rubidium@5720: /* $Id$ */
rubidium@5720: 
celestar@6447: /**
celestar@6447:  * @file packet.cpp Basic functions to create, fill and read packets.
celestar@6447:  */
celestar@6447: 
rubidium@5720: #ifdef ENABLE_NETWORK
rubidium@5720: 
rubidium@5720: #include "../../stdafx.h"
rubidium@9723: #include "../../string_func.h"
rubidium@5720: 
rubidium@5720: #include "packet.h"
rubidium@5720: 
rubidium@6149: /**
rubidium@6149:  * Create a packet that is used to read from a network socket
rubidium@6149:  * @param cs the socket handler associated with the socket we are reading from
rubidium@6149:  */
rubidium@6149: Packet::Packet(NetworkSocketHandler *cs)
rubidium@6149: {
rubidium@6149: 	assert(cs != NULL);
rubidium@6149: 
rubidium@6149: 	this->cs   = cs;
rubidium@6149: 	this->next = NULL;
rubidium@6149: 	this->pos  = 0; // We start reading from here
rubidium@6149: 	this->size = 0;
rubidium@6149: }
rubidium@6149: 
rubidium@6149: /**
rubidium@6149:  * Creates a packet to send
rubidium@6149:  * @param type of the packet to send
rubidium@6149:  */
rubidium@6149: Packet::Packet(PacketType type)
rubidium@6149: {
rubidium@6149: 	this->cs                   = NULL;
rubidium@6149: 	this->next                 = NULL;
rubidium@6149: 
rubidium@6149: 	/* Skip the size so we can write that in before sending the packet */
rubidium@6149: 	this->pos                  = 0;
rubidium@6149: 	this->size                 = sizeof(PacketSize);
rubidium@6149: 	this->buffer[this->size++] = type;
rubidium@6149: }
rubidium@5720: 
rubidium@5720: /**
rubidium@5720:  * Create a packet for sending
rubidium@5720:  * @param type the of packet
rubidium@5720:  * @return the newly created packet
rubidium@5720:  */
rubidium@6149: Packet *NetworkSend_Init(PacketType type)
rubidium@5720: {
rubidium@6149: 	Packet *packet = new Packet(type);
rubidium@5720: 	/* An error is inplace here, because it simply means we ran out of memory. */
rubidium@5720: 	if (packet == NULL) error("Failed to allocate Packet");
rubidium@5720: 
rubidium@5720: 	return packet;
rubidium@5720: }
rubidium@5720: 
rubidium@5720: /**
rubidium@5720:  * Writes the packet size from the raw packet from packet->size
rubidium@5720:  */
rubidium@6573: void Packet::PrepareToSend()
rubidium@5720: {
rubidium@6149: 	assert(this->cs == NULL && this->next == NULL);
rubidium@6149: 
rubidium@6149: 	this->buffer[0] = GB(this->size, 0, 8);
rubidium@6149: 	this->buffer[1] = GB(this->size, 8, 8);
rubidium@6149: 
rubidium@6149: 	this->pos  = 0; // We start reading from here
rubidium@5720: }
rubidium@5720: 
rubidium@5720: /**
rubidium@5720:  * The next couple of functions make sure we can send
rubidium@5720:  *  uint8, uint16, uint32 and uint64 endian-safe
rubidium@5720:  *  over the network. The least significant bytes are
rubidium@5720:  *  sent first.
rubidium@5720:  *
rubidium@5720:  *  So 0x01234567 would be sent as 67 45 23 01.
rubidium@6169:  *
rubidium@6169:  * A bool is sent as a uint8 where zero means false
rubidium@6169:  *  and non-zero means true.
rubidium@5720:  */
rubidium@5720: 
rubidium@6169: void Packet::Send_bool(bool data)
rubidium@6169: {
rubidium@6169: 	this->Send_uint8(data ? 1 : 0);
rubidium@6169: }
rubidium@6169: 
rubidium@6151: void Packet::Send_uint8(uint8 data)
rubidium@5720: {
rubidium@6151: 	assert(this->size < sizeof(this->buffer) - sizeof(data));
rubidium@6151: 	this->buffer[this->size++] = data;
rubidium@5720: }
rubidium@5720: 
rubidium@6151: void Packet::Send_uint16(uint16 data)
rubidium@5720: {
rubidium@6151: 	assert(this->size < sizeof(this->buffer) - sizeof(data));
rubidium@6151: 	this->buffer[this->size++] = GB(data, 0, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 8, 8);
rubidium@5720: }
rubidium@5720: 
rubidium@6151: void Packet::Send_uint32(uint32 data)
rubidium@5720: {
rubidium@6151: 	assert(this->size < sizeof(this->buffer) - sizeof(data));
rubidium@6151: 	this->buffer[this->size++] = GB(data,  0, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data,  8, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 16, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 24, 8);
rubidium@6151: }
rubidium@6151: 
rubidium@6151: void Packet::Send_uint64(uint64 data)
rubidium@6151: {
rubidium@6151: 	assert(this->size < sizeof(this->buffer) - sizeof(data));
rubidium@6151: 	this->buffer[this->size++] = GB(data,  0, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data,  8, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 16, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 24, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 32, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 40, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 48, 8);
rubidium@6151: 	this->buffer[this->size++] = GB(data, 56, 8);
rubidium@5720: }
rubidium@5720: 
rubidium@5720: /**
rubidium@5720:  *  Sends a string over the network. It sends out
rubidium@5720:  *  the string + '\0'. No size-byte or something.
rubidium@6115:  * @param data   the string to send
rubidium@5720:  */
rubidium@6151: void Packet::Send_string(const char* data)
rubidium@5720: {
rubidium@5720: 	assert(data != NULL);
truelight@9718: 	/* The <= *is* valid due to the fact that we are comparing sizes and not the index. */
truelight@9718: 	assert(this->size + strlen(data) + 1 <= sizeof(this->buffer));
rubidium@6151: 	while ((this->buffer[this->size++] = *data++) != '\0') {}
rubidium@5720: }
rubidium@5720: 
rubidium@5720: 
rubidium@5720: /**
rubidium@5720:  * Receiving commands
rubidium@5720:  * Again, the next couple of functions are endian-safe
rubidium@6169:  *  see the comment before Send_bool for more info.
rubidium@5720:  */
rubidium@5720: 
rubidium@5720: 
rubidium@5720: /** Is it safe to read from the packet, i.e. didn't we run over the buffer ? */
rubidium@6151: bool Packet::CanReadFromPacket(uint bytes_to_read)
rubidium@5720: {
rubidium@5875: 	/* Don't allow reading from a quit client/client who send bad data */
rubidium@6151: 	if (this->cs->HasClientQuit()) return false;
rubidium@5720: 
rubidium@5720: 	/* Check if variable is within packet-size */
rubidium@6151: 	if (this->pos + bytes_to_read > this->size) {
rubidium@6151: 		this->cs->CloseConnection();
rubidium@5720: 		return false;
rubidium@5720: 	}
rubidium@5720: 
rubidium@5720: 	return true;
rubidium@5720: }
rubidium@5720: 
rubidium@5720: /**
rubidium@5720:  * Reads the packet size from the raw packet and stores it in the packet->size
rubidium@5720:  */
rubidium@6573: void Packet::ReadRawPacketSize()
rubidium@5720: {
rubidium@6149: 	assert(this->cs != NULL && this->next == NULL);
rubidium@6149: 	this->size  = (PacketSize)this->buffer[0];
rubidium@6149: 	this->size += (PacketSize)this->buffer[1] << 8;
rubidium@6149: }
rubidium@6149: 
rubidium@6149: /**
rubidium@6149:  * Prepares the packet so it can be read
rubidium@6149:  */
rubidium@6573: void Packet::PrepareToRead()
rubidium@6149: {
rubidium@6149: 	this->ReadRawPacketSize();
rubidium@6149: 
rubidium@6149: 	/* Put the position on the right place */
rubidium@6149: 	this->pos = sizeof(PacketSize);
rubidium@5720: }
rubidium@5720: 
rubidium@6573: bool Packet::Recv_bool()
rubidium@6169: {
rubidium@6169: 	return this->Recv_uint8() != 0;
rubidium@6169: }
rubidium@6169: 
rubidium@6573: uint8 Packet::Recv_uint8()
rubidium@5720: {
rubidium@5720: 	uint8 n;
rubidium@5720: 
rubidium@6151: 	if (!this->CanReadFromPacket(sizeof(n))) return 0;
rubidium@5720: 
rubidium@6151: 	n = this->buffer[this->pos++];
rubidium@5720: 	return n;
rubidium@5720: }
rubidium@5720: 
rubidium@6573: uint16 Packet::Recv_uint16()
rubidium@5720: {
rubidium@6151: 	uint16 n;
rubidium@5720: 
rubidium@6151: 	if (!this->CanReadFromPacket(sizeof(n))) return 0;
rubidium@5720: 
rubidium@6151: 	n  = (uint16)this->buffer[this->pos++];
rubidium@6151: 	n += (uint16)this->buffer[this->pos++] << 8;
rubidium@5720: 	return n;
rubidium@5720: }
rubidium@5720: 
rubidium@6573: uint32 Packet::Recv_uint32()
rubidium@6151: {
rubidium@6151: 	uint32 n;
rubidium@6151: 
rubidium@6151: 	if (!this->CanReadFromPacket(sizeof(n))) return 0;
rubidium@6151: 
rubidium@6151: 	n  = (uint32)this->buffer[this->pos++];
rubidium@6151: 	n += (uint32)this->buffer[this->pos++] << 8;
rubidium@6151: 	n += (uint32)this->buffer[this->pos++] << 16;
rubidium@6151: 	n += (uint32)this->buffer[this->pos++] << 24;
rubidium@6151: 	return n;
rubidium@6151: }
rubidium@6151: 
rubidium@6573: uint64 Packet::Recv_uint64()
rubidium@5720: {
rubidium@5720: 	uint64 n;
rubidium@5720: 
rubidium@6151: 	if (!this->CanReadFromPacket(sizeof(n))) return 0;
rubidium@5720: 
rubidium@6151: 	n  = (uint64)this->buffer[this->pos++];
rubidium@6151: 	n += (uint64)this->buffer[this->pos++] << 8;
rubidium@6151: 	n += (uint64)this->buffer[this->pos++] << 16;
rubidium@6151: 	n += (uint64)this->buffer[this->pos++] << 24;
rubidium@6151: 	n += (uint64)this->buffer[this->pos++] << 32;
rubidium@6151: 	n += (uint64)this->buffer[this->pos++] << 40;
rubidium@6151: 	n += (uint64)this->buffer[this->pos++] << 48;
rubidium@6151: 	n += (uint64)this->buffer[this->pos++] << 56;
rubidium@5720: 	return n;
rubidium@5720: }
rubidium@5720: 
rubidium@5720: /** Reads a string till it finds a '\0' in the stream */
rubidium@6151: void Packet::Recv_string(char *buffer, size_t size)
rubidium@5720: {
rubidium@5720: 	PacketSize pos;
rubidium@5720: 	char *bufp = buffer;
rubidium@5720: 
rubidium@5720: 	/* Don't allow reading from a closed socket */
rubidium@5875: 	if (cs->HasClientQuit()) return;
rubidium@5720: 
rubidium@6151: 	pos = this->pos;
rubidium@6151: 	while (--size > 0 && pos < this->size && (*buffer++ = this->buffer[pos++]) != '\0') {}
rubidium@5720: 
rubidium@6151: 	if (size == 0 || pos == this->size) {
rubidium@5720: 		*buffer = '\0';
rubidium@5720: 		/* If size was sooner to zero then the string in the stream
rubidium@5720: 		 *  skip till the \0, so than packet can be read out correctly for the rest */
rubidium@6151: 		while (pos < this->size && this->buffer[pos] != '\0') pos++;
rubidium@5720: 		pos++;
rubidium@5720: 	}
rubidium@6151: 	this->pos = pos;
rubidium@5720: 
rubidium@5720: 	str_validate(bufp);
rubidium@5720: }
rubidium@5720: 
rubidium@5720: #endif /* ENABLE_NETWORK */