nf_conntrack_tcp.h revision a09113c2c8ec59a5cc228efa5869aade2b8f13f7 
1#ifndef _NF_CONNTRACK_TCP_H
2#define _NF_CONNTRACK_TCP_H
3/* TCP tracking. */
4
5/* This is exposed to userspace (ctnetlink) */
6enum tcp_conntrack {
7	TCP_CONNTRACK_NONE,
8	TCP_CONNTRACK_SYN_SENT,
9	TCP_CONNTRACK_SYN_RECV,
10	TCP_CONNTRACK_ESTABLISHED,
11	TCP_CONNTRACK_FIN_WAIT,
12	TCP_CONNTRACK_CLOSE_WAIT,
13	TCP_CONNTRACK_LAST_ACK,
14	TCP_CONNTRACK_TIME_WAIT,
15	TCP_CONNTRACK_CLOSE,
16	TCP_CONNTRACK_LISTEN,
17	TCP_CONNTRACK_MAX,
18	TCP_CONNTRACK_IGNORE
19};
20
21/* Window scaling is advertised by the sender */
22#define IP_CT_TCP_FLAG_WINDOW_SCALE		0x01
23
24/* SACK is permitted by the sender */
25#define IP_CT_TCP_FLAG_SACK_PERM		0x02
26
27/* This sender sent FIN first */
28#define IP_CT_TCP_FLAG_CLOSE_INIT		0x04
29
30/* Be liberal in window checking */
31#define IP_CT_TCP_FLAG_BE_LIBERAL		0x08
32
33#ifdef __KERNEL__
34
35struct ip_ct_tcp_state {
36	u_int32_t	td_end;		/* max of seq + len */
37	u_int32_t	td_maxend;	/* max of ack + max(win, 1) */
38	u_int32_t	td_maxwin;	/* max(win) */
39	u_int8_t	td_scale;	/* window scale factor */
40	u_int8_t	flags;		/* per direction options */
41};
42
43struct ip_ct_tcp
44{
45	struct ip_ct_tcp_state seen[2];	/* connection parameters per direction */
46	u_int8_t	state;		/* state of the connection (enum tcp_conntrack) */
47	/* For detecting stale connections */
48	u_int8_t	last_dir;	/* Direction of the last packet (enum ip_conntrack_dir) */
49	u_int8_t	retrans;	/* Number of retransmitted packets */
50	u_int8_t	last_index;	/* Index of the last packet */
51	u_int32_t	last_seq;	/* Last sequence number seen in dir */
52	u_int32_t	last_ack;	/* Last sequence number seen in opposite dir */
53	u_int32_t	last_end;	/* Last seq + len */
54	u_int16_t	last_win;	/* Last window advertisement seen in dir */
55};
56
57#endif /* __KERNEL__ */
58
59#endif /* _NF_CONNTRACK_TCP_H */
60