//! 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. use ln::msgs; use ln::channelmanager::{PaymentPreimage, PaymentHash}; use chain::transaction::OutPoint; use chain::keysinterface::SpendableOutputDescriptor; use util::ser::{Writeable, Writer, MaybeReadable, Readable}; use bitcoin::blockdata::script::Script; use secp256k1::key::PublicKey; use std::time::Duration; /// 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). 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. /// Generated in ChannelManager message handling. /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your /// counterparty can steal your funds! FundingGenerationReady { /// The random channel_id we picked which you'll need to pass into /// ChannelManager::funding_transaction_generated. temporary_channel_id: [u8; 32], /// The value, in satoshis, that the output should have. channel_value_satoshis: u64, /// The script which should be used in the transaction output. output_script: Script, /// 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. /// The amount paid should be considered 'incorrect' when it is less than or more than twice /// the amount expected. PaymentReceived { /// The hash for which the preimage should be handed to the ChannelManager. payment_hash: PaymentHash, /// 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, }, /// 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 /// store it somehow! payment_preimage: PaymentPreimage, }, /// 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, /// Indicates the payment was rejected for some reason by the recipient. This implies that /// the payment has failed, not just the route in question. If this is not set, you may /// retry the payment via a different route. rejected_by_dest: bool, #[cfg(test)] error_code: Option, }, /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a /// time in the future. PendingHTLCsForwardable { /// The minimum amount of time that should be waited prior to calling /// process_pending_htlc_forwards. To increase the effort required to correlate payments, /// you should wait a random amount of time in roughly the range (now + time_forwardable, /// now + 5*time_forwardable). time_forwardable: Duration, }, /// Used to indicate that an output was generated on-chain which you should know how to spend. /// 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. SpendableOutputs { /// The outputs which you should store as spendable by you. outputs: Vec, }, } 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::FundingBroadcastSafe { ref funding_txo, ref user_channel_id } => { 1u8.write(writer)?; funding_txo.write(writer)?; user_channel_id.write(writer)?; }, &Event::PaymentReceived { ref payment_hash, ref amt } => { 2u8.write(writer)?; payment_hash.write(writer)?; amt.write(writer)?; }, &Event::PaymentSent { ref payment_preimage } => { 3u8.write(writer)?; payment_preimage.write(writer)?; }, &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest, #[cfg(test)] ref error_code, } => { 4u8.write(writer)?; payment_hash.write(writer)?; rejected_by_dest.write(writer)?; #[cfg(test)] error_code.write(writer)?; }, &Event::PendingHTLCsForwardable { time_forwardable: _ } => { 5u8.write(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 } => { 6u8.write(writer)?; (outputs.len() as u64).write(writer)?; for output in outputs.iter() { output.write(writer)?; } }, } Ok(()) } } impl MaybeReadable for Event { fn read(reader: &mut R) -> Result, msgs::DecodeError> { match Readable::read(reader)? { 0u8 => Ok(None), 1u8 => Ok(Some(Event::FundingBroadcastSafe { funding_txo: Readable::read(reader)?, user_channel_id: Readable::read(reader)?, })), 2u8 => Ok(Some(Event::PaymentReceived { payment_hash: Readable::read(reader)?, amt: Readable::read(reader)?, })), 3u8 => Ok(Some(Event::PaymentSent { payment_preimage: Readable::read(reader)?, })), 4u8 => Ok(Some(Event::PaymentFailed { payment_hash: Readable::read(reader)?, rejected_by_dest: Readable::read(reader)?, #[cfg(test)] error_code: Readable::read(reader)?, })), 5u8 => Ok(Some(Event::PendingHTLCsForwardable { time_forwardable: Duration::from_secs(0) })), 6u8 => { 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 })) }, _ => 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)] 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. SendAcceptChannel { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::AcceptChannel, }, /// Used to indicate that we've initiated a channel open and should send the open_channel /// message provided to the given peer. SendOpenChannel { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::OpenChannel, }, /// Used to indicate that a funding_created message should be sent to the peer with the given node_id. SendFundingCreated { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::FundingCreated, }, /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id. SendFundingSigned { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::FundingSigned, }, /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id. SendFundingLocked { /// The node_id of the node which should receive these message(s) node_id: PublicKey, /// The funding_locked message which should be sent. msg: msgs::FundingLocked, }, /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id. SendAnnouncementSignatures { /// The node_id of the node which should receive these message(s) node_id: PublicKey, /// The announcement_signatures message which should be sent. msg: msgs::AnnouncementSignatures, }, /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed /// message should be sent to the peer with the given node_id. UpdateHTLCs { /// The node_id of the node which should receive these message(s) node_id: PublicKey, /// The update messages which should be sent. ALL messages in the struct should be sent! updates: msgs::CommitmentUpdate, }, /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id. SendRevokeAndACK { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::RevokeAndACK, }, /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id. SendClosingSigned { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::ClosingSigned, }, /// Used to indicate that a shutdown message should be sent to the peer with the given node_id. SendShutdown { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::Shutdown, }, /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id. SendChannelReestablish { /// The node_id of the node which should receive this message node_id: PublicKey, /// The message which should be sent. msg: msgs::ChannelReestablish, }, /// 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, }, /// Broadcast an error downstream to be handled HandleError { /// The node_id of the node which should receive this message node_id: PublicKey, /// The action which should be taken. 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. PaymentFailureNetworkUpdate { /// The channel/node update which should be sent to router update: msgs::HTLCFailChannelUpdate, } } /// A trait indicating an object may generate message send events pub trait MessageSendEventsProvider { /// Gets the list of pending events which were generated by previous actions, clearing the list /// in the process. fn get_and_clear_pending_msg_events(&self) -> Vec; } /// A trait indicating an object may generate 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; }