maint: refactor SMACK interface to a separate module

Consolidate all smack routines and checks in a module.
We replace and wrap the most commonly used smack routines,
which allows removing ifdefs throughout the code.

* gl/lib/smack.h: A new header containing the implementation
of the wrapped and replacement routines.  Note the is_smack_enabled()
routine should be optimized out at compile time when compiled
on a system without libsmack.
* gl/modules/smack: Describe the new module and move the
configure time code here from ...
* m4/jm-macros.m4: ... here.
* bootstrap.conf: Reference the new module.
* src/id.c: Use the routines without ifdefs where possible.
* src/ls.c: Likewise.
* src/mkdir.c: Likewise.
* src/mkfifo.c: Likewise.
* src/mknod.c: Likewise.

5 files changed, 16 insertions, 45 deletions

diff --git a/src/id.c b/src/id.c
index b7384a7cb..3e7016f7b 100644
--- a/src/id.c
+++ b/src/id.c
@@ -24,15 +24,13 @@
 #include <grp.h>
 #include <getopt.h>
 #include <selinux/selinux.h>
-#ifdef HAVE_SMACK
-# include <sys/smack.h>
-#endif
 
 #include "system.h"
 #include "error.h"
 #include "mgetgroups.h"
 #include "quote.h"
 #include "group-list.h"
+#include "smack.h"
 
 /* The official name of this program (e.g., no 'g' prefix).  */
 #define PROGRAM_NAME "id"
@@ -110,9 +108,7 @@ main (int argc, char **argv)
 {
   int optc;
   int selinux_enabled = (is_selinux_enabled () > 0);
-#ifdef HAVE_SMACK
-  int smack_enabled = (smack_smackfs_path () != NULL);
-#endif
+  bool smack_enabled = is_smack_enabled ();
 
   /* If true, output the list of all group IDs. -G */
   bool just_group_list = false;
@@ -207,14 +203,11 @@ main (int argc, char **argv)
           || (default_format && ! getenv ("POSIXLY_CORRECT"))))
     {
       /* Report failure only if --context (-Z) was explicitly requested.  */
-      if (selinux_enabled && getcon (&context) && just_context)
+      if ((selinux_enabled && getcon (&context) && just_context)
+          || (smack_enabled
+              && smack_new_label_from_self ((char **) &context) < 0
+              && just_context))
         error (EXIT_FAILURE, 0, _("can't get process context"));
-#ifdef HAVE_SMACK
-      else if (smack_enabled
-               && smack_new_label_from_self ((char **) &context) < 0
-               && just_context)
-        error (EXIT_FAILURE, 0, _("can't get process context"));
-#endif
     }
 
   if (n_ids == 1)
diff --git a/src/ls.c b/src/ls.c
index 61324c3f4..e341c6799 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -101,6 +101,7 @@
 #include "obstack.h"
 #include "quote.h"
 #include "quotearg.h"
+#include "smack.h"
 #include "stat-size.h"
 #include "stat-time.h"
 #include "strftime.h"
@@ -115,10 +116,6 @@
 # include <sys/capability.h>
 #endif
 
-#ifdef HAVE_SMACK
-# include <sys/smack.h>
-#endif
-
 #define PROGRAM_NAME (ls_mode == LS_LS ? "ls" \
                       : (ls_mode == LS_MULTI_COL \
                          ? "dir" : "vdir"))
@@ -2762,11 +2759,9 @@ free_ent (struct fileinfo *f)
   free (f->linkname);
   if (f->scontext != UNKNOWN_SECURITY_CONTEXT)
     {
-#ifdef HAVE_SMACK
-      if (smack_smackfs_path ())
+      if (is_smack_enabled ())
         free (f->scontext);
       else
-#endif
         freecon (f->scontext);
     }
 }
@@ -2825,7 +2820,7 @@ getfilecon_cache (char const *file, struct fileinfo *f, bool deref)
     }
   int r = 0;
 #ifdef HAVE_SMACK
-  if (smack_smackfs_path ())
+  if (is_smack_enabled ())
     r = smack_new_label_from_path (file, "security.SMACK64", deref,
                                    &f->scontext);
   else
@@ -3030,11 +3025,9 @@ gobble_file (char const *name, enum filetype type, ino_t inode,
 
           if (err == 0)
             {
-#ifdef HAVE_SMACK
-              if (smack_smackfs_path ())
+              if (is_smack_enabled ())
                 have_scontext = ! STREQ ("_", f->scontext);
               else
-#endif
                 have_scontext = ! STREQ ("unlabeled", f->scontext);
             }
           else
diff --git a/src/mkdir.c b/src/mkdir.c
index e56b6cbbd..479faca85 100644
--- a/src/mkdir.c
+++ b/src/mkdir.c
@@ -22,10 +22,6 @@
 #include <sys/types.h>
 #include <selinux/selinux.h>
 
-#ifdef HAVE_SMACK
-# include <sys/smack.h>
-#endif
-
 #include "system.h"
 #include "error.h"
 #include "mkdir-p.h"
@@ -33,6 +29,7 @@
 #include "prog-fprintf.h"
 #include "quote.h"
 #include "savewd.h"
+#include "smack.h"
 
 /* The official name of this program (e.g., no 'g' prefix).  */
 #define PROGRAM_NAME "mkdir"
@@ -201,11 +198,9 @@ main (int argc, char **argv)
 
   if (scontext)
     {
-#ifdef HAVE_SMACK
-      if (smack_smackfs_path ())
+      if (is_smack_enabled ())
         ret = smack_set_label_for_self (scontext);
       else
-#endif
         ret = setfscreatecon (scontext);
     }
 
diff --git a/src/mkfifo.c b/src/mkfifo.c
index a87a393e2..f9fcc0a60 100644
--- a/src/mkfifo.c
+++ b/src/mkfifo.c
@@ -22,14 +22,11 @@
 #include <sys/types.h>
 #include <selinux/selinux.h>
 
-#ifdef HAVE_SMACK
-# include <sys/smack.h>
-#endif
-
 #include "system.h"
 #include "error.h"
 #include "modechange.h"
 #include "quote.h"
+#include "smack.h"
 
 /* The official name of this program (e.g., no 'g' prefix).  */
 #define PROGRAM_NAME "mkfifo"
@@ -115,11 +112,9 @@ main (int argc, char **argv)
 
   if (scontext)
     {
-#ifdef HAVE_SMACK
-      if (smack_smackfs_path ())
+      if (is_smack_enabled ())
         ret = smack_set_label_for_self (scontext);
       else
-#endif
         ret = setfscreatecon (scontext);
     }
 
diff --git a/src/mknod.c b/src/mknod.c
index 9f0afb3ff..4fd6ed0f4 100644
--- a/src/mknod.c
+++ b/src/mknod.c
@@ -22,14 +22,11 @@
 #include <sys/types.h>
 #include <selinux/selinux.h>
 
-#ifdef HAVE_SMACK
-# include <sys/smack.h>
-#endif
-
 #include "system.h"
 #include "error.h"
 #include "modechange.h"
 #include "quote.h"
+#include "smack.h"
 #include "xstrtol.h"
 
 /* The official name of this program (e.g., no 'g' prefix).  */
@@ -171,11 +168,9 @@ main (int argc, char **argv)
 
   if (scontext)
     {
-#ifdef HAVE_SMACK
-      if (smack_smackfs_path ())
+      if (is_smack_enabled ())
         ret = smack_set_label_for_self (scontext);
       else
-#endif
         ret = setfscreatecon (scontext);
     }