From: Mike Frysinger <vapier@gentoo.org>
To: gentoo-dev@lists.gentoo.org
Cc: constanze@gentoo.org
Subject: [gentoo-dev] fcaps.eclass: bringing filesystem capabilities to the tree
Date: Fri, 25 Jan 2013 18:51:44 -0500 [thread overview]
Message-ID: <201301251851.45021.vapier@gentoo.org> (raw)
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i've taken Constanze' work and rewritten it a bit to be easier to use (imo) as
most settings are now defaults
-mike
# Copyright 1999-2013 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $
# @ECLASS: fcaps.eclass
# @MAINTAINER:
# Constanze Hausner <constanze@gentoo.org>
# base-system@gentoo.org
# @BLURB: function to set POSIX file-based capabilities
# @DESCRIPTION:
# This eclass provides a function to set file-based capabilities on binaries.
#
# Due to probable capability-loss on moving or copying, this happens in
# pkg_postinst-phase (at least for now).
#
# @EXAMPLE:
# You can manually set the caps on ping and ping6 by doing:
# @CODE
# pkg_postinst() {
# fcaps cap_net_raw bin/ping bin/ping6
# }
# @CODE
#
# Or set it via the global ebuild var FILECAPS:
# @CODE
# FILECAPS=(
# cap_net_raw bin/ping bin/ping6
# )
# @CODE
if [[ ${___ECLASS_ONCE_FCAPS} != "recur -_+^+_- spank" ]] ; then
___ECLASS_ONCE_FCAPS="recur -_+^+_- spank"
IUSE="+filecaps"
DEPEND="filecaps? ( sys-libs/libcap )"
# @ECLASS-VARIABLE: FILECAPS
# @DEFAULT_UNSET
# @DESCRIPTION:
# An array of fcap arguments to use to automatically execute fcaps. See that
# function for more details.
#
# All args are consumed until the '--' marker is found. So if you have:
# @CODE
# FILECAPS=( moo cow -- fat cat -- chubby penguin )
# @CODE
#
# This will end up executing:
# @CODE
# fcaps moo cow
# fcaps fat cat
# fcaps chubby penguin
# @CODE
#
# Note: If you override pkg_postinst, you must call fcaps_pkg_postinst yourself.
# @FUNCTION: fcaps
# @USAGE: [-o <owner>] [-g <group>] [-m <mode>] <capabilities> <file[s]>
# @DESCRIPTION:
# Sets the specified capabilities on the specified files.
#
# The caps option takes the form as expected by the cap_from_text(3) man page.
# If no action is specified, then "=ep" will be used as a default.
#
# If the file is a relative path (e.g. bin/foo rather than /bin/foo), then the
# appropriate path var ($D/$ROOT/etc...) will be prefixed based on the current
# ebuild phase.
#
# If the system is unable to set capabilities, it will use the specified user,
# group, and mode (presumably to make the binary set*id). The defaults there
# are root:root and 4711. Otherwise, the ownership and permissions will be
# unchanged.
fcaps() {
debug-print-function ${FUNCNAME} "$@"
# Process the user options first.
local owner='root'
local group='root'
local mode='4711'
while [[ $# -gt 0 ]] ; do
case $1 in
-o) owner=$2; shift;;
-g) group=$2; shift;;
-m) mode=$2; shift;;
*) break;;
esac
shift
done
[[ $# -lt 2 ]] && die "${FUNCNAME}: wrong arg count"
local caps=$1
[[ ${caps} == *[-=+]* ]] || caps+="=ep"
shift
local root
case ${EBUILD_PHASE} in
compile|install|preinst)
root=${ED:-${D}}
;;
postinst)
root=${EROOT:-${ROOT}}
;;
esac
# Process every file!
local file out
for file ; do
[[ ${file} != /* ]] && file="${root}${file}"
if use filecaps ; then
# Try to set capabilities. Ignore errors when the
# fs doesn't support it, but abort on all others.
debug-print "${FUNCNAME}: setting caps '${caps}' on '${file}'"
if ! out=$(LC_ALL=C setcap "${caps}" "${file}" 2>&1) ; then
if [[ ${out} != *"Operation not supported"* ]] ; then
eerror "Setting caps '${caps}' on file '${file}' failed:"
eerror "${out}"
die "could not set caps"
else
local fstype=$(stat -f -c %T "${file}")
ewarn "Could not set caps on '${file}' due to missing filesystem support."
ewarn "Make sure you enable XATTR support for '${fstype}' in your kernel."
fi
else
# Sanity check that everything took.
setcap -v "${caps}" "${file}" >/dev/null \
|| die "Checking caps '${caps}' on '${file}' failed"
# Everything worked. Move on to the next file.
continue
fi
fi
# If we're still here, setcaps failed.
debug-print "${FUNCNAME}: setting owner/mode on '${file}'"
chown "${owner}:${group}" "${file}" || die
chmod ${mode} "${file}" || die
done
}
# @FUNCTION: fcaps_pkg_postinst
# @DESCRIPTION:
# Process the FILECAPS array.
fcaps_pkg_postinst() {
local arg args=()
for arg in "${FILECAPS[@]}" "--" ; do
if [[ ${arg} == "--" ]] ; then
fcaps "${args[@]}"
args=()
else
args+=( "${arg}" )
fi
done
}
EXPORT_FUNCTIONS pkg_postinst
fi
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next reply other threads:[~2013-01-25 23:51 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-25 23:51 Mike Frysinger [this message]
2013-01-26 0:10 ` [gentoo-dev] fcaps.eclass: bringing filesystem capabilities to the tree Gilles Dartiguelongue
2013-01-26 0:17 ` Diego Elio Pettenò
2013-01-26 7:46 ` Mike Frysinger
2013-01-26 10:17 ` [gentoo-dev] " Duncan
2013-01-26 16:01 ` [gentoo-dev] " Diego Elio Pettenò
2013-01-26 16:13 ` Rich Freeman
2013-01-26 17:02 ` Diego Elio Pettenò
2013-01-28 19:58 ` Gilles Dartiguelongue
2013-01-26 13:21 ` Michał Górny
2013-01-26 17:08 ` Mike Frysinger
2013-01-26 21:07 ` Doug Goldstein
2013-01-27 17:26 ` Mike Frysinger
2013-01-27 18:24 ` Kacper Kowalik
2013-01-29 12:14 ` [gentoo-dev] " Duncan
2013-01-30 0:47 ` Diego Elio Pettenò
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