[RFC PATCH crypto -v3 1/2] AES-NI: Add support to access underlying blkcipher under cryptd ablkcipher

[RFC PATCH crypto -v3 1/2] AES-NI: Add support to access underlying blkcipher under cryptd ablkcipher

[Huang Ying]

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cryptd_alloc_ablkcipher() will allocate a cryptd-ed ablkcipher for
specified algorithm name. The new allocated one is guaranteed to be
cryptd-ed ablkcipher, so the blkcipher underlying can be gotten via
cryptd_ablkcipher_child().

Signed-off-by: Huang Ying <ying.huang@intel.com>

---
 crypto/cryptd.c         |   19 +++++++++++++++++++
 include/crypto/algapi.h |    5 +++++
 2 files changed, 24 insertions(+)

--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -537,6 +537,25 @@ static struct crypto_template cryptd_tmp
 	.module = THIS_MODULE,
 };
 
+struct crypto_ablkcipher *cryptd_alloc_ablkcipher(const char *alg_name,
+						  u32 type, u32 mask)
+{
+	char cryptd_alg_name[CRYPTO_MAX_ALG_NAME];
+
+	if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
+		     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
+		return ERR_PTR(-EINVAL);
+	return crypto_alloc_ablkcipher(cryptd_alg_name, type, mask);
+}
+EXPORT_SYMBOL_GPL(cryptd_alloc_ablkcipher);
+
+struct crypto_blkcipher *cryptd_ablkcipher_child(struct crypto_ablkcipher *tfm)
+{
+	struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+	return ctx->child;
+}
+EXPORT_SYMBOL_GPL(cryptd_ablkcipher_child);
+
 static inline int cryptd_create_thread(struct cryptd_state *state,
 				       int (*fn)(void *data), const char *name)
 {
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -145,6 +145,11 @@ int blkcipher_walk_virt_block(struct blk
 			      struct blkcipher_walk *walk,
 			      unsigned int blocksize);
 
+/* alg_name should be algorithm to be cryptd-ed */
+struct crypto_ablkcipher *cryptd_alloc_ablkcipher(const char *alg_name,
+						  u32 type, u32 mask);
+struct crypto_blkcipher *cryptd_ablkcipher_child(struct crypto_ablkcipher *tfm);
+
 static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm)
 {
 	unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);


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Re: [RFC PATCH crypto -v3 1/2] AES-NI: Add support to access underlying blkcipher under cryptd ablkcipher

[Herbert Xu]

On Wed, Jan 14, 2009 at 03:44:06PM +0800, Huang Ying wrote:
> cryptd_alloc_ablkcipher() will allocate a cryptd-ed ablkcipher for
> specified algorithm name. The new allocated one is guaranteed to be
> cryptd-ed ablkcipher, so the blkcipher underlying can be gotten via
> cryptd_ablkcipher_child().
> 
> Signed-off-by: Huang Ying <ying.huang@intel.com>

Thanks for the patch!
  
> +struct crypto_ablkcipher *cryptd_alloc_ablkcipher(const char *alg_name,
> +						  u32 type, u32 mask)

It should have its own type so that we get compiler type checking.
Something like,

	struct cryptd_ablkcipher {
		struct crypto_ablkcipher *cipher;
	};

> +	if (snprintf(cryptd_alg_name, CRYPTO_MAX_ALG_NAME,
> +		     "cryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
> +		return ERR_PTR(-EINVAL);
> +	return crypto_alloc_ablkcipher(cryptd_alg_name, type, mask);

We should also check that the new tfm's module matches ours, i.e.,

	crypto_ablkcipher_tfm(cipher)->__crt_alg->cra_module ==
	THIS_MODULE

Granted this doesn't do much if we're built-in but it's better
than nothing.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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