header.h

#include <sys/types.h>
#include <netinet/in.h>

#define IP_ADDR_LEN      4
#define ETHER_ADDR_LEN   6
#define IP_ADDR_STR_SIZE 16

/*
 *  Ethernet II header
 *  Static header size: 14 bytes
 */
struct libnet_ethernet_hdr
{
    u_int8_t  ether_dhost[ETHER_ADDR_LEN];/* destination ethernet address */
    u_int8_t  ether_shost[ETHER_ADDR_LEN];/* source ethernet address */
    u_int16_t ether_type;                 /* protocol */
};


#define ETHERTYPE_IP 0x0800
#define ETHERTYPE_ARP 0x0806


#define ETH_H         14
#define ARP_H         28
#define ETH_ARP_H     42
#define PAD_H         18 // in arp packet
#define ETH_ARP_PAD_H 60

#define MEMSET_BROADCAST -1
#define MEMSET_NULL       0

#define SEC 1000000

struct libnet_arp_hdr
{
    u_int16_t ar_hrd;         /* format of hardware address */
#define ARPHRD_NETROM   0   /* from KA9Q: NET/ROM pseudo */
#define ARPHRD_ETHER    1   /* Ethernet 10Mbps */
#define ARPHRD_EETHER   2   /* Experimental Ethernet */
#define ARPHRD_AX25     3   /* AX.25 Level 2 */
#define ARPHRD_PRONET   4   /* PROnet token ring */
#define ARPHRD_CHAOS    5   /* Chaosnet */
#define ARPHRD_IEEE802  6   /* IEEE 802.2 Ethernet/TR/TB */
#define ARPHRD_ARCNET   7   /* ARCnet */
#define ARPHRD_APPLETLK 8   /* APPLEtalk */
#define ARPHRD_LANSTAR  9   /* Lanstar */
#define ARPHRD_DLCI     15  /* Frame Relay DLCI */
#define ARPHRD_ATM      19  /* ATM */
#define ARPHRD_METRICOM 23  /* Metricom STRIP (new IANA id) */
#define ARPHRD_IPSEC    31  /* IPsec tunnel */
    u_int16_t ar_pro;         /* format of protocol address */
    u_int8_t  ar_hln;         /* length of hardware address */
    u_int8_t  ar_pln;         /* length of protocol addres */
    u_int16_t ar_op;          /* operation type */
#define ARPOP_REQUEST    1  /* req to resolve address */
#define ARPOP_REPLY      2  /* resp to previous request */
#define ARPOP_REVREQUEST 3  /* req protocol address given hardware */
#define ARPOP_REVREPLY   4  /* resp giving protocol address */
#define ARPOP_INVREQUEST 8  /* req to identify peer */
#define ARPOP_INVREPLY   9  /* resp identifying peer */
                            /* address information allocated dynamically */

#define IP_ADDR_LEN 4

    u_int8_t source_host[ETHER_ADDR_LEN];
    u_int8_t source_ip[IP_ADDR_LEN];
    u_int8_t desti_host[ETHER_ADDR_LEN];
    u_int8_t desti_ip[IP_ADDR_LEN];

};