mirror of https://github.com/mkerrisk/man-pages
104 lines
3.1 KiB
Groff
104 lines
3.1 KiB
Groff
.\" Copyright (C) 2007, Michael Kerrisk <mtk.manpages@gmail.com>
|
|
.\" and Copyright (C) 2008, Linux Foundation, written by Michael Kerrisk
|
|
.\" <mtk.manpages@gmail.com>
|
|
.\"
|
|
.\" %%%LICENSE_START(VERBATIM)
|
|
.\" Permission is granted to make and distribute verbatim copies of this
|
|
.\" manual provided the copyright notice and this permission notice are
|
|
.\" preserved on all copies.
|
|
.\"
|
|
.\" Permission is granted to copy and distribute modified versions of this
|
|
.\" manual under the conditions for verbatim copying, provided that the
|
|
.\" entire resulting derived work is distributed under the terms of a
|
|
.\" permission notice identical to this one.
|
|
.\"
|
|
.\" Since the Linux kernel and libraries are constantly changing, this
|
|
.\" manual page may be incorrect or out-of-date. The author(s) assume no
|
|
.\" responsibility for errors or omissions, or for damages resulting from
|
|
.\" the use of the information contained herein. The author(s) may not
|
|
.\" have taken the same level of care in the production of this manual,
|
|
.\" which is licensed free of charge, as they might when working
|
|
.\" professionally.
|
|
.\"
|
|
.\" Formatted or processed versions of this manual, if unaccompanied by
|
|
.\" the source, must acknowledge the copyright and authors of this work.
|
|
.\" %%%LICENSE_END
|
|
.\"
|
|
.\" 2007-05-31, mtk: Rewrite and substantial additional text.
|
|
.\" 2008-12-03, mtk: Rewrote some pieces and fixed some errors
|
|
.\"
|
|
.TH BINDRESVPORT 3 2008-12-03 "" "Linux Programmer's Manual"
|
|
.SH NAME
|
|
bindresvport \- bind a socket to a privileged IP port
|
|
.SH SYNOPSIS
|
|
.nf
|
|
.B #include <sys/types.h>
|
|
.B #include <netinet/in.h>
|
|
.LP
|
|
.BI "int bindresvport(int " sockfd ", struct sockaddr_in *" sin );
|
|
.fi
|
|
.SH DESCRIPTION
|
|
.LP
|
|
.BR bindresvport ()
|
|
is used to bind a socket descriptor to a privileged anonymous IP port,
|
|
that is, a port number arbitrarily selected from the range 512 to 1023.
|
|
.\" Glibc actually starts searching with a port # in the range 600 to 1023
|
|
|
|
If the
|
|
.BR bind (2)
|
|
performed by
|
|
.BR bindresvport ()
|
|
is successful, and
|
|
.I sin
|
|
is not NULL, then
|
|
.I sin\->sin_port
|
|
returns the port number actually allocated.
|
|
|
|
.I sin
|
|
can be NULL, in which case
|
|
.I sin\->sin_family
|
|
is implicitly taken to be
|
|
.BR AF_INET .
|
|
However, in this case,
|
|
.BR bindresvport ()
|
|
has no way to return the port number actually allocated.
|
|
(This information can later be obtained using
|
|
.BR getsockname (2).)
|
|
.SH RETURN VALUE
|
|
.BR bindresvport ()
|
|
returns 0 on success; otherwise \-1 is returned and
|
|
.I errno
|
|
set to indicate the cause of the error.
|
|
.SH ERRORS
|
|
.BR bindresvport ()
|
|
can fail for any of the same reasons as
|
|
.BR bind (2).
|
|
In addition, the following errors may occur:
|
|
.TP
|
|
.BR EACCES
|
|
The caller did not have superuser privilege (to be precise: the
|
|
.B CAP_NET_BIND_SERVICE
|
|
capability is required).
|
|
.TP
|
|
.B EADDRINUSE
|
|
All privileged ports are in use.
|
|
.TP
|
|
.BR EAFNOSUPPORT " (" EPFNOSUPPORT " in glibc 2.7 and earlier)"
|
|
.I sin
|
|
is not NULL and
|
|
.I sin->sin_family
|
|
is not
|
|
.BR AF_INET .
|
|
.SH CONFORMING TO
|
|
Not in POSIX.1-2001.
|
|
Present on the BSDs, Solaris, and many other systems.
|
|
.SH NOTES
|
|
Unlike some
|
|
.BR bindresvport ()
|
|
implementations,
|
|
the glibc implementation ignores any value that the caller supplies in
|
|
.IR sin\->sin_port .
|
|
.SH SEE ALSO
|
|
.BR bind (2),
|
|
.BR getsockname (2)
|