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,   /* 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 {
  60         struct ip_ct_tcp_state seen[2]; /* connection parameters per direction */
  61         u_int8_t        state;          /* state of the connection (enum tcp_conntrack) */
  62         /* For detecting stale connections */
  63         u_int8_t        last_dir;       /* Direction of the last packet (enum ip_conntrack_dir) */
  64         u_int8_t        retrans;        /* Number of retransmitted packets */
  65         u_int8_t        last_index;     /* Index of the last packet */
  66         u_int32_t       last_seq;       /* Last sequence number seen in dir */
  67         u_int32_t       last_ack;       /* Last sequence number seen in opposite dir */
  68         u_int32_t       last_end;       /* Last seq + len */
  69         u_int16_t       last_win;       /* Last window advertisement seen in dir */
  70 };
  71
  72 #endif /* __KERNEL__ */
  73
  74 #endif /* _NF_CONNTRACK_TCP_H */