tcp.h

An implementation of the TCP/IP protocol suite for the LINUX operating system. INET is implemented u

  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, <[e-mail]>
 11  *              Fred N. van Kempen, <[e-mail]>
 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 + sizeof (struct sk_buff) + MAX_HEADER
 24 #define MAX_FIN_SIZE    40 + sizeof (struct sk_buff) + MAX_HEADER
 25 #define MAX_ACK_SIZE    40 + sizeof (struct sk_buff) + MAX_HEADER
 26 #define MAX_RESET_SIZE  40 + sizeof (struct sk_buff) + MAX_HEADER
 27 #define MAX_WINDOW      4096
 28 #define MIN_WINDOW      2048
 29 #define MAX_ACK_BACKLOG 2
 30 #define MIN_WRITE_SPACE 2048
 31 #define TCP_WINDOW_DIFF 2048
 32 
 33 /* urg_data states */
 34 #define URG_VALID       0x0100
 35 #define URG_NOTYET      0x0200
 36 #define URG_READ        0x0400
 37 
 38 #define TCP_RETR1       7       /*
 39                                  * This is howmany retries it does before it
 40                                  * tries to figure out if the gateway is
 41                                  * down.
 42                                  */
 43 
 44 #define TCP_RETR2       15      /*
 45                                  * This should take at least
 46                                  * 90 minutes to time out.
 47                                  */
 48 
 49 #define TCP_TIMEOUT_LEN (15*60*HZ) /* should be about 15 mins           */
 50 #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to sucessfully 
 51                                   * close the socket, about 60 seconds  */
 52 #define TCP_ACK_TIME    3000    /* time to delay before sending an ACK  */
 53 #define TCP_DONE_TIME   250     /* maximum time to wait before actually
 54                                  * destroying a socket                  */
 55 #define TCP_WRITE_TIME  3000    /* initial time to wait for an ACK,
 56                                  * after last transmit                  */
 57 #define TCP_CONNECT_TIME 2000   /* time to retransmit first SYN         */
 58 #define TCP_SYN_RETRIES 5       /* number of times to retry openning a
 59                                  * connection                           */
 60 #define TCP_PROBEWAIT_LEN 100   /* time to wait between probes when
 61                                  * I've got something to write and
 62                                  * there is no window                   */
 63 
 64 #define TCP_NO_CHECK    0       /* turn to one if you want the default
 65                                  * to be no checksum                    */
 66 
 67 #define TCP_WRITE_QUEUE_MAGIC 0xa5f23477
 68 
 69 /*
 70  *      TCP option
 71  */
 72  
 73 #define TCPOPT_NOP              1
 74 #define TCPOPT_EOL              0
 75 #define TCPOPT_MSS              2
 76 
 77 /*
 78  * The next routines deal with comparing 32 bit unsigned ints
 79  * and worry about wraparound (automatic with unsigned arithmetic).
 80  */
 81 static inline int before(unsigned long seq1, unsigned long seq2)
 82 {
 83         return (long)(seq1-seq2) < 0;
 84 }
 85 
 86 static inline int after(unsigned long seq1, unsigned long seq2)
 87 {
 88         return (long)(seq1-seq2) > 0;
 89 }
 90 
 91 
 92 /* is s2<=s1<=s3 ? */
 93 static inline int between(unsigned long seq1, unsigned long seq2, unsigned long seq3)
 94 {
 95         return (after(seq1+1, seq2) && before(seq1, seq3+1));
 96 }
 97 
 98 
 99 /*
100  * List all states of a TCP socket that can be viewed as a "connected"
101  * state.  This now includes TCP_SYN_RECV, although I am not yet fully
102  * convinced that this is the solution for the 'getpeername(2)'
103  * problem. Thanks to Stephen A. Wood <[e-mail]>  -FvK
104  */
105 static inline const int
106 tcp_connected(const int state)
107 {
108   return(state == TCP_ESTABLISHED || state == TCP_CLOSE_WAIT ||
109          state == TCP_FIN_WAIT1   || state == TCP_FIN_WAIT2 ||
110          state == TCP_SYN_RECV);
111 }
112 
113 
114 extern struct proto tcp_prot;
115 
116 
117 extern void     tcp_err(int err, unsigned char *header, unsigned long daddr,
118                         unsigned long saddr, struct inet_protocol *protocol);
119 extern void     tcp_shutdown (struct sock *sk, int how);
120 extern int      tcp_rcv(struct sk_buff *skb, struct device *dev,
121                         struct options *opt, unsigned long daddr,
122                         unsigned short len, unsigned long saddr, int redo,
123                         struct inet_protocol *protocol);
124 
125 extern int      tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);
126 
127 extern void tcp_send_probe0(struct sock *sk);
128 extern void tcp_enqueue_partial(struct sk_buff *, struct sock *);
129 extern struct sk_buff * tcp_dequeue_partial(struct sock *);
130 
131 
132 #endif  /* _TCP_H */
133