crypto: hash - Add request chaining API

This adds request chaining to the ahash interface.  Request chaining
allows multiple requests to be submitted in one shot.  An algorithm
can elect to receive chained requests by setting the flag
CRYPTO_ALG_REQ_CHAIN.  If this bit is not set, the API will break
up chained requests and submit them one-by-one.

A new err field is added to struct crypto_async_request to record
the return value for each individual request.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

4 files changed, 63 insertions, 10 deletions

diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index 156de41ca760..11065978d360 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -11,6 +11,7 @@
 #include <linux/align.h>
 #include <linux/cache.h>
 #include <linux/crypto.h>
+#include <linux/list.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
 
@@ -271,4 +272,14 @@ static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 	return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 }
 
+static inline bool crypto_request_chained(struct crypto_async_request *req)
+{
+	return !list_empty(&req->list);
+}
+
+static inline bool crypto_tfm_req_chain(struct crypto_tfm *tfm)
+{
+	return tfm->__crt_alg->cra_flags & CRYPTO_ALG_REQ_CHAIN;
+}
+
 #endif	/* _CRYPTO_ALGAPI_H */
diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index 9c1f8ca59a77..0a6f744ce4a1 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -572,16 +572,7 @@ static inline struct ahash_request *ahash_request_alloc_noprof(
  * ahash_request_free() - zeroize and free the request data structure
  * @req: request data structure cipher handle to be freed
  */
-static inline void ahash_request_free(struct ahash_request *req)
-{
-	kfree_sensitive(req);
-}
-
-static inline void ahash_request_zero(struct ahash_request *req)
-{
-	memzero_explicit(req, sizeof(*req) +
-			      crypto_ahash_reqsize(crypto_ahash_reqtfm(req)));
-}
+void ahash_request_free(struct ahash_request *req);
 
 static inline struct ahash_request *ahash_request_cast(
 	struct crypto_async_request *req)
@@ -622,6 +613,7 @@ static inline void ahash_request_set_callback(struct ahash_request *req,
 	req->base.complete = compl;
 	req->base.data = data;
 	req->base.flags = flags;
+	crypto_reqchain_init(&req->base);
 }
 
 /**
@@ -646,6 +638,12 @@ static inline void ahash_request_set_crypt(struct ahash_request *req,
 	req->result = result;
 }
 
+static inline void ahash_request_chain(struct ahash_request *req,
+				       struct ahash_request *head)
+{
+	crypto_request_chain(&req->base, &head->base);
+}
+
 /**
  * DOC: Synchronous Message Digest API
  *
@@ -947,4 +945,14 @@ static inline void shash_desc_zero(struct shash_desc *desc)
 			 sizeof(*desc) + crypto_shash_descsize(desc->tfm));
 }
 
+static inline int ahash_request_err(struct ahash_request *req)
+{
+	return req->base.err;
+}
+
+static inline bool ahash_is_async(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_is_async(&tfm->base);
+}
+
 #endif	/* _CRYPTO_HASH_H */
diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h
index 84da3424decc..36425ecd2c37 100644
--- a/include/crypto/internal/hash.h
+++ b/include/crypto/internal/hash.h
@@ -247,5 +247,15 @@ static inline struct crypto_shash *__crypto_shash_cast(struct crypto_tfm *tfm)
 	return container_of(tfm, struct crypto_shash, base);
 }
 
+static inline bool ahash_request_chained(struct ahash_request *req)
+{
+	return crypto_request_chained(&req->base);
+}
+
+static inline bool crypto_ahash_req_chain(struct crypto_ahash *tfm)
+{
+	return crypto_tfm_req_chain(&tfm->base);
+}
+
 #endif	/* _CRYPTO_INTERNAL_HASH_H */
 
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index b164da5e129e..1d2a6c515d58 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -13,6 +13,8 @@
 #define _LINUX_CRYPTO_H
 
 #include <linux/completion.h>
+#include <linux/errno.h>
+#include <linux/list.h>
 #include <linux/refcount.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -124,6 +126,9 @@
  */
 #define CRYPTO_ALG_FIPS_INTERNAL	0x00020000
 
+/* Set if the algorithm supports request chains. */
+#define CRYPTO_ALG_REQ_CHAIN		0x00040000
+
 /*
  * Transform masks and values (for crt_flags).
  */
@@ -174,6 +179,7 @@ struct crypto_async_request {
 	struct crypto_tfm *tfm;
 
 	u32 flags;
+	int err;
 };
 
 /**
@@ -540,5 +546,23 @@ int crypto_comp_decompress(struct crypto_comp *tfm,
 			   const u8 *src, unsigned int slen,
 			   u8 *dst, unsigned int *dlen);
 
+static inline void crypto_reqchain_init(struct crypto_async_request *req)
+{
+	req->err = -EINPROGRESS;
+	INIT_LIST_HEAD(&req->list);
+}
+
+static inline void crypto_request_chain(struct crypto_async_request *req,
+					struct crypto_async_request *head)
+{
+	req->err = -EINPROGRESS;
+	list_add_tail(&req->list, &head->list);
+}
+
+static inline bool crypto_tfm_is_async(struct crypto_tfm *tfm)
+{
+	return tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC;
+}
+
 #endif	/* _LINUX_CRYPTO_H */