openssl_async/
accept.rs

1use std::mem;
2use std::pin::Pin;
3
4use openssl::ssl::{self, SslAcceptor};
5
6use futures::io::{AsyncRead, AsyncWrite};
7use futures::prelude::*;
8use futures::task::{Context, Poll};
9
10use async_stdio::*;
11
12use crate::{HandshakeError, MidHandshakeSslStream, SslStream};
13
14/// Extension for [SslAcceptor] to allow connections to be accepted
15/// asynchronously.
16pub trait SslAcceptorExt {
17    /// Asynchronously accept the connection
18    fn accept_async<S: AsyncRead + AsyncWrite>(&self, stream: S) -> AcceptAsync<S>;
19}
20
21impl SslAcceptorExt for SslAcceptor {
22    fn accept_async<S>(&self, stream: S) -> AcceptAsync<S>
23    where
24        S: AsyncRead + AsyncWrite,
25    {
26        AcceptAsync(AcceptInner::Init(self.clone(), stream))
27    }
28}
29
30/// The future returned from [SslAcceptorExt::accept_async]
31///
32/// Resolves to an [SslStream]
33pub struct AcceptAsync<S>(AcceptInner<S>);
34
35enum AcceptInner<S> {
36    Init(SslAcceptor, S),
37    Handshake(MidHandshakeSslStream<S>),
38    Done,
39}
40
41impl<S: AsyncRead + AsyncWrite + Unpin> Future for AcceptAsync<S> {
42    type Output = Result<SslStream<S>, HandshakeError<S>>;
43
44    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
45        let this = Pin::get_mut(self);
46
47        match mem::replace(&mut this.0, AcceptInner::Done) {
48            AcceptInner::Init(acceptor, stream) => {
49                let (stream, ctrl) = AsStdIo::new(stream, cx.waker().into());
50                match acceptor.accept(stream) {
51                    Ok(inner) => Poll::Ready(Ok(SslStream { inner, ctrl })),
52                    Err(ssl::HandshakeError::WouldBlock(inner)) => {
53                        this.0 = AcceptInner::Handshake(MidHandshakeSslStream::new(inner, ctrl));
54                        Poll::Pending
55                    }
56                    Err(e) => Poll::Ready(Err(HandshakeError::from_ssl(e, ctrl).unwrap())),
57                }
58            }
59            AcceptInner::Handshake(mut handshake) => match Pin::new(&mut handshake).poll(cx) {
60                Poll::Ready(result) => Poll::Ready(result),
61                Poll::Pending => {
62                    this.0 = AcceptInner::Handshake(handshake);
63                    Poll::Pending
64                }
65            },
66            AcceptInner::Done => panic!("accept polled after completion"),
67        }
68    }
69}