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Annotated edit history of x25(7) version 1, including all changes. View license author blame.
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1 perry 1 X25
2 !!!X25
3 NAME
4 SYNOPSIS
5 DESCRIPTION
6 SOCKET ADDRESSES
7 SOCKET OPTIONS
8 BUGS
9 SEE ALSO
10 VERSIONS
11 ----
12 !!NAME
13
14
15 x25, PF_X25 - ITU-T X.25 / ISO-8208 protocol interface.
16 !!SYNOPSIS
17
18
19 __#include __
20 #include __
21
22
23 __x25_socket = socket(PF_X25, SOCK_SEQPACKET,
24 0);__
25 !!DESCRIPTION
26
27
28 X25 sockets provide an interface to the X.25 packet layer
29 protocol. This allows applications to communicate over a
30 public X.25 data network as standardised by International
31 Telecommunication Union's recommendation X.25 (X.25 DTE-DCE
32 mode). X25 sockets can also be used for communication
33 without an intermediate X.25 network (X.25 DTE-DTE mode) as
34 described in ISO-8208.
35
36
37 Message boundaries are preserved - a read(2) from a
38 socket will retrieve the same chunk of data as output with
39 the corresponding __write(2)__ to the peer socket. When
40 necessary, the kernel takes care of segmenting and
41 re-assembling long messages by means of the X.25 M-bit.
42 There is no hard-coded upper limit for the message size.
43 However, re-assembling of a long message might fail if there
44 is a temporary lack of system resources or when other
45 constraints (such as socket memory or buffer size limits)
46 become effective. If that occurs, the X.25 connection will
47 be reset.
48 !!SOCKET ADDRESSES
49
50
51 The __AF_X25__ socket address family uses the __struct
52 sockaddr_x25__ for representing network addresses as
53 defined in ITU-T recommendation X.121.
54
55
56 struct sockaddr_x25 {
57 sa_family_t sx25_family; /* must be AF_X25 */
58 x25_address sx25_addr; /* X.121 Address */
59 };
60
61
62 ''sx25_addr'' contains a char array ''x25_addr[[]'' to
63 be interpretated as a null-terminated string.
64 ''sx25_addr.x25_addr[[]'' consists of up to 15 (not
65 counting the terminating 0) ASCII characters forming the
66 X.121 address. Only the decimal digit characters from `0' to
67 `9' are allowed.
68 !!SOCKET OPTIONS
69
70
71 The following X.25 specific socket options can be set by
72 using setsockopt(2) and read with
73 getsockopt(2) with the level parameter set to
74 __SOL_X25__.
75
76
77 __X25_QBITINCL__
78
79
80 Controls whether the X.25 Q-bit (Qualified Data Bit) is
81 accessible by the user. It expects an integer argument. If
82 set to 0 (default), the Q-bit is never set for outgoing
83 packets and the Q-bit of incoming packets is ignored. If set
84 to 1, an additional first byte is prepended to each message
85 read from or written to the socket. For data read from the
86 socket, a 0 first byte indicates that the Q-bits of the
87 corresponding incoming data packets were not set. A first
88 byte with value 1 indicates that the Q-bit of the
89 corresponding incoming data packets was set. If the first
90 byte of the data written to the socket is 1 the Q-bit of the
91 corresponding outgoing data packets will be set. If the
92 first bit is 0 the Q-bit will not be set.
93 !!BUGS
94
95
96 Plenty, as the X.25 PLP implementation is
97 __CONFIG_EXPERIMENTAL__.
98
99
100 This man page is incomplete.
101
102
103 There is no dedicated application programmer's header file
104 yet; you need to include the kernel header file
105 ____. __CONFIG_EXPERIMENTAL__ might
106 also imply that future versions of the interface are not
107 binary compatible.
108
109
110 X.25 N-Reset events are not propagated to the user process
111 yet. Thus, if a reset occurred, data might be lost without
112 notice.
113 !!SEE ALSO
114
115
116 socket(7), socket(2)
117
118
119 Jonathan Simon Naylor: ``The Re-Analysis and
120 Re-Implementation of X.25.'' The URL is
121
122
123 ''ftp://ftp.pspt.fi/pub/ham/linux/ax25/x25doc.tgz''
124 !!VERSIONS
125
126
127 The PF_X25 protocol family is a new feature of Linux
128 2.2.
129 ----
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