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 + 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 #define TCP_RETR1 7 /*
34 * This is howmany retries it does before it
35 * tries to figure out if the gateway is
36 * down.
37 */
38
39 #define TCP_RETR2 15 /*
40 * This should take at least
41 * 90 minutes to time out.
42 */
43
44 #define TCP_TIMEOUT_LEN (15*60*HZ) /* should be about 15 mins */
45 #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to sucessfully
46 * close the socket, about 60 seconds */
47 #define TCP_ACK_TIME 3000 /* time to delay before sending an ACK */
48 #define TCP_DONE_TIME 250 /* maximum time to wait before actually
49 * destroying a socket */
50 #define TCP_WRITE_TIME 3000 /* initial time to wait for an ACK,
51 * after last transmit */
52 #define TCP_CONNECT_TIME 2000 /* time to retransmit first SYN */
53 #define TCP_SYN_RETRIES 5 /* number of times to retry openning a
54 * connection */
55 #define TCP_PROBEWAIT_LEN 100 /* time to wait between probes when
56 * I've got something to write and
57 * there is no window */
58
59 #define TCP_NO_CHECK 0 /* turn to one if you want the default
60 * to be no checksum */
61
62 #define TCP_WRITE_QUEUE_MAGIC 0xa5f23477
63
64 /*
65 * TCP option
66 */
67
68 #define TCPOPT_NOP 1
69 #define TCPOPT_EOL 0
70 #define TCPOPT_MSS 2
71
72 /*
73 * The next routines deal with comparing 32 bit unsigned ints
74 * and worry about wraparound (automatic with unsigned arithmetic).
75 */
76 static inline int before(unsigned long seq1, unsigned long seq2)
/* ![[previous]](../icons/n_left.png)
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*/
77 {
78 /* this inequality is strict. */
79 if (seq1 == seq2)
80 return 0;
81 seq2 -= seq1;
82 return (seq2 < 65536);
83 }
84
85 static inline int after(unsigned long seq1, unsigned long seq2)
/* ![[previous]](../icons/left.png)
![[next]](../icons/right.png)
![[first]](../icons/first.png)
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![[top]](../icons/top.png)
![[bottom]](../icons/bottom.png)
![[index]](../icons/index.png)
*/
86 {
87 return before(seq2, seq1);
88 }
89
90
91 /* is s2<=s1<=s3 ? */
92 static inline int between(unsigned long seq1, unsigned long seq2, unsigned long seq3)
/* ![[previous]](../icons/left.png)
![[next]](../icons/right.png)
![[first]](../icons/first.png)
![[last]](../icons/last.png)
![[top]](../icons/top.png)
![[bottom]](../icons/bottom.png)
![[index]](../icons/index.png)
*/
93 {
94 return (after(seq1+1, seq2) && before(seq1, seq3+1));
95 }
96
97
98 /*
99 * List all states of a TCP socket that can be viewed as a "connected"
100 * state. This now includes TCP_SYN_RECV, although I am not yet fully
101 * convinced that this is the solution for the 'getpeername(2)'
102 * problem. Thanks to Stephen A. Wood <saw@cebaf.gov> -FvK
103 */
104 static inline const int
105 tcp_connected(const int state)
/* ![[previous]](../icons/left.png)
![[next]](../icons/n_right.png)
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![[last]](../icons/n_last.png)
![[top]](../icons/top.png)
![[bottom]](../icons/bottom.png)
![[index]](../icons/index.png)
*/
106 {
107 return(state == TCP_ESTABLISHED || state == TCP_CLOSE_WAIT ||
108 state == TCP_FIN_WAIT1 || state == TCP_FIN_WAIT2 ||
109 state == TCP_SYN_RECV);
110 }
111
112
113 extern struct proto tcp_prot;
114
115
116 extern void print_th(struct tcphdr *);
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 */