NotifierInstance.cpp

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/*
    Copyright (C) 2014-2016 Leosac

    This file is part of Leosac.

    Leosac is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Leosac is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

#include "NotifierInstance.hpp"
#include "core/auth/Auth.hpp"
#include "core/credentials/RFIDCard.hpp"
#include "tools/Colorize.hpp"
#include "tools/log.hpp"
#include <zmqpp/message.hpp>

using namespace Leosac;
using namespace Leosac::Module;
using namespace Leosac::Module::TCPNotifier;

NotifierInstance::NotifierInstance(zmqpp::context &ctx, zmqpp::reactor &reactor,
                                   std::vector<std::string> auth_sources,
                                   std::vector<std::string> connect_to,
                                   std::vector<std::string> bind_to,
                                   ProtocolHandlerUPtr protocol_handler)
    : bus_sub_(ctx, zmqpp::socket_type::sub)
    , tcp_(ctx, zmqpp::socket_type::stream)
    , protocol_(std::move(protocol_handler))
{
    ASSERT_LOG(connect_to.empty() || bind_to.empty(),
               "Cannot bind and connect at the same time.");
    ASSERT_LOG(!connect_to.empty() || !bind_to.empty(), "Cannot do nothing");
    ASSERT_LOG(protocol_, "No protocol handler");

    act_as_server_ = !bind_to.empty();

    bus_sub_.connect("inproc://zmq-bus-pub");
    for (const auto &src : auth_sources)
    {
        bus_sub_.subscribe("S_" + src);
    }
    reactor.add(bus_sub_, std::bind(&NotifierInstance::handle_msg_bus, this));

    configure_tcp_socket(act_as_server_ ? bind_to : connect_to);
    reactor.add(tcp_, std::bind(&NotifierInstance::handle_tcp_msg, this));
}

void NotifierInstance::handle_credential(Leosac::Cred::RFIDCard &card)
{
    for (const auto &target : targets_)
    {
        // Skip disconnected client.
        if (!target.status_)
            continue;
        zmqpp::message msg;

        msg << target.zmq_identity_;
        try
        {
            auto data = protocol_->build_cred_msg(card);
            msg.add_raw(&data[0], data.size());
        }
        catch (const ProtocolException &e)
        {
            WARN("TCPNotifier: Protocol error: " << e.what());
            continue;
        }
        auto ret = tcp_.send(msg, true);
        if (ret == false) // would block. woops
        {
            ERROR("Sending to client would block.");
        }
    }
}

void NotifierInstance::handle_one(zmqpp::message &msg)
{
    std::string routing_id;
    std::string data;

    assert(msg.parts() == 2);
    msg >> routing_id >> data;

    if (data.size() == 0)
    {
        auto target = find_target(routing_id);
        if (act_as_server_)
        {
            // As a server we drop disconnected peer, or create a TargetInfo
            // for newly connected peer.
            if (!target)
            {
                TargetInfo ti;
                ti.status_       = true;
                ti.zmq_identity_ = routing_id;

                targets_.push_back(std::move(ti));
                INFO("TCP-Notifier: New client connected.");
            }
            else
            {
                targets_.erase(std::remove_if(targets_.begin(), targets_.end(),
                                              [&](const TargetInfo &info) {
                                                  return info.zmq_identity_ ==
                                                         routing_id;
                                              }),
                               targets_.end());
                INFO("TCP-Notifier: Client disconnected.");
            }
            return;
        }
        ASSERT_LOG(target, "Why did we lose a target?");

        if (target->status_)
            INFO("Lost connection with client.");
        else
            INFO("Successfully connected to client.");

        target->status_ = !target->status_;
    }
}

void NotifierInstance::handle_tcp_msg()
{
    zmqpp::message msg;

    while (tcp_.receive(msg, true))
    {
        handle_one(msg);
    }
}

NotifierInstance::TargetInfo *
NotifierInstance::find_target(const std::string &routing_id)
{
    auto itr = std::find_if(targets_.begin(), targets_.end(),
                            [&](const TargetInfo &target) {
                                return target.zmq_identity_ == routing_id;
                            });
    if (itr != targets_.end())
        return &(*itr);
    return nullptr;
}

void NotifierInstance::handle_msg_bus()
{
    zmqpp::message msg;
    std::string src;
    Leosac::Auth::SourceType type;
    std::string card;
    int bits;

    bus_sub_.receive(msg);
    if (msg.parts() < 4)
    {
        WARN("Unexpected message content.");
        return;
    }
    msg >> src >> type >> card >> bits;
    if (type != Leosac::Auth::SourceType::SIMPLE_WIEGAND)
    {
        INFO("TCP-Notifier cannot handle this type of credential yet.");
        return;
    }
    auto wiegand_card = std::make_shared<Cred::RFIDCard>();
    wiegand_card->card_id(card);
    wiegand_card->nb_bits(bits);

    handle_credential(*wiegand_card);
}

void NotifierInstance::configure_tcp_socket(
    const std::vector<std::string> &endpoints)
{
    tcp_.set(zmqpp::socket_option::backlog, 5);
    if (act_as_server_)
    {
        for (auto &endpoint : endpoints)
        {
            INFO("TCP-Notifier binding to: tcp://" << endpoint);
            tcp_.bind("tcp://" + endpoint);
        }
    }
    else
    {
        for (auto &endpoint : endpoints)
        {
            TargetInfo target;
            target.url_    = "tcp://" + endpoint;
            target.status_ = false;
            tcp_.connect(target.url_);
            INFO("TCP-Notifier remote target: " << Colorize::green(target.url_));
            tcp_.get(zmqpp::socket_option::identity, target.zmq_identity_);
            targets_.push_back(std::move(target));
        }
    }
}