nf_conntrack_tcp.h revision bfcaa50270e18f35220a11d46e98fc6232c24606 
1#ifndef _NF_CONNTRACK_TCP_H
2#define _NF_CONNTRACK_TCP_H
3/* TCP tracking. */
4
5#include <linux/types.h>
6
7/* This is exposed to userspace (ctnetlink) */
8enum tcp_conntrack {
9	TCP_CONNTRACK_NONE,
10	TCP_CONNTRACK_SYN_SENT,
11	TCP_CONNTRACK_SYN_RECV,
12	TCP_CONNTRACK_ESTABLISHED,
13	TCP_CONNTRACK_FIN_WAIT,
14	TCP_CONNTRACK_CLOSE_WAIT,
15	TCP_CONNTRACK_LAST_ACK,
16	TCP_CONNTRACK_TIME_WAIT,
17	TCP_CONNTRACK_CLOSE,
18	TCP_CONNTRACK_LISTEN,
19	TCP_CONNTRACK_MAX,
20	TCP_CONNTRACK_IGNORE
21};
22
23/* Window scaling is advertised by the sender */
24#define IP_CT_TCP_FLAG_WINDOW_SCALE		0x01
25
26/* SACK is permitted by the sender */
27#define IP_CT_TCP_FLAG_SACK_PERM		0x02
28
29/* This sender sent FIN first */
30#define IP_CT_TCP_FLAG_CLOSE_INIT		0x04
31
32/* Be liberal in window checking */
33#define IP_CT_TCP_FLAG_BE_LIBERAL		0x08
34
35/* Has unacknowledged data */
36#define IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED	0x10
37
38/* The field td_maxack has been set */
39#define IP_CT_TCP_FLAG_MAXACK_SET		0x20
40
41struct nf_ct_tcp_flags {
42	__u8 flags;
43	__u8 mask;
44};
45
46#ifdef __KERNEL__
47
48struct ip_ct_tcp_state {
49	u_int32_t	td_end;		/* max of seq + len */
50	u_int32_t	td_maxend;	/* max of ack + max(win, 1) */
51	u_int32_t	td_maxwin;	/* max(win) */
52	u_int32_t	td_maxack;	/* max of ack */
53	u_int8_t	td_scale;	/* window scale factor */
54	u_int8_t	flags;		/* per direction options */
55};
56
57struct ip_ct_tcp
58{
59	struct ip_ct_tcp_state seen[2];	/* connection parameters per direction */
60	u_int8_t	state;		/* state of the connection (enum tcp_conntrack) */
61	/* For detecting stale connections */
62	u_int8_t	last_dir;	/* Direction of the last packet (enum ip_conntrack_dir) */
63	u_int8_t	retrans;	/* Number of retransmitted packets */
64	u_int8_t	last_index;	/* Index of the last packet */
65	u_int32_t	last_seq;	/* Last sequence number seen in dir */
66	u_int32_t	last_ack;	/* Last sequence number seen in opposite dir */
67	u_int32_t	last_end;	/* Last seq + len */
68	u_int16_t	last_win;	/* Last window advertisement seen in dir */
69};
70
71#endif /* __KERNEL__ */
72
73#endif /* _NF_CONNTRACK_TCP_H */
74