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