The C and C++ Include Header Files

/usr/include/linux/netfilter/nf_conntrack_tcp.h


$ cat -n /usr/include/linux/netfilter/nf_conntrack_tcp.h

     1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
     2	#ifndef _NF_CONNTRACK_TCP_H
     3	#define _NF_CONNTRACK_TCP_H
     4	/* TCP tracking. */
     5	
     6	#include <linux/types.h>
     7	
     8	/* This is exposed to userspace (ctnetlink) */
     9	enum tcp_conntrack {
    10		TCP_CONNTRACK_NONE,
    11		TCP_CONNTRACK_SYN_SENT,
    12		TCP_CONNTRACK_SYN_RECV,
    13		TCP_CONNTRACK_ESTABLISHED,
    14		TCP_CONNTRACK_FIN_WAIT,
    15		TCP_CONNTRACK_CLOSE_WAIT,
    16		TCP_CONNTRACK_LAST_ACK,
    17		TCP_CONNTRACK_TIME_WAIT,
    18		TCP_CONNTRACK_CLOSE,
    19		TCP_CONNTRACK_LISTEN,	/* obsolete */
    20	#define TCP_CONNTRACK_SYN_SENT2	TCP_CONNTRACK_LISTEN
    21		TCP_CONNTRACK_MAX,
    22		TCP_CONNTRACK_IGNORE,
    23		TCP_CONNTRACK_RETRANS,
    24		TCP_CONNTRACK_UNACK,
    25		TCP_CONNTRACK_TIMEOUT_MAX
    26	};
    27	
    28	/* Window scaling is advertised by the sender */
    29	#define IP_CT_TCP_FLAG_WINDOW_SCALE		0x01
    30	
    31	/* SACK is permitted by the sender */
    32	#define IP_CT_TCP_FLAG_SACK_PERM		0x02
    33	
    34	/* This sender sent FIN first */
    35	#define IP_CT_TCP_FLAG_CLOSE_INIT		0x04
    36	
    37	/* Be liberal in window checking */
    38	#define IP_CT_TCP_FLAG_BE_LIBERAL		0x08
    39	
    40	/* Has unacknowledged data */
    41	#define IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED	0x10
    42	
    43	/* The field td_maxack has been set */
    44	#define IP_CT_TCP_FLAG_MAXACK_SET		0x20
    45	
    46	/* Marks possibility for expected RFC5961 challenge ACK */
    47	#define IP_CT_EXP_CHALLENGE_ACK 		0x40
    48	
    49	/* Simultaneous open initialized */
    50	#define IP_CT_TCP_SIMULTANEOUS_OPEN		0x80
    51	
    52	struct nf_ct_tcp_flags {
    53		__u8 flags;
    54		__u8 mask;
    55	};
    56	
    57	
    58	#endif /* _NF_CONNTRACK_TCP_H */