OpenTTD Source: src/network/network_stun.cpp Source File

OpenTTD Source 15.0-beta1

network_stun.cpp
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1/*
2 * This file is part of OpenTTD.
3 * 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.
4 * 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.
5 * 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/>.
6 */
7
10#include "../stdafx.h"
11#include "../debug.h"
12#include "network.h"
13#include "network_coordinator.h"
14#include "network_stun.h"
15
16#include "../safeguards.h"
17
19 class NetworkStunConnecter : public TCPConnecter {
20private:
21 ClientNetworkStunSocketHandler *stun_handler;
22 std::string token;
23 uint8_t family;
24
25public:
31 NetworkStunConnecter(ClientNetworkStunSocketHandler *stun_handler, const std::string &connection_string, const std::string &token, uint8_t family) :
32 TCPConnecter(connection_string, NETWORK_STUN_SERVER_PORT, NetworkAddress(), family),
33 stun_handler(stun_handler),
34 token(token),
35 family(family)
36 {
37 }
38
39 void OnFailure() override
40 {
41 Debug(net, 9, "Stun::OnFailure(): family={}", this->family);
42
43 this->stun_handler->connecter = nullptr;
44
45 /* Connection to STUN server failed. For example, the client doesn't
46 * support IPv6, which means it will fail that attempt. */
47
48 _network_coordinator_client.StunResult(this->token, this->family, false);
49 }
50
51 void OnConnect(SOCKET s) override
52 {
53 Debug(net, 9, "Stun::OnConnect(): family={}", this->family);
54
55 this->stun_handler->connecter = nullptr;
56
57 assert(this->stun_handler->sock == INVALID_SOCKET);
58 this->stun_handler->sock = s;
59
60 /* Store the local address; later connects will reuse it again.
61 * This is what makes STUN work for most NATs. */
62 this->stun_handler->local_addr = NetworkAddress::GetSockAddress(s);
63
64 /* We leave the connection open till the real connection is setup later. */
65 }
66};
67
73 void ClientNetworkStunSocketHandler::Connect(const std::string &token, uint8_t family)
74{
75 this->token = token;
76 this->family = family;
77
78 Debug(net, 9, "Stun::Connect(): family={}", this->family);
79
80 this->connecter = TCPConnecter::Create<NetworkStunConnecter>(this, NetworkStunConnectionString(), token, family);
81}
82
89std::unique_ptr<ClientNetworkStunSocketHandler> ClientNetworkStunSocketHandler::Stun(const std::string &token, uint8_t family)
90{
91 auto stun_handler = std::make_unique<ClientNetworkStunSocketHandler>();
92
93 stun_handler->Connect(token, family);
94
95 auto p = std::make_unique<Packet>(stun_handler.get(), PACKET_STUN_SERCLI_STUN);
96 p->Send_uint8(NETWORK_COORDINATOR_VERSION);
97 p->Send_string(token);
98 p->Send_uint8(family);
99
100 stun_handler->SendPacket(std::move(p));
101
102 return stun_handler;
103}
104
105 NetworkRecvStatus ClientNetworkStunSocketHandler::CloseConnection(bool error)
106{
107 NetworkStunSocketHandler::CloseConnection(error);
108
109 /* Also make sure any pending connecter is killed ASAP. */
110 if (this->connecter != nullptr) {
111 this->connecter->Kill();
112 this->connecter = nullptr;
113 }
114
115 return NETWORK_RECV_STATUS_OKAY;
116}
117
118ClientNetworkStunSocketHandler::~ClientNetworkStunSocketHandler()
119{
120 if (this->connecter != nullptr) {
121 this->connecter->Kill();
122 this->connecter = nullptr;
123 }
124}
125
130 void ClientNetworkStunSocketHandler::SendReceive()
131{
132 if (this->sock == INVALID_SOCKET) return;
133
134 /* We never attempt to receive anything on a STUN socket. After
135 * connecting a STUN connection, the local address will be reused to
136 * to establish the connection with the real server. If we would be to
137 * read this socket, some OSes get confused and deliver us packets meant
138 * for the real connection. It appears most OSes play best when we simply
139 * never attempt to read it to start with (and the packets will remain
140 * available on the other socket).
141 * Protocol-wise, the STUN server will never send any packet back anyway. */
142
143 this->CanSendReceive();
144 if (this->SendPackets() == SPS_ALL_SENT && !this->sent_result) {
145 /* We delay giving the GC the result this long, as to make sure we
146 * have sent the STUN packet first. This means the GC is more likely
147 * to have the result ready by the time our StunResult() packet
148 * arrives. */
149 this->sent_result = true;
150 _network_coordinator_client.StunResult(this->token, this->family, true);
151 }
152}
ClientNetworkCoordinatorSocketHandler::StunResult
void StunResult(const std::string &token, uint8_t family, bool result)
Callback from the STUN connecter to inform the Game Coordinator about the result of the STUN.
Definition network_coordinator.cpp:607
ClientNetworkStunSocketHandler
Class for handling the client side of the STUN connection.
Definition network_stun.h:16
ClientNetworkStunSocketHandler::Connect
void Connect(const std::string &token, uint8_t family)
Connect to the STUN server over either IPv4 or IPv6.
Definition network_stun.cpp:73
ClientNetworkStunSocketHandler::token
std::string token
Token of this STUN handler.
Definition network_stun.h:18
ClientNetworkStunSocketHandler::SendReceive
void SendReceive()
Check whether we received/can send some data from/to the STUN server and when that's the case handle ...
Definition network_stun.cpp:130
ClientNetworkStunSocketHandler::family
uint8_t family
Family of this STUN handler.
Definition network_stun.h:19
ClientNetworkStunSocketHandler::Stun
static std::unique_ptr< ClientNetworkStunSocketHandler > Stun(const std::string &token, uint8_t family)
Send a STUN packet to the STUN server.
Definition network_stun.cpp:89
ClientNetworkStunSocketHandler::connecter
std::shared_ptr< TCPConnecter > connecter
Connecter instance.
Definition network_stun.h:23
ClientNetworkStunSocketHandler::local_addr
NetworkAddress local_addr
Local addresses of the socket.
Definition network_stun.h:24
ClientNetworkStunSocketHandler::CloseConnection
NetworkRecvStatus CloseConnection(bool error=true) override
This will put this socket handler in a close state.
Definition network_stun.cpp:105
ClientNetworkStunSocketHandler::sent_result
bool sent_result
Did we sent the result of the STUN connection?
Definition network_stun.h:20
NetworkAddress
Wrapper for (un)resolved network addresses; there's no reason to transform a numeric IP to a string a...
Definition address.h:28
NetworkAddress::GetSockAddress
static NetworkAddress GetSockAddress(SOCKET sock)
Get the local address of a socket as NetworkAddress.
Definition address.cpp:419
NetworkStunConnecter
Connect to the STUN server.
Definition network_stun.cpp:19
NetworkStunConnecter::OnConnect
void OnConnect(SOCKET s) override
Callback when the connection succeeded.
Definition network_stun.cpp:51
NetworkStunConnecter::NetworkStunConnecter
NetworkStunConnecter(ClientNetworkStunSocketHandler *stun_handler, const std::string &connection_string, const std::string &token, uint8_t family)
Initiate the connecting.
Definition network_stun.cpp:31
NetworkStunConnecter::OnFailure
void OnFailure() override
Callback for when the connection attempt failed.
Definition network_stun.cpp:39
NetworkTCPSocketHandler::CloseConnection
virtual NetworkRecvStatus CloseConnection(bool error=true)
This will put this socket handler in a close state.
Definition tcp.cpp:51
NetworkTCPSocketHandler::sock
SOCKET sock
The socket currently connected to.
Definition tcp.h:38
NetworkTCPSocketHandler::SendPackets
SendPacketsState SendPackets(bool closing_down=false)
Sends all the buffered packets out for this client.
Definition tcp.cpp:86
NetworkTCPSocketHandler::CanSendReceive
bool CanSendReceive()
Check whether this socket can send or receive something.
Definition tcp.cpp:204
TCPConnecter
"Helper" class for creating TCP connections in a non-blocking manner
Definition tcp.h:70
TCPConnecter::connection_string
std::string connection_string
Current address we are connecting to (before resolving).
Definition tcp.h:99
NetworkStunConnectionString
const char * NetworkStunConnectionString()
Get the connection string for the STUN server from the environment variable OTTD_STUN_CS,...
Definition config.cpp:45
NETWORK_STUN_SERVER_PORT
static const uint16_t NETWORK_STUN_SERVER_PORT
The default port of the STUN server (TCP)
Definition config.h:22
NETWORK_COORDINATOR_VERSION
static const uint8_t NETWORK_COORDINATOR_VERSION
What version of game-coordinator-protocol do we use?
Definition config.h:50
NetworkRecvStatus
NetworkRecvStatus
Status of a network client; reasons why a client has quit.
Definition core.h:23
NETWORK_RECV_STATUS_OKAY
@ NETWORK_RECV_STATUS_OKAY
Everything is okay.
Definition core.h:24
Debug
#define Debug(category, level, format_string,...)
Ouptut a line of debugging information.
Definition debug.h:37
network.h
Basic functions/variables used all over the place.
_network_coordinator_client
ClientNetworkCoordinatorSocketHandler _network_coordinator_client
The connection to the Game Coordinator.
Definition network_coordinator.cpp:30
network_coordinator.h
Part of the network protocol handling Game Coordinator requests.
network_stun.h
Part of the network protocol handling STUN requests.
SPS_ALL_SENT
@ SPS_ALL_SENT
All packets in the queue are sent.
Definition tcp.h:27
PACKET_STUN_SERCLI_STUN
@ PACKET_STUN_SERCLI_STUN
Send a STUN request to the STUN server.
Definition tcp_stun.h:21