New API: yara_destroy

The yara_destroy API allows to claim resources back via the removal of
the previously loaded Yara rules.

Signed-off-by: Matteo Cafasso <noxdafox@gmail.com>

daemon/yara.c

@@ -111,6 +111,20 @@ do_yara_load (void)
   return (r == ERROR_SUCCESS) ? 0 : -1;
 }
 
+int
+do_yara_destroy (void)
+{
+  if (rules == NULL) {
+    reply_with_error ("no yara rules loaded");
+    return -1;
+  }
+
+  yr_rules_destroy (rules);
+  rules = NULL;
+
+  return 0;
+}
+
 /* Compile source code rules and load them.
  * Return ERROR_SUCCESS on success, Yara error code type on error.
  */

generator/actions_yara.ml

@@ -45,4 +45,12 @@ it is recommended to compile them first.
 
 Previously loaded rules will be destroyed." };
 
+  { defaults with
+    name = "yara_destroy"; added = (1, 37, 13);
+    style = RErr, [], [];
+    optional = Some "libyara";
+    shortdesc = "destroy previously loaded yara rules";
+    longdesc = "\
+Destroy previously loaded Yara rules in order to free libguestfs resources." };
+
 ]

generator/proc_nr.ml

@@ -480,6 +480,7 @@ let proc_nr = [
 470, "internal_find_inode";
 471, "mksquashfs";
 472, "yara_load";
+473, "yara_destroy";
 ]
 
 (* End of list.  If adding a new entry, add it at the end of the list

lib/MAX_PROC_NR

@@ -1 +1 @@
-472
+473