X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Futil%2Fevents.rs;h=34b0b331e9e45d3512c6b65b41fd146904e735b0;hb=2024c5e1049ef399fb24e5c466924f980e949c69;hp=8b8cc1230372821aa52c0cd4e6edbdc01cb5f1bd;hpb=affefb677e3f9f1a586707484ac82b6c86f4f26b;p=rust-lightning diff --git a/lightning/src/util/events.rs b/lightning/src/util/events.rs index 8b8cc123..34b0b331 100644 --- a/lightning/src/util/events.rs +++ b/lightning/src/util/events.rs @@ -15,15 +15,56 @@ //! few other things. use ln::msgs; -use ln::channelmanager::{PaymentPreimage, PaymentHash, PaymentSecret}; +use ln::{PaymentPreimage, PaymentHash, PaymentSecret}; use chain::keysinterface::SpendableOutputDescriptor; -use util::ser::{Writeable, Writer, MaybeReadable, Readable}; +use util::ser::{Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper}; use bitcoin::blockdata::script::Script; use bitcoin::secp256k1::key::PublicKey; -use std::time::Duration; +use prelude::*; +use core::time::Duration; +use core::ops::Deref; + +/// 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. /// @@ -61,25 +102,16 @@ pub enum Event { PaymentReceived { /// The hash for which the preimage should be handed to the ChannelManager. payment_hash: PaymentHash, - /// The "payment secret". This authenticates the sender to the recipient, preventing a - /// number of deanonymization attacks during the routing process. - /// As nodes upgrade, the invoices you provide should likely migrate to setting the - /// payment_secret feature to required, at which point you should fail_backwards any HTLCs - /// which have a None here. - /// Until then, however, values of None should be ignored, and only incorrect Some values - /// should result in an HTLC fail_backwards. - /// Note that, in any case, this value must be passed as-is to any fail or claim calls as - /// the HTLC index includes this value. - payment_secret: Option, /// The value, in thousandths of a satoshi, that this payment is for. Note that you must /// 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 @@ -88,8 +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, @@ -111,7 +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. @@ -119,6 +150,27 @@ pub enum Event { /// The outputs which you should store as spendable by you. outputs: Vec, }, + /// This event is generated when a payment has been successfully forwarded through us and a + /// forwarding fee earned. + PaymentForwarded { + /// The fee, in milli-satoshis, which was earned as a result of the payment. + /// + /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC + /// was pending, the amount the next hop claimed will have been rounded down to the nearest + /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still + /// claimed the full value in millisatoshis from the source. In this case, + /// `claim_from_onchain_tx` will be set. + /// + /// If the channel which sent us the payment has been force-closed, we will claim the funds + /// via an on-chain transaction. In that case we do not yet know the on-chain transaction + /// fees which we will spend and will instead set this to `None`. It is possible duplicate + /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is + /// `None`. + fee_earned_msat: Option, + /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain + /// transaction. + claim_from_onchain_tx: bool, + }, } impl Writeable for Event { @@ -129,15 +181,34 @@ impl Writeable for Event { // 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 payment_secret, ref amt } => { + &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => { 1u8.write(writer)?; - payment_hash.write(writer)?; - payment_secret.write(writer)?; - amt.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)?; - payment_preimage.write(writer)?; + write_tlv_fields!(writer, { + (0, payment_preimage, required), + }); }, &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest, #[cfg(test)] @@ -146,24 +217,33 @@ impl Writeable for Event { ref error_data, } => { 3u8.write(writer)?; - payment_hash.write(writer)?; - rejected_by_dest.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)?; - (outputs.len() as u64).write(writer)?; - for output in outputs.iter() { - output.write(writer)?; - } + write_tlv_fields!(writer, { + (0, VecWriteWrapper(outputs), required), + }); + }, + &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => { + 7u8.write(writer)?; + write_tlv_fields!(writer, { + (0, fee_earned_msat, option), + (2, claim_from_onchain_tx, required), + }); }, } Ok(()) @@ -173,33 +253,107 @@ impl MaybeReadable for Event { fn read(reader: &mut R) -> Result, msgs::DecodeError> { match Readable::read(reader)? { 0u8 => Ok(None), - 1u8 => Ok(Some(Event::PaymentReceived { - payment_hash: Readable::read(reader)?, - payment_secret: Readable::read(reader)?, - amt: Readable::read(reader)?, - })), - 2u8 => Ok(Some(Event::PaymentSent { - payment_preimage: Readable::read(reader)?, - })), - 3u8 => Ok(Some(Event::PaymentFailed { - payment_hash: Readable::read(reader)?, - rejected_by_dest: Readable::read(reader)?, + 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)] - error_code: Readable::read(reader)?, + let error_code = Readable::read(reader)?; #[cfg(test)] - error_data: Readable::read(reader)?, - })), - 4u8 => Ok(Some(Event::PendingHTLCsForwardable { - time_forwardable: Duration::from_secs(0) - })), + 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 outputs_len: u64 = Readable::read(reader)?; - let mut outputs = Vec::new(); - for _ in 0..outputs_len { - outputs.push(Readable::read(reader)?); - } - Ok(Some(Event::SpendableOutputs { outputs })) + let f = || { + let mut outputs = VecReadWrapper(Vec::new()); + read_tlv_fields!(reader, { + (0, outputs, required), + }); + Ok(Some(Event::SpendableOutputs { outputs: outputs.0 })) + }; + f() + }, + 7u8 => { + let f = || { + let mut fee_earned_msat = None; + let mut claim_from_onchain_tx = false; + read_tlv_fields!(reader, { + (0, fee_earned_msat, option), + (2, claim_from_onchain_tx, required), + }); + Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx })) + }; + f() }, + // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue. + x if x % 2 == 1 => Ok(None), _ => Err(msgs::DecodeError::InvalidValue) } } @@ -314,6 +468,15 @@ pub enum MessageSendEvent { /// 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 @@ -359,9 +522,49 @@ 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) + } }