maint: fix const correctness warnings with security_context_t

The security_context_t type was always an artificial separation
from a standard char* string, and various libselinux using code
assumed both were synonymous.  In addition, prior to libselinux 2.3
function declarations were incorrect wrt constness of this type.
Here we replace security_context_t with char*, and also
provide a wrapper function to cater for the const issue on
older libselinux.

* src/system.h (se_const): A new function to avoid and identify
the const issue on older libselinux.
* src/copy.c: s/security_context_t/char */.
* src/cp.c: Likewise.
* src/id.c: Likewise.
* src/install.c: Likewise.
* src/ls.c: Likewise.
* src/mkdir.c: Likewise.
* src/mkfifo.c: Likewise.
* src/mknod.c: Likewise.
* src/runcon.c: Likewise.
* src/selinux.c: Likewise.
* tests/cp/no-ctx.sh: Likewise.
* src/chcon.c: Likesize.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/system.h b/src/system.h
index f295ad1c2..162446c11 100644
--- a/src/system.h
+++ b/src/system.h
@@ -657,3 +657,9 @@ stzncpy (char *restrict dest, char const *restrict src, size_t len)
 #ifndef ARRAY_CARDINALITY
 # define ARRAY_CARDINALITY(Array) (sizeof (Array) / sizeof *(Array))
 #endif
+
+/* Avoid const warnings by casting to more portable type.
+   This is to cater for the incorrect const function declarations
+   in selinux.h before libselinux-2.3 (May 2014).
+   When version >= 2.3 is ubiquitous remove this function.  */
+static inline char * se_const (char const * sctx) { return (char *) sctx; }