#ifndef _NF_CONNTRACK_TCP_H

#define _NF_CONNTRACK_TCP_H

/* TCP tracking. */

#include <linux/types.h>

/* This is exposed to userspace (ctnetlink) */

enum tcp_conntrack {

	TCP_CONNTRACK_NONE,

	TCP_CONNTRACK_SYN_SENT,

	TCP_CONNTRACK_SYN_RECV,

	TCP_CONNTRACK_ESTABLISHED,

	TCP_CONNTRACK_FIN_WAIT,

	TCP_CONNTRACK_CLOSE_WAIT,

	TCP_CONNTRACK_LAST_ACK,

	TCP_CONNTRACK_TIME_WAIT,

	TCP_CONNTRACK_CLOSE,

	TCP_CONNTRACK_LISTEN,	/* obsolete */

#define TCP_CONNTRACK_SYN_SENT2	TCP_CONNTRACK_LISTEN

	TCP_CONNTRACK_MAX,

	TCP_CONNTRACK_IGNORE,

	TCP_CONNTRACK_RETRANS,

	TCP_CONNTRACK_UNACK,

	TCP_CONNTRACK_TIMEOUT_MAX

};

/* Window scaling is advertised by the sender */

#define IP_CT_TCP_FLAG_WINDOW_SCALE		0x01

/* SACK is permitted by the sender */

#define IP_CT_TCP_FLAG_SACK_PERM		0x02

/* This sender sent FIN first */

#define IP_CT_TCP_FLAG_CLOSE_INIT		0x04

/* Be liberal in window checking */

#define IP_CT_TCP_FLAG_BE_LIBERAL		0x08

/* Has unacknowledged data */

#define IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED	0x10

/* The field td_maxack has been set */

#define IP_CT_TCP_FLAG_MAXACK_SET		0x20

struct nf_ct_tcp_flags {

	__u8 flags;

	__u8 mask;

};

#ifdef __KERNEL__

struct ip_ct_tcp_state {

	u_int32_t	td_end;		/* max of seq + len */

	u_int32_t	td_maxend;	/* max of ack + max(win, 1) */

	u_int32_t	td_maxwin;	/* max(win) */

	u_int32_t	td_maxack;	/* max of ack */

	u_int8_t	td_scale;	/* window scale factor */

	u_int8_t	flags;		/* per direction options */

};

struct ip_ct_tcp {

	struct ip_ct_tcp_state seen[2];	/* connection parameters per direction */

	u_int8_t	state;		/* state of the connection (enum tcp_conntrack) */

	/* For detecting stale connections */

	u_int8_t	last_dir;	/* Direction of the last packet (enum ip_conntrack_dir) */

	u_int8_t	retrans;	/* Number of retransmitted packets */

	u_int8_t	last_index;	/* Index of the last packet */

	u_int32_t	last_seq;	/* Last sequence number seen in dir */

	u_int32_t	last_ack;	/* Last sequence number seen in opposite dir */

	u_int32_t	last_end;	/* Last seq + len */

	u_int16_t	last_win;	/* Last window advertisement seen in dir */

	/* For SYN packets while we may be out-of-sync */

	u_int8_t	last_wscale;	/* Last window scaling factor seen */

	u_int8_t	last_flags;	/* Last flags set */

};

#endif /* __KERNEL__ */

#endif /* _NF_CONNTRACK_TCP_H */