net/tcp/tcp.h

/* */
This source file includes following definitions.
before
after
between
   1 /* tcp.h */
   2 /*
   3     Copyright (C) 1992  Ross Biro
   4 
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2, or (at your option)
   8     any later version.
   9 
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14 
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
  18 
  19     The Author may be reached as bir7@leland.stanford.edu or
  20     C/O Department of Mathematics; Stanford University; Stanford, CA 94305
  21 */
  22 #ifndef _TCP_TCP_H
  23 #define _TCP_TCP_H
  24 
  25 struct tcp_header
  26 {
  27   unsigned short source;
  28   unsigned short dest;
  29   unsigned long seq;
  30   unsigned long ack_seq;
  31   unsigned short res1:4, doff:4, fin:1, syn:1, rst:1, psh:1,
  32                  ack:1, urg:1,res2:2;
  33   unsigned short window;
  34   unsigned short check;
  35   unsigned short urg_ptr;
  36 };
  37 
  38 enum {
  39   TCP_ESTABLISHED=1,
  40   TCP_SYN_SENT,
  41   TCP_SYN_RECV,
  42   TCP_CLOSING, /* not a valid state, just a seperator so we can use
  43                   < tcp_closing or > tcp_closing for checks. */
  44   TCP_FIN_WAIT1,
  45   TCP_FIN_WAIT2,
  46   TCP_TIME_WAIT,
  47   TCP_CLOSE,
  48   TCP_LAST_ACK,
  49   TCP_LISTEN
  50 };
  51 
  52 #define MAX_SYN_SIZE 44 + sizeof (struct sk_buff) + MAX_HEADER
  53 #define MAX_FIN_SIZE 40 + sizeof (struct sk_buff) + MAX_HEADER
  54 #define MAX_ACK_SIZE 40 + sizeof (struct sk_buff) + MAX_HEADER
  55 #define MAX_RESET_SIZE 40 + sizeof (struct sk_buff) + MAX_HEADER
  56 #define MAX_WINDOW  12000
  57 #define MIN_WINDOW   2048
  58 #define MAX_ACK_BACKLOG 2
  59 #define MIN_WRITE_SPACE 2048
  60 #define TCP_WINDOW_DIFF 2048
  61 
  62 #define TCP_RETR1       7       /* this is howmany retries it does
  63                                    before it tries to figure out
  64                                    if the gateway is down. */
  65 
  66 #define TCP_RETR2      10       /* this should take between 3 and
  67                                    ten minutes ( 1024 * rtt). */
  68 
  69 
  70 #define TCP_TIMEOUT_LEN 720000 /* should be about 2 hrs. */
  71 #define TCP_TIMEWAIT_LEN 6000 /* How long to wait to sucessfully 
  72                                  close the socket, about 60 seconds. */
  73 #define TCP_ACK_TIME 35 /* time to delay before sending an ack. */
  74 #define TCP_DONE_TIME 2500 /* maximum time to wait before actually destroying
  75                              a socket. */
  76 #define TCP_WRITE_TIME 100 /* initial time to wait for an ack,
  77                               after last transmit. */
  78 #define TCP_CONNECT_TIME 200 /* time to retransmit first syn. */
  79 #define TCP_SYN_RETRIES 30 /* number of times to retry openning a connection.
  80                               */
  81 
  82 #define TCP_NO_CHECK 0 /* turn to one if you want the default to be no
  83                           checksum . */
  84 
  85 void print_th (struct tcp_header *);
  86 #define HEADER_SIZE 64
  87 
  88 
  89  /* this next routines deal with comparing 32 bit unsigned ints and
  90     worry about wrap around. The general strategy is to do a normal
  91     compare so long as neither of the numbers is within 4k of wrapping.
  92     Otherwise we must check for the wrap. */
  93 
  94  static inline int
  95  before (unsigned long seq1, unsigned long seq2)
     /*  */
  96  {
  97    /* this inequality is strict. */
  98    if (seq1 == seq2) return (0);
  99    if (seq1 < seq2) 
 100      {
 101        if ((unsigned long)seq2-(unsigned long)seq1 < 32767UL) 
 102          {
 103            return (1);
 104          }
 105        else
 106          {
 107            return (0);
 108          }
 109      }
 110    /* now we know seq1 > seq2.  So all we need to do is check to see
 111       if seq1 has wrapped. */
 112    if (seq2 < 4096UL && seq1 > (0xffffffUL - 4096UL))
 113      {
 114        return (1);
 115      }
 116    return (0);
 117 
 118  }
 119 
 120  static inline int
 121  after (unsigned long seq1, unsigned long seq2)
     /*  */
 122  {
 123    return (before (seq2, seq1));
 124  }
 125 
 126  /* is s2<=s1<=s3 ? */
 127  static inline int
 128  between (unsigned long seq1, unsigned long seq2, unsigned long seq3)
     /*  */
 129  {
 130    return (after (seq1+1, seq2) && before (seq1, seq3+1));
 131  }
 132 
 133 #endif
/* */
root/net/tcp/tcp.h

INCLUDED FROM

DEFINITIONS
