add exerimental deny flag in the tables

For now, perm table does not set the thrid parameter to anything useful

src/temp_permissions_table.h

@@ -2,6 +2,7 @@
 #ifndef TEMP_PERMISSIONS_TABLE_H
 #define TEMP_PERMISSIONS_TABLE_H
 
+#include "access_t.h"
 #include "process_info.h"
 
 /**
@@ -9,31 +10,43 @@
  *
  * @return: 0 on success, -1 on failure (e.g. ENOMEM)
  */
-int init_temp_permissions_table();
+int init_temp_permissions_table(void);
 
 /**
  * Destroys the temporary permissions table.
  *
- * @note: the table is guranteed to be destroyed if it is already initialized
+ * @note: the table is guranteed to be destroyed if it is already initialized.
+ * It does not indicate any errors whatsoever. If something goes wrong - you are
+ * screwed.
  */
-void destroy_temp_permissions_table();
+void destroy_temp_permissions_table(void);
 
 /**
- * Checks if the process has a temporary access to the file.
+ * Checks if the process or any of it's parents have temporary access to the
+ * file.
+ *
+ * @param filename: The file that the process is trying to access
+ * @pram pi: The process information
+ * @return: access status - ALLOW, DENY or NDEF in case if no information was
+ * found. Does not return ALLOW_TEMP.
+ * @note: In case one of the parent processes is killed while this function
+ * execution the result is not guranteed to be correct. It should only lead to
+ * false negatives, though.
+ */
+access_t check_temp_access(const char *filename, struct process_info pi);
+
+typedef enum { SET_DENY, SET_ALLOW } set_mode_t;
+
+/**
+ * Sets temporary access mode of the process to the file.
  *
  * @param filename: The file that the process is trying to access
  * @param pi: The process information
- * @return: 0 if access is denied, 1 if access is allowed
+ * @param mode: Kind of access rule to be set - SET_DENY to deny access, and
+ * SET_ALLOW to allow access.
+ * @return: 0 on success, -1 on failure.
  */
-int check_temp_access(const char *filename, struct process_info pi);
-
-/**
- * Gives temporary access to the process to the file.
- *
- * @param filename: The file that the process is trying to access
- * @param pi: The process information
- * @return: 0 on success, -1 on failure (e.g. ENOMEM)
- */
-int give_temp_access(const char *filename, struct process_info pi);
+int set_temp_access(const char *filename, struct process_info pi,
+                    set_mode_t mode);
 
 #endif // !TEMP_PERMISSIONS_TABLE_H