pcap-test.h

#include <pcap.h>
#include <stdbool.h>
#include <stdio.h>

#define ETHER_ADDR_LEN 6

struct libnet_ether_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 */
};

struct libnet_ipv4_hdr
{
#if (LIBNET_LIL_ENDIAN)
    u_int8_t ip_hl:4,      /* header length */
           ip_v:4;         /* version */
#endif
#if (LIBNET_BIG_ENDIAN)
    u_int8_t ip_v:4,       /* version */
           ip_hl:4;        /* header length */
#endif
    u_int8_t ip_tos;       /* type of service */
#ifndef IPTOS_LOWDELAY
#define IPTOS_LOWDELAY      0x10
#endif
#ifndef IPTOS_THROUGHPUT
#define IPTOS_THROUGHPUT    0x08
#endif
#ifndef IPTOS_RELIABILITY
#define IPTOS_RELIABILITY   0x04
#endif
#ifndef IPTOS_LOWCOST
#define IPTOS_LOWCOST       0x02
#endif
    u_int16_t ip_len;         /* total length */
    u_int16_t ip_id;          /* identification */
    u_int16_t ip_off;
#ifndef IP_RF
#define IP_RF 0x8000        /* reserved fragment flag */
#endif
#ifndef IP_DF
#define IP_DF 0x4000        /* dont fragment flag */
#endif
#ifndef IP_MF
#define IP_MF 0x2000        /* more fragments flag */
#endif
#ifndef IP_OFFMASK
#define IP_OFFMASK 0x1fff   /* mask for fragmenting bits */
#endif
    u_int8_t ip_ttl;          /* time to live */
    u_int8_t ip_p;            /* protocol */
    u_int16_t ip_sum;         /* checksum */
    struct in_addr ip_src, ip_dst; /* source and dest address */
};

struct libnet_tcp_hdr
{
    u_int16_t th_sport;       /* source port */
    u_int16_t th_dport;       /* destination port */
    u_int32_t th_seq;          /* sequence number */
    u_int32_t th_ack;          /* acknowledgement number */
    u_int8_t th_x2:4,         /* (unused) */
           th_off:4;        /* data offset */
    u_int8_t  th_flags;       /* control flags */
#ifndef TH_FIN
#define TH_FIN    0x01      /* finished send data */
#endif
#ifndef TH_SYN
#define TH_SYN    0x02      /* synchronize sequence numbers */
#endif
#ifndef TH_RST
#define TH_RST    0x04      /* reset the connection */
#endif
#ifndef TH_PUSH
#define TH_PUSH   0x08      /* push data to the app layer */
#endif
#ifndef TH_ACK
#define TH_ACK    0x10      /* acknowledge */
#endif
#ifndef TH_URG
#define TH_URG    0x20      /* urgent! */
#endif
#ifndef TH_ECE
#define TH_ECE    0x40
#endif
#ifndef TH_CWR
#define TH_CWR    0x80
#endif
    u_int16_t th_win;         /* window */
    u_int16_t th_sum;         /* checksum */
    u_int16_t th_urp;         /* urgent pointer */
};