Subject: [PATCH v5 net-next 04/36] net/tls: expose get_netdev_for_sock

From: Boris Pismenny <[email-masked]>
Date: Thu, 22 Jul 2021 14:02:53 +0300

From: Boris Pismenny <[email-masked]>

get_netdev_for_sock is a utility that is used to obtain
the net_device structure from a connected socket.

Later patches will use this for nvme-tcp DDP and DDP DDGST offloads.

Signed-off-by: Boris Pismenny <[email-masked]>
Reviewed-by: Sagi Grimberg <[email-masked]>
---
 include/net/sock.h   | 17 +++++++++++++++++
 net/tls/tls_device.c | 20 ++------------------
 2 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 8bdd80027ffb..5fa2fd192d18 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2769,4 +2769,21 @@ void sock_set_sndtimeo(struct sock *sk, s64 secs);
 
 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
 
+/* Assume that the socket is already connected */
+static inline struct net_device *get_netdev_for_sock(struct sock *sk, bool hold)
+{
+	struct dst_entry *dst = sk_dst_get(sk);
+	struct net_device *netdev = NULL;
+
+	if (likely(dst)) {
+		netdev = dst->dev;
+		if (hold)
+			dev_hold(netdev);
+	}
+
+	dst_release(dst);
+
+	return netdev;
+}
+
 #endif	/* _SOCK_H */
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index b932469ee69c..06aa5f1e73d1 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -107,22 +107,6 @@ static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
 	spin_unlock_irqrestore(&tls_device_lock, flags);
 }
 
-/* We assume that the socket is already connected */
-static struct net_device *get_netdev_for_sock(struct sock *sk)
-{
-	struct dst_entry *dst = sk_dst_get(sk);
-	struct net_device *netdev = NULL;
-
-	if (likely(dst)) {
-		netdev = netdev_sk_get_lowest_dev(dst->dev, sk);
-		dev_hold(netdev);
-	}
-
-	dst_release(dst);
-
-	return netdev;
-}
-
 static void destroy_record(struct tls_record_info *record)
 {
 	int i;
@@ -1118,7 +1102,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 	if (skb)
 		TCP_SKB_CB(skb)->eor = 1;
 
-	netdev = get_netdev_for_sock(sk);
+	netdev = get_netdev_for_sock(sk, true);
 	if (!netdev) {
 		pr_err_ratelimited("%s: netdev not found\n", __func__);
 		rc = -EINVAL;
@@ -1194,7 +1178,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 	if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
 		return -EOPNOTSUPP;
 
-	netdev = get_netdev_for_sock(sk);
+	netdev = get_netdev_for_sock(sk, true);
 	if (!netdev) {
 		pr_err_ratelimited("%s: netdev not found\n", __func__);
 		return -EINVAL;
-- 
2.24.1