[PATCH] introduce audit rules counter

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/audit.h

@@ -410,6 +410,7 @@ static inline int audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 		return __audit_mq_getsetattr(mqdes, mqstat);
 	return 0;
 }
+extern int audit_n_rules;
 #else
 #define audit_alloc(t) ({ 0; })
 #define audit_free(t) do { ; } while (0)
@@ -437,6 +438,7 @@ static inline int audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 #define audit_mq_timedreceive(d,l,p,t) ({ 0; })
 #define audit_mq_notify(d,n) ({ 0; })
 #define audit_mq_getsetattr(d,s) ({ 0; })
+#define audit_n_rules 0
 #endif
 
 #ifdef CONFIG_AUDIT

kernel/auditfilter.c

@@ -1136,6 +1136,14 @@ static inline int audit_add_rule(struct audit_entry *entry,
 	struct audit_watch *watch = entry->rule.watch;
 	struct nameidata *ndp, *ndw;
 	int h, err, putnd_needed = 0;
+#ifdef CONFIG_AUDITSYSCALL
+	int dont_count = 0;
+
+	/* If either of these, don't count towards total */
+	if (entry->rule.listnr == AUDIT_FILTER_USER ||
+		entry->rule.listnr == AUDIT_FILTER_TYPE)
+		dont_count = 1;
+#endif
 
 	if (inode_f) {
 		h = audit_hash_ino(inode_f->val);
@@ -1176,6 +1184,10 @@ static inline int audit_add_rule(struct audit_entry *entry,
 	} else {
 		list_add_tail_rcu(&entry->list, list);
 	}
+#ifdef CONFIG_AUDITSYSCALL
+	if (!dont_count)
+		audit_n_rules++;
+#endif
 	mutex_unlock(&audit_filter_mutex);
 
 	if (putnd_needed)
@@ -1200,6 +1212,14 @@ static inline int audit_del_rule(struct audit_entry *entry,
 	struct audit_watch *watch, *tmp_watch = entry->rule.watch;
 	LIST_HEAD(inotify_list);
 	int h, ret = 0;
+#ifdef CONFIG_AUDITSYSCALL
+	int dont_count = 0;
+
+	/* If either of these, don't count towards total */
+	if (entry->rule.listnr == AUDIT_FILTER_USER ||
+		entry->rule.listnr == AUDIT_FILTER_TYPE)
+		dont_count = 1;
+#endif
 
 	if (inode_f) {
 		h = audit_hash_ino(inode_f->val);
@@ -1237,6 +1257,10 @@ static inline int audit_del_rule(struct audit_entry *entry,
 	list_del_rcu(&e->list);
 	call_rcu(&e->rcu, audit_free_rule_rcu);
 
+#ifdef CONFIG_AUDITSYSCALL
+	if (!dont_count)
+		audit_n_rules--;
+#endif
 	mutex_unlock(&audit_filter_mutex);
 
 	if (!list_empty(&inotify_list))

kernel/auditsc.c

@@ -85,6 +85,9 @@ extern int audit_enabled;
 /* Indicates that audit should log the full pathname. */
 #define AUDIT_NAME_FULL -1
 
+/* number of audit rules */
+int audit_n_rules;
+
 /* When fs/namei.c:getname() is called, we store the pointer in name and
  * we don't let putname() free it (instead we free all of the saved
  * pointers at syscall exit time).