net/tls: pass record number as a byte array

TLS offload code casts record number to a u64.  The buffer
should be aligned to 8 bytes, but its actually a __be64, and
the rest of the TLS code treats it as big int.  Make the
offload callbacks take a byte array, drivers can make the
choice to do the ugly cast if they want to.

Prepare for copying the record number onto the stack by
defining a constant for max size of the byte array.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/tls.c

@@ -161,11 +161,12 @@ static void mlx5e_tls_del(struct net_device *netdev,
 }
 
 static void mlx5e_tls_resync_rx(struct net_device *netdev, struct sock *sk,
-				u32 seq, u64 rcd_sn)
+				u32 seq, u8 *rcd_sn_data)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct mlx5e_priv *priv = netdev_priv(netdev);
 	struct mlx5e_tls_offload_context_rx *rx_ctx;
+	u64 rcd_sn = *(u64 *)rcd_sn_data;
 
 	rx_ctx = mlx5e_get_tls_rx_context(tls_ctx);
 

include/net/tls.h

@@ -62,6 +62,7 @@
 #define TLS_DEVICE_NAME_MAX		32
 
 #define MAX_IV_SIZE			16
+#define TLS_MAX_REC_SEQ_SIZE		8
 
 /* For AES-CCM, the full 16-bytes of IV is made of '4' fields of given sizes.
  *
@@ -299,7 +300,7 @@ struct tlsdev_ops {
 			    struct tls_context *ctx,
 			    enum tls_offload_ctx_dir direction);
 	void (*tls_dev_resync_rx)(struct net_device *netdev,
-				  struct sock *sk, u32 seq, u64 rcd_sn);
+				  struct sock *sk, u32 seq, u8 *rcd_sn);
 };
 
 struct tls_offload_context_rx {
@@ -607,6 +608,6 @@ int tls_sw_fallback_init(struct sock *sk,
 int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx);
 
 void tls_device_offload_cleanup_rx(struct sock *sk);
-void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn);
+void handle_device_resync(struct sock *sk, u32 seq);
 
 #endif /* _TLS_OFFLOAD_H */

net/tls/tls_device.c

@@ -551,7 +551,7 @@ void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
 }
 
 static void tls_device_resync_rx(struct tls_context *tls_ctx,
-				 struct sock *sk, u32 seq, u64 rcd_sn)
+				 struct sock *sk, u32 seq, u8 *rcd_sn)
 {
 	struct net_device *netdev;
 
@@ -563,7 +563,7 @@ static void tls_device_resync_rx(struct tls_context *tls_ctx,
 	clear_bit_unlock(TLS_RX_SYNC_RUNNING, &tls_ctx->flags);
 }
 
-void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn)
+void handle_device_resync(struct sock *sk, u32 seq)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_offload_context_rx *rx_ctx;
@@ -582,7 +582,7 @@ void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn)
 
 	if (unlikely(is_req_pending) && req_seq == seq &&
 	    atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
-		tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
+		tls_device_resync_rx(tls_ctx, sk, seq, tls_ctx->rx.rec_seq);
 }
 
 static int tls_device_reencrypt(struct sock *sk, struct sk_buff *skb)
@@ -760,6 +760,12 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 		goto free_offload_ctx;
 	}
 
+	/* Sanity-check the rec_seq_size for stack allocations */
+	if (rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
+		rc = -EINVAL;
+		goto free_offload_ctx;
+	}
+
 	prot->prepend_size = TLS_HEADER_SIZE + nonce_size;
 	prot->tag_size = tag_size;
 	prot->overhead_size = prot->prepend_size + prot->tag_size;

net/tls/tls_sw.c

@@ -2015,8 +2015,7 @@ static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
 		goto read_failure;
 	}
 #ifdef CONFIG_TLS_DEVICE
-	handle_device_resync(strp->sk, TCP_SKB_CB(skb)->seq + rxm->offset,
-			     *(u64*)tls_ctx->rx.rec_seq);
+	handle_device_resync(strp->sk, TCP_SKB_CB(skb)->seq + rxm->offset);
 #endif
 	return data_len + TLS_HEADER_SIZE;
 
@@ -2283,8 +2282,9 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 		goto free_priv;
 	}
 
-	/* Sanity-check the IV size for stack allocations. */
-	if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE) {
+	/* Sanity-check the sizes for stack allocations. */
+	if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE ||
+	    rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
 		rc = -EINVAL;
 		goto free_priv;
 	}