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) */ 8 enum 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, /* obsolete */ 19 #define TCP_CONNTRACK_SYN_SENT2 TCP_CONNTRACK_LISTEN 20 TCP_CONNTRACK_MAX, 21 TCP_CONNTRACK_IGNORE 22 }; 23 24 /* Window scaling is advertised by the sender */ 25 #define IP_CT_TCP_FLAG_WINDOW_SCALE 0x01 26 27 /* SACK is permitted by the sender */ 28 #define IP_CT_TCP_FLAG_SACK_PERM 0x02 29 30 /* This sender sent FIN first */ 31 #define IP_CT_TCP_FLAG_CLOSE_INIT 0x04 32 33 /* Be liberal in window checking */ 34 #define IP_CT_TCP_FLAG_BE_LIBERAL 0x08 35 36 /* Has unacknowledged data */ 37 #define IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED 0x10 38 39 /* The field td_maxack has been set */ 40 #define IP_CT_TCP_FLAG_MAXACK_SET 0x20 41 42 struct nf_ct_tcp_flags { 43 __u8 flags; 44 __u8 mask; 45 }; 46 47 #ifdef __KERNEL__ 48 49 struct ip_ct_tcp_state { 50 u_int32_t td_end; /* max of seq + len */ 51 u_int32_t td_maxend; /* max of ack + max(win, 1) */ 52 u_int32_t td_maxwin; /* max(win) */ 53 u_int32_t td_maxack; /* max of ack */ 54 u_int8_t td_scale; /* window scale factor */ 55 u_int8_t flags; /* per direction options */ 56 }; 57 58 struct ip_ct_tcp { 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 /* For SYN packets while we may be out-of-sync */ 70 u_int8_t last_wscale; /* Last window scaling factor seen */ 71 u_int8_t last_flags; /* Last flags set */ 72 }; 73 74 #endif /* __KERNEL__ */ 75 76 #endif /* _NF_CONNTRACK_TCP_H */ 77