1use std::future::Future;
2use std::ops::{Deref, DerefMut};
3use std::pin::Pin;
4use std::task::{Context, Poll};
5use std::{io, mem};
6
7use rustls::server::AcceptedAlert;
8use rustls::{ConnectionCommon, SideData};
9use tokio::io::{AsyncRead, AsyncWrite};
10
11use crate::common::{Stream, SyncWriteAdapter, TlsState};
12
13pub(crate) trait IoSession {
14 type Io;
15 type Session;
16
17 fn skip_handshake(&self) -> bool;
18 fn get_mut(&mut self) -> (&mut TlsState, &mut Self::Io, &mut Self::Session);
19 fn into_io(self) -> Self::Io;
20}
21
22pub(crate) enum MidHandshake<IS: IoSession> {
23 Handshaking(IS),
24 End,
25 SendAlert {
26 io: IS::Io,
27 alert: AcceptedAlert,
28 error: io::Error,
29 },
30 Error {
31 io: IS::Io,
32 error: io::Error,
33 },
34}
35
36impl<IS, SD> Future for MidHandshake<IS>
37where
38 IS: IoSession + Unpin,
39 IS::Io: AsyncRead + AsyncWrite + Unpin,
40 IS::Session: DerefMut + Deref<Target = ConnectionCommon<SD>> + Unpin,
41 SD: SideData,
42{
43 type Output = Result<IS, (io::Error, IS::Io)>;
44
45 fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
46 let this = self.get_mut();
47
48 let mut stream = match mem::replace(this, MidHandshake::End) {
49 MidHandshake::Handshaking(stream) => stream,
50 MidHandshake::SendAlert {
51 mut io,
52 mut alert,
53 error,
54 } => loop {
55 match alert.write(&mut SyncWriteAdapter { io: &mut io, cx }) {
56 Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
57 *this = MidHandshake::SendAlert { io, error, alert };
58 return Poll::Pending;
59 }
60 Err(_) | Ok(0) => return Poll::Ready(Err((error, io))),
61 Ok(_) => {}
62 };
63 },
64 // Starting the handshake returned an error; fail the future immediately.
65 MidHandshake::Error { io, error } => return Poll::Ready(Err((error, io))),
66 _ => panic!("unexpected polling after handshake"),
67 };
68
69 if !stream.skip_handshake() {
70 let (state, io, session) = stream.get_mut();
71 let mut tls_stream = Stream::new(io, session).set_eof(!state.readable());
72
73 macro_rules! try_poll {
74 ( $e:expr ) => {
75 match $e {
76 Poll::Ready(Ok(_)) => (),
77 Poll::Ready(Err(err)) => return Poll::Ready(Err((err, stream.into_io()))),
78 Poll::Pending => {
79 *this = MidHandshake::Handshaking(stream);
80 return Poll::Pending;
81 }
82 }
83 };
84 }
85
86 while tls_stream.session.is_handshaking() {
87 try_poll!(tls_stream.handshake(cx));
88 }
89
90 try_poll!(Pin::new(&mut tls_stream).poll_flush(cx));
91 }
92
93 Poll::Ready(Ok(stream))
94 }
95}
96