[PATCH v21 04/20] net/tls,core: export get_netdev_for_sock

Aurelien Aptel
2023-12-14T13:27:06Z

* remove netdev_sk_get_lowest_dev() from net/core
* move get_netdev_for_sock() from net/tls to net/core

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.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Shai Malin <smalin@nvidia.com>
Signed-off-by: Aurelien Aptel <aaptel@nvidia.com>
---
include/linux/netdevice.h | 3 +--
net/core/dev.c | 26 +++++++++++++-------------
net/tls/tls_device.c | 16 ----------------
3 files changed, 14 insertions(+), 31 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3ddabe42d8c8..52bf095f87fd 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3202,8 +3202,7 @@ int init_dummy_netdev(struct net_device *dev);
struct net_device *netdev_get_xmit_slave(struct net_device *dev,
struct sk_buff *skb,
bool all_slaves);
-struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
- struct sock *sk);
+struct net_device *get_netdev_for_sock(struct sock *sk);
struct net_device *dev_get_by_index(struct net *net, int ifindex);
struct net_device *__dev_get_by_index(struct net *net, int ifindex);
struct net_device *netdev_get_by_index(struct net *net, int ifindex,
diff --git a/net/core/dev.c b/net/core/dev.c
index 0432b04cf9b0..facf3d35aaad 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8263,27 +8263,27 @@ static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
}

/**
- * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
- * @dev: device
+ * get_netdev_for_sock - Get the lowest device in socket
* @sk: the socket
*
- * %NULL is returned if no lower device is found.
+ * Assumes that the socket is already connected.
+ * Returns the lower device or %NULL if no lower device is found.
*/
-
-struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
- struct sock *sk)
+struct net_device *get_netdev_for_sock(struct sock *sk)
{
- struct net_device *lower;
+ struct dst_entry *dst = sk_dst_get(sk);
+ struct net_device *dev, *lower;

- lower = netdev_sk_get_lower_dev(dev, sk);
- while (lower) {
+ if (unlikely(!dst))
+ return NULL;
+ dev = dst->dev;
+ while ((lower = netdev_sk_get_lower_dev(dev, sk)))
dev = lower;
- lower = netdev_sk_get_lower_dev(dev, sk);
- }
-
+ dev_hold(dev);
+ dst_release(dst);
return dev;
}
-EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
+EXPORT_SYMBOL_GPL(get_netdev_for_sock);

static void netdev_adjacent_add_links(struct net_device *dev)
{
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index bf8ed36b1ad6..fb94b3e777aa 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -119,22 +119,6 @@ static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
tls_device_free_ctx(ctx);
}

-/* 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;
--
2.34.1