X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannelmanager.rs;h=fa8a0b2163d2ffcb828d34c07675f8ee823e9e99;hb=1d9e541c5766eb03dfaee7844b27b3bc1d60a05e;hp=3ab5911f560c2f789baca46691ea2baa1476993b;hpb=2edc5b2865560fcafdf2b95faa04b6ca8d522f6f;p=rust-lightning diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index 3ab5911f..fa8a0b21 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -903,7 +903,7 @@ pub(super) struct PeerState where SP::Target: SignerProvider { /// The peer is currently connected (i.e. we've seen a /// [`ChannelMessageHandler::peer_connected`] and no corresponding /// [`ChannelMessageHandler::peer_disconnected`]. - is_connected: bool, + pub is_connected: bool, } impl PeerState where SP::Target: SignerProvider { @@ -1109,11 +1109,620 @@ where fn get_cm(&self) -> &ChannelManager { self } } -/// Manager which keeps track of a number of channels and sends messages to the appropriate -/// channel, also tracking HTLC preimages and forwarding onion packets appropriately. +/// A lightning node's channel state machine and payment management logic, which facilitates +/// sending, forwarding, and receiving payments through lightning channels. /// -/// Implements [`ChannelMessageHandler`], handling the multi-channel parts and passing things through -/// to individual Channels. +/// [`ChannelManager`] is parameterized by a number of components to achieve this. +/// - [`chain::Watch`] (typically [`ChainMonitor`]) for on-chain monitoring and enforcement of each +/// channel +/// - [`BroadcasterInterface`] for broadcasting transactions related to opening, funding, and +/// closing channels +/// - [`EntropySource`] for providing random data needed for cryptographic operations +/// - [`NodeSigner`] for cryptographic operations scoped to the node +/// - [`SignerProvider`] for providing signers whose operations are scoped to individual channels +/// - [`FeeEstimator`] to determine transaction fee rates needed to have a transaction mined in a +/// timely manner +/// - [`Router`] for finding payment paths when initiating and retrying payments +/// - [`Logger`] for logging operational information of varying degrees +/// +/// Additionally, it implements the following traits: +/// - [`ChannelMessageHandler`] to handle off-chain channel activity from peers +/// - [`MessageSendEventsProvider`] to similarly send such messages to peers +/// - [`OffersMessageHandler`] for BOLT 12 message handling and sending +/// - [`EventsProvider`] to generate user-actionable [`Event`]s +/// - [`chain::Listen`] and [`chain::Confirm`] for notification of on-chain activity +/// +/// Thus, [`ChannelManager`] is typically used to parameterize a [`MessageHandler`] and an +/// [`OnionMessenger`]. The latter is required to support BOLT 12 functionality. +/// +/// # `ChannelManager` vs `ChannelMonitor` +/// +/// It's important to distinguish between the *off-chain* management and *on-chain* enforcement of +/// lightning channels. [`ChannelManager`] exchanges messages with peers to manage the off-chain +/// state of each channel. During this process, it generates a [`ChannelMonitor`] for each channel +/// and a [`ChannelMonitorUpdate`] for each relevant change, notifying its parameterized +/// [`chain::Watch`] of them. +/// +/// An implementation of [`chain::Watch`], such as [`ChainMonitor`], is responsible for aggregating +/// these [`ChannelMonitor`]s and applying any [`ChannelMonitorUpdate`]s to them. It then monitors +/// for any pertinent on-chain activity, enforcing claims as needed. +/// +/// This division of off-chain management and on-chain enforcement allows for interesting node +/// setups. For instance, on-chain enforcement could be moved to a separate host or have added +/// redundancy, possibly as a watchtower. See [`chain::Watch`] for the relevant interface. +/// +/// # Initialization +/// +/// Use [`ChannelManager::new`] with the most recent [`BlockHash`] when creating a fresh instance. +/// Otherwise, if restarting, construct [`ChannelManagerReadArgs`] with the necessary parameters and +/// references to any deserialized [`ChannelMonitor`]s that were previously persisted. Use this to +/// deserialize the [`ChannelManager`] and feed it any new chain data since it was last online, as +/// detailed in the [`ChannelManagerReadArgs`] documentation. +/// +/// ``` +/// use bitcoin::BlockHash; +/// use bitcoin::network::constants::Network; +/// use lightning::chain::BestBlock; +/// # use lightning::chain::channelmonitor::ChannelMonitor; +/// use lightning::ln::channelmanager::{ChainParameters, ChannelManager, ChannelManagerReadArgs}; +/// # use lightning::routing::gossip::NetworkGraph; +/// use lightning::util::config::UserConfig; +/// use lightning::util::ser::ReadableArgs; +/// +/// # fn read_channel_monitors() -> Vec> { vec![] } +/// # fn example< +/// # 'a, +/// # L: lightning::util::logger::Logger, +/// # ES: lightning::sign::EntropySource, +/// # S: for <'b> lightning::routing::scoring::LockableScore<'b, ScoreLookUp = SL>, +/// # SL: lightning::routing::scoring::ScoreLookUp, +/// # SP: Sized, +/// # R: lightning::io::Read, +/// # >( +/// # fee_estimator: &dyn lightning::chain::chaininterface::FeeEstimator, +/// # chain_monitor: &dyn lightning::chain::Watch, +/// # tx_broadcaster: &dyn lightning::chain::chaininterface::BroadcasterInterface, +/// # router: &lightning::routing::router::DefaultRouter<&NetworkGraph<&'a L>, &'a L, &ES, &S, SP, SL>, +/// # logger: &L, +/// # entropy_source: &ES, +/// # node_signer: &dyn lightning::sign::NodeSigner, +/// # signer_provider: &lightning::sign::DynSignerProvider, +/// # best_block: lightning::chain::BestBlock, +/// # current_timestamp: u32, +/// # mut reader: R, +/// # ) -> Result<(), lightning::ln::msgs::DecodeError> { +/// // Fresh start with no channels +/// let params = ChainParameters { +/// network: Network::Bitcoin, +/// best_block, +/// }; +/// let default_config = UserConfig::default(); +/// let channel_manager = ChannelManager::new( +/// fee_estimator, chain_monitor, tx_broadcaster, router, logger, entropy_source, node_signer, +/// signer_provider, default_config, params, current_timestamp +/// ); +/// +/// // Restart from deserialized data +/// let mut channel_monitors = read_channel_monitors(); +/// let args = ChannelManagerReadArgs::new( +/// entropy_source, node_signer, signer_provider, fee_estimator, chain_monitor, tx_broadcaster, +/// router, logger, default_config, channel_monitors.iter_mut().collect() +/// ); +/// let (block_hash, channel_manager) = +/// <(BlockHash, ChannelManager<_, _, _, _, _, _, _, _>)>::read(&mut reader, args)?; +/// +/// // Update the ChannelManager and ChannelMonitors with the latest chain data +/// // ... +/// +/// // Move the monitors to the ChannelManager's chain::Watch parameter +/// for monitor in channel_monitors { +/// chain_monitor.watch_channel(monitor.get_funding_txo().0, monitor); +/// } +/// # Ok(()) +/// # } +/// ``` +/// +/// # Operation +/// +/// The following is required for [`ChannelManager`] to function properly: +/// - Handle messages from peers using its [`ChannelMessageHandler`] implementation (typically +/// called by [`PeerManager::read_event`] when processing network I/O) +/// - Send messages to peers obtained via its [`MessageSendEventsProvider`] implementation +/// (typically initiated when [`PeerManager::process_events`] is called) +/// - Feed on-chain activity using either its [`chain::Listen`] or [`chain::Confirm`] implementation +/// as documented by those traits +/// - Perform any periodic channel and payment checks by calling [`timer_tick_occurred`] roughly +/// every minute +/// - Persist to disk whenever [`get_and_clear_needs_persistence`] returns `true` using a +/// [`Persister`] such as a [`KVStore`] implementation +/// - Handle [`Event`]s obtained via its [`EventsProvider`] implementation +/// +/// The [`Future`] returned by [`get_event_or_persistence_needed_future`] is useful in determining +/// when the last two requirements need to be checked. +/// +/// The [`lightning-block-sync`] and [`lightning-transaction-sync`] crates provide utilities that +/// simplify feeding in on-chain activity using the [`chain::Listen`] and [`chain::Confirm`] traits, +/// respectively. The remaining requirements can be met using the [`lightning-background-processor`] +/// crate. For languages other than Rust, the availability of similar utilities may vary. +/// +/// # Channels +/// +/// [`ChannelManager`]'s primary function involves managing a channel state. Without channels, +/// payments can't be sent. Use [`list_channels`] or [`list_usable_channels`] for a snapshot of the +/// currently open channels. +/// +/// ``` +/// # use lightning::ln::channelmanager::AChannelManager; +/// # +/// # fn example(channel_manager: T) { +/// # let channel_manager = channel_manager.get_cm(); +/// let channels = channel_manager.list_usable_channels(); +/// for details in channels { +/// println!("{:?}", details); +/// } +/// # } +/// ``` +/// +/// Each channel is identified using a [`ChannelId`], which will change throughout the channel's +/// life cycle. Additionally, channels are assigned a `user_channel_id`, which is given in +/// [`Event`]s associated with the channel and serves as a fixed identifier but is otherwise unused +/// by [`ChannelManager`]. +/// +/// ## Opening Channels +/// +/// To an open a channel with a peer, call [`create_channel`]. This will initiate the process of +/// opening an outbound channel, which requires self-funding when handling +/// [`Event::FundingGenerationReady`]. +/// +/// ``` +/// # use bitcoin::{ScriptBuf, Transaction}; +/// # use bitcoin::secp256k1::PublicKey; +/// # use lightning::ln::channelmanager::AChannelManager; +/// # use lightning::events::{Event, EventsProvider}; +/// # +/// # trait Wallet { +/// # fn create_funding_transaction( +/// # &self, _amount_sats: u64, _output_script: ScriptBuf +/// # ) -> Transaction; +/// # } +/// # +/// # fn example(channel_manager: T, wallet: W, peer_id: PublicKey) { +/// # let channel_manager = channel_manager.get_cm(); +/// let value_sats = 1_000_000; +/// let push_msats = 10_000_000; +/// match channel_manager.create_channel(peer_id, value_sats, push_msats, 42, None, None) { +/// Ok(channel_id) => println!("Opening channel {}", channel_id), +/// Err(e) => println!("Error opening channel: {:?}", e), +/// } +/// +/// // On the event processing thread once the peer has responded +/// channel_manager.process_pending_events(&|event| match event { +/// Event::FundingGenerationReady { +/// temporary_channel_id, counterparty_node_id, channel_value_satoshis, output_script, +/// user_channel_id, .. +/// } => { +/// assert_eq!(user_channel_id, 42); +/// let funding_transaction = wallet.create_funding_transaction( +/// channel_value_satoshis, output_script +/// ); +/// match channel_manager.funding_transaction_generated( +/// &temporary_channel_id, &counterparty_node_id, funding_transaction +/// ) { +/// Ok(()) => println!("Funding channel {}", temporary_channel_id), +/// Err(e) => println!("Error funding channel {}: {:?}", temporary_channel_id, e), +/// } +/// }, +/// Event::ChannelPending { channel_id, user_channel_id, former_temporary_channel_id, .. } => { +/// assert_eq!(user_channel_id, 42); +/// println!( +/// "Channel {} now {} pending (funding transaction has been broadcasted)", channel_id, +/// former_temporary_channel_id.unwrap() +/// ); +/// }, +/// Event::ChannelReady { channel_id, user_channel_id, .. } => { +/// assert_eq!(user_channel_id, 42); +/// println!("Channel {} ready", channel_id); +/// }, +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// +/// ## Accepting Channels +/// +/// Inbound channels are initiated by peers and are automatically accepted unless [`ChannelManager`] +/// has [`UserConfig::manually_accept_inbound_channels`] set. In that case, the channel may be +/// either accepted or rejected when handling [`Event::OpenChannelRequest`]. +/// +/// ``` +/// # use bitcoin::secp256k1::PublicKey; +/// # use lightning::ln::channelmanager::AChannelManager; +/// # use lightning::events::{Event, EventsProvider}; +/// # +/// # fn is_trusted(counterparty_node_id: PublicKey) -> bool { +/// # // ... +/// # unimplemented!() +/// # } +/// # +/// # fn example(channel_manager: T) { +/// # let channel_manager = channel_manager.get_cm(); +/// channel_manager.process_pending_events(&|event| match event { +/// Event::OpenChannelRequest { temporary_channel_id, counterparty_node_id, .. } => { +/// if !is_trusted(counterparty_node_id) { +/// match channel_manager.force_close_without_broadcasting_txn( +/// &temporary_channel_id, &counterparty_node_id +/// ) { +/// Ok(()) => println!("Rejecting channel {}", temporary_channel_id), +/// Err(e) => println!("Error rejecting channel {}: {:?}", temporary_channel_id, e), +/// } +/// return; +/// } +/// +/// let user_channel_id = 43; +/// match channel_manager.accept_inbound_channel( +/// &temporary_channel_id, &counterparty_node_id, user_channel_id +/// ) { +/// Ok(()) => println!("Accepting channel {}", temporary_channel_id), +/// Err(e) => println!("Error accepting channel {}: {:?}", temporary_channel_id, e), +/// } +/// }, +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// +/// ## Closing Channels +/// +/// There are two ways to close a channel: either cooperatively using [`close_channel`] or +/// unilaterally using [`force_close_broadcasting_latest_txn`]. The former is ideal as it makes for +/// lower fees and immediate access to funds. However, the latter may be necessary if the +/// counterparty isn't behaving properly or has gone offline. [`Event::ChannelClosed`] is generated +/// once the channel has been closed successfully. +/// +/// ``` +/// # use bitcoin::secp256k1::PublicKey; +/// # use lightning::ln::ChannelId; +/// # use lightning::ln::channelmanager::AChannelManager; +/// # use lightning::events::{Event, EventsProvider}; +/// # +/// # fn example( +/// # channel_manager: T, channel_id: ChannelId, counterparty_node_id: PublicKey +/// # ) { +/// # let channel_manager = channel_manager.get_cm(); +/// match channel_manager.close_channel(&channel_id, &counterparty_node_id) { +/// Ok(()) => println!("Closing channel {}", channel_id), +/// Err(e) => println!("Error closing channel {}: {:?}", channel_id, e), +/// } +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::ChannelClosed { channel_id, user_channel_id, .. } => { +/// assert_eq!(user_channel_id, 42); +/// println!("Channel {} closed", channel_id); +/// }, +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// +/// # Payments +/// +/// [`ChannelManager`] is responsible for sending, forwarding, and receiving payments through its +/// channels. A payment is typically initiated from a [BOLT 11] invoice or a [BOLT 12] offer, though +/// spontaneous (i.e., keysend) payments are also possible. Incoming payments don't require +/// maintaining any additional state as [`ChannelManager`] can reconstruct the [`PaymentPreimage`] +/// from the [`PaymentSecret`]. Sending payments, however, require tracking in order to retry failed +/// HTLCs. +/// +/// After a payment is initiated, it will appear in [`list_recent_payments`] until a short time +/// after either an [`Event::PaymentSent`] or [`Event::PaymentFailed`] is handled. Failed HTLCs +/// for a payment will be retried according to the payment's [`Retry`] strategy or until +/// [`abandon_payment`] is called. +/// +/// ## BOLT 11 Invoices +/// +/// The [`lightning-invoice`] crate is useful for creating BOLT 11 invoices. Specifically, use the +/// functions in its `utils` module for constructing invoices that are compatible with +/// [`ChannelManager`]. These functions serve as a convenience for building invoices with the +/// [`PaymentHash`] and [`PaymentSecret`] returned from [`create_inbound_payment`]. To provide your +/// own [`PaymentHash`], use [`create_inbound_payment_for_hash`] or the corresponding functions in +/// the [`lightning-invoice`] `utils` module. +/// +/// [`ChannelManager`] generates an [`Event::PaymentClaimable`] once the full payment has been +/// received. Call [`claim_funds`] to release the [`PaymentPreimage`], which in turn will result in +/// an [`Event::PaymentClaimed`]. +/// +/// ``` +/// # use lightning::events::{Event, EventsProvider, PaymentPurpose}; +/// # use lightning::ln::channelmanager::AChannelManager; +/// # +/// # fn example(channel_manager: T) { +/// # let channel_manager = channel_manager.get_cm(); +/// // Or use utils::create_invoice_from_channelmanager +/// let known_payment_hash = match channel_manager.create_inbound_payment( +/// Some(10_000_000), 3600, None +/// ) { +/// Ok((payment_hash, _payment_secret)) => { +/// println!("Creating inbound payment {}", payment_hash); +/// payment_hash +/// }, +/// Err(()) => panic!("Error creating inbound payment"), +/// }; +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentClaimable { payment_hash, purpose, .. } => match purpose { +/// PaymentPurpose::InvoicePayment { payment_preimage: Some(payment_preimage), .. } => { +/// assert_eq!(payment_hash, known_payment_hash); +/// println!("Claiming payment {}", payment_hash); +/// channel_manager.claim_funds(payment_preimage); +/// }, +/// PaymentPurpose::InvoicePayment { payment_preimage: None, .. } => { +/// println!("Unknown payment hash: {}", payment_hash); +/// }, +/// PaymentPurpose::SpontaneousPayment(payment_preimage) => { +/// assert_ne!(payment_hash, known_payment_hash); +/// println!("Claiming spontaneous payment {}", payment_hash); +/// channel_manager.claim_funds(payment_preimage); +/// }, +/// }, +/// Event::PaymentClaimed { payment_hash, amount_msat, .. } => { +/// assert_eq!(payment_hash, known_payment_hash); +/// println!("Claimed {} msats", amount_msat); +/// }, +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// +/// For paying an invoice, [`lightning-invoice`] provides a `payment` module with convenience +/// functions for use with [`send_payment`]. +/// +/// ``` +/// # use lightning::events::{Event, EventsProvider}; +/// # use lightning::ln::PaymentHash; +/// # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, RecipientOnionFields, Retry}; +/// # use lightning::routing::router::RouteParameters; +/// # +/// # fn example( +/// # channel_manager: T, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, +/// # route_params: RouteParameters, retry: Retry +/// # ) { +/// # let channel_manager = channel_manager.get_cm(); +/// // let (payment_hash, recipient_onion, route_params) = +/// // payment::payment_parameters_from_invoice(&invoice); +/// let payment_id = PaymentId([42; 32]); +/// match channel_manager.send_payment( +/// payment_hash, recipient_onion, payment_id, route_params, retry +/// ) { +/// Ok(()) => println!("Sending payment with hash {}", payment_hash), +/// Err(e) => println!("Failed sending payment with hash {}: {:?}", payment_hash, e), +/// } +/// +/// let expected_payment_id = payment_id; +/// let expected_payment_hash = payment_hash; +/// assert!( +/// channel_manager.list_recent_payments().iter().find(|details| matches!( +/// details, +/// RecentPaymentDetails::Pending { +/// payment_id: expected_payment_id, +/// payment_hash: expected_payment_hash, +/// .. +/// } +/// )).is_some() +/// ); +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentSent { payment_hash, .. } => println!("Paid {}", payment_hash), +/// Event::PaymentFailed { payment_hash, .. } => println!("Failed paying {}", payment_hash), +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// +/// ## BOLT 12 Offers +/// +/// The [`offers`] module is useful for creating BOLT 12 offers. An [`Offer`] is a precursor to a +/// [`Bolt12Invoice`], which must first be requested by the payer. The interchange of these messages +/// as defined in the specification is handled by [`ChannelManager`] and its implementation of +/// [`OffersMessageHandler`]. However, this only works with an [`Offer`] created using a builder +/// returned by [`create_offer_builder`]. With this approach, BOLT 12 offers and invoices are +/// stateless just as BOLT 11 invoices are. +/// +/// ``` +/// # use lightning::events::{Event, EventsProvider, PaymentPurpose}; +/// # use lightning::ln::channelmanager::AChannelManager; +/// # use lightning::offers::parse::Bolt12SemanticError; +/// # +/// # fn example(channel_manager: T) -> Result<(), Bolt12SemanticError> { +/// # let channel_manager = channel_manager.get_cm(); +/// let offer = channel_manager +/// .create_offer_builder("coffee".to_string())? +/// # ; +/// # // Needed for compiling for c_bindings +/// # let builder: lightning::offers::offer::OfferBuilder<_, _> = offer.into(); +/// # let offer = builder +/// .amount_msats(10_000_000) +/// .build()?; +/// let bech32_offer = offer.to_string(); +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentClaimable { payment_hash, purpose, .. } => match purpose { +/// PaymentPurpose::InvoicePayment { payment_preimage: Some(payment_preimage), .. } => { +/// println!("Claiming payment {}", payment_hash); +/// channel_manager.claim_funds(payment_preimage); +/// }, +/// PaymentPurpose::InvoicePayment { payment_preimage: None, .. } => { +/// println!("Unknown payment hash: {}", payment_hash); +/// }, +/// // ... +/// # _ => {}, +/// }, +/// Event::PaymentClaimed { payment_hash, amount_msat, .. } => { +/// println!("Claimed {} msats", amount_msat); +/// }, +/// // ... +/// # _ => {}, +/// }); +/// # Ok(()) +/// # } +/// ``` +/// +/// Use [`pay_for_offer`] to initiated payment, which sends an [`InvoiceRequest`] for an [`Offer`] +/// and pays the [`Bolt12Invoice`] response. In addition to success and failure events, +/// [`ChannelManager`] may also generate an [`Event::InvoiceRequestFailed`]. +/// +/// ``` +/// # use lightning::events::{Event, EventsProvider}; +/// # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, Retry}; +/// # use lightning::offers::offer::Offer; +/// # +/// # fn example( +/// # channel_manager: T, offer: &Offer, quantity: Option, amount_msats: Option, +/// # payer_note: Option, retry: Retry, max_total_routing_fee_msat: Option +/// # ) { +/// # let channel_manager = channel_manager.get_cm(); +/// let payment_id = PaymentId([42; 32]); +/// match channel_manager.pay_for_offer( +/// offer, quantity, amount_msats, payer_note, payment_id, retry, max_total_routing_fee_msat +/// ) { +/// Ok(()) => println!("Requesting invoice for offer"), +/// Err(e) => println!("Unable to request invoice for offer: {:?}", e), +/// } +/// +/// // First the payment will be waiting on an invoice +/// let expected_payment_id = payment_id; +/// assert!( +/// channel_manager.list_recent_payments().iter().find(|details| matches!( +/// details, +/// RecentPaymentDetails::AwaitingInvoice { payment_id: expected_payment_id } +/// )).is_some() +/// ); +/// +/// // Once the invoice is received, a payment will be sent +/// assert!( +/// channel_manager.list_recent_payments().iter().find(|details| matches!( +/// details, +/// RecentPaymentDetails::Pending { payment_id: expected_payment_id, .. } +/// )).is_some() +/// ); +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentSent { payment_id: Some(payment_id), .. } => println!("Paid {}", payment_id), +/// Event::PaymentFailed { payment_id, .. } => println!("Failed paying {}", payment_id), +/// Event::InvoiceRequestFailed { payment_id, .. } => println!("Failed paying {}", payment_id), +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// +/// ## BOLT 12 Refunds +/// +/// A [`Refund`] is a request for an invoice to be paid. Like *paying* for an [`Offer`], *creating* +/// a [`Refund`] involves maintaining state since it represents a future outbound payment. +/// Therefore, use [`create_refund_builder`] when creating one, otherwise [`ChannelManager`] will +/// refuse to pay any corresponding [`Bolt12Invoice`] that it receives. +/// +/// ``` +/// # use core::time::Duration; +/// # use lightning::events::{Event, EventsProvider}; +/// # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, Retry}; +/// # use lightning::offers::parse::Bolt12SemanticError; +/// # +/// # fn example( +/// # channel_manager: T, amount_msats: u64, absolute_expiry: Duration, retry: Retry, +/// # max_total_routing_fee_msat: Option +/// # ) -> Result<(), Bolt12SemanticError> { +/// # let channel_manager = channel_manager.get_cm(); +/// let payment_id = PaymentId([42; 32]); +/// let refund = channel_manager +/// .create_refund_builder( +/// "coffee".to_string(), amount_msats, absolute_expiry, payment_id, retry, +/// max_total_routing_fee_msat +/// )? +/// # ; +/// # // Needed for compiling for c_bindings +/// # let builder: lightning::offers::refund::RefundBuilder<_> = refund.into(); +/// # let refund = builder +/// .payer_note("refund for order 1234".to_string()) +/// .build()?; +/// let bech32_refund = refund.to_string(); +/// +/// // First the payment will be waiting on an invoice +/// let expected_payment_id = payment_id; +/// assert!( +/// channel_manager.list_recent_payments().iter().find(|details| matches!( +/// details, +/// RecentPaymentDetails::AwaitingInvoice { payment_id: expected_payment_id } +/// )).is_some() +/// ); +/// +/// // Once the invoice is received, a payment will be sent +/// assert!( +/// channel_manager.list_recent_payments().iter().find(|details| matches!( +/// details, +/// RecentPaymentDetails::Pending { payment_id: expected_payment_id, .. } +/// )).is_some() +/// ); +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentSent { payment_id: Some(payment_id), .. } => println!("Paid {}", payment_id), +/// Event::PaymentFailed { payment_id, .. } => println!("Failed paying {}", payment_id), +/// // ... +/// # _ => {}, +/// }); +/// # Ok(()) +/// # } +/// ``` +/// +/// Use [`request_refund_payment`] to send a [`Bolt12Invoice`] for receiving the refund. Similar to +/// *creating* an [`Offer`], this is stateless as it represents an inbound payment. +/// +/// ``` +/// # use lightning::events::{Event, EventsProvider, PaymentPurpose}; +/// # use lightning::ln::channelmanager::AChannelManager; +/// # use lightning::offers::refund::Refund; +/// # +/// # fn example(channel_manager: T, refund: &Refund) { +/// # let channel_manager = channel_manager.get_cm(); +/// match channel_manager.request_refund_payment(refund) { +/// Ok(()) => println!("Requesting payment for refund"), +/// Err(e) => println!("Unable to request payment for refund: {:?}", e), +/// } +/// +/// // On the event processing thread +/// channel_manager.process_pending_events(&|event| match event { +/// Event::PaymentClaimable { payment_hash, purpose, .. } => match purpose { +/// PaymentPurpose::InvoicePayment { payment_preimage: Some(payment_preimage), .. } => { +/// println!("Claiming payment {}", payment_hash); +/// channel_manager.claim_funds(payment_preimage); +/// }, +/// PaymentPurpose::InvoicePayment { payment_preimage: None, .. } => { +/// println!("Unknown payment hash: {}", payment_hash); +/// }, +/// // ... +/// # _ => {}, +/// }, +/// Event::PaymentClaimed { payment_hash, amount_msat, .. } => { +/// println!("Claimed {} msats", amount_msat); +/// }, +/// // ... +/// # _ => {}, +/// }); +/// # } +/// ``` +/// +/// # Persistence /// /// Implements [`Writeable`] to write out all channel state to disk. Implies [`peer_disconnected`] for /// all peers during write/read (though does not modify this instance, only the instance being @@ -1134,12 +1743,16 @@ where /// tells you the last block hash which was connected. You should get the best block tip before using the manager. /// See [`chain::Listen`] and [`chain::Confirm`] for more details. /// +/// # `ChannelUpdate` Messages +/// /// Note that `ChannelManager` is responsible for tracking liveness of its channels and generating /// [`ChannelUpdate`] messages informing peers that the channel is temporarily disabled. To avoid /// spam due to quick disconnection/reconnection, updates are not sent until the channel has been /// offline for a full minute. In order to track this, you must call /// [`timer_tick_occurred`] roughly once per minute, though it doesn't have to be perfect. /// +/// # DoS Mitigation +/// /// To avoid trivial DoS issues, `ChannelManager` limits the number of inbound connections and /// inbound channels without confirmed funding transactions. This may result in nodes which we do /// not have a channel with being unable to connect to us or open new channels with us if we have @@ -1149,19 +1762,53 @@ where /// exempted from the count of unfunded channels. Similarly, outbound channels and connections are /// never limited. Please ensure you limit the count of such channels yourself. /// +/// # Type Aliases +/// /// Rather than using a plain `ChannelManager`, it is preferable to use either a [`SimpleArcChannelManager`] /// a [`SimpleRefChannelManager`], for conciseness. See their documentation for more details, but /// essentially you should default to using a [`SimpleRefChannelManager`], and use a /// [`SimpleArcChannelManager`] when you require a `ChannelManager` with a static lifetime, such as when /// you're using lightning-net-tokio. /// +/// [`ChainMonitor`]: crate::chain::chainmonitor::ChainMonitor +/// [`MessageHandler`]: crate::ln::peer_handler::MessageHandler +/// [`OnionMessenger`]: crate::onion_message::messenger::OnionMessenger +/// [`PeerManager::read_event`]: crate::ln::peer_handler::PeerManager::read_event +/// [`PeerManager::process_events`]: crate::ln::peer_handler::PeerManager::process_events +/// [`timer_tick_occurred`]: Self::timer_tick_occurred +/// [`get_and_clear_needs_persistence`]: Self::get_and_clear_needs_persistence +/// [`Persister`]: crate::util::persist::Persister +/// [`KVStore`]: crate::util::persist::KVStore +/// [`get_event_or_persistence_needed_future`]: Self::get_event_or_persistence_needed_future +/// [`lightning-block-sync`]: https://docs.rs/lightning_block_sync/latest/lightning_block_sync +/// [`lightning-transaction-sync`]: https://docs.rs/lightning_transaction_sync/latest/lightning_transaction_sync +/// [`lightning-background-processor`]: https://docs.rs/lightning_background_processor/lightning_background_processor +/// [`list_channels`]: Self::list_channels +/// [`list_usable_channels`]: Self::list_usable_channels +/// [`create_channel`]: Self::create_channel +/// [`close_channel`]: Self::force_close_broadcasting_latest_txn +/// [`force_close_broadcasting_latest_txn`]: Self::force_close_broadcasting_latest_txn +/// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md +/// [BOLT 12]: https://github.com/rustyrussell/lightning-rfc/blob/guilt/offers/12-offer-encoding.md +/// [`list_recent_payments`]: Self::list_recent_payments +/// [`abandon_payment`]: Self::abandon_payment +/// [`lightning-invoice`]: https://docs.rs/lightning_invoice/latest/lightning_invoice +/// [`create_inbound_payment`]: Self::create_inbound_payment +/// [`create_inbound_payment_for_hash`]: Self::create_inbound_payment_for_hash +/// [`claim_funds`]: Self::claim_funds +/// [`send_payment`]: Self::send_payment +/// [`offers`]: crate::offers +/// [`create_offer_builder`]: Self::create_offer_builder +/// [`pay_for_offer`]: Self::pay_for_offer +/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest +/// [`create_refund_builder`]: Self::create_refund_builder +/// [`request_refund_payment`]: Self::request_refund_payment /// [`peer_disconnected`]: msgs::ChannelMessageHandler::peer_disconnected /// [`funding_created`]: msgs::FundingCreated /// [`funding_transaction_generated`]: Self::funding_transaction_generated /// [`BlockHash`]: bitcoin::hash_types::BlockHash /// [`update_channel`]: chain::Watch::update_channel /// [`ChannelUpdate`]: msgs::ChannelUpdate -/// [`timer_tick_occurred`]: Self::timer_tick_occurred /// [`read`]: ReadableArgs::read // // Lock order: @@ -1428,6 +2075,9 @@ where pending_offers_messages: Mutex>>, + /// Tracks the message events that are to be broadcasted when we are connected to some peer. + pending_broadcast_messages: Mutex>, + entropy_source: ES, node_signer: NS, signer_provider: SP, @@ -2019,7 +2669,7 @@ macro_rules! handle_error { match $internal { Ok(msg) => Ok(msg), Err(MsgHandleErrInternal { err, shutdown_finish, .. }) => { - let mut msg_events = Vec::with_capacity(2); + let mut msg_event = None; if let Some((shutdown_res, update_option)) = shutdown_finish { let counterparty_node_id = shutdown_res.counterparty_node_id; @@ -2031,7 +2681,8 @@ macro_rules! handle_error { $self.finish_close_channel(shutdown_res); if let Some(update) = update_option { - msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { + let mut pending_broadcast_messages = $self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg: update }); } @@ -2041,17 +2692,17 @@ macro_rules! handle_error { if let msgs::ErrorAction::IgnoreError = err.action { } else { - msg_events.push(events::MessageSendEvent::HandleError { + msg_event = Some(events::MessageSendEvent::HandleError { node_id: $counterparty_node_id, action: err.action.clone() }); } - if !msg_events.is_empty() { + if let Some(msg_event) = msg_event { let per_peer_state = $self.per_peer_state.read().unwrap(); if let Some(peer_state_mutex) = per_peer_state.get(&$counterparty_node_id) { let mut peer_state = peer_state_mutex.lock().unwrap(); - peer_state.pending_msg_events.append(&mut msg_events); + peer_state.pending_msg_events.push(msg_event); } } @@ -2522,6 +3173,7 @@ where funding_batch_states: Mutex::new(BTreeMap::new()), pending_offers_messages: Mutex::new(Vec::new()), + pending_broadcast_messages: Mutex::new(Vec::new()), entropy_source, node_signer, @@ -3020,17 +3672,11 @@ where } }; if let Some(update) = update_opt { - // Try to send the `BroadcastChannelUpdate` to the peer we just force-closed on, but if - // not try to broadcast it via whatever peer we have. - let per_peer_state = self.per_peer_state.read().unwrap(); - let a_peer_state_opt = per_peer_state.get(peer_node_id) - .ok_or(per_peer_state.values().next()); - if let Ok(a_peer_state_mutex) = a_peer_state_opt { - let mut a_peer_state = a_peer_state_mutex.lock().unwrap(); - a_peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { - msg: update - }); - } + // If we have some Channel Update to broadcast, we cache it and broadcast it later. + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { + msg: update + }); } Ok(counterparty_node_id) @@ -4113,6 +4759,7 @@ where .ok_or_else(|| APIError::ChannelUnavailable { err: format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id) })?; let mut peer_state_lock = peer_state_mutex.lock().unwrap(); let peer_state = &mut *peer_state_lock; + for channel_id in channel_ids { if !peer_state.has_channel(channel_id) { return Err(APIError::ChannelUnavailable { @@ -4129,7 +4776,8 @@ where } if let ChannelPhase::Funded(channel) = channel_phase { if let Ok(msg) = self.get_channel_update_for_broadcast(channel) { - peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { msg }); + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg }); } else if let Ok(msg) = self.get_channel_update_for_unicast(channel) { peer_state.pending_msg_events.push(events::MessageSendEvent::SendChannelUpdate { node_id: channel.context.get_counterparty_node_id(), @@ -4304,6 +4952,145 @@ where Ok(()) } + fn process_pending_update_add_htlcs(&self) { + let mut decode_update_add_htlcs = new_hash_map(); + mem::swap(&mut decode_update_add_htlcs, &mut self.decode_update_add_htlcs.lock().unwrap()); + + let get_failed_htlc_destination = |outgoing_scid_opt: Option, payment_hash: PaymentHash| { + if let Some(outgoing_scid) = outgoing_scid_opt { + match self.short_to_chan_info.read().unwrap().get(&outgoing_scid) { + Some((outgoing_counterparty_node_id, outgoing_channel_id)) => + HTLCDestination::NextHopChannel { + node_id: Some(*outgoing_counterparty_node_id), + channel_id: *outgoing_channel_id, + }, + None => HTLCDestination::UnknownNextHop { + requested_forward_scid: outgoing_scid, + }, + } + } else { + HTLCDestination::FailedPayment { payment_hash } + } + }; + + 'outer_loop: for (incoming_scid, update_add_htlcs) in decode_update_add_htlcs { + let incoming_channel_details_opt = self.do_funded_channel_callback(incoming_scid, |chan: &mut Channel| { + let counterparty_node_id = chan.context.get_counterparty_node_id(); + let channel_id = chan.context.channel_id(); + let funding_txo = chan.context.get_funding_txo().unwrap(); + let user_channel_id = chan.context.get_user_id(); + let accept_underpaying_htlcs = chan.context.config().accept_underpaying_htlcs; + (counterparty_node_id, channel_id, funding_txo, user_channel_id, accept_underpaying_htlcs) + }); + let ( + incoming_counterparty_node_id, incoming_channel_id, incoming_funding_txo, + incoming_user_channel_id, incoming_accept_underpaying_htlcs + ) = if let Some(incoming_channel_details) = incoming_channel_details_opt { + incoming_channel_details + } else { + // The incoming channel no longer exists, HTLCs should be resolved onchain instead. + continue; + }; + + let mut htlc_forwards = Vec::new(); + let mut htlc_fails = Vec::new(); + for update_add_htlc in &update_add_htlcs { + let (next_hop, shared_secret, next_packet_details_opt) = match decode_incoming_update_add_htlc_onion( + &update_add_htlc, &self.node_signer, &self.logger, &self.secp_ctx + ) { + Ok(decoded_onion) => decoded_onion, + Err(htlc_fail) => { + htlc_fails.push((htlc_fail, HTLCDestination::InvalidOnion)); + continue; + }, + }; + + let is_intro_node_blinded_forward = next_hop.is_intro_node_blinded_forward(); + let outgoing_scid_opt = next_packet_details_opt.as_ref().map(|d| d.outgoing_scid); + + // Process the HTLC on the incoming channel. + match self.do_funded_channel_callback(incoming_scid, |chan: &mut Channel| { + let logger = WithChannelContext::from(&self.logger, &chan.context); + chan.can_accept_incoming_htlc( + update_add_htlc, &self.fee_estimator, &logger, + ) + }) { + Some(Ok(_)) => {}, + Some(Err((err, code))) => { + let outgoing_chan_update_opt = if let Some(outgoing_scid) = outgoing_scid_opt.as_ref() { + self.do_funded_channel_callback(*outgoing_scid, |chan: &mut Channel| { + self.get_channel_update_for_onion(*outgoing_scid, chan).ok() + }).flatten() + } else { + None + }; + let htlc_fail = self.htlc_failure_from_update_add_err( + &update_add_htlc, &incoming_counterparty_node_id, err, code, + outgoing_chan_update_opt, is_intro_node_blinded_forward, &shared_secret, + ); + let htlc_destination = get_failed_htlc_destination(outgoing_scid_opt, update_add_htlc.payment_hash); + htlc_fails.push((htlc_fail, htlc_destination)); + continue; + }, + // The incoming channel no longer exists, HTLCs should be resolved onchain instead. + None => continue 'outer_loop, + } + + // Now process the HTLC on the outgoing channel if it's a forward. + if let Some(next_packet_details) = next_packet_details_opt.as_ref() { + if let Err((err, code, chan_update_opt)) = self.can_forward_htlc( + &update_add_htlc, next_packet_details + ) { + let htlc_fail = self.htlc_failure_from_update_add_err( + &update_add_htlc, &incoming_counterparty_node_id, err, code, + chan_update_opt, is_intro_node_blinded_forward, &shared_secret, + ); + let htlc_destination = get_failed_htlc_destination(outgoing_scid_opt, update_add_htlc.payment_hash); + htlc_fails.push((htlc_fail, htlc_destination)); + continue; + } + } + + match self.construct_pending_htlc_status( + &update_add_htlc, &incoming_counterparty_node_id, shared_secret, next_hop, + incoming_accept_underpaying_htlcs, next_packet_details_opt.map(|d| d.next_packet_pubkey), + ) { + PendingHTLCStatus::Forward(htlc_forward) => { + htlc_forwards.push((htlc_forward, update_add_htlc.htlc_id)); + }, + PendingHTLCStatus::Fail(htlc_fail) => { + let htlc_destination = get_failed_htlc_destination(outgoing_scid_opt, update_add_htlc.payment_hash); + htlc_fails.push((htlc_fail, htlc_destination)); + }, + } + } + + // Process all of the forwards and failures for the channel in which the HTLCs were + // proposed to as a batch. + let pending_forwards = (incoming_scid, incoming_funding_txo, incoming_channel_id, + incoming_user_channel_id, htlc_forwards.drain(..).collect()); + self.forward_htlcs_without_forward_event(&mut [pending_forwards]); + for (htlc_fail, htlc_destination) in htlc_fails.drain(..) { + let failure = match htlc_fail { + HTLCFailureMsg::Relay(fail_htlc) => HTLCForwardInfo::FailHTLC { + htlc_id: fail_htlc.htlc_id, + err_packet: fail_htlc.reason, + }, + HTLCFailureMsg::Malformed(fail_malformed_htlc) => HTLCForwardInfo::FailMalformedHTLC { + htlc_id: fail_malformed_htlc.htlc_id, + sha256_of_onion: fail_malformed_htlc.sha256_of_onion, + failure_code: fail_malformed_htlc.failure_code, + }, + }; + self.forward_htlcs.lock().unwrap().entry(incoming_scid).or_insert(vec![]).push(failure); + self.pending_events.lock().unwrap().push_back((events::Event::HTLCHandlingFailed { + prev_channel_id: incoming_channel_id, + failed_next_destination: htlc_destination, + }, None)); + } + } + } + /// Processes HTLCs which are pending waiting on random forward delay. /// /// Should only really ever be called in response to a PendingHTLCsForwardable event. @@ -4311,6 +5098,8 @@ where pub fn process_pending_htlc_forwards(&self) { let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self); + self.process_pending_update_add_htlcs(); + let mut new_events = VecDeque::new(); let mut failed_forwards = Vec::new(); let mut phantom_receives: Vec<(u64, OutPoint, ChannelId, u128, Vec<(PendingHTLCInfo, u64)>)> = Vec::new(); @@ -5038,7 +5827,8 @@ where if n >= DISABLE_GOSSIP_TICKS { chan.set_channel_update_status(ChannelUpdateStatus::Disabled); if let Ok(update) = self.get_channel_update_for_broadcast(&chan) { - pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg: update }); } @@ -5052,7 +5842,8 @@ where if n >= ENABLE_GOSSIP_TICKS { chan.set_channel_update_status(ChannelUpdateStatus::Enabled); if let Ok(update) = self.get_channel_update_for_broadcast(&chan) { - pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg: update }); } @@ -5355,9 +6146,14 @@ where } } + fn fail_htlc_backwards_internal(&self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason, destination: HTLCDestination) { + let push_forward_event = self.fail_htlc_backwards_internal_without_forward_event(source, payment_hash, onion_error, destination); + if push_forward_event { self.push_pending_forwards_ev(); } + } + /// Fails an HTLC backwards to the sender of it to us. /// Note that we do not assume that channels corresponding to failed HTLCs are still available. - fn fail_htlc_backwards_internal(&self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason, destination: HTLCDestination) { + fn fail_htlc_backwards_internal_without_forward_event(&self, source: &HTLCSource, payment_hash: &PaymentHash, onion_error: &HTLCFailReason, destination: HTLCDestination) -> bool { // Ensure that no peer state channel storage lock is held when calling this function. // This ensures that future code doesn't introduce a lock-order requirement for // `forward_htlcs` to be locked after the `per_peer_state` peer locks, which calling @@ -5375,12 +6171,12 @@ where // Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called // from block_connected which may run during initialization prior to the chain_monitor // being fully configured. See the docs for `ChannelManagerReadArgs` for more. + let mut push_forward_event; match source { HTLCSource::OutboundRoute { ref path, ref session_priv, ref payment_id, .. } => { - if self.pending_outbound_payments.fail_htlc(source, payment_hash, onion_error, path, + push_forward_event = self.pending_outbound_payments.fail_htlc(source, payment_hash, onion_error, path, session_priv, payment_id, self.probing_cookie_secret, &self.secp_ctx, - &self.pending_events, &self.logger) - { self.push_pending_forwards_ev(); } + &self.pending_events, &self.logger); }, HTLCSource::PreviousHopData(HTLCPreviousHopData { ref short_channel_id, ref htlc_id, ref incoming_packet_shared_secret, @@ -5414,11 +6210,9 @@ where } }; - let mut push_forward_ev = false; + push_forward_event = self.decode_update_add_htlcs.lock().unwrap().is_empty(); let mut forward_htlcs = self.forward_htlcs.lock().unwrap(); - if forward_htlcs.is_empty() { - push_forward_ev = true; - } + push_forward_event &= forward_htlcs.is_empty(); match forward_htlcs.entry(*short_channel_id) { hash_map::Entry::Occupied(mut entry) => { entry.get_mut().push(failure); @@ -5428,7 +6222,6 @@ where } } mem::drop(forward_htlcs); - if push_forward_ev { self.push_pending_forwards_ev(); } let mut pending_events = self.pending_events.lock().unwrap(); pending_events.push_back((events::Event::HTLCHandlingFailed { prev_channel_id: *channel_id, @@ -5436,6 +6229,7 @@ where }, None)); }, } + push_forward_event } /// Provides a payment preimage in response to [`Event::PaymentClaimable`], generating any @@ -6775,9 +7569,8 @@ where } if let Some(ChannelPhase::Funded(chan)) = chan_option { if let Ok(update) = self.get_channel_update_for_broadcast(&chan) { - let mut peer_state_lock = peer_state_mutex.lock().unwrap(); - let peer_state = &mut *peer_state_lock; - peer_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg: update }); } @@ -7005,18 +7798,27 @@ where } fn push_decode_update_add_htlcs(&self, mut update_add_htlcs: (u64, Vec)) { + let mut push_forward_event = self.forward_htlcs.lock().unwrap().is_empty(); let mut decode_update_add_htlcs = self.decode_update_add_htlcs.lock().unwrap(); + push_forward_event &= decode_update_add_htlcs.is_empty(); let scid = update_add_htlcs.0; match decode_update_add_htlcs.entry(scid) { hash_map::Entry::Occupied(mut e) => { e.get_mut().append(&mut update_add_htlcs.1); }, hash_map::Entry::Vacant(e) => { e.insert(update_add_htlcs.1); }, } + if push_forward_event { self.push_pending_forwards_ev(); } } #[inline] fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, OutPoint, ChannelId, u128, Vec<(PendingHTLCInfo, u64)>)]) { + let push_forward_event = self.forward_htlcs_without_forward_event(per_source_pending_forwards); + if push_forward_event { self.push_pending_forwards_ev() } + } + + #[inline] + fn forward_htlcs_without_forward_event(&self, per_source_pending_forwards: &mut [(u64, OutPoint, ChannelId, u128, Vec<(PendingHTLCInfo, u64)>)]) -> bool { + let mut push_forward_event = false; for &mut (prev_short_channel_id, prev_funding_outpoint, prev_channel_id, prev_user_channel_id, ref mut pending_forwards) in per_source_pending_forwards { - let mut push_forward_event = false; let mut new_intercept_events = VecDeque::new(); let mut failed_intercept_forwards = Vec::new(); if !pending_forwards.is_empty() { @@ -7029,6 +7831,7 @@ where // Pull this now to avoid introducing a lock order with `forward_htlcs`. let is_our_scid = self.short_to_chan_info.read().unwrap().contains_key(&scid); + let decode_update_add_htlcs_empty = self.decode_update_add_htlcs.lock().unwrap().is_empty(); let mut forward_htlcs = self.forward_htlcs.lock().unwrap(); let forward_htlcs_empty = forward_htlcs.is_empty(); match forward_htlcs.entry(scid) { @@ -7077,9 +7880,7 @@ where } else { // We don't want to generate a PendingHTLCsForwardable event if only intercepted // payments are being processed. - if forward_htlcs_empty { - push_forward_event = true; - } + push_forward_event |= forward_htlcs_empty && decode_update_add_htlcs_empty; entry.insert(vec!(HTLCForwardInfo::AddHTLC(PendingAddHTLCInfo { prev_short_channel_id, prev_funding_outpoint, prev_channel_id, prev_htlc_id, prev_user_channel_id, forward_info }))); } @@ -7089,15 +7890,15 @@ where } for (htlc_source, payment_hash, failure_reason, destination) in failed_intercept_forwards.drain(..) { - self.fail_htlc_backwards_internal(&htlc_source, &payment_hash, &failure_reason, destination); + push_forward_event |= self.fail_htlc_backwards_internal_without_forward_event(&htlc_source, &payment_hash, &failure_reason, destination); } if !new_intercept_events.is_empty() { let mut events = self.pending_events.lock().unwrap(); events.append(&mut new_intercept_events); } - if push_forward_event { self.push_pending_forwards_ev() } } + push_forward_event } fn push_pending_forwards_ev(&self) { @@ -7454,7 +8255,8 @@ where }; failed_channels.push(chan.context.force_shutdown(false, reason.clone())); if let Ok(update) = self.get_channel_update_for_broadcast(&chan) { - pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg: update }); } @@ -7639,7 +8441,8 @@ where // We're done with this channel. We got a closing_signed and sent back // a closing_signed with a closing transaction to broadcast. if let Ok(update) = self.get_channel_update_for_broadcast(&chan) { - pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg: update }); } @@ -8399,7 +9202,7 @@ where /// will randomly be placed first or last in the returned array. /// /// Note that even though `BroadcastChannelAnnouncement` and `BroadcastChannelUpdate` - /// `MessageSendEvent`s are intended to be broadcasted to all peers, they will be pleaced among + /// `MessageSendEvent`s are intended to be broadcasted to all peers, they will be placed among /// the `MessageSendEvent`s to the specific peer they were generated under. fn get_and_clear_pending_msg_events(&self) -> Vec { let events = RefCell::new(Vec::new()); @@ -8419,6 +9222,7 @@ where result = NotifyOption::DoPersist; } + let mut is_any_peer_connected = false; let mut pending_events = Vec::new(); let per_peer_state = self.per_peer_state.read().unwrap(); for (_cp_id, peer_state_mutex) in per_peer_state.iter() { @@ -8427,6 +9231,15 @@ where if peer_state.pending_msg_events.len() > 0 { pending_events.append(&mut peer_state.pending_msg_events); } + if peer_state.is_connected { + is_any_peer_connected = true + } + } + + // Ensure that we are connected to some peers before getting broadcast messages. + if is_any_peer_connected { + let mut broadcast_msgs = self.pending_broadcast_messages.lock().unwrap(); + pending_events.append(&mut broadcast_msgs); } if !pending_events.is_empty() { @@ -8631,6 +9444,7 @@ where let mut peer_state_lock = peer_state_mutex.lock().unwrap(); let peer_state = &mut *peer_state_lock; let pending_msg_events = &mut peer_state.pending_msg_events; + peer_state.channel_by_id.retain(|_, phase| { match phase { // Retain unfunded channels. @@ -8706,7 +9520,8 @@ where let reason_message = format!("{}", reason); failed_channels.push(channel.context.force_shutdown(true, reason)); if let Ok(update) = self.get_channel_update_for_broadcast(&channel) { - pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate { + let mut pending_broadcast_messages = self.pending_broadcast_messages.lock().unwrap(); + pending_broadcast_messages.push(events::MessageSendEvent::BroadcastChannelUpdate { msg: update }); } @@ -8798,6 +9613,9 @@ where } /// Returns true if this [`ChannelManager`] needs to be persisted. + /// + /// See [`Self::get_event_or_persistence_needed_future`] for retrieving a [`Future`] that + /// indicates this should be checked. pub fn get_and_clear_needs_persistence(&self) -> bool { self.needs_persist_flag.swap(false, Ordering::AcqRel) } @@ -9163,7 +9981,12 @@ where // Gossip &events::MessageSendEvent::SendChannelAnnouncement { .. } => false, &events::MessageSendEvent::BroadcastChannelAnnouncement { .. } => true, - &events::MessageSendEvent::BroadcastChannelUpdate { .. } => true, + // [`ChannelManager::pending_broadcast_events`] holds the [`BroadcastChannelUpdate`] + // This check here is to ensure exhaustivity. + &events::MessageSendEvent::BroadcastChannelUpdate { .. } => { + debug_assert!(false, "This event shouldn't have been here"); + false + }, &events::MessageSendEvent::BroadcastNodeAnnouncement { .. } => true, &events::MessageSendEvent::SendChannelUpdate { .. } => false, &events::MessageSendEvent::SendChannelRangeQuery { .. } => false, @@ -10874,7 +11697,7 @@ where (13, claimable_htlc_onion_fields, optional_vec), (14, decode_update_add_htlcs, option), }); - let decode_update_add_htlcs = decode_update_add_htlcs.unwrap_or_else(|| new_hash_map()); + let mut decode_update_add_htlcs = decode_update_add_htlcs.unwrap_or_else(|| new_hash_map()); if fake_scid_rand_bytes.is_none() { fake_scid_rand_bytes = Some(args.entropy_source.get_secure_random_bytes()); } @@ -10974,7 +11797,7 @@ where } } if chan.get_latest_unblocked_monitor_update_id() > max_in_flight_update_id { - // If the channel is ahead of the monitor, return InvalidValue: + // If the channel is ahead of the monitor, return DangerousValue: log_error!(logger, "A ChannelMonitor is stale compared to the current ChannelManager! This indicates a potentially-critical violation of the chain::Watch API!"); log_error!(logger, " The ChannelMonitor for channel {} is at update_id {} with update_id through {} in-flight", chan.context.channel_id(), monitor.get_latest_update_id(), max_in_flight_update_id); @@ -10983,7 +11806,7 @@ where log_error!(logger, " client applications must ensure that ChannelMonitor data is always available and the latest to avoid funds loss!"); log_error!(logger, " Without the latest ChannelMonitor we cannot continue without risking funds."); log_error!(logger, " Please ensure the chain::Watch API requirements are met and file a bug report at https://github.com/lightningdevkit/rust-lightning"); - return Err(DecodeError::InvalidValue); + return Err(DecodeError::DangerousValue); } } else { // We shouldn't have persisted (or read) any unfunded channel types so none should have been @@ -11094,6 +11917,18 @@ where // still have an entry for this HTLC in `forward_htlcs` or // `pending_intercepted_htlcs`, we were apparently not persisted after // the monitor was when forwarding the payment. + decode_update_add_htlcs.retain(|scid, update_add_htlcs| { + update_add_htlcs.retain(|update_add_htlc| { + let matches = *scid == prev_hop_data.short_channel_id && + update_add_htlc.htlc_id == prev_hop_data.htlc_id; + if matches { + log_info!(logger, "Removing pending to-decode HTLC with hash {} as it was forwarded to the closed channel {}", + &htlc.payment_hash, &monitor.channel_id()); + } + !matches + }); + !update_add_htlcs.is_empty() + }); forward_htlcs.retain(|_, forwards| { forwards.retain(|forward| { if let HTLCForwardInfo::AddHTLC(htlc_info) = forward { @@ -11175,7 +12010,7 @@ where } } - if !forward_htlcs.is_empty() || pending_outbounds.needs_abandon() { + if !forward_htlcs.is_empty() || !decode_update_add_htlcs.is_empty() || pending_outbounds.needs_abandon() { // If we have pending HTLCs to forward, assume we either dropped a // `PendingHTLCsForwardable` or the user received it but never processed it as they // shut down before the timer hit. Either way, set the time_forwardable to a small @@ -11438,6 +12273,8 @@ where pending_offers_messages: Mutex::new(Vec::new()), + pending_broadcast_messages: Mutex::new(Vec::new()), + entropy_source: args.entropy_source, node_signer: args.node_signer, signer_provider: args.signer_provider, @@ -11969,6 +12806,61 @@ mod tests { } } + #[test] + fn test_channel_update_cached() { + let chanmon_cfgs = create_chanmon_cfgs(3); + let node_cfgs = create_node_cfgs(3, &chanmon_cfgs); + let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]); + let nodes = create_network(3, &node_cfgs, &node_chanmgrs); + + let chan = create_announced_chan_between_nodes(&nodes, 0, 1); + + nodes[0].node.force_close_channel_with_peer(&chan.2, &nodes[1].node.get_our_node_id(), None, true).unwrap(); + check_added_monitors!(nodes[0], 1); + check_closed_event!(nodes[0], 1, ClosureReason::HolderForceClosed, [nodes[1].node.get_our_node_id()], 100000); + + // Confirm that the channel_update was not sent immediately to node[1] but was cached. + let node_1_events = nodes[1].node.get_and_clear_pending_msg_events(); + assert_eq!(node_1_events.len(), 0); + + { + // Assert that ChannelUpdate message has been added to node[0] pending broadcast messages + let pending_broadcast_messages= nodes[0].node.pending_broadcast_messages.lock().unwrap(); + assert_eq!(pending_broadcast_messages.len(), 1); + } + + // Test that we do not retrieve the pending broadcast messages when we are not connected to any peer + nodes[0].node.peer_disconnected(&nodes[1].node.get_our_node_id()); + nodes[1].node.peer_disconnected(&nodes[0].node.get_our_node_id()); + + nodes[0].node.peer_disconnected(&nodes[2].node.get_our_node_id()); + nodes[2].node.peer_disconnected(&nodes[0].node.get_our_node_id()); + + let node_0_events = nodes[0].node.get_and_clear_pending_msg_events(); + assert_eq!(node_0_events.len(), 0); + + // Now we reconnect to a peer + nodes[0].node.peer_connected(&nodes[2].node.get_our_node_id(), &msgs::Init { + features: nodes[2].node.init_features(), networks: None, remote_network_address: None + }, true).unwrap(); + nodes[2].node.peer_connected(&nodes[0].node.get_our_node_id(), &msgs::Init { + features: nodes[0].node.init_features(), networks: None, remote_network_address: None + }, false).unwrap(); + + // Confirm that get_and_clear_pending_msg_events correctly captures pending broadcast messages + let node_0_events = nodes[0].node.get_and_clear_pending_msg_events(); + assert_eq!(node_0_events.len(), 1); + match &node_0_events[0] { + MessageSendEvent::BroadcastChannelUpdate { .. } => (), + _ => panic!("Unexpected event"), + } + { + // Assert that ChannelUpdate message has been cleared from nodes[0] pending broadcast messages + let pending_broadcast_messages= nodes[0].node.pending_broadcast_messages.lock().unwrap(); + assert_eq!(pending_broadcast_messages.len(), 0); + } + } + #[test] fn test_drop_disconnected_peers_when_removing_channels() { let chanmon_cfgs = create_chanmon_cfgs(2);