1 /* $Id$ */

     2 

     3 #ifdef ENABLE_NETWORK

     4 

     5 #include "../stdafx.h"

     6 #include "../debug.h"

     7 #include "../string.h"

     8 #include "network_data.h"

     9 #include "../date.h"

    10 #include "../map.h"

    11 #include "network_gamelist.h"

    12 #include "network_udp.h"

    13 #include "../variables.h"

    14 #include "../newgrf_config.h"

    15 

    16 #include "core/udp.h"

    17 

    18 /**

    19  * @file network_udp.c This file handles the UDP related communication.

    20  *

    21  * This is the GameServer <-> MasterServer and GameServer <-> GameClient

    22  * communication before the game is being joined.

    23  */

    24 

    25 enum {

    26 	ADVERTISE_NORMAL_INTERVAL = 30000, // interval between advertising in ticks (15 minutes)

    27 	ADVERTISE_RETRY_INTERVAL  =   300, // readvertise when no response after this many ticks (9 seconds)

    28 	ADVERTISE_RETRY_TIMES     =     3  // give up readvertising after this much failed retries

    29 };

    30 

    31 #define DEF_UDP_RECEIVE_COMMAND(type) void NetworkPacketReceive_ ## type ## _command(Packet *p, struct sockaddr_in *client_addr)

    32 

    33 static NetworkClientState _udp_cs;

    34 

    35 DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_FIND_SERVER)

    36 {

    37 	Packet *packet;

    38 	// Just a fail-safe.. should never happen

    39 	if (!_network_udp_server)

    40 		return;

    41 

    42 	packet = NetworkSend_Init(PACKET_UDP_SERVER_RESPONSE);

    43 

    44 	// Update some game_info

    45 	_network_game_info.game_date     = _date;

    46 	_network_game_info.map_width     = MapSizeX();

    47 	_network_game_info.map_height    = MapSizeY();

    48 	_network_game_info.map_set       = _opt.landscape;

    49 	_network_game_info.companies_on  = ActivePlayerCount();

    50 	_network_game_info.spectators_on = NetworkSpectatorCount();

    51 	_network_game_info.grfconfig     = _grfconfig;

    52 

    53 	NetworkSend_NetworkGameInfo(p, &_network_game_info);

    54 

    55 	// Let the client know that we are here

    56 	NetworkSendUDP_Packet(_udp_server_socket, packet, client_addr);

    57 

    58 	free(packet);

    59 

    60 	DEBUG(net, 2, "[udp] queried from '%s'", inet_ntoa(client_addr->sin_addr));

    61 }

    62 

    63 void HandleIncomingNetworkGameInfoGRFConfig(GRFConfig *config)

    64 {

    65 	/* Find the matching GRF file */

    66 	const GRFConfig *f = FindGRFConfig(config->grfid, config->md5sum);

    67 	if (f == NULL) {

    68 		/* Don't know the GRF, so mark game incompatible and the (possibly)

    69 		 * already resolved name for this GRF (another server has sent the

    70 		 * name of the GRF already */

    71 		config->name     = FindUnknownGRFName(config->grfid, config->md5sum, true);

    72 		SETBIT(config->flags, GCF_NOT_FOUND);

    73 	} else {

    74 		config->filename = f->filename;

    75 		config->name     = f->name;

    76 		config->info     = f->info;

    77 	}

    78 	SETBIT(config->flags, GCF_COPY);

    79 }

    80 

    81 DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_RESPONSE)

    82 {

    83 	extern const char _openttd_revision[];

    84 	NetworkGameList *item;

    85 

    86 	// Just a fail-safe.. should never happen

    87 	if (_network_udp_server || _udp_cs.has_quit) return;

    88 

    89 	DEBUG(net, 4, "[udp] server response from %s:%d", inet_ntoa(client_addr->sin_addr),ntohs(client_addr->sin_port));

    90 

    91 	// Find next item

    92 	item = NetworkGameListAddItem(inet_addr(inet_ntoa(client_addr->sin_addr)), ntohs(client_addr->sin_port));

    93 

    94 	NetworkRecv_NetworkGameInfo(&_udp_cs, p, &item->info);

    95 

    96 	item->info.compatible = true;

    97 	{

    98 		/* Checks whether there needs to be a request for names of GRFs and makes

    99 		 * the request if necessary. GRFs that need to be requested are the GRFs

   100 		 * that do not exist on the clients system and we do not have the name

   101 		 * resolved of, i.e. the name is still UNKNOWN_GRF_NAME_PLACEHOLDER.

   102 		 * The in_request array and in_request_count are used so there is no need

   103 		 * to do a second loop over the GRF list, which can be relatively expensive

   104 		 * due to the string comparisons. */

   105 		const GRFConfig *in_request[NETWORK_MAX_GRF_COUNT];

   106 		const GRFConfig *c;

   107 		uint in_request_count = 0;

   108 		struct sockaddr_in out_addr;

   109 

   110 		for (c = item->info.grfconfig; c != NULL; c = c->next) {

   111 			if (HASBIT(c->flags, GCF_NOT_FOUND)) item->info.compatible = false;

   112 			if (!HASBIT(c->flags, GCF_NOT_FOUND) || strcmp(c->name, UNKNOWN_GRF_NAME_PLACEHOLDER) != 0) continue;

   113 			in_request[in_request_count] = c;

   114 			in_request_count++;

   115 		}

   116 

   117 		if (in_request_count > 0) {

   118 			/* There are 'unknown' GRFs, now send a request for them */

   119 			uint i;

   120 			Packet *packet = NetworkSend_Init(PACKET_UDP_CLIENT_GET_NEWGRFS);

   121 

   122 			NetworkSend_uint8 (packet, in_request_count);

   123 			for (i = 0; i < in_request_count; i++) {

   124 				NetworkSend_GRFIdentifier(packet, in_request[i]);

   125 			}

   126 

   127 			out_addr.sin_family      = AF_INET;

   128 			out_addr.sin_port        = htons(item->port);

   129 			out_addr.sin_addr.s_addr = item->ip;

   130 			NetworkSendUDP_Packet(_udp_client_socket, packet, &out_addr);

   131 			free(packet);

   132 		}

   133 	}

   134 

   135 	if (item->info.server_lang >= NETWORK_NUM_LANGUAGES) item->info.server_lang = 0;

   136 	if (item->info.map_set >= NUM_LANDSCAPE ) item->info.map_set = 0;

   137 

   138 	if (item->info.hostname[0] == '\0')

   139 		snprintf(item->info.hostname, sizeof(item->info.hostname), "%s", inet_ntoa(client_addr->sin_addr));

   140 

   141 	/* Check if we are allowed on this server based on the revision-match */

   142 	item->info.version_compatible =

   143 		strcmp(item->info.server_revision, _openttd_revision) == 0 ||

   144 		strcmp(item->info.server_revision, NOREV_STRING) == 0;

   145 	item->info.compatible &= item->info.version_compatible; // Already contains match for GRFs

   146 

   147 	item->online = true;

   148 

   149 	UpdateNetworkGameWindow(false);

   150 }

   151 

   152 DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_DETAIL_INFO)

   153 {

   154 	NetworkClientState *cs;

   155 	NetworkClientInfo *ci;

   156 	Packet *packet;

   157 	Player *player;

   158 	byte current = 0;

   159 	int i;

   160 

   161 	// Just a fail-safe.. should never happen

   162 	if (!_network_udp_server) return;

   163 

   164 	packet = NetworkSend_Init(PACKET_UDP_SERVER_DETAIL_INFO);

   165 

   166 	/* Send the amount of active companies */

   167 	NetworkSend_uint8 (packet, NETWORK_COMPANY_INFO_VERSION);

   168 	NetworkSend_uint8 (packet, ActivePlayerCount());

   169 

   170 	/* Fetch the latest version of everything */

   171 	NetworkPopulateCompanyInfo();

   172 

   173 	/* Go through all the players */

   174 	FOR_ALL_PLAYERS(player) {

   175 		/* Skip non-active players */

   176 		if (!player->is_active) continue;

   177 

   178 		current++;

   179 

   180 		/* Send the information */

   181 		NetworkSend_uint8(packet, current);

   182 

   183 		NetworkSend_string(packet, _network_player_info[player->index].company_name);

   184 		NetworkSend_uint32(packet, _network_player_info[player->index].inaugurated_year);

   185 		NetworkSend_uint64(packet, _network_player_info[player->index].company_value);

   186 		NetworkSend_uint64(packet, _network_player_info[player->index].money);

   187 		NetworkSend_uint64(packet, _network_player_info[player->index].income);

   188 		NetworkSend_uint16(packet, _network_player_info[player->index].performance);

   189 

   190 		/* Send 1 if there is a passord for the company else send 0 */

   191 		if (_network_player_info[player->index].password[0] != '\0') {

   192 			NetworkSend_uint8(packet, 1);

   193 		} else {

   194 			NetworkSend_uint8(packet, 0);

   195 		}

   196 

   197 		for (i = 0; i < NETWORK_VEHICLE_TYPES; i++)

   198 			NetworkSend_uint16(packet, _network_player_info[player->index].num_vehicle[i]);

   199 

   200 		for (i = 0; i < NETWORK_STATION_TYPES; i++)

   201 			NetworkSend_uint16(packet, _network_player_info[player->index].num_station[i]);

   202 

   203 		/* Find the clients that are connected to this player */

   204 		FOR_ALL_CLIENTS(cs) {

   205 			ci = DEREF_CLIENT_INFO(cs);

   206 			if (ci->client_playas == player->index) {

   207 				/* The uint8 == 1 indicates that a client is following */

   208 				NetworkSend_uint8(packet, 1);

   209 				NetworkSend_string(packet, ci->client_name);

   210 				NetworkSend_string(packet, ci->unique_id);

   211 				NetworkSend_uint32(packet, ci->join_date);

   212 			}

   213 		}

   214 		/* Also check for the server itself */

   215 		ci = NetworkFindClientInfoFromIndex(NETWORK_SERVER_INDEX);

   216 		if (ci->client_playas == player->index) {

   217 			/* The uint8 == 1 indicates that a client is following */

   218 			NetworkSend_uint8(packet, 1);

   219 			NetworkSend_string(packet, ci->client_name);

   220 			NetworkSend_string(packet, ci->unique_id);

   221 			NetworkSend_uint32(packet, ci->join_date);

   222 		}

   223 

   224 		/* Indicates end of client list */

   225 		NetworkSend_uint8(packet, 0);

   226 	}

   227 

   228 	/* And check if we have any spectators */

   229 	FOR_ALL_CLIENTS(cs) {

   230 		ci = DEREF_CLIENT_INFO(cs);

   231 		if (!IsValidPlayer(ci->client_playas)) {

   232 			/* The uint8 == 1 indicates that a client is following */

   233 			NetworkSend_uint8(packet, 1);

   234 			NetworkSend_string(packet, ci->client_name);

   235 			NetworkSend_string(packet, ci->unique_id);

   236 			NetworkSend_uint32(packet, ci->join_date);

   237 		}

   238 	}

   239 

   240 	/* Also check for the server itself */

   241 	ci = NetworkFindClientInfoFromIndex(NETWORK_SERVER_INDEX);

   242 	if (!IsValidPlayer(ci->client_playas)) {

   243 		/* The uint8 == 1 indicates that a client is following */

   244 		NetworkSend_uint8(packet, 1);

   245 		NetworkSend_string(packet, ci->client_name);

   246 		NetworkSend_string(packet, ci->unique_id);

   247 		NetworkSend_uint32(packet, ci->join_date);

   248 	}

   249 

   250 	/* Indicates end of client list */

   251 	NetworkSend_uint8(packet, 0);

   252 

   253 	NetworkSendUDP_Packet(_udp_server_socket, packet, client_addr);

   254 

   255 	free(packet);

   256 }

   257 

   258 DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_MASTER_RESPONSE_LIST)

   259 {

   260 	int i;

   261 	struct in_addr ip;

   262 	uint16 port;

   263 	uint8 ver;

   264 

   265 	/* packet begins with the protocol version (uint8)

   266 	 * then an uint16 which indicates how many

   267 	 * ip:port pairs are in this packet, after that

   268 	 * an uint32 (ip) and an uint16 (port) for each pair

   269 	 */

   270 

   271 	ver = NetworkRecv_uint8(&_udp_cs, p);

   272 

   273 	if (_udp_cs.has_quit) return;

   274 

   275 	if (ver == 1) {

   276 		for (i = NetworkRecv_uint16(&_udp_cs, p); i != 0 ; i--) {

   277 			ip.s_addr = TO_LE32(NetworkRecv_uint32(&_udp_cs, p));

   278 			port = NetworkRecv_uint16(&_udp_cs, p);

   279 			NetworkUDPQueryServer(inet_ntoa(ip), port);

   280 		}

   281 	}

   282 }

   283 

   284 DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_MASTER_ACK_REGISTER)

   285 {

   286 	_network_advertise_retries = 0;

   287 	DEBUG(net, 2, "[udp] advertising on master server successfull");

   288 

   289 	/* We are advertised, but we don't want to! */

   290 	if (!_network_advertise) NetworkUDPRemoveAdvertise();

   291 }

   292 

   293 /**

   294  * A client has requested the names of some NewGRFs.

   295  *

   296  * Replying this can be tricky as we have a limit of SEND_MTU bytes

   297  * in the reply packet and we can send up to 100 bytes per NewGRF

   298  * (GRF ID, MD5sum and NETWORK_GRF_NAME_LENGTH bytes for the name).

   299  * As SEND_MTU is _much_ less than 100 * NETWORK_MAX_GRF_COUNT, it

   300  * could be that a packet overflows. To stop this we only reply

   301  * with the first N NewGRFs so that if the first N + 1 NewGRFs

   302  * would be sent, the packet overflows.

   303  * in_reply and in_reply_count are used to keep a list of GRFs to

   304  * send in the reply.

   305  */

   306 DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_GET_NEWGRFS)

   307 {

   308 	uint8 num_grfs;

   309 	uint i;

   310 

   311 	const GRFConfig *in_reply[NETWORK_MAX_GRF_COUNT];

   312 	Packet *packet;

   313 	uint8 in_reply_count = 0;

   314 	uint packet_len = 0;

   315 

   316 	/* Just a fail-safe.. should never happen */

   317 	if (_udp_cs.has_quit) return;

   318 

   319 	DEBUG(net, 6, "[udp] newgrf data request from %s:%d", inet_ntoa(client_addr->sin_addr), ntohs(client_addr->sin_port));

   320 

   321 	num_grfs = NetworkRecv_uint8 (&_udp_cs, p);

   322 	if (num_grfs > NETWORK_MAX_GRF_COUNT) return;

   323 

   324 	for (i = 0; i < num_grfs; i++) {

   325 		GRFConfig c;

   326 		const GRFConfig *f;

   327 

   328 		NetworkRecv_GRFIdentifier(&_udp_cs, p, &c);

   329 

   330 		/* Find the matching GRF file */

   331 		f = FindGRFConfig(c.grfid, c.md5sum);

   332 		if (f == NULL) continue; // The GRF is unknown to this server

   333 

   334 		/* If the reply might exceed the size of the packet, only reply

   335 		 * the current list and do not send the other data.

   336 		 * The name could be an empty string, if so take the filename. */

   337 		packet_len += sizeof(c.grfid) + sizeof(c.md5sum) +

   338 				min(strlen((f->name != NULL && strlen(f->name) > 0) ? f->name : f->filename) + 1, NETWORK_GRF_NAME_LENGTH);

   339 		if (packet_len > SEND_MTU - 4) { // 4 is 3 byte header + grf count in reply

   340 			break;

   341 		}

   342 		in_reply[in_reply_count] = f;

   343 		in_reply_count++;

   344 	}

   345 

   346 	if (in_reply_count == 0) return;

   347 

   348 	packet = NetworkSend_Init(PACKET_UDP_SERVER_NEWGRFS);

   349 	NetworkSend_uint8 (packet, in_reply_count);

   350 	for (i = 0; i < in_reply_count; i++) {

   351 		char name[NETWORK_GRF_NAME_LENGTH];

   352 

   353 		/* The name could be an empty string, if so take the filename */

   354 		ttd_strlcpy(name, (in_reply[i]->name != NULL && strlen(in_reply[i]->name) > 0) ?

   355 				in_reply[i]->name : in_reply[i]->filename, sizeof(name));

   356 	 	NetworkSend_GRFIdentifier(packet, in_reply[i]);

   357 		NetworkSend_string(packet, name);

   358 	}

   359 

   360 	NetworkSendUDP_Packet(_udp_server_socket, packet, client_addr);

   361 	free(packet);

   362 }

   363 

   364 /** The return of the client's request of the names of some NewGRFs */

   365 DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_NEWGRFS)

   366 {

   367 	uint8 num_grfs;

   368 	uint i;

   369 

   370 	/* Just a fail-safe.. should never happen */

   371 	if (_udp_cs.has_quit) return;

   372 

   373 	DEBUG(net, 6, "[udp] newgrf data reply from %s:%d", inet_ntoa(client_addr->sin_addr),ntohs(client_addr->sin_port));

   374 

   375 	num_grfs = NetworkRecv_uint8 (&_udp_cs, p);

   376 	if (num_grfs > NETWORK_MAX_GRF_COUNT) return;

   377 

   378 	for (i = 0; i < num_grfs; i++) {

   379 		char *unknown_name;

   380 		char name[NETWORK_GRF_NAME_LENGTH];

   381 		GRFConfig c;

   382 

   383 		NetworkRecv_GRFIdentifier(&_udp_cs, p, &c);

   384 		NetworkRecv_string(&_udp_cs, p, name, sizeof(name));

   385 

   386 		/* An empty name is not possible under normal circumstances

   387 		 * and causes problems when showing the NewGRF list. */

   388 		if (strlen(name) == 0) continue;

   389 

   390 		/* Finds the fake GRFConfig for the just read GRF ID and MD5sum tuple.

   391 		 * If it exists and not resolved yet, then name of the fake GRF is

   392 		 * overwritten with the name from the reply. */

   393 		unknown_name = FindUnknownGRFName(c.grfid, c.md5sum, false);

   394 		if (unknown_name != NULL && strcmp(unknown_name, UNKNOWN_GRF_NAME_PLACEHOLDER) == 0) {

   395 			ttd_strlcpy(unknown_name, name, NETWORK_GRF_NAME_LENGTH);

   396 		}

   397 	}

   398 }

   399 

   400 

   401 // The layout for the receive-functions by UDP

   402 typedef void NetworkUDPPacket(Packet *p, struct sockaddr_in *client_addr);

   403 

   404 static NetworkUDPPacket* const _network_udp_packet[] = {

   405 	RECEIVE_COMMAND(PACKET_UDP_CLIENT_FIND_SERVER),

   406 	RECEIVE_COMMAND(PACKET_UDP_SERVER_RESPONSE),

   407 	RECEIVE_COMMAND(PACKET_UDP_CLIENT_DETAIL_INFO),

   408 	NULL,

   409 	NULL,

   410 	RECEIVE_COMMAND(PACKET_UDP_MASTER_ACK_REGISTER),

   411 	NULL,

   412 	RECEIVE_COMMAND(PACKET_UDP_MASTER_RESPONSE_LIST),

   413 	NULL,

   414 	RECEIVE_COMMAND(PACKET_UDP_CLIENT_GET_NEWGRFS),

   415 	RECEIVE_COMMAND(PACKET_UDP_SERVER_NEWGRFS),

   416 };

   417 

   418 

   419 // If this fails, check the array above with network_data.h

   420 assert_compile(lengthof(_network_udp_packet) == PACKET_UDP_END);

   421 

   422 

   423 void NetworkHandleUDPPacket(Packet *p, struct sockaddr_in *client_addr)

   424 {

   425 	byte type;

   426 

   427 	/* Fake a client, so we can see when there is an illegal packet */

   428 	_udp_cs.socket = INVALID_SOCKET;

   429 	_udp_cs.has_quit = false;

   430 

   431 	type = NetworkRecv_uint8(&_udp_cs, p);

   432 

   433 	if (type < PACKET_UDP_END && _network_udp_packet[type] != NULL && !_udp_cs.has_quit) {

   434 		_network_udp_packet[type](p, client_addr);

   435 	} else {

   436 		if (!_udp_cs.has_quit) {

   437 			DEBUG(net, 0, "[udp] received invalid packet type %d", type);

   438 		} else {

   439 			DEBUG(net, 0, "[udp] received illegal packet");

   440 		}

   441 	}

   442 }

   443 

   444 

   445 // Close UDP connection

   446 void NetworkUDPClose(void)

   447 {

   448 	DEBUG(net, 1, "[udp] closed listeners");

   449 

   450 	if (_network_udp_server) {

   451 		if (_udp_server_socket != INVALID_SOCKET) {

   452 			closesocket(_udp_server_socket);

   453 			_udp_server_socket = INVALID_SOCKET;

   454 		}

   455 

   456 		if (_udp_master_socket != INVALID_SOCKET) {

   457 			closesocket(_udp_master_socket);

   458 			_udp_master_socket = INVALID_SOCKET;

   459 		}

   460 

   461 		_network_udp_server = false;

   462 		_network_udp_broadcast = 0;

   463 	} else {

   464 		if (_udp_client_socket != INVALID_SOCKET) {

   465 			closesocket(_udp_client_socket);

   466 			_udp_client_socket = INVALID_SOCKET;

   467 		}

   468 		_network_udp_broadcast = 0;

   469 	}

   470 }

   471 

   472 // Broadcast to all ips

   473 static void NetworkUDPBroadCast(SOCKET udp)

   474 {

   475 	Packet* p = NetworkSend_Init(PACKET_UDP_CLIENT_FIND_SERVER);

   476 	uint i;

   477 

   478 	for (i = 0; _broadcast_list[i] != 0; i++) {

   479 		struct sockaddr_in out_addr;

   480 

   481 		out_addr.sin_family = AF_INET;

   482 		out_addr.sin_port = htons(_network_server_port);

   483 		out_addr.sin_addr.s_addr = _broadcast_list[i];

   484 

   485 		DEBUG(net, 4, "[udp] broadcasting to %s", inet_ntoa(out_addr.sin_addr));

   486 

   487 		NetworkSendUDP_Packet(udp, p, &out_addr);

   488 	}

   489 

   490 	free(p);

   491 }

   492 

   493 

   494 // Request the the server-list from the master server

   495 void NetworkUDPQueryMasterServer(void)

   496 {

   497 	struct sockaddr_in out_addr;

   498 	Packet *p;

   499 

   500 	if (_udp_client_socket == INVALID_SOCKET)

   501 		if (!NetworkUDPListen(&_udp_client_socket, 0, 0, true))

   502 			return;

   503 

   504 	p = NetworkSend_Init(PACKET_UDP_CLIENT_GET_LIST);

   505 

   506 	out_addr.sin_family = AF_INET;

   507 	out_addr.sin_port = htons(NETWORK_MASTER_SERVER_PORT);

   508 	out_addr.sin_addr.s_addr = NetworkResolveHost(NETWORK_MASTER_SERVER_HOST);

   509 

   510 	// packet only contains protocol version

   511 	NetworkSend_uint8(p, NETWORK_MASTER_SERVER_VERSION);

   512 

   513 	NetworkSendUDP_Packet(_udp_client_socket, p, &out_addr);

   514 

   515 	DEBUG(net, 2, "[udp] master server queried at %s:%d", inet_ntoa(out_addr.sin_addr),ntohs(out_addr.sin_port));

   516 

   517 	free(p);

   518 }

   519 

   520 // Find all servers

   521 void NetworkUDPSearchGame(void)

   522 {

   523 	// We are still searching..

   524 	if (_network_udp_broadcast > 0) return;

   525 

   526 	// No UDP-socket yet..

   527 	if (_udp_client_socket == INVALID_SOCKET)

   528 		if (!NetworkUDPListen(&_udp_client_socket, 0, 0, true))

   529 			return;

   530 

   531 	DEBUG(net, 0, "[udp] searching server");

   532 

   533 	NetworkUDPBroadCast(_udp_client_socket);

   534 	_network_udp_broadcast = 300; // Stay searching for 300 ticks

   535 }

   536 

   537 NetworkGameList *NetworkUDPQueryServer(const char* host, unsigned short port)

   538 {

   539 	struct sockaddr_in out_addr;

   540 	Packet *p;

   541 	NetworkGameList *item;

   542 

   543 	// No UDP-socket yet..

   544 	if (_udp_client_socket == INVALID_SOCKET)

   545 		if (!NetworkUDPListen(&_udp_client_socket, 0, 0, true))

   546 			return NULL;

   547 

   548 	out_addr.sin_family = AF_INET;

   549 	out_addr.sin_port = htons(port);

   550 	out_addr.sin_addr.s_addr = NetworkResolveHost(host);

   551 

   552 	// Clear item in gamelist

   553 	item = NetworkGameListAddItem(inet_addr(inet_ntoa(out_addr.sin_addr)), ntohs(out_addr.sin_port));

   554 	memset(&item->info, 0, sizeof(item->info));

   555 	ttd_strlcpy(item->info.server_name, host, lengthof(item->info.server_name));

   556 	ttd_strlcpy(item->info.hostname, host, lengthof(item->info.hostname));

   557 	item->online = false;

   558 

   559 	// Init the packet

   560 	p = NetworkSend_Init(PACKET_UDP_CLIENT_FIND_SERVER);

   561 

   562 	NetworkSendUDP_Packet(_udp_client_socket, p, &out_addr);

   563 

   564 	free(p);

   565 

   566 	UpdateNetworkGameWindow(false);

   567 	return item;

   568 }

   569 

   570 /* Remove our advertise from the master-server */

   571 void NetworkUDPRemoveAdvertise(void)

   572 {

   573 	struct sockaddr_in out_addr;

   574 	Packet *p;

   575 

   576 	/* Check if we are advertising */

   577 	if (!_networking || !_network_server || !_network_udp_server) return;

   578 

   579 	/* check for socket */

   580 	if (_udp_master_socket == INVALID_SOCKET)

   581 		if (!NetworkUDPListen(&_udp_master_socket, _network_server_bind_ip, 0, false))

   582 			return;

   583 

   584 	DEBUG(net, 1, "[udp] removing advertise from master server");

   585 

   586 	/* Find somewhere to send */

   587 	out_addr.sin_family = AF_INET;

   588 	out_addr.sin_port = htons(NETWORK_MASTER_SERVER_PORT);

   589 	out_addr.sin_addr.s_addr = NetworkResolveHost(NETWORK_MASTER_SERVER_HOST);

   590 

   591 	/* Send the packet */

   592 	p = NetworkSend_Init(PACKET_UDP_SERVER_UNREGISTER);

   593 	/* Packet is: Version, server_port */

   594 	NetworkSend_uint8(p, NETWORK_MASTER_SERVER_VERSION);

   595 	NetworkSend_uint16(p, _network_server_port);

   596 	NetworkSendUDP_Packet(_udp_master_socket, p, &out_addr);

   597 

   598 	free(p);

   599 }

   600 

   601 /* Register us to the master server

   602      This function checks if it needs to send an advertise */

   603 void NetworkUDPAdvertise(void)

   604 {

   605 	struct sockaddr_in out_addr;

   606 	Packet *p;

   607 

   608 	/* Check if we should send an advertise */

   609 	if (!_networking || !_network_server || !_network_udp_server || !_network_advertise)

   610 		return;

   611 

   612 	/* check for socket */

   613 	if (_udp_master_socket == INVALID_SOCKET)

   614 		if (!NetworkUDPListen(&_udp_master_socket, _network_server_bind_ip, 0, false))

   615 			return;

   616 

   617 	if (_network_need_advertise) {

   618 		_network_need_advertise = false;

   619 		_network_advertise_retries = ADVERTISE_RETRY_TIMES;

   620 	} else {

   621 		/* Only send once every ADVERTISE_NORMAL_INTERVAL ticks */

   622 		if (_network_advertise_retries == 0) {

   623 			if ((_network_last_advertise_frame + ADVERTISE_NORMAL_INTERVAL) > _frame_counter)

   624 				return;

   625 			_network_advertise_retries = ADVERTISE_RETRY_TIMES;

   626 		}

   627 

   628 		if ((_network_last_advertise_frame + ADVERTISE_RETRY_INTERVAL) > _frame_counter)

   629 			return;

   630 	}

   631 

   632 	_network_advertise_retries--;

   633 	_network_last_advertise_frame = _frame_counter;

   634 

   635 	/* Find somewhere to send */

   636 	out_addr.sin_family = AF_INET;

   637 	out_addr.sin_port = htons(NETWORK_MASTER_SERVER_PORT);

   638 	out_addr.sin_addr.s_addr = NetworkResolveHost(NETWORK_MASTER_SERVER_HOST);

   639 

   640 	DEBUG(net, 1, "[udp] advertising to master server");

   641 

   642 	/* Send the packet */

   643 	p = NetworkSend_Init(PACKET_UDP_SERVER_REGISTER);

   644 	/* Packet is: WELCOME_MESSAGE, Version, server_port */

   645 	NetworkSend_string(p, NETWORK_MASTER_SERVER_WELCOME_MESSAGE);

   646 	NetworkSend_uint8(p, NETWORK_MASTER_SERVER_VERSION);

   647 	NetworkSend_uint16(p, _network_server_port);

   648 	NetworkSendUDP_Packet(_udp_master_socket, p, &out_addr);

   649 

   650 	free(p);

   651 }

   652 

   653 void NetworkUDPInitialize(void)

   654 {

   655 	_udp_client_socket = INVALID_SOCKET;

   656 	_udp_server_socket = INVALID_SOCKET;

   657 	_udp_master_socket = INVALID_SOCKET;

   658 

   659 	_network_udp_server = false;

   660 	_network_udp_broadcast = 0;

   661 }

   662 

   663 #endif /* ENABLE_NETWORK */