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

OpenTTD Source 14.1

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 {
20 private:
21 ClientNetworkStunSocketHandler *stun_handler;
22 std::string token;
23 uint8_t family;
24
25 public:
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
89 std::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>(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
118 ClientNetworkStunSocketHandler::~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 }
TCPConnecter::connection_string
std::string connection_string
Current address we are connecting to (before resolving).
Definition: tcp.h:99
TCPConnecter
"Helper" class for creating TCP connections in a non-blocking manner
Definition: tcp.h:70
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
network_stun.h
NetworkTCPSocketHandler::sock
SOCKET sock
The socket currently connected to.
Definition: tcp.h:38
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
NetworkStunConnectionString
const char * NetworkStunConnectionString()
Get the connection string for the STUN server from the environment variable OTTD_STUN_CS,...
Definition: config.cpp:45
SPS_ALL_SENT
@ SPS_ALL_SENT
All packets in the queue are sent.
Definition: tcp.h:27
Debug
#define Debug(category, level, format_string,...)
Ouptut a line of debugging information.
Definition: debug.h:37
NetworkAddress::GetSockAddress
static NetworkAddress GetSockAddress(SOCKET sock)
Get the local address of a socket as NetworkAddress.
Definition: address.cpp:419
ClientNetworkStunSocketHandler::local_addr
NetworkAddress local_addr
Local addresses of the socket.
Definition: network_stun.h:24
NetworkStunConnecter::OnFailure
void OnFailure() override
Callback for when the connection attempt failed.
Definition: network_stun.cpp:39
network_coordinator.h
ClientNetworkStunSocketHandler::family
uint8_t family
Family of this STUN handler.
Definition: network_stun.h:19
ClientNetworkStunSocketHandler::connecter
std::shared_ptr< TCPConnecter > connecter
Connecter instance.
Definition: network_stun.h:23
NetworkTCPSocketHandler::CloseConnection
virtual NetworkRecvStatus CloseConnection(bool error=true)
This will put this socket handler in a close state.
Definition: tcp.cpp:51
ClientNetworkStunSocketHandler::token
std::string token
Token of this STUN handler.
Definition: network_stun.h:18
ClientNetworkStunSocketHandler::CloseConnection
NetworkRecvStatus CloseConnection(bool error=true) override
This will put this socket handler in a close state.
Definition: network_stun.cpp:105
NetworkTCPSocketHandler::SendPackets
SendPacketsState SendPackets(bool closing_down=false)
Sends all the buffered packets out for this client.
Definition: tcp.cpp:86
NetworkAddress
Wrapper for (un)resolved network addresses; there's no reason to transform a numeric IP to a string a...
Definition: address.h:28
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
NetworkTCPSocketHandler::CanSendReceive
bool CanSendReceive()
Check whether this socket can send or receive something.
Definition: tcp.cpp:200
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
NetworkRecvStatus
NetworkRecvStatus
Status of a network client; reasons why a client has quit.
Definition: core.h:22
_network_coordinator_client
ClientNetworkCoordinatorSocketHandler _network_coordinator_client
The connection to the Game Coordinator.
Definition: network_coordinator.cpp:30
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
network.h
NETWORK_RECV_STATUS_OKAY
@ NETWORK_RECV_STATUS_OKAY
Everything is okay.
Definition: core.h:23
ClientNetworkStunSocketHandler::sent_result
bool sent_result
Did we sent the result of the STUN connection?
Definition: network_stun.h:20
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 byte NETWORK_COORDINATOR_VERSION
What version of game-coordinator-protocol do we use?
Definition: config.h:50
ClientNetworkStunSocketHandler
Class for handling the client side of the STUN connection.
Definition: network_stun.h:16
NetworkStunConnecter
Connect to the STUN server.
Definition: network_stun.cpp:19
PACKET_STUN_SERCLI_STUN
@ PACKET_STUN_SERCLI_STUN
Send a STUN request to the STUN server.
Definition: tcp_stun.h:21