From: Matt Corallo Date: Sat, 1 Feb 2020 17:27:30 +0000 (-0500) Subject: Rewrite lightning-net-tokio using async/await and tokio 0.2 X-Git-Tag: v0.0.12~106^2~3 X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=5ada94046456909c07b135dca9ceac41963afdf4;p=rust-lightning Rewrite lightning-net-tokio using async/await and tokio 0.2 This is a rather major rewrite, using async/await and tokio 0.2, which cleans up the code a ton as well as adds significantly to readability. --- diff --git a/lightning-net-tokio/Cargo.toml b/lightning-net-tokio/Cargo.toml index 1bd9805a7..c915220d6 100644 --- a/lightning-net-tokio/Cargo.toml +++ b/lightning-net-tokio/Cargo.toml @@ -1,8 +1,9 @@ [package] name = "lightning-net-tokio" -version = "0.0.2" +version = "0.0.3" authors = ["Matt Corallo"] license = "Apache-2.0" +edition = "2018" description = """ Implementation of the rust-lightning network stack using Tokio. For Rust-Lightning clients which wish to make direct connections to Lightning P2P nodes, this is a simple alternative to implementing the nerequired network stack, especially for those already using Tokio. @@ -13,7 +14,7 @@ bitcoin = "0.21" bitcoin_hashes = "0.7" lightning = { version = "0.0.10", path = "../lightning" } secp256k1 = "0.15" -tokio-codec = "0.1" -futures = "0.1" -tokio = "0.1" -bytes = "0.4" +tokio = { version = ">=0.2.12", features = [ "io-util", "macros", "rt-core", "sync", "tcp", "time" ] } + +[dev-dependencies] +tokio = { version = ">=0.2.12", features = [ "io-util", "macros", "rt-core", "rt-threaded", "sync", "tcp", "time" ] } diff --git a/lightning-net-tokio/src/lib.rs b/lightning-net-tokio/src/lib.rs index d4621e000..08aa12571 100644 --- a/lightning-net-tokio/src/lib.rs +++ b/lightning-net-tokio/src/lib.rs @@ -1,279 +1,584 @@ -extern crate bytes; -extern crate tokio; -extern crate tokio_codec; -extern crate futures; -extern crate lightning; -extern crate secp256k1; - -use bytes::BufMut; - -use futures::future; -use futures::future::Future; -use futures::{AsyncSink, Stream, Sink}; -use futures::sync::mpsc; +//! A socket handling library for those running in Tokio environments who wish to use +//! rust-lightning with native TcpStreams. +//! +//! Designed to be as simple as possible, the high-level usage is almost as simple as "hand over a +//! TcpStream and a reference to a PeerManager and the rest is handled", except for the +//! [Event](../lightning/util/events/enum.Event.html) handlng mechanism, see below. +//! +//! The PeerHandler, due to the fire-and-forget nature of this logic, must be an Arc, and must use +//! the SocketDescriptor provided here as the PeerHandler's SocketDescriptor. +//! +//! Three methods are exposed to register a new connection for handling in tokio::spawn calls, see +//! their individual docs for more. All three take a +//! [mpsc::Sender<()>](../tokio/sync/mpsc/struct.Sender.html) which is sent into every time +//! something occurs which may result in lightning [Events](../lightning/util/events/enum.Event.html). +//! The call site should, thus, look something like this: +//! ``` +//! use tokio::sync::mpsc; +//! use tokio::net::TcpStream; +//! use secp256k1::key::PublicKey; +//! use lightning::util::events::EventsProvider; +//! use std::net::SocketAddr; +//! use std::sync::Arc; +//! +//! // Define concrete types for our high-level objects: +//! type TxBroadcaster = dyn lightning::chain::chaininterface::BroadcasterInterface; +//! type FeeEstimator = dyn lightning::chain::chaininterface::FeeEstimator; +//! type ChannelMonitor = lightning::ln::channelmonitor::SimpleManyChannelMonitor, Arc>; +//! type ChannelManager = lightning::ln::channelmanager::SimpleArcChannelManager; +//! type PeerManager = lightning::ln::peer_handler::SimpleArcPeerManager; +//! +//! // Connect to node with pubkey their_node_id at addr: +//! async fn connect_to_node(peer_manager: PeerManager, channel_monitor: Arc, channel_manager: ChannelManager, their_node_id: PublicKey, addr: SocketAddr) { +//! let (sender, mut receiver) = mpsc::channel(2); +//! lightning_net_tokio::connect_outbound(peer_manager, sender, their_node_id, addr).await; +//! loop { +//! receiver.recv().await; +//! for _event in channel_manager.get_and_clear_pending_events().drain(..) { +//! // Handle the event! +//! } +//! for _event in channel_monitor.get_and_clear_pending_events().drain(..) { +//! // Handle the event! +//! } +//! } +//! } +//! +//! // Begin reading from a newly accepted socket and talk to the peer: +//! async fn accept_socket(peer_manager: PeerManager, channel_monitor: Arc, channel_manager: ChannelManager, socket: TcpStream) { +//! let (sender, mut receiver) = mpsc::channel(2); +//! lightning_net_tokio::setup_inbound(peer_manager, sender, socket); +//! loop { +//! receiver.recv().await; +//! for _event in channel_manager.get_and_clear_pending_events().drain(..) { +//! // Handle the event! +//! } +//! for _event in channel_monitor.get_and_clear_pending_events().drain(..) { +//! // Handle the event! +//! } +//! } +//! } +//! ``` use secp256k1::key::PublicKey; -use tokio::timer::Delay; use tokio::net::TcpStream; +use tokio::{io, time}; +use tokio::sync::mpsc; +use tokio::io::{AsyncReadExt, AsyncWrite, AsyncWriteExt}; use lightning::ln::peer_handler; use lightning::ln::peer_handler::SocketDescriptor as LnSocketTrait; use lightning::ln::msgs::ChannelMessageHandler; -use std::mem; +use std::task; use std::net::SocketAddr; -use std::sync::{Arc, Mutex}; +use std::sync::{Arc, Mutex, MutexGuard}; use std::sync::atomic::{AtomicU64, Ordering}; -use std::time::{Duration, Instant}; -use std::vec::Vec; +use std::time::Duration; use std::hash::Hash; static ID_COUNTER: AtomicU64 = AtomicU64::new(0); -/// A connection to a remote peer. Can be constructed either as a remote connection using -/// Connection::setup_outbound o -pub struct Connection { - writer: Option>, +/// Connection contains all our internal state for a connection - we hold a reference to the +/// Connection object (in an Arc>) in each SocketDescriptor we create as well as in the +/// read future (which is returned by schedule_read). +struct Connection { + writer: Option>, event_notify: mpsc::Sender<()>, - pending_read: Vec, - read_blocker: Option>>, + // Because our PeerManager is templated by user-provided types, and we can't (as far as I can + // tell) have a const RawWakerVTable built out of templated functions, we need some indirection + // between being woken up with write-ready and calling PeerManager::write_buffer_spce_avail. + // This provides that indirection, with a Sender which gets handed to the PeerManager Arc on + // the schedule_read stack. + // + // An alternative (likely more effecient) approach would involve creating a RawWakerVTable at + // runtime with functions templated by the Arc type, calling + // write_buffer_space_avail directly from tokio's write wake, however doing so would require + // more unsafe voodo than I really feel like writing. + write_avail: mpsc::Sender<()>, + // When we are told by rust-lightning to pause read (because we have writes backing up), we do + // so by setting read_paused. At that point, the read task will stop reading bytes from the + // socket. To wake it up (without otherwise changing its state, we can push a value into this + // Sender. + read_waker: mpsc::Sender<()>, read_paused: bool, - need_disconnect: bool, + rl_requested_disconnect: bool, id: u64, } impl Connection { - fn schedule_read(peer_manager: Arc, Arc>>, us: Arc>, reader: futures::stream::SplitStream>) { - let us_ref = us.clone(); - let us_close_ref = us.clone(); + fn event_trigger(us: &mut MutexGuard) { + match us.event_notify.try_send(()) { + Ok(_) => {}, + Err(mpsc::error::TrySendError::Full(_)) => { + // Ignore full errors as we just need the user to poll after this point, so if they + // haven't received the last send yet, it doesn't matter. + }, + _ => panic!() + } + } + async fn schedule_read(peer_manager: Arc>>, us: Arc>, mut reader: io::ReadHalf, mut read_wake_receiver: mpsc::Receiver<()>, mut write_avail_receiver: mpsc::Receiver<()>) { let peer_manager_ref = peer_manager.clone(); - tokio::spawn(reader.for_each(move |b| { - let pending_read = b.to_vec(); - { - let mut lock = us_ref.lock().unwrap(); - assert!(lock.pending_read.is_empty()); - if lock.read_paused { - lock.pending_read = pending_read; - let (sender, blocker) = futures::sync::oneshot::channel(); - lock.read_blocker = Some(sender); - return future::Either::A(blocker.then(|_| { Ok(()) })); - } + // 8KB is nice and big but also should never cause any issues with stack overflowing. + let mut buf = [0; 8192]; + + let mut our_descriptor = SocketDescriptor::new(us.clone()); + // An enum describing why we did/are disconnecting: + enum Disconnect { + // Rust-Lightning told us to disconnect, either by returning an Err or by calling + // SocketDescriptor::disconnect_socket. + // In this case, we do not call peer_manager.socket_disconnected() as Rust-Lightning + // already knows we're disconnected. + CloseConnection, + // The connection was disconnected for some other reason, ie because the socket was + // closed. + // In this case, we do need to call peer_manager.socket_disconnected() to inform + // Rust-Lightning that the socket is gone. + PeerDisconnected + }; + let disconnect_type = loop { + macro_rules! shutdown_socket { + ($err: expr, $need_disconnect: expr) => { { + println!("Disconnecting peer due to {}!", $err); + break $need_disconnect; + } } } - //TODO: There's a race where we don't meet the requirements of socket_disconnected if its - //called right here, after we release the us_ref lock in the scope above, but before we - //call read_event! - match peer_manager.read_event(&mut SocketDescriptor::new(us_ref.clone(), peer_manager.clone()), &pending_read) { - Ok(pause_read) => { - if pause_read { - let mut lock = us_ref.lock().unwrap(); - lock.read_paused = true; + + let read_paused = us.lock().unwrap().read_paused; + tokio::select! { + v = write_avail_receiver.recv() => { + assert!(v.is_some()); // We can't have dropped the sending end, its in the us Arc! + if us.lock().unwrap().rl_requested_disconnect { + shutdown_socket!("disconnect_socket() call from RL", Disconnect::CloseConnection); + } + if let Err(e) = peer_manager.write_buffer_space_avail(&mut our_descriptor) { + shutdown_socket!(e, Disconnect::CloseConnection); } }, - Err(e) => { - us_ref.lock().unwrap().need_disconnect = false; - return future::Either::B(future::result(Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)))); - } + _ = read_wake_receiver.recv() => {}, + read = reader.read(&mut buf), if !read_paused => match read { + Ok(0) => shutdown_socket!("Connection closed", Disconnect::PeerDisconnected), + Ok(len) => { + if us.lock().unwrap().rl_requested_disconnect { + shutdown_socket!("disconnect_socket() call from RL", Disconnect::CloseConnection); + } + let read_res = peer_manager.read_event(&mut our_descriptor, &buf[0..len]); + match read_res { + Ok(pause_read) => { + let mut us_lock = us.lock().unwrap(); + if pause_read { + us_lock.read_paused = true; + } + Self::event_trigger(&mut us_lock); + }, + Err(e) => shutdown_socket!(e, Disconnect::CloseConnection), + } + }, + Err(e) => shutdown_socket!(e, Disconnect::PeerDisconnected), + }, } + }; + let writer_option = us.lock().unwrap().writer.take(); + if let Some(mut writer) = writer_option { + // If the socket is already closed, shutdown() will fail, so just ignore it. + let _ = writer.shutdown().await; + } + if let Disconnect::PeerDisconnected = disconnect_type { + peer_manager_ref.socket_disconnected(&our_descriptor); + Self::event_trigger(&mut us.lock().unwrap()); + } + } - if let Err(e) = us_ref.lock().unwrap().event_notify.try_send(()) { - // Ignore full errors as we just need them to poll after this point, so if the user - // hasn't received the last send yet, it doesn't matter. - assert!(e.is_full()); - } + fn new(event_notify: mpsc::Sender<()>, stream: TcpStream) -> (io::ReadHalf, mpsc::Receiver<()>, mpsc::Receiver<()>, Arc>) { + // We only ever need a channel of depth 1 here: if we returned a non-full write to the + // PeerManager, we will eventually get notified that there is room in the socket to write + // new bytes, which will generate an event. That event will be popped off the queue before + // we call write_buffer_space_avail, ensuring that we have room to push a new () if, during + // the write_buffer_space_avail() call, send_data() returns a non-full write. + let (write_avail, write_receiver) = mpsc::channel(1); + // Similarly here - our only goal is to make sure the reader wakes up at some point after + // we shove a value into the channel which comes after we've reset the read_paused bool to + // false. + let (read_waker, read_receiver) = mpsc::channel(1); + let (reader, writer) = io::split(stream); - future::Either::B(future::result(Ok(()))) - }).then(move |_| { - if us_close_ref.lock().unwrap().need_disconnect { - peer_manager_ref.socket_disconnected(&SocketDescriptor::new(us_close_ref, peer_manager_ref.clone())); - println!("Peer disconnected!"); - } else { - println!("We disconnected peer!"); - } - Ok(()) - })); + (reader, write_receiver, read_receiver, + Arc::new(Mutex::new(Self { + writer: Some(writer), event_notify, write_avail, read_waker, + read_paused: false, rl_requested_disconnect: false, + id: ID_COUNTER.fetch_add(1, Ordering::AcqRel) + }))) } +} - fn new(event_notify: mpsc::Sender<()>, stream: TcpStream) -> (futures::stream::SplitStream>, Arc>) { - let (writer, reader) = tokio_codec::Framed::new(stream, tokio_codec::BytesCodec::new()).split(); - let (send_sink, send_stream) = mpsc::channel(3); - tokio::spawn(writer.send_all(send_stream.map_err(|_| -> std::io::Error { - unreachable!(); - })).then(|_| { - future::result(Ok(())) - })); - let us = Arc::new(Mutex::new(Self { writer: Some(send_sink), event_notify, pending_read: Vec::new(), read_blocker: None, read_paused: false, need_disconnect: true, id: ID_COUNTER.fetch_add(1, Ordering::AcqRel) })); - - (reader, us) - } +/// Process incoming messages and feed outgoing messages on the provided socket generated by +/// accepting an incoming connection. +/// +/// The returned future will complete when the peer is disconnected and associated handling +/// futures are freed, though, because all processing futures are spawned with tokio::spawn, you do +/// not need to poll the provided future in order to make progress. +/// +/// See the module-level documentation for how to handle the event_notify mpsc::Sender. +pub fn setup_inbound(peer_manager: Arc>>, event_notify: mpsc::Sender<()>, stream: TcpStream) -> impl std::future::Future { + let (reader, write_receiver, read_receiver, us) = Connection::new(event_notify, stream); + #[cfg(debug_assertions)] + let last_us = Arc::clone(&us); - /// Process incoming messages and feed outgoing messages on the provided socket generated by - /// accepting an incoming connection (by scheduling futures with tokio::spawn). - /// - /// You should poll the Receive end of event_notify and call get_and_clear_pending_events() on - /// ChannelManager and ChannelMonitor objects. - pub fn setup_inbound(peer_manager: Arc, Arc>>, event_notify: mpsc::Sender<()>, stream: TcpStream) { - let (reader, us) = Self::new(event_notify, stream); + let handle_opt = if let Ok(_) = peer_manager.new_inbound_connection(SocketDescriptor::new(us.clone())) { + Some(tokio::spawn(Connection::schedule_read(peer_manager, us, reader, read_receiver, write_receiver))) + } else { + // Note that we will skip socket_disconnected here, in accordance with the PeerManager + // requirements. + None + }; - if let Ok(_) = peer_manager.new_inbound_connection(SocketDescriptor::new(us.clone(), peer_manager.clone())) { - Self::schedule_read(peer_manager, us, reader); + async move { + if let Some(handle) = handle_opt { + if let Err(e) = handle.await { + assert!(e.is_cancelled()); + } else { + // This is certainly not guaranteed to always be true - the read loop may exit + // while there are still pending write wakers that need to be woken up after the + // socket shutdown(). Still, as a check during testing, to make sure tokio doesn't + // keep too many wakers around, this makes sense. The race should be rare (we do + // some work after shutdown()) and an error would be a major memory leak. + #[cfg(debug_assertions)] + assert!(Arc::try_unwrap(last_us).is_ok()); + } } } +} + +/// Process incoming messages and feed outgoing messages on the provided socket generated by +/// making an outbound connection which is expected to be accepted by a peer with the given +/// public key. The relevant processing is set to run free (via tokio::spawn). +/// +/// The returned future will complete when the peer is disconnected and associated handling +/// futures are freed, though, because all processing futures are spawned with tokio::spawn, you do +/// not need to poll the provided future in order to make progress. +/// +/// See the module-level documentation for how to handle the event_notify mpsc::Sender. +pub fn setup_outbound(peer_manager: Arc>>, event_notify: mpsc::Sender<()>, their_node_id: PublicKey, stream: TcpStream) -> impl std::future::Future { + let (reader, write_receiver, read_receiver, us) = Connection::new(event_notify, stream); + #[cfg(debug_assertions)] + let last_us = Arc::clone(&us); + + let handle_opt = if let Ok(initial_send) = peer_manager.new_outbound_connection(their_node_id, SocketDescriptor::new(us.clone())) { + Some(tokio::spawn(async move { + if SocketDescriptor::new(us.clone()).send_data(&initial_send, true) != initial_send.len() { + // We should essentially always have enough room in a TCP socket buffer to send the + // initial 10s of bytes, if not, just give up as hopeless. + eprintln!("Failed to write first full message to socket!"); + peer_manager.socket_disconnected(&SocketDescriptor::new(Arc::clone(&us))); + } else { + Connection::schedule_read(peer_manager, us, reader, read_receiver, write_receiver).await; + } + })) + } else { + // Note that we will skip socket_disconnected here, in accordance with the PeerManager + // requirements. + None + }; - /// Process incoming messages and feed outgoing messages on the provided socket generated by - /// making an outbound connection which is expected to be accepted by a peer with the given - /// public key (by scheduling futures with tokio::spawn). - /// - /// You should poll the Receive end of event_notify and call get_and_clear_pending_events() on - /// ChannelManager and ChannelMonitor objects. - pub fn setup_outbound(peer_manager: Arc, Arc>>, event_notify: mpsc::Sender<()>, their_node_id: PublicKey, stream: TcpStream) { - let (reader, us) = Self::new(event_notify, stream); - - if let Ok(initial_send) = peer_manager.new_outbound_connection(their_node_id, SocketDescriptor::new(us.clone(), peer_manager.clone())) { - if SocketDescriptor::new(us.clone(), peer_manager.clone()).send_data(&initial_send, true) == initial_send.len() { - Self::schedule_read(peer_manager, us, reader); + async move { + if let Some(handle) = handle_opt { + if let Err(e) = handle.await { + assert!(e.is_cancelled()); } else { - println!("Failed to write first full message to socket!"); + // This is certainly not guaranteed to always be true - the read loop may exit + // while there are still pending write wakers that need to be woken up after the + // socket shutdown(). Still, as a check during testing, to make sure tokio doesn't + // keep too many wakers around, this makes sense. The race should be rare (we do + // some work after shutdown()) and an error would be a major memory leak. + #[cfg(debug_assertions)] + assert!(Arc::try_unwrap(last_us).is_ok()); } } } +} - /// Process incoming messages and feed outgoing messages on a new connection made to the given - /// socket address which is expected to be accepted by a peer with the given public key (by - /// scheduling futures with tokio::spawn). - /// - /// You should poll the Receive end of event_notify and call get_and_clear_pending_events() on - /// ChannelManager and ChannelMonitor objects. - pub fn connect_outbound(peer_manager: Arc, Arc>>, event_notify: mpsc::Sender<()>, their_node_id: PublicKey, addr: SocketAddr) { - let connect_timeout = Delay::new(Instant::now() + Duration::from_secs(10)).then(|_| { - future::err(std::io::Error::new(std::io::ErrorKind::TimedOut, "timeout reached")) - }); - tokio::spawn(TcpStream::connect(&addr).select(connect_timeout) - .and_then(move |stream| { - Connection::setup_outbound(peer_manager, event_notify, their_node_id, stream.0); - future::ok(()) - }).or_else(|_| { - //TODO: return errors somehow - future::ok(()) - })); - } +/// Process incoming messages and feed outgoing messages on a new connection made to the given +/// socket address which is expected to be accepted by a peer with the given public key (by +/// scheduling futures with tokio::spawn). +/// +/// Shorthand for TcpStream::connect(addr) with a timeout followed by setup_outbound(). +/// +/// Returns a future (as the fn is async) which needs to be polled to complete the connection and +/// connection setup. That future then returns a future which will complete when the peer is +/// disconnected and associated handling futures are freed, though, because all processing in said +/// futures are spawned with tokio::spawn, you do not need to poll the second future in order to +/// make progress. +/// +/// See the module-level documentation for how to handle the event_notify mpsc::Sender. +pub async fn connect_outbound(peer_manager: Arc>>, event_notify: mpsc::Sender<()>, their_node_id: PublicKey, addr: SocketAddr) -> Option> { + if let Ok(Ok(stream)) = time::timeout(Duration::from_secs(10), TcpStream::connect(&addr)).await { + Some(setup_outbound(peer_manager, event_notify, their_node_id, stream)) + } else { None } } -pub struct SocketDescriptor { +const SOCK_WAKER_VTABLE: task::RawWakerVTable = + task::RawWakerVTable::new(clone_socket_waker, wake_socket_waker, wake_socket_waker_by_ref, drop_socket_waker); + +fn clone_socket_waker(orig_ptr: *const ()) -> task::RawWaker { + write_avail_to_waker(orig_ptr as *const mpsc::Sender<()>) +} +// When waking, an error should be fine. Most likely we got two send_datas in a row, both of which +// failed to fully write, but we only need to call write_buffer_space_avail() once. Otherwise, the +// sending thread may have already gone away due to a socket close, in which case there's nothing +// to wake up anyway. +fn wake_socket_waker(orig_ptr: *const ()) { + let sender = unsafe { &mut *(orig_ptr as *mut mpsc::Sender<()>) }; + let _ = sender.try_send(()); + drop_socket_waker(orig_ptr); +} +fn wake_socket_waker_by_ref(orig_ptr: *const ()) { + let sender_ptr = orig_ptr as *const mpsc::Sender<()>; + let mut sender = unsafe { (*sender_ptr).clone() }; + let _ = sender.try_send(()); +} +fn drop_socket_waker(orig_ptr: *const ()) { + let _orig_box = unsafe { Box::from_raw(orig_ptr as *mut mpsc::Sender<()>) }; + // _orig_box is now dropped +} +fn write_avail_to_waker(sender: *const mpsc::Sender<()>) -> task::RawWaker { + let new_box = Box::leak(Box::new(unsafe { (*sender).clone() })); + let new_ptr = new_box as *const mpsc::Sender<()>; + task::RawWaker::new(new_ptr as *const (), &SOCK_WAKER_VTABLE) +} + +/// The SocketDescriptor used to refer to sockets by a PeerHandler. This is pub only as it is a +/// type in the template of PeerHandler. +pub struct SocketDescriptor { conn: Arc>, id: u64, - peer_manager: Arc, Arc>>, } -impl SocketDescriptor { - fn new(conn: Arc>, peer_manager: Arc, Arc>>) -> Self { +impl SocketDescriptor { + fn new(conn: Arc>) -> Self { let id = conn.lock().unwrap().id; - Self { conn, id, peer_manager } + Self { conn, id } } } -impl peer_handler::SocketDescriptor for SocketDescriptor { +impl peer_handler::SocketDescriptor for SocketDescriptor { fn send_data(&mut self, data: &[u8], resume_read: bool) -> usize { - macro_rules! schedule_read { - ($us_ref: expr) => { - tokio::spawn(future::lazy(move || -> Result<(), ()> { - let mut read_data = Vec::new(); - { - let mut us = $us_ref.conn.lock().unwrap(); - mem::swap(&mut read_data, &mut us.pending_read); - } - if !read_data.is_empty() { - let mut us_clone = $us_ref.clone(); - match $us_ref.peer_manager.read_event(&mut us_clone, &read_data) { - Ok(pause_read) => { - if pause_read { return Ok(()); } - }, - Err(_) => { - //TODO: Not actually sure how to do this - return Ok(()); - } - } - } - let mut us = $us_ref.conn.lock().unwrap(); - if let Some(sender) = us.read_blocker.take() { - sender.send(Ok(())).unwrap(); - } - us.read_paused = false; - if let Err(e) = us.event_notify.try_send(()) { - // Ignore full errors as we just need them to poll after this point, so if the user - // hasn't received the last send yet, it doesn't matter. - assert!(e.is_full()); - } - Ok(()) - })); - } - } - + // To send data, we take a lock on our Connection to access the WriteHalf of the TcpStream, + // writing to it if there's room in the kernel buffer, or otherwise create a new Waker with + // a SocketDescriptor in it which can wake up the write_avail Sender, waking up the + // processing future which will call write_buffer_space_avail and we'll end up back here. let mut us = self.conn.lock().unwrap(); - if resume_read { - let us_ref = self.clone(); - schedule_read!(us_ref); - } - if data.is_empty() { return 0; } if us.writer.is_none() { - us.read_paused = true; + // The writer gets take()n when it is time to shut down, so just fast-return 0 here. return 0; } - let mut bytes = bytes::BytesMut::with_capacity(data.len()); - bytes.put(data); - let write_res = us.writer.as_mut().unwrap().start_send(bytes.freeze()); - match write_res { - Ok(res) => { - match res { - AsyncSink::Ready => { - data.len() - }, - AsyncSink::NotReady(_) => { - us.read_paused = true; - let us_ref = self.clone(); - tokio::spawn(us.writer.take().unwrap().flush().then(move |writer_res| -> Result<(), ()> { - if let Ok(writer) = writer_res { - { - let mut us = us_ref.conn.lock().unwrap(); - us.writer = Some(writer); - } - schedule_read!(us_ref); - } // we'll fire the disconnect event on the socket reader end - Ok(()) - })); - 0 - } - } - }, - Err(_) => { - // We'll fire the disconnected event on the socket reader end - 0 - }, + if resume_read && us.read_paused { + // The schedule_read future may go to lock up but end up getting woken up by there + // being more room in the write buffer, dropping the other end of this Sender + // before we get here, so we ignore any failures to wake it up. + us.read_paused = false; + let _ = us.read_waker.try_send(()); + } + if data.is_empty() { return 0; } + let waker = unsafe { task::Waker::from_raw(write_avail_to_waker(&us.write_avail)) }; + let mut ctx = task::Context::from_waker(&waker); + let mut written_len = 0; + loop { + match std::pin::Pin::new(us.writer.as_mut().unwrap()).poll_write(&mut ctx, &data[written_len..]) { + task::Poll::Ready(Ok(res)) => { + // The tokio docs *seem* to indicate this can't happen, and I certainly don't + // know how to handle it if it does (cause it should be a Poll::Pending + // instead): + assert_ne!(res, 0); + written_len += res; + if written_len == data.len() { return written_len; } + }, + task::Poll::Ready(Err(e)) => { + // The tokio docs *seem* to indicate this can't happen, and I certainly don't + // know how to handle it if it does (cause it should be a Poll::Pending + // instead): + assert_ne!(e.kind(), io::ErrorKind::WouldBlock); + // Probably we've already been closed, just return what we have and let the + // read thread handle closing logic. + return written_len; + }, + task::Poll::Pending => { + // We're queued up for a write event now, but we need to make sure we also + // pause read given we're now waiting on the remote end to ACK (and in + // accordance with the send_data() docs). + us.read_paused = true; + return written_len; + }, + } } } fn disconnect_socket(&mut self) { let mut us = self.conn.lock().unwrap(); - us.need_disconnect = true; + us.rl_requested_disconnect = true; us.read_paused = true; + // Wake up the sending thread, assuming it is still alive + let _ = us.write_avail.try_send(()); + // TODO: There's a race where we don't meet the requirements of disconnect_socket if the + // read task is about to call a PeerManager function (eg read_event or write_event). + // Ideally we need to release the us lock and block until we have confirmation from the + // read task that it has broken out of its main loop. } } -impl Clone for SocketDescriptor { +impl Clone for SocketDescriptor { fn clone(&self) -> Self { Self { conn: Arc::clone(&self.conn), id: self.id, - peer_manager: Arc::clone(&self.peer_manager), } } } -impl Eq for SocketDescriptor {} -impl PartialEq for SocketDescriptor { +impl Eq for SocketDescriptor {} +impl PartialEq for SocketDescriptor { fn eq(&self, o: &Self) -> bool { self.id == o.id } } -impl Hash for SocketDescriptor { +impl Hash for SocketDescriptor { fn hash(&self, state: &mut H) { self.id.hash(state); } } +#[cfg(test)] +mod tests { + use lightning::ln::features::*; + use lightning::ln::msgs::*; + use lightning::ln::peer_handler::{MessageHandler, PeerManager}; + use lightning::util::events::*; + use secp256k1::{Secp256k1, SecretKey, PublicKey}; + + use tokio::sync::mpsc; + + use std::mem; + use std::sync::{Arc, Mutex}; + use std::time::Duration; + + pub struct TestLogger(); + impl lightning::util::logger::Logger for TestLogger { + fn log(&self, record: &lightning::util::logger::Record) { + println!("{:<5} [{} : {}, {}] {}", record.level.to_string(), record.module_path, record.file, record.line, record.args); + } + } + + struct MsgHandler{ + expected_pubkey: PublicKey, + pubkey_connected: mpsc::Sender<()>, + pubkey_disconnected: mpsc::Sender<()>, + msg_events: Mutex>, + } + impl RoutingMessageHandler for MsgHandler { + fn handle_node_announcement(&self, _msg: &NodeAnnouncement) -> Result { Ok(false) } + fn handle_channel_announcement(&self, _msg: &ChannelAnnouncement) -> Result { Ok(false) } + fn handle_channel_update(&self, _msg: &ChannelUpdate) -> Result { Ok(false) } + fn handle_htlc_fail_channel_update(&self, _update: &HTLCFailChannelUpdate) { } + fn get_next_channel_announcements(&self, _starting_point: u64, _batch_amount: u8) -> Vec<(ChannelAnnouncement, ChannelUpdate, ChannelUpdate)> { Vec::new() } + fn get_next_node_announcements(&self, _starting_point: Option<&PublicKey>, _batch_amount: u8) -> Vec { Vec::new() } + fn should_request_full_sync(&self, _node_id: &PublicKey) -> bool { false } + } + impl ChannelMessageHandler for MsgHandler { + fn handle_open_channel(&self, _their_node_id: &PublicKey, _their_features: InitFeatures, _msg: &OpenChannel) {} + fn handle_accept_channel(&self, _their_node_id: &PublicKey, _their_features: InitFeatures, _msg: &AcceptChannel) {} + fn handle_funding_created(&self, _their_node_id: &PublicKey, _msg: &FundingCreated) {} + fn handle_funding_signed(&self, _their_node_id: &PublicKey, _msg: &FundingSigned) {} + fn handle_funding_locked(&self, _their_node_id: &PublicKey, _msg: &FundingLocked) {} + fn handle_shutdown(&self, _their_node_id: &PublicKey, _msg: &Shutdown) {} + fn handle_closing_signed(&self, _their_node_id: &PublicKey, _msg: &ClosingSigned) {} + fn handle_update_add_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateAddHTLC) {} + fn handle_update_fulfill_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFulfillHTLC) {} + fn handle_update_fail_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFailHTLC) {} + fn handle_update_fail_malformed_htlc(&self, _their_node_id: &PublicKey, _msg: &UpdateFailMalformedHTLC) {} + fn handle_commitment_signed(&self, _their_node_id: &PublicKey, _msg: &CommitmentSigned) {} + fn handle_revoke_and_ack(&self, _their_node_id: &PublicKey, _msg: &RevokeAndACK) {} + fn handle_update_fee(&self, _their_node_id: &PublicKey, _msg: &UpdateFee) {} + fn handle_announcement_signatures(&self, _their_node_id: &PublicKey, _msg: &AnnouncementSignatures) {} + fn peer_disconnected(&self, their_node_id: &PublicKey, _no_connection_possible: bool) { + if *their_node_id == self.expected_pubkey { + self.pubkey_disconnected.clone().try_send(()).unwrap(); + } + } + fn peer_connected(&self, their_node_id: &PublicKey, _msg: &Init) { + if *their_node_id == self.expected_pubkey { + self.pubkey_connected.clone().try_send(()).unwrap(); + } + } + fn handle_channel_reestablish(&self, _their_node_id: &PublicKey, _msg: &ChannelReestablish) {} + fn handle_error(&self, _their_node_id: &PublicKey, _msg: &ErrorMessage) {} + } + impl MessageSendEventsProvider for MsgHandler { + fn get_and_clear_pending_msg_events(&self) -> Vec { + let mut ret = Vec::new(); + mem::swap(&mut *self.msg_events.lock().unwrap(), &mut ret); + ret + } + } + + #[tokio::test(threaded_scheduler)] + async fn basic_connection_test() { + let secp_ctx = Secp256k1::new(); + let a_key = SecretKey::from_slice(&[1; 32]).unwrap(); + let b_key = SecretKey::from_slice(&[1; 32]).unwrap(); + let a_pub = PublicKey::from_secret_key(&secp_ctx, &a_key); + let b_pub = PublicKey::from_secret_key(&secp_ctx, &b_key); + + let (a_connected_sender, mut a_connected) = mpsc::channel(1); + let (a_disconnected_sender, mut a_disconnected) = mpsc::channel(1); + let a_handler = Arc::new(MsgHandler { + expected_pubkey: b_pub, + pubkey_connected: a_connected_sender, + pubkey_disconnected: a_disconnected_sender, + msg_events: Mutex::new(Vec::new()), + }); + let a_manager = Arc::new(PeerManager::new(MessageHandler { + chan_handler: Arc::clone(&a_handler), + route_handler: Arc::clone(&a_handler) as Arc, + }, a_key.clone(), &[1; 32], Arc::new(TestLogger()))); + + let (b_connected_sender, mut b_connected) = mpsc::channel(1); + let (b_disconnected_sender, mut b_disconnected) = mpsc::channel(1); + let b_handler = Arc::new(MsgHandler { + expected_pubkey: a_pub, + pubkey_connected: b_connected_sender, + pubkey_disconnected: b_disconnected_sender, + msg_events: Mutex::new(Vec::new()), + }); + let b_manager = Arc::new(PeerManager::new(MessageHandler { + chan_handler: Arc::clone(&b_handler), + route_handler: Arc::clone(&b_handler) as Arc, + }, b_key.clone(), &[2; 32], Arc::new(TestLogger()))); + + // We bind on localhost, hoping the environment is properly configured with a local + // address. This may not always be the case in containers and the like, so if this test is + // failing for you check that you have a loopback interface and it is configured with + // 127.0.0.1. + let (conn_a, conn_b) = if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9735") { + (std::net::TcpStream::connect("127.0.0.1:9735").unwrap(), listener.accept().unwrap().0) + } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:9999") { + (std::net::TcpStream::connect("127.0.0.1:9999").unwrap(), listener.accept().unwrap().0) + } else if let Ok(listener) = std::net::TcpListener::bind("127.0.0.1:46926") { + (std::net::TcpStream::connect("127.0.0.1:46926").unwrap(), listener.accept().unwrap().0) + } else { panic!("Failed to bind to v4 localhost on common ports"); }; + + let (sender, _receiver) = mpsc::channel(2); + let fut_a = super::setup_outbound(Arc::clone(&a_manager), sender.clone(), b_pub, tokio::net::TcpStream::from_std(conn_a).unwrap()); + let fut_b = super::setup_inbound(b_manager, sender, tokio::net::TcpStream::from_std(conn_b).unwrap()); + + tokio::time::timeout(Duration::from_secs(10), a_connected.recv()).await.unwrap(); + tokio::time::timeout(Duration::from_secs(1), b_connected.recv()).await.unwrap(); + + a_handler.msg_events.lock().unwrap().push(MessageSendEvent::HandleError { + node_id: b_pub, action: ErrorAction::DisconnectPeer { msg: None } + }); + assert!(a_disconnected.try_recv().is_err()); + assert!(b_disconnected.try_recv().is_err()); + + a_manager.process_events(); + tokio::time::timeout(Duration::from_secs(10), a_disconnected.recv()).await.unwrap(); + tokio::time::timeout(Duration::from_secs(1), b_disconnected.recv()).await.unwrap(); + + fut_a.await; + fut_b.await; + } +}