include/linux/netfilter/nf_conntrack_tcp.h

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