sunset_async/server.rs
1use embedded_io_async::{Read, Write};
2
3use sunset::*;
4
5use crate::*;
6use async_sunset::{AsyncSunset, ProgressHolder};
7
8/// An async SSH server instance
9///
10/// The [`run()`][Self::run] method runs the session to completion. [`progress()`][Self::progress]
11/// must be polled, and responses given to the events provided.
12///
13/// Once the client has opened sessions, those can be retrieved with [`stdio()`][Self::stdio]
14/// and [`stdio_stderr()`][Self::stdio_stderr] methods.
15///
16/// This is async executor agnostic.
17#[derive(Debug)]
18pub struct SSHServer<'a> {
19 sunset: AsyncSunset<'a, sunset::Server>,
20}
21
22impl<'a> SSHServer<'a> {
23 // May return an error if RNG fails
24 pub fn new(inbuf: &'a mut [u8], outbuf: &'a mut [u8]) -> Self {
25 let runner = Runner::new_server(inbuf, outbuf);
26 let sunset = AsyncSunset::new(runner);
27 Self { sunset }
28 }
29
30 /// Runs the session to completion.
31 ///
32 /// `rsock` and `wsock` are the SSH network channel (TCP port 22 or equivalent).
33 pub async fn run(
34 &self,
35 rsock: &mut impl Read,
36 wsock: &mut impl Write,
37 ) -> Result<()> {
38 self.sunset.run(rsock, wsock).await
39 }
40
41 /// Returns an event from the SSH session.
42 ///
43 /// Note that on return `ProgressHolder` holds a mutex over the session,
44 /// so most other calls to `SSHServer` will block until the `ProgressHolder`
45 /// is dropped.
46 pub async fn progress<'g, 'f>(
47 &'g self,
48 ph: &'f mut ProgressHolder<'g, 'a, sunset::Server>,
49 ) -> Result<ServEvent<'f, 'a>> {
50 // poll until we get an actual event to return
51 match self.sunset.progress(ph).await? {
52 Event::Serv(x) => Ok(x),
53 Event::None => Ok(ServEvent::PollAgain),
54 Event::Progressed => Ok(ServEvent::PollAgain),
55 Event::Cli(_) => Err(Error::bug()),
56 }
57 }
58
59 /// Returns a [`ChanInOut`] representing a channel.
60 ///
61 /// `ch` is the [`ChanHandle`] returned after accepting a [`ServEvent::OpenSession`] event.
62 /// If `stderr` is also needed, use [`stdio_stderr()`](Self::stdio_stderr) instead.
63 pub async fn stdio(&self, ch: ChanHandle) -> Result<ChanInOut<'_>> {
64 Ok(ChanInOut::new(self.sunset.add_channel(ch).await?))
65 }
66
67 /// Retrieve the stdin/stdout/stderr streams.
68 ///
69 /// See [`stdio()`](Self::stdio).
70 pub async fn stdio_stderr(
71 &self,
72 ch: ChanHandle,
73 ) -> Result<(ChanInOut<'_>, ChanOut<'_>)> {
74 let io_normal = self.sunset.add_channel(ch).await?;
75 let e = ChanOut::new(io_normal.clone_stderr());
76 let i = ChanInOut::new(io_normal);
77 Ok((i, e))
78 }
79}