include/linux/netfilter_ipv4/ip_conntrack_tcp.h

   1 #ifndef _IP_CONNTRACK_TCP_H
   2 #define _IP_CONNTRACK_TCP_H
   3 /* TCP tracking. */
   4
   5 enum tcp_conntrack {
   6         TCP_CONNTRACK_NONE,
   7         TCP_CONNTRACK_SYN_SENT,
   8         TCP_CONNTRACK_SYN_RECV,
   9         TCP_CONNTRACK_ESTABLISHED,
  10         TCP_CONNTRACK_FIN_WAIT,
  11         TCP_CONNTRACK_CLOSE_WAIT,
  12         TCP_CONNTRACK_LAST_ACK,
  13         TCP_CONNTRACK_TIME_WAIT,
  14         TCP_CONNTRACK_CLOSE,
  15         TCP_CONNTRACK_LISTEN,
  16         TCP_CONNTRACK_MAX,
  17         TCP_CONNTRACK_IGNORE
  18 };
  19
  20 /* Window scaling is advertised by the sender */
  21 #define IP_CT_TCP_FLAG_WINDOW_SCALE             0x01
  22
  23 /* SACK is permitted by the sender */
  24 #define IP_CT_TCP_FLAG_SACK_PERM                0x02
  25
  26 /* This sender sent FIN first */
  27 #define IP_CT_TCP_FLAG_CLOSE_INIT               0x03
  28
  29 struct ip_ct_tcp_state {
  30         u_int32_t       td_end;         /* max of seq + len */
  31         u_int32_t       td_maxend;      /* max of ack + max(win, 1) */
  32         u_int32_t       td_maxwin;      /* max(win) */
  33         u_int8_t        td_scale;       /* window scale factor */
  34         u_int8_t        loose;          /* used when connection picked up from the middle */
  35         u_int8_t        flags;          /* per direction options */
  36 };
  37
  38 struct ip_ct_tcp
  39 {
  40         struct ip_ct_tcp_state seen[2]; /* connection parameters per direction */
  41         u_int8_t        state;          /* state of the connection (enum tcp_conntrack) */
  42         /* For detecting stale connections */
  43         u_int8_t        last_dir;       /* Direction of the last packet (enum ip_conntrack_dir) */
  44         u_int8_t        retrans;        /* Number of retransmitted packets */
  45         u_int8_t        last_index;     /* Index of the last packet */
  46         u_int32_t       last_seq;       /* Last sequence number seen in dir */
  47         u_int32_t       last_ack;       /* Last sequence number seen in opposite dir */
  48         u_int32_t       last_end;       /* Last seq + len */
  49 };
  50
  51 #endif /* _IP_CONNTRACK_TCP_H */