packet.cpp

一些有C制作Fire Wall的代码

#include "packet.h"

//顺序对换的函数
//

USHORT
ntohs(
	IN	USHORT		netshort
)
{
	CHAR hostshort[4];
	PCHAR pnetshort = (PCHAR)&netshort;
	hostshort[0] = pnetshort[1];
	hostshort[1] = pnetshort[0];
	return *(USHORT *)hostshort;
}

ULONG
ntohl(
	IN	ULONG		netlong
)
{
	CHAR hostlong[4];
	PCHAR pnetlong = (PCHAR)&netlong;
	hostlong[0] = pnetlong[3];
	hostlong[1] = pnetlong[2];
	hostlong[2] = pnetlong[1];
	hostlong[3] = pnetlong[0];
	return *(ULONG*)hostlong;
}