From: Duncan Dean Date: Tue, 12 Sep 2023 19:23:51 +0000 (+0200) Subject: Add `InboundV2Channel` struct X-Git-Tag: v0.0.123-beta~60^2~4 X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=fd68df9f95f92a4bc8394c1667d276ef41df7f08;p=rust-lightning Add `InboundV2Channel` struct --- diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index ed2350839..4446801ed 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -3191,6 +3191,19 @@ pub(crate) fn get_legacy_default_holder_selected_channel_reserve_satoshis(channe cmp::min(channel_value_satoshis, cmp::max(q, 1000)) } +/// Returns a minimum channel reserve value each party needs to maintain, fixed in the spec to a +/// default of 1% of the total channel value. +/// +/// Guaranteed to return a value no larger than channel_value_satoshis +/// +/// This is used both for outbound and inbound channels and has lower bound +/// of `dust_limit_satoshis`. +fn get_v2_channel_reserve_satoshis(channel_value_satoshis: u64, dust_limit_satoshis: u64) -> u64 { + // Fixed at 1% of channel value by spec. + let (q, _) = channel_value_satoshis.overflowing_div(100); + cmp::min(channel_value_satoshis, cmp::max(q, dust_limit_satoshis)) +} + // Get the fee cost in SATS of a commitment tx with a given number of HTLC outputs. // Note that num_htlcs should not include dust HTLCs. #[inline] @@ -3224,6 +3237,8 @@ pub(super) struct DualFundingChannelContext { // Counterparty designates channel data owned by the another channel participant entity. pub(super) struct Channel where SP::Target: SignerProvider { pub context: ChannelContext, + #[cfg(dual_funding)] + pub dual_funding_channel_context: Option, } #[cfg(any(test, fuzzing))] @@ -7554,7 +7569,11 @@ impl OutboundV1Channel where SP::Target: SignerProvider { log_info!(logger, "Received funding_signed from peer for channel {}", &self.context.channel_id()); - let mut channel = Channel { context: self.context }; + let mut channel = Channel { + context: self.context, + #[cfg(dual_funding)] + dual_funding_channel_context: None, + }; let need_channel_ready = channel.check_get_channel_ready(0).is_some(); channel.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new()); @@ -7579,12 +7598,12 @@ pub(super) struct InboundV1Channel where SP::Target: SignerProvider { } /// Fetches the [`ChannelTypeFeatures`] that will be used for a channel built from a given -/// [`msgs::OpenChannel`]. +/// [`msgs::CommonOpenChannelFields`]. pub(super) fn channel_type_from_open_channel( - msg: &msgs::OpenChannel, their_features: &InitFeatures, + common_fields: &msgs::CommonOpenChannelFields, their_features: &InitFeatures, our_supported_features: &ChannelTypeFeatures ) -> Result { - if let Some(channel_type) = &msg.common_fields.channel_type { + if let Some(channel_type) = &common_fields.channel_type { if channel_type.supports_any_optional_bits() { return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned())); } @@ -7599,7 +7618,7 @@ pub(super) fn channel_type_from_open_channel( if !channel_type.is_subset(our_supported_features) { return Err(ChannelError::Close("Channel Type contains unsupported features".to_owned())); } - let announced_channel = if (msg.common_fields.channel_flags & 1) == 1 { true } else { false }; + let announced_channel = if (common_fields.channel_flags & 1) == 1 { true } else { false }; if channel_type.requires_scid_privacy() && announced_channel { return Err(ChannelError::Close("SCID Alias/Privacy Channel Type cannot be set on a public channel".to_owned())); } @@ -7630,7 +7649,7 @@ impl InboundV1Channel where SP::Target: SignerProvider { // First check the channel type is known, failing before we do anything else if we don't // support this channel type. - let channel_type = channel_type_from_open_channel(msg, their_features, our_supported_features)?; + let channel_type = channel_type_from_open_channel(&msg.common_fields, their_features, our_supported_features)?; let holder_selected_channel_reserve_satoshis = get_holder_selected_channel_reserve_satoshis(msg.common_fields.funding_satoshis, config); let counterparty_pubkeys = ChannelPublicKeys { @@ -7842,6 +7861,8 @@ impl InboundV1Channel where SP::Target: SignerProvider { // `ChannelMonitor`. let mut channel = Channel { context: self.context, + #[cfg(dual_funding)] + dual_funding_channel_context: None, }; let need_channel_ready = channel.check_get_channel_ready(0).is_some(); channel.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new()); @@ -7850,6 +7871,160 @@ impl InboundV1Channel where SP::Target: SignerProvider { } } +// A not-yet-funded inbound (from counterparty) channel using V2 channel establishment. +#[cfg(dual_funding)] +pub(super) struct InboundV2Channel where SP::Target: SignerProvider { + pub context: ChannelContext, + pub unfunded_context: UnfundedChannelContext, + pub dual_funding_context: DualFundingChannelContext, +} + +#[cfg(dual_funding)] +impl InboundV2Channel where SP::Target: SignerProvider { + /// Creates a new dual-funded channel from a remote side's request for one. + /// Assumes chain_hash has already been checked and corresponds with what we expect! + pub fn new( + fee_estimator: &LowerBoundedFeeEstimator, entropy_source: &ES, signer_provider: &SP, + counterparty_node_id: PublicKey, our_supported_features: &ChannelTypeFeatures, + their_features: &InitFeatures, msg: &msgs::OpenChannelV2, funding_satoshis: u64, user_id: u128, + config: &UserConfig, current_chain_height: u32, logger: &L, + ) -> Result, ChannelError> + where ES::Target: EntropySource, + F::Target: FeeEstimator, + L::Target: Logger, + { + let channel_value_satoshis = funding_satoshis.saturating_add(msg.common_fields.funding_satoshis); + let counterparty_selected_channel_reserve_satoshis = get_v2_channel_reserve_satoshis( + channel_value_satoshis, msg.common_fields.dust_limit_satoshis); + let holder_selected_channel_reserve_satoshis = get_v2_channel_reserve_satoshis( + channel_value_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS); + + // First check the channel type is known, failing before we do anything else if we don't + // support this channel type. + if msg.common_fields.channel_type.is_none() { + return Err(ChannelError::Close(format!("Rejecting V2 channel {} missing channel_type", + msg.common_fields.temporary_channel_id))) + } + let channel_type = channel_type_from_open_channel(&msg.common_fields, their_features, our_supported_features)?; + + let counterparty_pubkeys = ChannelPublicKeys { + funding_pubkey: msg.common_fields.funding_pubkey, + revocation_basepoint: RevocationBasepoint(msg.common_fields.revocation_basepoint), + payment_point: msg.common_fields.payment_basepoint, + delayed_payment_basepoint: DelayedPaymentBasepoint(msg.common_fields.delayed_payment_basepoint), + htlc_basepoint: HtlcBasepoint(msg.common_fields.htlc_basepoint) + }; + + let mut context = ChannelContext::new_for_inbound_channel( + fee_estimator, + entropy_source, + signer_provider, + counterparty_node_id, + their_features, + user_id, + config, + current_chain_height, + logger, + false, + + funding_satoshis, + + counterparty_pubkeys, + channel_type, + holder_selected_channel_reserve_satoshis, + counterparty_selected_channel_reserve_satoshis, + 0 /* push_msat not used in dual-funding */, + msg.common_fields.clone(), + )?; + let channel_id = ChannelId::v2_from_revocation_basepoints( + &context.get_holder_pubkeys().revocation_basepoint, + &context.get_counterparty_pubkeys().revocation_basepoint); + context.channel_id = channel_id; + + let chan = Self { + context, + unfunded_context: UnfundedChannelContext { unfunded_channel_age_ticks: 0 }, + dual_funding_context: DualFundingChannelContext { + our_funding_satoshis: funding_satoshis, + their_funding_satoshis: msg.common_fields.funding_satoshis, + funding_tx_locktime: msg.locktime, + funding_feerate_sat_per_1000_weight: msg.funding_feerate_sat_per_1000_weight, + } + }; + + Ok(chan) + } + + /// Marks an inbound channel as accepted and generates a [`msgs::AcceptChannelV2`] message which + /// should be sent back to the counterparty node. + /// + /// [`msgs::AcceptChannelV2`]: crate::ln::msgs::AcceptChannelV2 + pub fn accept_inbound_dual_funded_channel(&mut self) -> msgs::AcceptChannelV2 { + if self.context.is_outbound() { + debug_assert!(false, "Tried to send accept_channel for an outbound channel?"); + } + if !matches!( + self.context.channel_state, ChannelState::NegotiatingFunding(flags) + if flags == (NegotiatingFundingFlags::OUR_INIT_SENT | NegotiatingFundingFlags::THEIR_INIT_SENT) + ) { + debug_assert!(false, "Tried to send accept_channel2 after channel had moved forward"); + } + if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { + debug_assert!(false, "Tried to send an accept_channel2 for a channel that has already advanced"); + } + + self.generate_accept_channel_v2_message() + } + + /// This function is used to explicitly generate a [`msgs::AcceptChannel`] message for an + /// inbound channel. If the intention is to accept an inbound channel, use + /// [`InboundV1Channel::accept_inbound_channel`] instead. + /// + /// [`msgs::AcceptChannelV2`]: crate::ln::msgs::AcceptChannelV2 + fn generate_accept_channel_v2_message(&self) -> msgs::AcceptChannelV2 { + let first_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point( + self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx); + let second_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point( + self.context.cur_holder_commitment_transaction_number - 1, &self.context.secp_ctx); + let keys = self.context.get_holder_pubkeys(); + + msgs::AcceptChannelV2 { + common_fields: msgs::CommonAcceptChannelFields { + temporary_channel_id: self.context.temporary_channel_id.unwrap(), + dust_limit_satoshis: self.context.holder_dust_limit_satoshis, + max_htlc_value_in_flight_msat: self.context.holder_max_htlc_value_in_flight_msat, + htlc_minimum_msat: self.context.holder_htlc_minimum_msat, + minimum_depth: self.context.minimum_depth.unwrap(), + to_self_delay: self.context.get_holder_selected_contest_delay(), + max_accepted_htlcs: self.context.holder_max_accepted_htlcs, + funding_pubkey: keys.funding_pubkey, + revocation_basepoint: keys.revocation_basepoint.to_public_key(), + payment_basepoint: keys.payment_point, + delayed_payment_basepoint: keys.delayed_payment_basepoint.to_public_key(), + htlc_basepoint: keys.htlc_basepoint.to_public_key(), + first_per_commitment_point, + shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey { + Some(script) => script.clone().into_inner(), + None => Builder::new().into_script(), + }), + channel_type: Some(self.context.channel_type.clone()), + }, + funding_satoshis: self.dual_funding_context.our_funding_satoshis, + second_per_commitment_point, + require_confirmed_inputs: None, + } + } + + /// Enables the possibility for tests to extract a [`msgs::AcceptChannelV2`] message for an + /// inbound channel without accepting it. + /// + /// [`msgs::AcceptChannelV2`]: crate::ln::msgs::AcceptChannelV2 + #[cfg(test)] + pub fn get_accept_channel_v2_message(&self) -> msgs::AcceptChannelV2 { + self.generate_accept_channel_v2_message() + } +} + const SERIALIZATION_VERSION: u8 = 3; const MIN_SERIALIZATION_VERSION: u8 = 3; @@ -8793,7 +8968,9 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch local_initiated_shutdown, blocked_monitor_updates: blocked_monitor_updates.unwrap(), - } + }, + #[cfg(dual_funding)] + dual_funding_channel_context: None, }) } } diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index 55b2cbae4..4d8fbdbbf 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -6247,7 +6247,7 @@ where // If we're doing manual acceptance checks on the channel, then defer creation until we're sure we want to accept. if self.default_configuration.manually_accept_inbound_channels { let channel_type = channel::channel_type_from_open_channel( - &msg, &peer_state.latest_features, &self.channel_type_features() + &msg.common_fields, &peer_state.latest_features, &self.channel_type_features() ).map_err(|e| MsgHandleErrInternal::from_chan_no_close(e, msg.common_fields.temporary_channel_id) )?;