[dpdk-dev] [PATCH 5/8] crypto/snow3g: do not append digest

[Pablo de Lara <pablo.de.lara.guarch@intel.com>]

When performing an authentication verification,
the PMD was using memory at the end of the input buffer,
to store temporarily the digest.
This operation requires the buffer to have enough
tailroom unnecessarily.
Instead, memory is allocated for each queue pair, to store
temporarily the digest generated by the driver, so it can
be compared with the one provided in the crypto operation,
without needing to touch the input buffer.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---
 drivers/crypto/snow3g/rte_snow3g_pmd.c         | 22 ++++++++--------------
 drivers/crypto/snow3g/rte_snow3g_pmd_private.h |  7 +++++++
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/crypto/snow3g/rte_snow3g_pmd.c b/drivers/crypto/snow3g/rte_snow3g_pmd.c
index dad4506..2083699 100644
--- a/drivers/crypto/snow3g/rte_snow3g_pmd.c
+++ b/drivers/crypto/snow3g/rte_snow3g_pmd.c
@@ -43,7 +43,6 @@
 #include "rte_snow3g_pmd_private.h"
 
 #define SNOW3G_IV_LENGTH 16
-#define SNOW3G_DIGEST_LENGTH 4
 #define SNOW3G_MAX_BURST 8
 #define BYTE_LEN 8
 
@@ -263,7 +262,7 @@ process_snow3g_cipher_op_bit(struct rte_crypto_op *op,
 
 /** Generate/verify hash from mbufs with same hash key. */
 static int
-process_snow3g_hash_op(struct rte_crypto_op **ops,
+process_snow3g_hash_op(struct snow3g_qp *qp, struct rte_crypto_op **ops,
 		struct snow3g_session *session,
 		uint8_t num_ops)
 {
@@ -289,8 +288,7 @@ process_snow3g_hash_op(struct rte_crypto_op **ops,
 				session->auth_iv_offset);
 
 		if (session->auth_op == RTE_CRYPTO_AUTH_OP_VERIFY) {
-			dst = (uint8_t *)rte_pktmbuf_append(ops[i]->sym->m_src,
-					SNOW3G_DIGEST_LENGTH);
+			dst = (uint8_t *)&qp->temp_digest;
 
 			sso_snow3g_f9_1_buffer(&session->pKeySched_hash,
 					iv, src,
@@ -299,10 +297,6 @@ process_snow3g_hash_op(struct rte_crypto_op **ops,
 			if (memcmp(dst, ops[i]->sym->auth.digest.data,
 					SNOW3G_DIGEST_LENGTH) != 0)
 				ops[i]->status = RTE_CRYPTO_OP_STATUS_AUTH_FAILED;
-
-			/* Trim area used for digest from mbuf. */
-			rte_pktmbuf_trim(ops[i]->sym->m_src,
-					SNOW3G_DIGEST_LENGTH);
 		} else  {
 			dst = ops[i]->sym->auth.digest.data;
 
@@ -346,16 +340,16 @@ process_ops(struct rte_crypto_op **ops, struct snow3g_session *session,
 				session, num_ops);
 		break;
 	case SNOW3G_OP_ONLY_AUTH:
-		processed_ops = process_snow3g_hash_op(ops, session,
+		processed_ops = process_snow3g_hash_op(qp, ops, session,
 				num_ops);
 		break;
 	case SNOW3G_OP_CIPHER_AUTH:
 		processed_ops = process_snow3g_cipher_op(ops, session,
 				num_ops);
-		process_snow3g_hash_op(ops, session, processed_ops);
+		process_snow3g_hash_op(qp, ops, session, processed_ops);
 		break;
 	case SNOW3G_OP_AUTH_CIPHER:
-		processed_ops = process_snow3g_hash_op(ops, session,
+		processed_ops = process_snow3g_hash_op(qp, ops, session,
 				num_ops);
 		process_snow3g_cipher_op(ops, session, processed_ops);
 		break;
@@ -403,15 +397,15 @@ process_op_bit(struct rte_crypto_op *op, struct snow3g_session *session,
 				session);
 		break;
 	case SNOW3G_OP_ONLY_AUTH:
-		processed_op = process_snow3g_hash_op(&op, session, 1);
+		processed_op = process_snow3g_hash_op(qp, &op, session, 1);
 		break;
 	case SNOW3G_OP_CIPHER_AUTH:
 		processed_op = process_snow3g_cipher_op_bit(op, session);
 		if (processed_op == 1)
-			process_snow3g_hash_op(&op, session, 1);
+			process_snow3g_hash_op(qp, &op, session, 1);
 		break;
 	case SNOW3G_OP_AUTH_CIPHER:
-		processed_op = process_snow3g_hash_op(&op, session, 1);
+		processed_op = process_snow3g_hash_op(qp, &op, session, 1);
 		if (processed_op == 1)
 			process_snow3g_cipher_op_bit(op, session);
 		break;
diff --git a/drivers/crypto/snow3g/rte_snow3g_pmd_private.h b/drivers/crypto/snow3g/rte_snow3g_pmd_private.h
index fba3cb8..7b9729f 100644
--- a/drivers/crypto/snow3g/rte_snow3g_pmd_private.h
+++ b/drivers/crypto/snow3g/rte_snow3g_pmd_private.h
@@ -58,6 +58,8 @@
 #define SNOW3G_LOG_DBG(fmt, args...)
 #endif
 
+#define SNOW3G_DIGEST_LENGTH 4
+
 /** private data structure for each virtual SNOW 3G device */
 struct snow3g_private {
 	unsigned max_nb_queue_pairs;
@@ -78,6 +80,11 @@ struct snow3g_qp {
 	/**< Session Mempool */
 	struct rte_cryptodev_stats qp_stats;
 	/**< Queue pair statistics */
+	uint8_t temp_digest[SNOW3G_DIGEST_LENGTH];
+	/**< Buffer used to store the digest generated
+	 * by the driver when verifying a digest provided
+	 * by the user (using authentication verify operation)
+	 */
 } __rte_cache_aligned;
 
 enum snow3g_operation {
-- 
2.9.4