1

#include "stdafx.h"

     2

#include "network_data.h"

     3

     4

// Is the network enabled?

     5

#ifdef ENABLE_NETWORK

     6

     7

#include "table/strings.h"

     8

#include "network_client.h"

     9

#include "command.h"

    10

#include "callback_table.h"

    11

    12

// This files handles the send/receive of all packets

    13

    14

// Create a packet for sending

    15

Packet *NetworkSend_Init(PacketType type)

    16

{

    17

	Packet *packet = malloc(sizeof(Packet));

    18

	// An error is inplace here, because it simply means we ran out of memory.

    19

	if (packet == NULL) error("Failed to allocate Packet");

    20

    21

	// Skip the size so we can write that in before sending the packet

    22

	packet->size = sizeof(packet->size);

    23

	packet->buffer[packet->size++] = type;

    24

	packet->pos = 0;

    25

    26

	return packet;

    27

}

    28

    29

// The next couple of functions make sure we can send

    30

//  uint8, uint16, uint32 and uint64 endian-safe

    31

//  over the network. The order it uses is:

    32

//

    33

//  1 2 3 4

    34

//

    35

    36

void NetworkSend_uint8(Packet *packet, uint8 data)

    37

{

    38

	assert(packet->size < sizeof(packet->buffer) - sizeof(data));

    39

	packet->buffer[packet->size++] = data & 0xFF;

    40

}

    41

    42

void NetworkSend_uint16(Packet *packet, uint16 data)

    43

{

    44

	assert(packet->size < sizeof(packet->buffer) - sizeof(data));

    45

	packet->buffer[packet->size++] = data & 0xFF;

    46

	packet->buffer[packet->size++] = (data >> 8) & 0xFF;

    47

}

    48

    49

void NetworkSend_uint32(Packet *packet, uint32 data)

    50

{

    51

	assert(packet->size < sizeof(packet->buffer) - sizeof(data));

    52

	packet->buffer[packet->size++] = data & 0xFF;

    53

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    54

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    55

	packet->buffer[packet->size++] = (data >> 8) & 0xFF;

    56

}

    57

    58

void NetworkSend_uint64(Packet *packet, uint64 data)

    59

{

    60

	assert(packet->size < sizeof(packet->buffer) - sizeof(data));

    61

	packet->buffer[packet->size++] = data & 0xFF;

    62

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    63

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    64

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    65

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    66

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    67

	packet->buffer[packet->size++] = (data >>= 8) & 0xFF;

    68

	packet->buffer[packet->size++] = (data >> 8) & 0xFF;

    69

}

    70

    71

// Sends a string over the network. It sends out

    72

//  the string + '\0'. No size-byte or something.

    73

void NetworkSend_string(Packet *packet, const char* data)

    74

{

    75

	assert(data != NULL);

    76

	assert(packet->size < sizeof(packet->buffer) - strlen(data) - 1);

    77

	while ((packet->buffer[packet->size++] = *data++) != '\0') {}

    78

}

    79

    80

// If PacketSize changes of size, you have to change the 2 packet->size

    81

//   lines below matching the size of packet->size/PacketSize!

    82

// (line 'packet->buffer[0] = packet->size & 0xFF;'  and below)

    83

assert_compile(sizeof(PacketSize) == 2);

    84

    85

// This function puts the packet in the send-queue and it is send

    86

//  as soon as possible

    87

// (that is: the next tick, or maybe one tick later if the

    88

//   OS-network-buffer is full)

    89

void NetworkSend_Packet(Packet *packet, NetworkClientState *cs)

    90

{

    91

	Packet *p;

    92

	assert(packet != NULL);

    93

    94

	packet->pos = 0;

    95

	packet->next = NULL;

    96

    97

	packet->buffer[0] = packet->size & 0xFF;

    98

	packet->buffer[1] = packet->size >> 8;

    99

   100

	// Locate last packet buffered for the client

   101

	p = cs->packet_queue;

   102

	if (p == NULL) {

   103

		// No packets yet

   104

		cs->packet_queue = packet;

   105

	} else {

   106

		// Skip to the last packet

   107

		while (p->next != NULL) p = p->next;

   108

		p->next = packet;

   109

	}

   110

}

   111

   112

// Functions to help NetworkRecv_Packet/NetworkSend_Packet a bit

   113

//  A socket can make errors. When that happens

   114

//  this handles what to do.

   115

// For clients: close connection and drop back to main-menu

   116

// For servers: close connection and that is it

   117

NetworkRecvStatus CloseConnection(NetworkClientState *cs)

   118

{

   119

	NetworkCloseClient(cs);

   120

   121

	// Clients drop back to the main menu

   122

	if (!_network_server) {

   123

		_switch_mode = SM_MENU;

   124

		_networking = false;

   125

		_switch_mode_errorstr = STR_NETWORK_ERR_LOSTCONNECTION;

   126

   127

		return NETWORK_RECV_STATUS_CONN_LOST;

   128

	}

   129

   130

	return NETWORK_RECV_STATUS_OKAY;

   131

}

   132

   133

// Sends all the buffered packets out for this client

   134

//  it stops when:

   135

//   1) all packets are send (queue is empty)

   136

//   2) the OS reports back that it can not send any more

   137

//        data right now (full network-buffer, it happens ;))

   138

//   3) sending took too long

   139

bool NetworkSend_Packets(NetworkClientState *cs)

   140

{

   141

	ssize_t res;

   142

	Packet *p;

   143

   144

	// We can not write to this socket!!

   145

	if (!cs->writable) return false;

   146

	if (cs->socket == INVALID_SOCKET) return false;

   147

   148

	p = cs->packet_queue;

   149

	while (p != NULL) {

   150

		res = send(cs->socket, p->buffer + p->pos, p->size - p->pos, 0);

   151

		if (res == -1) {

   152

			int err = GET_LAST_ERROR();

   153

			if (err != EWOULDBLOCK) {

   154

				// Something went wrong.. close client!

   155

				DEBUG(net, 0) ("[NET] send() failed with error %d", err);

   156

				CloseConnection(cs);

   157

				return false;

   158

			}

   159

			return true;

   160

		}

   161

		if (res == 0) {

   162

			// Client/server has left us :(

   163

			CloseConnection(cs);

   164

			return false;

   165

		}

   166

   167

		p->pos += res;

   168

   169

		// Is this packet sent?

   170

		if (p->pos == p->size) {

   171

			// Go to the next packet

   172

			cs->packet_queue = p->next;

   173

			free(p);

   174

			p = cs->packet_queue;

   175

		} else

   176

			return true;

   177

	}

   178

   179

	return true;

   180

}

   181

   182

   183

// Receiving commands

   184

// Again, the next couple of functions are endian-safe

   185

//  see the comment around NetworkSend_uint8 for more info.

   186

uint8 NetworkRecv_uint8(Packet *packet)

   187

{

   188

	return packet->buffer[packet->pos++];

   189

}

   190

   191

uint16 NetworkRecv_uint16(Packet *packet)

   192

{

   193

	uint16 n;

   194

	n  = (uint16)packet->buffer[packet->pos++];

   195

	n += (uint16)packet->buffer[packet->pos++] << 8;

   196

	return n;

   197

}

   198

   199

uint32 NetworkRecv_uint32(Packet *packet)

   200

{

   201

	uint32 n;

   202

	n  = (uint32)packet->buffer[packet->pos++];

   203

	n += (uint32)packet->buffer[packet->pos++] << 8;

   204

	n += (uint32)packet->buffer[packet->pos++] << 16;

   205

	n += (uint32)packet->buffer[packet->pos++] << 24;

   206

	return n;

   207

}

   208

   209

uint64 NetworkRecv_uint64(Packet *packet)

   210

{

   211

	uint64 n;

   212

	n  = (uint64)packet->buffer[packet->pos++];

   213

	n += (uint64)packet->buffer[packet->pos++] << 8;

   214

	n += (uint64)packet->buffer[packet->pos++] << 16;

   215

	n += (uint64)packet->buffer[packet->pos++] << 24;

   216

	n += (uint64)packet->buffer[packet->pos++] << 32;

   217

	n += (uint64)packet->buffer[packet->pos++] << 40;

   218

	n += (uint64)packet->buffer[packet->pos++] << 48;

   219

	n += (uint64)packet->buffer[packet->pos++] << 56;

   220

	return n;

   221

}

   222

   223

// Reads a string till it finds a '\0' in the stream

   224

void NetworkRecv_string(Packet *p, char* buffer, size_t size)

   225

{

   226

	int pos;

   227

	pos = p->pos;

   228

	while (--size > 0 && pos < p->size && (*buffer++ = p->buffer[pos++]) != '\0') {}

   229

	if (size == 0 || pos == p->size)

   230

	{

   231

		*buffer = '\0';

   232

		// If size was sooner to zero then the string in the stream

   233

		//  skip till the \0, so the packet can be read out correctly for the rest

   234

		while (pos < p->size && p->buffer[pos] != '\0') ++pos;

   235

		++pos;

   236

	}

   237

	p->pos = pos;

   238

}

   239

   240

// If PacketSize changes of size, you have to change the 2 packet->size

   241

//   lines below matching the size of packet->size/PacketSize!

   242

// (the line: 'p->size = (uint16)p->buffer[0];' and below)

   243

assert_compile(sizeof(PacketSize) == 2);

   244

   245

Packet *NetworkRecv_Packet(NetworkClientState *cs, NetworkRecvStatus *status)

   246

{

   247

	ssize_t res;

   248

	Packet *p;

   249

   250

	*status = NETWORK_RECV_STATUS_OKAY;

   251

   252

	if (cs->socket == INVALID_SOCKET) return NULL;

   253

   254

	if (cs->packet_recv == NULL) {

   255

		cs->packet_recv = malloc(sizeof(Packet));

   256

		if (cs->packet_recv == NULL) error("Failed to allocate packet");

   257

		// Set pos to zero!

   258

		cs->packet_recv->pos = 0;

   259

		cs->packet_recv->size = 0; // Can be ommited, just for safety reasons

   260

	}

   261

   262

	p = cs->packet_recv;

   263

   264

	// Read packet size

   265

	if (p->pos < sizeof(PacketSize)) {

   266

		while (p->pos < sizeof(PacketSize)) {

   267

			// Read the size of the packet

   268

			res = recv(cs->socket, p->buffer + p->pos, sizeof(PacketSize) - p->pos, 0);

   269

			if (res == -1) {

   270

				int err = GET_LAST_ERROR();

   271

				if (err != EWOULDBLOCK) {

   272

					// Something went wrong..

   273

					if (err != 104) // 104 is Connection Reset by Peer

   274

						DEBUG(net, 0) ("[NET] recv() failed with error %d", err);

   275

					*status = CloseConnection(cs);

   276

					return NULL;

   277

				}

   278

				// Connection would block, so stop for now

   279

				return NULL;

   280

			}

   281

			if (res == 0) {

   282

				// Client/server has left us :(

   283

				*status = CloseConnection(cs);

   284

				return NULL;

   285

			}

   286

			p->pos += res;

   287

		}

   288

   289

		p->size = (uint16)p->buffer[0];

   290

		p->size += (uint16)p->buffer[1] << 8;

   291

   292

		if (p->size > SEND_MTU) {

   293

			*status = CloseConnection(cs);

   294

			return NULL;

   295

		}

   296

	}

   297

   298

	// Read rest of packet

   299

	while (p->pos < p->size) {

   300

		res = recv(cs->socket, p->buffer + p->pos, p->size - p->pos, 0);

   301

		if (res == -1) {

   302

			int err = GET_LAST_ERROR();

   303

			if (err != EWOULDBLOCK) {

   304

				// Something went wrong..

   305

				if (err != 104) // 104 is Connection Reset by Peer

   306

					DEBUG(net, 0) ("[NET] recv() failed with error %d", err);

   307

				*status = CloseConnection(cs);

   308

				return NULL;

   309

			}

   310

			// Connection would block

   311

			return NULL;

   312

		}

   313

		if (res == 0) {

   314

			// Client/server has left us :(

   315

			*status = CloseConnection(cs);

   316

			return NULL;

   317

		}

   318

   319

		p->pos += res;

   320

	}

   321

   322

	// We have a complete packet, return it!

   323

	p->pos = 2;

   324

	p->next = NULL; // Should not be needed, but who knows...

   325

   326

	// Prepare for receiving a new packet

   327

	cs->packet_recv = NULL;

   328

   329

	return p;

   330

}

   331

   332

// Add a command to the local command queue

   333

void NetworkAddCommandQueue(NetworkClientState *cs, CommandPacket *cp)

   334

{

   335

	CommandPacket *new_cp = malloc(sizeof(CommandPacket));

   336

   337

	*new_cp = *cp;

   338

   339

	if (cs->command_queue == NULL)

   340

		cs->command_queue = new_cp;

   341

	else {

   342

		CommandPacket *c = cs->command_queue;

   343

		while (c->next != NULL) c = c->next;

   344

		c->next = new_cp;

   345

	}

   346

}

   347

   348

// If this fails, make sure you change the following line below:

   349

//   'memcpy(qp->dp, _decode_parameters, 10 * sizeof(uint32));'

   350

// Also, in network_data.h, change the size of CommandPacket->dp!

   351

// (this protection is there to make sure in network.h dp is of the right size!)

   352

assert_compile(sizeof(_decode_parameters) == 20 * sizeof(uint32));

   353

   354

// Prepare a DoCommand to be send over the network

   355

void NetworkSend_Command(uint32 tile, uint32 p1, uint32 p2, uint32 cmd, CommandCallback *callback)

   356

{

   357

	CommandPacket *c = malloc(sizeof(CommandPacket));

   358

	byte temp_callback;

   359

   360

	c->player = _local_player;

   361

	c->next = NULL;

   362

	c->tile = tile;

   363

	c->p1 = p1;

   364

	c->p2 = p2;

   365

	c->cmd = cmd;

   366

	c->callback = 0;

   367

   368

	temp_callback = 0;

   369

   370

	while (temp_callback < _callback_table_count && _callback_table[temp_callback] != callback)

   371

		temp_callback++;

   372

	if (temp_callback == _callback_table_count) {

   373

		DEBUG(net, 0) ("[NET] Unknown callback. (Pointer: %p) No callback sent.", callback);

   374

		temp_callback = 0; /* _callback_table[0] == NULL */

   375

	}

   376

   377

	if (_network_server) {

   378

		// We are the server, so set the command to be executed next possible frame

   379

		c->frame = _frame_counter_max + 1;

   380

	} else {

   381

		c->frame = 0; // The client can't tell which frame, so just make it 0

   382

	}

   383

   384

	// Copy the _decode_parameters to dp

   385

	memcpy(c->dp, _decode_parameters, 20 * sizeof(uint32));

   386

   387

	if (_network_server) {

   388

		// If we are the server, we queue the command in our 'special' queue.

   389

		//   In theory, we could execute the command right away, but then the

   391

		//   So to keep the game fair, we delay the command with 1 tick

   392

		//   which gives about the same speed as most clients.

   393

		NetworkClientState *cs;

   394

   395

		// And we queue it for delivery to the clients

   396

		FOR_ALL_CLIENTS(cs) {

   397

			if (cs->status > STATUS_AUTH) {

   398

				NetworkAddCommandQueue(cs, c);

   399

			}

   400

		}

   401

   402

		// Only the server gets the callback, because clients should not get them

   403

		c->callback = temp_callback;

   404

		if (_local_command_queue == NULL) {

   405

			_local_command_queue = c;

   406

		} else {

   407

			// Find last packet

   408

			CommandPacket *cp = _local_command_queue;

   409

			while (cp->next != NULL) cp = cp->next;

   410

			cp->next = c;

   411

		}

   412

   413

		return;

   414

	}

   415

   416

	// Clients send their command to the server and forget all about the packet

   417

	c->callback = temp_callback;

   418

	SEND_COMMAND(PACKET_CLIENT_COMMAND)(c);

   419

}

   420

   421

// Execute a DoCommand we received from the network

   422

void NetworkExecuteCommand(CommandPacket *cp)

   423

{

   424

	_current_player = cp->player;

   425

	memcpy(_decode_parameters, cp->dp, sizeof(cp->dp));

   426

	/* cp->callback is unsigned. so we don't need to do lower bounds checking. */

   427

	if (cp->callback > _callback_table_count) {

   428

		DEBUG(net,0) ("[NET] Received out-of-bounds callback! (%d)", cp->callback);

   429

		cp->callback = 0;

   430

	}

   431

	DoCommandP(cp->tile, cp->p1, cp->p2, _callback_table[cp->callback], cp->cmd | CMD_NETWORK_COMMAND);

   432

}

   433

   434

#endif /* ENABLE_NETWORK */