[PATCH net-next v2 2/2] net/tls: optimize judgement processes in tls_set_device_offload()

From: Ziyang Xuan
Date: Fri Mar 18 2022 - 22:58:02 EST


It is known that priority setting HW offload when set tls TX/RX offload
by setsockopt(). Check netdevice whether support NETIF_F_HW_TLS_TX or
not at the later stages in the whole tls_set_device_offload() process,
some memory allocations have been done before that. We must release those
memory and return error if we judge the netdevice not support
NETIF_F_HW_TLS_TX. It is redundant.

Move NETIF_F_HW_TLS_TX judgement forward, and move start_marker_record
and offload_ctx memory allocation back slightly. Thus, we can get
simpler exception handling process.

Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
---
net/tls/tls_device.c | 62 ++++++++++++++++++++++----------------------
1 file changed, 31 insertions(+), 31 deletions(-)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index b932469ee69c..12f7b56771d9 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -1028,20 +1028,21 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
if (ctx->priv_ctx_tx)
return -EEXIST;

- start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
- if (!start_marker_record)
- return -ENOMEM;
+ netdev = get_netdev_for_sock(sk);
+ if (!netdev) {
+ pr_err_ratelimited("%s: netdev not found\n", __func__);
+ return -EINVAL;
+ }

- offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
- if (!offload_ctx) {
- rc = -ENOMEM;
- goto free_marker_record;
+ if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
+ rc = -EOPNOTSUPP;
+ goto release_netdev;
}

crypto_info = &ctx->crypto_send.info;
if (crypto_info->version != TLS_1_2_VERSION) {
rc = -EOPNOTSUPP;
- goto free_offload_ctx;
+ goto release_netdev;
}

switch (crypto_info->cipher_type) {
@@ -1057,13 +1058,13 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
break;
default:
rc = -EINVAL;
- goto free_offload_ctx;
+ goto release_netdev;
}

/* Sanity-check the rec_seq_size for stack allocations */
if (rec_seq_size > TLS_MAX_REC_SEQ_SIZE) {
rc = -EINVAL;
- goto free_offload_ctx;
+ goto release_netdev;
}

prot->version = crypto_info->version;
@@ -1077,7 +1078,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
GFP_KERNEL);
if (!ctx->tx.iv) {
rc = -ENOMEM;
- goto free_offload_ctx;
+ goto release_netdev;
}

memcpy(ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv, iv_size);
@@ -1089,9 +1090,21 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
goto free_iv;
}

+ start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
+ if (!start_marker_record) {
+ rc = -ENOMEM;
+ goto free_rec_seq;
+ }
+
+ offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
+ if (!offload_ctx) {
+ rc = -ENOMEM;
+ goto free_marker_record;
+ }
+
rc = tls_sw_fallback_init(sk, offload_ctx, crypto_info);
if (rc)
- goto free_rec_seq;
+ goto free_offload_ctx;

/* start at rec_seq - 1 to account for the start marker record */
memcpy(&rcd_sn, ctx->tx.rec_seq, sizeof(rcd_sn));
@@ -1118,18 +1131,6 @@ 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);
- if (!netdev) {
- pr_err_ratelimited("%s: netdev not found\n", __func__);
- rc = -EINVAL;
- goto disable_cad;
- }
-
- if (!(netdev->features & NETIF_F_HW_TLS_TX)) {
- rc = -EOPNOTSUPP;
- goto release_netdev;
- }
-
/* Avoid offloading if the device is down
* We don't want to offload new flows after
* the NETDEV_DOWN event
@@ -1167,20 +1168,19 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)

release_lock:
up_read(&device_offload_lock);
-release_netdev:
- dev_put(netdev);
-disable_cad:
clean_acked_data_disable(inet_csk(sk));
crypto_free_aead(offload_ctx->aead_send);
-free_rec_seq:
- kfree(ctx->tx.rec_seq);
-free_iv:
- kfree(ctx->tx.iv);
free_offload_ctx:
kfree(offload_ctx);
ctx->priv_ctx_tx = NULL;
free_marker_record:
kfree(start_marker_record);
+free_rec_seq:
+ kfree(ctx->tx.rec_seq);
+free_iv:
+ kfree(ctx->tx.iv);
+release_netdev:
+ dev_put(netdev);
return rc;
}

--
2.25.1