1

/* $Id$ */

     2

     3

/**

     4

 * @file core/udp.cpp Basic functions to receive and send UDP packets.

     5

 */

     6

     7

#ifdef ENABLE_NETWORK

     8

     9

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

    10

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

    11

#include "../../core/bitmath_func.hpp"

    12

#include "../../core/math_func.hpp"

    13

#include "../../core/alloc_func.hpp"

    14

#include "../../date_func.h"

    15

#include "packet.h"

    16

#include "udp.h"

    17

    18

/**

    19

 * Start listening on the given host and port.

    20

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

    21

 * @param port      the port to listen on

    22

 * @param broadcast whether to allow broadcast sending/receiving

    23

 * @return true if the listening succeeded

    24

 */

    25

bool NetworkUDPSocketHandler::Listen(const uint32 host, const uint16 port, const bool broadcast)

    26

{

    27

	struct sockaddr_in sin;

    28

    29

	/* Make sure socket is closed */

    30

	this->Close();

    31

    32

	this->sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

    33

	if (!this->IsConnected()) {

    34

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

    35

		return false;

    36

	}

    37

    38

	SetNonBlocking(this->sock);

    39

    40

	sin.sin_family = AF_INET;

    41

	/* Listen on all IPs */

    42

	sin.sin_addr.s_addr = host;

    43

	sin.sin_port = htons(port);

    44

    45

	if (bind(this->sock, (struct sockaddr*)&sin, sizeof(sin)) != 0) {

    46

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

    47

		return false;

    48

	}

    49

    50

	if (broadcast) {

    51

		/* Enable broadcast */

    52

		unsigned long val = 1;

    53

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

    54

		setsockopt(this->sock, SOL_SOCKET, SO_BROADCAST, (char *) &val , sizeof(val));

    55

#endif

    56

	}

    57

    58

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

    59

    60

	return true;

    61

}

    62

    63

/**

    64

 * Close the given UDP socket

    65

 */

    66

void NetworkUDPSocketHandler::Close()

    67

{

    68

	if (!this->IsConnected()) return;

    69

    70

	closesocket(this->sock);

    71

	this->sock = INVALID_SOCKET;

    72

}

    73

    74

NetworkRecvStatus NetworkUDPSocketHandler::CloseConnection()

    75

{

    76

	this->has_quit = true;

    77

	return NETWORK_RECV_STATUS_OKAY;

    78

}

    79

    80

/**

    81

 * Send a packet over UDP

    82

 * @param p    the packet to send

    83

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

    84

 */

    85

void NetworkUDPSocketHandler::SendPacket(Packet *p, const struct sockaddr_in *recv)

    86

{

    87

	int res;

    88

    89

	p->PrepareToSend();

    90

    91

	/* Send the buffer */

    92

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

    93

    94

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

    95

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

    96

}

    97

    98

/**

    99

 * Receive a packet at UDP level

   100

 */

   101

void NetworkUDPSocketHandler::ReceivePackets()

   102

{

   103

	struct sockaddr_in client_addr;

   104

	socklen_t client_len;

   105

	int nbytes;

   106

	Packet p(this);

   107

	int packet_len;

   108

   109

	if (!this->IsConnected()) return;

   110

   111

	packet_len = sizeof(p.buffer);

   112

	client_len = sizeof(client_addr);

   113

   114

	/* Try to receive anything */

   115

	SetNonBlocking(this->sock); // Some OSes seem to lose the non-blocking status of the socket

   116

	nbytes = recvfrom(this->sock, (char*)p.buffer, packet_len, 0, (struct sockaddr *)&client_addr, &client_len);

   117

   118

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

   119

	if (nbytes > 2) {

   120

		p.PrepareToRead();

   121

   122

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

   123

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

   124

		if (nbytes != p.size) {

   125

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

   126

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

   127

   128

			return;

   129

		}

   130

   131

		/* Handle the packet */

   132

		this->HandleUDPPacket(&p, &client_addr);

   133

	}

   134

}

   135

   136

   137

/**

   138

 * Serializes the NetworkGameInfo struct to the packet

   139

 * @param p    the packet to write the data to

   140

 * @param info the NetworkGameInfo struct to serialize

   141

 */

   142

void NetworkUDPSocketHandler::Send_NetworkGameInfo(Packet *p, const NetworkGameInfo *info)

   143

{

   144

	p->Send_uint8 (NETWORK_GAME_INFO_VERSION);

   145

   146

	/*

   147

	 *              Please observe the order.

   148

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

   149

	 */

   150

   151

	/* Update the documentation in udp.h on changes

   152

	 * to the NetworkGameInfo wire-protocol! */

   153

   154

	/* NETWORK_GAME_INFO_VERSION = 4 */

   155

	{

   156

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

   157

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

   158

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

   159

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

   160

		const GRFConfig *c;

   161

		uint count = 0;

   162

   163

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

   164

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

   165

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

   166

		}

   167

		p->Send_uint8 (count); // Send number of GRFs

   168

   169

		/* Send actual GRF Identifications */

   170

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

   171

			if (!HasBit(c->flags, GCF_STATIC)) this->Send_GRFIdentifier(p, c);

   172

		}

   173

	}

   174

   175

	/* NETWORK_GAME_INFO_VERSION = 3 */

   176

	p->Send_uint32(info->game_date);

   177

	p->Send_uint32(info->start_date);

   178

   179

	/* NETWORK_GAME_INFO_VERSION = 2 */

   180

	p->Send_uint8 (info->companies_max);

   181

	p->Send_uint8 (info->companies_on);

   182

	p->Send_uint8 (info->spectators_max);

   183

   184

	/* NETWORK_GAME_INFO_VERSION = 1 */

   185

	p->Send_string(info->server_name);

   186

	p->Send_string(info->server_revision);

   187

	p->Send_uint8 (info->server_lang);

   188

	p->Send_bool  (info->use_password);

   189

	p->Send_uint8 (info->clients_max);

   190

	p->Send_uint8 (info->clients_on);

   191

	p->Send_uint8 (info->spectators_on);

   192

	p->Send_string(info->map_name);

   193

	p->Send_uint16(info->map_width);

   194

	p->Send_uint16(info->map_height);

   195

	p->Send_uint8 (info->map_set);

   196

	p->Send_bool  (info->dedicated);

   197

}

   198

   199

/**

   200

 * Deserializes the NetworkGameInfo struct from the packet

   201

 * @param p    the packet to read the data from

   202

 * @param info the NetworkGameInfo to deserialize into

   203

 */

   204

void NetworkUDPSocketHandler::Recv_NetworkGameInfo(Packet *p, NetworkGameInfo *info)

   205

{

   206

	static const Date MAX_DATE = ConvertYMDToDate(MAX_YEAR, 11, 31); // December is month 11

   207

   208

	info->game_info_version = p->Recv_uint8();

   209

   210

	/*

   211

	 *              Please observe the order.

   212

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

   213

	 */

   214

   215

	/* Update the documentation in udp.h on changes

   216

	 * to the NetworkGameInfo wire-protocol! */

   217

   218

	switch (info->game_info_version) {

   219

		case 4: {

   220

			GRFConfig **dst = &info->grfconfig;

   221

			uint i;

   222

			uint num_grfs = p->Recv_uint8();

   223

   224

			/* Broken/bad data. It cannot have that many NewGRFs. */

   225

			if (num_grfs > NETWORK_MAX_GRF_COUNT) return;

   226

   227

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

   228

				GRFConfig *c = CallocT<GRFConfig>(1);

   229

				this->Recv_GRFIdentifier(p, c);

   230

				this->HandleIncomingNetworkGameInfoGRFConfig(c);

   231

   232

				/* Append GRFConfig to the list */

   233

				*dst = c;

   234

				dst = &c->next;

   235

			}

   236

		} /* Fallthrough */

   237

		case 3:

   238

			info->game_date      = Clamp(p->Recv_uint32(), 0, MAX_DATE);

   239

			info->start_date     = Clamp(p->Recv_uint32(), 0, MAX_DATE);

   240

			/* Fallthrough */

   241

		case 2:

   242

			info->companies_max  = p->Recv_uint8 ();

   243

			info->companies_on   = p->Recv_uint8 ();

   244

			info->spectators_max = p->Recv_uint8 ();

   245

			/* Fallthrough */

   246

		case 1:

   247

			p->Recv_string(info->server_name,     sizeof(info->server_name));

   248

			p->Recv_string(info->server_revision, sizeof(info->server_revision));

   249

			info->server_lang    = p->Recv_uint8 ();

   250

			info->use_password   = p->Recv_bool  ();

   251

			info->clients_max    = p->Recv_uint8 ();

   252

			info->clients_on     = p->Recv_uint8 ();

   253

			info->spectators_on  = p->Recv_uint8 ();

   254

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

   255

				info->game_date    = p->Recv_uint16() + DAYS_TILL_ORIGINAL_BASE_YEAR;

   256

				info->start_date   = p->Recv_uint16() + DAYS_TILL_ORIGINAL_BASE_YEAR;

   257

			}

   258

			p->Recv_string(info->map_name, sizeof(info->map_name));

   259

			info->map_width      = p->Recv_uint16();

   260

			info->map_height     = p->Recv_uint16();

   261

			info->map_set        = p->Recv_uint8 ();

   262

			info->dedicated      = p->Recv_bool  ();

   263

   264

			if (info->server_lang >= NETWORK_NUM_LANGUAGES)  info->server_lang = 0;

   265

			if (info->map_set     >= NETWORK_NUM_LANDSCAPES) info->map_set     = 0;

   266

	}

   267

}

   268

   269

/**

   270

 * Defines a simple (switch) case for each network packet

   271

 * @param type the packet type to create the case for

   272

 */

   273

#define UDP_COMMAND(type) case type: this->NetworkPacketReceive_ ## type ## _command(p, client_addr); break;

   274

   275

/**

   276

 * Handle an incoming packets by sending it to the correct function.

   277

 * @param p the received packet

   278

 * @param client_addr the sender of the packet

   279

 */

   280

void NetworkUDPSocketHandler::HandleUDPPacket(Packet *p, const struct sockaddr_in *client_addr)

   281

{

   282

	PacketUDPType type;

   283

   284

	/* New packet == new client, which has not quit yet */

   285

	this->has_quit = false;

   286

   287

	type = (PacketUDPType)p->Recv_uint8();

   288

   289

	switch (this->HasClientQuit() ? PACKET_UDP_END : type) {

   290

		UDP_COMMAND(PACKET_UDP_CLIENT_FIND_SERVER);

   291

		UDP_COMMAND(PACKET_UDP_SERVER_RESPONSE);

   292

		UDP_COMMAND(PACKET_UDP_CLIENT_DETAIL_INFO);

   293

		UDP_COMMAND(PACKET_UDP_SERVER_DETAIL_INFO);

   294

		UDP_COMMAND(PACKET_UDP_SERVER_REGISTER);

   295

		UDP_COMMAND(PACKET_UDP_MASTER_ACK_REGISTER);

   296

		UDP_COMMAND(PACKET_UDP_CLIENT_GET_LIST);

   297

		UDP_COMMAND(PACKET_UDP_MASTER_RESPONSE_LIST);

   298

		UDP_COMMAND(PACKET_UDP_SERVER_UNREGISTER);

   299

		UDP_COMMAND(PACKET_UDP_CLIENT_GET_NEWGRFS);

   300

		UDP_COMMAND(PACKET_UDP_SERVER_NEWGRFS);

   301

   302

		default:

   303

			if (this->HasClientQuit()) {

   304

				DEBUG(net, 0, "[udp] received invalid packet type %d from %s:%d", type,  inet_ntoa(client_addr->sin_addr), ntohs(client_addr->sin_port));

   305

			} else {

   306

				DEBUG(net, 0, "[udp] received illegal packet from %s:%d", inet_ntoa(client_addr->sin_addr), ntohs(client_addr->sin_port));

   307

			}

   308

			break;

   309

	}

   310

}

   311

   312

/**

   313

 * Create stub implementations for all receive commands that only

   314

 * show a warning that the given command is not available for the

   315

 * socket where the packet came from.

   316

 * @param type the packet type to create the stub for

   317

 */

   318

#define DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(type) \

   319

void NetworkUDPSocketHandler::NetworkPacketReceive_## type ##_command(\

   320

		Packet *p, const struct sockaddr_in *client_addr) { \

   321

	DEBUG(net, 0, "[udp] received packet type %d on wrong port from %s:%d", \

   322

			type, inet_ntoa(client_addr->sin_addr), ntohs(client_addr->sin_port)); \

   323

}

   324

   325

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_FIND_SERVER);

   326

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_RESPONSE);

   327

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_DETAIL_INFO);

   328

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_DETAIL_INFO);

   329

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_REGISTER);

   330

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_MASTER_ACK_REGISTER);

   331

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_GET_LIST);

   332

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_MASTER_RESPONSE_LIST);

   333

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_UNREGISTER);

   334

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_CLIENT_GET_NEWGRFS);

   335

DEFINE_UNAVAILABLE_UDP_RECEIVE_COMMAND(PACKET_UDP_SERVER_NEWGRFS);

   336

   337

#endif /* ENABLE_NETWORK */