selinux: drop avtab_search()

avtab_search() shares the same logic with avtab_search_node(), except
that it returns, if found, a pointer to the struct avtab_node member
datum instead of the node itself.  Since the member is an embedded
struct, and not a pointer, the returned value of avtab_search() and
avtab_search_node() will always in unison either be NULL or non-NULL.

Drop avtab_search() and replace its calls by avtab_search_node() to
deduplicate logic and adopt the only caller caring for the type of
the returned value accordingly.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

4 files changed, 8 insertions, 42 deletions

diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
index 8d7c14ca27a2..5fd439c5b8a4 100644
--- a/security/selinux/ss/avtab.c
+++ b/security/selinux/ss/avtab.c
@@ -180,38 +180,6 @@ struct avtab_node *avtab_insert_nonunique(struct avtab *h,
 	return avtab_insert_node(h, hvalue, prev, key, datum);
 }
 
-struct avtab_datum *avtab_search(struct avtab *h, const struct avtab_key *key)
-{
-	int hvalue;
-	struct avtab_node *cur;
-	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
-
-	if (!h || !h->nslot)
-		return NULL;
-
-	hvalue = avtab_hash(key, h->mask);
-	for (cur = h->htable[hvalue]; cur;
-	     cur = cur->next) {
-		if (key->source_type == cur->key.source_type &&
-		    key->target_type == cur->key.target_type &&
-		    key->target_class == cur->key.target_class &&
-		    (specified & cur->key.specified))
-			return &cur->datum;
-
-		if (key->source_type < cur->key.source_type)
-			break;
-		if (key->source_type == cur->key.source_type &&
-		    key->target_type < cur->key.target_type)
-			break;
-		if (key->source_type == cur->key.source_type &&
-		    key->target_type == cur->key.target_type &&
-		    key->target_class < cur->key.target_class)
-			break;
-	}
-
-	return NULL;
-}
-
 /* This search function returns a node pointer, and can be used in
  * conjunction with avtab_search_next_node()
  */
diff --git a/security/selinux/ss/avtab.h b/security/selinux/ss/avtab.h
index f265e9da18e2..c2b88430c916 100644
--- a/security/selinux/ss/avtab.h
+++ b/security/selinux/ss/avtab.h
@@ -90,7 +90,6 @@ struct avtab {
 void avtab_init(struct avtab *h);
 int avtab_alloc(struct avtab *, u32);
 int avtab_alloc_dup(struct avtab *new, const struct avtab *orig);
-struct avtab_datum *avtab_search(struct avtab *h, const struct avtab_key *k);
 void avtab_destroy(struct avtab *h);
 void avtab_hash_eval(struct avtab *h, const char *tag);
 
diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c
index b156c181c3c1..81ff676f209a 100644
--- a/security/selinux/ss/conditional.c
+++ b/security/selinux/ss/conditional.c
@@ -272,7 +272,7 @@ static int cond_insertf(struct avtab *a, const struct avtab_key *k,
 	 * cond_te_avtab.
 	 */
 	if (k->specified & AVTAB_TYPE) {
-		if (avtab_search(&p->te_avtab, k)) {
+		if (avtab_search_node(&p->te_avtab, k)) {
 			pr_err("SELinux: type rule already exists outside of a conditional.\n");
 			return -EINVAL;
 		}
@@ -304,7 +304,7 @@ static int cond_insertf(struct avtab *a, const struct avtab_key *k,
 				}
 			}
 		} else {
-			if (avtab_search(&p->te_cond_avtab, k)) {
+			if (avtab_search_node(&p->te_cond_avtab, k)) {
 				pr_err("SELinux: conflicting type rules when adding type rule for true.\n");
 				return -EINVAL;
 			}
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 83b85536cd2b..fa47e4e38935 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1706,8 +1706,7 @@ static int security_compute_sid(u32 ssid,
 	struct context *scontext, *tcontext, newcontext;
 	struct sidtab_entry *sentry, *tentry;
 	struct avtab_key avkey;
-	struct avtab_datum *avdatum;
-	struct avtab_node *node;
+	struct avtab_node *avnode, *node;
 	u16 tclass;
 	int rc = 0;
 	bool sock;
@@ -1815,22 +1814,22 @@ retry:
 	avkey.target_type = tcontext->type;
 	avkey.target_class = tclass;
 	avkey.specified = specified;
-	avdatum = avtab_search(&policydb->te_avtab, &avkey);
+	avnode = avtab_search_node(&policydb->te_avtab, &avkey);
 
 	/* If no permanent rule, also check for enabled conditional rules */
-	if (!avdatum) {
+	if (!avnode) {
 		node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
 		for (; node; node = avtab_search_node_next(node, specified)) {
 			if (node->key.specified & AVTAB_ENABLED) {
-				avdatum = &node->datum;
+				avnode = node;
 				break;
 			}
 		}
 	}
 
-	if (avdatum) {
+	if (avnode) {
 		/* Use the type from the type transition/member/change rule. */
-		newcontext.type = avdatum->u.data;
+		newcontext.type = avnode->datum.u.data;
 	}
 
 	/* if we have a objname this is a file trans check so check those rules */