freebsd-src/lib/libsys/cap_fcntls_limit.2
Brooks Davis 8269e7673c libsys: relocate implementations and manpages
Remove core system call implementations and documentation to lib/libsys
and lib/libsys/<arch> from lib/libc/sys and lib/libc/<arch>/<sys>.
Update paths to allow libc to find them in their new home.

Reviewed by:	kib, emaste, imp
Pull Request:	https://github.com/freebsd/freebsd-src/pull/908
2024-02-05 20:34:55 +00:00

133 lines
3.4 KiB
Groff

.\"
.\" Copyright (c) 2012 The FreeBSD Foundation
.\"
.\" This documentation was written by Pawel Jakub Dawidek under sponsorship
.\" the FreeBSD Foundation.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
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.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
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.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.Dd March 9, 2023
.Dt CAP_FCNTLS_LIMIT 2
.Os
.Sh NAME
.Nm cap_fcntls_limit ,
.Nm cap_fcntls_get
.Nd manage allowed fcntl commands
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/capsicum.h
.Ft int
.Fn cap_fcntls_limit "int fd" "uint32_t fcntlrights"
.Ft int
.Fn cap_fcntls_get "int fd" "uint32_t *fcntlrightsp"
.Sh DESCRIPTION
If a file descriptor is granted the
.Dv CAP_FCNTL
capability right, the list of allowed
.Xr fcntl 2
commands can be selectively reduced (but never expanded) with the
.Fn cap_fcntls_limit
system call.
.Pp
A bitmask of allowed fcntls commands for a given file descriptor can be obtained
with the
.Fn cap_fcntls_get
system call.
.Sh FLAGS
The following flags may be specified in the
.Fa fcntlrights
argument or returned in the
.Fa fcntlrightsp
argument:
.Bl -tag -width CAP_FCNTL_GETOWN
.It Dv CAP_FCNTL_GETFL
Permit
.Dv F_GETFL
command.
.It Dv CAP_FCNTL_SETFL
Permit
.Dv F_SETFL
command.
.It Dv CAP_FCNTL_GETOWN
Permit
.Dv F_GETOWN
command.
.It Dv CAP_FCNTL_SETOWN
Permit
.Dv F_SETOWN
command.
.El
.Sh RETURN VALUES
.Rv -std
.Sh ERRORS
.Fn cap_fcntls_limit
succeeds unless:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid descriptor.
.It Bq Er EINVAL
An invalid flag has been passed in
.Fa fcntlrights .
.It Bq Er ENOTCAPABLE
.Fa fcntlrights
would expand the list of allowed
.Xr fcntl 2
commands.
.El
.Pp
.Fn cap_fcntls_get
succeeds unless:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid descriptor.
.It Bq Er EFAULT
The
.Fa fcntlrightsp
argument points at an invalid address.
.It Bq Er ENOSYS
The running kernel was compiled without
.Cd "options CAPABILITY_MODE" .
.El
.Sh SEE ALSO
.Xr cap_ioctls_limit 2 ,
.Xr cap_rights_limit 2 ,
.Xr fcntl 2
.Sh HISTORY
The
.Fn cap_fcntls_get
and
.Fn cap_fcntls_limit
system calls first appeared in
.Fx 8.3 .
Support for capabilities and capabilities mode was developed as part of the
.Tn TrustedBSD
Project.
.Sh AUTHORS
This function was created by
.An Pawel Jakub Dawidek Aq Mt pawel@dawidek.net
under sponsorship of the FreeBSD Foundation.