tls: suppress wakeups unless we have a full record

TLS does not override .poll() so TLS-enabled socket will generate
an event whenever data arrives at the TCP socket. This leads to
unnecessary wakeups on slow connections.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 3d45fdb5c4e942c46daa86f3243c560c1f1be00f..e02a0d882ed3b359d7692bec761d3f30cf24a86f 100644 (file)
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -358,6 +358,39 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
                tls_ctx_free(sk, ctx);
 }
 
+static __poll_t tls_sk_poll(struct file *file, struct socket *sock,
+                           struct poll_table_struct *wait)
+{
+       struct tls_sw_context_rx *ctx;
+       struct tls_context *tls_ctx;
+       struct sock *sk = sock->sk;
+       struct sk_psock *psock;
+       __poll_t mask = 0;
+       u8 shutdown;
+       int state;
+
+       mask = tcp_poll(file, sock, wait);
+
+       state = inet_sk_state_load(sk);
+       shutdown = READ_ONCE(sk->sk_shutdown);
+       if (unlikely(state != TCP_ESTABLISHED || shutdown & RCV_SHUTDOWN))
+               return mask;
+
+       tls_ctx = tls_get_ctx(sk);
+       ctx = tls_sw_ctx_rx(tls_ctx);
+       psock = sk_psock_get(sk);
+
+       if (skb_queue_empty_lockless(&ctx->rx_list) &&
+           !tls_strp_msg_ready(ctx) &&
+           sk_psock_queue_empty(psock))
+               mask &= ~(EPOLLIN | EPOLLRDNORM);
+
+       if (psock)
+               sk_psock_put(sk, psock);
+
+       return mask;
+}
+
 static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                                  int __user *optlen, int tx)
 {
@@ -928,9 +961,11 @@ static void build_proto_ops(struct proto_ops ops[TLS_NUM_CONFIG][TLS_NUM_CONFIG]
 
        ops[TLS_BASE][TLS_SW  ] = ops[TLS_BASE][TLS_BASE];
        ops[TLS_BASE][TLS_SW  ].splice_read     = tls_sw_splice_read;
+       ops[TLS_BASE][TLS_SW  ].poll            = tls_sk_poll;
 
        ops[TLS_SW  ][TLS_SW  ] = ops[TLS_SW  ][TLS_BASE];
        ops[TLS_SW  ][TLS_SW  ].splice_read     = tls_sw_splice_read;
+       ops[TLS_SW  ][TLS_SW  ].poll            = tls_sk_poll;
 
 #ifdef CONFIG_TLS_DEVICE
        ops[TLS_HW  ][TLS_BASE] = ops[TLS_BASE][TLS_BASE];