celestar@5642: /* $Id$ */
celestar@5642: 
celestar@5642: #ifdef ENABLE_NETWORK
celestar@5642: 
celestar@5642: #include "../../stdafx.h"
celestar@5642: #include "../../macros.h"
celestar@5642: #include "../../string.h"
celestar@5642: 
celestar@5642: #include "packet.h"
celestar@5642: 
celestar@5642: /**
celestar@5642:  * @file packet.h Basic functions to create, fill and read packets.
celestar@5642:  */
celestar@5642: 
celestar@5642: 
celestar@5642: /* Do not want to include functions.h and all required headers */
celestar@5642: extern void NORETURN CDECL error(const char *str, ...);
celestar@5642: 
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Create a packet for sending
celestar@5642:  * @param type the of packet
celestar@5642:  * @return the newly created packet
celestar@5642:  */
celestar@5648: Packet *NetworkSend_Init(const PacketType type)
celestar@5642: {
celestar@5642: 	Packet *packet = malloc(sizeof(Packet));
celestar@5642: 	/* An error is inplace here, because it simply means we ran out of memory. */
celestar@5642: 	if (packet == NULL) error("Failed to allocate Packet");
celestar@5642: 
celestar@5642: 	/* Skip the size so we can write that in before sending the packet */
celestar@5642: 	packet->size = sizeof(packet->size);
celestar@5642: 	packet->buffer[packet->size++] = type;
celestar@5642: 	packet->pos = 0;
celestar@5642: 
celestar@5642: 	return packet;
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Writes the packet size from the raw packet from packet->size
celestar@5642:  * @param packet the packet to write the size of
celestar@5642:  */
celestar@5642: void NetworkSend_FillPacketSize(Packet *packet)
celestar@5642: {
celestar@5642: 	packet->buffer[0] = GB(packet->size, 0, 8);
celestar@5642: 	packet->buffer[1] = GB(packet->size, 8, 8);
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  * The next couple of functions make sure we can send
celestar@5642:  *  uint8, uint16, uint32 and uint64 endian-safe
celestar@5642:  *  over the network. The least significant bytes are
celestar@5642:  *  sent first.
celestar@5642:  *
celestar@5642:  *  So 0x01234567 would be sent as 67 45 23 01.
celestar@5642:  */
celestar@5642: 
celestar@5642: void NetworkSend_uint8(Packet *packet, uint8 data)
celestar@5642: {
celestar@5642: 	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
celestar@5642: 	packet->buffer[packet->size++] = data;
celestar@5642: }
celestar@5642: 
celestar@5642: void NetworkSend_uint16(Packet *packet, uint16 data)
celestar@5642: {
celestar@5642: 	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 0, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 8, 8);
celestar@5642: }
celestar@5642: 
celestar@5642: void NetworkSend_uint32(Packet *packet, uint32 data)
celestar@5642: {
celestar@5642: 	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
celestar@5642: 	packet->buffer[packet->size++] = GB(data,  0, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data,  8, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 16, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 24, 8);
celestar@5642: }
celestar@5642: 
celestar@5642: void NetworkSend_uint64(Packet *packet, uint64 data)
celestar@5642: {
celestar@5642: 	assert(packet->size < sizeof(packet->buffer) - sizeof(data));
celestar@5642: 	packet->buffer[packet->size++] = GB(data,  0, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data,  8, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 16, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 24, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 32, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 40, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 48, 8);
celestar@5642: 	packet->buffer[packet->size++] = GB(data, 56, 8);
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  *  Sends a string over the network. It sends out
celestar@5642:  *  the string + '\0'. No size-byte or something.
celestar@5642:  */
celestar@5642: void NetworkSend_string(Packet *packet, const char* data)
celestar@5642: {
celestar@5642: 	assert(data != NULL);
celestar@5642: 	assert(packet->size < sizeof(packet->buffer) - strlen(data) - 1);
celestar@5642: 	while ((packet->buffer[packet->size++] = *data++) != '\0') {}
celestar@5642: }
celestar@5642: 
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Receiving commands
celestar@5642:  * Again, the next couple of functions are endian-safe
celestar@5642:  *  see the comment before NetworkSend_uint8 for more info.
celestar@5642:  */
celestar@5642: 
celestar@5642: 
celestar@5642: extern uint CloseConnection(NetworkClientState *cs);
celestar@5642: 
celestar@5642: /** Is it safe to read from the packet, i.e. didn't we run over the buffer ? */
celestar@5648: static inline bool CanReadFromPacket(NetworkClientState *cs, const Packet *packet, const uint bytes_to_read)
celestar@5642: {
celestar@5642: 	/* Don't allow reading from a closed socket */
celestar@5642: 	if (HasClientQuit(cs)) return false;
celestar@5642: 
celestar@5642: 	/* Check if variable is within packet-size */
celestar@5642: 	if (packet->pos + bytes_to_read > packet->size) {
celestar@5642: 		CloseConnection(cs);
celestar@5642: 		return false;
celestar@5642: 	}
celestar@5642: 
celestar@5642: 	return true;
celestar@5642: }
celestar@5642: 
celestar@5642: /**
celestar@5642:  * Reads the packet size from the raw packet and stores it in the packet->size
celestar@5642:  * @param packet the packet to read the size of
celestar@5642:  */
celestar@5642: void NetworkRecv_ReadPacketSize(Packet *packet)
celestar@5642: {
celestar@5642: 	packet->size  = (uint16)packet->buffer[0];
celestar@5642: 	packet->size += (uint16)packet->buffer[1] << 8;
celestar@5642: }
celestar@5642: 
celestar@5642: uint8 NetworkRecv_uint8(NetworkClientState *cs, Packet *packet)
celestar@5642: {
celestar@5642: 	uint8 n;
celestar@5642: 
celestar@5642: 	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
celestar@5642: 
celestar@5642: 	n = packet->buffer[packet->pos++];
celestar@5642: 	return n;
celestar@5642: }
celestar@5642: 
celestar@5642: uint16 NetworkRecv_uint16(NetworkClientState *cs, Packet *packet)
celestar@5642: {
celestar@5642: 	uint16 n;
celestar@5642: 
celestar@5642: 	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
celestar@5642: 
celestar@5642: 	n  = (uint16)packet->buffer[packet->pos++];
celestar@5642: 	n += (uint16)packet->buffer[packet->pos++] << 8;
celestar@5642: 	return n;
celestar@5642: }
celestar@5642: 
celestar@5642: uint32 NetworkRecv_uint32(NetworkClientState *cs, Packet *packet)
celestar@5642: {
celestar@5642: 	uint32 n;
celestar@5642: 
celestar@5642: 	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
celestar@5642: 
celestar@5642: 	n  = (uint32)packet->buffer[packet->pos++];
celestar@5642: 	n += (uint32)packet->buffer[packet->pos++] << 8;
celestar@5642: 	n += (uint32)packet->buffer[packet->pos++] << 16;
celestar@5642: 	n += (uint32)packet->buffer[packet->pos++] << 24;
celestar@5642: 	return n;
celestar@5642: }
celestar@5642: 
celestar@5642: uint64 NetworkRecv_uint64(NetworkClientState *cs, Packet *packet)
celestar@5642: {
celestar@5642: 	uint64 n;
celestar@5642: 
celestar@5642: 	if (!CanReadFromPacket(cs, packet, sizeof(n))) return 0;
celestar@5642: 
celestar@5642: 	n  = (uint64)packet->buffer[packet->pos++];
celestar@5642: 	n += (uint64)packet->buffer[packet->pos++] << 8;
celestar@5642: 	n += (uint64)packet->buffer[packet->pos++] << 16;
celestar@5642: 	n += (uint64)packet->buffer[packet->pos++] << 24;
celestar@5642: 	n += (uint64)packet->buffer[packet->pos++] << 32;
celestar@5642: 	n += (uint64)packet->buffer[packet->pos++] << 40;
celestar@5642: 	n += (uint64)packet->buffer[packet->pos++] << 48;
celestar@5642: 	n += (uint64)packet->buffer[packet->pos++] << 56;
celestar@5642: 	return n;
celestar@5642: }
celestar@5642: 
celestar@5642: /** Reads a string till it finds a '\0' in the stream */
celestar@5642: void NetworkRecv_string(NetworkClientState *cs, Packet *p, char *buffer, size_t size)
celestar@5642: {
celestar@5642: 	PacketSize pos;
celestar@5642: 	char *bufp = buffer;
celestar@5642: 
celestar@5642: 	/* Don't allow reading from a closed socket */
celestar@5642: 	if (HasClientQuit(cs)) return;
celestar@5642: 
celestar@5642: 	pos = p->pos;
celestar@5642: 	while (--size > 0 && pos < p->size && (*buffer++ = p->buffer[pos++]) != '\0') {}
celestar@5642: 
celestar@5642: 	if (size == 0 || pos == p->size) {
celestar@5642: 		*buffer = '\0';
celestar@5642: 		/* If size was sooner to zero then the string in the stream
celestar@5642: 		 *  skip till the \0, so than packet can be read out correctly for the rest */
celestar@5642: 		while (pos < p->size && p->buffer[pos] != '\0') pos++;
celestar@5642: 		pos++;
celestar@5642: 	}
celestar@5642: 	p->pos = pos;
celestar@5642: 
celestar@5642: 	str_validate(bufp);
celestar@5642: }
celestar@5642: 
celestar@5642: #endif /* ENABLE_NETWORK */