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

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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.

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

    20

    21

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

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

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

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	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

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//

    35

    36

void NetworkSend_uint8(Packet *packet, uint8 data)

    37

{

    38

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

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

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}

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    42

void NetworkSend_uint16(Packet *packet, uint16 data)

    43

{

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

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

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

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}

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    49

void NetworkSend_uint32(Packet *packet, uint32 data)

    50

{

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

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

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

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

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	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));

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

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

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

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

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

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

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

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

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}

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    71

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

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

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

    74

{

    75

	assert(data != NULL);

    76

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

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

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}

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    80

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

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

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

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assert_compile(sizeof(PacketSize) == 2);

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    85

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

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//  as soon as possible

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

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//   OS-network-buffer is full)

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void NetworkSend_Packet(Packet *packet, NetworkClientState *cs)

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{

    91

	Packet *p;

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	assert(packet != NULL);

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    94

	packet->pos = 0;

    95

	packet->next = NULL;

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    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

	}

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}

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   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.

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

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// For servers: close connection and that is it

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static 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:

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

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

   137

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

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//   3) sending took too long

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bool NetworkSend_Packets(NetworkClientState *cs)

   140

{

   141

	ssize_t res;

   142

	Packet *p;

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   144

	// We can not write to this socket!!

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	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) {

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				// Something went wrong.. close client!

   155

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

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				CloseConnection(cs);

   157

				return false;

   158

			}

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			return true;

   160

		}

   161

		if (res == 0) {

   162

			// Client/server has left us :(

   163

			CloseConnection(cs);

   164

			return false;

   165

		}

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   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

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			return true;

   177

	}

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   179

	return true;

   180

}

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   182

   183

// Receiving commands

   184

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

   185

//  see the comment around NetworkSend_uint8 for more info.

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uint8 NetworkRecv_uint8(NetworkClientState *cs, Packet *packet)

   187

{

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	/* Don't allow reading from a closed socket */

   189

	if (cs->quited)

   190

		return 0;

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   192

	/* Check if variable is within packet-size */

   193

	if (packet->pos + 1 > packet->size) {

   194

		CloseConnection(cs);

   195

		return 0;

   196

	}

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   198

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

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}

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   201

uint16 NetworkRecv_uint16(NetworkClientState *cs, Packet *packet)

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{

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	uint16 n;

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	/* Don't allow reading from a closed socket */

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	if (cs->quited)

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		return 0;

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   209

	/* Check if variable is within packet-size */

   210

	if (packet->pos + 2 > packet->size) {

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		CloseConnection(cs);

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		return 0;

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	}

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   215

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

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

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	return n;

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}

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uint32 NetworkRecv_uint32(NetworkClientState *cs, Packet *packet)

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{

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	uint32 n;

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	/* Don't allow reading from a closed socket */

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	if (cs->quited)

   226

		return 0;

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   228

	/* Check if variable is within packet-size */

   229

	if (packet->pos + 4 > packet->size) {

   230

		CloseConnection(cs);

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		return 0;

   232

	}

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   234

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

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

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

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

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	return n;

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}

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   241

uint64 NetworkRecv_uint64(NetworkClientState *cs, Packet *packet)

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{

   243

	uint64 n;

   244

   245

	/* Don't allow reading from a closed socket */

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	if (cs->quited)

   247

		return 0;

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   249

	/* Check if variable is within packet-size */

   250

	if (packet->pos + 8 > packet->size) {

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		CloseConnection(cs);

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		return 0;

   253

	}

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   255

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

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

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

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

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

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

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

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

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	return n;

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}

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   266

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

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

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{

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	int pos;

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	/* Don't allow reading from a closed socket */

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	if (cs->quited)

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		return;

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   275

	pos = p->pos;

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

   277

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

   278

	{

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		*buffer = '\0';

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

   281

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

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

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		++pos;

   284

	}

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	p->pos = pos;

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}

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   288

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

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

   290

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

   291

assert_compile(sizeof(PacketSize) == 2);

   292

   293

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

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{

   295

	ssize_t res;

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	Packet *p;

   297

   298

	*status = NETWORK_RECV_STATUS_OKAY;

   299

   300

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

   301

   302

	if (cs->packet_recv == NULL) {

   303

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

   304

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

   305

		// Set pos to zero!

   306

		cs->packet_recv->pos = 0;

   307

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

   308

	}

   309

   310

	p = cs->packet_recv;

   311

   312

	// Read packet size

   313

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

   314

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

   315

			// Read the size of the packet

   316

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

   317

			if (res == -1) {

   318

				int err = GET_LAST_ERROR();

   319

				if (err != EWOULDBLOCK) {

   320

					// Something went wrong..

   321

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

   322

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

   323

					*status = CloseConnection(cs);

   324

					return NULL;

   325

				}

   326

				// Connection would block, so stop for now

   327

				return NULL;

   328

			}

   329

			if (res == 0) {

   330

				// Client/server has left us :(

   331

				*status = CloseConnection(cs);

   332

				return NULL;

   333

			}

   334

			p->pos += res;

   335

		}

   336

   337

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

   338

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

   339

   340

		if (p->size > SEND_MTU) {

   341

			*status = CloseConnection(cs);

   342

			return NULL;

   343

		}

   344

	}

   345

   346

	// Read rest of packet

   347

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

   348

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

   349

		if (res == -1) {

   350

			int err = GET_LAST_ERROR();

   351

			if (err != EWOULDBLOCK) {

   352

				// Something went wrong..

   353

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

   354

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

   355

				*status = CloseConnection(cs);

   356

				return NULL;

   357

			}

   358

			// Connection would block

   359

			return NULL;

   360

		}

   361

		if (res == 0) {

   362

			// Client/server has left us :(

   363

			*status = CloseConnection(cs);

   364

			return NULL;

   365

		}

   366

   367

		p->pos += res;

   368

	}

   369

   370

	// We have a complete packet, return it!

   371

	p->pos = 2;

   372

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

   373

   374

	// Prepare for receiving a new packet

   375

	cs->packet_recv = NULL;

   376

   377

	return p;

   378

}

   379

   380

// Add a command to the local command queue

   381

void NetworkAddCommandQueue(NetworkClientState *cs, CommandPacket *cp)

   382

{

   383

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

   384

   385

	*new_cp = *cp;

   386

   387

	if (cs->command_queue == NULL)

   388

		cs->command_queue = new_cp;

   389

	else {

   390

		CommandPacket *c = cs->command_queue;

   391

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

   392

		c->next = new_cp;

   393

	}

   394

}

   395

   396

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

   397

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

   398

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

   399

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

   400

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

   401

   402

// Prepare a DoCommand to be send over the network

   403

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

   404

{

   405

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

   406

	byte temp_callback;

   407

   408

	c->player = _local_player;

   409

	c->next = NULL;

   410

	c->tile = tile;

   411

	c->p1 = p1;

   412

	c->p2 = p2;

   413

	c->cmd = cmd;

   414

	c->callback = 0;

   415

   416

	temp_callback = 0;

   417

   418

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

   419

		temp_callback++;

   420

	if (temp_callback == _callback_table_count) {

   421

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

   422

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

   423

	}

   424

   425

	if (_network_server) {

   426

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

   427

		c->frame = _frame_counter_max + 1;

   428

	} else {

   429

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

   430

	}

   431

   432

	// Copy the _decode_parameters to dp

   433

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

   434

   435

	if (_network_server) {

   436

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

   437

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

   438

		//   client on the server can do everything 1 tick faster than others.

   439

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

   440

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

   441

		NetworkClientState *cs;

   442

   443

		// And we queue it for delivery to the clients

   444

		FOR_ALL_CLIENTS(cs) {

   445

			if (cs->status > STATUS_AUTH) {

   446

				NetworkAddCommandQueue(cs, c);

   447

			}

   448

		}

   449

   450

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

   451

		c->callback = temp_callback;

   452

		if (_local_command_queue == NULL) {

   453

			_local_command_queue = c;

   454

		} else {

   455

			// Find last packet

   456

			CommandPacket *cp = _local_command_queue;

   457

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

   458

			cp->next = c;

   459

		}

   460

   461

		return;

   462

	}

   463

   464

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

   465

	c->callback = temp_callback;

   466

	SEND_COMMAND(PACKET_CLIENT_COMMAND)(c);

   467

}

   468

   469

// Execute a DoCommand we received from the network

   470

void NetworkExecuteCommand(CommandPacket *cp)

   471

{

   472

	_current_player = cp->player;

   473

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

   474

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

   475

	if (cp->callback > _callback_table_count) {

   476

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

   477

		cp->callback = 0;

   478

	}

   479

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

   480

}

   481

   482

#endif /* ENABLE_NETWORK */