fuchsia_bluetooth/types/
channel.rs

1// Copyright 2020 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use fidl::endpoints::{ClientEnd, Proxy};
6use fidl_fuchsia_bluetooth as fidl_bt;
7use fidl_fuchsia_bluetooth_bredr as bredr;
8use fuchsia_async as fasync;
9use fuchsia_sync::Mutex;
10use futures::sink::Sink;
11use futures::stream::{FusedStream, Stream};
12use futures::{Future, TryFutureExt, ready};
13use log::{error, warn};
14use std::collections::VecDeque;
15use std::fmt;
16use std::pin::Pin;
17use std::sync::Arc;
18use std::task::{Context, Poll};
19
20use crate::error::Error;
21
22/// The Channel mode in use for a L2CAP channel.
23#[derive(PartialEq, Debug, Clone)]
24pub enum ChannelMode {
25    Basic,
26    EnhancedRetransmissionMode,
27    LeCreditBasedFlowControl,
28    EnhancedCreditBasedFlowControl,
29}
30
31impl fmt::Display for ChannelMode {
32    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
33        match self {
34            ChannelMode::Basic => write!(f, "Basic"),
35            ChannelMode::EnhancedRetransmissionMode => write!(f, "ERTM"),
36            ChannelMode::LeCreditBasedFlowControl => write!(f, "LE_Credit"),
37            ChannelMode::EnhancedCreditBasedFlowControl => write!(f, "Credit"),
38        }
39    }
40}
41
42pub enum A2dpDirection {
43    Normal,
44    Source,
45    Sink,
46}
47
48impl From<A2dpDirection> for bredr::A2dpDirectionPriority {
49    fn from(pri: A2dpDirection) -> Self {
50        match pri {
51            A2dpDirection::Normal => bredr::A2dpDirectionPriority::Normal,
52            A2dpDirection::Source => bredr::A2dpDirectionPriority::Source,
53            A2dpDirection::Sink => bredr::A2dpDirectionPriority::Sink,
54        }
55    }
56}
57
58impl TryFrom<fidl_bt::ChannelMode> for ChannelMode {
59    type Error = Error;
60    fn try_from(fidl: fidl_bt::ChannelMode) -> Result<Self, Error> {
61        match fidl {
62            fidl_bt::ChannelMode::Basic => Ok(ChannelMode::Basic),
63            fidl_bt::ChannelMode::EnhancedRetransmission => {
64                Ok(ChannelMode::EnhancedRetransmissionMode)
65            }
66            fidl_bt::ChannelMode::LeCreditBasedFlowControl => {
67                Ok(ChannelMode::LeCreditBasedFlowControl)
68            }
69            fidl_bt::ChannelMode::EnhancedCreditBasedFlowControl => {
70                Ok(ChannelMode::EnhancedCreditBasedFlowControl)
71            }
72            x => Err(Error::FailedConversion(format!("Unsupported channel mode type: {x:?}"))),
73        }
74    }
75}
76
77impl From<ChannelMode> for fidl_bt::ChannelMode {
78    fn from(x: ChannelMode) -> Self {
79        match x {
80            ChannelMode::Basic => fidl_bt::ChannelMode::Basic,
81            ChannelMode::EnhancedRetransmissionMode => fidl_bt::ChannelMode::EnhancedRetransmission,
82            ChannelMode::LeCreditBasedFlowControl => fidl_bt::ChannelMode::LeCreditBasedFlowControl,
83            ChannelMode::EnhancedCreditBasedFlowControl => {
84                fidl_bt::ChannelMode::EnhancedCreditBasedFlowControl
85            }
86        }
87    }
88}
89
90/// A data channel to a remote Peer. Channels are the primary data transfer mechanism for
91/// Bluetooth profiles and protocols.
92/// Channel currently implements Deref<Target = Socket> to easily access the underlying
93/// socket, and also implements AsyncWrite using a forwarding implementation.
94#[derive(Debug)]
95pub struct Channel {
96    socket: fasync::Socket,
97    mode: ChannelMode,
98    max_tx_size: usize,
99    flush_timeout: Arc<Mutex<Option<zx::MonotonicDuration>>>,
100    audio_direction_ext: Option<bredr::AudioDirectionExtProxy>,
101    l2cap_parameters_ext: Option<bredr::L2capParametersExtProxy>,
102    audio_offload_ext: Option<bredr::AudioOffloadExtProxy>,
103    terminated: bool,
104    send_buffer: VecDeque<Vec<u8>>,
105}
106
107impl Channel {
108    const MAX_QUEUED_PACKETS: usize = 32;
109    /// Attempt to make a Channel from a zircon socket and a Maximum TX size received out of band.
110    /// Returns Err(status) if there is an error.
111    pub fn from_socket(socket: zx::Socket, max_tx_size: usize) -> Result<Self, zx::Status> {
112        Ok(Self::from_socket_infallible(socket, max_tx_size))
113    }
114
115    /// Make a Channel from a zircon socket and a Maximum TX size received out of band.
116    pub fn from_socket_infallible(socket: zx::Socket, max_tx_size: usize) -> Self {
117        Channel {
118            socket: fasync::Socket::from_socket(socket),
119            mode: ChannelMode::Basic,
120            max_tx_size,
121            flush_timeout: Arc::new(Mutex::new(None)),
122            audio_direction_ext: None,
123            l2cap_parameters_ext: None,
124            audio_offload_ext: None,
125            terminated: false,
126            send_buffer: VecDeque::with_capacity(Self::MAX_QUEUED_PACKETS),
127        }
128    }
129
130    /// The default max tx size is the default MTU size for L2CAP minus the channel header content.
131    /// See the Bluetooth Core Specification, Vol 3, Part A, Sec 5.1
132    pub const DEFAULT_MAX_TX: usize = 672;
133
134    /// Makes a pair of channels which are connected to each other, used commonly for testing.
135    /// The max_tx_size is set to `Channel::DEFAULT_MAX_TX`.
136    pub fn create() -> (Self, Self) {
137        Self::create_with_max_tx(Self::DEFAULT_MAX_TX)
138    }
139
140    /// Make a pair of channels which are connected to each other, used commonly for testing.
141    /// The maximum transmittable unit is taken from `max_tx_size`.
142    pub fn create_with_max_tx(max_tx_size: usize) -> (Self, Self) {
143        let (remote, local) = zx::Socket::create_datagram();
144        (
145            Channel::from_socket(remote, max_tx_size).unwrap(),
146            Channel::from_socket(local, max_tx_size).unwrap(),
147        )
148    }
149
150    /// The maximum transmittable size of a packet, in bytes.
151    /// Trying to send packets larger than this may cause the channel to be closed.
152    pub fn max_tx_size(&self) -> usize {
153        self.max_tx_size
154    }
155
156    pub fn channel_mode(&self) -> &ChannelMode {
157        &self.mode
158    }
159
160    pub fn flush_timeout(&self) -> Option<zx::MonotonicDuration> {
161        self.flush_timeout.lock().clone()
162    }
163
164    /// Returns a future which will set the audio priority of the channel.
165    /// The future will return Err if setting the priority is not supported.
166    pub fn set_audio_priority(
167        &self,
168        dir: A2dpDirection,
169    ) -> impl Future<Output = Result<(), Error>> + use<> {
170        let proxy = self.audio_direction_ext.clone();
171        async move {
172            match proxy {
173                None => return Err(Error::profile("audio priority not supported")),
174                Some(proxy) => proxy
175                    .set_priority(dir.into())
176                    .await?
177                    .map_err(|e| Error::profile(format!("setting priority failed: {e:?}"))),
178            }
179        }
180    }
181
182    /// Attempt to set the flush timeout for this channel.
183    /// If the timeout is not already set within 1ms of `duration`, we attempt to set it using the
184    /// L2cap parameter extension.
185    /// `duration` can be infinite to set packets flushable without a timeout.
186    /// Returns a future that when polled will set the flush timeout and return the new timeout,
187    /// or return an error setting the parameter is not supported.
188    pub fn set_flush_timeout(
189        &self,
190        duration: Option<zx::MonotonicDuration>,
191    ) -> impl Future<Output = Result<Option<zx::MonotonicDuration>, Error>> + use<> {
192        let flush_timeout = self.flush_timeout.clone();
193        let current = self.flush_timeout.lock().clone();
194        let proxy = self.l2cap_parameters_ext.clone();
195        async move {
196            match (current, duration) {
197                (None, None) => return Ok(None),
198                (Some(old), Some(new)) if (old - new).into_millis().abs() < 2 => {
199                    return Ok(current);
200                }
201                _ => {}
202            };
203            let proxy =
204                proxy.ok_or_else(|| Error::profile("l2cap parameter changing not supported"))?;
205            let parameters = fidl_bt::ChannelParameters {
206                flush_timeout: duration.clone().map(zx::MonotonicDuration::into_nanos),
207                ..Default::default()
208            };
209            let new_params = proxy.request_parameters(&parameters).await?;
210            let new_timeout = new_params.flush_timeout.map(zx::MonotonicDuration::from_nanos);
211            *(flush_timeout.lock()) = new_timeout.clone();
212            Ok(new_timeout)
213        }
214    }
215
216    /// Get a copy of the Audio Offload Proxy for this channel, if it exists
217    pub fn audio_offload(&self) -> Option<bredr::AudioOffloadExtProxy> {
218        self.audio_offload_ext.clone()
219    }
220
221    pub fn closed<'a>(&'a self) -> impl Future<Output = Result<(), zx::Status>> + 'a {
222        let close_signals = zx::Signals::SOCKET_PEER_CLOSED;
223        let close_wait = fasync::OnSignals::new(&self.socket, close_signals);
224        close_wait.map_ok(|_o| ())
225    }
226
227    pub fn is_closed<'a>(&'a self) -> bool {
228        self.socket.is_closed()
229    }
230
231    /// Write to the channel.  This will return zx::Status::SHOULD_WAIT if the
232    /// the channel is too full.
233    /// Prefer using the channel via Sink for asynchronous operations.
234    // TODO(b/499061686): remove to prefer async write.
235    pub fn write(&self, bytes: &[u8]) -> Result<usize, zx::Status> {
236        self.socket.as_ref().write(bytes)
237    }
238}
239
240impl TryFrom<fidl_fuchsia_bluetooth_bredr::Channel> for Channel {
241    type Error = zx::Status;
242
243    fn try_from(fidl: bredr::Channel) -> Result<Self, Self::Error> {
244        let channel = match fidl.channel_mode.unwrap_or(fidl_bt::ChannelMode::Basic).try_into() {
245            Err(e) => {
246                warn!("Unsupported channel mode type: {e:?}");
247                return Err(zx::Status::INTERNAL);
248            }
249            Ok(c) => c,
250        };
251
252        Ok(Self {
253            socket: fasync::Socket::from_socket(fidl.socket.ok_or(zx::Status::INVALID_ARGS)?),
254            mode: channel,
255            max_tx_size: fidl.max_tx_sdu_size.ok_or(zx::Status::INVALID_ARGS)? as usize,
256            flush_timeout: Arc::new(Mutex::new(
257                fidl.flush_timeout.map(zx::MonotonicDuration::from_nanos),
258            )),
259            audio_direction_ext: fidl.ext_direction.map(|e| e.into_proxy()),
260            l2cap_parameters_ext: fidl.ext_l2cap.map(|e| e.into_proxy()),
261            audio_offload_ext: fidl.ext_audio_offload.map(|c| c.into_proxy()),
262            terminated: false,
263            send_buffer: VecDeque::with_capacity(Self::MAX_QUEUED_PACKETS),
264        })
265    }
266}
267
268impl TryFrom<Channel> for bredr::Channel {
269    type Error = Error;
270
271    fn try_from(channel: Channel) -> Result<Self, Self::Error> {
272        let socket = channel.socket.into_zx_socket();
273        let ext_direction = channel
274            .audio_direction_ext
275            .map(|proxy| {
276                let chan = proxy.into_channel()?;
277                Ok(ClientEnd::new(chan.into()))
278            })
279            .transpose()
280            .map_err(|_: bredr::AudioDirectionExtProxy| {
281                Error::profile("AudioDirection proxy in use")
282            })?;
283        let ext_l2cap = channel
284            .l2cap_parameters_ext
285            .map(|proxy| {
286                let chan = proxy.into_channel()?;
287                Ok(ClientEnd::new(chan.into()))
288            })
289            .transpose()
290            .map_err(|_: bredr::L2capParametersExtProxy| {
291                Error::profile("l2cap parameters proxy in use")
292            })?;
293        let ext_audio_offload = channel
294            .audio_offload_ext
295            .map(|proxy| {
296                let chan = proxy.into_channel()?;
297                Ok(ClientEnd::new(chan.into()))
298            })
299            .transpose()
300            .map_err(|_: bredr::AudioOffloadExtProxy| {
301                Error::profile("audio offload proxy in use")
302            })?;
303        let flush_timeout = channel.flush_timeout.lock().map(zx::MonotonicDuration::into_nanos);
304        Ok(bredr::Channel {
305            socket: Some(socket),
306            channel_mode: Some(channel.mode.into()),
307            max_tx_sdu_size: Some(channel.max_tx_size as u16),
308            ext_direction,
309            flush_timeout,
310            ext_l2cap,
311            ext_audio_offload,
312            ..Default::default()
313        })
314    }
315}
316
317impl Stream for Channel {
318    type Item = Result<Vec<u8>, zx::Status>;
319
320    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
321        if self.terminated {
322            panic!("Channel polled after terminated");
323        }
324
325        let mut res = Vec::<u8>::new();
326        loop {
327            break match self.socket.poll_datagram(cx, &mut res) {
328                // TODO(https://fxbug.dev/42072274): Sometimes sockets return spirious 0 byte packets when polled.
329                // Try again.
330                Poll::Ready(Ok(0)) => continue,
331                Poll::Ready(Ok(_size)) => Poll::Ready(Some(Ok(res))),
332                Poll::Ready(Err(zx::Status::PEER_CLOSED)) => {
333                    self.terminated = true;
334                    Poll::Ready(None)
335                }
336                Poll::Ready(Err(e)) => Poll::Ready(Some(Err(e))),
337                Poll::Pending => Poll::Pending,
338            };
339        }
340    }
341}
342
343impl FusedStream for Channel {
344    fn is_terminated(&self) -> bool {
345        self.terminated
346    }
347}
348
349// Trait implementations for Channel.
350
351impl Sink<Vec<u8>> for Channel {
352    type Error = zx::Status;
353
354    fn poll_ready(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
355        // Try to flush to make progress, but ignore pending results.
356        let _ = Sink::poll_flush(self.as_mut(), cx)?;
357
358        if self.send_buffer.len() >= Channel::MAX_QUEUED_PACKETS {
359            return Poll::Pending;
360        }
361        Poll::Ready(Ok(()))
362    }
363
364    fn start_send(self: Pin<&mut Self>, item: Vec<u8>) -> Result<(), Self::Error> {
365        self.get_mut().send_buffer.push_back(item);
366        Ok(())
367    }
368
369    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
370        let this = self.get_mut();
371        use futures::io::AsyncWrite;
372        while let Some(item) = this.send_buffer.front() {
373            let res = Pin::new(&mut this.socket).poll_write(cx, item).map_err(zx::Status::from);
374            match res {
375                Poll::Ready(Ok(size)) => {
376                    if size == item.len() {
377                        let _ = this.send_buffer.pop_front();
378                    } else {
379                        error!(
380                            "Partial write in Channel::Sink::poll_flush: wrote {} bytes of {} byte packet.",
381                            size,
382                            item.len()
383                        );
384                        let item = this.send_buffer.front_mut().unwrap();
385                        *item = item.split_off(size);
386                    }
387                }
388                Poll::Ready(Err(e)) => return Poll::Ready(Err(e)),
389                Poll::Pending => return Poll::Pending,
390            }
391        }
392        Pin::new(&mut this.socket).poll_flush(cx).map_err(zx::Status::from)
393    }
394
395    fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
396        ready!(Sink::poll_flush(self.as_mut(), cx))?;
397        let this = self.get_mut();
398        use futures::io::AsyncWrite as _;
399        Pin::new(&mut this.socket).poll_close(cx).map_err(zx::Status::from)
400    }
401}
402
403#[cfg(test)]
404mod tests {
405    use super::*;
406    use fidl::endpoints::create_request_stream;
407    use futures::{SinkExt, StreamExt};
408    use std::pin::pin;
409
410    #[test]
411    fn test_channel_create_and_write() {
412        let mut exec = fasync::TestExecutor::new();
413        let (mut recv, mut send) = Channel::create();
414
415        let heart: &[u8] = &[0xF0, 0x9F, 0x92, 0x96];
416        let mut send_fut = send.send(heart.to_vec());
417        assert!(exec.run_until_stalled(&mut send_fut).is_ready());
418
419        let mut recv_fut = recv.next();
420        match exec.run_until_stalled(&mut recv_fut) {
421            Poll::Ready(Some(Ok(bytes))) => {
422                assert_eq!(heart, &bytes);
423            }
424            x => panic!("Expected Some(Ok(bytes)) from the stream, got {x:?}"),
425        };
426    }
427
428    #[test]
429    fn test_channel_from_fidl() {
430        let _exec = fasync::TestExecutor::new();
431        let empty = bredr::Channel::default();
432        assert!(Channel::try_from(empty).is_err());
433
434        let (remote, _local) = zx::Socket::create_datagram();
435
436        let okay = bredr::Channel {
437            socket: Some(remote),
438            channel_mode: Some(fidl_bt::ChannelMode::Basic),
439            max_tx_sdu_size: Some(1004),
440            ..Default::default()
441        };
442
443        let chan = Channel::try_from(okay).expect("okay channel to be converted");
444
445        assert_eq!(1004, chan.max_tx_size());
446        assert_eq!(&ChannelMode::Basic, chan.channel_mode());
447    }
448
449    #[test]
450    fn test_channel_closed() {
451        let mut exec = fasync::TestExecutor::new();
452
453        let (recv, send) = Channel::create();
454
455        let closed_fut = recv.closed();
456        let mut closed_fut = pin!(closed_fut);
457
458        assert!(exec.run_until_stalled(&mut closed_fut).is_pending());
459        assert!(!recv.is_closed());
460
461        drop(send);
462
463        assert!(exec.run_until_stalled(&mut closed_fut).is_ready());
464        assert!(recv.is_closed());
465    }
466
467    #[test]
468    fn test_direction_ext() {
469        let mut exec = fasync::TestExecutor::new();
470
471        let (remote, _local) = zx::Socket::create_datagram();
472        let no_ext = bredr::Channel {
473            socket: Some(remote),
474            channel_mode: Some(fidl_bt::ChannelMode::Basic),
475            max_tx_sdu_size: Some(1004),
476            ..Default::default()
477        };
478        let channel = Channel::try_from(no_ext).unwrap();
479
480        assert!(
481            exec.run_singlethreaded(channel.set_audio_priority(A2dpDirection::Normal)).is_err()
482        );
483        assert!(exec.run_singlethreaded(channel.set_audio_priority(A2dpDirection::Sink)).is_err());
484
485        let (remote, _local) = zx::Socket::create_datagram();
486        let (client_end, mut direction_request_stream) =
487            create_request_stream::<bredr::AudioDirectionExtMarker>();
488        let ext = bredr::Channel {
489            socket: Some(remote),
490            channel_mode: Some(fidl_bt::ChannelMode::Basic),
491            max_tx_sdu_size: Some(1004),
492            ext_direction: Some(client_end),
493            ..Default::default()
494        };
495
496        let channel = Channel::try_from(ext).unwrap();
497
498        let audio_direction_fut = channel.set_audio_priority(A2dpDirection::Normal);
499        let mut audio_direction_fut = pin!(audio_direction_fut);
500
501        assert!(exec.run_until_stalled(&mut audio_direction_fut).is_pending());
502
503        match exec.run_until_stalled(&mut direction_request_stream.next()) {
504            Poll::Ready(Some(Ok(bredr::AudioDirectionExtRequest::SetPriority {
505                priority,
506                responder,
507            }))) => {
508                assert_eq!(bredr::A2dpDirectionPriority::Normal, priority);
509                responder.send(Ok(())).expect("response to send cleanly");
510            }
511            x => panic!("Expected a item to be ready on the request stream, got {:?}", x),
512        };
513
514        match exec.run_until_stalled(&mut audio_direction_fut) {
515            Poll::Ready(Ok(())) => {}
516            _x => panic!("Expected ok result from audio direction response"),
517        };
518
519        let audio_direction_fut = channel.set_audio_priority(A2dpDirection::Sink);
520        let mut audio_direction_fut = pin!(audio_direction_fut);
521
522        assert!(exec.run_until_stalled(&mut audio_direction_fut).is_pending());
523
524        match exec.run_until_stalled(&mut direction_request_stream.next()) {
525            Poll::Ready(Some(Ok(bredr::AudioDirectionExtRequest::SetPriority {
526                priority,
527                responder,
528            }))) => {
529                assert_eq!(bredr::A2dpDirectionPriority::Sink, priority);
530                responder
531                    .send(Err(fidl_fuchsia_bluetooth::ErrorCode::Failed))
532                    .expect("response to send cleanly");
533            }
534            x => panic!("Expected a item to be ready on the request stream, got {:?}", x),
535        };
536
537        match exec.run_until_stalled(&mut audio_direction_fut) {
538            Poll::Ready(Err(_)) => {}
539            _x => panic!("Expected error result from audio direction response"),
540        };
541    }
542
543    #[test]
544    fn test_flush_timeout() {
545        let mut exec = fasync::TestExecutor::new();
546
547        let (remote, _local) = zx::Socket::create_datagram();
548        let no_ext = bredr::Channel {
549            socket: Some(remote),
550            channel_mode: Some(fidl_bt::ChannelMode::Basic),
551            max_tx_sdu_size: Some(1004),
552            flush_timeout: Some(50_000_000), // 50 milliseconds
553            ..Default::default()
554        };
555        let channel = Channel::try_from(no_ext).unwrap();
556
557        assert_eq!(Some(zx::MonotonicDuration::from_millis(50)), channel.flush_timeout());
558
559        // Within 2 milliseconds, doesn't change.
560        let res = exec.run_singlethreaded(
561            channel.set_flush_timeout(Some(zx::MonotonicDuration::from_millis(49))),
562        );
563        assert_eq!(Some(zx::MonotonicDuration::from_millis(50)), res.expect("shouldn't error"));
564        let res = exec.run_singlethreaded(
565            channel.set_flush_timeout(Some(zx::MonotonicDuration::from_millis(51))),
566        );
567        assert_eq!(Some(zx::MonotonicDuration::from_millis(50)), res.expect("shouldn't error"));
568
569        assert!(
570            exec.run_singlethreaded(
571                channel.set_flush_timeout(Some(zx::MonotonicDuration::from_millis(200)))
572            )
573            .is_err()
574        );
575        assert!(exec.run_singlethreaded(channel.set_flush_timeout(None)).is_err());
576
577        let (remote, _local) = zx::Socket::create_datagram();
578        let (client_end, mut l2cap_request_stream) =
579            create_request_stream::<bredr::L2capParametersExtMarker>();
580        let ext = bredr::Channel {
581            socket: Some(remote),
582            channel_mode: Some(fidl_bt::ChannelMode::Basic),
583            max_tx_sdu_size: Some(1004),
584            flush_timeout: None,
585            ext_l2cap: Some(client_end),
586            ..Default::default()
587        };
588
589        let channel = Channel::try_from(ext).unwrap();
590
591        {
592            let flush_timeout_fut = channel.set_flush_timeout(None);
593            let mut flush_timeout_fut = pin!(flush_timeout_fut);
594
595            // Requesting no change returns right away with no change.
596            match exec.run_until_stalled(&mut flush_timeout_fut) {
597                Poll::Ready(Ok(None)) => {}
598                x => panic!("Expected no flush timeout to not stall, got {:?}", x),
599            }
600        }
601
602        let req_duration = zx::MonotonicDuration::from_millis(42);
603
604        {
605            let flush_timeout_fut = channel.set_flush_timeout(Some(req_duration));
606            let mut flush_timeout_fut = pin!(flush_timeout_fut);
607
608            assert!(exec.run_until_stalled(&mut flush_timeout_fut).is_pending());
609
610            match exec.run_until_stalled(&mut l2cap_request_stream.next()) {
611                Poll::Ready(Some(Ok(bredr::L2capParametersExtRequest::RequestParameters {
612                    request,
613                    responder,
614                }))) => {
615                    assert_eq!(Some(req_duration.into_nanos()), request.flush_timeout);
616                    // Send a different response
617                    let params = fidl_bt::ChannelParameters {
618                        flush_timeout: Some(50_000_000), // 50ms
619                        ..Default::default()
620                    };
621                    responder.send(&params).expect("response to send cleanly");
622                }
623                x => panic!("Expected a item to be ready on the request stream, got {:?}", x),
624            };
625
626            match exec.run_until_stalled(&mut flush_timeout_fut) {
627                Poll::Ready(Ok(Some(duration))) => {
628                    assert_eq!(zx::MonotonicDuration::from_millis(50), duration)
629                }
630                x => panic!("Expected ready result from params response, got {:?}", x),
631            };
632        }
633
634        // Channel should have recorded the new flush timeout.
635        assert_eq!(Some(zx::MonotonicDuration::from_millis(50)), channel.flush_timeout());
636    }
637
638    #[test]
639    fn test_audio_offload() {
640        let _exec = fasync::TestExecutor::new();
641
642        let (remote, _local) = zx::Socket::create_datagram();
643        let no_ext = bredr::Channel {
644            socket: Some(remote),
645            channel_mode: Some(fidl_bt::ChannelMode::Basic),
646            max_tx_sdu_size: Some(1004),
647            ..Default::default()
648        };
649        let channel = Channel::try_from(no_ext).unwrap();
650
651        assert!(channel.audio_offload().is_none());
652
653        let (remote, _local) = zx::Socket::create_datagram();
654        let (client_end, mut _audio_offload_ext_req_stream) =
655            create_request_stream::<bredr::AudioOffloadExtMarker>();
656        let ext = bredr::Channel {
657            socket: Some(remote),
658            channel_mode: Some(fidl_bt::ChannelMode::Basic),
659            max_tx_sdu_size: Some(1004),
660            ext_audio_offload: Some(client_end),
661            ..Default::default()
662        };
663
664        let channel = Channel::try_from(ext).unwrap();
665
666        let offload_ext = channel.audio_offload();
667        assert!(offload_ext.is_some());
668        // We can get the audio offload multiple times without dropping
669        assert!(channel.audio_offload().is_some());
670        // And with dropping
671        drop(offload_ext);
672        assert!(channel.audio_offload().is_some());
673    }
674
675    #[test]
676    fn channel_sink() {
677        let mut exec = fasync::TestExecutor::new();
678        let (mut recv, mut send) = Channel::create();
679
680        let data = vec![0x01, 0x02, 0x03, 0x04];
681        let mut send_fut = send.send(data.clone());
682
683        // The send should complete immediately as the socket has space.
684        match exec.run_until_stalled(&mut send_fut) {
685            Poll::Ready(Ok(())) => {}
686            x => panic!("Expected Ready(Ok(())), got {:?}", x),
687        }
688
689        let mut recv_fut = recv.next();
690        match exec.run_until_stalled(&mut recv_fut) {
691            Poll::Ready(Some(Ok(bytes))) => assert_eq!(data, bytes),
692            x => panic!("Expected successful read, got {x:?}"),
693        }
694    }
695
696    #[test]
697    fn channel_stream() {
698        let mut exec = fasync::TestExecutor::new();
699        let (mut recv, send) = Channel::create();
700
701        let mut stream_fut = recv.next();
702
703        assert!(exec.run_until_stalled(&mut stream_fut).is_pending());
704
705        let heart: &[u8] = &[0xF0, 0x9F, 0x92, 0x96];
706        assert_eq!(heart.len(), send.write(heart).expect("should write successfully"));
707
708        match exec.run_until_stalled(&mut stream_fut) {
709            Poll::Ready(Some(Ok(bytes))) => {
710                assert_eq!(heart.to_vec(), bytes);
711            }
712            x => panic!("Expected Some(Ok(bytes)) from the stream, got {x:?}"),
713        };
714
715        // After the sender is dropped, the stream should terminate.
716        drop(send);
717
718        let mut stream_fut = recv.next();
719        match exec.run_until_stalled(&mut stream_fut) {
720            Poll::Ready(None) => {}
721            x => panic!("Expected None from the stream after close, got {x:?}"),
722        }
723
724        // It should continue to report terminated.
725        assert!(recv.is_terminated());
726    }
727}
fuchsia_bluetooth/types/channel.rs

fuchsia_bluetooth/types/
channel.rs
