crypto: api - Add crypto_attr_alg2 helper

This patch adds the helper crypto_attr_alg2 which is similar to
crypto_attr_alg but takes an extra frontend argument.  This is
intended to be used by new style algorithm types such as shash.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/algapi.c

@@ -644,7 +644,9 @@ const char *crypto_attr_alg_name(struct rtattr *rta)
 }
 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
 
-struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
+struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
+				    const struct crypto_type *frontend,
+				    u32 type, u32 mask)
 {
 	const char *name;
 	int err;
@@ -654,9 +656,9 @@ struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 	if (IS_ERR(name))
 		return ERR_PTR(err);
 
-	return crypto_alg_mod_lookup(name, type, mask);
+	return crypto_find_alg(name, frontend, type, mask);
 }
-EXPORT_SYMBOL_GPL(crypto_attr_alg);
+EXPORT_SYMBOL_GPL(crypto_attr_alg2);
 
 int crypto_attr_u32(struct rtattr *rta, u32 *num)
 {

crypto/api.c

@@ -503,6 +503,27 @@ void *crypto_create_tfm(struct crypto_alg *alg,
 }
 EXPORT_SYMBOL_GPL(crypto_create_tfm);
 
+struct crypto_alg *crypto_find_alg(const char *alg_name,
+				   const struct crypto_type *frontend,
+				   u32 type, u32 mask)
+{
+	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) =
+		crypto_alg_mod_lookup;
+
+	if (frontend) {
+		type &= frontend->maskclear;
+		mask &= frontend->maskclear;
+		type |= frontend->type;
+		mask |= frontend->maskset;
+
+		if (frontend->lookup)
+			lookup = frontend->lookup;
+	}
+
+	return lookup(alg_name, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_find_alg);
+
 /*
  *	crypto_alloc_tfm - Locate algorithm and allocate transform
  *	@alg_name: Name of algorithm
@@ -526,21 +547,13 @@ EXPORT_SYMBOL_GPL(crypto_create_tfm);
 void *crypto_alloc_tfm(const char *alg_name,
 		       const struct crypto_type *frontend, u32 type, u32 mask)
 {
-	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask);
 	void *tfm;
 	int err;
 
-	type &= frontend->maskclear;
-	mask &= frontend->maskclear;
-	type |= frontend->type;
-	mask |= frontend->maskset;
-
-	lookup = frontend->lookup ?: crypto_alg_mod_lookup;
-
 	for (;;) {
 		struct crypto_alg *alg;
 
-		alg = lookup(alg_name, type, mask);
+		alg = crypto_find_alg(alg_name, frontend, type, mask);
 		if (IS_ERR(alg)) {
 			err = PTR_ERR(alg);
 			goto err;

crypto/internal.h

@@ -106,6 +106,9 @@ struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
 				      u32 mask);
 void *crypto_create_tfm(struct crypto_alg *alg,
 			const struct crypto_type *frontend);
+struct crypto_alg *crypto_find_alg(const char *alg_name,
+				   const struct crypto_type *frontend,
+				   u32 type, u32 mask);
 void *crypto_alloc_tfm(const char *alg_name,
 		       const struct crypto_type *frontend, u32 type, u32 mask);
 

include/crypto/algapi.h

@@ -136,7 +136,16 @@ static inline void crypto_set_spawn(struct crypto_spawn *spawn,
 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb);
 int crypto_check_attr_type(struct rtattr **tb, u32 type);
 const char *crypto_attr_alg_name(struct rtattr *rta);
-struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask);
+struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
+				    const struct crypto_type *frontend,
+				    u32 type, u32 mask);
+
+static inline struct crypto_alg *crypto_attr_alg(struct rtattr *rta,
+						 u32 type, u32 mask)
+{
+	return crypto_attr_alg2(rta, NULL, type, mask);
+}
+
 int crypto_attr_u32(struct rtattr *rta, u32 *num);
 void *crypto_alloc_instance2(const char *name, struct crypto_alg *alg,
 			     unsigned int head);