[PATCH 02/15] crypto: algif_skcipher - Add support for tailsize

[Herbert Xu <herbert@gondor.apana.org.au>]

This patch makes use of the new tailsize attribute so that algorithms
such as CTS can be supported properly when a request it too large to
be processed in one go.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
 crypto/algif_skcipher.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 02cea2149504..e22516c3d285 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -103,13 +103,14 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 	struct af_alg_ctx *ctx = ask->private;
 	struct crypto_skcipher *tfm = pask->private;
 	unsigned int bs = crypto_skcipher_chunksize(tfm);
+	unsigned int ts = crypto_skcipher_tailsize(tfm);
 	struct af_alg_async_req *areq;
 	unsigned cflags = 0;
 	int err = 0;
 	size_t len = 0;
 
-	if (!ctx->init || (ctx->more && ctx->used < bs)) {
-		err = af_alg_wait_for_data(sk, flags, bs);
+	if (!ctx->init || (ctx->more && ctx->used < bs + ts)) {
+		err = af_alg_wait_for_data(sk, flags, bs + ts);
 		if (err)
 			return err;
 	}
@@ -130,6 +131,8 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 	 * full block size buffers.
 	 */
 	if (ctx->more || len < ctx->used) {
+		if (ctx->more && ctx->used - ts < len)
+			len = ctx->used - ts;
 		len -= len % bs;
 		cflags |= CRYPTO_SKCIPHER_REQ_NOTFINAL;
 	}
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt