#define PSEUDO_HEAD_LEN 12 /* Pseudo head length */
#define ICMP_HEAD_LEN 4 /* ICMP head length */
#define WM_GETDATA WM_USER
typedef struct _PROTN2T
{
int proto ;
char *pprototext ;
}PROTN2T ;
/* The IP header */
typedef struct _IPHEADER {
unsigned char header_len:4; //位首部长度+4位IP版本号
unsigned char version:4;
unsigned char tos; // type of service
unsigned short total_len; // length of the packet
unsigned short ident; // unique identifier
unsigned short flags;
unsigned char ttl;
unsigned char proto; // protocol ( IP , TCP, UDP etc)
unsigned short checksum;
unsigned int sourceIP;
unsigned int destIP;