1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NF_CONNTRACK_TCP_H
3#define _NF_CONNTRACK_TCP_H
4
5#include <uapi/linux/netfilter/nf_conntrack_tcp.h>
6
7
8struct ip_ct_tcp_state {
9 u_int32_t td_end; /* max of seq + len */
10 u_int32_t td_maxend; /* max of ack + max(win, 1) */
11 u_int32_t td_maxwin; /* max(win) */
12 u_int32_t td_maxack; /* max of ack */
13 u_int8_t td_scale; /* window scale factor */
14 u_int8_t flags; /* per direction options */
15};
16
17struct ip_ct_tcp {
18 struct ip_ct_tcp_state seen[2]; /* connection parameters per direction */
19 u_int8_t state; /* state of the connection (enum tcp_conntrack) */
20 /* For detecting stale connections */
21 u_int8_t last_dir; /* Direction of the last packet (enum ip_conntrack_dir) */
22 u_int8_t retrans; /* Number of retransmitted packets */
23 u_int8_t last_index; /* Index of the last packet */
24 u_int32_t last_seq; /* Last sequence number seen in dir */
25 u_int32_t last_ack; /* Last sequence number seen in opposite dir */
26 u_int32_t last_end; /* Last seq + len */
27 u_int16_t last_win; /* Last window advertisement seen in dir */
28 /* For SYN packets while we may be out-of-sync */
29 u_int8_t last_wscale; /* Last window scaling factor seen */
30 u_int8_t last_flags; /* Last flags set */
31};
32
33#endif /* _NF_CONNTRACK_TCP_H */
34

source code of linux/include/linux/netfilter/nf_conntrack_tcp.h