160 lines
4.8 KiB
Groff
160 lines
4.8 KiB
Groff
.\" $NetBSD: fsetown.9,v 1.5 2003/10/14 14:59:03 wiz Exp $
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.\"
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.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
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.\" All rights reserved.
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.\"
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.\" This code is derived from software contributed to The NetBSD Foundation
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.\" by Jaromir Dolecek.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the NetBSD
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.\" Foundation, Inc. and its contributors.
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.\" 4. Neither the name of The NetBSD Foundation nor the names of its
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.\" contributors may be used to endorse or promote products derived
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.\" from this software without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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.\" POSSIBILITY OF SUCH DAMAGE.
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.\"
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.Dd September 22, 2003
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.Dt FSETOWN 9
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.Os
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.Sh NAME
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.Nm fsetown ,
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.Nm fgetown ,
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.Nm fownsignal
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.Nd file descriptor owner handling functions
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.Sh SYNOPSIS
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.In sys/file.h
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.Ft int
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.Fn fsetown "struct proc *p" "pid_t *pgid" "int cmd" "const void *data"
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.Ft int
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.Fn fgetown "struct proc *p" "pid_t pgid" "int cmd" "void *data"
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.Ft void
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.Fn fownsignal "pid_t pgid" "int signo" "int code" "int band" "void *fdescdata"
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.Sh DESCRIPTION
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These functions handle file descriptor owner related ioctls and
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related signal delivery.
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Device drivers and other parts of the kernel call these functions from
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ioctl entry functions or I/O notification functions.
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.Pp
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.Fn fsetown
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sets the owner of file.
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.Fa cmd
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is an ioctl command, one of
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.Dv SIOCSPGRP ,
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.Dv FIOSETOWN ,
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and
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.Dv TIOCSPGRP .
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.Fa data
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is interpreted as a pointer to a signed integer, the integer being
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the ID of the owner.
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The
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.Fa cmd
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determines how exactly
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.Fa data
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should be interpreted.
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If
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.Fa cmd
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is
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.Dv TIOCSPGRP ,
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the ID needs to be positive and is interpreted as process group ID.
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For
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.Dv SIOCSPGRP
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and
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.Dv FIOSETOWN ,
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the passed ID is the process ID if positive, or the process group ID
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if negative.
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.Pp
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.Fn fgetown
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returns the current owner of the file.
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.Fa cmd
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is an ioctl command, one of
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.Dv SIOCGPGRP ,
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.Dv FIOGETOWN ,
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and
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.Dv TIOCGPGRP .
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.Fa data
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is interpreted as a pointer to a signed integer,
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and the value is set according to the passed
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.Fa cmd .
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For
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.Dv TIOCGPGRP ,
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the returned
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.Fa data
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value is positive process group ID if the owner is the process group,
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or negative process ID if the owner is a process.
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For other ioctls,
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the returned value is the positive process ID if the owner is a process,
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or the negative process group ID if the owner is a process group.
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.Pp
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.Fn fownsignal
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schedules the
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.Fa signo
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signal to be sent to the current file descriptor owner.
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The signals typically used with this function are
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.Dv SIGIO
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and
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.Dv SIGURG .
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The
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.Fa code
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and
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.Fa band
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arguments are sent along with the signal as additional signal specific
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information if
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.Dv SA_SIGINFO
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is activated.
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If the information is not available from the context of the
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.Fn fownsignal
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call, these should be passed as zero.
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.Fa fdescdata
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is used to lookup the file descriptor for
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.Sa SA_SIGINFO
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signals.
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If it is specified, the file descriptor number is sent along with
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the signal as additional signal specific information.
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If file descriptor data pointer is not available in the context of the
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.Fn fownsignal
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call,
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.Dv NULL
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should be used instead.
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.Pp
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Note that a
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.Xr fcntl 2
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.Dv F_SETOWN request
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is translated by the kernel to a
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.Dv FIOSETOWN
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ioctl, and
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.Dv F_GETOWN
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is translated to
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.Dv FIOGETOWN .
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This is done transparently by generic code, before the device- or
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subsystem-specific ioctl entry function is called.
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.Sh SEE ALSO
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.Xr fcntl 2 ,
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.Xr siginfo 2 ,
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.Xr signal 7 ,
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.Xr ioctl 9 ,
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.Xr signal 9
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.Sh HISTORY
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These kernel functions appeared in
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.Nx 2.0 .
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