prepstrip: preserve xattrs, bug #446420

2 files changed, 206 insertions, 3 deletions

diff --git a/bin/ebuild-helpers/prepstrip b/bin/ebuild-helpers/prepstrip
index 6a09ff457..fb20777e8 100755
--- a/bin/ebuild-helpers/prepstrip
+++ b/bin/ebuild-helpers/prepstrip
@@ -15,7 +15,7 @@ exp_tf() {
 		eval ${var}_${flag}=$(tf has ${flag} ${!var})
 	done
 }
-exp_tf FEATURES compressdebug installsources nostrip splitdebug
+exp_tf FEATURES compressdebug installsources nostrip splitdebug xattr
 exp_tf RESTRICT binchecks installsources strip
 
 if ! ___eapi_has_prefix_variables; then
@@ -30,6 +30,28 @@ if ${RESTRICT_strip} || ${FEATURES_nostrip} ; then
 	${FEATURES_installsources} || exit 0
 fi
 
+PRESERVE_XATTR=false
+if [[ ${KERNEL} == linux ]] && ${FEATURES_xattr} ; then
+	PRESERVE_XATTR=true
+	if type -P getfattr >/dev/null && type -P setfattr >/dev/null ; then
+		dump_xattrs() {
+			getfattr -d --absolute-names "$1"
+		}
+		restore_xattrs() {
+			setfattr --restore=-
+		}
+	else
+		dump_xattrs() {
+			"${PORTAGE_PYTHON:-/usr/bin/python}" \
+			"${PORTAGE_BIN_PATH}/xattr-helper.py" --dump < <(echo -n "$1")
+		}
+		restore_xattrs() {
+			"${PORTAGE_PYTHON:-/usr/bin/python}" \
+			"${PORTAGE_BIN_PATH}/xattr-helper.py" --restore
+		}
+	fi
+fi
+
 # look up the tools we might be using
 for t in STRIP:strip OBJCOPY:objcopy READELF:readelf ; do
 	v=${t%:*} # STRIP
@@ -152,7 +174,7 @@ save_elf_debug() {
 # Usage: process_elf <elf>
 process_elf() {
 	local x=$1 inode_link=$2 strip_flags=${*:3}
-	local already_stripped lockfile
+	local already_stripped lockfile xt_data
 
 	__vecho "   ${x:${#ED}}"
 
@@ -171,7 +193,12 @@ process_elf() {
 
 	[ -f "${inode_link}_stripped" ] && already_stripped=true || already_stripped=false
 
-	${already_stripped} || save_elf_sources "${x}"
+	if ! ${already_stripped} ; then
+		if ${PRESERVE_XATTR} ; then
+			xt_data=$(dump_xattrs "${x}")
+		fi
+		save_elf_sources "${x}"
+	fi
 
 	if ${strip_this} ; then
 
@@ -197,6 +224,9 @@ process_elf() {
 		ln "${inode_link}_stripped" "${x}" || die "ln failed unexpectedly"
 	else
 		ln "${x}" "${inode_link}_stripped" || die "ln failed unexpectedly"
+		if [[ ${xt_data} ]] ; then
+			restore_xattrs <<< "${xt_data}"
+		fi
 	fi
 
 	[[ -n ${lockfile} ]] && rm -f "${lockfile}"
diff --git a/bin/xattr-helper.py b/bin/xattr-helper.py
new file mode 100755
index 000000000..d40217c9a
--- /dev/null
+++ b/bin/xattr-helper.py
@@ -0,0 +1,173 @@
+#!/usr/bin/python
+# Copyright 2012 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+import array
+import optparse
+import os
+import re
+import sys
+
+if hasattr(os, "getxattr"):
+
+	class xattr(object):
+		get = os.getxattr
+		set = os.setxattr
+		list = os.listxattr
+
+else:
+	import xattr
+
+_unquote_re = re.compile(br'\\[0-7]{3}')
+_fs_encoding = sys.getfilesystemencoding()
+
+if sys.hexversion < 0x3000000:
+
+	def octal_quote_byte(b):
+		return b'\\%03o' % ord(b)
+
+	def unicode_encode(s):
+		if isinstance(s, unicode):
+			s = s.encode(_fs_encoding)
+		return s
+else:
+
+	def octal_quote_byte(b):
+		return ('\\%03o' % ord(b)).encode('ascii')
+
+	def unicode_encode(s):
+		if isinstance(s, str):
+			s = s.encode(_fs_encoding)
+		return s
+
+def quote(s, quote_chars):
+
+	quote_re = re.compile(b'[' + quote_chars + b']')
+	result = []
+	pos = 0
+	s_len = len(s)
+
+	while pos < s_len:
+		m = quote_re.search(s, pos=pos)
+		if m is None:
+			result.append(s[pos:])
+			pos = s_len
+		else:
+			start = m.start()
+			result.append(s[pos:start])
+			result.append(octal_quote_byte(s[start:start+1]))
+			pos = start + 1
+
+	return b"".join(result)
+
+def unquote(s):
+
+	result = []
+	pos = 0
+	s_len = len(s)
+
+	while pos < s_len:
+		m = _unquote_re.search(s, pos=pos)
+		if m is None:
+			result.append(s[pos:])
+			pos = s_len
+		else:
+			start = m.start()
+			result.append(s[pos:start])
+			pos = start + 4
+			a = array.array('B')
+			a.append(int(s[start + 1:pos], 8))
+			try:
+				# Python >= 3.2
+				result.append(a.tobytes())
+			except AttributeError:
+				result.append(a.tostring())
+
+	return b"".join(result)
+
+def dump_xattrs(file_in, file_out):
+
+	for pathname in file_in.read().split(b'\0'):
+		if not pathname:
+			continue
+
+		attrs = xattr.list(pathname)
+		if not attrs:
+			continue
+		file_out.write(b'# file: ' + quote(pathname, b'\n\r') + b'\n')
+		for attr in attrs:
+			attr = unicode_encode(attr)
+			file_out.write(quote(attr, b'=\n\r') + b'="' +
+				quote(xattr.get(pathname, attr), b'\\\0\n\r"') + b'"\n')
+
+def restore_xattrs(file_in):
+
+	pathname = None
+	for i, line in enumerate(file_in):
+		if line.startswith(b'# file: '):
+			pathname = unquote(line.rstrip(b'\n')[8:])
+		else:
+			parts = line.split(b'=', 1)
+			if len(parts) == 2:
+				if pathname is None:
+					raise AssertionError('line %d: missing pathname' % i + 1)
+				attr = unquote(parts[0])
+				# strip trailing newline and quotes 
+				value = unquote(parts[1].rstrip(b'\n')[1:-1])
+				xattr.set(pathname, attr, value)
+			elif line.strip():
+				raise AssertionError("line %d: malformed entry" % i + 1)
+
+def main(argv):
+
+	description = "Dump and restore extended attributes," \
+		" using format like that used by getfattr --dump."
+	usage = "usage: %s [--dump | --restore]\n" % \
+		os.path.basename(argv[0])
+
+	parser = optparse.OptionParser(description=description, usage=usage)
+
+	actions = optparse.OptionGroup(parser, 'Actions')
+	actions.add_option("--dump",
+		action="store_true",
+		help="Dump the values of all extended "
+			"attributes associated with null-separated"
+			" paths read from stdin.")
+	actions.add_option("--restore",
+		action="store_true",
+		help="Restore extended attributes using"
+			" a dump read from stdin.")
+	parser.add_option_group(actions)
+
+	options, args = parser.parse_args(argv[1:])
+
+	if len(args) != 0:
+		parser.error("expected zero arguments, "
+			"got %s" % len(args))
+
+	if sys.hexversion >= 0x3000000:
+		file_in = sys.stdin.buffer.raw
+	else:
+		file_in = sys.stdin
+
+	if options.dump:
+
+		if sys.hexversion >= 0x3000000:
+			file_out = sys.stdout.buffer
+		else:
+			file_out = sys.stdout
+
+		dump_xattrs(file_in, file_out)
+
+	elif options.restore:
+
+		restore_xattrs(file_in)
+
+	else:
+		parser.error("available actions: --dump, --restore")
+
+	return os.EX_OK
+
+if __name__ == "__main__":
+	rval = main(sys.argv[:])
+	sys.exit(rval)