[PATCH net-next v7] net/tls: Use socket data_ready callback on record availability

[PATCH net-next v7] net/tls: Use socket data_ready callback on record availability

[Vakul Garg]

On receipt of a complete tls record, use socket's saved data_ready
callback instead of state_change callback. In function tls_queue(),
the TLS record is queued in encrypted state. But the decryption
happen inline when tls_sw_recvmsg() or tls_sw_splice_read() get invoked.
So it should be ok to notify the waiting context about the availability
of data as soon as we could collect a full TLS record. For new data
availability notification, sk_data_ready callback is more appropriate.
It points to sock_def_readable() which wakes up specifically for EPOLLIN
event. This is in contrast to the socket callback sk_state_change which
points to sock_def_wakeup() which issues a wakeup unconditionally
(without event mask).

Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
---
v6->v7: Improved the commit message to contain the detailed reasoning.
(The same analysis was shared on the mail list.)

 net/tls/tls_sw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 6deceb7c56ba..33838f11fafa 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1028,7 +1028,7 @@ static void tls_queue(struct strparser *strp, struct sk_buff *skb)
 	ctx->recv_pkt = skb;
 	strp_pause(strp);
 
-	strp->sk->sk_state_change(strp->sk);
+	ctx->saved_data_ready(strp->sk);
 }
 
 static void tls_data_ready(struct sock *sk)
-- 
2.13.6

Re: [PATCH net-next v7] net/tls: Use socket data_ready callback on record availability

[David Miller]

From: Vakul Garg <vakul.garg@nxp.com>
Date: Mon, 30 Jul 2018 16:08:33 +0530

> On receipt of a complete tls record, use socket's saved data_ready
> callback instead of state_change callback. In function tls_queue(),
> the TLS record is queued in encrypted state. But the decryption
> happen inline when tls_sw_recvmsg() or tls_sw_splice_read() get invoked.
> So it should be ok to notify the waiting context about the availability
> of data as soon as we could collect a full TLS record. For new data
> availability notification, sk_data_ready callback is more appropriate.
> It points to sock_def_readable() which wakes up specifically for EPOLLIN
> event. This is in contrast to the socket callback sk_state_change which
> points to sock_def_wakeup() which issues a wakeup unconditionally
> (without event mask).
> 
> Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
> ---
> v6->v7: Improved the commit message to contain the detailed reasoning.
> (The same analysis was shared on the mail list.)

Applied.