Merge branch 'tls-add-support-for-kernel-driven-resync-and-nfp-RX-offload'

Jakub Kicinski says:

====================
tls: add support for kernel-driven resync and nfp RX offload

This series adds TLS RX offload for NFP and completes the offload
by providing resync strategies.  When TLS data stream looses segments
or experiences reorder NIC can no longer perform in line offload.
Resyncs provide information about placement of records in the
stream so that offload can resume.

Existing TLS resync mechanisms are not a great fit for the NFP.
In particular the TX resync is hard to implement for packet-centric
NICs.  This patchset adds an ability to perform TX resync in a way
similar to the way initial sync is done - by calling down to the
driver when new record is created after driver indicated sync had
been lost.

Similarly on the RX side, we try to wait for a gap in the stream
and send record information for the next record.  This works very
well for RPC workloads which are the primary focus at this time.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 132 insertions, 17 deletions

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 43f2deb57078..40076f423dcb 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -209,6 +209,29 @@ void tls_device_free_resources_tx(struct sock *sk)
 	tls_free_partial_record(sk, tls_ctx);
 }
 
+static void tls_device_resync_tx(struct sock *sk, struct tls_context *tls_ctx,
+				 u32 seq)
+{
+	struct net_device *netdev;
+	struct sk_buff *skb;
+	u8 *rcd_sn;
+
+	skb = tcp_write_queue_tail(sk);
+	if (skb)
+		TCP_SKB_CB(skb)->eor = 1;
+
+	rcd_sn = tls_ctx->tx.rec_seq;
+
+	down_read(&device_offload_lock);
+	netdev = tls_ctx->netdev;
+	if (netdev)
+		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
+						   TLS_OFFLOAD_CTX_DIR_TX);
+	up_read(&device_offload_lock);
+
+	clear_bit_unlock(TLS_TX_SYNC_SCHED, &tls_ctx->flags);
+}
+
 static void tls_append_frag(struct tls_record_info *record,
 			    struct page_frag *pfrag,
 			    int size)
@@ -264,6 +287,10 @@ static int tls_push_record(struct sock *sk,
 	list_add_tail(&record->list, &offload_ctx->records_list);
 	spin_unlock_irq(&offload_ctx->lock);
 	offload_ctx->open_record = NULL;
+
+	if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags))
+		tls_device_resync_tx(sk, ctx, tp->write_seq);
+
 	tls_advance_record_sn(sk, prot, &ctx->tx);
 
 	for (i = 0; i < record->num_frags; i++) {
@@ -551,7 +578,7 @@ 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;
 
@@ -559,14 +586,17 @@ static void tls_device_resync_rx(struct tls_context *tls_ctx,
 		return;
 	netdev = READ_ONCE(tls_ctx->netdev);
 	if (netdev)
-		netdev->tlsdev_ops->tls_dev_resync_rx(netdev, sk, seq, rcd_sn);
+		netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn,
+						   TLS_OFFLOAD_CTX_DIR_RX);
 	clear_bit_unlock(TLS_RX_SYNC_RUNNING, &tls_ctx->flags);
 }
 
-void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn)
+void tls_device_rx_resync_new_rec(struct sock *sk, u32 rcd_len, u32 seq)
 {
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_offload_context_rx *rx_ctx;
+	u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
+	struct tls_prot_info *prot;
 	u32 is_req_pending;
 	s64 resync_req;
 	u32 req_seq;
@@ -574,15 +604,83 @@ void handle_device_resync(struct sock *sk, u32 seq, u64 rcd_sn)
 	if (tls_ctx->rx_conf != TLS_HW)
 		return;
 
+	prot = &tls_ctx->prot_info;
 	rx_ctx = tls_offload_ctx_rx(tls_ctx);
-	resync_req = atomic64_read(&rx_ctx->resync_req);
-	req_seq = (resync_req >> 32) - ((u32)TLS_HEADER_SIZE - 1);
-	is_req_pending = resync_req;
+	memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
 
-	if (unlikely(is_req_pending) && req_seq == seq &&
-	    atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0)) {
+	switch (rx_ctx->resync_type) {
+	case TLS_OFFLOAD_SYNC_TYPE_DRIVER_REQ:
+		resync_req = atomic64_read(&rx_ctx->resync_req);
+		req_seq = resync_req >> 32;
 		seq += TLS_HEADER_SIZE - 1;
-		tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
+		is_req_pending = resync_req;
+
+		if (likely(!is_req_pending) || req_seq != seq ||
+		    !atomic64_try_cmpxchg(&rx_ctx->resync_req, &resync_req, 0))
+			return;
+		break;
+	case TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT:
+		if (likely(!rx_ctx->resync_nh_do_now))
+			return;
+
+		/* head of next rec is already in, note that the sock_inq will
+		 * include the currently parsed message when called from parser
+		 */
+		if (tcp_inq(sk) > rcd_len)
+			return;
+
+		rx_ctx->resync_nh_do_now = 0;
+		seq += rcd_len;
+		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
+		break;
+	}
+
+	tls_device_resync_rx(tls_ctx, sk, seq, rcd_sn);
+}
+
+static void tls_device_core_ctrl_rx_resync(struct tls_context *tls_ctx,
+					   struct tls_offload_context_rx *ctx,
+					   struct sock *sk, struct sk_buff *skb)
+{
+	struct strp_msg *rxm;
+
+	/* device will request resyncs by itself based on stream scan */
+	if (ctx->resync_type != TLS_OFFLOAD_SYNC_TYPE_CORE_NEXT_HINT)
+		return;
+	/* already scheduled */
+	if (ctx->resync_nh_do_now)
+		return;
+	/* seen decrypted fragments since last fully-failed record */
+	if (ctx->resync_nh_reset) {
+		ctx->resync_nh_reset = 0;
+		ctx->resync_nh.decrypted_failed = 1;
+		ctx->resync_nh.decrypted_tgt = TLS_DEVICE_RESYNC_NH_START_IVAL;
+		return;
+	}
+
+	if (++ctx->resync_nh.decrypted_failed <= ctx->resync_nh.decrypted_tgt)
+		return;
+
+	/* doing resync, bump the next target in case it fails */
+	if (ctx->resync_nh.decrypted_tgt < TLS_DEVICE_RESYNC_NH_MAX_IVAL)
+		ctx->resync_nh.decrypted_tgt *= 2;
+	else
+		ctx->resync_nh.decrypted_tgt += TLS_DEVICE_RESYNC_NH_MAX_IVAL;
+
+	rxm = strp_msg(skb);
+
+	/* head of next rec is already in, parser will sync for us */
+	if (tcp_inq(sk) > rxm->full_len) {
+		ctx->resync_nh_do_now = 1;
+	} else {
+		struct tls_prot_info *prot = &tls_ctx->prot_info;
+		u8 rcd_sn[TLS_MAX_REC_SEQ_SIZE];
+
+		memcpy(rcd_sn, tls_ctx->rx.rec_seq, prot->rec_seq_size);
+		tls_bigint_increment(rcd_sn, prot->rec_seq_size);
+
+		tls_device_resync_rx(tls_ctx, sk, tcp_sk(sk)->copied_seq,
+				     rcd_sn);
 	}
 }
 
@@ -687,12 +785,21 @@ int tls_device_decrypted(struct sock *sk, struct sk_buff *skb)
 
 	ctx->sw.decrypted |= is_decrypted;
 
-	/* Return immedeatly if the record is either entirely plaintext or
+	/* Return immediately if the record is either entirely plaintext or
 	 * entirely ciphertext. Otherwise handle reencrypt partially decrypted
 	 * record.
 	 */
-	return (is_encrypted || is_decrypted) ? 0 :
-		tls_device_reencrypt(sk, skb);
+	if (is_decrypted) {
+		ctx->resync_nh_reset = 1;
+		return 0;
+	}
+	if (is_encrypted) {
+		tls_device_core_ctrl_rx_resync(tls_ctx, ctx, sk, skb);
+		return 0;
+	}
+
+	ctx->resync_nh_reset = 1;
+	return tls_device_reencrypt(sk, skb);
 }
 
 static void tls_device_attach(struct tls_context *ctx, struct sock *sk,
@@ -761,6 +868,12 @@ 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;
@@ -912,6 +1025,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 		rc = -ENOMEM;
 		goto release_netdev;
 	}
+	context->resync_nh_reset = 1;
 
 	ctx->priv_ctx_rx = context;
 	rc = tls_set_sw_offload(sk, ctx, 0);
@@ -1019,7 +1133,7 @@ static int tls_dev_event(struct notifier_block *this, unsigned long event,
 	case NETDEV_REGISTER:
 	case NETDEV_FEAT_CHANGE:
 		if ((dev->features & NETIF_F_HW_TLS_RX) &&
-		    !dev->tlsdev_ops->tls_dev_resync_rx)
+		    !dev->tlsdev_ops->tls_dev_resync)
 			return NOTIFY_BAD;
 
 		if  (dev->tlsdev_ops &&
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index bef71e54fad0..533eaa4826e5 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2015,8 +2015,8 @@ 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);
+	tls_device_rx_resync_new_rec(strp->sk, data_len + TLS_HEADER_SIZE,
+				     TCP_SKB_CB(skb)->seq + rxm->offset);
 #endif
 	return data_len + TLS_HEADER_SIZE;
 
@@ -2283,8 +2283,9 @@ 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;
 	}