1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
// Copyright 2017-2019 Parity Technologies (UK) Ltd.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

//! Implementation of the libp2p `Transport` trait for Websockets.

#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]

pub mod error;
pub mod framed;
mod quicksink;
pub mod tls;

use error::Error;
use framed::{Connection, Incoming};
use futures::{future::BoxFuture, prelude::*, ready};
use libp2p_core::{
    connection::ConnectedPoint,
    multiaddr::Multiaddr,
    transport::{map::MapFuture, ListenerId, TransportError, TransportEvent},
    Transport,
};
use rw_stream_sink::RwStreamSink;
use std::{
    io,
    pin::Pin,
    task::{Context, Poll},
};

/// A Websocket transport.
///
/// DO NOT wrap this transport with a DNS transport if you want Secure Websockets to work.
///
/// A Secure Websocket transport needs to wrap DNS transport to resolve domain names after
/// they are checked against the remote certificates. Use a combination of DNS and TCP transports
/// to build a Secure Websocket transport.
///
/// If you don't need Secure Websocket's support, use a plain TCP transport as an inner transport.
///
/// # Dependencies
///
/// This transport requires the `zlib` shared library to be installed on the system.
///
/// Future releases might lift this requirement, see <https://github.com/paritytech/soketto/issues/72>.
///
/// # Examples
///
/// Secure Websocket transport:
///
/// ```
/// # use futures::future;
/// # use libp2p_core::{transport::ListenerId, Transport};
/// # use libp2p_dns as dns;
/// # use libp2p_tcp as tcp;
/// # use libp2p_websocket as websocket;
/// # use rcgen::generate_simple_self_signed;
/// # use std::pin::Pin;
/// #
/// # #[async_std::main]
/// # async fn main() {
///
/// let mut transport = websocket::WsConfig::new(dns::async_std::Transport::system(
///     tcp::async_io::Transport::new(tcp::Config::default()),
/// ).await.unwrap());
///
/// let rcgen_cert = generate_simple_self_signed(vec!["localhost".to_string()]).unwrap();
/// let priv_key = websocket::tls::PrivateKey::new(rcgen_cert.serialize_private_key_der());
/// let cert = websocket::tls::Certificate::new(rcgen_cert.serialize_der().unwrap());
/// transport.set_tls_config(websocket::tls::Config::new(priv_key, vec![cert]).unwrap());
///
/// let id = transport.listen_on(ListenerId::next(), "/ip4/127.0.0.1/tcp/0/wss".parse().unwrap()).unwrap();
///
/// let addr = future::poll_fn(|cx| Pin::new(&mut transport).poll(cx)).await.into_new_address().unwrap();
/// println!("Listening on {addr}");
///
/// # }
/// ```
///
/// Plain Websocket transport:
///
/// ```
/// # use futures::future;
/// # use libp2p_core::{transport::ListenerId, Transport};
/// # use libp2p_dns as dns;
/// # use libp2p_tcp as tcp;
/// # use libp2p_websocket as websocket;
/// # use std::pin::Pin;
/// #
/// # #[async_std::main]
/// # async fn main() {
///
/// let mut transport = websocket::WsConfig::new(
///     tcp::async_io::Transport::new(tcp::Config::default()),
/// );
///
/// let id = transport.listen_on(ListenerId::next(), "/ip4/127.0.0.1/tcp/0/ws".parse().unwrap()).unwrap();
///
/// let addr = future::poll_fn(|cx| Pin::new(&mut transport).poll(cx)).await.into_new_address().unwrap();
/// println!("Listening on {addr}");
///
/// # }
/// ```
#[derive(Debug)]
pub struct WsConfig<T: Transport>
where
    T: Transport,
    T::Output: AsyncRead + AsyncWrite + Send + Unpin + 'static,
{
    transport: libp2p_core::transport::map::Map<framed::WsConfig<T>, WrapperFn<T::Output>>,
}

impl<T: Transport> WsConfig<T>
where
    T: Transport + Send + Unpin + 'static,
    T::Error: Send + 'static,
    T::Dial: Send + 'static,
    T::ListenerUpgrade: Send + 'static,
    T::Output: AsyncRead + AsyncWrite + Send + Unpin + 'static,
{
    /// Create a new websocket transport based on the given transport.
    ///
    /// > **Note*: The given transport must be based on TCP/IP and should
    /// > usually incorporate DNS resolution, though the latter is not
    /// > strictly necessary if one wishes to only use the `Ws` protocol
    /// > with known IP addresses and ports. See [`libp2p-tcp`](https://docs.rs/libp2p-tcp/)
    /// > and [`libp2p-dns`](https://docs.rs/libp2p-dns) for constructing
    /// > the inner transport.
    pub fn new(transport: T) -> Self {
        Self {
            transport: framed::WsConfig::new(transport)
                .map(wrap_connection as WrapperFn<T::Output>),
        }
    }

    /// Return the configured maximum number of redirects.
    pub fn max_redirects(&self) -> u8 {
        self.transport.inner().max_redirects()
    }

    /// Set max. number of redirects to follow.
    pub fn set_max_redirects(&mut self, max: u8) -> &mut Self {
        self.transport.inner_mut().set_max_redirects(max);
        self
    }

    /// Get the max. frame data size we support.
    pub fn max_data_size(&self) -> usize {
        self.transport.inner().max_data_size()
    }

    /// Set the max. frame data size we support.
    pub fn set_max_data_size(&mut self, size: usize) -> &mut Self {
        self.transport.inner_mut().set_max_data_size(size);
        self
    }

    /// Set the TLS configuration if TLS support is desired.
    pub fn set_tls_config(&mut self, c: tls::Config) -> &mut Self {
        self.transport.inner_mut().set_tls_config(c);
        self
    }
}

impl<T> Transport for WsConfig<T>
where
    T: Transport + Send + Unpin + 'static,
    T::Error: Send + 'static,
    T::Dial: Send + 'static,
    T::ListenerUpgrade: Send + 'static,
    T::Output: AsyncRead + AsyncWrite + Unpin + Send + 'static,
{
    type Output = RwStreamSink<BytesConnection<T::Output>>;
    type Error = Error<T::Error>;
    type ListenerUpgrade = MapFuture<InnerFuture<T::Output, T::Error>, WrapperFn<T::Output>>;
    type Dial = MapFuture<InnerFuture<T::Output, T::Error>, WrapperFn<T::Output>>;

    fn listen_on(
        &mut self,
        id: ListenerId,
        addr: Multiaddr,
    ) -> Result<(), TransportError<Self::Error>> {
        self.transport.listen_on(id, addr)
    }

    fn remove_listener(&mut self, id: ListenerId) -> bool {
        self.transport.remove_listener(id)
    }

    fn dial(&mut self, addr: Multiaddr) -> Result<Self::Dial, TransportError<Self::Error>> {
        self.transport.dial(addr)
    }

    fn dial_as_listener(
        &mut self,
        addr: Multiaddr,
    ) -> Result<Self::Dial, TransportError<Self::Error>> {
        self.transport.dial_as_listener(addr)
    }

    fn address_translation(&self, server: &Multiaddr, observed: &Multiaddr) -> Option<Multiaddr> {
        self.transport.address_translation(server, observed)
    }

    fn poll(
        mut self: Pin<&mut Self>,
        cx: &mut Context<'_>,
    ) -> Poll<TransportEvent<Self::ListenerUpgrade, Self::Error>> {
        Pin::new(&mut self.transport).poll(cx)
    }
}

/// Type alias corresponding to `framed::WsConfig::Dial` and `framed::WsConfig::ListenerUpgrade`.
pub type InnerFuture<T, E> = BoxFuture<'static, Result<Connection<T>, Error<E>>>;

/// Function type that wraps a websocket connection (see. `wrap_connection`).
pub type WrapperFn<T> = fn(Connection<T>, ConnectedPoint) -> RwStreamSink<BytesConnection<T>>;

/// Wrap a websocket connection producing data frames into a `RwStreamSink`
/// implementing `AsyncRead` + `AsyncWrite`.
fn wrap_connection<T>(c: Connection<T>, _: ConnectedPoint) -> RwStreamSink<BytesConnection<T>>
where
    T: AsyncRead + AsyncWrite + Send + Unpin + 'static,
{
    RwStreamSink::new(BytesConnection(c))
}

/// The websocket connection.
#[derive(Debug)]
pub struct BytesConnection<T>(Connection<T>);

impl<T> Stream for BytesConnection<T>
where
    T: AsyncRead + AsyncWrite + Send + Unpin + 'static,
{
    type Item = io::Result<Vec<u8>>;

    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
        loop {
            if let Some(item) = ready!(self.0.try_poll_next_unpin(cx)?) {
                if let Incoming::Data(payload) = item {
                    return Poll::Ready(Some(Ok(payload.into_bytes())));
                }
            } else {
                return Poll::Ready(None);
            }
        }
    }
}

impl<T> Sink<Vec<u8>> for BytesConnection<T>
where
    T: AsyncRead + AsyncWrite + Send + Unpin + 'static,
{
    type Error = io::Error;

    fn poll_ready(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
        Pin::new(&mut self.0).poll_ready(cx)
    }

    fn start_send(mut self: Pin<&mut Self>, item: Vec<u8>) -> io::Result<()> {
        Pin::new(&mut self.0).start_send(framed::OutgoingData::Binary(item))
    }

    fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
        Pin::new(&mut self.0).poll_flush(cx)
    }

    fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
        Pin::new(&mut self.0).poll_close(cx)
    }
}

// Tests //////////////////////////////////////////////////////////////////////////////////////////

#[cfg(test)]
mod tests {
    use super::WsConfig;
    use futures::prelude::*;
    use libp2p_core::{multiaddr::Protocol, transport::ListenerId, Multiaddr, Transport};
    use libp2p_identity::PeerId;
    use libp2p_tcp as tcp;

    #[test]
    fn dialer_connects_to_listener_ipv4() {
        let a = "/ip4/127.0.0.1/tcp/0/ws".parse().unwrap();
        futures::executor::block_on(connect(a))
    }

    #[test]
    fn dialer_connects_to_listener_ipv6() {
        let a = "/ip6/::1/tcp/0/ws".parse().unwrap();
        futures::executor::block_on(connect(a))
    }

    fn new_ws_config() -> WsConfig<tcp::async_io::Transport> {
        WsConfig::new(tcp::async_io::Transport::new(tcp::Config::default()))
    }

    async fn connect(listen_addr: Multiaddr) {
        let mut ws_config = new_ws_config().boxed();
        ws_config
            .listen_on(ListenerId::next(), listen_addr)
            .expect("listener");

        let addr = ws_config
            .next()
            .await
            .expect("no error")
            .into_new_address()
            .expect("listen address");

        assert_eq!(Some(Protocol::Ws("/".into())), addr.iter().nth(2));
        assert_ne!(Some(Protocol::Tcp(0)), addr.iter().nth(1));

        let inbound = async move {
            let (conn, _addr) = ws_config
                .select_next_some()
                .map(|ev| ev.into_incoming())
                .await
                .unwrap();
            conn.await
        };

        let outbound = new_ws_config()
            .boxed()
            .dial(addr.with(Protocol::P2p(PeerId::random())))
            .unwrap();

        let (a, b) = futures::join!(inbound, outbound);
        a.and(b).unwrap();
    }
}