summaryrefslogtreecommitdiff
path: root/src/network/network_client.cpp
blob: bc5f24ac38c80033fe0cb72b4a86bbab861b22ff (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
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
/*
 * 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_client.cpp Client part of the network protocol. */

#include "../stdafx.h"
#include "network_gui.h"
#include "../saveload/saveload.h"
#include "../saveload/saveload_filter.h"
#include "../command_func.h"
#include "../console_func.h"
#include "../strings_func.h"
#include "../window_func.h"
#include "../company_func.h"
#include "../company_base.h"
#include "../company_gui.h"
#include "../core/random_func.hpp"
#include "../date_func.h"
#include "../gfx_func.h"
#include "../error.h"
#include "../rev.h"
#include "network.h"
#include "network_base.h"
#include "network_client.h"
#include "network_gamelist.h"
#include "../core/backup_type.hpp"
#include "../thread.h"

#include "table/strings.h"

#include "../safeguards.h"

/* This file handles all the client-commands */

/** Read some packets, and when do use that data as initial load filter. */
struct PacketReader : LoadFilter {
	static const size_t CHUNK = 32 * 1024;  ///< 32 KiB chunks of memory.

	std::vector<byte *> blocks;             ///< Buffer with blocks of allocated memory.
	byte *buf;                              ///< Buffer we're going to write to/read from.
	byte *bufe;                             ///< End of the buffer we write to/read from.
	byte **block;                           ///< The block we're reading from/writing to.
	size_t written_bytes;                   ///< The total number of bytes we've written.
	size_t read_bytes;                      ///< The total number of read bytes.

	/** Initialise everything. */
	PacketReader() : LoadFilter(nullptr), buf(nullptr), bufe(nullptr), block(nullptr), written_bytes(0), read_bytes(0)
	{
	}

	~PacketReader() override
	{
		for (auto p : this->blocks) {
			free(p);
		}
	}

	/**
	 * Simple wrapper around fwrite to be able to pass it to Packet's TransferOut.
	 * @param destination The reader to add the data to.
	 * @param source      The buffer to read data from.
	 * @param amount      The number of bytes to copy.
	 * @return The number of bytes that were copied.
	 */
	static inline ssize_t TransferOutMemCopy(PacketReader *destination, const char *source, size_t amount)
	{
		memcpy(destination->buf, source, amount);
		destination->buf += amount;
		destination->written_bytes += amount;
		return amount;
	}

	/**
	 * Add a packet to this buffer.
	 * @param p The packet to add.
	 */
	void AddPacket(Packet *p)
	{
		assert(this->read_bytes == 0);
		p->TransferOutWithLimit(TransferOutMemCopy, this->bufe - this->buf, this);

		/* Did everything fit in the current chunk, then we're done. */
		if (p->RemainingBytesToTransfer() == 0) return;

		/* Allocate a new chunk and add the remaining data. */
		this->blocks.push_back(this->buf = CallocT<byte>(CHUNK));
		this->bufe = this->buf + CHUNK;

		p->TransferOutWithLimit(TransferOutMemCopy, this->bufe - this->buf, this);
	}

	size_t Read(byte *rbuf, size_t size) override
	{
		/* Limit the amount to read to whatever we still have. */
		size_t ret_size = size = std::min(this->written_bytes - this->read_bytes, size);
		this->read_bytes += ret_size;
		const byte *rbufe = rbuf + ret_size;

		while (rbuf != rbufe) {
			if (this->buf == this->bufe) {
				this->buf = *this->block++;
				this->bufe = this->buf + CHUNK;
			}

			size_t to_write = std::min(this->bufe - this->buf, rbufe - rbuf);
			memcpy(rbuf, this->buf, to_write);
			rbuf += to_write;
			this->buf += to_write;
		}

		return ret_size;
	}

	void Reset() override
	{
		this->read_bytes = 0;

		this->block = this->blocks.data();
		this->buf   = *this->block++;
		this->bufe  = this->buf + CHUNK;
	}
};


/**
 * Create an emergency savegame when the network connection is lost.
 */
void ClientNetworkEmergencySave()
{
	static FiosNumberedSaveName _netsave_ctr("netsave");
	DoAutoOrNetsave(_netsave_ctr);
}


/**
 * Create a new socket for the client side of the game connection.
 * @param s The socket to connect with.
 */
ClientNetworkGameSocketHandler::ClientNetworkGameSocketHandler(SOCKET s, const std::string &connection_string) : NetworkGameSocketHandler(s), connection_string(connection_string), savegame(nullptr), status(STATUS_INACTIVE)
{
	assert(ClientNetworkGameSocketHandler::my_client == nullptr);
	ClientNetworkGameSocketHandler::my_client = this;
}

/** Clear whatever we assigned. */
ClientNetworkGameSocketHandler::~ClientNetworkGameSocketHandler()
{
	assert(ClientNetworkGameSocketHandler::my_client == this);
	ClientNetworkGameSocketHandler::my_client = nullptr;

	delete this->savegame;
	delete this->GetInfo();
}

NetworkRecvStatus ClientNetworkGameSocketHandler::CloseConnection(NetworkRecvStatus status)
{
	assert(status != NETWORK_RECV_STATUS_OKAY);
	assert(this->sock != INVALID_SOCKET);

	if (!this->HasClientQuit()) {
		Debug(net, 3, "Closed client connection {}", this->client_id);

		this->SendPackets(true);

		/* Wait a number of ticks so our leave message can reach the server.
		* This is especially needed for Windows servers as they seem to get
		* the "socket is closed" message before receiving our leave message,
		* which would trigger the server to close the connection as well. */
		CSleep(3 * MILLISECONDS_PER_TICK);
	}

	delete this;

	return status;
}

/**
 * Handle an error coming from the client side.
 * @param res The "error" that happened.
 */
void ClientNetworkGameSocketHandler::ClientError(NetworkRecvStatus res)
{
	/* First, send a CLIENT_ERROR to the server, so it knows we are
	 *  disconnected (and why!) */
	NetworkErrorCode errorno;

	/* We just want to close the connection.. */
	if (res == NETWORK_RECV_STATUS_CLOSE_QUERY) {
		this->NetworkSocketHandler::MarkClosed();
		this->CloseConnection(res);
		_networking = false;

		CloseWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);
		return;
	}

	switch (res) {
		case NETWORK_RECV_STATUS_DESYNC:          errorno = NETWORK_ERROR_DESYNC; break;
		case NETWORK_RECV_STATUS_SAVEGAME:        errorno = NETWORK_ERROR_SAVEGAME_FAILED; break;
		case NETWORK_RECV_STATUS_NEWGRF_MISMATCH: errorno = NETWORK_ERROR_NEWGRF_MISMATCH; break;
		default:                                  errorno = NETWORK_ERROR_GENERAL; break;
	}

	if (res == NETWORK_RECV_STATUS_SERVER_ERROR || res == NETWORK_RECV_STATUS_SERVER_FULL ||
			res == NETWORK_RECV_STATUS_SERVER_BANNED) {
		/* This means the server closed the connection. Emergency save is
		 * already created if this was appropriate during handling of the
		 * disconnect. */
		this->CloseConnection(res);
	} else {
		/* This means we as client made a boo-boo. */
		SendError(errorno);

		/* Close connection before we make an emergency save, as the save can
		 * take a bit of time; better that the server doesn't stall while we
		 * are doing the save, and already disconnects us. */
		this->CloseConnection(res);
		ClientNetworkEmergencySave();
	}

	_switch_mode = SM_MENU;
	_networking = false;
}


/**
 * Check whether we received/can send some data from/to the server and
 * when that's the case handle it appropriately.
 * @return true when everything went okay.
 */
/* static */ bool ClientNetworkGameSocketHandler::Receive()
{
	if (my_client->CanSendReceive()) {
		NetworkRecvStatus res = my_client->ReceivePackets();
		if (res != NETWORK_RECV_STATUS_OKAY) {
			/* The client made an error of which we can not recover.
			 * Close the connection and drop back to the main menu. */
			my_client->ClientError(res);
			return false;
		}
	}
	return _networking;
}

/** Send the packets of this socket handler. */
/* static */ void ClientNetworkGameSocketHandler::Send()
{
	my_client->SendPackets();
	if (my_client != nullptr) my_client->CheckConnection();
}

/**
 * Actual game loop for the client.
 * @return Whether everything went okay, or not.
 */
/* static */ bool ClientNetworkGameSocketHandler::GameLoop()
{
	_frame_counter++;

	NetworkExecuteLocalCommandQueue();

	extern void StateGameLoop();
	StateGameLoop();

	/* Check if we are in sync! */
	if (_sync_frame != 0) {
		if (_sync_frame == _frame_counter) {
#ifdef NETWORK_SEND_DOUBLE_SEED
			if (_sync_seed_1 != _random.state[0] || _sync_seed_2 != _random.state[1]) {
#else
			if (_sync_seed_1 != _random.state[0]) {
#endif
				ShowNetworkError(STR_NETWORK_ERROR_DESYNC);
				Debug(desync, 1, "sync_err: {:08x}; {:02x}", _date, _date_fract);
				Debug(net, 0, "Sync error detected");
				my_client->ClientError(NETWORK_RECV_STATUS_DESYNC);
				return false;
			}

			/* If this is the first time we have a sync-frame, we
			 *   need to let the server know that we are ready and at the same
			 *   frame as it is.. so we can start playing! */
			if (_network_first_time) {
				_network_first_time = false;
				SendAck();
			}

			_sync_frame = 0;
		} else if (_sync_frame < _frame_counter) {
			Debug(net, 1, "Missed frame for sync-test: {} / {}", _sync_frame, _frame_counter);
			_sync_frame = 0;
		}
	}

	return true;
}


/** Our client's connection. */
ClientNetworkGameSocketHandler * ClientNetworkGameSocketHandler::my_client = nullptr;

/** Last frame we performed an ack. */
static uint32 last_ack_frame;

/** One bit of 'entropy' used to generate a salt for the company passwords. */
static uint32 _password_game_seed;
/** The other bit of 'entropy' used to generate a salt for the company passwords. */
static std::string _password_server_id;

/** Maximum number of companies of the currently joined server. */
static uint8 _network_server_max_companies;
/** The current name of the server you are on. */
std::string _network_server_name;

/** Information about the game to join to. */
NetworkJoinInfo _network_join;

/** Make sure the server ID length is the same as a md5 hash. */
static_assert(NETWORK_SERVER_ID_LENGTH == 16 * 2 + 1);

/***********
 * Sending functions
 *   DEF_CLIENT_SEND_COMMAND has no parameters
 ************/

/** Tell the server we would like to join. */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendJoin()
{
	my_client->status = STATUS_JOIN;
	_network_join_status = NETWORK_JOIN_STATUS_AUTHORIZING;
	SetWindowDirty(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	Packet *p = new Packet(PACKET_CLIENT_JOIN);
	p->Send_string(GetNetworkRevisionString());
	p->Send_uint32(_openttd_newgrf_version);
	p->Send_string(_settings_client.network.client_name); // Client name
	p->Send_uint8 (_network_join.company);     // PlayAs
	p->Send_uint8 (0); // Used to be language
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/** Tell the server we got all the NewGRFs. */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendNewGRFsOk()
{
	Packet *p = new Packet(PACKET_CLIENT_NEWGRFS_CHECKED);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Set the game password as requested.
 * @param password The game password.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendGamePassword(const std::string &password)
{
	Packet *p = new Packet(PACKET_CLIENT_GAME_PASSWORD);
	p->Send_string(password);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Set the company password as requested.
 * @param password The company password.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendCompanyPassword(const std::string &password)
{
	Packet *p = new Packet(PACKET_CLIENT_COMPANY_PASSWORD);
	p->Send_string(GenerateCompanyPasswordHash(password, _password_server_id, _password_game_seed));
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/** Request the map from the server. */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendGetMap()
{
	my_client->status = STATUS_MAP_WAIT;

	Packet *p = new Packet(PACKET_CLIENT_GETMAP);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/** Tell the server we received the complete map. */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendMapOk()
{
	my_client->status = STATUS_ACTIVE;

	Packet *p = new Packet(PACKET_CLIENT_MAP_OK);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/** Send an acknowledgement from the server's ticks. */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendAck()
{
	Packet *p = new Packet(PACKET_CLIENT_ACK);

	p->Send_uint32(_frame_counter);
	p->Send_uint8 (my_client->token);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Send a command to the server.
 * @param cp The command to send.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendCommand(const CommandPacket *cp)
{
	Packet *p = new Packet(PACKET_CLIENT_COMMAND);
	my_client->NetworkGameSocketHandler::SendCommand(p, cp);

	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/** Send a chat-packet over the network */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendChat(NetworkAction action, DestType type, int dest, const std::string &msg, int64 data)
{
	Packet *p = new Packet(PACKET_CLIENT_CHAT);

	p->Send_uint8 (action);
	p->Send_uint8 (type);
	p->Send_uint32(dest);
	p->Send_string(msg);
	p->Send_uint64(data);

	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/** Send an error-packet over the network */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendError(NetworkErrorCode errorno)
{
	Packet *p = new Packet(PACKET_CLIENT_ERROR);

	p->Send_uint8(errorno);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Tell the server that we like to change the password of the company.
 * @param password The new password.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendSetPassword(const std::string &password)
{
	Packet *p = new Packet(PACKET_CLIENT_SET_PASSWORD);

	p->Send_string(GenerateCompanyPasswordHash(password, _password_server_id, _password_game_seed));
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Tell the server that we like to change the name of the client.
 * @param name The new name.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendSetName(const std::string &name)
{
	Packet *p = new Packet(PACKET_CLIENT_SET_NAME);

	p->Send_string(name);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Tell the server we would like to quit.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendQuit()
{
	Packet *p = new Packet(PACKET_CLIENT_QUIT);

	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Send a console command.
 * @param pass The password for the remote command.
 * @param command The actual command.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendRCon(const std::string &pass, const std::string &command)
{
	Packet *p = new Packet(PACKET_CLIENT_RCON);
	p->Send_string(pass);
	p->Send_string(command);
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Ask the server to move us.
 * @param company The company to move to.
 * @param password The password of the company to move to.
 */
NetworkRecvStatus ClientNetworkGameSocketHandler::SendMove(CompanyID company, const std::string &password)
{
	Packet *p = new Packet(PACKET_CLIENT_MOVE);
	p->Send_uint8(company);
	p->Send_string(GenerateCompanyPasswordHash(password, _password_server_id, _password_game_seed));
	my_client->SendPacket(p);
	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Check whether the client is actually connected (and in the game).
 * @return True when the client is connected.
 */
bool ClientNetworkGameSocketHandler::IsConnected()
{
	return my_client != nullptr && my_client->status == STATUS_ACTIVE;
}


/***********
 * Receiving functions
 *   DEF_CLIENT_RECEIVE_COMMAND has parameter: Packet *p
 ************/

extern bool SafeLoad(const std::string &filename, SaveLoadOperation fop, DetailedFileType dft, GameMode newgm, Subdirectory subdir, struct LoadFilter *lf = nullptr);

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_FULL(Packet *p)
{
	/* We try to join a server which is full */
	ShowErrorMessage(STR_NETWORK_ERROR_SERVER_FULL, INVALID_STRING_ID, WL_CRITICAL);
	CloseWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	return NETWORK_RECV_STATUS_SERVER_FULL;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_BANNED(Packet *p)
{
	/* We try to join a server where we are banned */
	ShowErrorMessage(STR_NETWORK_ERROR_SERVER_BANNED, INVALID_STRING_ID, WL_CRITICAL);
	CloseWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	return NETWORK_RECV_STATUS_SERVER_BANNED;
}

/* This packet contains info about the client (playas and name)
 *  as client we save this in NetworkClientInfo, linked via 'client_id'
 *  which is always an unique number on a server. */
NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_CLIENT_INFO(Packet *p)
{
	NetworkClientInfo *ci;
	ClientID client_id = (ClientID)p->Recv_uint32();
	CompanyID playas = (CompanyID)p->Recv_uint8();

	std::string name = p->Recv_string(NETWORK_NAME_LENGTH);

	if (this->status < STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CLIENT_QUIT;
	/* The server validates the name when receiving it from clients, so when it is wrong
	 * here something went really wrong. In the best case the packet got malformed on its
	 * way too us, in the worst case the server is broken or compromised. */
	if (!NetworkIsValidClientName(name)) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	ci = NetworkClientInfo::GetByClientID(client_id);
	if (ci != nullptr) {
		if (playas == ci->client_playas && name.compare(ci->client_name) != 0) {
			/* Client name changed, display the change */
			NetworkTextMessage(NETWORK_ACTION_NAME_CHANGE, CC_DEFAULT, false, ci->client_name, name);
		} else if (playas != ci->client_playas) {
			/* The client changed from client-player..
			 * Do not display that for now */
		}

		/* Make sure we're in the company the server tells us to be in,
		 * for the rare case that we get moved while joining. */
		if (client_id == _network_own_client_id) SetLocalCompany(!Company::IsValidID(playas) ? COMPANY_SPECTATOR : playas);

		ci->client_playas = playas;
		ci->client_name = name;

		InvalidateWindowData(WC_CLIENT_LIST, 0);

		return NETWORK_RECV_STATUS_OKAY;
	}

	/* There are at most as many ClientInfo as ClientSocket objects in a
	 * server. Having more info than a server can have means something
	 * has gone wrong somewhere, i.e. the server has more info than it
	 * has actual clients. That means the server is feeding us an invalid
	 * state. So, bail out! This server is broken. */
	if (!NetworkClientInfo::CanAllocateItem()) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	/* We don't have this client_id yet, find an empty client_id, and put the data there */
	ci = new NetworkClientInfo(client_id);
	ci->client_playas = playas;
	if (client_id == _network_own_client_id) this->SetInfo(ci);

	ci->client_name = name;

	InvalidateWindowData(WC_CLIENT_LIST, 0);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_ERROR(Packet *p)
{
	static const StringID network_error_strings[] = {
		STR_NETWORK_ERROR_LOSTCONNECTION,      // NETWORK_ERROR_GENERAL
		STR_NETWORK_ERROR_LOSTCONNECTION,      // NETWORK_ERROR_DESYNC
		STR_NETWORK_ERROR_LOSTCONNECTION,      // NETWORK_ERROR_SAVEGAME_FAILED
		STR_NETWORK_ERROR_LOSTCONNECTION,      // NETWORK_ERROR_CONNECTION_LOST
		STR_NETWORK_ERROR_LOSTCONNECTION,      // NETWORK_ERROR_ILLEGAL_PACKET
		STR_NETWORK_ERROR_LOSTCONNECTION,      // NETWORK_ERROR_NEWGRF_MISMATCH
		STR_NETWORK_ERROR_SERVER_ERROR,        // NETWORK_ERROR_NOT_AUTHORIZED
		STR_NETWORK_ERROR_SERVER_ERROR,        // NETWORK_ERROR_NOT_EXPECTED
		STR_NETWORK_ERROR_WRONG_REVISION,      // NETWORK_ERROR_WRONG_REVISION
		STR_NETWORK_ERROR_LOSTCONNECTION,      // NETWORK_ERROR_NAME_IN_USE
		STR_NETWORK_ERROR_WRONG_PASSWORD,      // NETWORK_ERROR_WRONG_PASSWORD
		STR_NETWORK_ERROR_SERVER_ERROR,        // NETWORK_ERROR_COMPANY_MISMATCH
		STR_NETWORK_ERROR_KICKED,              // NETWORK_ERROR_KICKED
		STR_NETWORK_ERROR_CHEATER,             // NETWORK_ERROR_CHEATER
		STR_NETWORK_ERROR_SERVER_FULL,         // NETWORK_ERROR_FULL
		STR_NETWORK_ERROR_TOO_MANY_COMMANDS,   // NETWORK_ERROR_TOO_MANY_COMMANDS
		STR_NETWORK_ERROR_TIMEOUT_PASSWORD,    // NETWORK_ERROR_TIMEOUT_PASSWORD
		STR_NETWORK_ERROR_TIMEOUT_COMPUTER,    // NETWORK_ERROR_TIMEOUT_COMPUTER
		STR_NETWORK_ERROR_TIMEOUT_MAP,         // NETWORK_ERROR_TIMEOUT_MAP
		STR_NETWORK_ERROR_TIMEOUT_JOIN,        // NETWORK_ERROR_TIMEOUT_JOIN
		STR_NETWORK_ERROR_INVALID_CLIENT_NAME, // NETWORK_ERROR_INVALID_CLIENT_NAME
	};
	static_assert(lengthof(network_error_strings) == NETWORK_ERROR_END);

	NetworkErrorCode error = (NetworkErrorCode)p->Recv_uint8();

	StringID err = STR_NETWORK_ERROR_LOSTCONNECTION;
	if (error < (ptrdiff_t)lengthof(network_error_strings)) err = network_error_strings[error];
	/* In case of kicking a client, we assume there is a kick message in the packet if we can read one byte */
	if (error == NETWORK_ERROR_KICKED && p->CanReadFromPacket(1)) {
		std::string kick_msg = p->Recv_string(NETWORK_CHAT_LENGTH);
		SetDParamStr(0, kick_msg);
		ShowErrorMessage(err, STR_NETWORK_ERROR_KICK_MESSAGE, WL_CRITICAL);
	} else {
		ShowErrorMessage(err, INVALID_STRING_ID, WL_CRITICAL);
	}

	/* Perform an emergency save if we had already entered the game */
	if (this->status == STATUS_ACTIVE) ClientNetworkEmergencySave();

	CloseWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	return NETWORK_RECV_STATUS_SERVER_ERROR;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_CHECK_NEWGRFS(Packet *p)
{
	if (this->status != STATUS_JOIN) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	uint grf_count = p->Recv_uint8();
	NetworkRecvStatus ret = NETWORK_RECV_STATUS_OKAY;

	/* Check all GRFs */
	for (; grf_count > 0; grf_count--) {
		GRFIdentifier c;
		DeserializeGRFIdentifier(p, &c);

		/* Check whether we know this GRF */
		const GRFConfig *f = FindGRFConfig(c.grfid, FGCM_EXACT, c.md5sum);
		if (f == nullptr) {
			/* We do not know this GRF, bail out of initialization */
			char buf[sizeof(c.md5sum) * 2 + 1];
			md5sumToString(buf, lastof(buf), c.md5sum);
			Debug(grf, 0, "NewGRF {:08X} not found; checksum {}", BSWAP32(c.grfid), buf);
			ret = NETWORK_RECV_STATUS_NEWGRF_MISMATCH;
		}
	}

	if (ret == NETWORK_RECV_STATUS_OKAY) {
		/* Start receiving the map */
		return SendNewGRFsOk();
	}

	/* NewGRF mismatch, bail out */
	ShowErrorMessage(STR_NETWORK_ERROR_NEWGRF_MISMATCH, INVALID_STRING_ID, WL_CRITICAL);
	return ret;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_NEED_GAME_PASSWORD(Packet *p)
{
	if (this->status < STATUS_JOIN || this->status >= STATUS_AUTH_GAME) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	this->status = STATUS_AUTH_GAME;

	if (!_network_join.server_password.empty()) {
		return SendGamePassword(_network_join.server_password);
	}

	ShowNetworkNeedPassword(NETWORK_GAME_PASSWORD);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_NEED_COMPANY_PASSWORD(Packet *p)
{
	if (this->status < STATUS_JOIN || this->status >= STATUS_AUTH_COMPANY) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	this->status = STATUS_AUTH_COMPANY;

	_password_game_seed = p->Recv_uint32();
	_password_server_id = p->Recv_string(NETWORK_SERVER_ID_LENGTH);
	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	if (!_network_join.company_password.empty()) {
		return SendCompanyPassword(_network_join.company_password);
	}

	ShowNetworkNeedPassword(NETWORK_COMPANY_PASSWORD);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_WELCOME(Packet *p)
{
	if (this->status < STATUS_JOIN || this->status >= STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	this->status = STATUS_AUTHORIZED;

	_network_own_client_id = (ClientID)p->Recv_uint32();

	/* Initialize the password hash salting variables, even if they were previously. */
	_password_game_seed = p->Recv_uint32();
	_password_server_id = p->Recv_string(NETWORK_SERVER_ID_LENGTH);

	/* Start receiving the map */
	return SendGetMap();
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_WAIT(Packet *p)
{
	/* We set the internal wait state when requesting the map. */
	if (this->status != STATUS_MAP_WAIT) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	/* But... only now we set the join status to waiting, instead of requesting. */
	_network_join_status = NETWORK_JOIN_STATUS_WAITING;
	_network_join_waiting = p->Recv_uint8();
	SetWindowDirty(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_MAP_BEGIN(Packet *p)
{
	if (this->status < STATUS_AUTHORIZED || this->status >= STATUS_MAP) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	this->status = STATUS_MAP;

	if (this->savegame != nullptr) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	this->savegame = new PacketReader();

	_frame_counter = _frame_counter_server = _frame_counter_max = p->Recv_uint32();

	_network_join_bytes = 0;
	_network_join_bytes_total = 0;

	_network_join_status = NETWORK_JOIN_STATUS_DOWNLOADING;
	SetWindowDirty(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_MAP_SIZE(Packet *p)
{
	if (this->status != STATUS_MAP) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	if (this->savegame == nullptr) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	_network_join_bytes_total = p->Recv_uint32();
	SetWindowDirty(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_MAP_DATA(Packet *p)
{
	if (this->status != STATUS_MAP) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	if (this->savegame == nullptr) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	/* We are still receiving data, put it to the file */
	this->savegame->AddPacket(p);

	_network_join_bytes = (uint32)this->savegame->written_bytes;
	SetWindowDirty(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_MAP_DONE(Packet *p)
{
	if (this->status != STATUS_MAP) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	if (this->savegame == nullptr) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	_network_join_status = NETWORK_JOIN_STATUS_PROCESSING;
	SetWindowDirty(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);

	/*
	 * Make sure everything is set for reading.
	 *
	 * We need the local copy and reset this->savegame because when
	 * loading fails the network gets reset upon loading the intro
	 * game, which would cause us to free this->savegame twice.
	 */
	LoadFilter *lf = this->savegame;
	this->savegame = nullptr;
	lf->Reset();

	/* The map is done downloading, load it */
	ClearErrorMessages();
	bool load_success = SafeLoad({}, SLO_LOAD, DFT_GAME_FILE, GM_NORMAL, NO_DIRECTORY, lf);

	/* Long savegame loads shouldn't affect the lag calculation! */
	this->last_packet = std::chrono::steady_clock::now();

	if (!load_success) {
		CloseWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_JOIN);
		ShowErrorMessage(STR_NETWORK_ERROR_SAVEGAMEERROR, INVALID_STRING_ID, WL_CRITICAL);
		return NETWORK_RECV_STATUS_SAVEGAME;
	}
	/* If the savegame has successfully loaded, ALL windows have been removed,
	 * only toolbar/statusbar and gamefield are visible */

	/* Say we received the map and loaded it correctly! */
	SendMapOk();

	ShowClientList();

	/* New company/spectator (invalid company) or company we want to join is not active
	 * Switch local company to spectator and await the server's judgement */
	if (_network_join.company == COMPANY_NEW_COMPANY || !Company::IsValidID(_network_join.company)) {
		SetLocalCompany(COMPANY_SPECTATOR);

		if (_network_join.company != COMPANY_SPECTATOR) {
			/* We have arrived and ready to start playing; send a command to make a new company;
			 * the server will give us a client-id and let us in */
			_network_join_status = NETWORK_JOIN_STATUS_REGISTERING;
			ShowJoinStatusWindow();
			NetworkSendCommand(0, CCA_NEW, 0, CMD_COMPANY_CTRL, nullptr, {}, _local_company);
		}
	} else {
		/* take control over an existing company */
		SetLocalCompany(_network_join.company);
	}

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_FRAME(Packet *p)
{
	if (this->status != STATUS_ACTIVE) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	_frame_counter_server = p->Recv_uint32();
	_frame_counter_max = p->Recv_uint32();
#ifdef ENABLE_NETWORK_SYNC_EVERY_FRAME
	/* Test if the server supports this option
	 *  and if we are at the frame the server is */
#ifdef NETWORK_SEND_DOUBLE_SEED
	if (p->CanReadFromPacket(sizeof(uint32) + sizeof(uint32))) {
#else
	if (p->CanReadFromPacket(sizeof(uint32))) {
#endif
		_sync_frame = _frame_counter_server;
		_sync_seed_1 = p->Recv_uint32();
#ifdef NETWORK_SEND_DOUBLE_SEED
		_sync_seed_2 = p->Recv_uint32();
#endif
	}
#endif
	/* Receive the token. */
	if (p->CanReadFromPacket(sizeof(uint8))) this->token = p->Recv_uint8();

	Debug(net, 7, "Received FRAME {}", _frame_counter_server);

	/* Let the server know that we received this frame correctly
	 *  We do this only once per day, to save some bandwidth ;) */
	if (!_network_first_time && last_ack_frame < _frame_counter) {
		last_ack_frame = _frame_counter + DAY_TICKS;
		Debug(net, 7, "Sent ACK at {}", _frame_counter);
		SendAck();
	}

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_SYNC(Packet *p)
{
	if (this->status != STATUS_ACTIVE) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	_sync_frame = p->Recv_uint32();
	_sync_seed_1 = p->Recv_uint32();
#ifdef NETWORK_SEND_DOUBLE_SEED
	_sync_seed_2 = p->Recv_uint32();
#endif

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_COMMAND(Packet *p)
{
	if (this->status != STATUS_ACTIVE) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	CommandPacket cp;
	const char *err = this->ReceiveCommand(p, &cp);
	cp.frame    = p->Recv_uint32();
	cp.my_cmd   = p->Recv_bool();

	if (err != nullptr) {
		IConsolePrint(CC_WARNING, "Dropping server connection due to {}.", err);
		return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	}

	this->incoming_queue.Append(&cp);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_CHAT(Packet *p)
{
	if (this->status != STATUS_ACTIVE) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	std::string name;
	const NetworkClientInfo *ci = nullptr, *ci_to;

	NetworkAction action = (NetworkAction)p->Recv_uint8();
	ClientID client_id = (ClientID)p->Recv_uint32();
	bool self_send = p->Recv_bool();
	std::string msg = p->Recv_string(NETWORK_CHAT_LENGTH);
	int64 data = p->Recv_uint64();

	ci_to = NetworkClientInfo::GetByClientID(client_id);
	if (ci_to == nullptr) return NETWORK_RECV_STATUS_OKAY;

	/* Did we initiate the action locally? */
	if (self_send) {
		switch (action) {
			case NETWORK_ACTION_CHAT_CLIENT:
				/* For speaking to client we need the client-name */
				name = ci_to->client_name;
				ci = NetworkClientInfo::GetByClientID(_network_own_client_id);
				break;

			/* For speaking to company, we need the company-name */
			case NETWORK_ACTION_CHAT_COMPANY: {
				StringID str = Company::IsValidID(ci_to->client_playas) ? STR_COMPANY_NAME : STR_NETWORK_SPECTATORS;
				SetDParam(0, ci_to->client_playas);

				name = GetString(str);
				ci = NetworkClientInfo::GetByClientID(_network_own_client_id);
				break;
			}

			default: return NETWORK_RECV_STATUS_MALFORMED_PACKET;
		}
	} else {
		/* Display message from somebody else */
		name = ci_to->client_name;
		ci = ci_to;
	}

	if (ci != nullptr) {
		NetworkTextMessage(action, GetDrawStringCompanyColour(ci->client_playas), self_send, name, msg, data);
	}
	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_EXTERNAL_CHAT(Packet *p)
{
	if (this->status != STATUS_ACTIVE) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	std::string source = p->Recv_string(NETWORK_CHAT_LENGTH);
	TextColour colour = (TextColour)p->Recv_uint16();
	std::string user = p->Recv_string(NETWORK_CHAT_LENGTH);
	std::string msg = p->Recv_string(NETWORK_CHAT_LENGTH);

	if (!IsValidConsoleColour(colour)) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	NetworkTextMessage(NETWORK_ACTION_EXTERNAL_CHAT, colour, false, user, msg, 0, source);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_ERROR_QUIT(Packet *p)
{
	if (this->status < STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	ClientID client_id = (ClientID)p->Recv_uint32();

	NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(client_id);
	if (ci != nullptr) {
		NetworkTextMessage(NETWORK_ACTION_LEAVE, CC_DEFAULT, false, ci->client_name, "", GetNetworkErrorMsg((NetworkErrorCode)p->Recv_uint8()));
		delete ci;
	}

	InvalidateWindowData(WC_CLIENT_LIST, 0);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_QUIT(Packet *p)
{
	if (this->status < STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	ClientID client_id = (ClientID)p->Recv_uint32();

	NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(client_id);
	if (ci != nullptr) {
		NetworkTextMessage(NETWORK_ACTION_LEAVE, CC_DEFAULT, false, ci->client_name, "", STR_NETWORK_MESSAGE_CLIENT_LEAVING);
		delete ci;
	} else {
		Debug(net, 1, "Unknown client ({}) is leaving the game", client_id);
	}

	InvalidateWindowData(WC_CLIENT_LIST, 0);

	/* If we come here it means we could not locate the client.. strange :s */
	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_JOIN(Packet *p)
{
	if (this->status < STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	ClientID client_id = (ClientID)p->Recv_uint32();

	NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(client_id);
	if (ci != nullptr) {
		NetworkTextMessage(NETWORK_ACTION_JOIN, CC_DEFAULT, false, ci->client_name);
	}

	InvalidateWindowData(WC_CLIENT_LIST, 0);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_SHUTDOWN(Packet *p)
{
	/* Only when we're trying to join we really
	 * care about the server shutting down. */
	if (this->status >= STATUS_JOIN) {
		ShowErrorMessage(STR_NETWORK_MESSAGE_SERVER_SHUTDOWN, INVALID_STRING_ID, WL_CRITICAL);
	}

	if (this->status == STATUS_ACTIVE) ClientNetworkEmergencySave();

	return NETWORK_RECV_STATUS_SERVER_ERROR;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_NEWGAME(Packet *p)
{
	/* Only when we're trying to join we really
	 * care about the server shutting down. */
	if (this->status >= STATUS_JOIN) {
		/* To throttle the reconnects a bit, every clients waits its
		 * Client ID modulo 16. This way reconnects should be spread
		 * out a bit. */
		_network_reconnect = _network_own_client_id % 16;
		ShowErrorMessage(STR_NETWORK_MESSAGE_SERVER_REBOOT, INVALID_STRING_ID, WL_CRITICAL);
	}

	if (this->status == STATUS_ACTIVE) ClientNetworkEmergencySave();

	return NETWORK_RECV_STATUS_SERVER_ERROR;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_RCON(Packet *p)
{
	if (this->status < STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	TextColour colour_code = (TextColour)p->Recv_uint16();
	if (!IsValidConsoleColour(colour_code)) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	std::string rcon_out = p->Recv_string(NETWORK_RCONCOMMAND_LENGTH);

	IConsolePrint(colour_code, rcon_out);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_MOVE(Packet *p)
{
	if (this->status < STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	/* Nothing more in this packet... */
	ClientID client_id   = (ClientID)p->Recv_uint32();
	CompanyID company_id = (CompanyID)p->Recv_uint8();

	if (client_id == 0) {
		/* definitely an invalid client id, debug message and do nothing. */
		Debug(net, 1, "Received invalid client index = 0");
		return NETWORK_RECV_STATUS_MALFORMED_PACKET;
	}

	const NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(client_id);
	/* Just make sure we do not try to use a client_index that does not exist */
	if (ci == nullptr) return NETWORK_RECV_STATUS_OKAY;

	/* if not valid player, force spectator, else check player exists */
	if (!Company::IsValidID(company_id)) company_id = COMPANY_SPECTATOR;

	if (client_id == _network_own_client_id) {
		SetLocalCompany(company_id);
	}

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_CONFIG_UPDATE(Packet *p)
{
	if (this->status < STATUS_ACTIVE) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	_network_server_max_companies = p->Recv_uint8();
	_network_server_name = p->Recv_string(NETWORK_NAME_LENGTH);

	return NETWORK_RECV_STATUS_OKAY;
}

NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_COMPANY_UPDATE(Packet *p)
{
	if (this->status < STATUS_ACTIVE) return NETWORK_RECV_STATUS_MALFORMED_PACKET;

	_network_company_passworded = p->Recv_uint16();
	SetWindowClassesDirty(WC_COMPANY);

	return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Check the connection's state, i.e. is the connection still up?
 */
void ClientNetworkGameSocketHandler::CheckConnection()
{
	/* Only once we're authorized we can expect a steady stream of packets. */
	if (this->status < STATUS_AUTHORIZED) return;

	/* 5 seconds are roughly twice the server's "you're slow" threshold (1 game day). */
	std::chrono::steady_clock::duration lag = std::chrono::steady_clock::now() - this->last_packet;
	if (lag < std::chrono::seconds(5)) return;

	/* 20 seconds are (way) more than 4 game days after which
	 * the server will forcefully disconnect you. */
	if (lag > std::chrono::seconds(20)) {
		this->NetworkGameSocketHandler::CloseConnection();
		return;
	}

	/* Prevent showing the lag message every tick; just update it when needed. */
	static std::chrono::steady_clock::duration last_lag = {};
	if (std::chrono::duration_cast<std::chrono::seconds>(last_lag) == std::chrono::duration_cast<std::chrono::seconds>(lag)) return;

	last_lag = lag;
	SetDParam(0, std::chrono::duration_cast<std::chrono::seconds>(lag).count());
	ShowErrorMessage(STR_NETWORK_ERROR_CLIENT_GUI_LOST_CONNECTION_CAPTION, STR_NETWORK_ERROR_CLIENT_GUI_LOST_CONNECTION, WL_INFO);
}


/** Is called after a client is connected to the server */
void NetworkClient_Connected()
{
	/* Set the frame-counter to 0 so nothing happens till we are ready */
	_frame_counter = 0;
	_frame_counter_server = 0;
	last_ack_frame = 0;
	/* Request the game-info */
	MyClient::SendJoin();
}

/**
 * Send a remote console command.
 * @param password The password.
 * @param command The command to execute.
 */
void NetworkClientSendRcon(const std::string &password, const std::string &command)
{
	MyClient::SendRCon(password, command);
}

/**
 * Notify the server of this client wanting to be moved to another company.
 * @param company_id id of the company the client wishes to be moved to.
 * @param pass the password, is only checked on the server end if a password is needed.
 * @return void
 */
void NetworkClientRequestMove(CompanyID company_id, const std::string &pass)
{
	MyClient::SendMove(company_id, pass);
}

/**
 * Move the clients of a company to the spectators.
 * @param cid The company to move the clients of.
 */
void NetworkClientsToSpectators(CompanyID cid)
{
	Backup<CompanyID> cur_company(_current_company, FILE_LINE);
	/* If our company is changing owner, go to spectators */
	if (cid == _local_company) SetLocalCompany(COMPANY_SPECTATOR);

	for (NetworkClientInfo *ci : NetworkClientInfo::Iterate()) {
		if (ci->client_playas != cid) continue;
		NetworkTextMessage(NETWORK_ACTION_COMPANY_SPECTATOR, CC_DEFAULT, false, ci->client_name);
		ci->client_playas = COMPANY_SPECTATOR;
	}

	cur_company.Restore();
}

/**
 * Check whether the given client name is deemed valid for use in network games.
 * An empty name (null or '') is not valid as that is essentially no name at all.
 * A name starting with white space is not valid for tab completion purposes.
 * @param client_name The client name to check for validity.
 * @return True iff the name is valid.
 */
bool NetworkIsValidClientName(const std::string_view client_name)
{
	if (client_name.empty()) return false;
	if (client_name[0] == ' ') return false;
	return true;
}

/**
 * Trim the given client name in place, i.e. remove leading and trailing spaces.
 * After the trim check whether the client name is valid. A client name is valid
 * whenever the name is not empty and does not start with spaces. This check is
 * done via \c NetworkIsValidClientName.
 * When the client name is valid, this function returns true.
 * When the client name is not valid a GUI error message is shown telling the
 * user to set the client name and this function returns false.
 *
 * This function is not suitable for ensuring a valid client name at the server
 * as the error message will then be shown to the host instead of the client.
 * @param client_name The client name to validate. It will be trimmed of leading
 *                    and trailing spaces.
 * @return True iff the client name is valid.
 */
bool NetworkValidateClientName(std::string &client_name)
{
	StrTrimInPlace(client_name);
	if (NetworkIsValidClientName(client_name)) return true;

	ShowErrorMessage(STR_NETWORK_ERROR_BAD_PLAYER_NAME, INVALID_STRING_ID, WL_ERROR);
	return false;
}

/**
 * Convenience method for NetworkValidateClientName on _settings_client.network.client_name.
 * It trims the client name and checks whether it is empty. When it is empty
 * an error message is shown to the GUI user.
 * See \c NetworkValidateClientName(char*) for details about the functionality.
 * @return True iff the client name is valid.
 */
bool NetworkValidateOurClientName()
{
	return NetworkValidateClientName(_settings_client.network.client_name);
}

/**
 * Send the server our name as callback from the setting.
 * @param newname The new client name.
 */
void NetworkUpdateClientName(const std::string &client_name)
{
	NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(_network_own_client_id);
	if (ci == nullptr) return;

	/* Don't change the name if it is the same as the old name */
	if (client_name.compare(ci->client_name) != 0) {
		if (!_network_server) {
			MyClient::SendSetName(client_name);
		} else {
			/* Copy to a temporary buffer so no #n gets added after our name in the settings when there are duplicate names. */
			std::string temporary_name = client_name;
			if (NetworkMakeClientNameUnique(temporary_name)) {
				NetworkTextMessage(NETWORK_ACTION_NAME_CHANGE, CC_DEFAULT, false, ci->client_name, temporary_name);
				ci->client_name = temporary_name;
				NetworkUpdateClientInfo(CLIENT_ID_SERVER);
			}
		}
	}
}

/**
 * Send a chat message.
 * @param action The action associated with the message.
 * @param type The destination type.
 * @param dest The destination index, be it a company index or client id.
 * @param msg The actual message.
 * @param data Arbitrary extra data.
 */
void NetworkClientSendChat(NetworkAction action, DestType type, int dest, const std::string &msg, int64 data)
{
	MyClient::SendChat(action, type, dest, msg, data);
}

/**
 * Set/Reset company password on the client side.
 * @param password Password to be set.
 */
void NetworkClientSetCompanyPassword(const std::string &password)
{
	MyClient::SendSetPassword(password);
}

/**
 * Tell whether the client has team members who they can chat to.
 * @param cio client to check members of.
 * @return true if there is at least one team member.
 */
bool NetworkClientPreferTeamChat(const NetworkClientInfo *cio)
{
	/* Only companies actually playing can speak to team. Eg spectators cannot */
	if (!_settings_client.gui.prefer_teamchat || !Company::IsValidID(cio->client_playas)) return false;

	for (const NetworkClientInfo *ci : NetworkClientInfo::Iterate()) {
		if (ci->client_playas == cio->client_playas && ci != cio) return true;
	}

	return false;
}

/**
 * Check if max_companies has been reached on the server (local check only).
 * @return true if the max value has been reached or exceeded, false otherwise.
 */
bool NetworkMaxCompaniesReached()
{
	return Company::GetNumItems() >= (_network_server ? _settings_client.network.max_companies : _network_server_max_companies);
}