From 3d08cd331c1adcf0d917392f7e527b3f00511748 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 24 May 2024 06:52:22 +0200 Subject: Merging upstream version 6.8. Signed-off-by: Daniel Baumann --- man/man7/x25.7 | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 man/man7/x25.7 (limited to 'man/man7/x25.7') diff --git a/man/man7/x25.7 b/man/man7/x25.7 new file mode 100644 index 0000000..920865c --- /dev/null +++ b/man/man7/x25.7 @@ -0,0 +1,124 @@ +.\" SPDX-License-Identifier: Linux-man-pages-1-para +.\" +.\" This man page is Copyright (C) 1998 Heiner Eisen. +.\" +.\" $Id: x25.7,v 1.4 1999/05/18 10:35:12 freitag Exp $ +.\" +.TH x25 7 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +x25 +\- +ITU-T X.25 / ISO/IEC\~8208 protocol interface +.SH SYNOPSIS +.nf +.B #include +.B #include +.P +.IB x25_socket " = socket(AF_X25, SOCK_SEQPACKET, 0);" +.fi +.SH DESCRIPTION +X25 sockets provide an interface to the X.25 packet layer protocol. +This allows applications to +communicate over a public X.25 data network as standardized by +International Telecommunication Union's recommendation X.25 +(X.25 DTE-DCE mode). +X25 sockets can also be used for communication +without an intermediate X.25 network (X.25 DTE-DTE mode) as described +in ISO/IEC\~8208. +.P +Message boundaries are preserved \[em] a +.BR read (2) +from a socket will +retrieve the same chunk of data as output with the corresponding +.BR write (2) +to the peer socket. +When necessary, the kernel takes care +of segmenting and reassembling long messages by means of +the X.25 M-bit. +There is no hard-coded upper limit for the +message size. +However, reassembling of a long message might fail if +there is a temporary lack of system resources or when other constraints +(such as socket memory or buffer size limits) become effective. +If that +occurs, the X.25 connection will be reset. +.SS Socket addresses +The +.B AF_X25 +socket address family uses the +.I struct sockaddr_x25 +for representing network addresses as defined in ITU-T +recommendation X.121. +.P +.in +4n +.EX +struct sockaddr_x25 { + sa_family_t sx25_family; /* must be AF_X25 */ + x25_address sx25_addr; /* X.121 Address */ +}; +.EE +.in +.P +.I sx25_addr +contains a char array +.I x25_addr[] +to be interpreted as a null-terminated string. +.I sx25_addr.x25_addr[] +consists of up to 15 (not counting the terminating null byte) ASCII +characters forming the X.121 address. +Only the decimal digit characters from \[aq]0\[aq] to \[aq]9\[aq] are allowed. +.SS Socket options +The following X.25-specific socket options can be set by using +.BR setsockopt (2) +and read with +.BR getsockopt (2) +with the +.I level +argument set to +.BR SOL_X25 . +.TP +.B X25_QBITINCL +Controls whether the X.25 Q-bit (Qualified Data Bit) is accessible by the +user. +It expects an integer argument. +If set to 0 (default), +the Q-bit is never set for outgoing packets and the Q-bit of incoming +packets is ignored. +If set to 1, an additional first byte is prepended +to each message read from or written to the socket. +For data read from +the socket, a 0 first byte indicates that the Q-bits of the corresponding +incoming data packets were not set. +A first byte with value 1 indicates +that the Q-bit of the corresponding incoming data packets was set. +If the first byte of the data written to the socket is 1, the Q-bit of the +corresponding outgoing data packets will be set. +If the first byte is 0, +the Q-bit will not be set. +.SH VERSIONS +The AF_X25 protocol family is a new feature of Linux 2.2. +.SH BUGS +Plenty, as the X.25 PLP implementation is +.BR CONFIG_EXPERIMENTAL . +.P +This man page is incomplete. +.P +There is no dedicated application programmer's header file yet; +you need to include the kernel header file +.IR . +.B CONFIG_EXPERIMENTAL +might also imply that future versions of the +interface are not binary compatible. +.P +X.25 N-Reset events are not propagated to the user process yet. +Thus, +if a reset occurred, data might be lost without notice. +.SH SEE ALSO +.BR socket (2), +.BR socket (7) +.P +Jonathan Simon Naylor: +\[lq]The Re-Analysis and Re-Implementation of X.25.\[rq] +The URL is +.UR ftp://ftp.pspt.fi\:/pub\:/ham\:/linux\:/ax25\:/x25doc.tgz +.UE . -- cgit v1.2.3