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#!/bin/sh
# Make sure cp -p isn't too generous with existing file permissions.
# Copyright (C) 2006-2010 Free Software Foundation, Inc.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
. "${srcdir=.}/init.sh"; path_prepend_ ../src
print_ver_ cp
require_membership_in_two_groups_
# cp -p gives ENOTSUP on NFS on Linux 2.6.9 at least
require_local_dir_
set _ $groups; shift
g1=$1
g2=$2
umask 077
mkfifo fifo ||
skip_test_ "fifos not supported"
touch fifo-copy &&
chgrp $g1 fifo &&
chgrp $g2 fifo-copy &&
chmod g+r fifo-copy || framework-failure
# Copy a fifo's contents. That way, we can examine the
# destination permissions before they're finalized.
cp -p --copy-contents fifo fifo-copy &
cp_pid=$!
(
# Now 'cp' is reading the fifo. Wait for the destination file to
# be written to, encouraging things along by echoing to the fifo.
while test ! -s fifo-copy; do
echo foo
done
# Check the permissions of the destination.
ls -l -n fifo-copy >ls.out &&
# Close the fifo so that "cp" can continue. But output first,
# before exiting, otherwise some shells would optimize away the file
# descriptor that holds the fifo open.
echo foo
) >fifo || fail=1
# Check that the destination mode is safe while the file is being copied.
read mode links owner group etc <ls.out || fail=1
case $mode in
-rw-------*) ;;
# FIXME: Remove the following case; the file mode should always be
# 600 while the data are being copied. This will require changing
# cp so that it also does not put $g1's data in a file that is
# accessible to $g2. This fix will not close a security hole, since
# a $g2 process can maintain an open file descriptor to the
# destination, but it's safer anyway.
-rw-r-----*)
# If the file has group $g1 and is group-readable, that is definitely
# bogus, as neither the source nor the destination was readable to group $g1.
test "$group" = "$g1" && fail=1;;
*) fail=1;;
esac
wait $cp_pid || fail=1
# Check that the final mode and group are right.
ls -l -n fifo-copy >ls.out &&
read mode links owner group etc <ls.out || fail=1
case $mode in
-rw-------*) test "$group" = "$g1" || fail=1;;
*) fail=1;;
esac
Exit $fail
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