crypto: virtio - Register an algo only if it's supported

Register a crypto algo with the Linux crypto layer only if
the algorithm is supported by the backend virtio-crypto
device.

Also route crypto requests to a virtio-crypto
device, only if it can support the requested service and
algorithm.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Acked-by: Gonglei <arei.gonglei@huawei.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 76 insertions, 36 deletions

diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index af6a908dfa7a..7a104f636f11 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -49,12 +49,18 @@ struct virtio_crypto_sym_request {
 	bool encrypt;
 };
 
+struct virtio_crypto_algo {
+	uint32_t algonum;
+	uint32_t service;
+	unsigned int active_devs;
+	struct crypto_alg algo;
+};
+
 /*
  * The algs_lock protects the below global virtio_crypto_active_devs
  * and crypto algorithms registion.
  */
 static DEFINE_MUTEX(algs_lock);
-static unsigned int virtio_crypto_active_devs;
 static void virtio_crypto_ablkcipher_finalize_req(
 	struct virtio_crypto_sym_request *vc_sym_req,
 	struct ablkcipher_request *req,
@@ -312,15 +318,21 @@ static int virtio_crypto_ablkcipher_setkey(struct crypto_ablkcipher *tfm,
 					 unsigned int keylen)
 {
 	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+	uint32_t alg;
 	int ret;
 
+	ret = virtio_crypto_alg_validate_key(keylen, &alg);
+	if (ret)
+		return ret;
+
 	if (!ctx->vcrypto) {
 		/* New key */
 		int node = virtio_crypto_get_current_node();
 		struct virtio_crypto *vcrypto =
-				      virtcrypto_get_dev_node(node);
+				      virtcrypto_get_dev_node(node,
+				      VIRTIO_CRYPTO_SERVICE_CIPHER, alg);
 		if (!vcrypto) {
-			pr_err("virtio_crypto: Could not find a virtio device in the system\n");
+			pr_err("virtio_crypto: Could not find a virtio device in the system or unsupported algo\n");
 			return -ENODEV;
 		}
 
@@ -571,57 +583,85 @@ static void virtio_crypto_ablkcipher_finalize_req(
 	virtcrypto_clear_request(&vc_sym_req->base);
 }
 
-static struct crypto_alg virtio_crypto_algs[] = { {
-	.cra_name = "cbc(aes)",
-	.cra_driver_name = "virtio_crypto_aes_cbc",
-	.cra_priority = 150,
-	.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
-	.cra_blocksize = AES_BLOCK_SIZE,
-	.cra_ctxsize  = sizeof(struct virtio_crypto_ablkcipher_ctx),
-	.cra_alignmask = 0,
-	.cra_module = THIS_MODULE,
-	.cra_type = &crypto_ablkcipher_type,
-	.cra_init = virtio_crypto_ablkcipher_init,
-	.cra_exit = virtio_crypto_ablkcipher_exit,
-	.cra_u = {
-	   .ablkcipher = {
-			.setkey = virtio_crypto_ablkcipher_setkey,
-			.decrypt = virtio_crypto_ablkcipher_decrypt,
-			.encrypt = virtio_crypto_ablkcipher_encrypt,
-			.min_keysize = AES_MIN_KEY_SIZE,
-			.max_keysize = AES_MAX_KEY_SIZE,
-			.ivsize = AES_BLOCK_SIZE,
+static struct virtio_crypto_algo virtio_crypto_algs[] = { {
+	.algonum = VIRTIO_CRYPTO_CIPHER_AES_CBC,
+	.service = VIRTIO_CRYPTO_SERVICE_CIPHER,
+	.algo = {
+		.cra_name = "cbc(aes)",
+		.cra_driver_name = "virtio_crypto_aes_cbc",
+		.cra_priority = 150,
+		.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+		.cra_blocksize = AES_BLOCK_SIZE,
+		.cra_ctxsize  = sizeof(struct virtio_crypto_ablkcipher_ctx),
+		.cra_alignmask = 0,
+		.cra_module = THIS_MODULE,
+		.cra_type = &crypto_ablkcipher_type,
+		.cra_init = virtio_crypto_ablkcipher_init,
+		.cra_exit = virtio_crypto_ablkcipher_exit,
+		.cra_u = {
+			.ablkcipher = {
+				.setkey = virtio_crypto_ablkcipher_setkey,
+				.decrypt = virtio_crypto_ablkcipher_decrypt,
+				.encrypt = virtio_crypto_ablkcipher_encrypt,
+				.min_keysize = AES_MIN_KEY_SIZE,
+				.max_keysize = AES_MAX_KEY_SIZE,
+				.ivsize = AES_BLOCK_SIZE,
+			},
 		},
 	},
 } };
 
-int virtio_crypto_algs_register(void)
+int virtio_crypto_algs_register(struct virtio_crypto *vcrypto)
 {
 	int ret = 0;
+	int i = 0;
 
 	mutex_lock(&algs_lock);
-	if (++virtio_crypto_active_devs != 1)
-		goto unlock;
 
-	ret = crypto_register_algs(virtio_crypto_algs,
-			ARRAY_SIZE(virtio_crypto_algs));
-	if (ret)
-		virtio_crypto_active_devs--;
+	for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
+
+		uint32_t service = virtio_crypto_algs[i].service;
+		uint32_t algonum = virtio_crypto_algs[i].algonum;
+
+		if (!virtcrypto_algo_is_supported(vcrypto, service, algonum))
+			continue;
+
+		if (virtio_crypto_algs[i].active_devs == 0) {
+			ret = crypto_register_alg(&virtio_crypto_algs[i].algo);
+			if (ret)
+				goto unlock;
+		}
+
+		virtio_crypto_algs[i].active_devs++;
+		dev_info(&vcrypto->vdev->dev, "Registered algo %s\n",
+			 virtio_crypto_algs[i].algo.cra_name);
+	}
 
 unlock:
 	mutex_unlock(&algs_lock);
 	return ret;
 }
 
-void virtio_crypto_algs_unregister(void)
+void virtio_crypto_algs_unregister(struct virtio_crypto *vcrypto)
 {
+	int i = 0;
+
 	mutex_lock(&algs_lock);
-	if (--virtio_crypto_active_devs != 0)
-		goto unlock;
 
-	crypto_unregister_algs(virtio_crypto_algs,
-			ARRAY_SIZE(virtio_crypto_algs));
+	for (i = 0; i < ARRAY_SIZE(virtio_crypto_algs); i++) {
+
+		uint32_t service = virtio_crypto_algs[i].service;
+		uint32_t algonum = virtio_crypto_algs[i].algonum;
+
+		if (virtio_crypto_algs[i].active_devs == 0 ||
+		    !virtcrypto_algo_is_supported(vcrypto, service, algonum))
+			continue;
+
+		if (virtio_crypto_algs[i].active_devs == 1)
+			crypto_unregister_alg(&virtio_crypto_algs[i].algo);
+
+		virtio_crypto_algs[i].active_devs--;
+	}
 
-unlock:
 	mutex_unlock(&algs_lock);
 }