[PATCH v23 04/20] net/tls,core: export get_netdev_for_sock

Aurelien Aptel
2024-02-28T12:58:21Z

* remove netdev_sk_get_lowest_dev() from net/core
* move get_netdev_for_sock() from net/tls to net/core
* update exising users in net/tls/tls_device.c

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 | 5 +++--
net/core/dev.c | 30 +++++++++++++++++-------------
net/tls/tls_device.c | 31 +++++++++----------------------
3 files changed, 29 insertions(+), 37 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 610d0530c9f9..9dda1a5f3dbb 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3209,8 +3209,9 @@ void 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,
+ netdevice_tracker *tracker,
+ gfp_t gfp);
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 cc9c2eda65ac..e839a6b4fdf3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8315,27 +8315,31 @@ 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
+ * @tracker: tracking object for the acquired reference
+ * @gfp: allocation flags for the tracker
*
- * %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,
+ netdevice_tracker *tracker,
+ gfp_t gfp)
{
- 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);
- }
-
+ netdev_hold(dev, tracker, gfp);
+ 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..5868daf36ae2 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;
@@ -1063,6 +1047,7 @@ int tls_set_device_offload(struct sock *sk)
struct tls_offload_context_tx *offload_ctx;
const struct tls_cipher_desc *cipher_desc;
struct tls_crypto_info *crypto_info;
+ netdevice_tracker netdev_tracker;
struct tls_prot_info *prot;
struct net_device *netdev;
struct tls_context *ctx;
@@ -1076,7 +1061,7 @@ int tls_set_device_offload(struct sock *sk)
if (ctx->priv_ctx_tx)
return -EEXIST;

- netdev = get_netdev_for_sock(sk);
+ netdev = get_netdev_for_sock(sk, &netdev_tracker, GFP_KERNEL);
if (!netdev) {
pr_err_ratelimited("%s: netdev not found\n", __func__);
return -EINVAL;
@@ -1172,7 +1157,7 @@ int tls_set_device_offload(struct sock *sk)
* by the netdev's xmit function.
*/
smp_store_release(&sk->sk_validate_xmit_skb, tls_validate_xmit_skb);
- dev_put(netdev);
+ netdev_put(netdev, &netdev_tracker);

return 0;

@@ -1186,7 +1171,7 @@ int tls_set_device_offload(struct sock *sk)
free_marker_record:
kfree(start_marker_record);
release_netdev:
- dev_put(netdev);
+ netdev_put(netdev, &netdev_tracker);
return rc;
}

@@ -1194,13 +1179,15 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
{
struct tls12_crypto_info_aes_gcm_128 *info;
struct tls_offload_context_rx *context;
+ netdevice_tracker netdev_tracker;
struct net_device *netdev;
+
int rc = 0;

if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
return -EOPNOTSUPP;

- netdev = get_netdev_for_sock(sk);
+ netdev = get_netdev_for_sock(sk, &netdev_tracker, GFP_KERNEL);
if (!netdev) {
pr_err_ratelimited("%s: netdev not found\n", __func__);
return -EINVAL;
@@ -1249,7 +1236,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
tls_device_attach(ctx, sk, netdev);
up_read(&device_offload_lock);

- dev_put(netdev);
+ netdev_put(netdev, &netdev_tracker);

return 0;

@@ -1262,7 +1249,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
release_lock:
up_read(&device_offload_lock);
release_netdev:
- dev_put(netdev);
+ netdev_put(netdev, &netdev_tracker);
return rc;
}

--
2.34.1