struct ether_header
{
u_int8_t ether_dhost[ETH_ALEN]; /* destination eth addr */
u_int8_t ether_shost[ETH_ALEN]; /* source ether addr */
u_int16_t ether_type; /* packet type ID field */
} __attribute__ ((__packed__));
------------------------------------------------------------------------------------
struct udphdr {
__u16 source;
__u16 dest;
__u16 len;
__u16 check;
};
**********************************
#ifdef __FAVOR_BSD
struct udphdr {
u_int16_t uh_sport; /* source port */
u_int16_t uh_dport; /* destination port */
u_int16_t uh_ulen; /* udp length */
u_int16_t uh_sum; /* udp checksum */
};
#else
struct udphdr {
u_int16_t source;
u_int16_t dest;
u_int16_t len;
u_int16_t check;
};
#endif
--------------------------------------------------------------------------------------------------------
# ifdef __FAVOR_BSD
typedef u_int32_t tcp_seq;
/*
* TCP header.
* Per RFC 793, September, 1981.
*/
struct tcphdr
{
u_int16_t th_sport; /* source port */
u_int16_t th_dport; /* destination port */
tcp_seq th_seq; /* sequence number */
tcp_seq th_ack; /* acknowledgement number */
# if __BYTE_ORDER == __LITTLE_ENDIAN
u_int8_t th_x2:4; /* (unused) */
u_int8_t th_off:4; /* data offset */
# endif
# if __BYTE_ORDER == __BIG_ENDIAN
u_int8_t th_off:4; /* data offset */
u_int8_t th_x2:4; /* (unused) */
# endif
u_int8_t th_flags;
# define TH_FIN 0x01
# define TH_SYN 0x02
# define TH_RST 0x04
# define TH_PUSH 0x08
# define TH_ACK 0x10
# define TH_URG 0x20
u_int16_t th_win; /* window */
u_int16_t th_sum; /* checksum */
u_int16_t th_urp; /* urgent pointer */
};
# else /* !__FAVOR_BSD */
struct tcphdr
{
u_int16_t source;
u_int16_t dest;
u_int32_t seq;
u_int32_t ack_seq;
# if __BYTE_ORDER == __LITTLE_ENDIAN
u_int16_t res1:4;
u_int16_t doff:4;
u_int16_t fin:1;
u_int16_t syn:1;
u_int16_t rst:1;
u_int16_t psh:1;
u_int16_t ack:1;
u_int16_t urg:1;
u_int16_t res2:2;
# elif __BYTE_ORDER == __BIG_ENDIAN
u_int16_t doff:4;
u_int16_t res1:4;
u_int16_t res2:2;
u_int16_t urg:1;
u_int16_t ack:1;
u_int16_t psh:1;
u_int16_t rst:1;
u_int16_t syn:1;
u_int16_t fin:1;
# else
# error "Adjust your defines"
# endif
u_int16_t window;
u_int16_t check;
u_int16_t urg_ptr;
};
# endif /* __FAVOR_BSD */
*****************************************************
struct tcphdr {
__u16 source;
__u16 dest;
__u32 seq;
__u32 ack_seq;
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u16 res1:4,
doff:4,
fin:1,
syn:1,
rst:1,
psh:1,
ack:1,
urg:1,
ece:1,
cwr:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u16 doff:4,
res1:4,
cwr:1,
ece:1,
urg:1,
ack:1,
psh:1,
rst:1,
syn:1,
fin:1;
#else
#error "Adjust your defines"
#endif
__u16 window;
__u16 check;
__u16 urg_ptr;
};
---------------------------------------------------------------------------------------------
struct iphdr {
#if defined(__LITTLE_ENDIAN)
__u8 ihl:4,
version:4;
#elif defined (__BIG_ENDIAN)
__u8 version:4,
ihl:4;
#endif
__u8 tos;
__u16 tot_len;
__u16 id;
__u16 frag_off;
__u8 ttl;
__u8 protocol;
__u16 check;
__u32 saddr;
__u32 daddr;
/*The options start here. */
};
