misc/pax-utils.eclass: add a copy for the records

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+# Copyright 1999-2013 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Header: /var/cvsroot/gentoo-x86/eclass/pax-utils.eclass,v 1.21 2013/05/18 13:43:20 zorry Exp $
+
+# @ECLASS: pax-utils.eclass
+# @MAINTAINER:
+# The Gentoo Linux Hardened Team <hardened@gentoo.org>
+# @AUTHOR:
+# Original Author: Kevin F. Quinn <kevquinn@gentoo.org>
+# Modifications for bug #365825, @ ECLASS markup: Anthony G. Basile <blueness@gentoo.org>
+# Modifications for bug #431092: Anthony G. Basile <blueness@gentoo.org>
+# @BLURB: functions to provide pax markings
+# @DESCRIPTION:
+#
+# This eclass provides support for manipulating PaX markings on ELF binaries,
+# whether the system is using legacy PT_PAX markings or the newer XATTR_PAX.
+# The eclass wraps the use of paxctl-ng, paxctl, set/getattr and scanelf utilities,
+# deciding which to use depending on what's installed on the build host, and
+# whether we're working with PT_PAX, XATTR_PAX or both.
+#
+# To control what markings are made, set PAX_MARKINGS in /etc/portage/make.conf
+# to contain either "PT", "XT" or "none".  The default is to attempt both
+# PT_PAX and XATTR_PAX.
+
+if [[ ${___ECLASS_ONCE_PAX_UTILS} != "recur -_+^+_- spank" ]] ; then
+___ECLASS_ONCE_PAX_UTILS="recur -_+^+_- spank"
+
+# @ECLASS-VARIABLE: PAX_MARKINGS
+# @DESCRIPTION:
+# Control which markings are made:
+# PT = PT_PAX markings, XT = XATTR_PAX markings
+# Default to PT markings.
+PAX_MARKINGS=${PAX_MARKINGS:="PT"}
+
+# @FUNCTION: pax-mark
+# @USAGE: <flags> {<ELF files>}
+# @RETURN: Shell true if we succeed, shell false otherwise
+# @DESCRIPTION:
+# Marks <ELF files> with provided PaX <flags>
+#
+# Flags are passed directly to the utilities unchanged
+#
+#	p: disable PAGEEXEC		P: enable PAGEEXEC
+#	e: disable EMUTRAMP		E: enable EMUTRAMP
+#	m: disable MPROTECT		M: enable MPROTECT
+#	r: disable RANDMMAP		R: enable RANDMMAP
+#	s: disable SEGMEXEC		S: enable SEGMEXEC
+#
+# Default flags are 'PeMRS', which are the most restrictive settings.  Refer
+# to http://pax.grsecurity.net/ for details on what these flags are all about.
+#
+# Please confirm any relaxation of restrictions with the Gentoo Hardened team.
+# Either ask on the gentoo-hardened mailing list, or CC/assign hardened@g.o on
+# the bug report.
+pax-mark() {
+
+	local f								# loop over paxables
+	local flags							# pax flags
+	local pt_fail=0 pt_failures=""		# record PT_PAX failures
+	local xt_fail=0 xt_failures=""		# record xattr PAX marking failures
+	local ret=0							# overal return code of this function
+
+	# Only the actual PaX flags and z are accepted
+	# 1. The leading '-' is optional
+	# 2. -C -c only make sense for paxctl, but are unnecessary
+	#    because we progressively do -q -qc -qC
+	# 3. z is allowed for the default
+
+	flags="${1//[!zPpEeMmRrSs]}"
+	[[ "${flags}" ]] || return 0
+	shift
+
+	# z = default. For XATTR_PAX, the default is no xattr field at all
+	local dodefault=""
+	[[ "${flags//[!z]}" ]] && dodefault="yes"
+
+	if has PT ${PAX_MARKINGS}; then
+
+		#First try paxctl -> this might try to create/convert program headers
+		if type -p paxctl > /dev/null; then
+			einfo "PT PaX marking -${flags} with paxctl"
+			_pax_list_files einfo "$@"
+			for f in "$@"; do
+				# First, try modifying the existing PAX_FLAGS header
+				paxctl -q${flags} "${f}" && continue
+				# Second, try creating a PT_PAX header (works on ET_EXEC)
+				# Even though this is less safe, most exes need it, eg bug #463170
+				paxctl -qC${flags} "${f}" && continue
+				# Third, try stealing the (unused under PaX) PT_GNU_STACK header
+				paxctl -qc${flags} "${f}" && continue
+				pt_fail=1
+				pt_failures="${pt_failures} ${f}"
+			done
+
+		#Next try paxctl-ng -> this will not create/convert any program headers
+		elif type -p paxctl-ng > /dev/null && paxctl-ng -L ; then
+			einfo "PT PaX marking -${flags} with paxctl-ng"
+			flags="${flags//z}"
+			_pax_list_files einfo "$@"
+			for f in "$@"; do
+				[[ ${dodefault} == "yes" ]] && paxctl-ng -L -z "${f}"
+				[[ "${flags}" ]] || continue
+				paxctl-ng -L -${flags} "${f}" && continue
+				pt_fail=1
+				pt_failures="${pt_failures} ${f}"
+			done
+
+		#Finally fall back on scanelf
+		elif type -p scanelf > /dev/null && [[ ${PAX_MARKINGS} != "none" ]]; then
+			einfo "Fallback PaX marking -${flags} with scanelf"
+			_pax_list_files einfo "$@"
+			scanelf -Xxz ${flags} "$@"
+
+		#We failed to set PT_PAX flags
+		elif [[ ${PAX_MARKINGS} != "none" ]]; then
+			pt_failures="$*"
+			pt_fail=1
+		fi
+
+		if [[ ${pt_fail} == 1 ]]; then
+			elog "Failed to set PT_PAX markings -${flags} for:"
+			_pax_list_files elog ${pt_failures}
+			ret=1
+		fi
+	fi
+
+	if has XT ${PAX_MARKINGS}; then
+
+		flags="${flags//z}"
+
+		#First try paxctl-ng
+		if type -p paxctl-ng > /dev/null && paxctl-ng -l ; then
+			einfo "XT PaX marking -${flags} with paxctl-ng"
+			_pax_list_files einfo "$@"
+			for f in "$@"; do
+				[[ ${dodefault} == "yes" ]] && paxctl-ng -d "${f}"
+				[[ "${flags}" ]] || continue
+				paxctl-ng -l -${flags} "${f}" && continue
+				xt_fail=1
+				xt_failures="${tx_failures} ${f}"
+			done
+
+		#Next try setfattr
+		elif type -p setfattr > /dev/null; then
+			[[ "${flags//[!Ee]}" ]] || flags+="e" # bug 447150
+			einfo "XT PaX marking -${flags} with setfattr"
+			_pax_list_files einfo "$@"
+			for f in "$@"; do
+				[[ ${dodefault} == "yes" ]] && setfattr -x "user.pax.flags" "${f}"
+				setfattr -n "user.pax.flags" -v "${flags}" "${f}" && continue
+				xt_fail=1
+				xt_failures="${tx_failures} ${f}"
+			done
+
+		#We failed to set XATTR_PAX flags
+		elif [[ ${PAX_MARKINGS} != "none" ]]; then
+			xt_failures="$*"
+			xt_fail=1
+		fi
+
+		if [[ ${xt_fail} == 1 ]]; then
+			elog "Failed to set XATTR_PAX markings -${flags} for:"
+			_pax_list_files elog ${xt_failures}
+			ret=1
+		fi
+	fi
+
+	# [[ ${ret} == 1 ]] && elog "Executables may be killed by PaX kernels."
+
+	return ${ret}
+}
+
+# @FUNCTION: list-paxables
+# @USAGE: {<files>}
+# @RETURN: Subset of {<files>} which are ELF executables or shared objects
+# @DESCRIPTION:
+# Print to stdout all of the <files> that are suitable to have PaX flag
+# markings, i.e., filter out the ELF executables or shared objects from a list
+# of files.  This is useful for passing wild-card lists to pax-mark, although
+# in general it is preferable for ebuilds to list precisely which ELFS are to
+# be marked.  Often not all the ELF installed by a package need remarking.
+# @EXAMPLE:
+# pax-mark -m $(list-paxables ${S}/{,usr/}bin/*)
+list-paxables() {
+	file "$@" 2> /dev/null | grep -E 'ELF.*(executable|shared object)' | sed -e 's/: .*$//'
+}
+
+# @FUNCTION: host-is-pax
+# @RETURN: Shell true if the build process is PaX enabled, shell false otherwise
+# @DESCRIPTION:
+# This is intended for use where the build process must be modified conditionally
+# depending on whether the host is PaX enabled or not.  It is not intedened to
+# determine whether the final binaries need PaX markings.  Note: if procfs is
+# not mounted on /proc, this returns shell false (e.g. Gentoo/FBSD).
+host-is-pax() {
+	grep -qs ^PaX: /proc/self/status
+}
+
+
+# INTERNAL FUNCTIONS
+# ------------------
+#
+# These functions are for use internally by the eclass - do not use
+# them elsewhere as they are not supported (i.e. they may be removed
+# or their function may change arbitratily).
+
+# Display a list of things, one per line, indented a bit, using the
+# display command in $1.
+_pax_list_files() {
+	local f cmd
+	cmd=$1
+	shift
+	for f in "$@"; do
+		${cmd} "     ${f}"
+	done
+}
+
+fi