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/* $Id$ */

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#ifdef ENABLE_NETWORK

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#include "../../stdafx.h"

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#include "../../debug.h"

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#include "../../macros.h"

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#include "../../helpers.hpp"

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#include "packet.h"

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#include "udp.h"

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/**

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 * @file udp.c Basic functions to receive and send UDP packets.

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 */

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/**

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 * Start listening on the given host and port.

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 * @param udp       the place where the (references to the) UDP are stored

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 * @param host      the host (ip) to listen on

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 * @param port      the port to listen on

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 * @param broadcast whether to allow broadcast sending/receiving

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 * @return true if the listening succeeded

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 */

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bool NetworkUDPListen(SOCKET *udp, const uint32 host, const uint16 port, const bool broadcast)

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{

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	struct sockaddr_in sin;

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	/* Make sure socket is closed */

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	NetworkUDPClose(udp);

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	*udp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

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	if (*udp == INVALID_SOCKET) {

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		DEBUG(net, 0, "[udp] failed to start UDP listener");

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		return false;

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	}

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	/* set nonblocking mode for socket */

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	{

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		unsigned long blocking = 1;

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#ifndef BEOS_NET_SERVER

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		ioctlsocket(*udp, FIONBIO, &blocking);

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#else

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		setsockopt(*udp, SOL_SOCKET, SO_NONBLOCK, &blocking, NULL);

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#endif

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	}

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	sin.sin_family = AF_INET;

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	/* Listen on all IPs */

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	sin.sin_addr.s_addr = host;

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	sin.sin_port = htons(port);

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	if (bind(*udp, (struct sockaddr*)&sin, sizeof(sin)) != 0) {

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		DEBUG(net, 0, "[udp] bind failed on %s:%i", inet_ntoa(*(struct in_addr *)&host), port);

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		return false;

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	}

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	if (broadcast) {

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		/* Enable broadcast */

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		unsigned long val = 1;

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#ifndef BEOS_NET_SERVER // will work around this, some day; maybe.

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		setsockopt(*udp, SOL_SOCKET, SO_BROADCAST, (char *) &val , sizeof(val));

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#endif

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	}

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	DEBUG(net, 1, "[udp] listening on port %s:%d", inet_ntoa(*(struct in_addr *)&host), port);

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	return true;

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}

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/**

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 * Close the given UDP socket

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 * @param udp the socket to close

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 */

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void NetworkUDPClose(SOCKET *udp)

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{

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	if (*udp == INVALID_SOCKET) return;

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	closesocket(*udp);

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	*udp = INVALID_SOCKET;

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}

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/**

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 * Send a packet over UDP

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 * @param udp  the socket to send over

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 * @param p    the packet to send

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 * @param recv the receiver (target) of the packet

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 */

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void NetworkSendUDP_Packet(const SOCKET udp, Packet *p, const struct sockaddr_in *recv)

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{

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	int res;

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	NetworkSend_FillPacketSize(p);

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	/* Send the buffer */

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	res = sendto(udp, (const char*)p->buffer, p->size, 0, (struct sockaddr *)recv, sizeof(*recv));

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	/* Check for any errors, but ignore it otherwise */

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	if (res == -1) DEBUG(net, 1, "[udp] sendto failed with: %i", GET_LAST_ERROR());

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}

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/**

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 * Receive a packet at UDP level

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 * @param udp the socket to receive the packet on

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 */

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void NetworkUDPReceive(const SOCKET udp)

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{

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	struct sockaddr_in client_addr;

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	socklen_t client_len;

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	int nbytes;

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	Packet p;

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	int packet_len;

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	packet_len = sizeof(p.buffer);

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	client_len = sizeof(client_addr);

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	/* Try to receive anything */

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	nbytes = recvfrom(udp, (char*)p.buffer, packet_len, 0, (struct sockaddr *)&client_addr, &client_len);

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	/* We got some bytes for the base header of the packet. */

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	if (nbytes > 2) {

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		NetworkRecv_ReadPacketSize(&p);

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		/* If the size does not match the packet must be corrupted.

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		 * Otherwise it will be marked as corrupted later on. */

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		if (nbytes != p.size) {

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			DEBUG(net, 1, "received a packet with mismatching size from %s:%d",

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					inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));

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			return;

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		}

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		/* Put the position on the right place */

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		p.pos = 2;

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		p.next = NULL;

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		/* Handle the packet */

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		NetworkHandleUDPPacket(udp, &p, &client_addr);

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	}

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}

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/**

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 * Serializes the GRFIdentifier (GRF ID and MD5 checksum) to the packet

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 * @param p the packet to write the data to

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 * @param c the configuration to write the GRF ID and MD5 checksum from

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 */

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void NetworkSend_GRFIdentifier(Packet *p, const GRFConfig *c)

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{

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	uint j;

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	NetworkSend_uint32(p, c->grfid);

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	for (j = 0; j < sizeof(c->md5sum); j++) {

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		NetworkSend_uint8 (p, c->md5sum[j]);

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	}

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}

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/**

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 * Deserializes the GRFIdentifier (GRF ID and MD5 checksum) from the packet

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 * @param cs the client state (for closing connect on out-of-bounds reading etc)

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 * @param p  the packet to read the data from

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 * @param c  the configuration to write the GRF ID and MD5 checksum to

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 */

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void NetworkRecv_GRFIdentifier(NetworkClientState *cs, Packet *p, GRFConfig *c)

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{

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	uint j;

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	c->grfid = NetworkRecv_uint32(cs, p);

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	for (j = 0; j < sizeof(c->md5sum); j++) {

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		c->md5sum[j] = NetworkRecv_uint8(cs, p);

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	}

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}

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/**

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 * Serializes the NetworkGameInfo struct to the packet

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 * @param p    the packet to write the data to

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 * @param info the NetworkGameInfo struct to serialize

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 */

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void NetworkSend_NetworkGameInfo(Packet *p, const NetworkGameInfo *info)

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{

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	NetworkSend_uint8 (p, NETWORK_GAME_INFO_VERSION);

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	/*

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	 *              Please observe the order.

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	 * The parts must be read in the same order as they are sent!

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	 */

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	/* Update the documentation in udp.h on changes

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	 * to the NetworkGameInfo wire-protocol! */

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	/* NETWORK_GAME_INFO_VERSION = 4 */

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	{

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		/* Only send the GRF Identification (GRF_ID and MD5 checksum) of

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		 * the GRFs that are needed, i.e. the ones that the server has

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		 * selected in the NewGRF GUI and not the ones that are used due

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		 * to the fact that they are in [newgrf-static] in openttd.cfg */

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		const GRFConfig *c;

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		uint count = 0;

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		/* Count number of GRFs to send information about */

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

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			if (!HASBIT(c->flags, GCF_STATIC)) count++;

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		}

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		NetworkSend_uint8 (p, count); // Send number of GRFs

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		/* Send actual GRF Identifications */

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

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			if (!HASBIT(c->flags, GCF_STATIC)) NetworkSend_GRFIdentifier(p, c);

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		}

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	}

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	/* NETWORK_GAME_INFO_VERSION = 3 */

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	NetworkSend_uint32(p, info->game_date);

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	NetworkSend_uint32(p, info->start_date);

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	/* NETWORK_GAME_INFO_VERSION = 2 */

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	NetworkSend_uint8 (p, info->companies_max);

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	NetworkSend_uint8 (p, info->companies_on);

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	NetworkSend_uint8 (p, info->spectators_max);

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	/* NETWORK_GAME_INFO_VERSION = 1 */

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	NetworkSend_string(p, info->server_name);

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	NetworkSend_string(p, info->server_revision);

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	NetworkSend_uint8 (p, info->server_lang);

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	NetworkSend_uint8 (p, info->use_password);

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	NetworkSend_uint8 (p, info->clients_max);

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	NetworkSend_uint8 (p, info->clients_on);

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	NetworkSend_uint8 (p, info->spectators_on);

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	NetworkSend_string(p, info->map_name);

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	NetworkSend_uint16(p, info->map_width);

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	NetworkSend_uint16(p, info->map_height);

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	NetworkSend_uint8 (p, info->map_set);

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	NetworkSend_uint8 (p, info->dedicated);

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}

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/**

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 * Deserializes the NetworkGameInfo struct from the packet

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 * @param cs   the client state (for closing connect on out-of-bounds reading etc)

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 * @param p    the packet to read the data from

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 * @param info the NetworkGameInfo to deserialize into

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 */

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void NetworkRecv_NetworkGameInfo(NetworkClientState *cs, Packet *p, NetworkGameInfo *info)

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{

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	info->game_info_version = NetworkRecv_uint8(cs, p);

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	/*

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	 *              Please observe the order.

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	 * The parts must be read in the same order as they are sent!

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	 */

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	/* Update the documentation in udp.h on changes

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	 * to the NetworkGameInfo wire-protocol! */

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	switch (info->game_info_version) {

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		case 4: {

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			uint i;

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			uint num_grfs = NetworkRecv_uint8(cs, p);

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

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				NetworkRecv_GRFIdentifier(cs, p, c);

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				HandleIncomingNetworkGameInfoGRFConfig(c);

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				/* Append GRFConfig to the list */

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				*dst = c;

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				dst = &c->next;

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			}

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		} /* Fallthrough */

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		case 3:

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			info->game_date      = NetworkRecv_uint32(cs, p);

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			info->start_date     = NetworkRecv_uint32(cs, p);

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			/* Fallthrough */

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		case 2:

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			info->companies_max  = NetworkRecv_uint8 (cs, p);

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			info->companies_on   = NetworkRecv_uint8 (cs, p);

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			info->spectators_max = NetworkRecv_uint8 (cs, p);

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			/* Fallthrough */

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		case 1:

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			NetworkRecv_string(cs, p, info->server_name,     sizeof(info->server_name));

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			NetworkRecv_string(cs, p, info->server_revision, sizeof(info->server_revision));

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			info->server_lang    = NetworkRecv_uint8 (cs, p);

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			info->use_password   = NetworkRecv_uint8 (cs, p);

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			info->clients_max    = NetworkRecv_uint8 (cs, p);

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			info->clients_on     = NetworkRecv_uint8 (cs, p);

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			info->spectators_on  = NetworkRecv_uint8 (cs, p);

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			if (info->game_info_version < 3) { // 16 bits dates got scrapped and are read earlier

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				info->game_date    = NetworkRecv_uint16(cs, p) + DAYS_TILL_ORIGINAL_BASE_YEAR;

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				info->start_date   = NetworkRecv_uint16(cs, p) + DAYS_TILL_ORIGINAL_BASE_YEAR;

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			}

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			NetworkRecv_string(cs, p, info->map_name, sizeof(info->map_name));

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			info->map_width      = NetworkRecv_uint16(cs, p);

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			info->map_height     = NetworkRecv_uint16(cs, p);

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			info->map_set        = NetworkRecv_uint8 (cs, p);

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			info->dedicated      = (NetworkRecv_uint8 (cs, p) != 0);

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	}

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}

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#endif /* ENABLE_NETWORK */