ls: Add support for SELinux and a slightly modified -Z option.

I started with the patches from Red Hat.
The entries below tell how the code evolved.

* src/ls.c (print_long_format, print_file_name_and_frills): When
there is no security context (due to getfilecon/lgetfilecon failing
with e.g. ENOTSUP), print it as "?", not "".
* src/ls.c (print_file_name_and_frills): Make -Z work without -l.
(length_of_file_name_and_frills): Likewise.

* src/ls.c: Remove the --lcontext and --scontext options.
Change the way -Z, --context work so that it no longer implies -l.
Thus, -Z -l will work like -lcontext and -Z without -l will work
like --scontext.

Adjust tests to reflect new 'ls -l' syntax -- affects only
systems with SELinux when operating on a file with no ACL.
These tests assumed that everything before the first space on
each line is the 10-byte mode string.  But there may also be a "+"
in the 11th column, just before the space.  However, note that this
is not new.  The same thing would have happened even without the
change below, when listing a file with an ACL.
* tests/chmod/equals, tests/cp/cp-parents, tests/cp/fail-perm:
* tests/cp/link-preserve, tests/install/basic-1, tests/misc/mknod:
* tests/mkdir/parents, tests/mkdir/special-1, tests/mv/partition-perm:

Don't make compilation depend on USE_ACL.  An SELinux security
context counts as an "alternate access control method", so ls
must output a "+" for each file with a security context.
* src/ls.c [struct fileinfo] (have_acl): Declare unconditionally.
(FILE_HAS_ACL): Remove macro definition.  Use f->have_acl directly.
(gobble_file): Record whether a file has a security context, and
update the condition used to determine whether to print the "+".
(gobble_file): Call getfilecon/lgetfilecon also when
format == long_format, so that we get the "+".

* src/ls.c (gobble_file): Add a comment explaining why (with a
security context option) ls doesn't exit nonzero due to e.g.,
getfilecon failing with errno == ENOTSUP.

* src/ls.c (gobble_file): Ignore failure of getfilecon if it's due
to ENOTSUP.

* src/ls.c (gobble_file): Factor out three small blocks using
getfilecon and lgetfilecon.
Don't ignore return value from getfilecon and lgetfilecon.

* src/ls.c (print_long_format): Don't use ?: (empty 2nd arg with C
ternary operator).
(print_scontext_format): Likewise.
(print_scontext): Declare to be "bool", not int.  Adjust uses.

* src/Makefile.am (dir_LDADD, ls_LDADD, vdir_LDADD): Add $(LIB_SELINUX).

* tests/misc/chcon: New file.
* tests/misc/chcon-fail: New file.
* tests/Makefile.am (check-root): Run new, root-only misc/chcon test.
* tests/misc/Makefile.am (TESTS): Add chcon and chcon-fail.

* tests/misc/Makefile.am (TESTS): Add selinux.
* tests/misc/selinux: New file.
* tests/help-version: Skip chcon.

2 files changed, 8 insertions, 8 deletions

diff --git a/tests/mkdir/parents b/tests/mkdir/parents
index f0ead6ee8..d956e39d7 100755
--- a/tests/mkdir/parents
+++ b/tests/mkdir/parents
@@ -65,12 +65,12 @@ d_mode_arg=`"$abs_srcdir/../rwx-to-mode" $d_mode_str`
 mkdir -p -m $d_mode_arg a/b/c/d
 
 # Make sure the permissions of `a' haven't been changed.
-p=`ls -ld a|sed 's/ .*//'`; case $p in $mode_str);; *) fail=1;; esac
+p=`ls -ld a|cut -b-10`; case $p in $mode_str);; *) fail=1;; esac
 # `b's and `c's should reflect the umask
-p=`ls -ld a/b|sed 's/ .*//'`; case $p in drwx------);; *) fail=1;; esac
-p=`ls -ld a/b/c|sed 's/ .*//'`; case $p in drwx------);; *) fail=1;; esac
+p=`ls -ld a/b|cut -b-10`; case $p in drwx------);; *) fail=1;; esac
+p=`ls -ld a/b/c|cut -b-10`; case $p in drwx------);; *) fail=1;; esac
 
 # `d's perms are determined by the -m argument.
-p=`ls -ld a/b/c/d|sed 's/ .*//'`; case $p in $d_mode_str);; *) fail=1;; esac
+p=`ls -ld a/b/c/d|cut -b-10`; case $p in $d_mode_str);; *) fail=1;; esac
 
 (exit $fail); exit $fail
diff --git a/tests/mkdir/special-1 b/tests/mkdir/special-1
index a5b65043b..7f8dc7405 100755
--- a/tests/mkdir/special-1
+++ b/tests/mkdir/special-1
@@ -33,8 +33,8 @@ output_mode_string=drwxr-x-wT
 mkdir -m$set_mode_string $tmp || fail=1
 
 test -d $tmp || fail=1
-set -- `ls -ld $tmp`
-case "$1" in
+mode=`ls -ld $tmp|cut -b-10`
+case "$mode" in
   $output_mode_string) ;;
   *) fail=1 ;;
 esac
@@ -49,8 +49,8 @@ mkdir -m$set_mode_string $tmp2 2> /dev/null && fail=1
 mkdir --parents -m$set_mode_string $tmp2 || fail=1
 
 test -d $tmp2 || fail=1
-set -- `ls -ld $tmp2`
-case "$1" in
+mode=`ls -ld $tmp2|cut -b-10`
+case "$mode" in
   $output_mode_string) ;;
   *) fail=1 ;;
 esac