summaryrefslogtreecommitdiff
path: root/src/network/network_coordinator.cpp
blob: c3fa2b5ce5ce654a6480c7ae75bea0b906835270 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
/*
 * 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_coordinator.cpp Game Coordinator sending/receiving part of the network protocol. */

#include "../stdafx.h"
#include "../debug.h"
#include "../error.h"
#include "../rev.h"
#include "../settings_type.h"
#include "../strings_func.h"
#include "../window_func.h"
#include "../window_type.h"
#include "network.h"
#include "network_coordinator.h"
#include "network_gamelist.h"
#include "network_gui.h"
#include "network_internal.h"
#include "network_server.h"
#include "network_stun.h"
#include "table/strings.h"

#include "../safeguards.h"

static const auto NETWORK_COORDINATOR_DELAY_BETWEEN_UPDATES = std::chrono::seconds(30); ///< How many time between updates the server sends to the Game Coordinator.
ClientNetworkCoordinatorSocketHandler _network_coordinator_client; ///< The connection to the Game Coordinator.
ConnectionType _network_server_connection_type = CONNECTION_TYPE_UNKNOWN; ///< What type of connection the Game Coordinator detected we are on.
std::string _network_server_invite_code = ""; ///< Our invite code as indicated by the Game Coordinator.

/** Connect to a game server by IP:port. */
class NetworkDirectConnecter : public TCPConnecter {
private:
	std::string token;     ///< Token of this connection.
	uint8 tracking_number; ///< Tracking number of this connection.

public:
	/**
	 * Try to establish a direct (hostname:port based) connection.
	 * @param hostname The hostname of the server.
	 * @param port The port of the server.
	 * @param token The token as given by the Game Coordinator to track this connection attempt.
	 * @param tracking_number The tracking number as given by the Game Coordinator to track this connection attempt.
	 */
	NetworkDirectConnecter(const std::string &hostname, uint16 port, const std::string &token, uint8 tracking_number) : TCPConnecter(hostname, port), token(token), tracking_number(tracking_number) {}

	void OnFailure() override
	{
		_network_coordinator_client.ConnectFailure(this->token, this->tracking_number);
	}

	void OnConnect(SOCKET s) override
	{
		NetworkAddress address = NetworkAddress::GetPeerAddress(s);
		_network_coordinator_client.ConnectSuccess(this->token, s, address);
	}
};

/** Connecter used after STUN exchange to connect from both sides to each other. */
class NetworkReuseStunConnecter : public TCPConnecter {
private:
	std::string token;     ///< Token of this connection.
	uint8 tracking_number; ///< Tracking number of this connection.
	uint8 family;          ///< Family of this connection.

public:
	/**
	 * Try to establish a STUN-based connection.
	 * @param hostname The hostname of the peer.
	 * @param port The port of the peer.
	 * @param bind_address The local bind address used for this connection.
	 * @param token The connection token.
	 * @param tracking_number The tracking number of the connection.
	 * @param family The family this connection is using.
	 */
	NetworkReuseStunConnecter(const std::string &hostname, uint16 port, const NetworkAddress &bind_address, std::string token, uint8 tracking_number, uint8 family) :
		TCPConnecter(hostname, port, bind_address),
		token(token),
		tracking_number(tracking_number),
		family(family)
	{
	}

	void OnFailure() override
	{
		/* Close the STUN connection too, as it is no longer of use. */
		_network_coordinator_client.CloseStunHandler(this->token, this->family);

		_network_coordinator_client.ConnectFailure(this->token, this->tracking_number);
	}

	void OnConnect(SOCKET s) override
	{
		NetworkAddress address = NetworkAddress::GetPeerAddress(s);
		_network_coordinator_client.ConnectSuccess(this->token, s, address);
	}
};

/** Connect to the Game Coordinator server. */
class NetworkCoordinatorConnecter : TCPConnecter {
public:
	/**
	 * Initiate the connecting.
	 * @param connection_string The address of the Game Coordinator server.
	 */
	NetworkCoordinatorConnecter(const std::string &connection_string) : TCPConnecter(connection_string, NETWORK_COORDINATOR_SERVER_PORT) {}

	void OnFailure() override
	{
		_network_coordinator_client.connecting = false;
		_network_coordinator_client.CloseConnection(true);
	}

	void OnConnect(SOCKET s) override
	{
		assert(_network_coordinator_client.sock == INVALID_SOCKET);

		_network_coordinator_client.sock = s;
		_network_coordinator_client.last_activity = std::chrono::steady_clock::now();
		_network_coordinator_client.connecting = false;
	}
};

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_ERROR(Packet *p)
{
	NetworkCoordinatorErrorType error = (NetworkCoordinatorErrorType)p->Recv_uint8();
	std::string detail = p->Recv_string(NETWORK_ERROR_DETAIL_LENGTH);

	switch (error) {
		case NETWORK_COORDINATOR_ERROR_UNKNOWN:
			this->CloseConnection();
			return false;

		case NETWORK_COORDINATOR_ERROR_REGISTRATION_FAILED:
			ShowErrorMessage(STR_NETWORK_ERROR_COORDINATOR_REGISTRATION_FAILED, INVALID_STRING_ID, WL_ERROR);

			/* To prevent that we constantly try to reconnect, switch to local game. */
			_settings_client.network.server_game_type = SERVER_GAME_TYPE_LOCAL;

			this->CloseConnection();
			return false;

		case NETWORK_COORDINATOR_ERROR_INVALID_INVITE_CODE: {
			auto connecter_pre_it = this->connecter_pre.find(detail);
			if (connecter_pre_it != this->connecter_pre.end()) {
				connecter_pre_it->second->SetFailure();
				this->connecter_pre.erase(connecter_pre_it);
			}

			/* Mark the server as offline. */
			NetworkGameList *item = NetworkGameListAddItem(detail);
			item->status = NGLS_OFFLINE;

			UpdateNetworkGameWindow();
			return true;
		}

		case NETWORK_COORDINATOR_ERROR_REUSE_OF_INVITE_CODE:
			ShowErrorMessage(STR_NETWORK_ERROR_COORDINATOR_REUSE_OF_INVITE_CODE, INVALID_STRING_ID, WL_ERROR);

			/* To prevent that we constantly battle for the same invite-code, switch to local game. */
			_settings_client.network.server_game_type = SERVER_GAME_TYPE_LOCAL;

			this->CloseConnection();
			return false;

		default:
			Debug(net, 0, "Invalid error type {} received from Game Coordinator", error);
			this->CloseConnection();
			return false;
	}
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_REGISTER_ACK(Packet *p)
{
	/* Schedule sending an update. */
	this->next_update = std::chrono::steady_clock::now();

	_settings_client.network.server_invite_code = p->Recv_string(NETWORK_INVITE_CODE_LENGTH);
	_settings_client.network.server_invite_code_secret = p->Recv_string(NETWORK_INVITE_CODE_SECRET_LENGTH);
	_network_server_connection_type = (ConnectionType)p->Recv_uint8();

	if (_network_server_connection_type == CONNECTION_TYPE_ISOLATED) {
		ShowErrorMessage(STR_NETWORK_ERROR_COORDINATOR_ISOLATED, STR_NETWORK_ERROR_COORDINATOR_ISOLATED_DETAIL, WL_ERROR);
	}

	/* Users can change the invite code in the settings, but this has no effect
	 * on the invite code as assigned by the server. So
	 * _network_server_invite_code contains the current invite code,
	 * and _settings_client.network.server_invite_code contains the one we will
	 * attempt to re-use when registering again. */
	_network_server_invite_code = _settings_client.network.server_invite_code;

	SetWindowDirty(WC_CLIENT_LIST, 0);

	if (_network_dedicated) {
		std::string connection_type;
		switch (_network_server_connection_type) {
			case CONNECTION_TYPE_ISOLATED: connection_type = "Remote players can't connect"; break;
			case CONNECTION_TYPE_DIRECT:   connection_type = "Public"; break;
			case CONNECTION_TYPE_STUN:     connection_type = "Behind NAT"; break;
			case CONNECTION_TYPE_TURN:     connection_type = "Via relay"; break;

			case CONNECTION_TYPE_UNKNOWN: // Never returned from Game Coordinator.
			default: connection_type = "Unknown"; break; // Should never happen, but don't fail if it does.
		}

		std::string game_type;
		switch (_settings_client.network.server_game_type) {
			case SERVER_GAME_TYPE_INVITE_ONLY: game_type = "Invite only"; break;
			case SERVER_GAME_TYPE_PUBLIC: game_type = "Public"; break;

			case SERVER_GAME_TYPE_LOCAL: // Impossible to register local servers.
			default: game_type = "Unknown"; break; // Should never happen, but don't fail if it does.
		}

		Debug(net, 3, "----------------------------------------");
		Debug(net, 3, "Your server is now registered with the Game Coordinator:");
		Debug(net, 3, "  Game type:       {}", game_type);
		Debug(net, 3, "  Connection type: {}", connection_type);
		Debug(net, 3, "  Invite code:     {}", _network_server_invite_code);
		Debug(net, 3, "----------------------------------------");
	} else {
		Debug(net, 3, "Game Coordinator registered our server with invite code '{}'", _network_server_invite_code);
	}

	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_LISTING(Packet *p)
{
	uint8 servers = p->Recv_uint16();

	/* End of list; we can now remove all expired items from the list. */
	if (servers == 0) {
		NetworkGameListRemoveExpired();
		return true;
	}

	for (; servers > 0; servers--) {
		std::string connection_string = p->Recv_string(NETWORK_HOSTNAME_PORT_LENGTH);

		/* Read the NetworkGameInfo from the packet. */
		NetworkGameInfo ngi = {};
		DeserializeNetworkGameInfo(p, &ngi, &this->newgrf_lookup_table);

		/* Now we know the connection string, we can add it to our list. */
		NetworkGameList *item = NetworkGameListAddItem(connection_string);

		/* Clear any existing GRFConfig chain. */
		ClearGRFConfigList(&item->info.grfconfig);
		/* Copy the new NetworkGameInfo info. */
		item->info = ngi;
		/* Check for compatability with the client. */
		CheckGameCompatibility(item->info);
		/* Mark server as online. */
		item->status = NGLS_ONLINE;
		/* Mark the item as up-to-date. */
		item->version = _network_game_list_version;
	}

	UpdateNetworkGameWindow();
	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_CONNECTING(Packet *p)
{
	std::string token = p->Recv_string(NETWORK_TOKEN_LENGTH);
	std::string invite_code = p->Recv_string(NETWORK_INVITE_CODE_LENGTH);

	/* Find the connecter based on the invite code. */
	auto connecter_pre_it = this->connecter_pre.find(invite_code);
	if (connecter_pre_it == this->connecter_pre.end()) {
		this->CloseConnection();
		return false;
	}

	/* Now store it based on the token. */
	this->connecter[token] = {invite_code, connecter_pre_it->second};
	this->connecter_pre.erase(connecter_pre_it);

	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_CONNECT_FAILED(Packet *p)
{
	std::string token = p->Recv_string(NETWORK_TOKEN_LENGTH);
	this->CloseToken(token);

	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_DIRECT_CONNECT(Packet *p)
{
	std::string token = p->Recv_string(NETWORK_TOKEN_LENGTH);
	uint8 tracking_number = p->Recv_uint8();
	std::string hostname = p->Recv_string(NETWORK_HOSTNAME_LENGTH);
	uint16 port = p->Recv_uint16();

	/* Ensure all other pending connection attempts are killed. */
	if (this->game_connecter != nullptr) {
		this->game_connecter->Kill();
		this->game_connecter = nullptr;
	}

	this->game_connecter = new NetworkDirectConnecter(hostname, port, token, tracking_number);
	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_STUN_REQUEST(Packet *p)
{
	std::string token = p->Recv_string(NETWORK_TOKEN_LENGTH);

	this->stun_handlers[token][AF_INET6] = ClientNetworkStunSocketHandler::Stun(token, AF_INET6);
	this->stun_handlers[token][AF_INET] = ClientNetworkStunSocketHandler::Stun(token, AF_INET);
	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_STUN_CONNECT(Packet *p)
{
	std::string token = p->Recv_string(NETWORK_TOKEN_LENGTH);
	uint8 tracking_number = p->Recv_uint8();
	uint8 family = p->Recv_uint8();
	std::string host = p->Recv_string(NETWORK_HOSTNAME_PORT_LENGTH);
	uint16 port = p->Recv_uint16();

	/* Check if we know this token. */
	auto stun_it = this->stun_handlers.find(token);
	if (stun_it == this->stun_handlers.end()) return true;
	auto family_it = stun_it->second.find(family);
	if (family_it == stun_it->second.end()) return true;

	/* Ensure all other pending connection attempts are killed. */
	if (this->game_connecter != nullptr) {
		this->game_connecter->Kill();
		this->game_connecter = nullptr;
	}

	/* We now mark the connection as closed, but we do not really close the
	 * socket yet. We do this when the NetworkReuseStunConnecter is connected.
	 * This prevents any NAT to already remove the route while we create the
	 * second connection on top of the first. */
	family_it->second->CloseConnection(false);

	/* Connect to our peer from the same local address as we use for the
	 * STUN server. This means that if there is any NAT in the local network,
	 * the public ip:port is still pointing to the local address, and as such
	 * a connection can be established. */
	this->game_connecter = new NetworkReuseStunConnecter(host, port, family_it->second->local_addr, token, tracking_number, family);
	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_NEWGRF_LOOKUP(Packet *p)
{
	this->newgrf_lookup_table_cursor = p->Recv_uint32();

	uint16 newgrfs = p->Recv_uint16();
	for (; newgrfs> 0; newgrfs--) {
		uint32 index = p->Recv_uint32();
		DeserializeGRFIdentifierWithName(p, &this->newgrf_lookup_table[index]);
	}
	return true;
}

bool ClientNetworkCoordinatorSocketHandler::Receive_GC_TURN_CONNECT(Packet *p)
{
	std::string token = p->Recv_string(NETWORK_TOKEN_LENGTH);
	uint8 tracking_number = p->Recv_uint8();
	std::string ticket = p->Recv_string(NETWORK_TOKEN_LENGTH);
	std::string connection_string = p->Recv_string(NETWORK_HOSTNAME_PORT_LENGTH);

	/* Ensure all other pending connection attempts are killed. */
	if (this->game_connecter != nullptr) {
		this->game_connecter->Kill();
		this->game_connecter = nullptr;
	}

	this->turn_handlers[token] = ClientNetworkTurnSocketHandler::Turn(token, tracking_number, ticket, connection_string);

	if (!_network_server) {
		auto connecter_it = this->connecter.find(token);
		if (connecter_it == this->connecter.end()) {
			/* Make sure we are still interested in connecting to this server. */
			this->ConnectFailure(token, 0);
			return true;
		}

		switch (_settings_client.network.use_relay_service) {
			case URS_NEVER:
				this->ConnectFailure(token, 0);
				break;

			case URS_ASK:
				ShowNetworkAskRelay(connecter_it->second.first, connection_string, token);
				break;

			case URS_ALLOW:
				this->StartTurnConnection(token);
				break;
		}
	} else {
		this->StartTurnConnection(token);
	}

	return true;
}

void ClientNetworkCoordinatorSocketHandler::StartTurnConnection(std::string &token)
{
	auto turn_it = this->turn_handlers.find(token);
	if (turn_it == this->turn_handlers.end()) return;

	turn_it->second->Connect();
}

void ClientNetworkCoordinatorSocketHandler::Connect()
{
	/* We are either already connected or are trying to connect. */
	if (this->sock != INVALID_SOCKET || this->connecting) return;

	this->Reopen();

	this->connecting = true;
	this->last_activity = std::chrono::steady_clock::now();

	new NetworkCoordinatorConnecter(NetworkCoordinatorConnectionString());
}

NetworkRecvStatus ClientNetworkCoordinatorSocketHandler::CloseConnection(bool error)
{
	NetworkCoordinatorSocketHandler::CloseConnection(error);

	this->CloseSocket();
	this->connecting = false;

	_network_server_connection_type = CONNECTION_TYPE_UNKNOWN;
	this->next_update = {};

	this->CloseAllConnections();

	SetWindowDirty(WC_CLIENT_LIST, 0);

	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Register our server to receive our invite code.
 */
void ClientNetworkCoordinatorSocketHandler::Register()
{
	_network_server_connection_type = CONNECTION_TYPE_UNKNOWN;
	this->next_update = {};

	SetWindowDirty(WC_CLIENT_LIST, 0);

	this->Connect();

	Packet *p = new Packet(PACKET_COORDINATOR_SERVER_REGISTER);
	p->Send_uint8(NETWORK_COORDINATOR_VERSION);
	p->Send_uint8(_settings_client.network.server_game_type);
	p->Send_uint16(_settings_client.network.server_port);
	if (_settings_client.network.server_invite_code.empty() || _settings_client.network.server_invite_code_secret.empty()) {
		p->Send_string("");
		p->Send_string("");
	} else {
		p->Send_string(_settings_client.network.server_invite_code);
		p->Send_string(_settings_client.network.server_invite_code_secret);
	}

	this->SendPacket(p);
}

/**
 * Send an update of our server status to the Game Coordinator.
 */
void ClientNetworkCoordinatorSocketHandler::SendServerUpdate()
{
	Debug(net, 6, "Sending server update to Game Coordinator");

	Packet *p = new Packet(PACKET_COORDINATOR_SERVER_UPDATE, TCP_MTU);
	p->Send_uint8(NETWORK_COORDINATOR_VERSION);
	SerializeNetworkGameInfo(p, GetCurrentNetworkServerGameInfo(), this->next_update.time_since_epoch() != std::chrono::nanoseconds::zero());

	this->SendPacket(p);

	this->next_update = std::chrono::steady_clock::now() + NETWORK_COORDINATOR_DELAY_BETWEEN_UPDATES;
}

/**
 * Request a listing of all public servers.
 */
void ClientNetworkCoordinatorSocketHandler::GetListing()
{
	this->Connect();

	_network_game_list_version++;

	Packet *p = new Packet(PACKET_COORDINATOR_CLIENT_LISTING);
	p->Send_uint8(NETWORK_COORDINATOR_VERSION);
	p->Send_uint8(NETWORK_GAME_INFO_VERSION);
	p->Send_string(_openttd_revision);
	p->Send_uint32(this->newgrf_lookup_table_cursor);

	this->SendPacket(p);
}

/**
 * Join a server based on an invite code.
 * @param invite_code The invite code of the server to connect to.
 * @param connecter The connecter of the request.
 */
void ClientNetworkCoordinatorSocketHandler::ConnectToServer(const std::string &invite_code, TCPServerConnecter *connecter)
{
	assert(StrStartsWith(invite_code, "+"));

	if (this->connecter_pre.find(invite_code) != this->connecter_pre.end()) {
		/* If someone is hammering the refresh key, one can sent out two
		 * requests for the same invite code. There isn't really a great way
		 * of handling this, so just ignore this request. */
		connecter->SetFailure();
		return;
	}

	/* Initially we store based on invite code; on first reply we know the
	 * token, and will start using that key instead. */
	this->connecter_pre[invite_code] = connecter;

	this->Connect();

	Packet *p = new Packet(PACKET_COORDINATOR_CLIENT_CONNECT);
	p->Send_uint8(NETWORK_COORDINATOR_VERSION);
	p->Send_string(invite_code);

	this->SendPacket(p);
}

/**
 * Callback from a Connecter to let the Game Coordinator know the connection failed.
 * @param token Token of the connecter that failed.
 * @param tracking_number Tracking number of the connecter that failed.
 */
void ClientNetworkCoordinatorSocketHandler::ConnectFailure(const std::string &token, uint8 tracking_number)
{
	/* Connecter will destroy itself. */
	this->game_connecter = nullptr;

	Packet *p = new Packet(PACKET_COORDINATOR_SERCLI_CONNECT_FAILED);
	p->Send_uint8(NETWORK_COORDINATOR_VERSION);
	p->Send_string(token);
	p->Send_uint8(tracking_number);

	this->SendPacket(p);

	/* We do not close the associated connecter here yet, as the
	 * Game Coordinator might have other methods of connecting available. */
}

/**
 * Callback from a Connecter to let the Game Coordinator know the connection
 * to the game server is established.
 * @param token Token of the connecter that succeeded.
 * @param sock The socket that the connecter can now use.
 */
void ClientNetworkCoordinatorSocketHandler::ConnectSuccess(const std::string &token, SOCKET sock, NetworkAddress &address)
{
	/* Connecter will destroy itself. */
	this->game_connecter = nullptr;

	if (_network_server) {
		if (!ServerNetworkGameSocketHandler::ValidateClient(sock, address)) return;
		Debug(net, 3, "[{}] Client connected from {} on frame {}", ServerNetworkGameSocketHandler::GetName(), address.GetHostname(), _frame_counter);
		ServerNetworkGameSocketHandler::AcceptConnection(sock, address);
	} else {
		/* The client informs the Game Coordinator about the success. The server
		 * doesn't have to, as it is implied by the client telling. */
		Packet *p = new Packet(PACKET_COORDINATOR_CLIENT_CONNECTED);
		p->Send_uint8(NETWORK_COORDINATOR_VERSION);
		p->Send_string(token);
		this->SendPacket(p);

		/* Find the connecter; it can happen it no longer exist, in cases where
		 * we aborted the connect but the Game Coordinator was already in the
		 * processes of connecting us. */
		auto connecter_it = this->connecter.find(token);
		if (connecter_it != this->connecter.end()) {
			connecter_it->second.second->SetConnected(sock);
			this->connecter.erase(connecter_it);
		}
	}

	/* Close all remaining connections. */
	this->CloseToken(token);
}

/**
 * Callback from the STUN connecter to inform the Game Coordinator about the
 * result of the STUN.
 *
 * This helps the Game Coordinator not to wait for a timeout on its end, but
 * rather react as soon as the client/server knows the result.
 */
void ClientNetworkCoordinatorSocketHandler::StunResult(const std::string &token, uint8 family, bool result)
{
	Packet *p = new Packet(PACKET_COORDINATOR_SERCLI_STUN_RESULT);
	p->Send_uint8(NETWORK_COORDINATOR_VERSION);
	p->Send_string(token);
	p->Send_uint8(family);
	p->Send_bool(result);
	this->SendPacket(p);
}

/**
 * Close the STUN handler.
 * @param token The token used for the STUN handlers.
 * @param family The family of STUN handlers to close. AF_UNSPEC to close all STUN handlers for this token.
 */
void ClientNetworkCoordinatorSocketHandler::CloseStunHandler(const std::string &token, uint8 family)
{
	auto stun_it = this->stun_handlers.find(token);
	if (stun_it == this->stun_handlers.end()) return;

	if (family == AF_UNSPEC) {
		for (auto &[family, stun_handler] : stun_it->second) {
			stun_handler->CloseConnection();
			stun_handler->CloseSocket();
		}

		this->stun_handlers.erase(stun_it);
	} else {
		auto family_it = stun_it->second.find(family);
		if (family_it == stun_it->second.end()) return;

		family_it->second->CloseConnection();
		family_it->second->CloseSocket();

		stun_it->second.erase(family_it);
	}
}

/**
 * Close the TURN handler.
 * @param token The token used for the TURN handler.
 */
void ClientNetworkCoordinatorSocketHandler::CloseTurnHandler(const std::string &token)
{
	CloseWindowByClass(WC_NETWORK_ASK_RELAY);

	auto turn_it = this->turn_handlers.find(token);
	if (turn_it == this->turn_handlers.end()) return;

	turn_it->second->CloseConnection();
	turn_it->second->CloseSocket();

	/* We don't remove turn_handler here, as we can be called from within that
	 * turn_handler instance, so our object cannot be free'd yet. Instead, we
	 * check later if the connection is closed, and free the object then. */
}

/**
 * Close everything related to this connection token.
 * @param token The connection token to close.
 */
void ClientNetworkCoordinatorSocketHandler::CloseToken(const std::string &token)
{
	/* Close all remaining STUN / TURN connections. */
	this->CloseStunHandler(token);
	this->CloseTurnHandler(token);

	/* Close the caller of the connection attempt. */
	auto connecter_it = this->connecter.find(token);
	if (connecter_it != this->connecter.end()) {
		connecter_it->second.second->SetFailure();
		this->connecter.erase(connecter_it);
	}
}

/**
 * Close all pending connection tokens.
 */
void ClientNetworkCoordinatorSocketHandler::CloseAllConnections()
{
	/* Ensure all other pending connection attempts are also killed. */
	if (this->game_connecter != nullptr) {
		this->game_connecter->Kill();
		this->game_connecter = nullptr;
	}

	/* Mark any pending connecters as failed. */
	for (auto &[token, it] : this->connecter) {
		this->CloseStunHandler(token);
		this->CloseTurnHandler(token);
		it.second->SetFailure();

		/* Inform the Game Coordinator he can stop trying to connect us to the server. */
		this->ConnectFailure(token, 0);
	}
	this->stun_handlers.clear();
	this->turn_handlers.clear();
	this->connecter.clear();

	/* Also close any pending invite-code requests. */
	for (auto &[invite_code, it] : this->connecter_pre) {
		it->SetFailure();
	}
	this->connecter_pre.clear();
}

/**
 * Check whether we received/can send some data from/to the Game Coordinator server and
 * when that's the case handle it appropriately.
 */
void ClientNetworkCoordinatorSocketHandler::SendReceive()
{
	/* Private games are not listed via the Game Coordinator. */
	if (_network_server && _settings_client.network.server_game_type == SERVER_GAME_TYPE_LOCAL) {
		if (this->sock != INVALID_SOCKET) {
			this->CloseConnection();
		}
		return;
	}

	static int last_attempt_backoff = 1;
	static bool first_reconnect = true;

	if (this->sock == INVALID_SOCKET) {
		static std::chrono::steady_clock::time_point last_attempt = {};

		/* Don't auto-reconnect when we are not a server. */
		if (!_network_server) return;
		/* Don't reconnect if we are connecting. */
		if (this->connecting) return;
		/* Throttle how often we try to reconnect. */
		if (std::chrono::steady_clock::now() < last_attempt + std::chrono::seconds(1) * last_attempt_backoff) return;

		last_attempt = std::chrono::steady_clock::now();
		/* Delay reconnecting with up to 32 seconds. */
		if (last_attempt_backoff < 32) {
			last_attempt_backoff *= 2;
		}

		/* Do not reconnect on the first attempt, but only initialize the
		 * last_attempt variables.  Otherwise after an outage all servers
		 * reconnect at the same time, potentially overwhelming the
		 * Game Coordinator. */
		if (first_reconnect) {
			first_reconnect = false;
			return;
		}

		Debug(net, 1, "Connection with Game Coordinator lost; reconnecting...");
		this->Register();
		return;
	}

	last_attempt_backoff = 1;
	first_reconnect = true;

	if (_network_server && _network_server_connection_type != CONNECTION_TYPE_UNKNOWN && std::chrono::steady_clock::now() > this->next_update) {
		this->SendServerUpdate();
	}

	if (!_network_server && std::chrono::steady_clock::now() > this->last_activity + IDLE_TIMEOUT) {
		this->CloseConnection();
		return;
	}

	if (this->CanSendReceive()) {
		if (this->ReceivePackets()) {
			this->last_activity = std::chrono::steady_clock::now();
		}
	}

	this->SendPackets();

	for (const auto &[token, families] : this->stun_handlers) {
		for (const auto &[family, stun_handler] : families) {
			stun_handler->SendReceive();
		}
	}

	/* Check for handlers that are not connecting nor connected. Destroy those objects. */
	for (auto turn_it = this->turn_handlers.begin(); turn_it != this->turn_handlers.end(); /* nothing */) {
		if (turn_it->second->connect_started && turn_it->second->connecter == nullptr && !turn_it->second->IsConnected()) {
			turn_it = this->turn_handlers.erase(turn_it);
		} else {
			turn_it++;
		}
	}

	for (const auto &[token, turn_handler] : this->turn_handlers) {
		turn_handler->SendReceive();
	}
}