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Merge pull request #472 from TheBlueMatt/2020-01-net-async-await

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Rewrite lightning-net-tokio using async/await and tokio 0.2
This commit is contained in:
Matt Corallo 2020-03-11 17:41:57 +00:00 • committed by GitHub
commit d27e9e1c6a
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4 changed files with 580 additions and 233 deletions
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2
fuzz/src/full_stack.rs
View file

@ -384,7 +384,7 @@ pub fn do_test(data: &[u8], logger: &Arc<dyn Logger>) {
3 => { 3 => {
let peer_id = get_slice!(1)[0]; let peer_id = get_slice!(1)[0];
if !peers.borrow()[peer_id as usize] { return; } if !peers.borrow()[peer_id as usize] { return; }
match loss_detector.handler.read_event(&mut Peer{id: peer_id, peers_connected: &peers}, get_slice!(get_slice!(1)[0]).to_vec()) { match loss_detector.handler.read_event(&mut Peer{id: peer_id, peers_connected: &peers}, get_slice!(get_slice!(1)[0])) {
Ok(res) => assert!(!res), Ok(res) => assert!(!res),
Err(_) => { peers.borrow_mut()[peer_id as usize] = false; } Err(_) => { peers.borrow_mut()[peer_id as usize] = false; }
} }

13
lightning-net-tokio/Cargo.toml
View file

@ -1,11 +1,12 @@
[package] [package]
name = "lightning-net-tokio" name = "lightning-net-tokio"
version = "0.0.2" version = "0.0.3"
authors = ["Matt Corallo"] authors = ["Matt Corallo"]
license = "Apache-2.0" license = "Apache-2.0"
edition = "2018"
description = """ description = """
Implementation of the rust-lightning network stack using Tokio. 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. For Rust-Lightning clients which wish to make direct connections to Lightning P2P nodes, this is a simple alternative to implementing the required network stack, especially for those already using Tokio.
""" """
[dependencies] [dependencies]
@ -13,7 +14,7 @@ bitcoin = "0.21"
bitcoin_hashes = "0.7" bitcoin_hashes = "0.7"
lightning = { version = "0.0.10", path = "../lightning" } lightning = { version = "0.0.10", path = "../lightning" }
secp256k1 = "0.15" secp256k1 = "0.15"
tokio-codec = "0.1" tokio = { version = ">=0.2.12", features = [ "io-util", "macros", "rt-core", "sync", "tcp", "time" ] }
futures = "0.1"
tokio = "0.1" [dev-dependencies]
bytes = "0.4" tokio = { version = ">=0.2.12", features = [ "io-util", "macros", "rt-core", "rt-threaded", "sync", "tcp", "time" ] }

788
lightning-net-tokio/src/lib.rs
View file

@ -1,279 +1,625 @@
extern crate bytes; //! A socket handling library for those running in Tokio environments who wish to use
extern crate tokio; //! rust-lightning with native TcpStreams.
extern crate tokio_codec; //!
extern crate futures; //! Designed to be as simple as possible, the high-level usage is almost as simple as "hand over a
extern crate lightning; //! TcpStream and a reference to a PeerManager and the rest is handled", except for the
extern crate secp256k1; //! [Event](../lightning/util/events/enum.Event.html) handlng mechanism, see below.
//!
use bytes::BufMut; //! 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.
use futures::future; //!
use futures::future::Future; //! Three methods are exposed to register a new connection for handling in tokio::spawn calls, see
use futures::{AsyncSink, Stream, Sink}; //! their individual docs for more. All three take a
use futures::sync::mpsc; //! [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<lightning::chain::transaction::OutPoint, lightning::chain::keysinterface::InMemoryChannelKeys, Arc<TxBroadcaster>, Arc<FeeEstimator>>;
//! type ChannelManager = lightning::ln::channelmanager::SimpleArcChannelManager<ChannelMonitor, TxBroadcaster, FeeEstimator>;
//! type PeerManager = lightning::ln::peer_handler::SimpleArcPeerManager<lightning_net_tokio::SocketDescriptor, ChannelMonitor, TxBroadcaster, FeeEstimator>;
//!
//! // Connect to node with pubkey their_node_id at addr:
//! async fn connect_to_node(peer_manager: PeerManager, channel_monitor: Arc<ChannelMonitor>, 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<ChannelMonitor>, 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 secp256k1::key::PublicKey;
use tokio::timer::Delay;
use tokio::net::TcpStream; 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;
use lightning::ln::peer_handler::SocketDescriptor as LnSocketTrait; use lightning::ln::peer_handler::SocketDescriptor as LnSocketTrait;
use lightning::ln::msgs::ChannelMessageHandler; use lightning::ln::msgs::ChannelMessageHandler;
use std::mem; use std::{task, thread};
use std::net::SocketAddr; use std::net::SocketAddr;
use std::sync::{Arc, Mutex}; use std::sync::{Arc, Mutex, MutexGuard};
use std::sync::atomic::{AtomicU64, Ordering}; use std::sync::atomic::{AtomicU64, Ordering};
use std::time::{Duration, Instant}; use std::time::Duration;
use std::vec::Vec;
use std::hash::Hash; use std::hash::Hash;
static ID_COUNTER: AtomicU64 = AtomicU64::new(0); static ID_COUNTER: AtomicU64 = AtomicU64::new(0);
/// A connection to a remote peer. Can be constructed either as a remote connection using /// Connection contains all our internal state for a connection - we hold a reference to the
/// Connection::setup_outbound o /// Connection object (in an Arc<Mutex<>>) in each SocketDescriptor we create as well as in the
pub struct Connection { /// read future (which is returned by schedule_read).
writer: Option<mpsc::Sender<bytes::Bytes>>, struct Connection {
writer: Option<io::WriteHalf<TcpStream>>,
event_notify: mpsc::Sender<()>, event_notify: mpsc::Sender<()>,
pending_read: Vec<u8>, // Because our PeerManager is templated by user-provided types, and we can't (as far as I can
read_blocker: Option<futures::sync::oneshot::Sender<Result<(), ()>>>, // 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<PeerManager> 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<()>,
// When we are told by rust-lightning to disconnect, we can't return to rust-lightning until we
// are sure we won't call any more read/write PeerManager functions with the same connection.
// This is set to true if we're in such a condition (with disconnect checked before with the
// top-level mutex held) and false when we can return.
block_disconnect_socket: bool,
read_paused: bool, read_paused: bool,
need_disconnect: bool, rl_requested_disconnect: bool,
id: u64, id: u64,
} }
impl Connection { impl Connection {
fn schedule_read<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor<CMH>, Arc<CMH>>>, us: Arc<Mutex<Self>>, reader: futures::stream::SplitStream<tokio_codec::Framed<TcpStream, tokio_codec::BytesCodec>>) { fn event_trigger(us: &mut MutexGuard<Self>) {
let us_ref = us.clone(); match us.event_notify.try_send(()) {
let us_close_ref = us.clone(); 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<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor, Arc<CMH>>>, us: Arc<Mutex<Self>>, mut reader: io::ReadHalf<TcpStream>, mut read_wake_receiver: mpsc::Receiver<()>, mut write_avail_receiver: mpsc::Receiver<()>) {
let peer_manager_ref = peer_manager.clone(); let peer_manager_ref = peer_manager.clone();
tokio::spawn(reader.for_each(move |b| { // 8KB is nice and big but also should never cause any issues with stack overflowing.
let pending_read = b.to_vec(); let mut buf = [0; 8192];
{
let mut lock = us_ref.lock().unwrap(); let mut our_descriptor = SocketDescriptor::new(us.clone());
assert!(lock.pending_read.is_empty()); // An enum describing why we did/are disconnecting:
if lock.read_paused { enum Disconnect {
lock.pending_read = pending_read; // Rust-Lightning told us to disconnect, either by returning an Err or by calling
let (sender, blocker) = futures::sync::oneshot::channel(); // SocketDescriptor::disconnect_socket.
lock.read_blocker = Some(sender); // In this case, we do not call peer_manager.socket_disconnected() as Rust-Lightning
return future::Either::A(blocker.then(|_| { Ok(()) })); // 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 macro_rules! prepare_read_write_call {
//call read_event! () => { {
match peer_manager.read_event(&mut SocketDescriptor::new(us_ref.clone(), peer_manager.clone()), pending_read) { let mut us_lock = us.lock().unwrap();
Ok(pause_read) => { if us_lock.rl_requested_disconnect {
if pause_read { shutdown_socket!("disconnect_socket() call from RL", Disconnect::CloseConnection);
let mut lock = us_ref.lock().unwrap();
lock.read_paused = true;
} }
us_lock.block_disconnect_socket = 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!
prepare_read_write_call!();
if let Err(e) = peer_manager.write_buffer_space_avail(&mut our_descriptor) {
shutdown_socket!(e, Disconnect::CloseConnection);
}
us.lock().unwrap().block_disconnect_socket = false;
}, },
Err(e) => { _ = read_wake_receiver.recv() => {},
us_ref.lock().unwrap().need_disconnect = false; read = reader.read(&mut buf), if !read_paused => match read {
return future::Either::B(future::result(Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)))); Ok(0) => shutdown_socket!("Connection closed", Disconnect::PeerDisconnected),
} Ok(len) => {
} prepare_read_write_call!();
let read_res = peer_manager.read_event(&mut our_descriptor, &buf[0..len]);
if let Err(e) = us_ref.lock().unwrap().event_notify.try_send(()) { let mut us_lock = us.lock().unwrap();
// Ignore full errors as we just need them to poll after this point, so if the user match read_res {
// hasn't received the last send yet, it doesn't matter.
assert!(e.is_full());
}
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(())
}));
}
fn new(event_notify: mpsc::Sender<()>, stream: TcpStream) -> (futures::stream::SplitStream<tokio_codec::Framed<TcpStream, tokio_codec::BytesCodec>>, Arc<Mutex<Self>>) {
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 (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<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor<CMH>, Arc<CMH>>>, event_notify: mpsc::Sender<()>, stream: TcpStream) {
let (reader, us) = Self::new(event_notify, stream);
if let Ok(_) = peer_manager.new_inbound_connection(SocketDescriptor::new(us.clone(), peer_manager.clone())) {
Self::schedule_read(peer_manager, us, reader);
}
}
/// 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<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor<CMH>, Arc<CMH>>>, 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);
} else {
println!("Failed to write first full message to socket!");
}
}
}
/// 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<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor<CMH>, Arc<CMH>>>, 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(())
}));
}
}
pub struct SocketDescriptor<CMH: ChannelMessageHandler + 'static> {
conn: Arc<Mutex<Connection>>,
id: u64,
peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor<CMH>, Arc<CMH>>>,
}
impl<CMH: ChannelMessageHandler> SocketDescriptor<CMH> {
fn new(conn: Arc<Mutex<Connection>>, peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor<CMH>, Arc<CMH>>>) -> Self {
let id = conn.lock().unwrap().id;
Self { conn, id, peer_manager }
}
}
impl<CMH: ChannelMessageHandler> peer_handler::SocketDescriptor for SocketDescriptor<CMH> {
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) => { Ok(pause_read) => {
if pause_read { return Ok(()); } if pause_read {
us_lock.read_paused = true;
}
Self::event_trigger(&mut us_lock);
}, },
Err(_) => { Err(e) => shutdown_socket!(e, Disconnect::CloseConnection),
//TODO: Not actually sure how to do this }
return Ok(()); us_lock.block_disconnect_socket = false;
} },
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());
}
}
fn new(event_notify: mpsc::Sender<()>, stream: TcpStream) -> (io::ReadHalf<TcpStream>, mpsc::Receiver<()>, mpsc::Receiver<()>, Arc<Mutex<Self>>) {
// 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);
(reader, write_receiver, read_receiver,
Arc::new(Mutex::new(Self {
writer: Some(writer), event_notify, write_avail, read_waker, read_paused: false,
block_disconnect_socket: false, rl_requested_disconnect: false,
id: ID_COUNTER.fetch_add(1, Ordering::AcqRel)
})))
}
}
/// 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<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor, Arc<CMH>>>, event_notify: mpsc::Sender<()>, stream: TcpStream) -> impl std::future::Future<Output=()> {
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(_) = 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
};
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<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor, Arc<CMH>>>, event_notify: mpsc::Sender<()>, their_node_id: PublicKey, stream: TcpStream) -> impl std::future::Future<Output=()> {
let (reader, mut 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 {
// We should essentially always have enough room in a TCP socket buffer to send the
// initial 10s of bytes. However, tokio running in single-threaded mode will always
// fail writes and wake us back up later to write. Thus, we handle a single
// std::task::Poll::Pending but still expect to write the full set of bytes at once
// and use a relatively tight timeout.
if let Ok(Ok(())) = tokio::time::timeout(Duration::from_millis(100), async {
loop {
match SocketDescriptor::new(us.clone()).send_data(&initial_send, true) {
v if v == initial_send.len() => break Ok(()),
0 => {
write_receiver.recv().await;
// In theory we could check for if we've been instructed to disconnect
// the peer here, but its OK to just skip it - we'll check for it in
// schedule_read prior to any relevant calls into RL.
},
_ => {
eprintln!("Failed to write first full message to socket!");
peer_manager.socket_disconnected(&SocketDescriptor::new(Arc::clone(&us)));
break Err(());
} }
} }
let mut us = $us_ref.conn.lock().unwrap(); }
if let Some(sender) = us.read_blocker.take() { }).await {
sender.send(Ok(())).unwrap(); Connection::schedule_read(peer_manager, us, reader, read_receiver, write_receiver).await;
} }
us.read_paused = false; }))
if let Err(e) = us.event_notify.try_send(()) { } else {
// Ignore full errors as we just need them to poll after this point, so if the user // Note that we will skip socket_disconnected here, in accordance with the PeerManager
// hasn't received the last send yet, it doesn't matter. // requirements.
assert!(e.is_full()); None
} };
Ok(())
})); 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 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<CMH: ChannelMessageHandler + 'static>(peer_manager: Arc<peer_handler::PeerManager<SocketDescriptor, Arc<CMH>>>, event_notify: mpsc::Sender<()>, their_node_id: PublicKey, addr: SocketAddr) -> Option<impl std::future::Future<Output=()>> {
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 }
}
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<Mutex<Connection>>,
id: u64,
}
impl SocketDescriptor {
fn new(conn: Arc<Mutex<Connection>>) -> Self {
let id = conn.lock().unwrap().id;
Self { conn, id }
}
}
impl peer_handler::SocketDescriptor for SocketDescriptor {
fn send_data(&mut self, data: &[u8], resume_read: bool) -> usize {
// 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(); 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() { 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; return 0;
} }
let mut bytes = bytes::BytesMut::with_capacity(data.len()); if resume_read && us.read_paused {
bytes.put(data); // The schedule_read future may go to lock up but end up getting woken up by there
let write_res = us.writer.as_mut().unwrap().start_send(bytes.freeze()); // being more room in the write buffer, dropping the other end of this Sender
match write_res { // before we get here, so we ignore any failures to wake it up.
Ok(res) => { us.read_paused = false;
match res { let _ = us.read_waker.try_send(());
AsyncSink::Ready => { }
data.len() if data.is_empty() { return 0; }
}, let waker = unsafe { task::Waker::from_raw(write_avail_to_waker(&us.write_avail)) };
AsyncSink::NotReady(_) => { let mut ctx = task::Context::from_waker(&waker);
us.read_paused = true; let mut written_len = 0;
let us_ref = self.clone(); loop {
tokio::spawn(us.writer.take().unwrap().flush().then(move |writer_res| -> Result<(), ()> { match std::pin::Pin::new(us.writer.as_mut().unwrap()).poll_write(&mut ctx, &data[written_len..]) {
if let Ok(writer) = writer_res { task::Poll::Ready(Ok(res)) => {
{ // The tokio docs *seem* to indicate this can't happen, and I certainly don't
let mut us = us_ref.conn.lock().unwrap(); // know how to handle it if it does (cause it should be a Poll::Pending
us.writer = Some(writer); // instead):
} assert_ne!(res, 0);
schedule_read!(us_ref); written_len += res;
} // we'll fire the disconnect event on the socket reader end if written_len == data.len() { return written_len; }
Ok(()) },
})); task::Poll::Ready(Err(e)) => {
0 // 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);
Err(_) => { // Probably we've already been closed, just return what we have and let the
// We'll fire the disconnected event on the socket reader end // read thread handle closing logic.
0 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) { fn disconnect_socket(&mut self) {
let mut us = self.conn.lock().unwrap(); {
us.need_disconnect = true; let mut us = self.conn.lock().unwrap();
us.read_paused = 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(());
// Happy-path return:
if !us.block_disconnect_socket { return; }
}
while self.conn.lock().unwrap().block_disconnect_socket {
thread::yield_now();
}
} }
} }
impl<CMH: ChannelMessageHandler> Clone for SocketDescriptor<CMH> { impl Clone for SocketDescriptor {
fn clone(&self) -> Self { fn clone(&self) -> Self {
Self { Self {
conn: Arc::clone(&self.conn), conn: Arc::clone(&self.conn),
id: self.id, id: self.id,
peer_manager: Arc::clone(&self.peer_manager),
} }
} }
} }
impl<CMH: ChannelMessageHandler> Eq for SocketDescriptor<CMH> {} impl Eq for SocketDescriptor {}
impl<CMH: ChannelMessageHandler> PartialEq for SocketDescriptor<CMH> { impl PartialEq for SocketDescriptor {
fn eq(&self, o: &Self) -> bool { fn eq(&self, o: &Self) -> bool {
self.id == o.id self.id == o.id
} }
} }
impl<CMH: ChannelMessageHandler> Hash for SocketDescriptor<CMH> { impl Hash for SocketDescriptor {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) { fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.id.hash(state); 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<Vec<MessageSendEvent>>,
}
impl RoutingMessageHandler for MsgHandler {
fn handle_node_announcement(&self, _msg: &NodeAnnouncement) -> Result<bool, LightningError> { Ok(false) }
fn handle_channel_announcement(&self, _msg: &ChannelAnnouncement) -> Result<bool, LightningError> { Ok(false) }
fn handle_channel_update(&self, _msg: &ChannelUpdate) -> Result<bool, LightningError> { 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<NodeAnnouncement> { 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<MessageSendEvent> {
let mut ret = Vec::new();
mem::swap(&mut *self.msg_events.lock().unwrap(), &mut ret);
ret
}
}
async fn do_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<dyn RoutingMessageHandler>,
}, 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<dyn RoutingMessageHandler>,
}, 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;
}
#[tokio::test(threaded_scheduler)]
async fn basic_threaded_connection_test() {
do_basic_connection_test().await;
}
#[tokio::test]
async fn basic_unthreaded_connection_test() {
do_basic_connection_test().await;
}
}

10
lightning/src/ln/peer_handler.rs
View file

@ -445,7 +445,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref> PeerManager<Descriptor, CM> where
/// on this file descriptor has resume_read set (preventing DoS issues in the send buffer). /// on this file descriptor has resume_read set (preventing DoS issues in the send buffer).
/// ///
/// Panics if the descriptor was not previously registered in a new_*_connection event. /// Panics if the descriptor was not previously registered in a new_*_connection event.
pub fn read_event(&self, peer_descriptor: &mut Descriptor, data: Vec<u8>) -> Result<bool, PeerHandleError> { pub fn read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
match self.do_read_event(peer_descriptor, data) { match self.do_read_event(peer_descriptor, data) {
Ok(res) => Ok(res), Ok(res) => Ok(res),
Err(e) => { Err(e) => {
@ -455,7 +455,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref> PeerManager<Descriptor, CM> where
} }
} }
fn do_read_event(&self, peer_descriptor: &mut Descriptor, data: Vec<u8>) -> Result<bool, PeerHandleError> { fn do_read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
let pause_read = { let pause_read = {
let mut peers_lock = self.peers.lock().unwrap(); let mut peers_lock = self.peers.lock().unwrap();
let peers = &mut *peers_lock; let peers = &mut *peers_lock;
@ -1228,9 +1228,9 @@ mod tests {
let mut fd_b = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) }; let mut fd_b = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
let initial_data = peer_b.new_outbound_connection(a_id, fd_b.clone()).unwrap(); let initial_data = peer_b.new_outbound_connection(a_id, fd_b.clone()).unwrap();
peer_a.new_inbound_connection(fd_a.clone()).unwrap(); peer_a.new_inbound_connection(fd_a.clone()).unwrap();
assert_eq!(peer_a.read_event(&mut fd_a, initial_data).unwrap(), false); assert_eq!(peer_a.read_event(&mut fd_a, &initial_data).unwrap(), false);
assert_eq!(peer_b.read_event(&mut fd_b, fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false); assert_eq!(peer_b.read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
assert_eq!(peer_a.read_event(&mut fd_a, fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap(), false); assert_eq!(peer_a.read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
} }
#[test] #[test]