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[rust-lightning] / lightning-net-tokio / src / lib.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
8 // licenses.
9
10 //! A socket handling library for those running in Tokio environments who wish to use
11 //! rust-lightning with native TcpStreams.
12 //!
13 //! Designed to be as simple as possible, the high-level usage is almost as simple as "hand over a
14 //! TcpStream and a reference to a PeerManager and the rest is handled", except for the
15 //! [Event](../lightning/util/events/enum.Event.html) handling mechanism; see example below.
16 //!
17 //! The PeerHandler, due to the fire-and-forget nature of this logic, must be an Arc, and must use
18 //! the SocketDescriptor provided here as the PeerHandler's SocketDescriptor.
19 //!
20 //! Three methods are exposed to register a new connection for handling in tokio::spawn calls; see
21 //! their individual docs for details.
22 //!
23 //! # Example
24 //! ```
25 //! use std::net::TcpStream;
26 //! use bitcoin::secp256k1::PublicKey;
27 //! use lightning::util::events::{Event, EventHandler, EventsProvider};
28 //! use std::net::SocketAddr;
29 //! use std::sync::Arc;
30 //!
31 //! // Define concrete types for our high-level objects:
32 //! type TxBroadcaster = dyn lightning::chain::chaininterface::BroadcasterInterface + Send + Sync;
33 //! type FeeEstimator = dyn lightning::chain::chaininterface::FeeEstimator + Send + Sync;
34 //! type Logger = dyn lightning::util::logger::Logger + Send + Sync;
35 //! type NodeSigner = dyn lightning::chain::keysinterface::NodeSigner + Send + Sync;
36 //! type ChainAccess = dyn lightning::chain::Access + Send + Sync;
37 //! type ChainFilter = dyn lightning::chain::Filter + Send + Sync;
38 //! type DataPersister = dyn lightning::chain::chainmonitor::Persist<lightning::chain::keysinterface::InMemorySigner> + Send + Sync;
39 //! type ChainMonitor = lightning::chain::chainmonitor::ChainMonitor<lightning::chain::keysinterface::InMemorySigner, Arc<ChainFilter>, Arc<TxBroadcaster>, Arc<FeeEstimator>, Arc<Logger>, Arc<DataPersister>>;
40 //! type ChannelManager = Arc<lightning::ln::channelmanager::SimpleArcChannelManager<ChainMonitor, TxBroadcaster, FeeEstimator, Logger>>;
41 //! type PeerManager = Arc<lightning::ln::peer_handler::SimpleArcPeerManager<lightning_net_tokio::SocketDescriptor, ChainMonitor, TxBroadcaster, FeeEstimator, ChainAccess, Logger>>;
42 //!
43 //! // Connect to node with pubkey their_node_id at addr:
44 //! async fn connect_to_node(peer_manager: PeerManager, chain_monitor: Arc<ChainMonitor>, channel_manager: ChannelManager, their_node_id: PublicKey, addr: SocketAddr) {
45 //!     lightning_net_tokio::connect_outbound(peer_manager, their_node_id, addr).await;
46 //!     loop {
47 //!             let event_handler = |event: Event| {
48 //!                     // Handle the event!
49 //!             };
50 //!             channel_manager.await_persistable_update();
51 //!             channel_manager.process_pending_events(&event_handler);
52 //!             chain_monitor.process_pending_events(&event_handler);
53 //!     }
54 //! }
55 //!
56 //! // Begin reading from a newly accepted socket and talk to the peer:
57 //! async fn accept_socket(peer_manager: PeerManager, chain_monitor: Arc<ChainMonitor>, channel_manager: ChannelManager, socket: TcpStream) {
58 //!     lightning_net_tokio::setup_inbound(peer_manager, socket);
59 //!     loop {
60 //!             let event_handler = |event: Event| {
61 //!                     // Handle the event!
62 //!             };
63 //!             channel_manager.await_persistable_update();
64 //!             channel_manager.process_pending_events(&event_handler);
65 //!             chain_monitor.process_pending_events(&event_handler);
66 //!     }
67 //! }
68 //! ```
69
70 // Prefix these with `rustdoc::` when we update our MSRV to be >= 1.52 to remove warnings.
71 #![deny(broken_intra_doc_links)]
72 #![deny(private_intra_doc_links)]
73
74 #![deny(missing_docs)]
75 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
76
77 use bitcoin::secp256k1::PublicKey;
78
79 use tokio::net::TcpStream;
80 use tokio::{io, time};
81 use tokio::sync::mpsc;
82 use tokio::io::{AsyncReadExt, AsyncWrite, AsyncWriteExt};
83
84 use lightning::chain::keysinterface::NodeSigner;
85 use lightning::ln::peer_handler;
86 use lightning::ln::peer_handler::SocketDescriptor as LnSocketTrait;
87 use lightning::ln::peer_handler::CustomMessageHandler;
88 use lightning::ln::msgs::{ChannelMessageHandler, NetAddress, OnionMessageHandler, RoutingMessageHandler};
89 use lightning::util::logger::Logger;
90
91 use std::ops::Deref;
92 use std::task;
93 use std::net::SocketAddr;
94 use std::net::TcpStream as StdTcpStream;
95 use std::sync::{Arc, Mutex};
96 use std::sync::atomic::{AtomicU64, Ordering};
97 use std::time::Duration;
98 use std::hash::Hash;
99
100 static ID_COUNTER: AtomicU64 = AtomicU64::new(0);
101
102 /// Connection contains all our internal state for a connection - we hold a reference to the
103 /// Connection object (in an Arc<Mutex<>>) in each SocketDescriptor we create as well as in the
104 /// read future (which is returned by schedule_read).
105 struct Connection {
106         writer: Option<io::WriteHalf<TcpStream>>,
107         // Because our PeerManager is templated by user-provided types, and we can't (as far as I can
108         // tell) have a const RawWakerVTable built out of templated functions, we need some indirection
109         // between being woken up with write-ready and calling PeerManager::write_buffer_space_avail.
110         // This provides that indirection, with a Sender which gets handed to the PeerManager Arc on
111         // the schedule_read stack.
112         //
113         // An alternative (likely more effecient) approach would involve creating a RawWakerVTable at
114         // runtime with functions templated by the Arc<PeerManager> type, calling
115         // write_buffer_space_avail directly from tokio's write wake, however doing so would require
116         // more unsafe voodo than I really feel like writing.
117         write_avail: mpsc::Sender<()>,
118         // When we are told by rust-lightning to pause read (because we have writes backing up), we do
119         // so by setting read_paused. At that point, the read task will stop reading bytes from the
120         // socket. To wake it up (without otherwise changing its state, we can push a value into this
121         // Sender.
122         read_waker: mpsc::Sender<()>,
123         read_paused: bool,
124         rl_requested_disconnect: bool,
125         id: u64,
126 }
127 impl Connection {
128         async fn poll_event_process<PM, CMH, RMH, OMH, L, UMH, NS>(
129                 peer_manager: PM,
130                 mut event_receiver: mpsc::Receiver<()>,
131         ) where
132                         PM: Deref<Target = peer_handler::PeerManager<SocketDescriptor, CMH, RMH, OMH, L, UMH, NS>> + 'static + Send + Sync,
133                         CMH: Deref + 'static + Send + Sync,
134                         RMH: Deref + 'static + Send + Sync,
135                         OMH: Deref + 'static + Send + Sync,
136                         L: Deref + 'static + Send + Sync,
137                         UMH: Deref + 'static + Send + Sync,
138                         NS: Deref + 'static + Send + Sync,
139                         CMH::Target: ChannelMessageHandler + Send + Sync,
140                         RMH::Target: RoutingMessageHandler + Send + Sync,
141                         OMH::Target: OnionMessageHandler + Send + Sync,
142                         L::Target: Logger + Send + Sync,
143                         UMH::Target: CustomMessageHandler + Send + Sync,
144                         NS::Target: NodeSigner + Send + Sync,
145         {
146                 loop {
147                         if event_receiver.recv().await.is_none() {
148                                 return;
149                         }
150                         peer_manager.process_events();
151                 }
152         }
153
154         async fn schedule_read<PM, CMH, RMH, OMH, L, UMH, NS>(
155                 peer_manager: PM,
156                 us: Arc<Mutex<Self>>,
157                 mut reader: io::ReadHalf<TcpStream>,
158                 mut read_wake_receiver: mpsc::Receiver<()>,
159                 mut write_avail_receiver: mpsc::Receiver<()>,
160         ) where
161                         PM: Deref<Target = peer_handler::PeerManager<SocketDescriptor, CMH, RMH, OMH, L, UMH, NS>> + 'static + Send + Sync + Clone,
162                         CMH: Deref + 'static + Send + Sync,
163                         RMH: Deref + 'static + Send + Sync,
164                         OMH: Deref + 'static + Send + Sync,
165                         L: Deref + 'static + Send + Sync,
166                         UMH: Deref + 'static + Send + Sync,
167                         NS: Deref + 'static + Send + Sync,
168                         CMH::Target: ChannelMessageHandler + 'static + Send + Sync,
169                         RMH::Target: RoutingMessageHandler + 'static + Send + Sync,
170                         OMH::Target: OnionMessageHandler + 'static + Send + Sync,
171                         L::Target: Logger + 'static + Send + Sync,
172                         UMH::Target: CustomMessageHandler + 'static + Send + Sync,
173                         NS::Target: NodeSigner + 'static + Send + Sync,
174                 {
175                 // Create a waker to wake up poll_event_process, above
176                 let (event_waker, event_receiver) = mpsc::channel(1);
177                 tokio::spawn(Self::poll_event_process(peer_manager.clone(), event_receiver));
178
179                 // 8KB is nice and big but also should never cause any issues with stack overflowing.
180                 let mut buf = [0; 8192];
181
182                 let mut our_descriptor = SocketDescriptor::new(us.clone());
183                 // An enum describing why we did/are disconnecting:
184                 enum Disconnect {
185                         // Rust-Lightning told us to disconnect, either by returning an Err or by calling
186                         // SocketDescriptor::disconnect_socket.
187                         // In this case, we do not call peer_manager.socket_disconnected() as Rust-Lightning
188                         // already knows we're disconnected.
189                         CloseConnection,
190                         // The connection was disconnected for some other reason, ie because the socket was
191                         // closed.
192                         // In this case, we do need to call peer_manager.socket_disconnected() to inform
193                         // Rust-Lightning that the socket is gone.
194                         PeerDisconnected
195                 }
196                 let disconnect_type = loop {
197                         let read_paused = {
198                                 let us_lock = us.lock().unwrap();
199                                 if us_lock.rl_requested_disconnect {
200                                         break Disconnect::CloseConnection;
201                                 }
202                                 us_lock.read_paused
203                         };
204                         tokio::select! {
205                                 v = write_avail_receiver.recv() => {
206                                         assert!(v.is_some()); // We can't have dropped the sending end, its in the us Arc!
207                                         if let Err(_) = peer_manager.write_buffer_space_avail(&mut our_descriptor) {
208                                                 break Disconnect::CloseConnection;
209                                         }
210                                 },
211                                 _ = read_wake_receiver.recv() => {},
212                                 read = reader.read(&mut buf), if !read_paused => match read {
213                                         Ok(0) => break Disconnect::PeerDisconnected,
214                                         Ok(len) => {
215                                                 let read_res = peer_manager.read_event(&mut our_descriptor, &buf[0..len]);
216                                                 let mut us_lock = us.lock().unwrap();
217                                                 match read_res {
218                                                         Ok(pause_read) => {
219                                                                 if pause_read {
220                                                                         us_lock.read_paused = true;
221                                                                 }
222                                                         },
223                                                         Err(_) => break Disconnect::CloseConnection,
224                                                 }
225                                         },
226                                         Err(_) => break Disconnect::PeerDisconnected,
227                                 },
228                         }
229                         let _ = event_waker.try_send(());
230
231                         // At this point we've processed a message or two, and reset the ping timer for this
232                         // peer, at least in the "are we still receiving messages" context, if we don't give up
233                         // our timeslice to another task we may just spin on this peer, starving other peers
234                         // and eventually disconnecting them for ping timeouts. Instead, we explicitly yield
235                         // here.
236                         tokio::task::yield_now().await;
237                 };
238                 let writer_option = us.lock().unwrap().writer.take();
239                 if let Some(mut writer) = writer_option {
240                         // If the socket is already closed, shutdown() will fail, so just ignore it.
241                         let _ = writer.shutdown().await;
242                 }
243                 if let Disconnect::PeerDisconnected = disconnect_type {
244                         peer_manager.socket_disconnected(&our_descriptor);
245                         peer_manager.process_events();
246                 }
247         }
248
249         fn new(stream: StdTcpStream) -> (io::ReadHalf<TcpStream>, mpsc::Receiver<()>, mpsc::Receiver<()>, Arc<Mutex<Self>>) {
250                 // We only ever need a channel of depth 1 here: if we returned a non-full write to the
251                 // PeerManager, we will eventually get notified that there is room in the socket to write
252                 // new bytes, which will generate an event. That event will be popped off the queue before
253                 // we call write_buffer_space_avail, ensuring that we have room to push a new () if, during
254                 // the write_buffer_space_avail() call, send_data() returns a non-full write.
255                 let (write_avail, write_receiver) = mpsc::channel(1);
256                 // Similarly here - our only goal is to make sure the reader wakes up at some point after
257                 // we shove a value into the channel which comes after we've reset the read_paused bool to
258                 // false.
259                 let (read_waker, read_receiver) = mpsc::channel(1);
260                 stream.set_nonblocking(true).unwrap();
261                 let (reader, writer) = io::split(TcpStream::from_std(stream).unwrap());
262
263                 (reader, write_receiver, read_receiver,
264                 Arc::new(Mutex::new(Self {
265                         writer: Some(writer), write_avail, read_waker, read_paused: false,
266                         rl_requested_disconnect: false,
267                         id: ID_COUNTER.fetch_add(1, Ordering::AcqRel)
268                 })))
269         }
270 }
271
272 fn get_addr_from_stream(stream: &StdTcpStream) -> Option<NetAddress> {
273         match stream.peer_addr() {
274                 Ok(SocketAddr::V4(sockaddr)) => Some(NetAddress::IPv4 {
275                         addr: sockaddr.ip().octets(),
276                         port: sockaddr.port(),
277                 }),
278                 Ok(SocketAddr::V6(sockaddr)) => Some(NetAddress::IPv6 {
279                         addr: sockaddr.ip().octets(),
280                         port: sockaddr.port(),
281                 }),
282                 Err(_) => None,
283         }
284 }
285
286 /// Process incoming messages and feed outgoing messages on the provided socket generated by
287 /// accepting an incoming connection.
288 ///
289 /// The returned future will complete when the peer is disconnected and associated handling
290 /// futures are freed, though, because all processing futures are spawned with tokio::spawn, you do
291 /// not need to poll the provided future in order to make progress.
292 pub fn setup_inbound<PM, CMH, RMH, OMH, L, UMH, NS>(
293         peer_manager: PM,
294         stream: StdTcpStream,
295 ) -> impl std::future::Future<Output=()> where
296                 PM: Deref<Target = peer_handler::PeerManager<SocketDescriptor, CMH, RMH, OMH, L, UMH, NS>> + 'static + Send + Sync + Clone,
297                 CMH: Deref + 'static + Send + Sync,
298                 RMH: Deref + 'static + Send + Sync,
299                 OMH: Deref + 'static + Send + Sync,
300                 L: Deref + 'static + Send + Sync,
301                 UMH: Deref + 'static + Send + Sync,
302                 NS: Deref + 'static + Send + Sync,
303                 CMH::Target: ChannelMessageHandler + Send + Sync,
304                 RMH::Target: RoutingMessageHandler + Send + Sync,
305                 OMH::Target: OnionMessageHandler + Send + Sync,
306                 L::Target: Logger + Send + Sync,
307                 UMH::Target: CustomMessageHandler + Send + Sync,
308                 NS::Target: NodeSigner + Send + Sync,
309 {
310         let remote_addr = get_addr_from_stream(&stream);
311         let (reader, write_receiver, read_receiver, us) = Connection::new(stream);
312         #[cfg(test)]
313         let last_us = Arc::clone(&us);
314
315         let handle_opt = if let Ok(_) = peer_manager.new_inbound_connection(SocketDescriptor::new(us.clone()), remote_addr) {
316                 Some(tokio::spawn(Connection::schedule_read(peer_manager, us, reader, read_receiver, write_receiver)))
317         } else {
318                 // Note that we will skip socket_disconnected here, in accordance with the PeerManager
319                 // requirements.
320                 None
321         };
322
323         async move {
324                 if let Some(handle) = handle_opt {
325                         if let Err(e) = handle.await {
326                                 assert!(e.is_cancelled());
327                         } else {
328                                 // This is certainly not guaranteed to always be true - the read loop may exit
329                                 // while there are still pending write wakers that need to be woken up after the
330                                 // socket shutdown(). Still, as a check during testing, to make sure tokio doesn't
331                                 // keep too many wakers around, this makes sense. The race should be rare (we do
332                                 // some work after shutdown()) and an error would be a major memory leak.
333                                 #[cfg(test)]
334                                 debug_assert!(Arc::try_unwrap(last_us).is_ok());
335                         }
336                 }
337         }
338 }
339
340 /// Process incoming messages and feed outgoing messages on the provided socket generated by
341 /// making an outbound connection which is expected to be accepted by a peer with the given
342 /// public key. The relevant processing is set to run free (via tokio::spawn).
343 ///
344 /// The returned future will complete when the peer is disconnected and associated handling
345 /// futures are freed, though, because all processing futures are spawned with tokio::spawn, you do
346 /// not need to poll the provided future in order to make progress.
347 pub fn setup_outbound<PM, CMH, RMH, OMH, L, UMH, NS>(
348         peer_manager: PM,
349         their_node_id: PublicKey,
350         stream: StdTcpStream,
351 ) -> impl std::future::Future<Output=()> where
352                 PM: Deref<Target = peer_handler::PeerManager<SocketDescriptor, CMH, RMH, OMH, L, UMH, NS>> + 'static + Send + Sync + Clone,
353                 CMH: Deref + 'static + Send + Sync,
354                 RMH: Deref + 'static + Send + Sync,
355                 OMH: Deref + 'static + Send + Sync,
356                 L: Deref + 'static + Send + Sync,
357                 UMH: Deref + 'static + Send + Sync,
358                 NS: Deref + 'static + Send + Sync,
359                 CMH::Target: ChannelMessageHandler + Send + Sync,
360                 RMH::Target: RoutingMessageHandler + Send + Sync,
361                 OMH::Target: OnionMessageHandler + Send + Sync,
362                 L::Target: Logger + Send + Sync,
363                 UMH::Target: CustomMessageHandler + Send + Sync,
364                 NS::Target: NodeSigner + Send + Sync,
365 {
366         let remote_addr = get_addr_from_stream(&stream);
367         let (reader, mut write_receiver, read_receiver, us) = Connection::new(stream);
368         #[cfg(test)]
369         let last_us = Arc::clone(&us);
370         let handle_opt = if let Ok(initial_send) = peer_manager.new_outbound_connection(their_node_id, SocketDescriptor::new(us.clone()), remote_addr) {
371                 Some(tokio::spawn(async move {
372                         // We should essentially always have enough room in a TCP socket buffer to send the
373                         // initial 10s of bytes. However, tokio running in single-threaded mode will always
374                         // fail writes and wake us back up later to write. Thus, we handle a single
375                         // std::task::Poll::Pending but still expect to write the full set of bytes at once
376                         // and use a relatively tight timeout.
377                         if let Ok(Ok(())) = tokio::time::timeout(Duration::from_millis(100), async {
378                                 loop {
379                                         match SocketDescriptor::new(us.clone()).send_data(&initial_send, true) {
380                                                 v if v == initial_send.len() => break Ok(()),
381                                                 0 => {
382                                                         write_receiver.recv().await;
383                                                         // In theory we could check for if we've been instructed to disconnect
384                                                         // the peer here, but its OK to just skip it - we'll check for it in
385                                                         // schedule_read prior to any relevant calls into RL.
386                                                 },
387                                                 _ => {
388                                                         eprintln!("Failed to write first full message to socket!");
389                                                         peer_manager.socket_disconnected(&SocketDescriptor::new(Arc::clone(&us)));
390                                                         break Err(());
391                                                 }
392                                         }
393                                 }
394                         }).await {
395                                 Connection::schedule_read(peer_manager, us, reader, read_receiver, write_receiver).await;
396                         }
397                 }))
398         } else {
399                 // Note that we will skip socket_disconnected here, in accordance with the PeerManager
400                 // requirements.
401                 None
402         };
403
404         async move {
405                 if let Some(handle) = handle_opt {
406                         if let Err(e) = handle.await {
407                                 assert!(e.is_cancelled());
408                         } else {
409                                 // This is certainly not guaranteed to always be true - the read loop may exit
410                                 // while there are still pending write wakers that need to be woken up after the
411                                 // socket shutdown(). Still, as a check during testing, to make sure tokio doesn't
412                                 // keep too many wakers around, this makes sense. The race should be rare (we do
413                                 // some work after shutdown()) and an error would be a major memory leak.
414                                 #[cfg(test)]
415                                 debug_assert!(Arc::try_unwrap(last_us).is_ok());
416                         }
417                 }
418         }
419 }
420
421 /// Process incoming messages and feed outgoing messages on a new connection made to the given
422 /// socket address which is expected to be accepted by a peer with the given public key (by
423 /// scheduling futures with tokio::spawn).
424 ///
425 /// Shorthand for TcpStream::connect(addr) with a timeout followed by setup_outbound().
426 ///
427 /// Returns a future (as the fn is async) which needs to be polled to complete the connection and
428 /// connection setup. That future then returns a future which will complete when the peer is
429 /// disconnected and associated handling futures are freed, though, because all processing in said
430 /// futures are spawned with tokio::spawn, you do not need to poll the second future in order to
431 /// make progress.
432 pub async fn connect_outbound<PM, CMH, RMH, OMH, L, UMH, NS>(
433         peer_manager: PM,
434         their_node_id: PublicKey,
435         addr: SocketAddr,
436 ) -> Option<impl std::future::Future<Output=()>> where
437                 PM: Deref<Target = peer_handler::PeerManager<SocketDescriptor, CMH, RMH, OMH, L, UMH, NS>> + 'static + Send + Sync + Clone,
438                 CMH: Deref + 'static + Send + Sync,
439                 RMH: Deref + 'static + Send + Sync,
440                 OMH: Deref + 'static + Send + Sync,
441                 L: Deref + 'static + Send + Sync,
442                 UMH: Deref + 'static + Send + Sync,
443                 NS: Deref + 'static + Send + Sync,
444                 CMH::Target: ChannelMessageHandler + Send + Sync,
445                 RMH::Target: RoutingMessageHandler + Send + Sync,
446                 OMH::Target: OnionMessageHandler + Send + Sync,
447                 L::Target: Logger + Send + Sync,
448                 UMH::Target: CustomMessageHandler + Send + Sync,
449                 NS::Target: NodeSigner + Send + Sync,
450 {
451         if let Ok(Ok(stream)) = time::timeout(Duration::from_secs(10), async { TcpStream::connect(&addr).await.map(|s| s.into_std().unwrap()) }).await {
452                 Some(setup_outbound(peer_manager, their_node_id, stream))
453         } else { None }
454 }
455
456 const SOCK_WAKER_VTABLE: task::RawWakerVTable =
457         task::RawWakerVTable::new(clone_socket_waker, wake_socket_waker, wake_socket_waker_by_ref, drop_socket_waker);
458
459 fn clone_socket_waker(orig_ptr: *const ()) -> task::RawWaker {
460         write_avail_to_waker(orig_ptr as *const mpsc::Sender<()>)
461 }
462 // When waking, an error should be fine. Most likely we got two send_datas in a row, both of which
463 // failed to fully write, but we only need to call write_buffer_space_avail() once. Otherwise, the
464 // sending thread may have already gone away due to a socket close, in which case there's nothing
465 // to wake up anyway.
466 fn wake_socket_waker(orig_ptr: *const ()) {
467         let sender = unsafe { &mut *(orig_ptr as *mut mpsc::Sender<()>) };
468         let _ = sender.try_send(());
469         drop_socket_waker(orig_ptr);
470 }
471 fn wake_socket_waker_by_ref(orig_ptr: *const ()) {
472         let sender_ptr = orig_ptr as *const mpsc::Sender<()>;
473         let sender = unsafe { (*sender_ptr).clone() };
474         let _ = sender.try_send(());
475 }
476 fn drop_socket_waker(orig_ptr: *const ()) {
477         let _orig_box = unsafe { Box::from_raw(orig_ptr as *mut mpsc::Sender<()>) };
478         // _orig_box is now dropped
479 }
480 fn write_avail_to_waker(sender: *const mpsc::Sender<()>) -> task::RawWaker {
481         let new_box = Box::leak(Box::new(unsafe { (*sender).clone() }));
482         let new_ptr = new_box as *const mpsc::Sender<()>;
483         task::RawWaker::new(new_ptr as *const (), &SOCK_WAKER_VTABLE)
484 }
485
486 /// The SocketDescriptor used to refer to sockets by a PeerHandler. This is pub only as it is a
487 /// type in the template of PeerHandler.
488 pub struct SocketDescriptor {
489         conn: Arc<Mutex<Connection>>,
490         id: u64,
491 }
492 impl SocketDescriptor {
493         fn new(conn: Arc<Mutex<Connection>>) -> Self {
494                 let id = conn.lock().unwrap().id;
495                 Self { conn, id }
496         }
497 }
498 impl peer_handler::SocketDescriptor for SocketDescriptor {
499         fn send_data(&mut self, data: &[u8], resume_read: bool) -> usize {
500                 // To send data, we take a lock on our Connection to access the WriteHalf of the TcpStream,
501                 // writing to it if there's room in the kernel buffer, or otherwise create a new Waker with
502                 // a SocketDescriptor in it which can wake up the write_avail Sender, waking up the
503                 // processing future which will call write_buffer_space_avail and we'll end up back here.
504                 let mut us = self.conn.lock().unwrap();
505                 if us.writer.is_none() {
506                         // The writer gets take()n when it is time to shut down, so just fast-return 0 here.
507                         return 0;
508                 }
509
510                 if resume_read && us.read_paused {
511                         // The schedule_read future may go to lock up but end up getting woken up by there
512                         // being more room in the write buffer, dropping the other end of this Sender
513                         // before we get here, so we ignore any failures to wake it up.
514                         us.read_paused = false;
515                         let _ = us.read_waker.try_send(());
516                 }
517                 if data.is_empty() { return 0; }
518                 let waker = unsafe { task::Waker::from_raw(write_avail_to_waker(&us.write_avail)) };
519                 let mut ctx = task::Context::from_waker(&waker);
520                 let mut written_len = 0;
521                 loop {
522                         match std::pin::Pin::new(us.writer.as_mut().unwrap()).poll_write(&mut ctx, &data[written_len..]) {
523                                 task::Poll::Ready(Ok(res)) => {
524                                         // The tokio docs *seem* to indicate this can't happen, and I certainly don't
525                                         // know how to handle it if it does (cause it should be a Poll::Pending
526                                         // instead):
527                                         assert_ne!(res, 0);
528                                         written_len += res;
529                                         if written_len == data.len() { return written_len; }
530                                 },
531                                 task::Poll::Ready(Err(e)) => {
532                                         // The tokio docs *seem* to indicate this can't happen, and I certainly don't
533                                         // know how to handle it if it does (cause it should be a Poll::Pending
534                                         // instead):
535                                         assert_ne!(e.kind(), io::ErrorKind::WouldBlock);
536                                         // Probably we've already been closed, just return what we have and let the
537                                         // read thread handle closing logic.
538                                         return written_len;
539                                 },
540                                 task::Poll::Pending => {
541                                         // We're queued up for a write event now, but we need to make sure we also
542                                         // pause read given we're now waiting on the remote end to ACK (and in
543                                         // accordance with the send_data() docs).
544                                         us.read_paused = true;
545                                         // Further, to avoid any current pending read causing a `read_event` call, wake
546                                         // up the read_waker and restart its loop.
547                                         let _ = us.read_waker.try_send(());
548                                         return written_len;
549                                 },
550                         }
551                 }
552         }
553
554         fn disconnect_socket(&mut self) {
555                 let mut us = self.conn.lock().unwrap();
556                 us.rl_requested_disconnect = true;
557                 // Wake up the sending thread, assuming it is still alive
558                 let _ = us.write_avail.try_send(());
559         }
560 }
561 impl Clone for SocketDescriptor {
562         fn clone(&self) -> Self {
563                 Self {
564                         conn: Arc::clone(&self.conn),
565                         id: self.id,
566                 }
567         }
568 }
569 impl Eq for SocketDescriptor {}
570 impl PartialEq for SocketDescriptor {
571         fn eq(&self, o: &Self) -> bool {
572                 self.id == o.id
573         }
574 }
575 impl Hash for SocketDescriptor {
576         fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
577                 self.id.hash(state);
578         }
579 }
580
581 #[cfg(test)]
582 mod tests {
583         use lightning::ln::features::*;
584         use lightning::ln::msgs::*;
585         use lightning::ln::peer_handler::{MessageHandler, PeerManager};
586         use lightning::ln::features::NodeFeatures;
587         use lightning::util::events::*;
588         use lightning::util::test_utils::TestNodeSigner;
589         use bitcoin::secp256k1::{Secp256k1, SecretKey, PublicKey};
590
591         use tokio::sync::mpsc;
592
593         use std::mem;
594         use std::sync::atomic::{AtomicBool, Ordering};
595         use std::sync::{Arc, Mutex};
596         use std::time::Duration;
597
598         pub struct TestLogger();
599         impl lightning::util::logger::Logger for TestLogger {
600                 fn log(&self, record: &lightning::util::logger::Record) {
601                         println!("{:<5} [{} : {}, {}] {}", record.level.to_string(), record.module_path, record.file, record.line, record.args);
602                 }
603         }
604
605         struct MsgHandler{
606                 expected_pubkey: PublicKey,
607                 pubkey_connected: mpsc::Sender<()>,
608                 pubkey_disconnected: mpsc::Sender<()>,
609                 disconnected_flag: AtomicBool,
610                 msg_events: Mutex<Vec<MessageSendEvent>>,
611         }
612         impl RoutingMessageHandler for MsgHandler {
613                 fn handle_node_announcement(&self, _msg: &NodeAnnouncement) -> Result<bool, LightningError> { Ok(false) }
614                 fn handle_channel_announcement(&self, _msg: &ChannelAnnouncement) -> Result<bool, LightningError> { Ok(false) }
615                 fn handle_channel_update(&self, _msg: &ChannelUpdate) -> Result<bool, LightningError> { Ok(false) }
616                 fn get_next_channel_announcement(&self, _starting_point: u64) -> Option<(ChannelAnnouncement, Option<ChannelUpdate>, Option<ChannelUpdate>)> { None }
617                 fn get_next_node_announcement(&self, _starting_point: Option<&PublicKey>) -> Option<NodeAnnouncement> { None }
618                 fn peer_connected(&self, _their_node_id: &PublicKey, _init_msg: &Init) -> Result<(), ()> { Ok(()) }
619                 fn handle_reply_channel_range(&self, _their_node_id: &PublicKey, _msg: ReplyChannelRange) -> Result<(), LightningError> { Ok(()) }
620                 fn handle_reply_short_channel_ids_end(&self, _their_node_id: &PublicKey, _msg: ReplyShortChannelIdsEnd) -> Result<(), LightningError> { Ok(()) }
621                 fn handle_query_channel_range(&self, _their_node_id: &PublicKey, _msg: QueryChannelRange) -> Result<(), LightningError> { Ok(()) }
622                 fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: QueryShortChannelIds) -> Result<(), LightningError> { Ok(()) }
623                 fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
624                 fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures { InitFeatures::empty() }
625         }
626         impl ChannelMessageHandler for MsgHandler {
627                 fn handle_open_channel(&self, _their_node_id: &PublicKey, _msg: &OpenChannel) {}
628                 fn handle_accept_channel(&self, _their_node_id: &PublicKey, _msg: &AcceptChannel) {}
629                 fn handle_funding_created(&self, _their_node_id: &PublicKey, _msg: &FundingCreated) {}
630                 fn handle_funding_signed(&self, _their_node_id: &PublicKey, _msg: &FundingSigned) {}
631                 fn handle_channel_ready(&self, _their_node_id: &PublicKey, _msg: &ChannelReady) {}
632                 fn handle_shutdown(&self, _their_node_id: &PublicKey, _msg: &Shutdown) {}
633                 fn handle_closing_signed(&self, _their_node_id: &PublicKey, _msg: &ClosingSigned) {}
634                 fn handle_update_add_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateAddHTLC) {}
635                 fn handle_update_fulfill_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFulfillHTLC) {}
636                 fn handle_update_fail_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFailHTLC) {}
637                 fn handle_update_fail_malformed_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFailMalformedHTLC) {}
638                 fn handle_commitment_signed(&self, _their_node_id: &PublicKey, _msg: &CommitmentSigned) {}
639                 fn handle_revoke_and_ack(&self, _their_node_id: &PublicKey, _msg: &RevokeAndACK) {}
640                 fn handle_update_fee(&self, _their_node_id: &PublicKey, _msg: &UpdateFee) {}
641                 fn handle_announcement_signatures(&self, _their_node_id: &PublicKey, _msg: &AnnouncementSignatures) {}
642                 fn handle_channel_update(&self, _their_node_id: &PublicKey, _msg: &ChannelUpdate) {}
643                 fn peer_disconnected(&self, their_node_id: &PublicKey, _no_connection_possible: bool) {
644                         if *their_node_id == self.expected_pubkey {
645                                 self.disconnected_flag.store(true, Ordering::SeqCst);
646                                 self.pubkey_disconnected.clone().try_send(()).unwrap();
647                         }
648                 }
649                 fn peer_connected(&self, their_node_id: &PublicKey, _init_msg: &Init) -> Result<(), ()> {
650                         if *their_node_id == self.expected_pubkey {
651                                 self.pubkey_connected.clone().try_send(()).unwrap();
652                         }
653                         Ok(())
654                 }
655                 fn handle_channel_reestablish(&self, _their_node_id: &PublicKey, _msg: &ChannelReestablish) {}
656                 fn handle_error(&self, _their_node_id: &PublicKey, _msg: &ErrorMessage) {}
657                 fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
658                 fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures { InitFeatures::empty() }
659         }
660         impl MessageSendEventsProvider for MsgHandler {
661                 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {
662                         let mut ret = Vec::new();
663                         mem::swap(&mut *self.msg_events.lock().unwrap(), &mut ret);
664                         ret
665                 }
666         }
667
668         fn make_tcp_connection() -> (std::net::TcpStream, std::net::TcpStream) {
669                 if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9735") {
670                         (std::net::TcpStream::connect("127.0.0.1:9735").unwrap(), listener.accept().unwrap().0)
671                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:19735") {
672                         (std::net::TcpStream::connect("127.0.0.1:19735").unwrap(), listener.accept().unwrap().0)
673                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9997") {
674                         (std::net::TcpStream::connect("127.0.0.1:9997").unwrap(), listener.accept().unwrap().0)
675                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9998") {
676                         (std::net::TcpStream::connect("127.0.0.1:9998").unwrap(), listener.accept().unwrap().0)
677                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9999") {
678                         (std::net::TcpStream::connect("127.0.0.1:9999").unwrap(), listener.accept().unwrap().0)
679                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:46926") {
680                         (std::net::TcpStream::connect("127.0.0.1:46926").unwrap(), listener.accept().unwrap().0)
681                 } else { panic!("Failed to bind to v4 localhost on common ports"); }
682         }
683
684         async fn do_basic_connection_test() {
685                 let secp_ctx = Secp256k1::new();
686                 let a_key = SecretKey::from_slice(&[1; 32]).unwrap();
687                 let b_key = SecretKey::from_slice(&[1; 32]).unwrap();
688                 let a_pub = PublicKey::from_secret_key(&secp_ctx, &a_key);
689                 let b_pub = PublicKey::from_secret_key(&secp_ctx, &b_key);
690
691                 let (a_connected_sender, mut a_connected) = mpsc::channel(1);
692                 let (a_disconnected_sender, mut a_disconnected) = mpsc::channel(1);
693                 let a_handler = Arc::new(MsgHandler {
694                         expected_pubkey: b_pub,
695                         pubkey_connected: a_connected_sender,
696                         pubkey_disconnected: a_disconnected_sender,
697                         disconnected_flag: AtomicBool::new(false),
698                         msg_events: Mutex::new(Vec::new()),
699                 });
700                 let a_manager = Arc::new(PeerManager::new(MessageHandler {
701                         chan_handler: Arc::clone(&a_handler),
702                         route_handler: Arc::clone(&a_handler),
703                         onion_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
704                 }, 0, &[1; 32], Arc::new(TestLogger()), Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}), Arc::new(TestNodeSigner::new(a_key))));
705
706                 let (b_connected_sender, mut b_connected) = mpsc::channel(1);
707                 let (b_disconnected_sender, mut b_disconnected) = mpsc::channel(1);
708                 let b_handler = Arc::new(MsgHandler {
709                         expected_pubkey: a_pub,
710                         pubkey_connected: b_connected_sender,
711                         pubkey_disconnected: b_disconnected_sender,
712                         disconnected_flag: AtomicBool::new(false),
713                         msg_events: Mutex::new(Vec::new()),
714                 });
715                 let b_manager = Arc::new(PeerManager::new(MessageHandler {
716                         chan_handler: Arc::clone(&b_handler),
717                         route_handler: Arc::clone(&b_handler),
718                         onion_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
719                 }, 0, &[2; 32], Arc::new(TestLogger()), Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}), Arc::new(TestNodeSigner::new(b_key))));
720
721                 // We bind on localhost, hoping the environment is properly configured with a local
722                 // address. This may not always be the case in containers and the like, so if this test is
723                 // failing for you check that you have a loopback interface and it is configured with
724                 // 127.0.0.1.
725                 let (conn_a, conn_b) = make_tcp_connection();
726
727                 let fut_a = super::setup_outbound(Arc::clone(&a_manager), b_pub, conn_a);
728                 let fut_b = super::setup_inbound(b_manager, conn_b);
729
730                 tokio::time::timeout(Duration::from_secs(10), a_connected.recv()).await.unwrap();
731                 tokio::time::timeout(Duration::from_secs(1), b_connected.recv()).await.unwrap();
732
733                 a_handler.msg_events.lock().unwrap().push(MessageSendEvent::HandleError {
734                         node_id: b_pub, action: ErrorAction::DisconnectPeer { msg: None }
735                 });
736                 assert!(!a_handler.disconnected_flag.load(Ordering::SeqCst));
737                 assert!(!b_handler.disconnected_flag.load(Ordering::SeqCst));
738
739                 a_manager.process_events();
740                 tokio::time::timeout(Duration::from_secs(10), a_disconnected.recv()).await.unwrap();
741                 tokio::time::timeout(Duration::from_secs(1), b_disconnected.recv()).await.unwrap();
742                 assert!(a_handler.disconnected_flag.load(Ordering::SeqCst));
743                 assert!(b_handler.disconnected_flag.load(Ordering::SeqCst));
744
745                 fut_a.await;
746                 fut_b.await;
747         }
748
749         #[tokio::test(flavor = "multi_thread")]
750         async fn basic_threaded_connection_test() {
751                 do_basic_connection_test().await;
752         }
753
754         #[tokio::test]
755         async fn basic_unthreaded_connection_test() {
756                 do_basic_connection_test().await;
757         }
758
759         async fn race_disconnect_accept() {
760                 // Previously, if we handed an already-disconnected socket to `setup_inbound` we'd panic.
761                 // This attempts to find other similar races by opening connections and shutting them down
762                 // while connecting. Sadly in testing this did *not* reproduce the previous issue.
763                 let secp_ctx = Secp256k1::new();
764                 let a_key = SecretKey::from_slice(&[1; 32]).unwrap();
765                 let b_key = SecretKey::from_slice(&[2; 32]).unwrap();
766                 let b_pub = PublicKey::from_secret_key(&secp_ctx, &b_key);
767
768                 let a_manager = Arc::new(PeerManager::new(MessageHandler {
769                         chan_handler: Arc::new(lightning::ln::peer_handler::ErroringMessageHandler::new()),
770                         onion_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
771                         route_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
772                 }, 0, &[1; 32], Arc::new(TestLogger()), Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}), Arc::new(TestNodeSigner::new(a_key))));
773
774                 // Make two connections, one for an inbound and one for an outbound connection
775                 let conn_a = {
776                         let (conn_a, _) = make_tcp_connection();
777                         conn_a
778                 };
779                 let conn_b = {
780                         let (_, conn_b) = make_tcp_connection();
781                         conn_b
782                 };
783
784                 // Call connection setup inside new tokio tasks.
785                 let manager_reference = Arc::clone(&a_manager);
786                 tokio::spawn(async move {
787                         super::setup_inbound(manager_reference, conn_a).await
788                 });
789                 tokio::spawn(async move {
790                         super::setup_outbound(a_manager, b_pub, conn_b).await
791                 });
792         }
793
794         #[tokio::test(flavor = "multi_thread")]
795         async fn threaded_race_disconnect_accept() {
796                 race_disconnect_accept().await;
797         }
798
799         #[tokio::test]
800         async fn unthreaded_race_disconnect_accept() {
801                 race_disconnect_accept().await;
802         }
803 }