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/* This file is part of the Spring engine (GPL v2 or later), see LICENSE.html */
#include "ProtocolDef.h"
#include <string.h>
#include "System/SpringFormat.h"
#include "Exception.h"
namespace netcode {
ProtocolDef* ProtocolDef::GetInstance()
{
static ProtocolDef instance;
return &instance;
}
ProtocolDef::ProtocolDef()
{
memset(msg, '\0', sizeof(MsgType) * 256);
}
void ProtocolDef::AddType(const unsigned char id, const int msgLength)
{
msg[id].length = msgLength;
}
int ProtocolDef::PacketLength(const unsigned char* const buf, const unsigned bufLength) const
{
if (bufLength == 0) {
return 0;
}
unsigned char msgid = buf[0];
int len = msg[msgid].length;
if (len > 0) {
return len;
}
if (len == 0) {
return -2;
}
if (len == -1) {
if (bufLength < 2)
return 0;
return (buf[1] >= 2) ? buf[1] : -1;
}
if (len == -2) {
if (bufLength < 3) {
return 0;
}
unsigned short slen = *((unsigned short*)(buf + 1));
return (slen >= 3) ? slen : -1;
}
throw network_error(spring::format("Invalid Message Length: %u", (unsigned int)msgid ));
}
bool ProtocolDef::IsValidLength(const int pktLength, const unsigned bufLength) const
{
return (pktLength > 0) && (bufLength >= (unsigned)pktLength);
}
bool ProtocolDef::IsValidPacket(const unsigned char* const buf, const unsigned bufLength) const
{
return IsValidLength(PacketLength(buf, bufLength), bufLength);
}
} // namespace netcode
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