X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannel.rs;h=1279f310d4bfdbcfd134a9b53c95674fa0dd21bf;hb=871f4143672b9d8e616dbc2b6df87366590179d0;hp=9e4bb081c1a98ddc5bd17c4b818a835a37f10a65;hpb=b5d88a5422913a0a8950455c5f86764a042429d7;p=rust-lightning diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 9e4bb081..1279f310 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -25,7 +25,7 @@ use bitcoin::secp256k1; use ln::features::{ChannelFeatures, InitFeatures}; use ln::msgs; use ln::msgs::{DecodeError, OptionalField, DataLossProtect}; -use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT}; +use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT}; use ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor}; use ln::chan_utils; use chain::chaininterface::{FeeEstimator,ConfirmationTarget}; @@ -37,6 +37,7 @@ use util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter}; use util::logger::Logger; use util::errors::APIError; use util::config::{UserConfig,ChannelConfig}; +use util::scid_utils::scid_from_parts; use std; use std::{cmp,mem,fmt}; @@ -95,6 +96,7 @@ enum InboundHTLCState { /// is used to derive commitment keys, which are used to construct the /// signatures in a commitment_signed message. /// Implies AwaitingRemoteRevoke. + /// /// [BOLT #2]: https://github.com/lightningnetwork/lightning-rfc/blob/master/02-peer-protocol.md AwaitingRemoteRevokeToAnnounce(PendingHTLCStatus), /// Included in a received commitment_signed message (implying we've revoke_and_ack'd it). @@ -281,6 +283,19 @@ impl HTLCCandidate { } } +/// Information needed for constructing an invoice route hint for this channel. +#[derive(Clone)] +pub struct CounterpartyForwardingInfo { + /// Base routing fee in millisatoshis. + pub fee_base_msat: u32, + /// Amount in millionths of a satoshi the channel will charge per transferred satoshi. + pub fee_proportional_millionths: u32, + /// The minimum difference in cltv_expiry between an ingoing HTLC and its outgoing counterpart, + /// such that the outgoing HTLC is forwardable to this counterparty. See `msgs::ChannelUpdate`'s + /// `cltv_expiry_delta` for more details. + pub cltv_expiry_delta: u16, +} + // TODO: We should refactor this to be an Inbound/OutboundChannel until initial setup handshaking // has been completed, and then turn into a Channel to get compiler-time enforcement of things like // calling channel_id() before we're set up or things like get_outbound_funding_signed on an @@ -361,13 +376,10 @@ pub(super) struct Channel { last_sent_closing_fee: Option<(u32, u64, Signature)>, // (feerate, fee, holder_sig) - /// The hash of the block in which the funding transaction reached our CONF_TARGET. We use this - /// to detect unconfirmation after a serialize-unserialize roundtrip where we may not see a full - /// series of block_connected/block_disconnected calls. Obviously this is not a guarantee as we - /// could miss the funding_tx_confirmed_in block as well, but it serves as a useful fallback. + /// The hash of the block in which the funding transaction was included. funding_tx_confirmed_in: Option, + funding_tx_confirmation_height: u64, short_channel_id: Option, - funding_tx_confirmations: u64, counterparty_dust_limit_satoshis: u64, #[cfg(test)] @@ -391,6 +403,8 @@ pub(super) struct Channel { //implied by OUR_MAX_HTLCS: max_accepted_htlcs: u16, minimum_depth: u32, + counterparty_forwarding_info: Option, + pub(crate) channel_transaction_parameters: ChannelTransactionParameters, counterparty_cur_commitment_point: Option, @@ -424,10 +438,6 @@ struct CommitmentTxInfoCached { } pub const OUR_MAX_HTLCS: u16 = 50; //TODO -/// Confirmation count threshold at which we close a channel. Ideally we'd keep the channel around -/// on ice until the funding transaction gets more confirmations, but the LN protocol doesn't -/// really allow for this, so instead we're stuck closing it out at that point. -const UNCONF_THRESHOLD: u32 = 6; const SPENDING_INPUT_FOR_A_OUTPUT_WEIGHT: u64 = 79; // prevout: 36, nSequence: 4, script len: 1, witness lengths: (3+1)/4, sig: 73/4, if-selector: 1, redeemScript: (6 ops + 2*33 pubkeys + 1*2 delay)/4 const B_OUTPUT_PLUS_SPENDING_INPUT_WEIGHT: u64 = 104; // prevout: 40, nSequence: 4, script len: 1, witness lengths: 3/4, sig: 73/4, pubkey: 33/4, output: 31 (TODO: Wrong? Useless?) @@ -564,8 +574,8 @@ impl Channel { last_sent_closing_fee: None, funding_tx_confirmed_in: None, + funding_tx_confirmation_height: 0, short_channel_id: None, - funding_tx_confirmations: 0, feerate_per_kw: feerate, counterparty_dust_limit_satoshis: 0, @@ -577,6 +587,8 @@ impl Channel { counterparty_max_accepted_htlcs: 0, minimum_depth: 0, // Filled in in accept_channel + counterparty_forwarding_info: None, + channel_transaction_parameters: ChannelTransactionParameters { holder_pubkeys: pubkeys, holder_selected_contest_delay: config.own_channel_config.our_to_self_delay, @@ -799,8 +811,8 @@ impl Channel { last_sent_closing_fee: None, funding_tx_confirmed_in: None, + funding_tx_confirmation_height: 0, short_channel_id: None, - funding_tx_confirmations: 0, feerate_per_kw: msg.feerate_per_kw, channel_value_satoshis: msg.funding_satoshis, @@ -813,6 +825,8 @@ impl Channel { counterparty_max_accepted_htlcs: msg.max_accepted_htlcs, minimum_depth: config.own_channel_config.minimum_depth, + counterparty_forwarding_info: None, + channel_transaction_parameters: ChannelTransactionParameters { holder_pubkeys: pubkeys, holder_selected_contest_delay: config.own_channel_config.our_to_self_delay, @@ -3338,6 +3352,10 @@ impl Channel { self.config.fee_proportional_millionths } + pub fn get_cltv_expiry_delta(&self) -> u16 { + cmp::max(self.config.cltv_expiry_delta, MIN_CLTV_EXPIRY_DELTA) + } + #[cfg(test)] pub fn get_feerate(&self) -> u32 { self.feerate_per_kw @@ -3484,38 +3502,7 @@ impl Channel { self.network_sync == UpdateStatus::DisabledMarked } - /// When we receive a new block, we (a) check whether the block contains the funding - /// transaction (which would start us counting blocks until we send the funding_signed), and - /// (b) check the height of the block against outbound holding cell HTLCs in case we need to - /// give up on them prematurely and time them out. Everything else (e.g. commitment - /// transaction broadcasts, channel closure detection, HTLC transaction broadcasting, etc) is - /// handled by the ChannelMonitor. - /// - /// If we return Err, the channel may have been closed, at which point the standard - /// requirements apply - no calls may be made except those explicitly stated to be allowed - /// post-shutdown. - /// Only returns an ErrorAction of DisconnectPeer, if Err. - /// - /// May return some HTLCs (and their payment_hash) which have timed out and should be failed - /// back. - pub fn block_connected(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32) -> Result<(Option, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage> { - let mut timed_out_htlcs = Vec::new(); - self.holding_cell_htlc_updates.retain(|htlc_update| { - match htlc_update { - &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, ref cltv_expiry, .. } => { - if *cltv_expiry <= height + HTLC_FAIL_BACK_BUFFER { - timed_out_htlcs.push((source.clone(), payment_hash.clone())); - false - } else { true } - }, - _ => true - } - }); - - if self.funding_tx_confirmations > 0 { - self.funding_tx_confirmations += 1; - } - + pub fn transactions_confirmed(&mut self, block_hash: &BlockHash, height: u32, txdata: &TransactionData) -> Result<(), msgs::ErrorMessage> { let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS); if non_shutdown_state & !(ChannelState::TheirFundingLocked as u32) == ChannelState::FundingSent as u32 { for &(index_in_block, tx) in txdata.iter() { @@ -3550,22 +3537,63 @@ impl Channel { } } } - if height > 0xff_ff_ff || (index_in_block) > 0xff_ff_ff { - panic!("Block was bogus - either height 16 million or had > 16 million transactions"); + self.funding_tx_confirmation_height = height as u64; + self.funding_tx_confirmed_in = Some(*block_hash); + self.short_channel_id = match scid_from_parts(height as u64, index_in_block as u64, txo_idx as u64) { + Ok(scid) => Some(scid), + Err(_) => panic!("Block was bogus - either height was > 16 million, had > 16 million transactions, or had > 65k outputs"), } - assert!(txo_idx <= 0xffff); // txo_idx is a (u16 as usize), so this is just listed here for completeness - self.funding_tx_confirmations = 1; - self.short_channel_id = Some(((height as u64) << (5*8)) | - ((index_in_block as u64) << (2*8)) | - ((txo_idx as u64) << (0*8))); } } } } + Ok(()) + } + + /// When a new block is connected, we check the height of the block against outbound holding + /// cell HTLCs in case we need to give up on them prematurely and time them out. Everything + /// else (e.g. commitment transaction broadcasts, HTLC transaction broadcasting, etc) is + /// handled by the ChannelMonitor. + /// + /// If we return Err, the channel may have been closed, at which point the standard + /// requirements apply - no calls may be made except those explicitly stated to be allowed + /// post-shutdown. + /// + /// May return some HTLCs (and their payment_hash) which have timed out and should be failed + /// back. + pub fn update_best_block(&mut self, height: u32, highest_header_time: u32) -> Result<(Option, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage> { + let mut timed_out_htlcs = Vec::new(); + let unforwarded_htlc_cltv_limit = height + HTLC_FAIL_BACK_BUFFER; + self.holding_cell_htlc_updates.retain(|htlc_update| { + match htlc_update { + &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, ref cltv_expiry, .. } => { + if *cltv_expiry <= unforwarded_htlc_cltv_limit { + timed_out_htlcs.push((source.clone(), payment_hash.clone())); + false + } else { true } + }, + _ => true + } + }); - self.update_time_counter = cmp::max(self.update_time_counter, header.time); - if self.funding_tx_confirmations > 0 { - if self.funding_tx_confirmations == self.minimum_depth as u64 { + self.update_time_counter = cmp::max(self.update_time_counter, highest_header_time); + if self.funding_tx_confirmation_height > 0 { + let funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1; + if funding_tx_confirmations <= 0 { + self.funding_tx_confirmation_height = 0; + } + + let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS); + if (non_shutdown_state >= ChannelState::ChannelFunded as u32 || + (non_shutdown_state & ChannelState::OurFundingLocked as u32) == ChannelState::OurFundingLocked as u32) && + funding_tx_confirmations < self.minimum_depth as i64 / 2 { + return Err(msgs::ErrorMessage { + channel_id: self.channel_id(), + data: format!("Funding transaction was un-confirmed. Locked at {} confs, now have {} confs.", self.minimum_depth, funding_tx_confirmations), + }); + } + + if funding_tx_confirmations == self.minimum_depth as i64 { let need_commitment_update = if non_shutdown_state == ChannelState::FundingSent as u32 { self.channel_state |= ChannelState::OurFundingLocked as u32; true @@ -3584,7 +3612,6 @@ impl Channel { // funding_tx_confirmed_in and return. false }; - self.funding_tx_confirmed_in = Some(header.block_hash()); //TODO: Note that this must be a duplicate of the previous commitment point they sent us, //as otherwise we will have a commitment transaction that they can't revoke (well, kinda, @@ -3604,21 +3631,35 @@ impl Channel { } } } + Ok((None, timed_out_htlcs)) } + /// When we receive a new block, we (a) check whether the block contains the funding + /// transaction (which would start us counting blocks until we send the funding_signed), and + /// (b) check the height of the block against outbound holding cell HTLCs in case we need to + /// give up on them prematurely and time them out. Everything else (e.g. commitment + /// transaction broadcasts, channel closure detection, HTLC transaction broadcasting, etc) is + /// handled by the ChannelMonitor. + /// + /// If we return Err, the channel may have been closed, at which point the standard + /// requirements apply - no calls may be made except those explicitly stated to be allowed + /// post-shutdown. + /// Only returns an ErrorAction of DisconnectPeer, if Err. + /// + /// May return some HTLCs (and their payment_hash) which have timed out and should be failed + /// back. + pub fn block_connected(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32) -> Result<(Option, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage> { + self.transactions_confirmed(&header.block_hash(), height, txdata)?; + self.update_best_block(height, header.time) + } + /// Called by channelmanager based on chain blocks being disconnected. /// Returns true if we need to close the channel now due to funding transaction /// unconfirmation/reorg. - pub fn block_disconnected(&mut self, header: &BlockHeader) -> bool { - if self.funding_tx_confirmations > 0 { - self.funding_tx_confirmations -= 1; - if self.funding_tx_confirmations == UNCONF_THRESHOLD as u64 { - return true; - } - } - if Some(header.block_hash()) == self.funding_tx_confirmed_in { - self.funding_tx_confirmations = self.minimum_depth as u64 - 1; + pub fn block_disconnected(&mut self, header: &BlockHeader, new_height: u32) -> bool { + if self.update_best_block(new_height, header.time).is_err() { + return true; } false } @@ -4114,6 +4155,25 @@ impl Channel { } } + /// Get forwarding information for the counterparty. + pub fn counterparty_forwarding_info(&self) -> Option { + self.counterparty_forwarding_info.clone() + } + + pub fn channel_update(&mut self, msg: &msgs::ChannelUpdate) -> Result<(), ChannelError> { + let usable_channel_value_msat = (self.channel_value_satoshis - self.counterparty_selected_channel_reserve_satoshis) * 1000; + if msg.contents.htlc_minimum_msat >= usable_channel_value_msat { + return Err(ChannelError::Close("Minimum htlc value is greater than channel value".to_string())); + } + self.counterparty_forwarding_info = Some(CounterpartyForwardingInfo { + fee_base_msat: msg.contents.fee_base_msat, + fee_proportional_millionths: msg.contents.fee_proportional_millionths, + cltv_expiry_delta: msg.contents.cltv_expiry_delta + }); + + Ok(()) + } + /// Begins the shutdown process, getting a message for the remote peer and returning all /// holding cell HTLCs for payment failure. pub fn get_shutdown(&mut self) -> Result<(msgs::Shutdown, Vec<(HTLCSource, PaymentHash)>), APIError> { @@ -4425,8 +4485,8 @@ impl Writeable for Channel { } self.funding_tx_confirmed_in.write(writer)?; + self.funding_tx_confirmation_height.write(writer)?; self.short_channel_id.write(writer)?; - self.funding_tx_confirmations.write(writer)?; self.counterparty_dust_limit_satoshis.write(writer)?; self.holder_dust_limit_satoshis.write(writer)?; @@ -4437,6 +4497,16 @@ impl Writeable for Channel { self.counterparty_max_accepted_htlcs.write(writer)?; self.minimum_depth.write(writer)?; + match &self.counterparty_forwarding_info { + Some(info) => { + 1u8.write(writer)?; + info.fee_base_msat.write(writer)?; + info.fee_proportional_millionths.write(writer)?; + info.cltv_expiry_delta.write(writer)?; + }, + None => 0u8.write(writer)? + } + self.channel_transaction_parameters.write(writer)?; self.counterparty_cur_commitment_point.write(writer)?; @@ -4585,8 +4655,8 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel }; let funding_tx_confirmed_in = Readable::read(reader)?; + let funding_tx_confirmation_height = Readable::read(reader)?; let short_channel_id = Readable::read(reader)?; - let funding_tx_confirmations = Readable::read(reader)?; let counterparty_dust_limit_satoshis = Readable::read(reader)?; let holder_dust_limit_satoshis = Readable::read(reader)?; @@ -4597,6 +4667,16 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel let counterparty_max_accepted_htlcs = Readable::read(reader)?; let minimum_depth = Readable::read(reader)?; + let counterparty_forwarding_info = match ::read(reader)? { + 0 => None, + 1 => Some(CounterpartyForwardingInfo { + fee_base_msat: Readable::read(reader)?, + fee_proportional_millionths: Readable::read(reader)?, + cltv_expiry_delta: Readable::read(reader)?, + }), + _ => return Err(DecodeError::InvalidValue), + }; + let channel_parameters = Readable::read(reader)?; let counterparty_cur_commitment_point = Readable::read(reader)?; @@ -4655,8 +4735,8 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel last_sent_closing_fee, funding_tx_confirmed_in, + funding_tx_confirmation_height, short_channel_id, - funding_tx_confirmations, counterparty_dust_limit_satoshis, holder_dust_limit_satoshis, @@ -4667,6 +4747,8 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel counterparty_max_accepted_htlcs, minimum_depth, + counterparty_forwarding_info, + channel_transaction_parameters: channel_parameters, counterparty_cur_commitment_point, @@ -4702,7 +4784,7 @@ mod tests { use ln::channel::{Channel,Sign,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,HTLCCandidate,HTLCInitiator,TxCreationKeys}; use ln::channel::MAX_FUNDING_SATOSHIS; use ln::features::InitFeatures; - use ln::msgs::{OptionalField, DataLossProtect, DecodeError}; + use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate}; use ln::chan_utils; use ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT}; use chain::chaininterface::{FeeEstimator,ConfirmationTarget}; @@ -4713,6 +4795,7 @@ mod tests { use util::test_utils; use util::logger::Logger; use bitcoin::secp256k1::{Secp256k1, Message, Signature, All}; + use bitcoin::secp256k1::ffi::Signature as FFISignature; use bitcoin::secp256k1::key::{SecretKey,PublicKey}; use bitcoin::hashes::sha256::Hash as Sha256; use bitcoin::hashes::Hash; @@ -4969,6 +5052,54 @@ mod tests { } } + #[test] + fn channel_update() { + let feeest = TestFeeEstimator{fee_est: 15000}; + let secp_ctx = Secp256k1::new(); + let seed = [42; 32]; + let network = Network::Testnet; + let chain_hash = genesis_block(network).header.block_hash(); + let keys_provider = test_utils::TestKeysInterface::new(&seed, network); + + // Create a channel. + let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()); + let config = UserConfig::default(); + let mut node_a_chan = Channel::::new_outbound(&&feeest, &&keys_provider, node_b_node_id, 10000000, 100000, 42, &config).unwrap(); + assert!(node_a_chan.counterparty_forwarding_info.is_none()); + assert_eq!(node_a_chan.holder_htlc_minimum_msat, 1); // the default + assert!(node_a_chan.counterparty_forwarding_info().is_none()); + + // Make sure that receiving a channel update will update the Channel as expected. + let update = ChannelUpdate { + contents: UnsignedChannelUpdate { + chain_hash, + short_channel_id: 0, + timestamp: 0, + flags: 0, + cltv_expiry_delta: 100, + htlc_minimum_msat: 5, + htlc_maximum_msat: OptionalField::Absent, + fee_base_msat: 110, + fee_proportional_millionths: 11, + excess_data: Vec::new(), + }, + signature: Signature::from(unsafe { FFISignature::new() }) + }; + node_a_chan.channel_update(&update).unwrap(); + + // The counterparty can send an update with a higher minimum HTLC, but that shouldn't + // change our official htlc_minimum_msat. + assert_eq!(node_a_chan.holder_htlc_minimum_msat, 1); + match node_a_chan.counterparty_forwarding_info() { + Some(info) => { + assert_eq!(info.cltv_expiry_delta, 100); + assert_eq!(info.fee_base_msat, 110); + assert_eq!(info.fee_proportional_millionths, 11); + }, + None => panic!("expected counterparty forwarding info to be Some") + } + } + #[test] fn outbound_commitment_test() { // Test vectors from BOLT 3 Appendix C: