+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
//! Events are returned from various bits in the library which indicate some action must be taken
//! by the client.
//!
//! Because we don't have a built-in runtime, it's up to the client to call events at a time in the
//! future, as well as generate and broadcast funding transactions handle payment preimages and a
//! few other things.
-//!
-//! Note that many events are handled for you by PeerHandler, so in the common design of having a
-//! PeerManager which marshalls messages to ChannelManager and Router you only need to call
-//! process_events on the PeerHandler and then get_and_clear_pending_events and handle the events
-//! that bubble up to the surface. If, however, you do not have a PeerHandler managing a
-//! ChannelManager you need to handle all of the events which may be generated.
-//TODO: We need better separation of event types ^
use ln::msgs;
-use ln::channelmanager::{PaymentPreimage, PaymentHash};
-use chain::transaction::OutPoint;
+use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
use chain::keysinterface::SpendableOutputDescriptor;
+use util::ser::{Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper};
use bitcoin::blockdata::script::Script;
-use secp256k1::key::PublicKey;
+use bitcoin::secp256k1::key::PublicKey;
+
+use prelude::*;
+use core::time::Duration;
+use core::ops::Deref;
-use std::time::Duration;
+/// Some information provided on receipt of payment depends on whether the payment received is a
+/// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
+#[derive(Clone, Debug)]
+pub enum PaymentPurpose {
+ /// Information for receiving a payment that we generated an invoice for.
+ InvoicePayment {
+ /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
+ /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
+ /// [`ChannelManager::claim_funds`].
+ ///
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
+ payment_preimage: Option<PaymentPreimage>,
+ /// The "payment secret". This authenticates the sender to the recipient, preventing a
+ /// number of deanonymization attacks during the routing process.
+ /// It is provided here for your reference, however its accuracy is enforced directly by
+ /// [`ChannelManager`] using the values you previously provided to
+ /// [`ChannelManager::create_inbound_payment`] or
+ /// [`ChannelManager::create_inbound_payment_for_hash`].
+ ///
+ /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
+ payment_secret: PaymentSecret,
+ /// This is the `user_payment_id` which was provided to
+ /// [`ChannelManager::create_inbound_payment_for_hash`] or
+ /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
+ /// simply copied here. It may be used to correlate PaymentReceived events with invoice
+ /// metadata stored elsewhere.
+ ///
+ /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
+ /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
+ user_payment_id: u64,
+ },
+ /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
+ /// (the payee) providing a preimage.
+ SpontaneousPayment(PaymentPreimage),
+}
/// An Event which you should probably take some action in response to.
+///
+/// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
+/// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
+/// written as it makes no sense to respond to it after reconnecting to peers).
+#[derive(Clone, Debug)]
pub enum Event {
/// Used to indicate that the client should generate a funding transaction with the given
/// parameters and then call ChannelManager::funding_transaction_generated.
/// The value passed in to ChannelManager::create_channel
user_channel_id: u64,
},
- /// Used to indicate that the client may now broadcast the funding transaction it created for a
- /// channel. Broadcasting such a transaction prior to this event may lead to our counterparty
- /// trivially stealing all funds in the funding transaction!
- FundingBroadcastSafe {
- /// The output, which was passed to ChannelManager::funding_transaction_generated, which is
- /// now safe to broadcast.
- funding_txo: OutPoint,
- /// The value passed in to ChannelManager::create_channel
- user_channel_id: u64,
- },
/// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
/// ChannelManager::claim_funds to get it....
- /// Note that if the preimage is not known or the amount paid is incorrect, you must call
- /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC.
+ /// Note that if the preimage is not known or the amount paid is incorrect, you should call
+ /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
+ /// network congestion.
/// The amount paid should be considered 'incorrect' when it is less than or more than twice
/// the amount expected.
+ /// If you fail to call either ChannelManager::claim_funds or
+ /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
+ /// automatically failed.
PaymentReceived {
/// The hash for which the preimage should be handed to the ChannelManager.
payment_hash: PaymentHash,
/// compare this to the expected value before accepting the payment (as otherwise you are
/// providing proof-of-payment for less than the value you expected!).
amt: u64,
+ /// Information for claiming this received payment, based on whether the purpose of the
+ /// payment is to pay an invoice or to send a spontaneous payment.
+ purpose: PaymentPurpose,
},
/// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
/// and we got back the payment preimage for it).
- /// Note that duplicative PaymentSent Events may be generated - it is your responsibility to
- /// deduplicate them by payment_preimage (which MUST be unique)!
PaymentSent {
/// The preimage to the hash given to ChannelManager::send_payment.
/// Note that this serves as a payment receipt, if you wish to have such a thing, you must
},
/// Indicates an outbound payment we made failed. Probably some intermediary node dropped
/// something. You may wish to retry with a different route.
- /// Note that duplicative PaymentFailed Events may be generated - it is your responsibility to
- /// deduplicate them by payment_hash (which MUST be unique)!
PaymentFailed {
/// The hash which was given to ChannelManager::send_payment.
payment_hash: PaymentHash,
rejected_by_dest: bool,
#[cfg(test)]
error_code: Option<u16>,
+#[cfg(test)]
+ error_data: Option<Vec<u8>>,
},
/// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
/// time in the future.
/// now + 5*time_forwardable).
time_forwardable: Duration,
},
- /// Used to indicate that an output was generated on-chain which you should know how to spend.
+ /// Used to indicate that an output which you should know how to spend was confirmed on chain
+ /// and is now spendable.
/// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
/// counterparty spending them due to some kind of timeout. Thus, you need to store them
/// somewhere and spend them when you create on-chain transactions.
},
}
+impl Writeable for Event {
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ match self {
+ &Event::FundingGenerationReady { .. } => {
+ 0u8.write(writer)?;
+ // We never write out FundingGenerationReady events as, upon disconnection, peers
+ // drop any channels which have not yet exchanged funding_signed.
+ },
+ &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
+ 1u8.write(writer)?;
+ let mut payment_secret = None;
+ let mut user_payment_id = None;
+ let payment_preimage;
+ match &purpose {
+ PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
+ payment_secret = Some(secret);
+ payment_preimage = *preimage;
+ user_payment_id = Some(id);
+ },
+ PaymentPurpose::SpontaneousPayment(preimage) => {
+ payment_preimage = Some(*preimage);
+ }
+ }
+ write_tlv_fields!(writer, {
+ (0, payment_hash, required),
+ (2, payment_secret, option),
+ (4, amt, required),
+ (6, user_payment_id, option),
+ (8, payment_preimage, option),
+ });
+ },
+ &Event::PaymentSent { ref payment_preimage } => {
+ 2u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, payment_preimage, required),
+ });
+ },
+ &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
+ #[cfg(test)]
+ ref error_code,
+ #[cfg(test)]
+ ref error_data,
+ } => {
+ 3u8.write(writer)?;
+ #[cfg(test)]
+ error_code.write(writer)?;
+ #[cfg(test)]
+ error_data.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, payment_hash, required),
+ (2, rejected_by_dest, required),
+ });
+ },
+ &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
+ 4u8.write(writer)?;
+ write_tlv_fields!(writer, {});
+ // We don't write the time_fordwardable out at all, as we presume when the user
+ // deserializes us at least that much time has elapsed.
+ },
+ &Event::SpendableOutputs { ref outputs } => {
+ 5u8.write(writer)?;
+ write_tlv_fields!(writer, {
+ (0, VecWriteWrapper(outputs), required),
+ });
+ },
+ }
+ Ok(())
+ }
+}
+impl MaybeReadable for Event {
+ fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
+ match Readable::read(reader)? {
+ 0u8 => Ok(None),
+ 1u8 => {
+ let f = || {
+ let mut payment_hash = PaymentHash([0; 32]);
+ let mut payment_preimage = None;
+ let mut payment_secret = None;
+ let mut amt = 0;
+ let mut user_payment_id = None;
+ read_tlv_fields!(reader, {
+ (0, payment_hash, required),
+ (2, payment_secret, option),
+ (4, amt, required),
+ (6, user_payment_id, option),
+ (8, payment_preimage, option),
+ });
+ let purpose = match payment_secret {
+ Some(secret) => PaymentPurpose::InvoicePayment {
+ payment_preimage,
+ payment_secret: secret,
+ user_payment_id: if let Some(id) = user_payment_id {
+ id
+ } else { return Err(msgs::DecodeError::InvalidValue) }
+ },
+ None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
+ None => return Err(msgs::DecodeError::InvalidValue),
+ };
+ Ok(Some(Event::PaymentReceived {
+ payment_hash,
+ amt,
+ purpose,
+ }))
+ };
+ f()
+ },
+ 2u8 => {
+ let f = || {
+ let mut payment_preimage = PaymentPreimage([0; 32]);
+ read_tlv_fields!(reader, {
+ (0, payment_preimage, required),
+ });
+ Ok(Some(Event::PaymentSent {
+ payment_preimage,
+ }))
+ };
+ f()
+ },
+ 3u8 => {
+ let f = || {
+ #[cfg(test)]
+ let error_code = Readable::read(reader)?;
+ #[cfg(test)]
+ let error_data = Readable::read(reader)?;
+ let mut payment_hash = PaymentHash([0; 32]);
+ let mut rejected_by_dest = false;
+ read_tlv_fields!(reader, {
+ (0, payment_hash, required),
+ (2, rejected_by_dest, required),
+ });
+ Ok(Some(Event::PaymentFailed {
+ payment_hash,
+ rejected_by_dest,
+ #[cfg(test)]
+ error_code,
+ #[cfg(test)]
+ error_data,
+ }))
+ };
+ f()
+ },
+ 4u8 => {
+ let f = || {
+ read_tlv_fields!(reader, {});
+ Ok(Some(Event::PendingHTLCsForwardable {
+ time_forwardable: Duration::from_secs(0)
+ }))
+ };
+ f()
+ },
+ 5u8 => {
+ let f = || {
+ let mut outputs = VecReadWrapper(Vec::new());
+ read_tlv_fields!(reader, {
+ (0, outputs, required),
+ });
+ Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
+ };
+ f()
+ },
+ _ => Err(msgs::DecodeError::InvalidValue)
+ }
+ }
+}
+
/// An event generated by ChannelManager which indicates a message should be sent to a peer (or
/// broadcast to most peers).
/// These events are handled by PeerManager::process_events if you are using a PeerManager.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
pub enum MessageSendEvent {
/// Used to indicate that we've accepted a channel open and should send the accept_channel
/// message provided to the given peer.
},
/// Used to indicate that a channel_announcement and channel_update should be broadcast to all
/// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
+ ///
+ /// Note that after doing so, you very likely (unless you did so very recently) want to call
+ /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
+ /// This ensures that any nodes which see our channel_announcement also have a relevant
+ /// node_announcement, including relevant feature flags which may be important for routing
+ /// through or to us.
BroadcastChannelAnnouncement {
/// The channel_announcement which should be sent.
msg: msgs::ChannelAnnouncement,
/// The followup channel_update which should be sent.
update_msg: msgs::ChannelUpdate,
},
+ /// Used to indicate that a node_announcement should be broadcast to all peers.
+ BroadcastNodeAnnouncement {
+ /// The node_announcement which should be sent.
+ msg: msgs::NodeAnnouncement,
+ },
/// Used to indicate that a channel_update should be broadcast to all peers.
BroadcastChannelUpdate {
/// The channel_update which should be sent.
msg: msgs::ChannelUpdate,
},
+ /// Used to indicate that a channel_update should be sent to a single peer.
+ /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
+ /// private channel and we shouldn't be informing all of our peers of channel parameters.
+ SendChannelUpdate {
+ /// The node_id of the node which should receive this message
+ node_id: PublicKey,
+ /// The channel_update which should be sent.
+ msg: msgs::ChannelUpdate,
+ },
/// Broadcast an error downstream to be handled
HandleError {
/// The node_id of the node which should receive this message
action: msgs::ErrorAction
},
/// When a payment fails we may receive updates back from the hop where it failed. In such
- /// cases this event is generated so that we can inform the router of this information.
+ /// cases this event is generated so that we can inform the network graph of this information.
PaymentFailureNetworkUpdate {
- /// The channel/node update which should be sent to router
+ /// The channel/node update which should be sent to NetGraphMsgHandler
update: msgs::HTLCFailChannelUpdate,
+ },
+ /// Query a peer for channels with funding transaction UTXOs in a block range.
+ SendChannelRangeQuery {
+ /// The node_id of this message recipient
+ node_id: PublicKey,
+ /// The query_channel_range which should be sent.
+ msg: msgs::QueryChannelRange,
+ },
+ /// Request routing gossip messages from a peer for a list of channels identified by
+ /// their short_channel_ids.
+ SendShortIdsQuery {
+ /// The node_id of this message recipient
+ node_id: PublicKey,
+ /// The query_short_channel_ids which should be sent.
+ msg: msgs::QueryShortChannelIds,
+ },
+ /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
+ /// emitted during processing of the query.
+ SendReplyChannelRange {
+ /// The node_id of this message recipient
+ node_id: PublicKey,
+ /// The reply_channel_range which should be sent.
+ msg: msgs::ReplyChannelRange,
}
}
fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
}
-/// A trait indicating an object may generate events
+/// A trait indicating an object may generate events.
+///
+/// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
+///
+/// # Requirements
+///
+/// See [`process_pending_events`] for requirements around event processing.
+///
+/// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
+/// event since the last invocation. The handler must either act upon the event immediately
+/// or preserve it for later handling.
+///
+/// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
+/// consult the provider's documentation on the implication of processing events and how a handler
+/// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
+/// [`ChainMonitor::process_pending_events`]).
+///
+/// (C-not implementable) As there is likely no reason for a user to implement this trait on their
+/// own type(s).
+///
+/// [`process_pending_events`]: Self::process_pending_events
+/// [`handle_event`]: EventHandler::handle_event
+/// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
+/// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
pub trait EventsProvider {
- /// Gets the list of pending events which were generated by previous actions, clearing the list
- /// in the process.
- fn get_and_clear_pending_events(&self) -> Vec<Event>;
+ /// Processes any events generated since the last call using the given event handler.
+ ///
+ /// Subsequent calls must only process new events. However, handlers must be capable of handling
+ /// duplicate events across process restarts. This may occur if the provider was recovered from
+ /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
+ fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
+}
+
+/// A trait implemented for objects handling events from [`EventsProvider`].
+pub trait EventHandler {
+ /// Handles the given [`Event`].
+ ///
+ /// See [`EventsProvider`] for details that must be considered when implementing this method.
+ fn handle_event(&self, event: Event);
+}
+
+impl<F> EventHandler for F where F: Fn(Event) {
+ fn handle_event(&self, event: Event) {
+ self(event)
+ }
}
projects / rust-lightning / blobdiff