selinux: adjust utils to run restorecon with -Z

cp, mv, install, mkdir, mkfifo, mknod are adjusted so that:
 -Z no longer accepts an argument.
 -Z or --context without an argument do not warn without SELinux.
 --context with an argument will warn without SELinux.

* src/local.mk: Reference the new selinux module where required.
* src/system.h: Make the argument to --context optional.
* src/mkdir.c: Likewise.  Also handle the SMACK case for --context.
Note we currently silently ignore -Z with SMACK.
* src/mkfifo.c: Likewise.
* src/mknod.c: Likewise.
* src/install.c: Likewise.  Note install(1) by default already
set the context for target files to their system default,
albeit with an older method.  Use the -Z option to select between
the old and new context restoration behavior, and document
the differences and details for how context restoration
is done in new and old methods, with a view disabling the
old method entirely in future.
* src/cp.c: Make the argument to --context optional.
Note -Z implies --no-preserve=context.  I.E. -Z overrides
that aspect of -a no matter what order specified.
(struct cp_options): Document the context handling options.
(main): Check/adjust option combinations after all
options are processed, to both simplify processing
and to make handling independent of order of options
on the command line.  Also improve the diagnostics
from a failed call to setfscreatecon().
(set_process_security_ctx): A new function,
refactored to set the default context from the source file,
or with the type adjusted as per the system default for
the destination path.
(set_file_security_ctx): A new function refactored to
set the security context of an existing file, either based on
the process context or the default system context for a path.
(copy_internal): Use the refactored functions to simplify
error handling and consistently fail or warn as needed.
(copy_reg): Likewise.
(copy_internal): With --preserve=context, also copy
context from non regular files.  Note for directories this may
impact the copying of subsequent files to that directory?
(copy_attr): If we're handling SELinux explicitly,
then exclude to avoid the redudant copy with --preserve=context,
and the problematic copy with -Z.  Note SELinux attribute exclusion
also now honors cp -a --no-preserve=context.  Note there was a
very small window over 10 years ago, where attr_copy_file was
available, while attr_copy_check_permissions was not, so we
don't bother adding an explicit m4 check for the latter function.
* src/mv.c: Support --context, but don't allow specifying an argument.
* src/chcon.c: Adjust a comment to be specific to SELinux.
* src/runcon.c: Likewise.
* src/copy.c: Honor the context settings to "restorecon" as appropriate.
* src/copy.h: Add a new setting to select "restorecon" functionality.
* tests/mkdir/selinux.sh: s/-Z/--context=/
* tests/cp/cp-a-selinux.sh: Augment this test with cases
testing basic -Z functionality, and also test the various
invalid option combinations and option precedence.
* tests/mkdir/restorecon.sh: Add a new test for the
more involved mkdir -Z handling, since the directory changing
and non existent directories need to be specially handled.
Also check the similar but simpler handling of -Z by mk{nod,fifo}.
* tests/local.mk: Reference the new test.
* doc/coreutils.texi (cp invocation): Update as per interface changes.
(mv invocation): Likewise.
(install invocation): Likewise.
(mkfifo invocation): Likewise.
(mknod invocation): Likewise.
(mkdir invocation): Likewise.
* NEWS: Mention the new feature and change in behavior.

2 files changed, 73 insertions, 1 deletions

diff --git a/tests/mkdir/restorecon.sh b/tests/mkdir/restorecon.sh
new file mode 100755
index 000000000..01a647736
--- /dev/null
+++ b/tests/mkdir/restorecon.sh
@@ -0,0 +1,72 @@
+#!/bin/sh
+# test mkdir, mknod, mkfifo -Z
+
+# Copyright (C) 2013 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=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ mkdir
+require_selinux_
+
+
+get_selinux_type() { ls -Zd "$1" | sed -n 's/.*:\(.*_t\):.*/\1/p'; }
+
+mkdir subdir || framework_failure_
+chcon 'root:object_r:tmp_t:s0' subdir || framework_failure_
+cd subdir
+
+# --- mkdir -Z ---
+# Since in a tmp_t dir, dirs can be created as user_tmp_t ...
+mkdir standard || framework_failure_
+mkdir restored || framework_failure_
+if restorecon restored 2>/dev/null; then
+  # ... but when restored can be set to user_home_t
+  # So ensure the type for these mkdir -Z cases matches
+  # the directory type as set by restorecon.
+  mkdir -Z single || fail=1
+  # Run these as separate processes in case global context
+  # set for an arg, impacts on another arg
+  for dir in single_p single_p/existing multi/ple; do
+    mkdir -Zp "$dir" || fail=1
+  done
+  restored_type=$(get_selinux_type 'restored')
+  test "$(get_selinux_type 'single')" = "$restored_type" || fail=1
+  test "$(get_selinux_type 'single_p')" = "$restored_type" || fail=1
+  test "$(get_selinux_type 'single_p/existing')" = "$restored_type" || fail=1
+  test "$(get_selinux_type 'multi')" = "$restored_type" || fail=1
+  test "$(get_selinux_type 'multi/ple')" = "$restored_type" || fail=1
+fi
+if test "$fail" = '1'; then
+  ls -UZd standard restored
+  ls -UZd single single_p single_p/existing multi multi/ple
+fi
+
+# --- mknod -Z and mkfifo -Z ---
+# Assume if selinux present that we can create fifos
+for cmd_w_arg in 'mknod' 'mkfifo'; do
+  # In OpenBSD's /bin/sh, mknod is a shell built-in.
+  # Running via "env" ensures we run our program and not the built-in.
+  basename="$cmd_w_arg"
+  test "$basename" = 'mknod' && nt='p' || nt=''
+  env -- $cmd_w_arg $basename $nt || fail=1
+  env -- $cmd_w_arg ${basename}_restore $nt || fail=1
+  if restorecon ${basename}_restore 2>/dev/null; then
+    env -- $cmd_w_arg -Z ${basename}_Z $nt || fail=1
+    restored_type=$(get_selinux_type "${basename}_restore")
+    test "$(get_selinux_type ${basename}_Z)" = "$restored_type" || fail=1
+  fi
+done
+
+Exit $fail
diff --git a/tests/mkdir/selinux.sh b/tests/mkdir/selinux.sh
index e68f77b87..c1cfaf05e 100755
--- a/tests/mkdir/selinux.sh
+++ b/tests/mkdir/selinux.sh
@@ -32,7 +32,7 @@ msg="failed to set default file creation context to '$c':"
 for cmd_w_arg in 'mkdir dir' 'mknod b p' 'mkfifo f'; do
   # In OpenBSD's /bin/sh, mknod is a shell built-in.
   # Running via "env" ensures we run our program and not the built-in.
-  env -- $cmd_w_arg -Z $c 2> out && fail=1
+  env -- $cmd_w_arg --context=$c 2> out && fail=1
   set $cmd_w_arg; cmd=$1
   echo "$cmd: $msg" > exp || fail=1