git.bitcoin.ninja Git - rust-lightning/blob - 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 [`TcpStream`]s.
  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".
  15 //!
  16 //! The [`PeerManager`], due to the fire-and-forget nature of this logic, must be a reference,
  17 //! (e.g. an [`Arc`]) and must use the [`SocketDescriptor`] provided here as the [`PeerManager`]'s
  18 //! `SocketDescriptor` implementation.
  19 //!
  20 //! Three methods are exposed to register a new connection for handling in [`tokio::spawn`] calls;
  21 //! see their individual docs for details.
  22 //!
  23 //! [`PeerManager`]: lightning::ln::peer_handler::PeerManager
  24
  25 #![deny(rustdoc::broken_intra_doc_links)]
  26 #![deny(rustdoc::private_intra_doc_links)]
  27
  28 #![deny(missing_docs)]
  29 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
  30
  31 use bitcoin::secp256k1::PublicKey;
  32
  33 use tokio::net::TcpStream;
  34 use tokio::time;
  35 use tokio::sync::mpsc;
  36
  37 use lightning::ln::peer_handler;
  38 use lightning::ln::peer_handler::SocketDescriptor as LnSocketTrait;
  39 use lightning::ln::peer_handler::APeerManager;
  40 use lightning::ln::msgs::SocketAddress;
  41
  42 use std::ops::Deref;
  43 use std::task::{self, Poll};
  44 use std::future::Future;
  45 use std::net::SocketAddr;
  46 use std::net::TcpStream as StdTcpStream;
  47 use std::sync::{Arc, Mutex};
  48 use std::sync::atomic::{AtomicU64, Ordering};
  49 use std::time::Duration;
  50 use std::pin::Pin;
  51 use std::hash::Hash;
  52
  53 static ID_COUNTER: AtomicU64 = AtomicU64::new(0);
  54
  55 // We only need to select over multiple futures in one place, and taking on the full `tokio/macros`
  56 // dependency tree in order to do so (which has broken our MSRV before) is excessive. Instead, we
  57 // define a trivial two- and three- select macro with the specific types we need and just use that.
  58
  59 pub(crate) enum SelectorOutput {
  60         A(Option<()>), B(Option<()>), C(tokio::io::Result<()>),
  61 }
  62
  63 pub(crate) struct TwoSelector<
  64         A: Future<Output=Option<()>> + Unpin, B: Future<Output=Option<()>> + Unpin
  65 > {
  66         pub a: A,
  67         pub b: B,
  68 }
  69
  70 impl<
  71         A: Future<Output=Option<()>> + Unpin, B: Future<Output=Option<()>> + Unpin
  72 > Future for TwoSelector<A, B> {
  73         type Output = SelectorOutput;
  74         fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<SelectorOutput> {
  75                 match Pin::new(&mut self.a).poll(ctx) {
  76                         Poll::Ready(res) => { return Poll::Ready(SelectorOutput::A(res)); },
  77                         Poll::Pending => {},
  78                 }
  79                 match Pin::new(&mut self.b).poll(ctx) {
  80                         Poll::Ready(res) => { return Poll::Ready(SelectorOutput::B(res)); },
  81                         Poll::Pending => {},
  82                 }
  83                 Poll::Pending
  84         }
  85 }
  86
  87 pub(crate) struct ThreeSelector<
  88         A: Future<Output=Option<()>> + Unpin, B: Future<Output=Option<()>> + Unpin, C: Future<Output=tokio::io::Result<()>> + Unpin
  89 > {
  90         pub a: A,
  91         pub b: B,
  92         pub c: C,
  93 }
  94
  95 impl<
  96         A: Future<Output=Option<()>> + Unpin, B: Future<Output=Option<()>> + Unpin, C: Future<Output=tokio::io::Result<()>> + Unpin
  97 > Future for ThreeSelector<A, B, C> {
  98         type Output = SelectorOutput;
  99         fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<SelectorOutput> {
 100                 match Pin::new(&mut self.a).poll(ctx) {
 101                         Poll::Ready(res) => { return Poll::Ready(SelectorOutput::A(res)); },
 102                         Poll::Pending => {},
 103                 }
 104                 match Pin::new(&mut self.b).poll(ctx) {
 105                         Poll::Ready(res) => { return Poll::Ready(SelectorOutput::B(res)); },
 106                         Poll::Pending => {},
 107                 }
 108                 match Pin::new(&mut self.c).poll(ctx) {
 109                         Poll::Ready(res) => { return Poll::Ready(SelectorOutput::C(res)); },
 110                         Poll::Pending => {},
 111                 }
 112                 Poll::Pending
 113         }
 114 }
 115
 116 /// Connection contains all our internal state for a connection - we hold a reference to the
 117 /// Connection object (in an Arc<Mutex<>>) in each SocketDescriptor we create as well as in the
 118 /// read future (which is returned by schedule_read).
 119 struct Connection {
 120         writer: Option<Arc<TcpStream>>,
 121         // Because our PeerManager is templated by user-provided types, and we can't (as far as I can
 122         // tell) have a const RawWakerVTable built out of templated functions, we need some indirection
 123         // between being woken up with write-ready and calling PeerManager::write_buffer_space_avail.
 124         // This provides that indirection, with a Sender which gets handed to the PeerManager Arc on
 125         // the schedule_read stack.
 126         //
 127         // An alternative (likely more effecient) approach would involve creating a RawWakerVTable at
 128         // runtime with functions templated by the Arc<PeerManager> type, calling
 129         // write_buffer_space_avail directly from tokio's write wake, however doing so would require
 130         // more unsafe voodo than I really feel like writing.
 131         write_avail: mpsc::Sender<()>,
 132         // When we are told by rust-lightning to pause read (because we have writes backing up), we do
 133         // so by setting read_paused. At that point, the read task will stop reading bytes from the
 134         // socket. To wake it up (without otherwise changing its state, we can push a value into this
 135         // Sender.
 136         read_waker: mpsc::Sender<()>,
 137         read_paused: bool,
 138         rl_requested_disconnect: bool,
 139         id: u64,
 140 }
 141 impl Connection {
 142         async fn poll_event_process<PM: Deref + 'static + Send + Sync>(
 143                 peer_manager: PM,
 144                 mut event_receiver: mpsc::Receiver<()>,
 145         ) where PM::Target: APeerManager<Descriptor = SocketDescriptor> {
 146                 loop {
 147                         if event_receiver.recv().await.is_none() {
 148                                 return;
 149                         }
 150                         peer_manager.as_ref().process_events();
 151                 }
 152         }
 153
 154         async fn schedule_read<PM: Deref + 'static + Send + Sync + Clone>(
 155                 peer_manager: PM,
 156                 us: Arc<Mutex<Self>>,
 157                 reader: Arc<TcpStream>,
 158                 mut read_wake_receiver: mpsc::Receiver<()>,
 159                 mut write_avail_receiver: mpsc::Receiver<()>,
 160         ) where PM::Target: APeerManager<Descriptor = SocketDescriptor> {
 161                 // Create a waker to wake up poll_event_process, above
 162                 let (event_waker, event_receiver) = mpsc::channel(1);
 163                 tokio::spawn(Self::poll_event_process(peer_manager.clone(), event_receiver));
 164
 165                 // 4KiB is nice and big without handling too many messages all at once, giving other peers
 166                 // a chance to do some work.
 167                 let mut buf = [0; 4096];
 168
 169                 let mut our_descriptor = SocketDescriptor::new(us.clone());
 170                 // An enum describing why we did/are disconnecting:
 171                 enum Disconnect {
 172                         // Rust-Lightning told us to disconnect, either by returning an Err or by calling
 173                         // SocketDescriptor::disconnect_socket.
 174                         // In this case, we do not call peer_manager.socket_disconnected() as Rust-Lightning
 175                         // already knows we're disconnected.
 176                         CloseConnection,
 177                         // The connection was disconnected for some other reason, ie because the socket was
 178                         // closed.
 179                         // In this case, we do need to call peer_manager.socket_disconnected() to inform
 180                         // Rust-Lightning that the socket is gone.
 181                         PeerDisconnected
 182                 }
 183                 let disconnect_type = loop {
 184                         let read_paused = {
 185                                 let us_lock = us.lock().unwrap();
 186                                 if us_lock.rl_requested_disconnect {
 187                                         break Disconnect::CloseConnection;
 188                                 }
 189                                 us_lock.read_paused
 190                         };
 191                         // TODO: Drop the Box'ing of the futures once Rust has pin-on-stack support.
 192                         let select_result = if read_paused {
 193                                 TwoSelector {
 194                                         a: Box::pin(write_avail_receiver.recv()),
 195                                         b: Box::pin(read_wake_receiver.recv()),
 196                                 }.await
 197                         } else {
 198                                 ThreeSelector {
 199                                         a: Box::pin(write_avail_receiver.recv()),
 200                                         b: Box::pin(read_wake_receiver.recv()),
 201                                         c: Box::pin(reader.readable()),
 202                                 }.await
 203                         };
 204                         match select_result {
 205                                 SelectorOutput::A(v) => {
 206                                         assert!(v.is_some()); // We can't have dropped the sending end, its in the us Arc!
 207                                         if peer_manager.as_ref().write_buffer_space_avail(&mut our_descriptor).is_err() {
 208                                                 break Disconnect::CloseConnection;
 209                                         }
 210                                 },
 211                                 SelectorOutput::B(_) => {},
 212                                 SelectorOutput::C(res) => {
 213                                         if res.is_err() { break Disconnect::PeerDisconnected; }
 214                                         match reader.try_read(&mut buf) {
 215                                                 Ok(0) => break Disconnect::PeerDisconnected,
 216                                                 Ok(len) => {
 217                                                         let read_res = peer_manager.as_ref().read_event(&mut our_descriptor, &buf[0..len]);
 218                                                         let mut us_lock = us.lock().unwrap();
 219                                                         match read_res {
 220                                                                 Ok(pause_read) => {
 221                                                                         if pause_read {
 222                                                                                 us_lock.read_paused = true;
 223                                                                         }
 224                                                                 },
 225                                                                 Err(_) => break Disconnect::CloseConnection,
 226                                                         }
 227                                                 },
 228                                                 Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
 229                                                         // readable() is allowed to spuriously wake, so we have to handle
 230                                                         // WouldBlock here.
 231                                                 },
 232                                                 Err(_) => break Disconnect::PeerDisconnected,
 233                                         }
 234                                 },
 235                         }
 236                         let _ = event_waker.try_send(());
 237
 238                         // At this point we've processed a message or two, and reset the ping timer for this
 239                         // peer, at least in the "are we still receiving messages" context, if we don't give up
 240                         // our timeslice to another task we may just spin on this peer, starving other peers
 241                         // and eventually disconnecting them for ping timeouts. Instead, we explicitly yield
 242                         // here.
 243                         let _ = tokio::task::yield_now().await;
 244                 };
 245                 us.lock().unwrap().writer.take();
 246                 if let Disconnect::PeerDisconnected = disconnect_type {
 247                         peer_manager.as_ref().socket_disconnected(&our_descriptor);
 248                         peer_manager.as_ref().process_events();
 249                 }
 250         }
 251
 252         fn new(stream: StdTcpStream) -> (Arc<TcpStream>, mpsc::Receiver<()>, mpsc::Receiver<()>, Arc<Mutex<Self>>) {
 253                 // We only ever need a channel of depth 1 here: if we returned a non-full write to the
 254                 // PeerManager, we will eventually get notified that there is room in the socket to write
 255                 // new bytes, which will generate an event. That event will be popped off the queue before
 256                 // we call write_buffer_space_avail, ensuring that we have room to push a new () if, during
 257                 // the write_buffer_space_avail() call, send_data() returns a non-full write.
 258                 let (write_avail, write_receiver) = mpsc::channel(1);
 259                 // Similarly here - our only goal is to make sure the reader wakes up at some point after
 260                 // we shove a value into the channel which comes after we've reset the read_paused bool to
 261                 // false.
 262                 let (read_waker, read_receiver) = mpsc::channel(1);
 263                 stream.set_nonblocking(true).unwrap();
 264                 let tokio_stream = Arc::new(TcpStream::from_std(stream).unwrap());
 265
 266                 (Arc::clone(&tokio_stream), write_receiver, read_receiver,
 267                 Arc::new(Mutex::new(Self {
 268                         writer: Some(tokio_stream), write_avail, read_waker, read_paused: false,
 269                         rl_requested_disconnect: false,
 270                         id: ID_COUNTER.fetch_add(1, Ordering::AcqRel)
 271                 })))
 272         }
 273 }
 274
 275 fn get_addr_from_stream(stream: &StdTcpStream) -> Option<SocketAddress> {
 276         match stream.peer_addr() {
 277                 Ok(SocketAddr::V4(sockaddr)) => Some(SocketAddress::TcpIpV4 {
 278                         addr: sockaddr.ip().octets(),
 279                         port: sockaddr.port(),
 280                 }),
 281                 Ok(SocketAddr::V6(sockaddr)) => Some(SocketAddress::TcpIpV6 {
 282                         addr: sockaddr.ip().octets(),
 283                         port: sockaddr.port(),
 284                 }),
 285                 Err(_) => None,
 286         }
 287 }
 288
 289 /// Process incoming messages and feed outgoing messages on the provided socket generated by
 290 /// accepting an incoming connection.
 291 ///
 292 /// The returned future will complete when the peer is disconnected and associated handling
 293 /// futures are freed, though, because all processing futures are spawned with tokio::spawn, you do
 294 /// not need to poll the provided future in order to make progress.
 295 pub fn setup_inbound<PM: Deref + 'static + Send + Sync + Clone>(
 296         peer_manager: PM,
 297         stream: StdTcpStream,
 298 ) -> impl std::future::Future<Output=()>
 299 where PM::Target: APeerManager<Descriptor = SocketDescriptor> {
 300         let remote_addr = get_addr_from_stream(&stream);
 301         let (reader, write_receiver, read_receiver, us) = Connection::new(stream);
 302         #[cfg(test)]
 303         let last_us = Arc::clone(&us);
 304
 305         let handle_opt = if peer_manager.as_ref().new_inbound_connection(SocketDescriptor::new(us.clone()), remote_addr).is_ok() {
 306                 Some(tokio::spawn(Connection::schedule_read(peer_manager, us, reader, read_receiver, write_receiver)))
 307         } else {
 308                 // Note that we will skip socket_disconnected here, in accordance with the PeerManager
 309                 // requirements.
 310                 None
 311         };
 312
 313         async move {
 314                 if let Some(handle) = handle_opt {
 315                         if let Err(e) = handle.await {
 316                                 assert!(e.is_cancelled());
 317                         } else {
 318                                 // This is certainly not guaranteed to always be true - the read loop may exit
 319                                 // while there are still pending write wakers that need to be woken up after the
 320                                 // socket shutdown(). Still, as a check during testing, to make sure tokio doesn't
 321                                 // keep too many wakers around, this makes sense. The race should be rare (we do
 322                                 // some work after shutdown()) and an error would be a major memory leak.
 323                                 #[cfg(test)]
 324                                 debug_assert!(Arc::try_unwrap(last_us).is_ok());
 325                         }
 326                 }
 327         }
 328 }
 329
 330 /// Process incoming messages and feed outgoing messages on the provided socket generated by
 331 /// making an outbound connection which is expected to be accepted by a peer with the given
 332 /// public key. The relevant processing is set to run free (via tokio::spawn).
 333 ///
 334 /// The returned future will complete when the peer is disconnected and associated handling
 335 /// futures are freed, though, because all processing futures are spawned with tokio::spawn, you do
 336 /// not need to poll the provided future in order to make progress.
 337 pub fn setup_outbound<PM: Deref + 'static + Send + Sync + Clone>(
 338         peer_manager: PM,
 339         their_node_id: PublicKey,
 340         stream: StdTcpStream,
 341 ) -> impl std::future::Future<Output=()>
 342 where PM::Target: APeerManager<Descriptor = SocketDescriptor> {
 343         let remote_addr = get_addr_from_stream(&stream);
 344         let (reader, mut write_receiver, read_receiver, us) = Connection::new(stream);
 345         #[cfg(test)]
 346         let last_us = Arc::clone(&us);
 347         let handle_opt = if let Ok(initial_send) = peer_manager.as_ref().new_outbound_connection(their_node_id, SocketDescriptor::new(us.clone()), remote_addr) {
 348                 Some(tokio::spawn(async move {
 349                         // We should essentially always have enough room in a TCP socket buffer to send the
 350                         // initial 10s of bytes. However, tokio running in single-threaded mode will always
 351                         // fail writes and wake us back up later to write. Thus, we handle a single
 352                         // std::task::Poll::Pending but still expect to write the full set of bytes at once
 353                         // and use a relatively tight timeout.
 354                         if let Ok(Ok(())) = tokio::time::timeout(Duration::from_millis(100), async {
 355                                 loop {
 356                                         match SocketDescriptor::new(us.clone()).send_data(&initial_send, true) {
 357                                                 v if v == initial_send.len() => break Ok(()),
 358                                                 0 => {
 359                                                         write_receiver.recv().await;
 360                                                         // In theory we could check for if we've been instructed to disconnect
 361                                                         // the peer here, but its OK to just skip it - we'll check for it in
 362                                                         // schedule_read prior to any relevant calls into RL.
 363                                                 },
 364                                                 _ => {
 365                                                         eprintln!("Failed to write first full message to socket!");
 366                                                         peer_manager.as_ref().socket_disconnected(&SocketDescriptor::new(Arc::clone(&us)));
 367                                                         break Err(());
 368                                                 }
 369                                         }
 370                                 }
 371                         }).await {
 372                                 Connection::schedule_read(peer_manager, us, reader, read_receiver, write_receiver).await;
 373                         }
 374                 }))
 375         } else {
 376                 // Note that we will skip socket_disconnected here, in accordance with the PeerManager
 377                 // requirements.
 378                 None
 379         };
 380
 381         async move {
 382                 if let Some(handle) = handle_opt {
 383                         if let Err(e) = handle.await {
 384                                 assert!(e.is_cancelled());
 385                         } else {
 386                                 // This is certainly not guaranteed to always be true - the read loop may exit
 387                                 // while there are still pending write wakers that need to be woken up after the
 388                                 // socket shutdown(). Still, as a check during testing, to make sure tokio doesn't
 389                                 // keep too many wakers around, this makes sense. The race should be rare (we do
 390                                 // some work after shutdown()) and an error would be a major memory leak.
 391                                 #[cfg(test)]
 392                                 debug_assert!(Arc::try_unwrap(last_us).is_ok());
 393                         }
 394                 }
 395         }
 396 }
 397
 398 /// Process incoming messages and feed outgoing messages on a new connection made to the given
 399 /// socket address which is expected to be accepted by a peer with the given public key (by
 400 /// scheduling futures with tokio::spawn).
 401 ///
 402 /// Shorthand for TcpStream::connect(addr) with a timeout followed by setup_outbound().
 403 ///
 404 /// Returns a future (as the fn is async) which needs to be polled to complete the connection and
 405 /// connection setup. That future then returns a future which will complete when the peer is
 406 /// disconnected and associated handling futures are freed, though, because all processing in said
 407 /// futures are spawned with tokio::spawn, you do not need to poll the second future in order to
 408 /// make progress.
 409 pub async fn connect_outbound<PM: Deref + 'static + Send + Sync + Clone>(
 410         peer_manager: PM,
 411         their_node_id: PublicKey,
 412         addr: SocketAddr,
 413 ) -> Option<impl std::future::Future<Output=()>>
 414 where PM::Target: APeerManager<Descriptor = SocketDescriptor> {
 415         if let Ok(Ok(stream)) = time::timeout(Duration::from_secs(10), async { TcpStream::connect(&addr).await.map(|s| s.into_std().unwrap()) }).await {
 416                 Some(setup_outbound(peer_manager, their_node_id, stream))
 417         } else { None }
 418 }
 419
 420 const SOCK_WAKER_VTABLE: task::RawWakerVTable =
 421         task::RawWakerVTable::new(clone_socket_waker, wake_socket_waker, wake_socket_waker_by_ref, drop_socket_waker);
 422
 423 fn clone_socket_waker(orig_ptr: *const ()) -> task::RawWaker {
 424         let new_waker = unsafe { Arc::from_raw(orig_ptr as *const mpsc::Sender<()>) };
 425         let res = write_avail_to_waker(&new_waker);
 426         // Don't decrement the refcount when dropping new_waker by turning it back `into_raw`.
 427         let _ = Arc::into_raw(new_waker);
 428         res
 429 }
 430 // When waking, an error should be fine. Most likely we got two send_datas in a row, both of which
 431 // failed to fully write, but we only need to call write_buffer_space_avail() once. Otherwise, the
 432 // sending thread may have already gone away due to a socket close, in which case there's nothing
 433 // to wake up anyway.
 434 fn wake_socket_waker(orig_ptr: *const ()) {
 435         let sender = unsafe { &mut *(orig_ptr as *mut mpsc::Sender<()>) };
 436         let _ = sender.try_send(());
 437         drop_socket_waker(orig_ptr);
 438 }
 439 fn wake_socket_waker_by_ref(orig_ptr: *const ()) {
 440         let sender_ptr = orig_ptr as *const mpsc::Sender<()>;
 441         let sender = unsafe { &*sender_ptr };
 442         let _ = sender.try_send(());
 443 }
 444 fn drop_socket_waker(orig_ptr: *const ()) {
 445         let _orig_arc = unsafe { Arc::from_raw(orig_ptr as *mut mpsc::Sender<()>) };
 446         // _orig_arc is now dropped
 447 }
 448 fn write_avail_to_waker(sender: &Arc<mpsc::Sender<()>>) -> task::RawWaker {
 449         let new_ptr = Arc::into_raw(Arc::clone(&sender));
 450         task::RawWaker::new(new_ptr as *const (), &SOCK_WAKER_VTABLE)
 451 }
 452
 453 /// The SocketDescriptor used to refer to sockets by a PeerHandler. This is pub only as it is a
 454 /// type in the template of PeerHandler.
 455 pub struct SocketDescriptor {
 456         conn: Arc<Mutex<Connection>>,
 457         // We store a copy of the mpsc::Sender to wake the read task in an Arc here. While we can
 458         // simply clone the sender and store a copy in each waker, that would require allocating for
 459         // each waker. Instead, we can simply `Arc::clone`, creating a new reference and store the
 460         // pointer in the waker.
 461         write_avail_sender: Arc<mpsc::Sender<()>>,
 462         id: u64,
 463 }
 464 impl SocketDescriptor {
 465         fn new(conn: Arc<Mutex<Connection>>) -> Self {
 466                 let (id, write_avail_sender) = {
 467                         let us = conn.lock().unwrap();
 468                         (us.id, Arc::new(us.write_avail.clone()))
 469                 };
 470                 Self { conn, id, write_avail_sender }
 471         }
 472 }
 473 impl peer_handler::SocketDescriptor for SocketDescriptor {
 474         fn send_data(&mut self, data: &[u8], resume_read: bool) -> usize {
 475                 // To send data, we take a lock on our Connection to access the TcpStream, writing to it if
 476                 // there's room in the kernel buffer, or otherwise create a new Waker with a
 477                 // SocketDescriptor in it which can wake up the write_avail Sender, waking up the
 478                 // processing future which will call write_buffer_space_avail and we'll end up back here.
 479                 let mut us = self.conn.lock().unwrap();
 480                 if us.writer.is_none() {
 481                         // The writer gets take()n when it is time to shut down, so just fast-return 0 here.
 482                         return 0;
 483                 }
 484
 485                 if resume_read && us.read_paused {
 486                         // The schedule_read future may go to lock up but end up getting woken up by there
 487                         // being more room in the write buffer, dropping the other end of this Sender
 488                         // before we get here, so we ignore any failures to wake it up.
 489                         us.read_paused = false;
 490                         let _ = us.read_waker.try_send(());
 491                 }
 492                 if data.is_empty() { return 0; }
 493                 let waker = unsafe { task::Waker::from_raw(write_avail_to_waker(&self.write_avail_sender)) };
 494                 let mut ctx = task::Context::from_waker(&waker);
 495                 let mut written_len = 0;
 496                 loop {
 497                         match us.writer.as_ref().unwrap().poll_write_ready(&mut ctx) {
 498                                 task::Poll::Ready(Ok(())) => {
 499                                         match us.writer.as_ref().unwrap().try_write(&data[written_len..]) {
 500                                                 Ok(res) => {
 501                                                         debug_assert_ne!(res, 0);
 502                                                         written_len += res;
 503                                                         if written_len == data.len() { return written_len; }
 504                                                 },
 505                                                 Err(_) => return written_len,
 506                                         }
 507                                 },
 508                                 task::Poll::Ready(Err(_)) => return written_len,
 509                                 task::Poll::Pending => {
 510                                         // We're queued up for a write event now, but we need to make sure we also
 511                                         // pause read given we're now waiting on the remote end to ACK (and in
 512                                         // accordance with the send_data() docs).
 513                                         us.read_paused = true;
 514                                         // Further, to avoid any current pending read causing a `read_event` call, wake
 515                                         // up the read_waker and restart its loop.
 516                                         let _ = us.read_waker.try_send(());
 517                                         return written_len;
 518                                 },
 519                         }
 520                 }
 521         }
 522
 523         fn disconnect_socket(&mut self) {
 524                 let mut us = self.conn.lock().unwrap();
 525                 us.rl_requested_disconnect = true;
 526                 // Wake up the sending thread, assuming it is still alive
 527                 let _ = us.write_avail.try_send(());
 528         }
 529 }
 530 impl Clone for SocketDescriptor {
 531         fn clone(&self) -> Self {
 532                 Self {
 533                         conn: Arc::clone(&self.conn),
 534                         id: self.id,
 535                         write_avail_sender: Arc::clone(&self.write_avail_sender),
 536                 }
 537         }
 538 }
 539 impl Eq for SocketDescriptor {}
 540 impl PartialEq for SocketDescriptor {
 541         fn eq(&self, o: &Self) -> bool {
 542                 self.id == o.id
 543         }
 544 }
 545 impl Hash for SocketDescriptor {
 546         fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
 547                 self.id.hash(state);
 548         }
 549 }
 550
 551 #[cfg(test)]
 552 mod tests {
 553         use lightning::ln::features::*;
 554         use lightning::ln::msgs::*;
 555         use lightning::ln::peer_handler::{MessageHandler, PeerManager};
 556         use lightning::ln::features::NodeFeatures;
 557         use lightning::routing::gossip::NodeId;
 558         use lightning::events::*;
 559         use lightning::util::test_utils::TestNodeSigner;
 560         use bitcoin::Network;
 561         use bitcoin::blockdata::constants::ChainHash;
 562         use bitcoin::secp256k1::{Secp256k1, SecretKey, PublicKey};
 563
 564         use tokio::sync::mpsc;
 565
 566         use std::mem;
 567         use std::sync::atomic::{AtomicBool, Ordering};
 568         use std::sync::{Arc, Mutex};
 569         use std::time::Duration;
 570
 571         pub struct TestLogger();
 572         impl lightning::util::logger::Logger for TestLogger {
 573                 fn log(&self, record: lightning::util::logger::Record) {
 574                         println!("{:<5} [{} : {}, {}] {}", record.level.to_string(), record.module_path, record.file, record.line, record.args);
 575                 }
 576         }
 577
 578         struct MsgHandler{
 579                 expected_pubkey: PublicKey,
 580                 pubkey_connected: mpsc::Sender<()>,
 581                 pubkey_disconnected: mpsc::Sender<()>,
 582                 disconnected_flag: AtomicBool,
 583                 msg_events: Mutex<Vec<MessageSendEvent>>,
 584         }
 585         impl RoutingMessageHandler for MsgHandler {
 586                 fn handle_node_announcement(&self, _msg: &NodeAnnouncement) -> Result<bool, LightningError> { Ok(false) }
 587                 fn handle_channel_announcement(&self, _msg: &ChannelAnnouncement) -> Result<bool, LightningError> { Ok(false) }
 588                 fn handle_channel_update(&self, _msg: &ChannelUpdate) -> Result<bool, LightningError> { Ok(false) }
 589                 fn get_next_channel_announcement(&self, _starting_point: u64) -> Option<(ChannelAnnouncement, Option<ChannelUpdate>, Option<ChannelUpdate>)> { None }
 590                 fn get_next_node_announcement(&self, _starting_point: Option<&NodeId>) -> Option<NodeAnnouncement> { None }
 591                 fn peer_connected(&self, _their_node_id: &PublicKey, _init_msg: &Init, _inbound: bool) -> Result<(), ()> { Ok(()) }
 592                 fn handle_reply_channel_range(&self, _their_node_id: &PublicKey, _msg: ReplyChannelRange) -> Result<(), LightningError> { Ok(()) }
 593                 fn handle_reply_short_channel_ids_end(&self, _their_node_id: &PublicKey, _msg: ReplyShortChannelIdsEnd) -> Result<(), LightningError> { Ok(()) }
 594                 fn handle_query_channel_range(&self, _their_node_id: &PublicKey, _msg: QueryChannelRange) -> Result<(), LightningError> { Ok(()) }
 595                 fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: QueryShortChannelIds) -> Result<(), LightningError> { Ok(()) }
 596                 fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
 597                 fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures { InitFeatures::empty() }
 598                 fn processing_queue_high(&self) -> bool { false }
 599         }
 600         impl ChannelMessageHandler for MsgHandler {
 601                 fn handle_open_channel(&self, _their_node_id: &PublicKey, _msg: &OpenChannel) {}
 602                 fn handle_accept_channel(&self, _their_node_id: &PublicKey, _msg: &AcceptChannel) {}
 603                 fn handle_funding_created(&self, _their_node_id: &PublicKey, _msg: &FundingCreated) {}
 604                 fn handle_funding_signed(&self, _their_node_id: &PublicKey, _msg: &FundingSigned) {}
 605                 fn handle_channel_ready(&self, _their_node_id: &PublicKey, _msg: &ChannelReady) {}
 606                 fn handle_shutdown(&self, _their_node_id: &PublicKey, _msg: &Shutdown) {}
 607                 fn handle_closing_signed(&self, _their_node_id: &PublicKey, _msg: &ClosingSigned) {}
 608                 fn handle_update_add_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateAddHTLC) {}
 609                 fn handle_update_fulfill_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFulfillHTLC) {}
 610                 fn handle_update_fail_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFailHTLC) {}
 611                 fn handle_update_fail_malformed_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFailMalformedHTLC) {}
 612                 fn handle_commitment_signed(&self, _their_node_id: &PublicKey, _msg: &CommitmentSigned) {}
 613                 fn handle_revoke_and_ack(&self, _their_node_id: &PublicKey, _msg: &RevokeAndACK) {}
 614                 fn handle_update_fee(&self, _their_node_id: &PublicKey, _msg: &UpdateFee) {}
 615                 fn handle_announcement_signatures(&self, _their_node_id: &PublicKey, _msg: &AnnouncementSignatures) {}
 616                 fn handle_channel_update(&self, _their_node_id: &PublicKey, _msg: &ChannelUpdate) {}
 617                 fn handle_open_channel_v2(&self, _their_node_id: &PublicKey, _msg: &OpenChannelV2) {}
 618                 fn handle_accept_channel_v2(&self, _their_node_id: &PublicKey, _msg: &AcceptChannelV2) {}
 619                 fn handle_stfu(&self, _their_node_id: &PublicKey, _msg: &Stfu) {}
 620                 fn handle_splice(&self, _their_node_id: &PublicKey, _msg: &Splice) {}
 621                 fn handle_splice_ack(&self, _their_node_id: &PublicKey, _msg: &SpliceAck) {}
 622                 fn handle_splice_locked(&self, _their_node_id: &PublicKey, _msg: &SpliceLocked) {}
 623                 fn handle_tx_add_input(&self, _their_node_id: &PublicKey, _msg: &TxAddInput) {}
 624                 fn handle_tx_add_output(&self, _their_node_id: &PublicKey, _msg: &TxAddOutput) {}
 625                 fn handle_tx_remove_input(&self, _their_node_id: &PublicKey, _msg: &TxRemoveInput) {}
 626                 fn handle_tx_remove_output(&self, _their_node_id: &PublicKey, _msg: &TxRemoveOutput) {}
 627                 fn handle_tx_complete(&self, _their_node_id: &PublicKey, _msg: &TxComplete) {}
 628                 fn handle_tx_signatures(&self, _their_node_id: &PublicKey, _msg: &TxSignatures) {}
 629                 fn handle_tx_init_rbf(&self, _their_node_id: &PublicKey, _msg: &TxInitRbf) {}
 630                 fn handle_tx_ack_rbf(&self, _their_node_id: &PublicKey, _msg: &TxAckRbf) {}
 631                 fn handle_tx_abort(&self, _their_node_id: &PublicKey, _msg: &TxAbort) {}
 632                 fn peer_disconnected(&self, their_node_id: &PublicKey) {
 633                         if *their_node_id == self.expected_pubkey {
 634                                 self.disconnected_flag.store(true, Ordering::SeqCst);
 635                                 self.pubkey_disconnected.clone().try_send(()).unwrap();
 636                         }
 637                 }
 638                 fn peer_connected(&self, their_node_id: &PublicKey, _init_msg: &Init, _inbound: bool) -> Result<(), ()> {
 639                         if *their_node_id == self.expected_pubkey {
 640                                 self.pubkey_connected.clone().try_send(()).unwrap();
 641                         }
 642                         Ok(())
 643                 }
 644                 fn handle_channel_reestablish(&self, _their_node_id: &PublicKey, _msg: &ChannelReestablish) {}
 645                 fn handle_error(&self, _their_node_id: &PublicKey, _msg: &ErrorMessage) {}
 646                 fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
 647                 fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures { InitFeatures::empty() }
 648                 fn get_chain_hashes(&self) -> Option<Vec<ChainHash>> {
 649                         Some(vec![ChainHash::using_genesis_block(Network::Testnet)])
 650                 }
 651         }
 652         impl MessageSendEventsProvider for MsgHandler {
 653                 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {
 654                         let mut ret = Vec::new();
 655                         mem::swap(&mut *self.msg_events.lock().unwrap(), &mut ret);
 656                         ret
 657                 }
 658         }
 659
 660         fn make_tcp_connection() -> (std::net::TcpStream, std::net::TcpStream) {
 661                 if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9735") {
 662                         (std::net::TcpStream::connect("127.0.0.1:9735").unwrap(), listener.accept().unwrap().0)
 663                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:19735") {
 664                         (std::net::TcpStream::connect("127.0.0.1:19735").unwrap(), listener.accept().unwrap().0)
 665                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9997") {
 666                         (std::net::TcpStream::connect("127.0.0.1:9997").unwrap(), listener.accept().unwrap().0)
 667                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9998") {
 668                         (std::net::TcpStream::connect("127.0.0.1:9998").unwrap(), listener.accept().unwrap().0)
 669                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9999") {
 670                         (std::net::TcpStream::connect("127.0.0.1:9999").unwrap(), listener.accept().unwrap().0)
 671                 } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:46926") {
 672                         (std::net::TcpStream::connect("127.0.0.1:46926").unwrap(), listener.accept().unwrap().0)
 673                 } else { panic!("Failed to bind to v4 localhost on common ports"); }
 674         }
 675
 676         async fn do_basic_connection_test() {
 677                 let secp_ctx = Secp256k1::new();
 678                 let a_key = SecretKey::from_slice(&[1; 32]).unwrap();
 679                 let b_key = SecretKey::from_slice(&[1; 32]).unwrap();
 680                 let a_pub = PublicKey::from_secret_key(&secp_ctx, &a_key);
 681                 let b_pub = PublicKey::from_secret_key(&secp_ctx, &b_key);
 682
 683                 let (a_connected_sender, mut a_connected) = mpsc::channel(1);
 684                 let (a_disconnected_sender, mut a_disconnected) = mpsc::channel(1);
 685                 let a_handler = Arc::new(MsgHandler {
 686                         expected_pubkey: b_pub,
 687                         pubkey_connected: a_connected_sender,
 688                         pubkey_disconnected: a_disconnected_sender,
 689                         disconnected_flag: AtomicBool::new(false),
 690                         msg_events: Mutex::new(Vec::new()),
 691                 });
 692                 let a_manager = Arc::new(PeerManager::new(MessageHandler {
 693                         chan_handler: Arc::clone(&a_handler),
 694                         route_handler: Arc::clone(&a_handler),
 695                         onion_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
 696                         custom_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
 697                 }, 0, &[1; 32], Arc::new(TestLogger()), Arc::new(TestNodeSigner::new(a_key))));
 698
 699                 let (b_connected_sender, mut b_connected) = mpsc::channel(1);
 700                 let (b_disconnected_sender, mut b_disconnected) = mpsc::channel(1);
 701                 let b_handler = Arc::new(MsgHandler {
 702                         expected_pubkey: a_pub,
 703                         pubkey_connected: b_connected_sender,
 704                         pubkey_disconnected: b_disconnected_sender,
 705                         disconnected_flag: AtomicBool::new(false),
 706                         msg_events: Mutex::new(Vec::new()),
 707                 });
 708                 let b_manager = Arc::new(PeerManager::new(MessageHandler {
 709                         chan_handler: Arc::clone(&b_handler),
 710                         route_handler: Arc::clone(&b_handler),
 711                         onion_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
 712                         custom_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
 713                 }, 0, &[2; 32], Arc::new(TestLogger()), Arc::new(TestNodeSigner::new(b_key))));
 714
 715                 // We bind on localhost, hoping the environment is properly configured with a local
 716                 // address. This may not always be the case in containers and the like, so if this test is
 717                 // failing for you check that you have a loopback interface and it is configured with
 718                 // 127.0.0.1.
 719                 let (conn_a, conn_b) = make_tcp_connection();
 720
 721                 let fut_a = super::setup_outbound(Arc::clone(&a_manager), b_pub, conn_a);
 722                 let fut_b = super::setup_inbound(b_manager, conn_b);
 723
 724                 tokio::time::timeout(Duration::from_secs(10), a_connected.recv()).await.unwrap();
 725                 tokio::time::timeout(Duration::from_secs(1), b_connected.recv()).await.unwrap();
 726
 727                 a_handler.msg_events.lock().unwrap().push(MessageSendEvent::HandleError {
 728                         node_id: b_pub, action: ErrorAction::DisconnectPeer { msg: None }
 729                 });
 730                 assert!(!a_handler.disconnected_flag.load(Ordering::SeqCst));
 731                 assert!(!b_handler.disconnected_flag.load(Ordering::SeqCst));
 732
 733                 a_manager.process_events();
 734                 tokio::time::timeout(Duration::from_secs(10), a_disconnected.recv()).await.unwrap();
 735                 tokio::time::timeout(Duration::from_secs(1), b_disconnected.recv()).await.unwrap();
 736                 assert!(a_handler.disconnected_flag.load(Ordering::SeqCst));
 737                 assert!(b_handler.disconnected_flag.load(Ordering::SeqCst));
 738
 739                 fut_a.await;
 740                 fut_b.await;
 741         }
 742
 743         #[tokio::test(flavor = "multi_thread")]
 744         async fn basic_threaded_connection_test() {
 745                 do_basic_connection_test().await;
 746         }
 747
 748         #[tokio::test]
 749         async fn basic_unthreaded_connection_test() {
 750                 do_basic_connection_test().await;
 751         }
 752
 753         async fn race_disconnect_accept() {
 754                 // Previously, if we handed an already-disconnected socket to `setup_inbound` we'd panic.
 755                 // This attempts to find other similar races by opening connections and shutting them down
 756                 // while connecting. Sadly in testing this did *not* reproduce the previous issue.
 757                 let secp_ctx = Secp256k1::new();
 758                 let a_key = SecretKey::from_slice(&[1; 32]).unwrap();
 759                 let b_key = SecretKey::from_slice(&[2; 32]).unwrap();
 760                 let b_pub = PublicKey::from_secret_key(&secp_ctx, &b_key);
 761
 762                 let a_manager = Arc::new(PeerManager::new(MessageHandler {
 763                         chan_handler: Arc::new(lightning::ln::peer_handler::ErroringMessageHandler::new()),
 764                         onion_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
 765                         route_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
 766                         custom_message_handler: Arc::new(lightning::ln::peer_handler::IgnoringMessageHandler{}),
 767                 }, 0, &[1; 32], Arc::new(TestLogger()), Arc::new(TestNodeSigner::new(a_key))));
 768
 769                 // Make two connections, one for an inbound and one for an outbound connection
 770                 let conn_a = {
 771                         let (conn_a, _) = make_tcp_connection();
 772                         conn_a
 773                 };
 774                 let conn_b = {
 775                         let (_, conn_b) = make_tcp_connection();
 776                         conn_b
 777                 };
 778
 779                 // Call connection setup inside new tokio tasks.
 780                 let manager_reference = Arc::clone(&a_manager);
 781                 tokio::spawn(async move {
 782                         super::setup_inbound(manager_reference, conn_a).await
 783                 });
 784                 tokio::spawn(async move {
 785                         super::setup_outbound(a_manager, b_pub, conn_b).await
 786                 });
 787         }
 788
 789         #[tokio::test(flavor = "multi_thread")]
 790         async fn threaded_race_disconnect_accept() {
 791                 race_disconnect_accept().await;
 792         }
 793
 794         #[tokio::test]
 795         async fn unthreaded_race_disconnect_accept() {
 796                 race_disconnect_accept().await;
 797         }
 798 }