7 * Structure of an internet header, naked of options.
9 * We declare ip_len and ip_off to be short, rather than u_short
10 * pragmatically since otherwise unsigned comparisons can result
11 * against negative integers quite easily, and fail in subtle ways.
16 #if defined(NO_CHAR_BITFIELDS)
17 u_char ip_hl_v; /* bug in GCC for mips means the bitfield stuff will sometimes break - so we use a char for both and get round it with macro's instead... */
19 #if BYTE_ORDER == LITTLE_ENDIAN
20 unsigned ip_hl:4, /* header length */
21 ip_v :4; /* version */
22 #elif BYTE_ORDER == BIG_ENDIAN
23 unsigned ip_v :4, /* version */
24 ip_hl:4; /* header length */
26 COMPLAIN - NO BYTE ORDER SELECTED!
29 u_char ip_tos; /* type of service */
30 u_short ip_len; /* total length */
31 u_short ip_id; /* identification */
32 u_short ip_off; /* fragment offset field */
33 #define IP_DF 0x4000 /* dont fragment flag */
34 #define IP_MF 0x2000 /* more fragments flag */
35 #define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
36 u_char ip_ttl; /* time to live */
37 u_char ip_p; /* protocol */
38 u_short ip_sum; /* checksum */
39 struct in_addr ip_src,ip_dst; /* source and dest address */
43 typedef u32_t tcp_seq;
47 * Per RFC 793, September, 1981.
52 u_short th_sport; /* source port */
53 u_short th_dport; /* destination port */
54 tcp_seq th_seq; /* sequence number */
55 tcp_seq th_ack; /* acknowledgement number */
56 #if defined(NO_CHAR_BITFIELDS)
59 #if BYTE_ORDER == LITTLE_ENDIAN
60 unsigned th_x2 :4, /* (unused) */
61 th_off:4; /* data offset */
63 #if BYTE_ORDER == BIG_ENDIAN
64 unsigned th_off:4, /* data offset */
65 th_x2 :4; /* (unused) */
69 u_short th_win; /* window */
70 u_short th_sum; /* checksum */
71 u_short th_urp; /* urgent pointer */
75 #endif /* VJBSDHDR_H */