(svn r7751) -Codechange: move network_* to a new network map. Furthermore move the low level network functions to network/core, so they can be reused by the masterserver and website-serverlist-updater.

1 files changed, 663 insertions, 0 deletions

diff --git a/network/network_udp.c b/network/network_udp.c
new file mode 100644
index 000000000..aeef75e77
--- /dev/null
+++ b/network/network_udp.c
@@ -0,0 +1,663 @@
+/* $Id$ */
+
+#ifdef ENABLE_NETWORK
+
+#include "../stdafx.h"
+#include "../debug.h"
+#include "../string.h"
+#include "network_data.h"
+#include "../date.h"
+#include "../map.h"
+#include "network_gamelist.h"
+#include "network_udp.h"
+#include "../variables.h"
+#include "../newgrf_config.h"
+
+#include "core/udp.h"
+
+/**
+ * @file network_udp.c This file handles the UDP related communication.
+ *
+ * This is the GameServer <-> MasterServer and GameServer <-> GameClient
+ * communication before the game is being joined.
+ */
+
+enum {
+	ADVERTISE_NORMAL_INTERVAL = 30000, // interval between advertising in ticks (15 minutes)
+	ADVERTISE_RETRY_INTERVAL  =   300, // readvertise when no response after this many ticks (9 seconds)
+	ADVERTISE_RETRY_TIMES     =     3  // give up readvertising after this much failed retries
+};
+
+#define DEF_UDP_RECEIVE_COMMAND(type) void NetworkPacketReceive_ ## type ## _command(Packet *p, struct sockaddr_in *client_addr)
+
+static NetworkClientState _udp_cs;
+
+DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_FIND_SERVER)
+{
+	Packet *packet;
+	// Just a fail-safe.. should never happen
+	if (!_network_udp_server)
+		return;
+
+	packet = NetworkSend_Init(PACKET_UDP_SERVER_RESPONSE);
+
+	// Update some game_info
+	_network_game_info.game_date     = _date;
+	_network_game_info.map_width     = MapSizeX();
+	_network_game_info.map_height    = MapSizeY();
+	_network_game_info.map_set       = _opt.landscape;
+	_network_game_info.companies_on  = ActivePlayerCount();
+	_network_game_info.spectators_on = NetworkSpectatorCount();
+	_network_game_info.grfconfig     = _grfconfig;
+
+	NetworkSend_NetworkGameInfo(p, &_network_game_info);
+
+	// Let the client know that we are here
+	NetworkSendUDP_Packet(_udp_server_socket, packet, client_addr);
+
+	free(packet);
+
+	DEBUG(net, 2, "[udp] queried from '%s'", inet_ntoa(client_addr->sin_addr));
+}
+
+void HandleIncomingNetworkGameInfoGRFConfig(GRFConfig *config)
+{
+	/* Find the matching GRF file */
+	const GRFConfig *f = FindGRFConfig(config->grfid, config->md5sum);
+	if (f == NULL) {
+		/* Don't know the GRF, so mark game incompatible and the (possibly)
+		 * already resolved name for this GRF (another server has sent the
+		 * name of the GRF already */
+		config->name     = FindUnknownGRFName(config->grfid, config->md5sum, true);
+		SETBIT(config->flags, GCF_NOT_FOUND);
+	} else {
+		config->filename = f->filename;
+		config->name     = f->name;
+		config->info     = f->info;
+	}
+	SETBIT(config->flags, GCF_COPY);
+}
+
+DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_RESPONSE)
+{
+	extern const char _openttd_revision[];
+	NetworkGameList *item;
+
+	// Just a fail-safe.. should never happen
+	if (_network_udp_server || _udp_cs.has_quit) return;
+
+	DEBUG(net, 4, "[udp] server response from %s:%d", inet_ntoa(client_addr->sin_addr),ntohs(client_addr->sin_port));
+
+	// Find next item
+	item = NetworkGameListAddItem(inet_addr(inet_ntoa(client_addr->sin_addr)), ntohs(client_addr->sin_port));
+
+	NetworkRecv_NetworkGameInfo(&_udp_cs, p, &item->info);
+
+	item->info.compatible = true;
+	{
+		/* Checks whether there needs to be a request for names of GRFs and makes
+		 * the request if necessary. GRFs that need to be requested are the GRFs
+		 * that do not exist on the clients system and we do not have the name
+		 * resolved of, i.e. the name is still UNKNOWN_GRF_NAME_PLACEHOLDER.
+		 * The in_request array and in_request_count are used so there is no need
+		 * to do a second loop over the GRF list, which can be relatively expensive
+		 * due to the string comparisons. */
+		const GRFConfig *in_request[NETWORK_MAX_GRF_COUNT];
+		const GRFConfig *c;
+		uint in_request_count = 0;
+		struct sockaddr_in out_addr;
+
+		for (c = item->info.grfconfig; c != NULL; c = c->next) {
+			if (HASBIT(c->flags, GCF_NOT_FOUND)) item->info.compatible = false;
+			if (!HASBIT(c->flags, GCF_NOT_FOUND) || strcmp(c->name, UNKNOWN_GRF_NAME_PLACEHOLDER) != 0) continue;
+			in_request[in_request_count] = c;
+			in_request_count++;
+		}
+
+		if (in_request_count > 0) {
+			/* There are 'unknown' GRFs, now send a request for them */
+			uint i;
+			Packet *packet = NetworkSend_Init(PACKET_UDP_CLIENT_GET_NEWGRFS);
+
+			NetworkSend_uint8 (packet, in_request_count);
+			for (i = 0; i < in_request_count; i++) {
+				NetworkSend_GRFIdentifier(packet, in_request[i]);
+			}
+
+			out_addr.sin_family      = AF_INET;
+			out_addr.sin_port        = htons(item->port);
+			out_addr.sin_addr.s_addr = item->ip;
+			NetworkSendUDP_Packet(_udp_client_socket, packet, &out_addr);
+			free(packet);
+		}
+	}
+
+	if (item->info.server_lang >= NETWORK_NUM_LANGUAGES) item->info.server_lang = 0;
+	if (item->info.map_set >= NUM_LANDSCAPE ) item->info.map_set = 0;
+
+	if (item->info.hostname[0] == '\0')
+		snprintf(item->info.hostname, sizeof(item->info.hostname), "%s", inet_ntoa(client_addr->sin_addr));
+
+	/* Check if we are allowed on this server based on the revision-match */
+	item->info.version_compatible =
+		strcmp(item->info.server_revision, _openttd_revision) == 0 ||
+		strcmp(item->info.server_revision, NOREV_STRING) == 0;
+	item->info.compatible &= item->info.version_compatible; // Already contains match for GRFs
+
+	item->online = true;
+
+	UpdateNetworkGameWindow(false);
+}
+
+DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_DETAIL_INFO)
+{
+	NetworkClientState *cs;
+	NetworkClientInfo *ci;
+	Packet *packet;
+	Player *player;
+	byte current = 0;
+	int i;
+
+	// Just a fail-safe.. should never happen
+	if (!_network_udp_server) return;
+
+	packet = NetworkSend_Init(PACKET_UDP_SERVER_DETAIL_INFO);
+
+	/* Send the amount of active companies */
+	NetworkSend_uint8 (packet, NETWORK_COMPANY_INFO_VERSION);
+	NetworkSend_uint8 (packet, ActivePlayerCount());
+
+	/* Fetch the latest version of everything */
+	NetworkPopulateCompanyInfo();
+
+	/* Go through all the players */
+	FOR_ALL_PLAYERS(player) {
+		/* Skip non-active players */
+		if (!player->is_active) continue;
+
+		current++;
+
+		/* Send the information */
+		NetworkSend_uint8(packet, current);
+
+		NetworkSend_string(packet, _network_player_info[player->index].company_name);
+		NetworkSend_uint32(packet, _network_player_info[player->index].inaugurated_year);
+		NetworkSend_uint64(packet, _network_player_info[player->index].company_value);
+		NetworkSend_uint64(packet, _network_player_info[player->index].money);
+		NetworkSend_uint64(packet, _network_player_info[player->index].income);
+		NetworkSend_uint16(packet, _network_player_info[player->index].performance);
+
+		/* Send 1 if there is a passord for the company else send 0 */
+		if (_network_player_info[player->index].password[0] != '\0') {
+			NetworkSend_uint8(packet, 1);
+		} else {
+			NetworkSend_uint8(packet, 0);
+		}
+
+		for (i = 0; i < NETWORK_VEHICLE_TYPES; i++)
+			NetworkSend_uint16(packet, _network_player_info[player->index].num_vehicle[i]);
+
+		for (i = 0; i < NETWORK_STATION_TYPES; i++)
+			NetworkSend_uint16(packet, _network_player_info[player->index].num_station[i]);
+
+		/* Find the clients that are connected to this player */
+		FOR_ALL_CLIENTS(cs) {
+			ci = DEREF_CLIENT_INFO(cs);
+			if (ci->client_playas == player->index) {
+				/* The uint8 == 1 indicates that a client is following */
+				NetworkSend_uint8(packet, 1);
+				NetworkSend_string(packet, ci->client_name);
+				NetworkSend_string(packet, ci->unique_id);
+				NetworkSend_uint32(packet, ci->join_date);
+			}
+		}
+		/* Also check for the server itself */
+		ci = NetworkFindClientInfoFromIndex(NETWORK_SERVER_INDEX);
+		if (ci->client_playas == player->index) {
+			/* The uint8 == 1 indicates that a client is following */
+			NetworkSend_uint8(packet, 1);
+			NetworkSend_string(packet, ci->client_name);
+			NetworkSend_string(packet, ci->unique_id);
+			NetworkSend_uint32(packet, ci->join_date);
+		}
+
+		/* Indicates end of client list */
+		NetworkSend_uint8(packet, 0);
+	}
+
+	/* And check if we have any spectators */
+	FOR_ALL_CLIENTS(cs) {
+		ci = DEREF_CLIENT_INFO(cs);
+		if (!IsValidPlayer(ci->client_playas)) {
+			/* The uint8 == 1 indicates that a client is following */
+			NetworkSend_uint8(packet, 1);
+			NetworkSend_string(packet, ci->client_name);
+			NetworkSend_string(packet, ci->unique_id);
+			NetworkSend_uint32(packet, ci->join_date);
+		}
+	}
+
+	/* Also check for the server itself */
+	ci = NetworkFindClientInfoFromIndex(NETWORK_SERVER_INDEX);
+	if (!IsValidPlayer(ci->client_playas)) {
+		/* The uint8 == 1 indicates that a client is following */
+		NetworkSend_uint8(packet, 1);
+		NetworkSend_string(packet, ci->client_name);
+		NetworkSend_string(packet, ci->unique_id);
+		NetworkSend_uint32(packet, ci->join_date);
+	}
+
+	/* Indicates end of client list */
+	NetworkSend_uint8(packet, 0);
+
+	NetworkSendUDP_Packet(_udp_server_socket, packet, client_addr);
+
+	free(packet);
+}
+
+DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_MASTER_RESPONSE_LIST)
+{
+	int i;
+	struct in_addr ip;
+	uint16 port;
+	uint8 ver;
+
+	/* packet begins with the protocol version (uint8)
+	 * then an uint16 which indicates how many
+	 * ip:port pairs are in this packet, after that
+	 * an uint32 (ip) and an uint16 (port) for each pair
+	 */
+
+	ver = NetworkRecv_uint8(&_udp_cs, p);
+
+	if (_udp_cs.has_quit) return;
+
+	if (ver == 1) {
+		for (i = NetworkRecv_uint16(&_udp_cs, p); i != 0 ; i--) {
+			ip.s_addr = TO_LE32(NetworkRecv_uint32(&_udp_cs, p));
+			port = NetworkRecv_uint16(&_udp_cs, p);
+			NetworkUDPQueryServer(inet_ntoa(ip), port);
+		}
+	}
+}
+
+DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_MASTER_ACK_REGISTER)
+{
+	_network_advertise_retries = 0;
+	DEBUG(net, 2, "[udp] advertising on master server successfull");
+
+	/* We are advertised, but we don't want to! */
+	if (!_network_advertise) NetworkUDPRemoveAdvertise();
+}
+
+/**
+ * A client has requested the names of some NewGRFs.
+ *
+ * Replying this can be tricky as we have a limit of SEND_MTU bytes
+ * in the reply packet and we can send up to 100 bytes per NewGRF
+ * (GRF ID, MD5sum and NETWORK_GRF_NAME_LENGTH bytes for the name).
+ * As SEND_MTU is _much_ less than 100 * NETWORK_MAX_GRF_COUNT, it
+ * could be that a packet overflows. To stop this we only reply
+ * with the first N NewGRFs so that if the first N + 1 NewGRFs
+ * would be sent, the packet overflows.
+ * in_reply and in_reply_count are used to keep a list of GRFs to
+ * send in the reply.
+ */
+DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_GET_NEWGRFS)
+{
+	uint8 num_grfs;
+	uint i;
+
+	const GRFConfig *in_reply[NETWORK_MAX_GRF_COUNT];
+	Packet *packet;
+	uint8 in_reply_count = 0;
+	uint packet_len = 0;
+
+	/* Just a fail-safe.. should never happen */
+	if (_udp_cs.has_quit) return;
+
+	DEBUG(net, 6, "[udp] newgrf data request from %s:%d", inet_ntoa(client_addr->sin_addr), ntohs(client_addr->sin_port));
+
+	num_grfs = NetworkRecv_uint8 (&_udp_cs, p);
+	if (num_grfs > NETWORK_MAX_GRF_COUNT) return;
+
+	for (i = 0; i < num_grfs; i++) {
+		GRFConfig c;
+		const GRFConfig *f;
+
+		NetworkRecv_GRFIdentifier(&_udp_cs, p, &c);
+
+		/* Find the matching GRF file */
+		f = FindGRFConfig(c.grfid, c.md5sum);
+		if (f == NULL) continue; // The GRF is unknown to this server
+
+		/* If the reply might exceed the size of the packet, only reply
+		 * the current list and do not send the other data.
+		 * The name could be an empty string, if so take the filename. */
+		packet_len += sizeof(c.grfid) + sizeof(c.md5sum) +
+				min(strlen((f->name != NULL && strlen(f->name) > 0) ? f->name : f->filename) + 1, NETWORK_GRF_NAME_LENGTH);
+		if (packet_len > SEND_MTU - 4) { // 4 is 3 byte header + grf count in reply
+			break;
+		}
+		in_reply[in_reply_count] = f;
+		in_reply_count++;
+	}
+
+	if (in_reply_count == 0) return;
+
+	packet = NetworkSend_Init(PACKET_UDP_SERVER_NEWGRFS);
+	NetworkSend_uint8 (packet, in_reply_count);
+	for (i = 0; i < in_reply_count; i++) {
+		char name[NETWORK_GRF_NAME_LENGTH];
+
+		/* The name could be an empty string, if so take the filename */
+		ttd_strlcpy(name, (in_reply[i]->name != NULL && strlen(in_reply[i]->name) > 0) ?
+				in_reply[i]->name : in_reply[i]->filename, sizeof(name));
+	 	NetworkSend_GRFIdentifier(packet, in_reply[i]);
+		NetworkSend_string(packet, name);
+	}
+
+	NetworkSendUDP_Packet(_udp_server_socket, packet, client_addr);
+	free(packet);
+}
+
+/** The return of the client's request of the names of some NewGRFs */
+DEF_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_NEWGRFS)
+{
+	uint8 num_grfs;
+	uint i;
+
+	/* Just a fail-safe.. should never happen */
+	if (_udp_cs.has_quit) return;
+
+	DEBUG(net, 6, "[udp] newgrf data reply from %s:%d", inet_ntoa(client_addr->sin_addr),ntohs(client_addr->sin_port));
+
+	num_grfs = NetworkRecv_uint8 (&_udp_cs, p);
+	if (num_grfs > NETWORK_MAX_GRF_COUNT) return;
+
+	for (i = 0; i < num_grfs; i++) {
+		char *unknown_name;
+		char name[NETWORK_GRF_NAME_LENGTH];
+		GRFConfig c;
+
+		NetworkRecv_GRFIdentifier(&_udp_cs, p, &c);
+		NetworkRecv_string(&_udp_cs, p, name, sizeof(name));
+
+		/* An empty name is not possible under normal circumstances
+		 * and causes problems when showing the NewGRF list. */
+		if (strlen(name) == 0) continue;
+
+		/* Finds the fake GRFConfig for the just read GRF ID and MD5sum tuple.
+		 * If it exists and not resolved yet, then name of the fake GRF is
+		 * overwritten with the name from the reply. */
+		unknown_name = FindUnknownGRFName(c.grfid, c.md5sum, false);
+		if (unknown_name != NULL && strcmp(unknown_name, UNKNOWN_GRF_NAME_PLACEHOLDER) == 0) {
+			ttd_strlcpy(unknown_name, name, NETWORK_GRF_NAME_LENGTH);
+		}
+	}
+}
+
+
+// The layout for the receive-functions by UDP
+typedef void NetworkUDPPacket(Packet *p, struct sockaddr_in *client_addr);
+
+static NetworkUDPPacket* const _network_udp_packet[] = {
+	RECEIVE_COMMAND(PACKET_UDP_CLIENT_FIND_SERVER),
+	RECEIVE_COMMAND(PACKET_UDP_SERVER_RESPONSE),
+	RECEIVE_COMMAND(PACKET_UDP_CLIENT_DETAIL_INFO),
+	NULL,
+	NULL,
+	RECEIVE_COMMAND(PACKET_UDP_MASTER_ACK_REGISTER),
+	NULL,
+	RECEIVE_COMMAND(PACKET_UDP_MASTER_RESPONSE_LIST),
+	NULL,
+	RECEIVE_COMMAND(PACKET_UDP_CLIENT_GET_NEWGRFS),
+	RECEIVE_COMMAND(PACKET_UDP_SERVER_NEWGRFS),
+};
+
+
+// If this fails, check the array above with network_data.h
+assert_compile(lengthof(_network_udp_packet) == PACKET_UDP_END);
+
+
+void NetworkHandleUDPPacket(Packet *p, struct sockaddr_in *client_addr)
+{
+	byte type;
+
+	/* Fake a client, so we can see when there is an illegal packet */
+	_udp_cs.socket = INVALID_SOCKET;
+	_udp_cs.has_quit = false;
+
+	type = NetworkRecv_uint8(&_udp_cs, p);
+
+	if (type < PACKET_UDP_END && _network_udp_packet[type] != NULL && !_udp_cs.has_quit) {
+		_network_udp_packet[type](p, client_addr);
+	} else {
+		if (!_udp_cs.has_quit) {
+			DEBUG(net, 0, "[udp] received invalid packet type %d", type);
+		} else {
+			DEBUG(net, 0, "[udp] received illegal packet");
+		}
+	}
+}
+
+
+// Close UDP connection
+void NetworkUDPClose(void)
+{
+	DEBUG(net, 1, "[udp] closed listeners");
+
+	if (_network_udp_server) {
+		if (_udp_server_socket != INVALID_SOCKET) {
+			closesocket(_udp_server_socket);
+			_udp_server_socket = INVALID_SOCKET;
+		}
+
+		if (_udp_master_socket != INVALID_SOCKET) {
+			closesocket(_udp_master_socket);
+			_udp_master_socket = INVALID_SOCKET;
+		}
+
+		_network_udp_server = false;
+		_network_udp_broadcast = 0;
+	} else {
+		if (_udp_client_socket != INVALID_SOCKET) {
+			closesocket(_udp_client_socket);
+			_udp_client_socket = INVALID_SOCKET;
+		}
+		_network_udp_broadcast = 0;
+	}
+}
+
+// Broadcast to all ips
+static void NetworkUDPBroadCast(SOCKET udp)
+{
+	Packet* p = NetworkSend_Init(PACKET_UDP_CLIENT_FIND_SERVER);
+	uint i;
+
+	for (i = 0; _broadcast_list[i] != 0; i++) {
+		struct sockaddr_in out_addr;
+
+		out_addr.sin_family = AF_INET;
+		out_addr.sin_port = htons(_network_server_port);
+		out_addr.sin_addr.s_addr = _broadcast_list[i];
+
+		DEBUG(net, 4, "[udp] broadcasting to %s", inet_ntoa(out_addr.sin_addr));
+
+		NetworkSendUDP_Packet(udp, p, &out_addr);
+	}
+
+	free(p);
+}
+
+
+// Request the the server-list from the master server
+void NetworkUDPQueryMasterServer(void)
+{
+	struct sockaddr_in out_addr;
+	Packet *p;
+
+	if (_udp_client_socket == INVALID_SOCKET)
+		if (!NetworkUDPListen(&_udp_client_socket, 0, 0, true))
+			return;
+
+	p = NetworkSend_Init(PACKET_UDP_CLIENT_GET_LIST);
+
+	out_addr.sin_family = AF_INET;
+	out_addr.sin_port = htons(NETWORK_MASTER_SERVER_PORT);
+	out_addr.sin_addr.s_addr = NetworkResolveHost(NETWORK_MASTER_SERVER_HOST);
+
+	// packet only contains protocol version
+	NetworkSend_uint8(p, NETWORK_MASTER_SERVER_VERSION);
+
+	NetworkSendUDP_Packet(_udp_client_socket, p, &out_addr);
+
+	DEBUG(net, 2, "[udp] master server queried at %s:%d", inet_ntoa(out_addr.sin_addr),ntohs(out_addr.sin_port));
+
+	free(p);
+}
+
+// Find all servers
+void NetworkUDPSearchGame(void)
+{
+	// We are still searching..
+	if (_network_udp_broadcast > 0) return;
+
+	// No UDP-socket yet..
+	if (_udp_client_socket == INVALID_SOCKET)
+		if (!NetworkUDPListen(&_udp_client_socket, 0, 0, true))
+			return;
+
+	DEBUG(net, 0, "[udp] searching server");
+
+	NetworkUDPBroadCast(_udp_client_socket);
+	_network_udp_broadcast = 300; // Stay searching for 300 ticks
+}
+
+NetworkGameList *NetworkUDPQueryServer(const char* host, unsigned short port)
+{
+	struct sockaddr_in out_addr;
+	Packet *p;
+	NetworkGameList *item;
+
+	// No UDP-socket yet..
+	if (_udp_client_socket == INVALID_SOCKET)
+		if (!NetworkUDPListen(&_udp_client_socket, 0, 0, true))
+			return NULL;
+
+	out_addr.sin_family = AF_INET;
+	out_addr.sin_port = htons(port);
+	out_addr.sin_addr.s_addr = NetworkResolveHost(host);
+
+	// Clear item in gamelist
+	item = NetworkGameListAddItem(inet_addr(inet_ntoa(out_addr.sin_addr)), ntohs(out_addr.sin_port));
+	memset(&item->info, 0, sizeof(item->info));
+	ttd_strlcpy(item->info.server_name, host, lengthof(item->info.server_name));
+	ttd_strlcpy(item->info.hostname, host, lengthof(item->info.hostname));
+	item->online = false;
+
+	// Init the packet
+	p = NetworkSend_Init(PACKET_UDP_CLIENT_FIND_SERVER);
+
+	NetworkSendUDP_Packet(_udp_client_socket, p, &out_addr);
+
+	free(p);
+
+	UpdateNetworkGameWindow(false);
+	return item;
+}
+
+/* Remove our advertise from the master-server */
+void NetworkUDPRemoveAdvertise(void)
+{
+	struct sockaddr_in out_addr;
+	Packet *p;
+
+	/* Check if we are advertising */
+	if (!_networking || !_network_server || !_network_udp_server) return;
+
+	/* check for socket */
+	if (_udp_master_socket == INVALID_SOCKET)
+		if (!NetworkUDPListen(&_udp_master_socket, _network_server_bind_ip, 0, false))
+			return;
+
+	DEBUG(net, 1, "[udp] removing advertise from master server");
+
+	/* Find somewhere to send */
+	out_addr.sin_family = AF_INET;
+	out_addr.sin_port = htons(NETWORK_MASTER_SERVER_PORT);
+	out_addr.sin_addr.s_addr = NetworkResolveHost(NETWORK_MASTER_SERVER_HOST);
+
+	/* Send the packet */
+	p = NetworkSend_Init(PACKET_UDP_SERVER_UNREGISTER);
+	/* Packet is: Version, server_port */
+	NetworkSend_uint8(p, NETWORK_MASTER_SERVER_VERSION);
+	NetworkSend_uint16(p, _network_server_port);
+	NetworkSendUDP_Packet(_udp_master_socket, p, &out_addr);
+
+	free(p);
+}
+
+/* Register us to the master server
+     This function checks if it needs to send an advertise */
+void NetworkUDPAdvertise(void)
+{
+	struct sockaddr_in out_addr;
+	Packet *p;
+
+	/* Check if we should send an advertise */
+	if (!_networking || !_network_server || !_network_udp_server || !_network_advertise)
+		return;
+
+	/* check for socket */
+	if (_udp_master_socket == INVALID_SOCKET)
+		if (!NetworkUDPListen(&_udp_master_socket, _network_server_bind_ip, 0, false))
+			return;
+
+	if (_network_need_advertise) {
+		_network_need_advertise = false;
+		_network_advertise_retries = ADVERTISE_RETRY_TIMES;
+	} else {
+		/* Only send once every ADVERTISE_NORMAL_INTERVAL ticks */
+		if (_network_advertise_retries == 0) {
+			if ((_network_last_advertise_frame + ADVERTISE_NORMAL_INTERVAL) > _frame_counter)
+				return;
+			_network_advertise_retries = ADVERTISE_RETRY_TIMES;
+		}
+
+		if ((_network_last_advertise_frame + ADVERTISE_RETRY_INTERVAL) > _frame_counter)
+			return;
+	}
+
+	_network_advertise_retries--;
+	_network_last_advertise_frame = _frame_counter;
+
+	/* Find somewhere to send */
+	out_addr.sin_family = AF_INET;
+	out_addr.sin_port = htons(NETWORK_MASTER_SERVER_PORT);
+	out_addr.sin_addr.s_addr = NetworkResolveHost(NETWORK_MASTER_SERVER_HOST);
+
+	DEBUG(net, 1, "[udp] advertising to master server");
+
+	/* Send the packet */
+	p = NetworkSend_Init(PACKET_UDP_SERVER_REGISTER);
+	/* Packet is: WELCOME_MESSAGE, Version, server_port */
+	NetworkSend_string(p, NETWORK_MASTER_SERVER_WELCOME_MESSAGE);
+	NetworkSend_uint8(p, NETWORK_MASTER_SERVER_VERSION);
+	NetworkSend_uint16(p, _network_server_port);
+	NetworkSendUDP_Packet(_udp_master_socket, p, &out_addr);
+
+	free(p);
+}
+
+void NetworkUDPInitialize(void)
+{
+	_udp_client_socket = INVALID_SOCKET;
+	_udp_server_socket = INVALID_SOCKET;
+	_udp_master_socket = INVALID_SOCKET;
+
+	_network_udp_server = false;
+	_network_udp_broadcast = 0;
+}
+
+#endif /* ENABLE_NETWORK */