include/linux/tcp.h

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              Definitions for the TCP protocol.
   7  *
   8  * Version:     @(#)tcp.h       1.0.2   04/28/93
   9  *
  10  * Author:      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  11  *
  12  *              This program is free software; you can redistribute it and/or
  13  *              modify it under the terms of the GNU General Public License
  14  *              as published by the Free Software Foundation; either version
  15  *              2 of the License, or (at your option) any later version.
  16  */
  17 #ifndef _LINUX_TCP_H
  18 #define _LINUX_TCP_H
  19
  20 #include <linux/types.h>
  21 #include <asm/byteorder.h>
  22
  23 struct tcphdr {
  24         __u16   source;
  25         __u16   dest;
  26         __u32   seq;
  27         __u32   ack_seq;
  28 #if defined(__LITTLE_ENDIAN_BITFIELD)
  29         __u16   res1:4,
  30                 doff:4,
  31                 fin:1,
  32                 syn:1,
  33                 rst:1,
  34                 psh:1,
  35                 ack:1,
  36                 urg:1,
  37                 res2:2;
  38 #elif defined(__BIG_ENDIAN_BITFIELD)
  39         __u16   doff:4,
  40                 res1:4,
  41                 res2:2,
  42                 urg:1,
  43                 ack:1,
  44                 psh:1,
  45                 rst:1,
  46                 syn:1,
  47                 fin:1;
  48 #else
  49 #error  "Adjust your <asm/byteorder.h> defines"
  50 #endif
  51         __u16   window;
  52         __u16   check;
  53         __u16   urg_ptr;
  54 };
  55
  56
  57 enum {
  58   TCP_ESTABLISHED = 1,
  59   TCP_SYN_SENT,
  60   TCP_SYN_RECV,
  61   TCP_FIN_WAIT1,
  62   TCP_FIN_WAIT2,
  63   TCP_TIME_WAIT,
  64   TCP_CLOSE,
  65   TCP_CLOSE_WAIT,
  66   TCP_LAST_ACK,
  67   TCP_LISTEN,
  68   TCP_CLOSING,   /* now a valid state */
  69
  70   TCP_MAX_STATES /* Leave at the end! */
  71 };
  72
  73 #define TCP_STATE_MASK  0xF
  74 #define TCP_ACTION_FIN  (1 << 7)
  75
  76 enum {
  77   TCPF_ESTABLISHED = (1 << 1),
  78   TCPF_SYN_SENT  = (1 << 2),
  79   TCPF_SYN_RECV  = (1 << 3),
  80   TCPF_FIN_WAIT1 = (1 << 4),
  81   TCPF_FIN_WAIT2 = (1 << 5),
  82   TCPF_TIME_WAIT = (1 << 6),
  83   TCPF_CLOSE     = (1 << 7),
  84   TCPF_CLOSE_WAIT = (1 << 8),
  85   TCPF_LAST_ACK  = (1 << 9),
  86   TCPF_LISTEN    = (1 << 10),
  87   TCPF_CLOSING   = (1 << 11)
  88 };
  89
  90 /*
  91  *      The union cast uses a gcc extension to avoid aliasing problems
  92  *  (union is compatible to any of its members)
  93  *  This means this part of the code is -fstrict-aliasing safe now.
  94  */
  95 union tcp_word_hdr {
  96         struct tcphdr hdr;
  97         __u32             words[5];
  98 };
  99
 100 #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
 101
 102 enum {
 103         TCP_FLAG_URG = __constant_htonl(0x00200000),
 104         TCP_FLAG_ACK = __constant_htonl(0x00100000),
 105         TCP_FLAG_PSH = __constant_htonl(0x00080000),
 106         TCP_FLAG_RST = __constant_htonl(0x00040000),
 107         TCP_FLAG_SYN = __constant_htonl(0x00020000),
 108         TCP_FLAG_FIN = __constant_htonl(0x00010000),
 109         TCP_RESERVED_BITS = __constant_htonl(0x0FC00000),
 110         TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
 111 };
 112
 113 #endif  /* _LINUX_TCP_H */