root/include/net/tcp.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. before
  2. after
  3. between
  4. tcp_connected

   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 module.
   7  *
   8  * Version:     @(#)tcp.h       1.0.5   05/23/93
   9  *
  10  * Authors:     Ross Biro, <bir7@leland.Stanford.Edu>
  11  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12  *
  13  *              This program is free software; you can redistribute it and/or
  14  *              modify it under the terms of the GNU General Public License
  15  *              as published by the Free Software Foundation; either version
  16  *              2 of the License, or (at your option) any later version.
  17  */
  18 #ifndef _TCP_H
  19 #define _TCP_H
  20 
  21 #include <linux/tcp.h>
  22 
  23 #define MAX_SYN_SIZE    44 + MAX_HEADER + 15
  24 #define MAX_FIN_SIZE    40 + MAX_HEADER + 15
  25 #define MAX_ACK_SIZE    40 + MAX_HEADER + 15
  26 #define MAX_RESET_SIZE  40 + MAX_HEADER + 15
  27 #define MAX_WINDOW      32767           /* Never offer a window over 32767 without using
  28                                            window scaling (not yet supported). Some poor
  29                                            stacks do signed 16bit maths! */
  30 #define MIN_WINDOW      2048
  31 #define MAX_ACK_BACKLOG 2
  32 #define MIN_WRITE_SPACE 2048
  33 #define TCP_WINDOW_DIFF 2048
  34 
  35 /* urg_data states */
  36 #define URG_VALID       0x0100
  37 #define URG_NOTYET      0x0200
  38 #define URG_READ        0x0400
  39 
  40 #define TCP_RETR1       7       /*
  41                                  * This is how many retries it does before it
  42                                  * tries to figure out if the gateway is
  43                                  * down.
  44                                  */
  45 
  46 #define TCP_RETR2       15      /*
  47                                  * This should take at least
  48                                  * 90 minutes to time out.
  49                                  */
  50 
  51 #define TCP_TIMEOUT_LEN (15*60*HZ) /* should be about 15 mins           */
  52 #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to successfully 
  53                                   * close the socket, about 60 seconds  */
  54 #define TCP_FIN_TIMEOUT (3*60*HZ) /* BSD style FIN_WAIT2 deadlock breaker */                              
  55 #define TCP_ACK_TIME    (3*HZ)  /* time to delay before sending an ACK  */
  56 #define TCP_DONE_TIME   250     /* maximum time to wait before actually
  57                                  * destroying a socket                  */
  58 #define TCP_WRITE_TIME  3000    /* initial time to wait for an ACK,
  59                                  * after last transmit                  */
  60 #define TCP_TIMEOUT_INIT (3*HZ) /* RFC 1122 initial timeout value       */
  61 #define TCP_SYN_RETRIES  10     /* number of times to retry opening a
  62                                  * connection   (TCP_RETR2-....)        */
  63 #define TCP_PROBEWAIT_LEN 100   /* time to wait between probes when
  64                                  * I've got something to write and
  65                                  * there is no window                   */
  66 
  67 #define TCP_NO_CHECK    0       /* turn to one if you want the default
  68                                  * to be no checksum                    */
  69 
  70 
  71 /*
  72  *      TCP option
  73  */
  74  
  75 #define TCPOPT_NOP              1       /* Padding */
  76 #define TCPOPT_EOL              0       /* End of options */
  77 #define TCPOPT_MSS              2       /* Segment size negotiating */
  78 /*
  79  *      We don't use these yet, but they are for PAWS and big windows
  80  */
  81 #define TCPOPT_WINDOW           3       /* Window scaling */
  82 #define TCPOPT_TIMESTAMP        8       /* Better RTT estimations/PAWS */
  83 
  84 
  85 /*
  86  * The next routines deal with comparing 32 bit unsigned ints
  87  * and worry about wraparound (automatic with unsigned arithmetic).
  88  */
  89 
  90 extern __inline int before(__u32 seq1, __u32 seq2)
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  91 {
  92         return (__s32)(seq1-seq2) < 0;
  93 }
  94 
  95 extern __inline int after(__u32 seq1, __u32 seq2)
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  96 {
  97         return (__s32)(seq1-seq2) > 0;
  98 }
  99 
 100 
 101 /* is s2<=s1<=s3 ? */
 102 extern __inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
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 103 {
 104         return (after(seq1+1, seq2) && before(seq1, seq3+1));
 105 }
 106 
 107 
 108 /*
 109  * List all states of a TCP socket that can be viewed as a "connected"
 110  * state.  This now includes TCP_SYN_RECV, although I am not yet fully
 111  * convinced that this is the solution for the 'getpeername(2)'
 112  * problem. Thanks to Stephen A. Wood <saw@cebaf.gov>  -FvK
 113  */
 114 
 115 extern __inline const int tcp_connected(const int state)
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 116 {
 117   return(state == TCP_ESTABLISHED || state == TCP_CLOSE_WAIT ||
 118          state == TCP_FIN_WAIT1   || state == TCP_FIN_WAIT2 ||
 119          state == TCP_SYN_RECV);
 120 }
 121 
 122 
 123 extern struct proto tcp_prot;
 124 
 125 
 126 extern void     tcp_err(int type, int code, unsigned char *header, __u32 daddr,
 127                         __u32, struct inet_protocol *protocol);
 128 extern void     tcp_shutdown (struct sock *sk, int how);
 129 extern int      tcp_rcv(struct sk_buff *skb, struct device *dev,
 130                         struct options *opt, __u32 daddr,
 131                         unsigned short len, __u32 saddr, int redo,
 132                         struct inet_protocol *protocol);
 133 
 134 extern int      tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 135 
 136 extern int tcp_select_window(struct sock *sk);
 137 extern void tcp_send_check(struct tcphdr *th, unsigned long saddr, 
 138                 unsigned long daddr, int len, struct sock *sk);
 139 extern void tcp_send_probe0(struct sock *sk);
 140 extern void tcp_enqueue_partial(struct sk_buff *, struct sock *);
 141 extern struct sk_buff * tcp_dequeue_partial(struct sock *);
 142 extern void tcp_cache_zap(void);
 143 
 144 #endif  /* _TCP_H */

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