       const boost::system::error_code& error)
    {
        if (!error)
        {
            using namespace goby::util::logger;
            using goby::glog;
 
            glog.is(DEBUG1) && glog << "Received SBD connection from: "
                                    << new_connection->socket().remote_endpoint() << std::endl;
 
            new_connection->start();
        }
 
        start_accept();
    }
 
    std::set<std::shared_ptr<SBDConnection>> connections_;
    boost::asio::ip::tcp::acceptor acceptor_;
};
 
} // namespace directip
} // namespace acomms
} // namespace goby
 
#endif