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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 tcp.h Basic functions to receive and send TCP packets.
*/
#ifndef NETWORK_CORE_TCP_H
#define NETWORK_CORE_TCP_H
#include "address.h"
#include "packet.h"
#include <atomic>
#include <chrono>
#include <map>
#include <thread>
/** The states of sending the packets. */
enum SendPacketsState {
SPS_CLOSED, ///< The connection got closed.
SPS_NONE_SENT, ///< The buffer is still full, so no (parts of) packets could be sent.
SPS_PARTLY_SENT, ///< The packets are partly sent; there are more packets to be sent in the queue.
SPS_ALL_SENT, ///< All packets in the queue are sent.
};
/** Base socket handler for all TCP sockets */
class NetworkTCPSocketHandler : public NetworkSocketHandler {
private:
Packet *packet_queue; ///< Packets that are awaiting delivery
Packet *packet_recv; ///< Partially received packet
void EmptyPacketQueue();
public:
SOCKET sock; ///< The socket currently connected to
bool writable; ///< Can we write to this socket?
/**
* Whether this socket is currently bound to a socket.
* @return true when the socket is bound, false otherwise
*/
bool IsConnected() const { return this->sock != INVALID_SOCKET; }
virtual NetworkRecvStatus CloseConnection(bool error = true);
void CloseSocket();
virtual void SendPacket(Packet *packet);
SendPacketsState SendPackets(bool closing_down = false);
virtual Packet *ReceivePacket();
bool CanSendReceive();
/**
* Whether there is something pending in the send queue.
* @return true when something is pending in the send queue.
*/
bool HasSendQueue() { return this->packet_queue != nullptr; }
NetworkTCPSocketHandler(SOCKET s = INVALID_SOCKET);
~NetworkTCPSocketHandler();
};
/**
* "Helper" class for creating TCP connections in a non-blocking manner
*/
class TCPConnecter {
private:
/**
* The current status of the connecter.
*
* We track the status like this to ensure everything is executed from the
* game-thread, and not at another random time where we might not have the
* lock on the game-state.
*/
enum class Status {
INIT, ///< TCPConnecter is created but resolving hasn't started.
RESOLVING, ///< The hostname is being resolved (threaded).
FAILURE, ///< Resolving failed.
CONNECTING, ///< We are currently connecting.
CONNECTED, ///< The connection is established.
};
std::thread resolve_thread; ///< Thread used during resolving.
std::atomic<Status> status = Status::INIT; ///< The current status of the connecter.
std::atomic<bool> killed = false; ///< Whether this connecter is marked as killed.
addrinfo *ai = nullptr; ///< getaddrinfo() allocated linked-list of resolved addresses.
std::vector<addrinfo *> addresses; ///< Addresses we can connect to.
std::map<SOCKET, NetworkAddress> sock_to_address; ///< Mapping of a socket to the real address it is connecting to. USed for DEBUG statements.
size_t current_address = 0; ///< Current index in addresses we are trying.
std::vector<SOCKET> sockets; ///< Pending connect() attempts.
std::chrono::steady_clock::time_point last_attempt; ///< Time we last tried to connect.
std::string connection_string; ///< Current address we are connecting to (before resolving).
NetworkAddress bind_address; ///< Address we're binding to, if any.
void Resolve();
void OnResolved(addrinfo *ai);
bool TryNextAddress();
void Connect(addrinfo *address);
virtual bool CheckActivity();
/* We do not want any other derived classes from this class being able to
* access these private members, but it is okay for TCPServerConnecter. */
friend class TCPServerConnecter;
static void ResolveThunk(TCPConnecter *connecter);
public:
TCPConnecter() {};
TCPConnecter(const std::string &connection_string, uint16 default_port, NetworkAddress bind_address = {});
virtual ~TCPConnecter();
/**
* Callback when the connection succeeded.
* @param s the socket that we opened
*/
virtual void OnConnect(SOCKET s) {}
/**
* Callback for when the connection attempt failed.
*/
virtual void OnFailure() {}
void Kill();
static void CheckCallbacks();
static void KillAll();
};
class TCPServerConnecter : public TCPConnecter {
private:
SOCKET socket = INVALID_SOCKET; ///< The socket when a connection is established.
bool CheckActivity() override;
public:
ServerAddress server_address; ///< Address we are connecting to.
TCPServerConnecter(const std::string &connection_string, uint16 default_port);
void SetConnected(SOCKET sock);
void SetFailure();
};
#endif /* NETWORK_CORE_TCP_H */
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