typedef struct eth_hdr
{
u8 d_mac[6];
u8 s_mac[6];
u16 type;
}ETH_HDR;
typedef struct arp_hdr
{
ETH_HDR ethhdr;
u16 hwtype;
u16 protocol;
u8 hwlen;
u8 protolen;
u16 opcode;
u8 smac[6];
u8 sipaddr[4];
u8 dmac[6];
u8 dipaddr[4];
}ARP_HDR;
typedef struct ip_hdr
{
ETH_HDR ethhdr;
u8 vhl;
u8 tos;
u16 len;
u16 ipid;
u16 ipoffset;
u8 ttl;
u8 proto;
u16 ipchksum;
u8 srcipaddr[4];
u8 destipaddr[4];
}IP_HDR;
typedef struct udp_hdr
{
IP_HDR iphdr;
u16 sport;
u16 dport;
u16 len;
u16 udpchksum;
}UDP_HDR;