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/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD 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 General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file network_udp.cpp This file handles the UDP related communication.
*
* This is the GameServer <-> GameClient
* communication before the game is being joined.
*/
#include "../stdafx.h"
#include "../date_func.h"
#include "../map_func.h"
#include "../debug.h"
#include "core/game_info.h"
#include "network_gamelist.h"
#include "network_internal.h"
#include "network_udp.h"
#include "network.h"
#include "../core/endian_func.hpp"
#include "../company_base.h"
#include "../rev.h"
#include "../newgrf_text.h"
#include "../strings_func.h"
#include "table/strings.h"
#include "core/udp.h"
#include "../safeguards.h"
static bool _network_udp_server; ///< Is the UDP server started?
static uint16 _network_udp_broadcast; ///< Timeout for the UDP broadcasts.
/** Some information about a socket, which exists before the actual socket has been created to provide locking and the likes. */
struct UDPSocket {
const std::string name; ///< The name of the socket.
NetworkUDPSocketHandler *socket; ///< The actual socket, which may be nullptr when not initialized yet.
UDPSocket(const std::string &name) : name(name), socket(nullptr) {}
void CloseSocket()
{
this->socket->CloseSocket();
delete this->socket;
this->socket = nullptr;
}
void ReceivePackets()
{
this->socket->ReceivePackets();
}
};
static UDPSocket _udp_client("Client"); ///< udp client socket
static UDPSocket _udp_server("Server"); ///< udp server socket
///*** Communication with clients (we are server) ***/
/** Helper class for handling all server side communication. */
class ServerNetworkUDPSocketHandler : public NetworkUDPSocketHandler {
protected:
void Receive_CLIENT_FIND_SERVER(Packet *p, NetworkAddress *client_addr) override;
public:
/**
* Create the socket.
* @param addresses The addresses to bind on.
*/
ServerNetworkUDPSocketHandler(NetworkAddressList *addresses) : NetworkUDPSocketHandler(addresses) {}
virtual ~ServerNetworkUDPSocketHandler() {}
};
void ServerNetworkUDPSocketHandler::Receive_CLIENT_FIND_SERVER(Packet *p, NetworkAddress *client_addr)
{
Packet packet(PACKET_UDP_SERVER_RESPONSE);
this->SendPacket(&packet, client_addr);
Debug(net, 7, "Queried from {}", client_addr->GetHostname());
}
///*** Communication with servers (we are client) ***/
/** Helper class for handling all client side communication. */
class ClientNetworkUDPSocketHandler : public NetworkUDPSocketHandler {
protected:
void Receive_SERVER_RESPONSE(Packet *p, NetworkAddress *client_addr) override;
public:
virtual ~ClientNetworkUDPSocketHandler() {}
};
void ClientNetworkUDPSocketHandler::Receive_SERVER_RESPONSE(Packet *p, NetworkAddress *client_addr)
{
Debug(net, 3, "Server response from {}", client_addr->GetAddressAsString());
NetworkAddServer(client_addr->GetAddressAsString(false), false, true);
}
/** Broadcast to all ips */
static void NetworkUDPBroadCast(NetworkUDPSocketHandler *socket)
{
for (NetworkAddress &addr : _broadcast_list) {
Debug(net, 5, "Broadcasting to {}", addr.GetHostname());
Packet p(PACKET_UDP_CLIENT_FIND_SERVER);
socket->SendPacket(&p, &addr, true, true);
}
}
/** Find all servers */
void NetworkUDPSearchGame()
{
/* We are still searching.. */
if (_network_udp_broadcast > 0) return;
Debug(net, 3, "Searching server");
NetworkUDPBroadCast(_udp_client.socket);
_network_udp_broadcast = 300; // Stay searching for 300 ticks
}
/** Initialize the whole UDP bit. */
void NetworkUDPInitialize()
{
/* If not closed, then do it. */
if (_udp_server.socket != nullptr) NetworkUDPClose();
Debug(net, 3, "Initializing UDP listeners");
assert(_udp_client.socket == nullptr && _udp_server.socket == nullptr);
_udp_client.socket = new ClientNetworkUDPSocketHandler();
NetworkAddressList server;
GetBindAddresses(&server, _settings_client.network.server_port);
_udp_server.socket = new ServerNetworkUDPSocketHandler(&server);
_network_udp_server = false;
_network_udp_broadcast = 0;
}
/** Start the listening of the UDP server component. */
void NetworkUDPServerListen()
{
_network_udp_server = _udp_server.socket->Listen();
}
/** Close all UDP related stuff. */
void NetworkUDPClose()
{
_udp_client.CloseSocket();
_udp_server.CloseSocket();
_network_udp_server = false;
_network_udp_broadcast = 0;
Debug(net, 5, "Closed UDP listeners");
}
/** Receive the UDP packets. */
void NetworkBackgroundUDPLoop()
{
if (_network_udp_server) {
_udp_server.ReceivePackets();
} else {
_udp_client.ReceivePackets();
if (_network_udp_broadcast > 0) _network_udp_broadcast--;
}
}
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