use lightning::ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
use lightning::util::logger::Logger;
-use std::{task, thread};
+use std::task;
use std::net::SocketAddr;
use std::net::TcpStream as StdTcpStream;
use std::sync::{Arc, Mutex};
// 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,
rl_requested_disconnect: bool,
id: u64,
} }
}
- macro_rules! prepare_read_write_call {
- () => { {
- let mut us_lock = us.lock().unwrap();
- if us_lock.rl_requested_disconnect {
- shutdown_socket!("disconnect_socket() call from RL", Disconnect::CloseConnection);
- }
- us_lock.block_disconnect_socket = true;
- } }
- }
-
- let read_paused = us.lock().unwrap().read_paused;
+ let read_paused = {
+ let us_lock = us.lock().unwrap();
+ if us_lock.rl_requested_disconnect {
+ shutdown_socket!("disconnect_socket() call from RL", Disconnect::CloseConnection);
+ }
+ us_lock.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;
},
_ = read_wake_receiver.recv() => {},
read = reader.read(&mut buf), if !read_paused => match read {
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]);
let mut us_lock = us.lock().unwrap();
match read_res {
},
Err(e) => shutdown_socket!(e, Disconnect::CloseConnection),
}
- us_lock.block_disconnect_socket = false;
},
Err(e) => shutdown_socket!(e, Disconnect::PeerDisconnected),
},
(reader, write_receiver, read_receiver,
Arc::new(Mutex::new(Self {
writer: Some(writer), write_avail, read_waker, read_paused: false,
- block_disconnect_socket: false, rl_requested_disconnect: false,
+ rl_requested_disconnect: false,
id: ID_COUNTER.fetch_add(1, Ordering::AcqRel)
})))
}
}
fn disconnect_socket(&mut self) {
- {
- let mut us = self.conn.lock().unwrap();
- 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();
- }
+ let mut us = self.conn.lock().unwrap();
+ us.rl_requested_disconnect = true;
+ // Wake up the sending thread, assuming it is still alive
+ let _ = us.write_avail.try_send(());
}
}
impl Clone for SocketDescriptor {
CM::Target: ChannelMessageHandler,
RM::Target: RoutingMessageHandler {
/// A message handler which handles messages specific to channels. Usually this is just a
- /// ChannelManager object or a ErroringMessageHandler.
+ /// [`ChannelManager`] object or an [`ErroringMessageHandler`].
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
pub chan_handler: CM,
/// A message handler which handles messages updating our knowledge of the network channel
- /// graph. Usually this is just a NetGraphMsgHandlerMonitor object or an IgnoringMessageHandler.
+ /// graph. Usually this is just a [`NetGraphMsgHandler`] object or an
+ /// [`IgnoringMessageHandler`].
+ ///
+ /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
pub route_handler: RM,
}
///
/// For efficiency, Clone should be relatively cheap for this type.
///
-/// You probably want to just extend an int and put a file descriptor in a struct and implement
-/// send_data. Note that if you are using a higher-level net library that may call close() itself,
-/// be careful to ensure you don't have races whereby you might register a new connection with an
-/// fd which is the same as a previous one which has yet to be removed via
-/// PeerManager::socket_disconnected().
+/// Two descriptors may compare equal (by [`cmp::Eq`] and [`hash::Hash`]) as long as the original
+/// has been disconnected, the [`PeerManager`] has been informed of the disconnection (either by it
+/// having triggered the disconnection or a call to [`PeerManager::socket_disconnected`]), and no
+/// further calls to the [`PeerManager`] related to the original socket occur. This allows you to
+/// use a file descriptor for your SocketDescriptor directly, however for simplicity you may wish
+/// to simply use another value which is guaranteed to be globally unique instead.
pub trait SocketDescriptor : cmp::Eq + hash::Hash + Clone {
/// Attempts to send some data from the given slice to the peer.
///
/// Returns the amount of data which was sent, possibly 0 if the socket has since disconnected.
- /// Note that in the disconnected case, socket_disconnected must still fire and further write
- /// attempts may occur until that time.
+ /// Note that in the disconnected case, [`PeerManager::socket_disconnected`] must still be
+ /// called and further write attempts may occur until that time.
///
- /// If the returned size is smaller than data.len(), a write_available event must
- /// trigger the next time more data can be written. Additionally, until the a send_data event
- /// completes fully, no further read_events should trigger on the same peer!
+ /// If the returned size is smaller than `data.len()`, a
+ /// [`PeerManager::write_buffer_space_avail`] call must be made the next time more data can be
+ /// written. Additionally, until a `send_data` event completes fully, no further
+ /// [`PeerManager::read_event`] calls should be made for the same peer! Because this is to
+ /// prevent denial-of-service issues, you should not read or buffer any data from the socket
+ /// until then.
///
- /// If a read_event on this descriptor had previously returned true (indicating that read
- /// events should be paused to prevent DoS in the send buffer), resume_read may be set
- /// indicating that read events on this descriptor should resume. A resume_read of false does
- /// *not* imply that further read events should be paused.
+ /// If a [`PeerManager::read_event`] call on this descriptor had previously returned true
+ /// (indicating that read events should be paused to prevent DoS in the send buffer),
+ /// `resume_read` may be set indicating that read events on this descriptor should resume. A
+ /// `resume_read` of false carries no meaning, and should not cause any action.
fn send_data(&mut self, data: &[u8], resume_read: bool) -> usize;
- /// Disconnect the socket pointed to by this SocketDescriptor. Once this function returns, no
- /// more calls to write_buffer_space_avail, read_event or socket_disconnected may be made with
- /// this descriptor. No socket_disconnected call should be generated as a result of this call,
- /// though races may occur whereby disconnect_socket is called after a call to
- /// socket_disconnected but prior to socket_disconnected returning.
+ /// Disconnect the socket pointed to by this SocketDescriptor.
+ ///
+ /// You do *not* need to call [`PeerManager::socket_disconnected`] with this socket after this
+ /// call (doing so is a noop).
fn disconnect_socket(&mut self);
}
/// helps with issues such as long function definitions.
pub type SimpleRefPeerManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, SD, M, T, F, C, L> = PeerManager<SD, SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L>, &'e NetGraphMsgHandler<&'g C, &'f L>, &'f L>;
-/// A PeerManager manages a set of peers, described by their SocketDescriptor and marshalls socket
-/// events into messages which it passes on to its MessageHandlers.
+/// A PeerManager manages a set of peers, described by their [`SocketDescriptor`] and marshalls
+/// socket events into messages which it passes on to its [`MessageHandler`].
+///
+/// Locks are taken internally, so you must never assume that reentrancy from a
+/// [`SocketDescriptor`] call back into [`PeerManager`] methods will not deadlock.
+///
+/// Calls to [`read_event`] will decode relevant messages and pass them to the
+/// [`ChannelMessageHandler`], likely doing message processing in-line. Thus, the primary form of
+/// parallelism in Rust-Lightning is in calls to [`read_event`]. Note, however, that calls to any
+/// [`PeerManager`] functions related to the same connection must occur only in serial, making new
+/// calls only after previous ones have returned.
///
/// Rather than using a plain PeerManager, it is preferable to use either a SimpleArcPeerManager
/// a SimpleRefPeerManager, for conciseness. See their documentation for more details, but
/// essentially you should default to using a SimpleRefPeerManager, and use a
/// SimpleArcPeerManager when you require a PeerManager with a static lifetime, such as when
/// you're using lightning-net-tokio.
+///
+/// [`read_event`]: PeerManager::read_event
pub struct PeerManager<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> where
CM::Target: ChannelMessageHandler,
RM::Target: RoutingMessageHandler,
}
}
-/// Manages and reacts to connection events. You probably want to use file descriptors as PeerIds.
-/// PeerIds may repeat, but only after socket_disconnected() has been called.
impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<Descriptor, CM, RM, L> where
CM::Target: ChannelMessageHandler,
RM::Target: RoutingMessageHandler,
///
/// Returns a small number of bytes to send to the remote node (currently always 50).
///
- /// Panics if descriptor is duplicative with some other descriptor which has not yet had a
- /// socket_disconnected().
+ /// Panics if descriptor is duplicative with some other descriptor which has not yet been
+ /// [`socket_disconnected()`].
+ ///
+ /// [`socket_disconnected()`]: PeerManager::socket_disconnected
pub fn new_outbound_connection(&self, their_node_id: PublicKey, descriptor: Descriptor) -> Result<Vec<u8>, PeerHandleError> {
let mut peer_encryptor = PeerChannelEncryptor::new_outbound(their_node_id.clone(), self.get_ephemeral_key());
let res = peer_encryptor.get_act_one().to_vec();
/// call socket_disconnected for the new descriptor but must disconnect the connection
/// immediately.
///
- /// Panics if descriptor is duplicative with some other descriptor which has not yet had
- /// socket_disconnected called.
+ /// Panics if descriptor is duplicative with some other descriptor which has not yet been
+ /// [`socket_disconnected()`].
+ ///
+ /// [`socket_disconnected()`]: PeerManager::socket_disconnected
pub fn new_inbound_connection(&self, descriptor: Descriptor) -> Result<(), PeerHandleError> {
let peer_encryptor = PeerChannelEncryptor::new_inbound(&self.our_node_secret);
let pending_read_buffer = [0; 50].to_vec(); // Noise act one is 50 bytes
///
/// May return an Err to indicate that the connection should be closed.
///
- /// Will most likely call send_data on the descriptor passed in (or the descriptor handed into
- /// new_*\_connection) before returning. Thus, be very careful with reentrancy issues! The
- /// invariants around calling write_buffer_space_avail in case a write did not fully complete
- /// must still hold - be ready to call write_buffer_space_avail again if a write call generated
- /// here isn't sufficient! Panics if the descriptor was not previously registered in a
- /// new_\*_connection event.
+ /// May call [`send_data`] on the descriptor passed in (or an equal descriptor) before
+ /// returning. Thus, be very careful with reentrancy issues! The invariants around calling
+ /// [`write_buffer_space_avail`] in case a write did not fully complete must still hold - be
+ /// ready to call `[write_buffer_space_avail`] again if a write call generated here isn't
+ /// sufficient!
+ ///
+ /// [`send_data`]: SocketDescriptor::send_data
+ /// [`write_buffer_space_avail`]: PeerManager::write_buffer_space_avail
pub fn write_buffer_space_avail(&self, descriptor: &mut Descriptor) -> Result<(), PeerHandleError> {
let mut peers = self.peers.lock().unwrap();
match peers.peers.get_mut(descriptor) {
- None => panic!("Descriptor for write_event is not already known to PeerManager"),
+ None => {
+ // This is most likely a simple race condition where the user found that the socket
+ // was writeable, then we told the user to `disconnect_socket()`, then they called
+ // this method. Return an error to make sure we get disconnected.
+ return Err(PeerHandleError { no_connection_possible: false });
+ },
Some(peer) => {
peer.awaiting_write_event = false;
self.do_attempt_write_data(descriptor, peer);
///
/// May return an Err to indicate that the connection should be closed.
///
- /// Will *not* call back into send_data on any descriptors to avoid reentrancy complexity.
- /// Thus, however, you almost certainly want to call process_events() after any read_event to
- /// generate send_data calls to handle responses.
+ /// Will *not* call back into [`send_data`] on any descriptors to avoid reentrancy complexity.
+ /// Thus, however, you should call [`process_events`] after any `read_event` to generate
+ /// [`send_data`] calls to handle responses.
///
- /// If Ok(true) is returned, further read_events should not be triggered until a send_data call
- /// on this file descriptor has resume_read set (preventing DoS issues in the send buffer).
+ /// If `Ok(true)` is returned, further read_events should not be triggered until a
+ /// [`send_data`] call on this 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.
+ /// [`send_data`]: SocketDescriptor::send_data
+ /// [`process_events`]: PeerManager::process_events
pub fn read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
match self.do_read_event(peer_descriptor, data) {
Ok(res) => Ok(res),
let mut msgs_to_forward = Vec::new();
let mut peer_node_id = None;
let pause_read = match peers.peers.get_mut(peer_descriptor) {
- None => panic!("Descriptor for read_event is not already known to PeerManager"),
+ None => {
+ // This is most likely a simple race condition where the user read some bytes
+ // from the socket, then we told the user to `disconnect_socket()`, then they
+ // called this method. Return an error to make sure we get disconnected.
+ return Err(PeerHandleError { no_connection_possible: false });
+ },
Some(peer) => {
assert!(peer.pending_read_buffer.len() > 0);
assert!(peer.pending_read_buffer.len() > peer.pending_read_buffer_pos);
/// Checks for any events generated by our handlers and processes them. Includes sending most
/// response messages as well as messages generated by calls to handler functions directly (eg
- /// functions like ChannelManager::process_pending_htlc_forward or send_payment).
+ /// functions like [`ChannelManager::process_pending_htlc_forwards`] or [`send_payment`]).
+ ///
+ /// May call [`send_data`] on [`SocketDescriptor`]s. Thus, be very careful with reentrancy
+ /// issues!
+ ///
+ /// [`send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
+ /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
+ /// [`send_data`]: SocketDescriptor::send_data
pub fn process_events(&self) {
{
// TODO: There are some DoS attacks here where you can flood someone's outbound send
}
/// Indicates that the given socket descriptor's connection is now closed.
- ///
- /// This must only be called if the socket has been disconnected by the peer or your own
- /// decision to disconnect it and must NOT be called in any case where other parts of this
- /// library (eg PeerHandleError, explicit disconnect_socket calls) instruct you to disconnect
- /// the peer.
- ///
- /// Panics if the descriptor was not previously registered in a successful new_*_connection event.
pub fn socket_disconnected(&self, descriptor: &Descriptor) {
self.disconnect_event_internal(descriptor, false);
}
let mut peers = self.peers.lock().unwrap();
let peer_option = peers.peers.remove(descriptor);
match peer_option {
- None => panic!("Descriptor for disconnect_event is not already known to PeerManager"),
+ None => {
+ // This is most likely a simple race condition where the user found that the socket
+ // was disconnected, then we told the user to `disconnect_socket()`, then they
+ // called this method. Either way we're disconnected, return.
+ },
Some(peer) => {
match peer.their_node_id {
Some(node_id) => {
/// Disconnect a peer given its node id.
///
- /// Set no_connection_possible to true to prevent any further connection with this peer,
+ /// Set `no_connection_possible` to true to prevent any further connection with this peer,
/// force-closing any channels we have with it.
///
- /// If a peer is connected, this will call `disconnect_socket` on the descriptor for the peer,
- /// so be careful about reentrancy issues.
+ /// If a peer is connected, this will call [`disconnect_socket`] on the descriptor for the
+ /// peer. Thus, be very careful about reentrancy issues.
+ ///
+ /// [`disconnect_socket`]: SocketDescriptor::disconnect_socket
pub fn disconnect_by_node_id(&self, node_id: PublicKey, no_connection_possible: bool) {
let mut peers_lock = self.peers.lock().unwrap();
if let Some(mut descriptor) = peers_lock.node_id_to_descriptor.remove(&node_id) {
}
/// This function should be called roughly once every 30 seconds.
- /// It will send pings to each peer and disconnect those which did not respond to the last round of pings.
-
- /// Will most likely call send_data on all of the registered descriptors, thus, be very careful with reentrancy issues!
+ /// It will send pings to each peer and disconnect those which did not respond to the last
+ /// round of pings.
+ ///
+ /// May call [`send_data`] on all [`SocketDescriptor`]s. Thus, be very careful with reentrancy
+ /// issues!
+ ///
+ /// [`send_data`]: SocketDescriptor::send_data
pub fn timer_tick_occurred(&self) {
let mut peers_lock = self.peers.lock().unwrap();
{
projects / rust-lightning / commitdiff