X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fevents.rs;h=876dfe6abb551f359a6c67c60fe05c1d104b81ed;hb=d1e8d9ced595efe1dbcddde480fccc0d3f98184d;hp=eda6fc7ee4eab89068a0b7f7a5848c5a3d2e2810;hpb=6c9180f9729cb9785892cc2d844dcc42821d6ff9;p=rust-lightning diff --git a/lightning/src/util/events.rs b/lightning/src/util/events.rs index eda6fc7e..876dfe6a 100644 --- a/lightning/src/util/events.rs +++ b/lightning/src/util/events.rs @@ -1,29 +1,77 @@ +// This file is Copyright its original authors, visible in version control +// history. +// +// This file is licensed under the Apache License, Version 2.0 or the MIT license +// , 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, + /// 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. @@ -41,22 +89,16 @@ pub enum Event { /// 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, @@ -64,11 +106,12 @@ pub enum Event { /// 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 @@ -77,8 +120,6 @@ pub enum Event { }, /// 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, @@ -88,6 +129,8 @@ pub enum Event { rejected_by_dest: bool, #[cfg(test)] error_code: Option, +#[cfg(test)] + error_data: Option>, }, /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a /// time in the future. @@ -98,7 +141,8 @@ pub enum Event { /// 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. @@ -108,10 +152,175 @@ pub enum Event { }, } +impl Writeable for Event { + fn write(&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(reader: &mut R) -> Result, 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. @@ -195,17 +404,37 @@ pub enum MessageSendEvent { }, /// 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 @@ -214,10 +443,33 @@ pub enum MessageSendEvent { 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, } } @@ -228,9 +480,49 @@ pub trait MessageSendEventsProvider { fn get_and_clear_pending_msg_events(&self) -> Vec; } -/// 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; + /// 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(&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 EventHandler for F where F: Fn(Event) { + fn handle_event(&self, event: Event) { + self(event) + } }