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
24 #define MAX_FIN_SIZE 40 + MAX_HEADER
25 #define MAX_ACK_SIZE 40 + MAX_HEADER
26 #define MAX_RESET_SIZE 40 + MAX_HEADER
27 #define MAX_WINDOW 8192
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 how many 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 successfully
51 * close the socket, about 60 seconds */
52 #define TCP_ACK_TIME (3*HZ) /* 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_TIMEOUT_INIT (3*HZ) /* RFC 1122 initial timeout value */
58 #define TCP_SYN_RETRIES 5 /* number of times to retry opening 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
68 /*
69 * TCP option
70 */
71
72 #define TCPOPT_NOP 1
73 #define TCPOPT_EOL 0
74 #define TCPOPT_MSS 2
75
76 /*
77 * The next routines deal with comparing 32 bit unsigned ints
78 * and worry about wraparound (automatic with unsigned arithmetic).
79 */
80 static inline int before(unsigned long seq1, unsigned long seq2)
/* ![[previous]](../icons/n_left.png)
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*/
81 {
82 return (long)(seq1-seq2) < 0;
83 }
84
85 static inline int after(unsigned long seq1, unsigned long seq2)
/* ![[previous]](../icons/left.png)
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*/
86 {
87 return (long)(seq1-seq2) > 0;
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)
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*/
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)
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*/
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 tcp_err(int err, unsigned char *header, unsigned long daddr,
117 unsigned long saddr, struct inet_protocol *protocol);
118 extern void tcp_shutdown (struct sock *sk, int how);
119 extern int tcp_rcv(struct sk_buff *skb, struct device *dev,
120 struct options *opt, unsigned long daddr,
121 unsigned short len, unsigned long saddr, int redo,
122 struct inet_protocol *protocol);
123
124 extern int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);
125
126 extern int tcp_select_window(struct sock *sk);
127 extern void tcp_send_check(struct tcphdr *th, unsigned long saddr,
128 unsigned long daddr, int len, struct sock *sk);
129 extern void tcp_send_probe0(struct sock *sk);
130 extern void tcp_enqueue_partial(struct sk_buff *, struct sock *);
131 extern struct sk_buff * tcp_dequeue_partial(struct sock *);
132
133
134 #endif /* _TCP_H */