[PATCH v3 4/4] crypto: add CRYPTO_TFM_REQ_IV_SERIALIZE flag

["Stephan Müller" <smueller@chronox.de>]

Crypto drivers may implement a streamlined serialization support for AIO
requests that is reported by the CRYPTO_ALG_SERIALIZES_IV_ACCESS flag to
the crypto user. When the user decides that he wants to send multiple
AIO requests concurrently and wants the crypto driver to handle the
serialization, the caller has to set CRYPTO_TFM_REQ_IV_SERIALIZE to notify
the crypto driver.

Only when this flag is enabled, the crypto driver shall apply its
serialization logic for handling IV updates between requests. If this
flag is not provided, the serialization logic shall not be applied by
the driver as the caller decides that it does not need it (because no
parallel AIO requests are sent) or that it performs its own
serialization.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
---
 crypto/algif_aead.c     | 15 ++++++++++++---
 crypto/algif_skcipher.c | 15 ++++++++++++---
 include/linux/crypto.h  |  1 +
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index 619147792cc9..5ec4dec6e6a1 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -66,13 +66,22 @@ static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 {
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
 	struct sock *psk = ask->parent;
 	struct alg_sock *pask = alg_sk(psk);
 	struct aead_tfm *aeadc = pask->private;
-	struct crypto_aead *tfm = aeadc->aead;
-	unsigned int ivsize = crypto_aead_ivsize(tfm);
+	struct crypto_aead *aead = aeadc->aead;
+	struct crypto_tfm *tfm = crypto_aead_tfm(aead);
+	unsigned int ivsize = crypto_aead_ivsize(aead);
+	int ret = af_alg_sendmsg(sock, msg, size, ivsize);
+
+	if (ret < 0)
+		return ret;
 
-	return af_alg_sendmsg(sock, msg, size, ivsize);
+	if (ctx->iiv == ALG_IV_SERIAL_PROCESSING)
+		tfm->crt_flags |= CRYPTO_TFM_REQ_IV_SERIALIZE;
+
+	return ret;
 }
 
 static int crypto_aead_copy_sgl(struct crypto_skcipher *null_tfm,
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index cf27dda6a181..fd2a0ba32feb 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -43,12 +43,21 @@ static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
 {
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
 	struct sock *psk = ask->parent;
 	struct alg_sock *pask = alg_sk(psk);
-	struct crypto_skcipher *tfm = pask->private;
-	unsigned ivsize = crypto_skcipher_ivsize(tfm);
+	struct crypto_skcipher *skc = pask->private;
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skc);
+	unsigned int ivsize = crypto_skcipher_ivsize(skc);
+	int ret = af_alg_sendmsg(sock, msg, size, ivsize);
+
+	if (ret < 0)
+		return ret;
 
-	return af_alg_sendmsg(sock, msg, size, ivsize);
+	if (ctx->iiv == ALG_IV_SERIAL_PROCESSING)
+		tfm->crt_flags |= CRYPTO_TFM_REQ_IV_SERIALIZE;
+
+	return ret;
 }
 
 static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 4860aa2c9be4..4d54f2b30692 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -133,6 +133,7 @@
 #define CRYPTO_TFM_REQ_WEAK_KEY		0x00000100
 #define CRYPTO_TFM_REQ_MAY_SLEEP	0x00000200
 #define CRYPTO_TFM_REQ_MAY_BACKLOG	0x00000400
+#define CRYPTO_TFM_REQ_IV_SERIALIZE	0x00000800
 #define CRYPTO_TFM_RES_WEAK_KEY		0x00100000
 #define CRYPTO_TFM_RES_BAD_KEY_LEN   	0x00200000
 #define CRYPTO_TFM_RES_BAD_KEY_SCHED 	0x00400000
-- 
2.14.3